The Microwave SQUID Multiplexer

NASA Astrophysics Data System (ADS)

Mates, John Arthur Benson

2011-12-01

This thesis describes a multiplexer of Superconducting Quantum Interference Devices (SQUIDs) with low-noise, ultra-low power dissipation, and great scalability. The multiplexer circuit measures the magnetic flux in a large number of unshunted rf SQUIDs by coupling each SQUID to a superconducting microwave resonator tuned to a unique resonance frequency and driving the resonators from a common feedline. A superposition of microwave tones measures each SQUID simultaneously using only two coaxial cables between the cryogenic device and room temperature. This multiplexer will enable the instrumentation of arrays with hundreds of thousands of low-temperature detectors for new applications in cosmology, materials analysis, and nuclear non-proliferation. The driving application of the Microwave SQUID Multiplexer is the readout of large arrays of superconducting transition-edge sensors, by some figures of merit the most sensitive detectors of electromagnetic signals over a span of more than nine orders of magnitude in energy, from 40 GHz microwaves to 200 keV gamma rays. Modern transition-edge sensors have noise-equivalent power as low as 10-20 W / Hz1/2 and energy resolution as good as 2 eV at 6 keV. These per-pixel sensitivities approach theoretical limits set by the underlying signals, motivating a rapid increase in pixel count to access new science. Compelling applications, like the non-destructive assay of nuclear material for treaty verification or the search for primordial gravity waves from inflation use arrays of these detectors to increase collection area or tile a focal plane. We developed three generations of SQUID multiplexers, optimizing the first for flux noise 0.17 muPhi0 / Hz1/2, the second for input current noise 19 pA / Hz1/2, and the last for practical multiplexing of large arrays of cosmic microwave background polarimeters based on transition-edge sensors. Using the last design we demonstrated multiplexed readout of prototype polarimeters with the performance required for the future development of a large-scale astronomical instrument.

First Tests of Prototype SCUBA-2 Superconducting Bolometer Array

NASA Astrophysics Data System (ADS)

Woodcraft, Adam L.; Ade, Peter A. R.; Bintley, Dan; Hunt, Cynthia L.; Sudiwala, Rashmi V.; Hilton, Gene C.; Irwin, Kent D.; Reintsema, Carl D.; Audley, Michael D.; Holland, Wayne S.; MacIntosh, Mike

2006-09-01

We present results of the first tests on a 1280 pixel superconducting bolometer array, a prototype for SCUBA-2, a sub-mm camera being built for the James Clerk Maxwell Telescope in Hawaii. The bolometers are TES (transition edge sensor) detectors; these take advantage of the large variation of resistance with temperature through the superconducting transition. To keep the number of wires reasonable, a multiplexed read-out is used. Each pixel is read out through an individual DC SQUID; room temperature electronics switch between rows in the array by biasing the appropriate SQUIDs in turn. Arrays of 100 SQUIDs in series for each column then amplify the output. Unlike previous TES arrays, the multiplexing elements are located beneath each pixel, making large arrays possible, but construction more challenging. The detectors are constructed from Mo/Cu bi-layers; this technique enables the transition temperature to be tuned using the proximity effect by choosing the thickness of the normal and superconducting materials. To achieve the required performance, the detectors are operated at a temperature of approximately 120 mK. We describe the results of a basic characterisation of the array, demonstrating that it is fully operational, and give the results of signal to noise measurements.

Modeling the Effects of Varying the Capacitance, Resistance, Temperature, and Frequency Dependence for HTS Josephson Junctions, DC SQUIDs and DC bi-SQUIDS

DTIC Science & Technology

2014-09-01

junction is a thin layer of insulating material sep- arating two superconductors that is thin enough for electrons to tunnel through. Two Josephson...can sense minute magnetic fields approaching 1015 Tesla. These SQUIDs can be arranged in arrays with different coupling schemes and parameter values to...different material and/or method on the bisecting Josephson junction for high temperature superconductor (HTS) YBa2Cu3O7 (YBCO) bi-SQUIDs. This

Microwave SQUID Multiplexer for the Readout of Metallic Magnetic Calorimeters

NASA Astrophysics Data System (ADS)

Kempf, S.; Gastaldo, L.; Fleischmann, A.; Enss, C.

2014-06-01

We have realized a frequency-domain multiplexing technique for the readout of large metallic magnetic calorimeter detector arrays. It is based on non-hysteretic single-junction SQUIDs and allows for a simultaneous readout of hundreds or thousands of detectors by using a single cryogenic high electron mobility transistor amplifier and two coaxial cables that are routed from room-temperature to the detector array. We discuss the working principle of the multiplexer and present details about our prototype multiplexer design. We show that fabricated devices are fully operational and that characteristic SQUID parameters such as the input sensitivity of the SQUID or the resonance frequency of the readout circuit can be predicted with confidence. Our best device so far has shown a magnetic flux white noise level of 1.4 m which can in future be reduced by an optimization of the fabrication processes as well as an improved microwave readout system.

Scanning SQUID sampler with 40-ps time resolution

NASA Astrophysics Data System (ADS)

Cui, Zheng; Kirtley, John R.; Wang, Yihua; Kratz, Philip A.; Rosenberg, Aaron J.; Watson, Christopher A.; Gibson, Gerald W.; Ketchen, Mark B.; Moler, Kathryn. A.

2017-08-01

Scanning Superconducting QUantum Interference Device (SQUID) microscopy provides valuable information about magnetic properties of materials and devices. The magnetic flux response of the SQUID is often linearized with a flux-locked feedback loop, which limits the response time to microseconds or longer. In this work, we present the design, fabrication, and characterization of a novel scanning SQUID sampler with a 40-ps time resolution and linearized response to periodically triggered signals. Other design features include a micron-scale pickup loop for the detection of local magnetic flux, a field coil to apply a local magnetic field to the sample, and a modulation coil to operate the SQUID sampler in a flux-locked loop to linearize the flux response. The entire sampler device is fabricated on a 2 mm × 2 mm chip and can be scanned over macroscopic planar samples. The flux noise at 4.2 K with 100 kHz repetition rate and 1 s of averaging is of order 1 mΦ0. This SQUID sampler will be useful for imaging dynamics in magnetic and superconducting materials and devices.

Scanning SQUID sampler with 40-ps time resolution.

PubMed

Cui, Zheng; Kirtley, John R; Wang, Yihua; Kratz, Philip A; Rosenberg, Aaron J; Watson, Christopher A; Gibson, Gerald W; Ketchen, Mark B; Moler, Kathryn A

2017-08-01

Scanning Superconducting QUantum Interference Device (SQUID) microscopy provides valuable information about magnetic properties of materials and devices. The magnetic flux response of the SQUID is often linearized with a flux-locked feedback loop, which limits the response time to microseconds or longer. In this work, we present the design, fabrication, and characterization of a novel scanning SQUID sampler with a 40-ps time resolution and linearized response to periodically triggered signals. Other design features include a micron-scale pickup loop for the detection of local magnetic flux, a field coil to apply a local magnetic field to the sample, and a modulation coil to operate the SQUID sampler in a flux-locked loop to linearize the flux response. The entire sampler device is fabricated on a 2 mm × 2 mm chip and can be scanned over macroscopic planar samples. The flux noise at 4.2 K with 100 kHz repetition rate and 1 s of averaging is of order 1 mΦ 0 . This SQUID sampler will be useful for imaging dynamics in magnetic and superconducting materials and devices.

Performance of a novel SQUID-based superconducting imaging-surface magnetoencephalography system

NASA Astrophysics Data System (ADS)

Kraus, R. H.; Volegov, P.; Maharajh, K.; Espy, M. A.; Matlashov, A. N.; Flynn, E. R.

2002-03-01

Performance for a recently completed whole-head magnetoencephalography system using a superconducting imaging surface (SIS) surrounding an array of 150 SQUID magnetometers is reported. The helmet-like SIS is hemispherical in shape with a brim. Conceptually, the SIS images nearby sources onto the SQUIDs while shielding sensors from distant “noise” sources. A finite element method (FEM) description using the as-built geometry was developed to describe the SIS effect on source fields by imposing B⊥( surface)=0 . Sensors consist of 8×8 mm 2 SQUID magnetometers with 0.84 nT/ Φ0 sensitivity and <3 fT/ Hz noise. A series of phantom experiments to verify system efficacy have been completed. Simple dry-wire phantoms were used to eliminate model dependence from our results. Phantom coils were distributed throughout the volume encompassed by the array with a variety of orientations. Each phantom coil was precisely machined and located to better than 25 μm and 10 mRad accuracy. Excellent agreement between model-calculated and measured magnetic field distributions of all phantom coil positions and orientations was found. Good agreement was found between modeled and measured shielding of the SQUIDs from sources external to the array showing significant frequency-independent shielding. Phantom localization precision was better than 0.5 mm at all locations with a mean of better than 0.3 mm.

Computational and Mathematical Modeling of Coupled Superconducting Quantum Interference Devices

NASA Astrophysics Data System (ADS)

Berggren, Susan Anne Elizabeth

This research focuses on conducting an extensive computational investigation and mathematical analysis into the average voltage response of arrays of Superconducting Quantum Interference Devices (SQUIDs). These arrays will serve as the basis for the development of a sensitive, low noise, significantly lower Size, Weight and Power (SWaP) antenna integrated with Low-Noise Amplifier (LNA) using the SQUID technology. The goal for this antenna is to be capable of meeting all requirements for Guided Missile Destroyers (DDG) 1000 class ships for Information Operations/Signals Intelligence (IO/SIGINT) applications in Very High Frequency/Ultra High Frequency (V/UHF) bands. The device will increase the listening capability of receivers by moving technology into a new regime of energy detection allowing wider band, smaller size, more sensitive, stealthier systems. The smaller size and greater sensitivity will allow for ships to be “de-cluttered” of their current large dishes and devices, replacing everything with fewer and smaller SQUID antenna devices. The fewer devices present on the deck of a ship, the more invisible the ship will be to enemy forces. We invent new arrays of SQUIDs, optimized for signal detection with very high dynamic range and excellent spur-free dynamic range, while maintaining extreme small size (and low radar cross section), wide bandwidth, and environmentally noise limited sensitivity, effectively shifting the bottle neck of receiver systems forever away from the antenna itself deeper into the receiver chain. To accomplish these goals we develop and validate mathematical models for different designs of SQUID arrays and use them to invent a new device and systems design. This design is capable of significantly exceeding, per size weight and power, state-of-the-art receiver system measures of performance, such as bandwidth, sensitivity, dynamic range, and spurious-free dynamic range.

Onshore-offshore movement of jumbo squid (Dosidicus gigas) on the continental shelf

NASA Astrophysics Data System (ADS)

Stewart, Julia S.; Gilly, William F.; Field, John C.; Payne, John C.

2013-10-01

Jumbo squid (Dosidicus gigas) have greatly extended their range in the California Current System, where they forage on a variety of ecologically and economically important species that inhabit both coastal and offshore mesopelagic regions. Swimming abilities and behavior are important factors in assessing the impacts of this range expansion, particularly in regard to foraging in conjunction with onshore-offshore movement over the continental shelf. Here we describe a study of horizontal movements by jumbo squid along and across the continental shelf off Washington, USA, using acoustic tags in association with the Census of Marine Life's Pacific Ocean Shelf Tracking Program (POST) receiver arrays. We detected frequent movements along the shelf break, movement onto the shelf at night, and no evidence of movement as a cohesive school. Our results demonstrate feasibility of using acoustic tags and arrays to document horizontal movements of jumbo squid along and across the continental shelf. This is important in order to determine how those movements overlap with those of other ecologically and commercially important fish species.

Design, fabrication and characterization of a 64 pixel metallic magnetic calorimeter array with integrated, on-chip microwave SQUID multiplexer

NASA Astrophysics Data System (ADS)

Kempf, S.; Wegner, M.; Deeg, L.; Fleischmann, A.; Gastaldo, L.; Herrmann, F.; Richter, D.; Enss, C.

2017-06-01

We report on the design, fabrication and characterization of a 64 pixel metallic magnetic calorimeter array that is read out by an integrated, on-chip microwave SQUID multiplexer. Based on the results of our comprehensive device characterization we refined the state-of-the-art multiplexer model which assumes each associated non-hysteretic rf-SQUID to purely behave as a flux-dependent inductor. In particular, we include the capacitance and the subgap resistance of the Josephson junction as well as screening effects and parasitic mutual couplings between different coils that show up only when a superconducting flux transformer is attached to the SQUID input. Thanks to these modifications, we are able to explain the occurrence of a magnetic flux dependence of the internal quality factor of the microwave resonators as well as to accurately calculate the characteristic multiplexer parameters. When combining the refined multiplexer model with the thermodynamical description of a metallic magnetic calorimeter, we find a reasonable agreement between our measurements and predictions.

Enhancements to a Superconducting Quantum Interference Device (SQUID) Multiplexer Readout and Control System

NASA Technical Reports Server (NTRS)

Forgione, J.; Benford, D. J.; Buchanan, E. D.; Moseley, S. H.; Rebar, J.; Shafer, R. A.

2004-01-01

Far-infrared detector arrays such as the 16x32 superconducting bolometer array for the SAFIRE instrument (flying on the SOFIA airborne observatory) require systems of readout and control electronics to provide translation between a user-driven, digital PC and the cold, analog world of the cryogenic detector. In 2001, the National Institute of Standards and Technology (NIST) developed their Mark III electronics for purposes of control and readout of their 1x32 SQUID Multiplexer chips. We at NASA s Goddard Space Flight Center acquired a Mark 111 system and subsequently designed upgrades to suit our and our collaborators purposes. We developed an arbitrary, programmable multiplexing system that allows the user to cycle through rows in a SQUID array in an infinite number of combinations. We provided hooks in the Mark III system to allow readout of signals from outside the Mark 111 system, such as telescope status information. Finally, we augmented the heart of the system with a new feedback algorithm implementation, flexible diagnostic tools, and informative telemetry.

Enhancements to a superconducting quantum interference device (SQUID) multiplexer readout and control system

NASA Astrophysics Data System (ADS)

Forgione, Joshua B.; Benford, Dominic J.; Buchanan, Ernest D.; Moseley, S. H., Jr.; Rebar, Joyce; Shafer, Richard A.

2004-10-01

Far-infrared detector arrays such as the 16x32 superconducting bolometer array for the SAFIRE instrument (flying on the SOFIA airborne observatory) require systems of readout and control electronics to provide translation between a user-driven, digital PC and the cold, analog world of the cryogenic detector. In 2001, the National Institute of Standards and Technology (NIST) developed their Mark III electronics for purposes of control and readout of their 1x32 SQUID Multiplexer chips. We at NASA's Goddard Space Flight Center acquired a Mark III system and subsequently designed upgrades to suit our and our collaborators' purposes. We developed an arbitrary, programmable multiplexing system that allows the user to cycle through rows in a SQUID array in an infinite number of combinations. We provided 'hooks' in the Mark III system to allow readout of signals from outside the Mark III system, such as telescope status information. Finally, we augmented the heart of the system with a new feedback algorithm implementation, flexible diagnostic tools, and informative telemetry.

Code-division-multiplexed readout of large arrays of TES microcalorimeters

NASA Astrophysics Data System (ADS)

Morgan, K. M.; Alpert, B. K.; Bennett, D. A.; Denison, E. V.; Doriese, W. B.; Fowler, J. W.; Gard, J. D.; Hilton, G. C.; Irwin, K. D.; Joe, Y. I.; O'Neil, G. C.; Reintsema, C. D.; Schmidt, D. R.; Ullom, J. N.; Swetz, D. S.

2016-09-01

Code-division multiplexing (CDM) offers a path to reading out large arrays of transition edge sensor (TES) X-ray microcalorimeters with excellent energy and timing resolution. We demonstrate the readout of X-ray TESs with a 32-channel flux-summed code-division multiplexing circuit based on superconducting quantum interference device (SQUID) amplifiers. The best detector has energy resolution of 2.28 ± 0.12 eV FWHM at 5.9 keV and the array has mean energy resolution of 2.77 ± 0.02 eV over 30 working sensors. The readout channels are sampled sequentially at 160 ns/row, for an effective sampling rate of 5.12 μs/channel. The SQUID amplifiers have a measured flux noise of 0.17 μΦ0/√Hz (non-multiplexed, referred to the first stage SQUID). The multiplexed noise level and signal slew rate are sufficient to allow readout of more than 40 pixels per column, making CDM compatible with requirements outlined for future space missions. Additionally, because the modulated data from the 32 SQUID readout channels provide information on each X-ray event at the row rate, our CDM architecture allows determination of the arrival time of an X-ray event to within 275 ns FWHM with potential benefits in experiments that require detection of near-coincident events.

Design and Performance of the Multiplexed SQUID/TES Array at Ninety Gigahertz

NASA Astrophysics Data System (ADS)

Stanchfield, Sara; Ade, Peter; Aguirre, James; Brevik, Justus A.; Cho, Hsiao-Mei; Datta, Rahul; Devlin, Mark; Dicker, Simon R.; Dober, Bradley; Duff, Shannon M.; Egan, Dennis; Ford, Pam; Hilton, Gene; Hubmayr, Johannes; Irwin, Kent; Knowles, Kenda; Marganian, Paul; Mason, Brian Scott; Mates, John A. B.; McMahon, Jeff; Mello, Melinda; Mroczkowski, Tony; Romero, Charles; Sievers, Jonathon; Tucker, Carole; Vale, Leila R.; Vissers, Michael; White, Steven; Whitehead, Mark; Ullom, Joel; Young, Alexander

2018-01-01

We present the array performance and astronomical images from early science results from MUSTANG-2, a 90 GHz feedhorn-coupled, microwave SQUID-multiplexed TES bolometer array operating on the Robert C. Byrd Green Bank Telescope (GBT). MUSTANG-2 was installed on the GBT on December 2, 2016 and immediately began commissioning efforts, followed by science observations, which are expected to conclude June 2017. The feedhorn and waveguide-probe-coupled detector technology is a mature technology, which has been used on instrument including the South Pole Telescope, the Atacama Cosmology Telescope, and the Atacama B-mode Search telescope. The microwave SQUID readout system developed for MUSTANG-2 currently reads out 66 detectors with a single coaxial cable and will eventually allow thousands of detectors to be multiplexed. This microwave SQUID multiplexer combines the proven abilities of millimeterwave TES detectors with the multiplexing capabilities of KIDs with no degradation in noise performance of the detectors. Each multiplexing device is read out using warm electronics consisting of a commercially available ROACH board, a DAC/ADC card, and an Intermediate Frequency mixer circuit. The hardware was originally developed by the UC Berkeley Collaboration for Astronomy Signal Processing and Electronic Research (CASPER) group, whose primary goal is to develop scalable FPGA-based hardware with the flexibility to be used in a wide range of radio signal processing applications. MUSTANG-2 is the first on-sky instrument to use microwave SQUID multiplexing and is available as a shared-risk/PI instrument on the GBT. In MUSTANG-2's first season 7 separate proposals were awarded a total of 230 hours of telescope time.

High-Resolution Displacement Sensor Using a SQUID Array Amplifier

NASA Technical Reports Server (NTRS)

Chui, Talso; Penanen, Konstantin; Barmatz, M.; Paik, Ho Jung

2004-01-01

Improvement in the measurement of displacement has profound implications for both exploration technologies and fundamental physics. For planetary exploration, the new SQUID-based capacitive displacement sensor will enable a more sensitive gravity gradiometer for mapping the interior of planets and moons. A new concept of a superfluid clock to be reported by Penanen and Chui at this workshop is also based on a high-resolution displacement sensor. Examples of high-impact physics projects that can benefit from a better displacement sensor are: detection of gravitational waves, test of the equivalence principle, search for the postulated "axion" particle, and test of the inverse square law of gravity. We describe the concept of a new displacement sensor that makes use of a recent development in the Superconducting Quantum Interference Device (SQUID) technology. The SQUID array amplifier, invented by Welty and Martinis (IEEE Trans. Appl. Superconductivity 3, 2605, 1993), has about the same noise as a conventional SQUID; however, it can work at a much higher frequency of up to 5 MHz. We explain how the higher bandwidth can be translated into higher resolution using a bridge-balancing scheme that can simultaneously balance out both the carrier signal at the bridge output and the electrostatic force acting on the test mass.

A Spread-Spectrum SQUID Multiplexer

NASA Astrophysics Data System (ADS)

Irwin, K. D.; Chaudhuri, S.; Cho, H.-M.; Dawson, C.; Kuenstner, S.; Li, D.; Titus, C. J.; Young, B. A.

2018-06-01

The transition-edge sensor (TES) is a mature, high-resolution x-ray spectrometer technology that provides a much higher efficiency than dispersive spectrometers such as gratings and crystal spectrometers. As larger arrays are developed, time-division multiplexing schemes operating at MHz frequencies are being replaced by microwave SQUID multiplexers using frequency-division multiplexing at GHz frequencies. However, the multiplexing factor achievable with microwave SQUIDs is limited by the high slew rate on the leading edge of x-ray pulses. In this paper, we propose a new multiplexing scheme for high-slew-rate TES x-ray calorimeters: the spread-spectrum SQUID multiplexer, which has the potential to enable higher multiplexing factors, especially in applications with lower photon-arrival rates.

Evaluation of realistic layouts for next generation on-scalp MEG: spatial information density maps.

PubMed

Riaz, Bushra; Pfeiffer, Christoph; Schneiderman, Justin F

2017-08-01

While commercial magnetoencephalography (MEG) systems are the functional neuroimaging state-of-the-art in terms of spatio-temporal resolution, MEG sensors have not changed significantly since the 1990s. Interest in newer sensors that operate at less extreme temperatures, e.g., high critical temperature (high-T c ) SQUIDs, optically-pumped magnetometers, etc., is growing because they enable significant reductions in head-to-sensor standoff (on-scalp MEG). Various metrics quantify the advantages of on-scalp MEG, but a single straightforward one is lacking. Previous works have furthermore been limited to arbitrary and/or unrealistic sensor layouts. We introduce spatial information density (SID) maps for quantitative and qualitative evaluations of sensor arrays. SID-maps present the spatial distribution of information a sensor array extracts from a source space while accounting for relevant source and sensor parameters. We use it in a systematic comparison of three practical on-scalp MEG sensor array layouts (based on high-T c SQUIDs) and the standard Elekta Neuromag TRIUX magnetometer array. Results strengthen the case for on-scalp and specifically high-T c SQUID-based MEG while providing a path for the practical design of future MEG systems. SID-maps are furthermore general to arbitrary magnetic sensor technologies and source spaces and can thus be used for design and evaluation of sensor arrays for magnetocardiography, magnetic particle imaging, etc.

SiGe Integrated Circuit Developments for SQUID/TES Readout

NASA Astrophysics Data System (ADS)

Prêle, D.; Voisin, F.; Beillimaz, C.; Chen, S.; Piat, M.; Goldwurm, A.; Laurent, P.

2018-03-01

SiGe integrated circuits dedicated to the readout of superconducting bolometer arrays for astrophysics have been developed since more than 10 years at APC. Whether for Cosmic Microwave Background (CMB) observations with the QUBIC ground-based experiment (Aumont et al. in astro-ph.IM, 2016. arXiv:1609.04372) or for the Hot and Energetic Universe science theme with the X-IFU instrument on-board of the ATHENA space mission (Barret et al. in SPIE 9905, space telescopes & instrumentation 2016: UV to γ Ray, 2016. https://doi.org/10.1117/12.2232432), several kinds of Transition Edge Sensor (TES) (Irwin and Hilton, in ENSS (ed) Cryogenic particle detection, Springer, Berlin, 2005) arrays have been investigated. To readout such superconducting detector arrays, we use time or frequency domain multiplexers (TDM, FDM) (Prêle in JINST 10:C08015, 2016. https://doi.org/10.1088/1748-0221/10/08/C08015) with Superconducting QUantum Interference Devices (SQUID). In addition to the SQUID devices, low-noise biasing and amplification are needed. These last functions can be obtained by using BiCMOS SiGe technology in an Application Specific Integrated Circuit (ASIC). ASIC technology allows integration of highly optimised circuits specifically designed for a unique application. Moreover, we could reach very low-noise and wide band amplification using SiGe bipolar transistor either at room or cryogenic temperatures (Cressler in J Phys IV 04(C6):C6-101, 1994. https://doi.org/10.1051/jp4:1994616). This paper discusses the use of SiGe integrated circuits for SQUID/TES readout and gives an update of the last developments dedicated to the QUBIC telescope and to the X-IFU instrument. Both ASIC called SQmux128 and AwaXe are described showing the interest of such SiGe technology for SQUID multiplexer controls.

Note: Increasing dynamic range of digital-to-analog converter using a superconducting quantum interference device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakanishi, Masakazu, E-mail: m.nakanishi@aist.go.jp

Responses of a superconducting quantum interference device (SQUID) are periodically dependent on magnetic flux coupling to its superconducting ring and the period is a flux quantum (Φ{sub o} = h/2e, where h and e, respectively, express Planck's constant and elementary charge). Using this periodicity, we had proposed a digital to analog converter using a SQUID (SQUID DAC) of first generation with linear current output, interval of which corresponded to Φ{sub o}. Modification for increasing dynamic range by interpolating within each interval is reported. Linearity of the interpolation was also based on the quantum periodicity. A SQUID DAC with dynamic rangemore » of about 1.4 × 10{sup 7} was created as a demonstration.« less

TES Detector Noise Limited Readout Using SQUID Multiplexers

NASA Technical Reports Server (NTRS)

Staguhn, J. G.; Benford, D. J.; Chervenak, J. A.; Khan, S. A.; Moseley, S. H.; Shafer, R. A.; Deiker, S.; Grossman, E. N.; Hilton, G. C.; Irwin, K. D.

2004-01-01

The availability of superconducting Transition Edge Sensors (TES) with large numbers of individual detector pixels requires multiplexers for efficient readout. The use of multiplexers reduces the number of wires needed between the cryogenic electronics and the room temperature electronics and cuts the number of required cryogenic amplifiers. We are using an 8 channel SQUID multiplexer to read out one-dimensional TES arrays which are used for submillimeter astronomical observations. We present results from test measurements which show that the low noise level of the SQUID multiplexers allows accurate measurements of the TES Johnson noise, and that in operation, the readout noise is dominated by the detector noise. Multiplexers for large number of channels require a large bandwidth for the multiplexed readout signal. We discuss the resulting implications for the noise performance of these multiplexers which will be used for the readout of two dimensional TES arrays in next generation instruments.

Far infrared through millimeter backshort-under-grid arrays

NASA Astrophysics Data System (ADS)

Allen, Christine A.; Abrahams, John; Benford, Dominic J.; Chervenak, James A.; Chuss, David T.; Staguhn, Johannes G.; Miller, Timothy M.; Moseley, S. Harvey; Wollack, Edward J.

2006-06-01

We are developing a large-format, versatile, bolometer array for a wide range of infrared through millimeter astronomical applications. The array design consists of three key components - superconducting transition edge sensor bolometer arrays, quarter-wave reflective backshort grids, and Superconducting Quantum Interference Device (SQUID) multiplexer readouts. The detector array is a filled, square grid of bolometers with superconducting sensors. The backshort arrays are fabricated separately and are positioned in the etch cavities behind the detector grid. The grids have unique three-dimensional interlocking features micromachined into the walls for positioning and mechanical stability. The ultimate goal of the program is to produce large-format arrays with background-limited sensitivity, suitable for a wide range of wavelengths and applications. Large-format (kilopixel) arrays will be directly indium bump bonded to a SQUID multiplexer circuit. We have produced and tested 8×8 arrays of 1 mm detectors to demonstrate proof of concept. 8×16 arrays of 2 mm detectors are being produced for a new Goddard Space Flight Center instrument. We have also produced models of a kilopixel detector grid and dummy multiplexer chip for bump bonding development. We present detector design overview, several unique fabrication highlights, and assembly technologies.

A method for simulating a flux-locked DC SQUID

NASA Technical Reports Server (NTRS)

Gutt, G. M.; Kasdin, N. J.; Condron, M. R., II; Muhlfelder, B.; Lockhart, J. M.; Cromar, M. W.

1993-01-01

The authors describe a computationally efficient and accurate method for simulating a dc SQUID's V-Phi (voltage-flux) and I-V characteristics which has proven valuable in evaluating and improving various SQUID readout methods. The simulation of the SQUID is based on fitting of previously acquired data from either a real or a modeled device using the Fourier transform of the V-Phi curve. This method does not predict SQUID behavior, but rather is a way of replicating a known behavior efficiently with portability into various simulation programs such as SPICE. The authors discuss the methods used to simulate the SQUID and the flux-locking control electronics, and present specific examples of this approach. Results include an estimate of the slew rate and linearity of a simple flux-locked loop using a characterized dc SQUID.

Failure Analysis of CCD Image Sensors Using SQUID and GMR Magnetic Current Imaging

NASA Technical Reports Server (NTRS)

Felt, Frederick S.

2005-01-01

During electrical testing of a Full Field CCD Image Senor, electrical shorts were detected on three of six devices. These failures occurred after the parts were soldered to the PCB. Failure analysis was performed to determine the cause and locations of these failures on the devices. After removing the fiber optic faceplate, optical inspection was performed on the CCDs to understand the design and package layout. Optical inspection revealed that the device had a light shield ringing the CCD array. This structure complicated the failure analysis. Alternate methods of analysis were considered, including liquid crystal, light and thermal emission, LT/A, TT/A SQUID, and MP. Of these, SQUID and MP techniques were pursued for further analysis. Also magnetoresistive current imaging technology is discussed and compared to SQUID.

Squids old and young: Scale-free design for a simple billboard

NASA Astrophysics Data System (ADS)

Packard, Andrew

2011-03-01

Squids employ a large range of brightness-contrast spatial frequencies in their camouflage and signalling displays. The 'billboard' of coloured elements ('spots'=chromatophore organs) in the skin is built autopoietically-probably by lateral inhibitory processes-and enlarges as much as 10,000-fold during development. The resulting two-dimensional array is a fractal-like colour/size hierarchy lying in several layers of a multilayered network. Dynamic control of the array by muscles and nerves produces patterns that recall 'half-tone' processing (cf. ink-jet printer). In the more sophisticated (loliginid) squids, patterns also combine 'continuous tones' (cf. dye-sublimation printer). Physiologists and engineers can exploit the natural colour-coding of the integument to understand nerve and muscle system dynamics, examined here at the level of the ensemble. Integrative functions of the whole (H) are analysed in terms of the power spectrum within and between ensembles and of spontaneous waves travelling through the billboard. Video material may be obtained from the author at the above address.

The Impact of Crosstalk in the X-IFU Instrument on Athena Science Cases

NASA Technical Reports Server (NTRS)

Hartog, R. Den; Peille, P.; Dauser, T.; Jackson, B.; Bandler, S.; Barret, D.; Brand, T.; Herder, J-W Den; Kiviranta, M.; Kuur, J. Van Der;

Development of transition edge sensors with rf-SQUID based multiplexing system for the HOLMES experiment

NASA Astrophysics Data System (ADS)

Puiu, A.; Becker, D.; Bennett, D.; Faverzani, M.; Ferri, E.; Fowler, J.; Gard, J.; Hays-Wehle, J.; Hilton, G.; Giachero, A.; Maino, M.; Mates, J.; Nucciotti, A.; Schmidt, D.; Swetz, D.; Ullom, J.; Vale, L.

2017-09-01

Measuring the neutrino mass is one the most compelling issue in particle physics. HOLMES is an experiment funded by the European Research Council for a direct measurement of neutrino mass. HOLMES will perform a precise measurement of the end point of the Electron Capture decay spectrum of 163Ho in order to extract information on neutrino mass with a sensitivity as low as 1 eV. HOLMES, in its final configuration will deploy a 1000 pixel array of low temperature microcalorimeters: each calorimeter consists of an absorber, where the Ho atoms will be implanted, coupled to a Transition Edge Sensor thermometer. The detectors will be kept at the working temperature of ˜70 mK using a dilution refrigerator. In order to gather the required 3 × 1013 events in a three year long data taking with a pile up fraction as low as 10-4, detectors must fulfill rather high speed and resolution requirements, i.e. 10 µs rise time and 4 eV resolution. To ensure such performances with an efficient read out technique for very large detectors array kept at low temperature inside a cryostat is no trivial matter: at the moment, the most appealing read out technique applicable to large arrays of Transition Edge Sensors is rf-SQUID multiplexing. It is based on the use of rf-SQUIDs as input devices with flux ramp modulation for linearisation purposes; the rf-SQUID is then coupled to a super-conductive λ/4-wave resonator in the GHz range, and the modulated signal is finally read out using the homodyne technique.

Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

NASA Astrophysics Data System (ADS)

Doriese, W. B.; Morgan, K. M.; Bennett, D. A.; Denison, E. V.; Fitzgerald, C. P.; Fowler, J. W.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Irwin, K. D.; Joe, Y. I.; Mates, J. A. B.; O'Neil, G. C.; Reintsema, C. D.; Robbins, N. O.; Schmidt, D. R.; Swetz, D. S.; Tatsuno, H.; Vale, L. R.; Ullom, J. N.

2016-07-01

Time-division multiplexing (TDM) is a mature scheme for the readout of arrays of transition-edge sensors (TESs). TDM is based on superconducting-quantum-interference-device (SQUID) current amplifiers. Multiple spectrometers based on gamma-ray and X-ray microcalorimeters have been operated with TDM readout, each at the scale of 200 sensors per spectrometer, as have several astronomical cameras with thousands of sub-mm or microwave bolometers. Here we present the details of two different versions of our TDM system designed to read out X-ray TESs. The first has been field-deployed in two 160-sensor (8 columns × 20 rows) spectrometers and four 240-sensor (8 columns × 30 rows) spectrometers. It has a three-SQUID-stage architecture, switches rows every 320 ns, and has total readout noise of 0.41 μ Φ 0 / surd Hz. The second, which is presently under development, has a two-SQUID-stage architecture, switches rows every 160 ns, and has total readout noise of 0.19 μ Φ 0 / surd Hz. Both quoted noise values are non-multiplexed and referred to the first-stage SQUID. In a demonstration of this new architecture, a multiplexed 1-column × 32-row array of NIST TESs achieved average energy resolution of 2.55± 0.01 eV at 6 keV.

The Micro-X Imaging X-Ray Microcalorimeter Sounding Rocket Payload: Final Design and Performance Tests

NASA Astrophysics Data System (ADS)

Rutherford, John; Micro-X Collaboration

2011-09-01

The first operating set of transition edge sensors (TES) microcalorimeters in space will launch on a sounding rocket carrying the Micro-X imaging X-ray telescope in 2012. We present the final instrument flight design, as well as the results from initial performance tests. A spectral resolution of 2 eV is targeted across the science band of 0.3-2.5 keV. The 12x12 spectrometer array contains 128 active pixels on a 600 micron pitch, consisting of Au/Bi absorbers and Mo/Au bilayer TESs with a transition temperature of 100 mK. A SQUID time-division multiplexer will read out the array at 30 kHz, which is limited by the rocket telemetry. The TESs have been engineered with a 2 ms time constant to match the multiplexer. The detector array and two SQUID stages of the TDM readout system are accommodated in a lightweight Mg enclosure, which is mounted to the 50 mK stage of an adiabatic demagnetization refrigerator. A third SQUID amplification stage is located on the 1.6 K liquid He stage of the cryostat. An on-board 55-Fe source will fluoresce a Ca target, providing 3.7 and 4.0 keV calibration lines that will not interfere with the scientifically interesting energy band.

SQUID (superconducting quantum interference device) arrays for simultaneous magnetic measurements: Calibration and source localization performance

NASA Astrophysics Data System (ADS)

Kaufman, Lloyd; Williamson, Samuel J.; Costaribeiro, P.

1988-02-01

Recently developed small arrays of SQUID-based magnetic sensors can, if appropriately placed, locate the position of a confined biomagnetic source without moving the array. The authors present a technique with a relative accuracy of about 2 percent for calibrating such sensors having detection coils with the geometry of a second-order gradiometer. The effects of calibration error and magnetic noise on the accuracy of locating an equivalent current dipole source in the human brain are investigated for 5- and 7-sensor probes and for a pair of 7-sensor probes. With a noise level of 5 percent of peak signal, uncertainties of about 20 percent in source strength and depth for a 5-sensor probe are reduced to 8 percent for a pair of 7-sensor probes, and uncertainties of about 15 mm in lateral position are reduced to 1 mm, for the configuration considered.

Dispersive Readout of a Superconducting Flux Qubit Using a Microstrip SQUID Amplifier

NASA Astrophysics Data System (ADS)

Johnson, J. E.; Hoskinson, E. M.; Macklin, C.; Siddiqi, I.; Clarke, John

2011-03-01

Dispersive techniques for the readout of superconducting qubits offer the possibility of high repetition-rate, quantum non-demolition measurement by avoiding dissipation close to the qubit. To achieve dispersive readout, we couple our three-junction aluminum flux qubit inductively to a 1-2 GHz non-linear oscillator formed by a capacitively shunted DC SQUID. The frequency of this resonator is modulated by the state of the qubit via the flux-dependent inductance of the SQUID. Readout is performed by probing the resonator in the linear (weak drive) regime with a microwave tone and monitoring the phase of the reflected signal. A microstrip SQUID amplifier (MSA) is used to increase the sensitivity of the measurement over that of a HEMT (high electron mobility transistor) amplifier. We report measurements of the performance of our amplification chain. Increased fidelity and reduced measurement backaction resulting from the implementation of the MSA will also be discussed. This work was funded in part by the U.S. Government and by BBN Technologies.

Superconducting Digital Multiplexers for Sensor Arrays

NASA Technical Reports Server (NTRS)

Kadin, Alan M.; Brock, Darren K.; Gupta, Deepnarayan

2004-01-01

Arrays of cryogenic microbolometers and other cryogenic detectors are being developed for infrared imaging. If the signal from each sensor is amplified, multiplexed, and digitized using superconducting electronics, then this data can be efficiently read out to ambient temperature with a minimum of noise and thermal load. HYPRES is developing an integrated system based on SQUID amplifiers, a high-resolution analog-to-digital converter (ADC) based on RSFQ (rapid single flux quantum) logic, and a clocked RSFQ multiplexer. The ADC and SQUIDs have already been demonstrated for other projects, so this paper will focus on new results of a digital multiplexer. Several test circuits have been fabricated using Nb Josephson technology and are about to be tested at T = 4.2 K, with a more complete prototype in preparation.

Multiplexing Readout of TES Microcalorimeters Based on Analog Baseband Feedback

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takei, Y.; Yamasaki, N.Y; Mitsuda, K.

2009-12-16

A TES microcalorimeter array is a promising spectrometer with excellent energy resolution and a moderate imaging capability. To realize a large format array in space, multiplexing the TES signals at the low tempersture stage is mandatory. We are developing frequency division multiplexing (FDM) based on baseband feedback technique. In FDM, each TES is AC-biased with a different carrier frequency. Signals from several pixels are summed and then read out by one SQUID. The maximum number of multiplexed pixels are limited by the frequency band in which the SQUID can be operated in a flux-locked loop, which is {approx}1 MHz withmore » standard flux-locked loop circuit. In the baseband feedback, the signal ({approx}10 kHz band) from the TES is once demodulated. Then a reconstructed copy of the modulated signal with an appropriate phase is fed back to the SQUID input coil to maintain an approximately constant magnetic flux. This can be implemented even for large cable delays and automatically suppresses the carrier. We developed a prototype electronics for the baseband feedback based on an analog phase sensitive detector (PSD) and a multiplier. Combined with Seiko 80-SSA SQUID amp, open-loop gain of 8 has been obtained for 10 kHz baseband signal at 5 MHz carrier frequency, with a moderate noise contribution of 27pA/{radical}(Hz) at input.« less

Requirements for Coregistration Accuracy in On-Scalp MEG.

PubMed

Zetter, Rasmus; Iivanainen, Joonas; Stenroos, Matti; Parkkonen, Lauri

2018-06-22

Recent advances in magnetic sensing has made on-scalp magnetoencephalography (MEG) possible. In particular, optically-pumped magnetometers (OPMs) have reached sensitivity levels that enable their use in MEG. In contrast to the SQUID sensors used in current MEG systems, OPMs do not require cryogenic cooling and can thus be placed within millimetres from the head, enabling the construction of sensor arrays that conform to the shape of an individual's head. To properly estimate the location of neural sources within the brain, one must accurately know the position and orientation of sensors in relation to the head. With the adaptable on-scalp MEG sensor arrays, this coregistration becomes more challenging than in current SQUID-based MEG systems that use rigid sensor arrays. Here, we used simulations to quantify how accurately one needs to know the position and orientation of sensors in an on-scalp MEG system. The effects that different types of localisation errors have on forward modelling and source estimates obtained by minimum-norm estimation, dipole fitting, and beamforming are detailed. We found that sensor position errors generally have a larger effect than orientation errors and that these errors affect the localisation accuracy of superficial sources the most. To obtain similar or higher accuracy than with current SQUID-based MEG systems, RMS sensor position and orientation errors should be [Formula: see text] and [Formula: see text], respectively.

Multiplexing of Hot-Electron Nanobolometers Using Microwave SQUIDs

NASA Technical Reports Server (NTRS)

Karasik, Boris S.; Day, Peter K.; Kawamura, Jonathan H.; Bumble, Bruce; LeDuc, Henry G.

2009-01-01

We have obtained the first data on the multiplexed operation of titanium hot-electron bolometers (HEB). Because of their low thermal conductance and small electron heat capacity nanobolometers are particularly interesting as sensors for far-infrared spectroscopy and mid- and near-IR calorimetry. However, the short time constant of these devices (approximately microseconds at 300-400 mK) makes time domain or audio-frequency domain multiplexing impractical. The Microwave SQUID (MSQUID) approach pursued in this work uses dc SQUIDs coupled to X-band microresonators which are, in turn, coupled to a transmission line. We used a 4-element array of Ti HEBs operated at 415 mK in a He3 dewar with an optical fiber access. The microwave signal exhibited 10-MHz wide resonances at individual MSQUD frequencies between 9 GHz and 10 GHz. The resonance depth is modulated by the current through the bolometer via a change of the SQUID flux state. The transmitted signal was amplified by a cryogenic amplifier and downconverted to baseband using an IQ mixer. A 1-dB per ??/2 responsivity was sufficient for keeping the system noise at the level of 2 pA/Hz1/2. This is more than an order of magnitude smaller than phonon noise in the HEB. The devices were able to detect single near- IR photons (1550 nm) with a time constant of 3.5 ?s. Follow-on work will scale the array to larger size and will address the microwave frequency signal generation and processing using a digital transceiver.

Superconducting Quantum Interference Device Array Based High Frequency Direction Finding on an Airborne Platform

DTIC Science & Technology

is performed using the MUSIC algorithm on the signals received on the non-uniform phased array, and the ESPRIT algorithm is used on the signals...received on the non-colocated vector sensor. The simulation results show that the MUSIC algorithm using 2D Bi-SQUIDs is able to differentiate two signals

Superconducting Detector Arrays for Astrophysics

NASA Technical Reports Server (NTRS)

Chervenak, James

2008-01-01

The next generation of astrophysics instruments will feature an order of magnitude more photon sensors or sensors that have an order of magnitude greater sensitivity. Since detector noise scales with temperature, a number of candidate technologies have been developed that use the intrinsic advantages of detector systems that operate below 1 Kelvin. Many of these systems employ of the superconducting phenomena that occur in metals at these temperatures to build ultrasensitive detectors and low-noise, low-power readout architectures. I will present one such system in use today to meet the needs of the astrophysics community at millimeter and x-ray wavelengths. Our group at NASA in collaboration with Princeton, NIST, Boulder and a number of other groups is building large format arrays of superconducting transition edge sensors (TES) read out with multiplexed superconducting quantum interference devices (SQUID). I will present the high sensitivity we have achieved in multiplexed x-ray sensors with the TES technology and describe the construction of a 1000-sensor TES/SQUID array for microwave measurements. With our collaboration's deployment of a kilopixel TES array for 2 mm radiation at the Atacarna Cosmology Telescope in November 2007, we have first images of the lensed Cosmic Microwave Background at fine angular scales.

Analogue Hawking radiation in a dc-SQUID array transmission line.

PubMed

Nation, P D; Blencowe, M P; Rimberg, A J; Buks, E

2009-08-21

We propose the use of a superconducting transmission line formed from an array of direct-current superconducting quantum interference devices for investigating analogue Hawking radiation. Biasing the array with a space-time varying flux modifies the propagation velocity of the transmission line, leading to an effective metric with a horizon. Being a fundamentally quantum mechanical device, this setup allows for investigations of quantum effects such as backreaction and analogue space-time fluctuations on the Hawking process.

Superconducting resonators as beam splitters for linear-optics quantum computation.

PubMed

Chirolli, Luca; Burkard, Guido; Kumar, Shwetank; Divincenzo, David P

2010-06-11

We propose and analyze a technique for producing a beam-splitting quantum gate between two modes of a ring-resonator superconducting cavity. The cavity has two integrated superconducting quantum interference devices (SQUIDs) that are modulated by applying an external magnetic field. The gate is accomplished by applying a radio frequency pulse to one of the SQUIDs at the difference of the two mode frequencies. Departures from perfect beam splitting only arise from corrections to the rotating wave approximation; an exact calculation gives a fidelity of >0.9992. Our construction completes the toolkit for linear-optics quantum computing in circuit quantum electrodynamics.

Localizing on-scalp MEG sensors using an array of magnetic dipole coils.

PubMed

Pfeiffer, Christoph; Andersen, Lau M; Lundqvist, Daniel; Hämäläinen, Matti; Schneiderman, Justin F; Oostenveld, Robert

2018-01-01

Accurate estimation of the neural activity underlying magnetoencephalography (MEG) signals requires co-registration i.e., determination of the position and orientation of the sensors with respect to the head. In modern MEG systems, an array of hundreds of low-Tc SQUID sensors is used to localize a set of small, magnetic dipole-like (head-position indicator, HPI) coils that are attached to the subject's head. With accurate prior knowledge of the positions and orientations of the sensors with respect to one another, the HPI coils can be localized with high precision, and thereby the positions of the sensors in relation to the head. With advances in magnetic field sensing technologies, e.g., high-Tc SQUIDs and optically pumped magnetometers (OPM), that require less extreme operating temperatures than low-Tc SQUID sensors, on-scalp MEG is on the horizon. To utilize the full potential of on-scalp MEG, flexible sensor arrays are preferable. Conventional co-registration is impractical for such systems as the relative positions and orientations of the sensors to each other are subject-specific and hence not known a priori. Herein, we present a method for co-registration of on-scalp MEG sensors. We propose to invert the conventional co-registration approach and localize the sensors relative to an array of HPI coils on the subject's head. We show that given accurate prior knowledge of the positions of the HPI coils with respect to one another, the sensors can be localized with high precision. We simulated our method with realistic parameters and layouts for sensor and coil arrays. Results indicate co-registration is possible with sub-millimeter accuracy, but the performance strongly depends upon a number of factors. Accurate calibration of the coils and precise determination of the positions and orientations of the coils with respect to one another are crucial. Finally, we propose methods to tackle practical challenges to further improve the method.

Localizing on-scalp MEG sensors using an array of magnetic dipole coils

PubMed Central

Andersen, Lau M.; Lundqvist, Daniel; Hämäläinen, Matti; Schneiderman, Justin F.; Oostenveld, Robert

2018-01-01

Accurate estimation of the neural activity underlying magnetoencephalography (MEG) signals requires co-registration i.e., determination of the position and orientation of the sensors with respect to the head. In modern MEG systems, an array of hundreds of low-Tc SQUID sensors is used to localize a set of small, magnetic dipole-like (head-position indicator, HPI) coils that are attached to the subject’s head. With accurate prior knowledge of the positions and orientations of the sensors with respect to one another, the HPI coils can be localized with high precision, and thereby the positions of the sensors in relation to the head. With advances in magnetic field sensing technologies, e.g., high-Tc SQUIDs and optically pumped magnetometers (OPM), that require less extreme operating temperatures than low-Tc SQUID sensors, on-scalp MEG is on the horizon. To utilize the full potential of on-scalp MEG, flexible sensor arrays are preferable. Conventional co-registration is impractical for such systems as the relative positions and orientations of the sensors to each other are subject-specific and hence not known a priori. Herein, we present a method for co-registration of on-scalp MEG sensors. We propose to invert the conventional co-registration approach and localize the sensors relative to an array of HPI coils on the subject’s head. We show that given accurate prior knowledge of the positions of the HPI coils with respect to one another, the sensors can be localized with high precision. We simulated our method with realistic parameters and layouts for sensor and coil arrays. Results indicate co-registration is possible with sub-millimeter accuracy, but the performance strongly depends upon a number of factors. Accurate calibration of the coils and precise determination of the positions and orientations of the coils with respect to one another are crucial. Finally, we propose methods to tackle practical challenges to further improve the method. PMID:29746486

Foraging ecology and movement patterns of jumbo squid (Dosidicus gigas) in the California Current System

NASA Astrophysics Data System (ADS)

Field, John C.; Elliger, Carl; Baltz, Ken; Gillespie, Graham E.; Gilly, William F.; Ruiz-Cooley, R. I.; Pearse, Devon; Stewart, Julia S.; Matsubu, William; Walker, William A.

2013-10-01

From 2002 to 2010, the jumbo squid (Dosidicus gigas) has been regularly encountered in large numbers throughout the California Current System (CCS). This species, usually found in subtropical waters, could affect coastal pelagic ecosystems and fisheries as both predator and prey. Neither the abundance of jumbo squid nor the optimal ocean conditions in which they flourish are well known. To understand better the potential impacts of this species on both commercial fisheries and on food-web structure we collected nearly 900 specimens from waters of the CCS, covering over 20° of latitude, over a range of depths and seasons. We used demographic information (size, sex, and maturity state) and analyzed stomach contents using morphological and molecular methods to best understand the foraging ecology of this species in different habitats of the CCS. Squid were found to consume a broad array of prey. Prey in offshore waters generally reflected the forage base reported in previous studies (mainly mesopelagic fishes and squids), whereas in more coastal waters (shelf, shelf break and slope habitats) squid foraged on a much broader mix that included substantial numbers of coastal pelagic fishes (Pacific herring and northern anchovy, as well as osmerids and salmonids in northern waters) and groundfish (Pacific hake, several species of rockfish and flatfish). We propose a seasonal movement pattern, based on size and maturity distributions along with qualitative patterns of presence or absence, and discuss the relevance of both the movement and distribution of jumbo squid over space and time. We find that jumbo squid are a generalist predator, which feeds primarily on small, pelagic or mesopelagic micronekton but also on larger fishes when they are available. We also conclude that interactions with and potential impacts on ecosystems likely vary over space and time, in response to both seasonal movement patterns and highly variable year-to-year abundance of the squid themselves.

Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Adams, J. A.; Bandler, S. B.; Busch, S. E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, J. P.;

Large voltage modulation in superconducting quantum interference devices with submicron-scale step-edge junctions

NASA Astrophysics Data System (ADS)

Lam, Simon K. H.

2017-09-01

A promising direction to improve the sensitivity of a SQUID is to increase its junction's normal resistance value, Rn, as the SQUID modulation voltage scales linearly with Rn. As a first step to develop highly sensitive single layer SQUID, submicron scale YBCO grain boundary step edge junctions and SQUIDs with large Rn were fabricated and studied. The step-edge junctions were reduced to submicron scale to increase their Rn values using focus ion beam, FIB and the measurement of transport properties were performed from 4.3 to 77 K. The FIB induced deposition layer proves to be effective to minimize the Ga ion contamination during the FIB milling process. The critical current-normal resistance value of submicron junction at 4.3 K was found to be 1-3 mV, comparable to the value of the same type of junction in micron scale. The submicron junction Rn value is in the range of 35-100 Ω, resulting a large SQUID modulation voltage in a wide temperature range. This performance promotes further investigation of cryogen-free, high field sensitivity SQUID applications at medium low temperature, e.g. at 40-60 K.

Assessing the utility of transcriptome data for inferring phylogenetic relationships among coleoid cephalopods.

PubMed

Lindgren, Annie R; Anderson, Frank E

2018-01-01

Historically, deep-level relationships within the molluscan class Cephalopoda (squids, cuttlefishes, octopods and their relatives) have remained elusive due in part to the considerable morphological diversity of extant taxa, a limited fossil record for species that lack a calcareous shell and difficulties in sampling open ocean taxa. Many conflicts identified by morphologists in the early 1900s remain unresolved today in spite of advances in morphological, molecular and analytical methods. In this study we assess the utility of transcriptome data for resolving cephalopod phylogeny, with special focus on the orders of Decapodiformes (open-eye squids, bobtail squids, cuttlefishes and relatives). To do so, we took new and previously published transcriptome data and used a unique cephalopod core ortholog set to generate a dataset that was subjected to an array of filtering and analytical methods to assess the impacts of: taxon sampling, ortholog number, compositional and rate heterogeneity and incongruence across loci. Analyses indicated that datasets that maximized taxonomic coverage but included fewer orthologs were less stable than datasets that sacrificed taxon sampling to increase the number of orthologs. Clades recovered irrespective of dataset, filtering or analytical method included Octopodiformes (Vampyroteuthis infernalis + octopods), Decapodiformes (squids, cuttlefishes and their relatives), and orders Oegopsida (open-eyed squids) and Myopsida (e.g., loliginid squids). Ordinal-level relationships within Decapodiformes were the most susceptible to dataset perturbation, further emphasizing the challenges associated with uncovering relationships at deep nodes in the cephalopod tree of life. Copyright © 2017 Elsevier Inc. All rights reserved.

Applications of Josephson Junction SQUIDs (Superconducting Quantum Interference Device) and Arrays.

DTIC Science & Technology

1982-11-01

Research, Cntract 7he transient respose is doinated by o NO. 00014-61-C-0615. and Wj. Figure 2 shows the time evolution of e a:d e M for owI, 0-1 and 5...connect a dc S 0UID "Shunted Josephson Tunel Junctions- if gh transmitter with another dc SQU D receiver by a Frequency, Self -Pvmd L Nise lifiers...resistive SQUID WVO incidentally to their self -puVzed Josepson perametric2 mplifier. Using a SQJID with 6 -2. ZmpHi, r-3xlO . and a in matching

Demonstration of a scalable frequency-domain readout of metallic magnetic calorimeters by means of a microwave SQUID multiplexer

NASA Astrophysics Data System (ADS)

Kempf, Sebastian; Wegner, Mathias; Fleischmann, Andreas; Gastaldo, Loredana; Herrmann, Felix; Papst, Maximilian; Richter, Daniel; Enss, Christian

2017-01-01

We report on the first demonstration of a scalable GHz frequency-domain readout of metallic magnetic calorimeters (MMCs) using a 64 pixel detector array that is read out by an integrated, on-chip microwave SQUID multiplexer. The detector array is optimized for detecting soft X-ray photons and the multiplexer is designed to provide a signal rise time τrise<400 ns and an intrinsic energy sensitivity ɛ <30 h . This results in an expected energy resolution Δ EFWHM <10 eV . We measured a signal rise time τrise as low as 90 ns and an energy resolution Δ EFWHM as low as 50 eV for 5.9 keV photons. The rise time is about an order of magnitude faster compared to other multiplexed low-temperature microcalorimeters and close to the intrinsic value set by the coupling between electron and spins. The energy resolution is degraded with respect to our design value due to a rather low intrinsic quality factor of the microwave resonators that is caused by the quality of the Josephson junction of the associated rf-SQUID as well as an elevated chip temperature as compared to the heat bath. Though the achieved energy resolution is not yet compatible with state-of-the-art single-channel MMCs, this demonstration of a scalable readout approach for MMCs in combination with the full understanding of the device performance showing ways how to improve represents an important milestone for the development of future large-scale MMC detector arrays.

Induced electric currents in the Alaska oil pipeline measured by gradient, fluxgate, and SQUID magnetometers

NASA Technical Reports Server (NTRS)

Campbell, W. H.; Zimmerman, J. E.

1979-01-01

The field gradient method for observing the electric currents in the Alaska pipeline provided consistent values for both the fluxgate and SQUID method of observation. These currents were linearly related to the regularly measured electric and magnetic field changes. Determinations of pipeline current were consistent with values obtained by a direct connection, current shunt technique at a pipeline site about 9.6 km away. The gradient method has the distinct advantage of portability and buried- pipe capability. Field gradients due to the pipe magnetization, geological features, or ionospheric source currents do not seem to contribute a measurable error to such pipe current determination. The SQUID gradiometer is inherently sensitive enough to detect very small currents in a linear conductor at 10 meters, or conversely, to detect small currents of one amphere or more at relatively great distances. It is fairly straightforward to achieve imbalance less than one part in ten thousand, and with extreme care, one part in one million or better.

Improved Readout Scheme for SQUID-Based Thermometry

NASA Technical Reports Server (NTRS)

Penanen, Konstantin

2007-01-01

An improved readout scheme has been proposed for high-resolution thermometers, (HRTs) based on the use of superconducting quantum interference devices (SQUIDs) to measure temperature- dependent magnetic susceptibilities. The proposed scheme would eliminate counting ambiguities that arise in the conventional scheme, while maintaining the superior magnetic-flux sensitivity of the conventional scheme. The proposed scheme is expected to be especially beneficial for HRT-based temperature control of multiplexed SQUIDbased bolometer sensor arrays. SQUID-based HRTs have become standard for measuring and controlling temperatures in the sub-nano-Kelvin temperature range in a broad range of low-temperature scientific and engineering applications. A typical SQUIDbased HRT that utilizes the conventional scheme includes a coil wound on a core made of a material that has temperature- dependent magnetic susceptibility in the temperature range of interest. The core and the coil are placed in a DC magnetic field provided either by a permanent magnet or as magnetic flux inside a superconducting outer wall. The aforementioned coil is connected to an input coil of a SQUID. Changes in temperature lead to changes in the susceptibility of the core and to changes in the magnetic flux detected by the SQUID. The SQUID readout instrumentation is capable of measuring magnetic-flux changes that correspond to temperature changes down to a noise limit .0.1 nK/Hz1/2. When the flux exceeds a few fundamental flux units, which typically corresponds to a temperature of .100 nK, the SQUID is reset. The temperature range can be greatly expanded if the reset events are carefully tracked and counted, either by a computer running appropriate software or by a dedicated piece of hardware.

Interannual and seasonal variability of winter-spring cohort of neon flying squid abundance in the Northwest Pacific Ocean during 1995-2011

NASA Astrophysics Data System (ADS)

Yu, Wei; Chen, Xinjun; Yi, Qian

2016-06-01

The neon flying squid, Ommastrephes bartramii, is a species of economically important cephalopod in the Northwest Pacific Ocean. Its short lifespan increases the susceptibility of the distribution and abundance to the direct impact of the environmental conditions. Based on the generalized linear model (GLM) and generalized additive model (GAM), the commercial fishery data from the Chinese squid-jigging fleets during 1995 to 2011 were used to examine the interannual and seasonal variability in the abundance of O. bartramii, and to evaluate the influences of variables on the abundance (catch per unit effort, CPUE). The results from GLM suggested that year, month, latitude, sea surface temperature (SST), mixed layer depth (MLD), and the interaction term ( SST×MLD) were significant factors. The optimal model based on GAM included all the six significant variables and could explain 42.43% of the variance in nominal CPUE. The importance of the six variables was ranked by decreasing magnitude: year, month, latitude, SST, MLD and SST×MLD. The squid was mainly distributed in the waters between 40°N and 44°N in the Northwest Pacific Ocean. The optimal ranges of SST and MLD were from 14 to 20°C and from 10 to 30 m, respectively. The squid abundance greatly fluctuated from 1995 to 2011. The CPUE was low during 1995-2002 and high during 2003-2008. Furthermore, the squid abundance was typically high in August. The interannual and seasonal variabilities in the squid abundance were associated with the variations of marine environmental conditions and the life history characteristics of squid.

Josephson Junction Arrays with Positional Disorder: Experiments and Simulations

DTIC Science & Technology

1988-02-01

8 By Martin Gerard Forrester (~) February 1988 Technical Report No i 2 u es;pis repoft cvr ubrs fechnical Information ~( Extracted : Date: This...2.10 SQUID bridge circuit 48 Fig. 3.1 Ic(T) for sample DA1B2-00 53 Fig. 3.2 R(T) forsample DA1B1-00 57 Fig. 3.3 R(T) fit to HN form, sample DA1B2-00 58...with positional disorder 71 Fig. 3.12 Critical field f,(q) vs. 1/q2 73 Fig. 3.13 (a) R(T) for Sierpinski gasket G2, measured with a SQUID 78 (b) R(T

Ordered arrays of Ni magnetic nanowires: Synthesis and investigation

NASA Astrophysics Data System (ADS)

Napolskii, K. S.; Eliseev, A. A.; Yesin, N. V.; Lukashin, A. V.; Tretyakov, Yu. D.; Grigorieva, N. A.; Grigoriev, S. V.; Eckerlebe, H.

2007-03-01

The present study is focused on the synthesis and investigation of anodic aluminum oxide (AAO) films and magnetic nanocomposites Ni/AAO obtained by Ni electrodeposition into porous matrix. AAO membranes and magnetic nanocomposites were investigated by HRSEM, EDX microanalysis, XRD, nitrogen capillary adsorption method, SQUID magnetometry, and polarized small-angle neutron scattering (SANS). The influence of synthesis conditions and form factor effect on the magnetic properties of nanowire arrays is reported.

The Detector and Readout Systems of the Micro-X High Resolution Microcalorimeter X-Ray Imaging Rocket

NASA Astrophysics Data System (ADS)

Wikus, P.; Doriese, W. B.; Eckart, M. E.; Adams, J. S.; Bandler, S. R.; Brekosky, R. P.; Chervenak, J. A.; Ewin, A. J.; Figueroa-Feliciano, E.; Finkbeiner, F. M.; Galeazzi, M.; Hilton, G.; Irwin, K. D.; Kelley, R. L.; Kilbourne, C. A.; Leman, S. W.; McCammon, D.; Porter, F. S.; Reintsema, C. D.; Rutherford, J. M.; Trowbridge, S. N.

2009-12-01

The Micro-X sounding rocket experiment will deploy an imaging transition-edge-sensor (TES) microcalorimeter spectrometer to observe astrophysical sources in the 0.2-3.0 keV band. The instrument has been designed at a systems level, and the first items of flight hardware are presently being built. In the first flight, planned for January 2011, the spectrometer will observe a recently discovered Silicon knot in the Puppis-A supernova remnant. Here we describe the design of the Micro-X science instrument, focusing on the instrument's detector and detector assembly. The current design of the 2-dimensional spectrometer array contains 128 close-packed pixels with a pitch of 600 μm. The conically approximated Wolter-1 mirror will map each of these pixels to a 0.95 arcmin region on the sky; the field of view will be 11.4 arcmin. Targeted energy resolution of the TESs is about 2 eV over the full observing band. A SQUID time-division multiplexer (TDM) will read out the array. The detector time constants will be engineered to approximately 2 ms to match the TDM, which samples each pixel at 32.6 kHz, limited only by the telemetry system of the rocket. The detector array and two SQUID stages of the TDM readout system are accommodated in a lightweight Mg enclosure, which is mounted to the 50 mK stage of an adiabatic demagnetization refrigerator. A third SQUID amplification stage is located on the 1.6 K liquid He stage of the cryostat. An on-board 55-Fe source will fluoresce a Ca target, providing 3.69 and 4.01 keV calibration lines that will not interfere with the scientifically interesting energy band.

Extended focal-plane array development for the International X-ray Observatory

NASA Astrophysics Data System (ADS)

Smith, Stephen J.; Bandler, Simon R.; Beyer, Joern; Chervenak, James A.; Drung, Dietmar; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; Scott Porter, F.; Sadleir, John E.

2009-12-01

We are developing arrays of transition-edge sensors (TES's) for the International X-ray observatory (IXO). The IXO microcalorimeter array will consist of a central 40×40 core of 300 μm pitch pixels with a resolution of 2.5 eV from 0.3-10 keV. To maximize the science return from the mission, an outer extended array is also required. This 52×52 array (2304 elements surrounding the core) of 600 μm pitch pixels increases the field-of-view from 2' to 5.4' with a resolution of 10 eV. However, significantly increasing the number of readout channels is unfavorable due to the increase in mass and power of the readout chain as well as adding complexity at the focal plane. Consequently, we are developing position-sensitive devices which maintain the same plate scale but at a reduced number of readout channels. One option is to use multiple absorber elements with different thermal conductances to a single TES. Position discrimination is achieved from differences in the pulse rise-time. Another new option is to inductively couple several TES's to a single SQUID. Position discrimination can be achieved by using different combinations of coupling polarity, inductive couplings and heat sink conductances. We present first results demonstrating <9 eV across four 500 μm pixels coupled to a single SQUID. A further possibility is to increase the number of channels to be time-division multiplexed in a single column at some expense in resolution. In this paper we discuss experimental results and trade-offs for these extended array options.

Nano Superconducting Quantum Interference device: A powerful tool for nanoscale investigations

NASA Astrophysics Data System (ADS)

Granata, Carmine; Vettoliere, Antonio

2016-02-01

The magnetic sensing at nanoscale level is a promising and interesting research topic of nanoscience. Indeed, magnetic imaging is a powerful tool for probing biological, chemical and physical systems. The study of small spin cluster, like magnetic molecules and nanoparticles, single electron, cold atom clouds, is one of the most stimulating challenges of applied and basic research of the next years. In particular, the magnetic nanoparticle investigation plays a fundamental role for the modern material science and its relative technological applications like ferrofluids, magnetic refrigeration and biomedical applications, including drug delivery, hyper-thermia cancer treatment and magnetic resonance imaging contrast-agent. Actually, one of the most ambitious goals of the high sensitivity magnetometry is the detection of elementary magnetic moment or spin. In this framework, several efforts have been devoted to the development of a high sensitivity magnetic nanosensor pushing sensing capability to the individual spin level. Among the different magnetic sensors, Superconducting QUantum Interference Devices (SQUIDs) exhibit an ultra high sensitivity and are widely employed in numerous applications. Basically, a SQUID consists of a superconducting ring (sensitive area) interrupted by two Josephson junctions. In the recent years, it has been proved that the magnetic response of nano-objects can be effectively measured by using a SQUID with a very small sensitive area (nanoSQUID). In fact, the sensor noise, expressed in terms of the elementary magnetic moment (spin or Bohr magneton), is linearly dependent on the SQUID loop side length. For this reason, SQUIDs have been progressively miniaturized in order to improve the sensitivity up to few spin per unit of bandwidth. With respect to other techniques, nanoSQUIDs offer the advantage of direct measurement of magnetization changes in small spin systems. In this review, we focus on nanoSQUIDs and its applications. In particular, we will discuss the motivations, the theoretical aspects, the fabrication techniques, the different nanoSQUIDs and the relative nanoscale applications.

Application of the double relaxation oscillation superconducting quantum interference device sensor to micro-tesla 1H nuclear magnetic resonance experiments

NASA Astrophysics Data System (ADS)

Kang, Chan Seok; Kim, Kiwoong; Lee, Seong-Joo; Hwang, Seong-min; Kim, Jin-Mok; Yu, Kwon Kyu; Kwon, Hyukchan; Lee, Sang Kil; Lee, Yong-Ho

2011-09-01

We developed an ultra-low field (ULF)-nuclear magnetic resonance (NMR) measurement system capable of working with a measurement field (Bm) of several micro-tesla and performed basic NMR studies with a double relaxation oscillation superconducting quantum interference device (DROS) instead of conventional dc-SQUIDs. DROS is a SQUID sensor utilizing a relaxation oscillation between a dc-SQUID and a relaxation circuit; the new unit consists of an inductor and a resistor, and is connected in parallel with the SQUID. DROS has a 10 times larger flux-to-voltage transfer coefficient (˜mV/ϕ0) than that of the dc-SQUID, and this large transfer coefficient enables the acquisition of the SQUID signal with a simple flux-locked-loop (FLL) circuit using room temperature pre-amplifiers. The DROS second-order gradiometer showed average field noise of 9.2 μϕ0/√Hz in a magnetically shielded room (MSR). In addition, a current limiter formed of a Josephson junction array was put in a flux-transformer of DROS to prevent excessive currents that can be generated from the high pre-polarization field (Bp). Using this system, we measured an 1H NMR signal in water under 2.8 μT Bm field and reconstructed a one-dimensional MR image from the 1H NMR signal under a gradient field BG of 4.09 nT/mm. In addition, we confirmed that the ULF-NMR system can measure the NMR signal in the presence of metal without any distortion by measuring the NMR signal of a sample wrapped with metal. Lastly, we have measured the scalar J-coupling of trimethylphosphate and were able to confirm a clear doublet NMR signal with the coupling strength J3[P,H] = 10.4 ± 0.8 Hz. Finally, because the existing ULF-NMR/MRI studies were almost all performed with dc-SQUID based systems, we constructed a dc-SQUID-based ULF-NMR system in addition to the DROS based system and compared the characteristics of the two different systems by operating the two systems under identical experimental conditions.

Use of a SQUID array to detect T-cells with magnetic nanoparticles in determining transplant rejection

NASA Astrophysics Data System (ADS)

Flynn, Edward R.; Bryant, H. C.; Bergemann, Christian; Larson, Richard S.; Lovato, Debbie; Sergatskov, Dmitri A.

2007-04-01

Acute rejection in organ transplant is signaled by the proliferation of T-cells that target and kill the donor cells requiring painful biopsies to detect rejection onset. An alternative non-invasive technique is proposed using a multi-channel superconducting quantum interference device (SQUID) magnetometer to detect T-cell lymphocytes in the transplanted organ labeled with magnetic nanoparticles conjugated to antibodies specifically attached to lymphocytic ligand receptors. After a magnetic field pulse, the T-cells produce a decaying magnetic signal with a characteristic time of the order of a second. The extreme sensitivity of this technique, 10 5 cells, can provide early warning of impending transplant rejection and monitor immune-suppressive chemotherapy.

Ferromagnetic resonance response of electron-beam patterned arrays of ferromagnetic nanoparticles

NASA Astrophysics Data System (ADS)

Jung, Sukkoo; Watkins, Byron; Feller, Jeffrey; Ketterson, John; Chandrasekhar, Venkat

2001-03-01

We report on the fabrication and the dynamic magnetic properties of periodic permalloy dot arrays. Electron-beam lithography and e-gun evaporation have been used to make the arrays with the aspect ratio of 2 (dot diameter : 40 nm, height : 80 nm) and periods of 100 - 200 nm. The magnetic properties of the arrays and their interactions have been investigated by ferromagnetic resonance (FMR), magnetic force microscopy (MFM), and SQUID magnetometry. The measured FMR data show that the position and magnitude of resonant absorption peaks strongly depend on the angle between magnetic field and the lattice structure. The results of dot arrays with various kinds of structural parameters will be presented. Supported by Army Research Office, DAAD19-99-1-0334/P001

Ventilation rates and activity levels of juvenile jumbo squid under metabolic suppression in the oxygen minimum zone.

PubMed

Trübenbach, Katja; Pegado, Maria R; Seibel, Brad A; Rosa, Rui

2013-02-01

The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O(2), 1 kPa, 10 °C) and measured metabolic rate, activity cycling patterns, swimming mode, escape jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, metabolic rate varied between 14 and 29 μmol O(2) g(-1) wet mass h(-1), depending on the level of activity. The mantle contraction frequency and strength were linearly correlated and increased significantly with activity level. Additionally, an increase in stroke volume and ventilatory volume per minute was observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rate dropped more than 75% during exposure to hypoxia. Maximum metabolic rate was not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity, indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squid also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameter (shortened diffusion pathway), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe 'deeply', with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per minute, and explains the maintenance of the squid's cycling activity under such O(2) conditions. During hypoxia, the respiratory cycles were shorter in length but increased in frequency. This was accompanied by an increase in the number of escape jets during active periods and a faster switch between swimming modes. In late hypoxia (onset ~170 ± 10 min), all the ventilatory processes were significantly reduced and followed by a lethargic state, a behavior that seems closely associated with the process of metabolic suppression and enables the squid to extend its residence time in the OMZ.

The DCU: the detector control unit of the SAFARI instrument onboard SPICA

NASA Astrophysics Data System (ADS)

Clénet, A.; Ravera, L.; Bertrand, B.; Cros, A.; Hou, R.; Jackson, B. D.; van Leeuwen, B. J.; Van Loon, D.; Parot, Y.; Pointecouteau, E.; Sournac, A.; Ta, N.

2012-09-01

The SpicA FAR infrared Instrument (SAFARI) is a European instrument for the infrared domain telescope SPICA, a JAXA space mission. The SAFARI detectors are Transistor Edge Sensors (TES) arranged in 3 matrixes. The TES front end electronic is based on Superconducting Quantum Interference Devices (SQUIDs) and it does the readout of the 3500 detectors with Frequency Division Multiplexing (FDM) type architecture. The Detector Control Unit (DCU), contributed by IRAP, manages the readout of the TES by computing and providing the AC-bias signals (1 - 3 MHz) to the TES and by computing the demodulation of the returning signals. The SQUID being highly non-linear, the DCU has also to provide a feedback signal to increase the SQUID dynamic. Because of the propagation delay in the cables and the processing time, a classic feedback will not be stable for AC-bias frequencies up to 3 MHz. The DCU uses a specific technique to compensate for those delays: the BaseBand FeedBack (BBFB). This digital data processing is done for the 3500 pixels in parallel. Thus, to keep the DCU power budget within its allocation we have to specifically optimize the architecture of the digital circuit with respect to the power consumption. In this paper we will mainly present the DCU architecture. We will particularly focus on the BBFB technique used to linearize the SQUID and on the optimization done to reduce the power consumption of the digital processing circuit.

Chromatographic Characterization and GC-MS Evaluation of the Bioactive Constituents with Antimicrobial Potential from the Pigmented Ink of Loligo duvauceli

PubMed Central

Girija, Smiline; Duraipandiyan, Veeramuthu; Kuppusamy, Pandi Suba; Gajendran, Hariprasad; Rajagopal, Raghuraman

2014-01-01

Chromatographic characterization and the GC-MS evaluation of the black pigmented ink of Loligo duvauceli in the present study have yielded an array of bioactive compounds with potent antimicrobial property. Facing an alarm of antimicrobial resistance globally, a need for elucidating antimicrobial agents from natural sources will be the need for the hour. In this view, this study is aimed at characterizing the black pigmented ink of the Indian squid L. duvauceli. The squid ink was subjected to crude solvent extraction and was fractionated by silica gel column chromatography. TLC and HPTLC profiles were recorded. Antimicrobial bioassay of the squid ink fractions was done by agar well diffusion method. The antimicrobial fraction was then characterized using GC-MS analysis. The results showed that the n-hexane extract upon column fractionation yielded a total of 8 fractions with the mobile phase of Hex/EtOAc in different gradients. TLC and HPTLC profiles showed a single spot with a retention factor of 0.76. Fraction 1 showed significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Lactobacillus acidophilus and a promising antifungal activity against Candida albicans. The antimicrobial fraction upon GC-MS analysis of bis(2-ethylhexyl) phthalate (BEHP) possesses the highest percentage of area normalisation (91%) with other few minor constituents. The study is concluded by stating that the antimicrobial efficacy of the squid ink might be due to the synergistic effects of the phthalate derivative and the other minor volatile compounds analysed in the squid ink. PMID:27437466

Chromatographic Characterization and GC-MS Evaluation of the Bioactive Constituents with Antimicrobial Potential from the Pigmented Ink of Loligo duvauceli.

PubMed

Girija, Smiline; Duraipandiyan, Veeramuthu; Kuppusamy, Pandi Suba; Gajendran, Hariprasad; Rajagopal, Raghuraman

2014-01-01

Chromatographic characterization and the GC-MS evaluation of the black pigmented ink of Loligo duvauceli in the present study have yielded an array of bioactive compounds with potent antimicrobial property. Facing an alarm of antimicrobial resistance globally, a need for elucidating antimicrobial agents from natural sources will be the need for the hour. In this view, this study is aimed at characterizing the black pigmented ink of the Indian squid L. duvauceli. The squid ink was subjected to crude solvent extraction and was fractionated by silica gel column chromatography. TLC and HPTLC profiles were recorded. Antimicrobial bioassay of the squid ink fractions was done by agar well diffusion method. The antimicrobial fraction was then characterized using GC-MS analysis. The results showed that the n-hexane extract upon column fractionation yielded a total of 8 fractions with the mobile phase of Hex/EtOAc in different gradients. TLC and HPTLC profiles showed a single spot with a retention factor of 0.76. Fraction 1 showed significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Lactobacillus acidophilus and a promising antifungal activity against Candida albicans. The antimicrobial fraction upon GC-MS analysis of bis(2-ethylhexyl) phthalate (BEHP) possesses the highest percentage of area normalisation (91%) with other few minor constituents. The study is concluded by stating that the antimicrobial efficacy of the squid ink might be due to the synergistic effects of the phthalate derivative and the other minor volatile compounds analysed in the squid ink.

Performance of an on-chip superconducting circulator for quantum microwave systems

NASA Astrophysics Data System (ADS)

Chapman, Benjamin; Rosenthal, Eric; Moores, Bradley; Kerckhoff, Joseph; Mates, J. A. B.; Hilton, G. C.; Vale, L. R.; Ullom, J. N.; LalumíEre, Kevin; Blais, Alexandre; Lehnert, K. W.

Microwave circulators enforce a single propagation direction for signals in an electrical network. Unfortunately, commercial circulators are bulky, lossy, and cannot be integrated close to superconducting circuits because they require strong ( kOe) magnetic fields produced by permanent magnets. Here we report on the performance of an on-chip, active circulator for superconducting microwave circuits, which uses no permanent magnets. Non-reciprocity is achieved by actively modulating reactive elements around 100 MHz, giving roughly a factor of 50 in the separation between signal and control frequencies, which facilitates filtering. The circulator's active components are dynamically tunable inductors constructed with arrays of dc-SQUIDs in series. Array inductance is tuned by varying the magnetic flux through the SQUIDs with fields weaker than 1 Oe. Although the instantaneous bandwidth of the device is narrow, the operation frequency is tunable between 4 and 8 GHz. This presentation will describe the device's theory of operation and compare its measured performance to design goals. This work is supported by the ARO under contract W911NF-14-1-0079 and the National Science Foundation under Grant Number 1125844.

Superconducting six-axis accelerometer

NASA Technical Reports Server (NTRS)

Paik, H. J.

1990-01-01

A new superconducting accelerometer, capable of measuring both linear and angular accelerations, is under development at the University of Maryland. A single superconducting proof mass is magnetically levitated against gravity or any other proof force. Its relative positions and orientations with respect to the platform are monitored by six superconducting inductance bridges sharing a single amplifier, called the Superconducting Quantum Interference Device (SQUID). The six degrees of freedom, the three linear acceleration components and the three angular acceleration components, of the platform are measured simultaneously. In order to improve the linearity and the dynamic range of the instrument, the demodulated outputs of the SQUID are fed back to appropriate levitation coils so that the proof mass remains at the null position for all six inductance bridges. The expected intrinsic noise of the instrument is 4 x 10(exp -12)m s(exp -2) Hz(exp -1/2) for linear acceleration and 3 x 10(exp -11) rad s(exp -2) Hz(exp -1/2) for angular acceleration in 1-g environment. In 0-g, the linear acceleration sensitivity of the superconducting accelerometer could be improved by two orders of magnitude. The design and the operating principle of a laboratory prototype of the new instrument is discussed.

Parasitic effects in superconducting quantum interference device-based radiation comb generators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bosisio, R., E-mail: riccardo.bosisio@nano.cnr.it; NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa; Giazotto, F., E-mail: giazotto@sns.it

2015-12-07

We study several parasitic effects on the implementation of a Josephson radiation comb generator based on a dc superconducting quantum interference device (SQUID) driven by an external magnetic field. This system can be used as a radiation generator similarly to what is done in optics and metrology, and allows one to generate up to several hundreds of harmonics of the driving frequency. First we take into account how the assumption of a finite loop geometrical inductance and junction capacitance in each SQUID may alter the operation of the devices. Then, we estimate the effect of imperfections in the fabrication ofmore » an array of SQUIDs, which is an unavoidable source of errors in practical situations. We show that the role of the junction capacitance is, in general, negligible, whereas the geometrical inductance has a beneficial effect on the performance of the device. The errors on the areas and junction resistance asymmetries may deteriorate the performance, but their effect can be limited to a large extent by a suitable choice of fabrication parameters.« less

High Resolution Imaging with MUSTANG-2 on the GBT

NASA Astrophysics Data System (ADS)

Stanchfield, Sara; Ade, Peter; Aguirre, James; Brevik, Justus A.; Cho, Hsiao-Mei; Datta, Rahul; Devlin, Mark; Dicker, Simon R.; Dober, Bradley; Duff, Shannon M.; Egan, Dennis; Ford, Pam; Hilton, Gene; Hubmayr, Johannes; Irwin, Kent; Knowles, Kenda; Marganian, Paul; Mason, Brian Scott; Mates, John A. B.; McMahon, Jeff; Mello, Melinda; Mroczkowski, Tony; Romero, Charles; Sievers, Jonathon; Tucker, Carole; Vale, Leila R.; Vissers, Michael; White, Steven; Whitehead, Mark; Ullom, Joel; Young, Alexander

2018-01-01

We present early science results from MUSTANG-2, a 90 GHz feedhorn-coupled, microwave SQUID-multiplexed TES bolometer array operating on the Robert C. Byrd Green Bank Telescope (GBT). The feedhorn and waveguide-probe-coupled detector technology is a mature technology, which has been used on instruments such as the South Pole Telescope, the Atacama Cosmology Telescope, and the Atacama B-mode Search telescope. The microwave SQUID multiplexer-based readout system developed for MUSTANG-2 currently reads out 66 detectors with a single coaxial cable and will eventually allow thousands of detectors to be multiplexed. This microwave SQUID multiplexer combines the proven abilities of millimeter wave TES detectors with the multiplexing capabilities of KIDs with no degradation in noise performance of the detectors. Each multiplexing device is read out using warm electronics consisting of a commercially available ROACH board, a DAC/ADC card, and an Intermediate Frequency mixer circuit. The hardware was originally developed by the Collaboration for Astronomy Signal Processing and Electronic Research (CASPER) group, whose primary goal is to develop scalable FPGA-based hardware with the flexibility to be used in a wide range of radio signal processing applications. MUSTANG-2 is the first on-sky instrument to use microwave SQUID multiplexing and is available as a shared-risk/PI instrument on the GBT. In MUSTANG-2’s first season 7 separate proposals were awarded a total of 230 hours of telescope time.

Recent advancements in the SQUID magnetospinogram system

NASA Astrophysics Data System (ADS)

Adachi, Yoshiaki; Kawai, Jun; Haruta, Yasuhiro; Miyamoto, Masakazu; Kawabata, Shigenori; Sekihara, Kensuke; Uehara, Gen

2017-06-01

In this study, a new superconducting quantum interference device (SQUID) biomagnetic measurement system known as magnetospinogram (MSG) is developed. The MSG system is used for observation of a weak magnetic field distribution induced by the neural activity of the spinal cord over the body surface. The current source reconstruction for the observed magnetic field distribution provides noninvasive functional imaging of the spinal cord, which enables medical personnel to diagnose spinal cord diseases more accurately. The MSG system is equipped with a uniquely shaped cryostat and a sensor array of vector-type SQUID gradiometers that are designed to detect the magnetic field from deep sources across a narrow observation area over the body surface of supine subjects. The latest prototype of the MSG system is already applied in clinical studies to develop a diagnosis protocol for spinal cord diseases. Advancements in hardware and software for MSG signal processing and cryogenic components aid in effectively suppressing external magnetic field noise and reducing the cost of liquid helium that act as barriers with respect to the introduction of the MSG system to hospitals. The application of the MSG system is extended to various biomagnetic applications in addition to spinal cord functional imaging given the advantages of the MSG system for investigating deep sources. The study also includes a report on the recent advancements of the SQUID MSG system including its peripheral technologies and wide-spread applications.

Development of Kilo-Pixel Arrays of Transition-Edge Sensors for X-Ray Spectroscopy

NASA Technical Reports Server (NTRS)

Adams, J. S.; Bandler, S. R.; Busch, S. E.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.;

Calcium transients recorded with arsenazo III in the presynaptic terminal of the squid giant synapse.

PubMed

Miledi, R; Parker, I

1981-05-22

Transient changes in free intracellular Ca2+ concentration were monitored in the presynaptic terminal of the giant synapse of the squid, by means of the Ca2+-sensitive dye arsenazo III. Calibration experiments showed a linear relation between the amount of Ca2+ injected by iontophoresis into the terminal, and the peak size of the arsenazo light absorbance record. A light signal could be detected on tetanic stimulation of the presynaptic axon bathed in sea water containing 45 mM Ca2+. During a 1 s tetanus the light signal rose approximately linearly, even though transmitter release declined rapidly and the light signal subsequently declined with a half-time of 2-6 s. The Ca2+ transient elicited by single nerve impulses was recorded by signal averaging, and showed a time course very much slower than the duration of transmitter release.

Local tuning of the order parameter in superconducting weak links: A zero-inductance nanodevice

NASA Astrophysics Data System (ADS)

Winik, Roni; Holzman, Itamar; Dalla Torre, Emanuele G.; Buks, Eyal; Ivry, Yachin

2018-03-01

Controlling both the amplitude and the phase of the superconducting quantum order parameter (" separators="|ψ ) in nanostructures is important for next-generation information and communication technologies. The lack of electric resistance in superconductors, which may be advantageous for some technologies, hinders convenient voltage-bias tuning and hence limits the tunability of ψ at the microscopic scale. Here, we demonstrate the local tunability of the phase and amplitude of ψ, obtained by patterning with a single lithography step a Nb nano-superconducting quantum interference device (nano-SQUID) that is biased at its nanobridges. We accompany our experimental results by a semi-classical linearized model that is valid for generic nano-SQUIDs with multiple ports and helps simplify the modelling of non-linear couplings among the Josephson junctions. Our design helped us reveal unusual electric characteristics with effective zero inductance, which is promising for nanoscale magnetic sensing and quantum technologies.

Broadband Direct Detection Submillimeter Spectrometer with Multiplexed Superconducting Transition Edge Thermometer Bolometers

NASA Technical Reports Server (NTRS)

Benford, D. J.; Ames, T. A.; Chervenak, J. A.; Moseley, S. H.; Shafer, R. A.; Staguhn, J. G.; Voellmer, G. M.; Pajot, F.; Rioux, C.; Phillips, T. G.;

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hattori, K.; Akiba, Y.; Arnold, K.

The readout of transition-edge sensor (TES) bolometers with a large multiplexing factor is key for the next generation cosmic microwave background (CMB) experiment, Polarbear-2, having 7588 TES bolometers. To enable the large arrays, we have been developing a readout system with a multiplexing factor of 40 in the frequency domain. Extending that architecture to 40 bolometers requires an increase in the bandwidth of the SQUID electronics, above 4 MHz. This paper focuses on cryogenic readout and shows how it affects cross talk and the responsivity of the TES bolometers. A series resistance, such as equivalent series resistance of capacitors formore » LC filters, leads to non-linear response of the bolometers. A wiring inductance modulates a voltage across the bolometers and causes cross talk. They should be controlled well to reduce systematic errors in CMB observations. As a result, we have been developing a cryogenic readout with a low series impedance and have tuned bolometers in the middle of their transition at a high frequency (>3 MHz).« less

Magnetic Sensitivity of AlMn TESes and Shielding Considerations for Next-Generation CMB Surveys

NASA Astrophysics Data System (ADS)

Vavagiakis, E. M.; Henderson, S. W.; Zheng, K.; Cho, H.-M.; Cothard, N. F.; Dober, B.; Duff, S. M.; Gallardo, P. A.; Hilton, G.; Hubmayr, J.; Irwin, K. D.; Koopman, B. J.; Li, D.; Nati, F.; Niemack, M. D.; Reintsema, C. D.; Simon, S.; Stevens, J. R.; Suzuki, A.; Westbrook, B.

2018-05-01

In the next decade, new ground-based cosmic microwave background (CMB) experiments such as Simons Observatory, CCAT-prime, and CMB-S4 will increase the number of detectors observing the CMB by an order of magnitude or more, dramatically improving our understanding of cosmology and astrophysics. These projects will deploy receivers with as many as hundreds of thousands of transition edge sensor (TES) bolometers coupled to superconducting quantum interference device (SQUID)-based readout systems. It is well known that superconducting devices such as TESes and SQUIDs are sensitive to magnetic fields. However, the effects of magnetic fields on TESes are not easily predicted due to the complex behavior of the superconducting transition, which motivates direct measurements of the magnetic sensitivity of these devices. We present comparative four-lead measurements of the critical temperature versus applied magnetic field of AlMn TESes varying in geometry, doping, and leg length, including Advanced ACT and POLARBEAR-2/Simons Array bolometers. MoCu ACTPol TESes are also tested and are found to be more sensitive to magnetic fields than the AlMn devices. We present an observation of weak-link-like behavior in AlMn TESes at low critical currents. We also compare measurements of magnetic sensitivity for time division multiplexing SQUIDs and frequency division multiplexing microwave (μ MUX) rf-SQUIDs. We discuss the implications of our measurements on the magnetic shielding required for future experiments that aim to map the CMB to near-fundamental limits.

BabySQUID: A mobile, high-resolution multichannel magnetoencephalography system for neonatal brain assessment

NASA Astrophysics Data System (ADS)

Okada, Yoshio; Pratt, Kevin; Atwood, Christopher; Mascarenas, Anthony; Reineman, Richard; Nurminen, Jussi; Paulson, Douglas

2006-02-01

We developed a prototype of a mobile, high-resolution, multichannel magnetoencephalography (MEG) system, called babySQUID, for assessing brain functions in newborns and infants. Unlike electroencephalography, MEG signals are not distorted by the scalp or the fontanels and sutures in the skull. Thus, brain activity can be measured and localized with MEG as if the sensors were above an exposed brain. The babySQUID is housed in a moveable cart small enough to be transported from one room to another. To assess brain functions, one places the baby on the bed of the cart and the head on its headrest with MEG sensors just below. The sensor array consists of 76 first-order axial gradiometers, each with a pickup coil diameter of 6mm and a baseline of 30mm, in a high-density array with a spacing of 12-14mm center-to-center. The pickup coils are 6±1mm below the outer surface of the headrest. The short gap provides unprecedented sensitivity since the scalp and skull are thin (as little as 3-4mm altogether) in babies. In an electromagnetically unshielded room in a hospital, the field sensitivity at 1kHz was ˜17fT/√Hz. The noise was reduced from ˜400to200fT/√Hz at 1Hz using a reference cancellation technique and further to ˜40fT/√Hz using a gradient common mode rejection technique. Although the residual environmental magnetic noise interfered with the operation of the babySQUID, the instrument functioned sufficiently well to detect spontaneous brain signals from babies with a signal to noise ratio (SNR) of as much as 7.6:1. In a magnetically shielded room, the field sensitivity was 17fT/√Hz at 20Hz and 30fT/√Hz at 1Hz without implementation of reference or gradient cancellation. The sensitivity was sufficiently high to detect spontaneous brain activity from a 7month old baby with a SNR as much as 40:1 and evoked somatosensory responses with a 50Hz bandwidth after as little as four averages. We expect that both the noise and the sensor gap can be reduced further by approximately half with a gain in SNR of about four. Thus, we conclude from the performance of the prototype that it should be feasible to improve the babySQUID to detect cortical activity in infants in real time with high spatial resolution.

A high-sensitivity magnetocardiography system with a divided gradiometer array inside a low boil-off Dewar

NASA Astrophysics Data System (ADS)

Lee, Y. H.; Yu, K. K.; Kim, J. M.; Kwon, H.; Kim, K.

2009-11-01

We fabricated a low-noise 64-channel first-order axial gradiometer system for measuring magnetocardiography (MCG) signals. The key technical features of the system are the compact structure of the gradiometer, division of the sensor array plate, direct mounting of the sensor plates into the Dewar bottom, reduced neck diameter of the liquid He Dewar, and compact readout electronics. To make the refill interval of liquid He longer, the distance between the compensation coil of the gradiometer and the input coil pads of the superconducting quantum interference device (SQUID) was reduced to 20 mm. By using direct ultrasonic bonding of Nb wires between the pickup coil wires and input coil pads, the superconductive connection structure became simple. The baseline of the first-order gradiometer is 70 mm, a little longer than for typical conventional axial gradiometers, to provide a larger signal amplitude for deep sources. The 64-channel gradiometer array consists of four blocks, and each block is fixed separately onto the bottom of the Dewar. The neck diameter of the He Dewar (192 mm) is smaller than the bottom diameter (280 mm) in which the gradiometers are distributed. The average boil-off rate of the Dewar is 3 l per day when the 64-channel system is in operation every day. Double relaxation oscillation SQUIDs (DROSs) having large flux-to-voltage transfer coefficients were used to operate SQUIDs via compact electronics. The magnetically shielded room (MSR) has a wall thickness of 80 mm, and consists of two layers of permalloy and one layer of aluminum. When the 64-channel system was installed inside the MSR, the field noise level of the system was about 3.5 fTrms Hz-1/2 at 100 Hz. MCG measurements with high signal quality were done successfully using the developed system. In addition to the parameter analysis method, we developed software for the three-dimensional imaging of the myocardial current on a realistic image of the heart based on the anatomical image of the torso.

Demonstration of Time Domain Multiplexed Readout for Magnetically Coupled Calorimeters

NASA Technical Reports Server (NTRS)

Porst, J.-P.; Adams, J. S.; Balvin, M.; Bandler, S.; Beyer, J.; Busch, S. E.; Drung, D.; Seidel, G. M.; Smith, S. J.; Stevenson, T. R.

2012-01-01

Magnetically coupled calorimeters (MCC) have extremely high potential for x-ray applications due to the inherent high energy resolution capability and being non-dissipative. Although very high energy-resolution has been demonstrated, until now there has been no demonstration of multiplexed read-out. We report on the first realization of a time domain multiplexed (TDM) read-out. While this has many similarities with TDM of transition-edge-sensors (TES), for MGGs the energy resolution is limited by the SQUID read-out noise and requires the well established scheme to be altered in order to minimize degradation due to noise aliasing effects. In cur approach, each pixel is read out by a single first stage SQUID (SQ1) that is operated in open loop. The outputs of the SQ1 s are low-pass filtered with an array of low cross-talk inductors, then fed into a single-stage SQUID TD multiplexer. The multiplexer is addressed from room temperature and read out through a single amplifier channel. We present results achieved with a new detector platform. Noise performance is presented and compared to expectations. We have demonstrated multiplexed X-ray spectroscopy at 5.9keV with delta_FWHM=10eV. In an optimized setup, we show it is possible to multiplex 32 detectors without significantly degrading the Intrinsic detector resolution.

The SOFIA/SAFIRE Far-Infrared Spectrometer: Highlighting Submillimeter Astrophysics and Technology

NASA Technical Reports Server (NTRS)

Benford, Dominic J.

2009-01-01

The Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory is an imaging spectrometer for wavelengths between 28 microns and 440 microns. Our design is a dual-band long-slit grating spectrometer, which provides broadband (approx. 4000 km/s) observations in two lines simultaneously over a field of view roughly 10" wide by 320" long. The low backgrounds in spectroscopy require very sensitive detectors with noise equivalent powers of order 10(exp -18) W/square root of Hz. We are developing a kilopixel, filled detector array for SAFIRE in a 32 x 40 format. The detector consists of a transition edge sensor (TES) bolometer array, a per-pixel broadband absorbing backshort array, and a NIST SQUID multiplexer readout array. This general type of array has been used successfully in the GISMO instrument, so we extrapolate to the sensitivity needed for airborne spectroscopy. Much of the cryogenic, electronics, and software infrastructure for SAFIRE have been developed. I provide here an overview of the progress on SAFIRE.

Fabrication and Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Chervenak, James A.; Adams, James S.; Bandler, Simon R.; Busch, Sara E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, Jan-Patrick;

First Astronomical Use of Multiplexed Transition Edge Sensor Bolometers

NASA Technical Reports Server (NTRS)

Staguhn, J. G.; Ames, T. A.; Benford, D. J.; Chervenak, J. A.; Grossman, E. N.; Irwin, K. D.; Khan, S. A.; Maffei, B.; Moseley, S. H.; Pajot, F.

2004-01-01

We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE's detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing 5 orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering Delta lambda/lambda = 1/7 at a resolution of delta lambda/lambda approx. 1/1200 can be acquired. This spectral resolution is sufficient to resolve Doppler-broadened line emission from external galaxies. FIBRE operates in the 350 m and 450 m bands. These bands cover line emission from the important star formation tracers neutral carbon (CI) and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry.

First Astronomical Use Of Multiplexed Transition Edge Bolometers

NASA Technical Reports Server (NTRS)

Benford, D. J.; Chervenak, J. A.; Grossman, E. N.; Irwin, K. D.; DeKotwara, S. A.; Maffei, B.; Moseley, S. H.; Pajot, F.; Phillips, T. G.; Reintsema, C. D.

2001-01-01

We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE's detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing five orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering delta-lamda/lamda = 1/7 at a resolution of delta-lamda/lamda = 1/1200 can be acquired. This spectral resolution is sufficient to resolve doppler broadened line emission from external galaxies. FIBRE operates in the 350 micrometer and 450 micrometer bands. These bands cover line emission from the important PDR tracers neutral carbon [CI] and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry.

Development of readout electronics for POLARBEAR-2 cosmic microwave background experiment

DOE PAGES

Hattori, K.; Akiba, Y.; Arnold, K.; ...

2016-01-06

The readout of transition-edge sensor (TES) bolometers with a large multiplexing factor is key for the next generation cosmic microwave background (CMB) experiment, Polarbear-2, having 7588 TES bolometers. To enable the large arrays, we have been developing a readout system with a multiplexing factor of 40 in the frequency domain. Extending that architecture to 40 bolometers requires an increase in the bandwidth of the SQUID electronics, above 4 MHz. This paper focuses on cryogenic readout and shows how it affects cross talk and the responsivity of the TES bolometers. A series resistance, such as equivalent series resistance of capacitors formore » LC filters, leads to non-linear response of the bolometers. A wiring inductance modulates a voltage across the bolometers and causes cross talk. They should be controlled well to reduce systematic errors in CMB observations. As a result, we have been developing a cryogenic readout with a low series impedance and have tuned bolometers in the middle of their transition at a high frequency (>3 MHz).« less

Kilopixel Pop-Up Bolometer Arrays for the Atacama Cosmology Telescope

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Wollack, E.; Henry, R.; Moseley, S. H.; Niemack, M.; Staggs, S.; Page, L.; Doriese, R.; Hilton, G. c.; Irwin, K. D.

2007-01-01

The recently deployed Atacama Cosmology Telescope (ACT) anticipates first light on its kilopixel array of close-packed transition-edge-sensor bolometers in November of 2007. The instrument will represent a full implementation of the next-generation, large format arrays for millimeter wave astronomy that use superconducting electronics and detectors. Achieving the practical construction of such an array is a significant step toward producing advanced detector arrays for future SOFIA instruments. We review the design considerations for the detector array produced for the ACT instrument. The first light imager consists of 32 separately instrumented 32-channel pop-up bolometer arrays (to create a 32x32 filled array of mm-wave sensors). Each array is instrumented with a 32-channel bias resistor array, Nyquist filter array, and time-division SQUID multiplexer. Each component needed to be produced in relatively large quantities with suitable uniformity to meet tolerances for array operation. An optical design was chosen to maximize absorption at the focal plane while mitigating reflections and stray light. The pop-up geometry (previously implemented with semiconducting detectors and readout on the SHARC II and HAWC instruments) enabled straightforward interface of the superconducting bias and readout circuit with the 2D array of superconducting bolometers. The array construction program balanced fabrication challenges with assembly challenges to deliver the instrument in a timely fashion. We present some of the results of the array build and characterization of its performance.

Array-scale performance of TES X-ray Calorimeters Suitable for Constellation-X

NASA Technical Reports Server (NTRS)

Kilbourne, C. A.; Bandler, S. R.; Brown, A. D.; Chervenak, J. A.; Eckart, M. E.; Finkbeiner, F. M.; Iyomoto, N.; Kelley, R. L.; Porter, F. S.; Smith, S. J.;

Summary Report of the Summer Conference of the DARPA-Materials Research Council Held in La Jolla, California on 6-30 July 1987

DTIC Science & Technology

1987-07-01

that any array detector have very broad dynamic range. iv.) Analytical methods used in extracting structural data from experimental observations from...important influence on magnet design and on specialized magnetic devices ( SQUID devices) and forms the basis for promising electronic devices ’Josephson...printable inks using 123 powders. (2) Control of interfacial reactions between the superconductors and the dielectric. (3) Development of suitable

Project SQUID. A Program of Fundamental Research on Liquid Rocket and Pulse Jet Propulsion

DTIC Science & Technology

1947-01-01

However, while the acoustical case can very well be represented by a correspond- ing linear electrical system, no way lias been found to represent...a carbon tube containing the gas to be decomposed thermally will be heated and its tem- perature determined by an optical pyrometer ; by the ojier

A study of ferromagnetic signals in SrTiO{sub 3} nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovacs, P.; Des Roches, B.; Crandles, D. A.

It has been suggested that ferromagnetism may be a universal feature of nanoparticles related to particle size. We study this claim for the case of commercially produced SrTiO{sub 3} nanoparticles purchased from Alfa-Aesar. Both loosely-packed nanoparticle samples and pellets formed using uniaxial pressure were studied. Both loose and pressed samples were annealed in either air or in vacuum of 5×10{sup −6} Torr at 600, 800 and 1000°C. Then x-ray diffraction and SQUID measurements were made on the resulting samples. It was found that annealed loose powder samples always had a linear diamagnetic magnetization versus field response, while their pressed pelletmore » counterparts exhibit a ferromagnetic hysteresis component in addition to the linear diamagnetic signal. Williamson-Hall analysis reveals that the particle size in pressed pellet samples increases with annealing temperature but does not change significantly in loose powder samples. The main conclusion is that the act of pressing pellets in a die introduces a spurious ferromagnetic signal into SQUID measurements.« less

The First Multichroic Polarimeter Array on the Atacama Cosmology Telescope: Characterization and Performance

NASA Technical Reports Server (NTRS)

Ho, S. P.; Pappas, C. G.; Austermann, J.; Beall, J. A.; Becker, D.; Choi, S. K.; Datta, R.; Duff, S. M.; Gallardo, P. A.; Grace, E.;

The First Multichroic Polarimeter Array on the Atacama Cosmology Telescope: Characterization and Performance

NASA Astrophysics Data System (ADS)

Ho, S. P.; Pappas, C. G.; Austermann, J.; Beall, J. A.; Becker, D.; Choi, S. K.; Datta, R.; Duff, S. M.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Henderson, S. W.; Hilton, G. C.; Hubmayr, J.; Koopman, B. J.; Lanen, J. V.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Niraula, P.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Ward, J. T.; Wollack, E. J.; Vavagiakis, E. M.

2016-08-01

The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive receiver for the 6-m Atacama Cosmology Telescope (ACT) and measures the small angular scale polarization anisotropies in the cosmic microwave background (CMB). The full focal plane is composed of three detector arrays, containing over 3000 transition edge sensors (TES detectors) in total. The first two detector arrays, observing at 146 GHz, were deployed in 2013 and 2014, respectively. The third and final array is composed of multichroic pixels sensitive to both 90 and 146 GHz and saw first light in February 2015. Fabricated at NIST, this dichroic array consists of 255 pixels, with a total of 1020 polarization sensitive bolometers and is coupled to the telescope with a monolithic array of broad-band silicon feedhorns. The detectors are read out using time-division SQUID multiplexing and cooled by a dilution refrigerator at 110 mK. We present an overview of the assembly and characterization of this multichroic array in the lab, and the initial detector performance in Chile. The detector array has a TES detector electrical yield of 85 %, a total array sensitivity of less than 10 \\upmu K√{ {s}}, and detector time constants and saturation powers suitable for ACT CMB observations.

Asymmetric nanowire SQUID: Linear current-phase relation, stochastic switching, and symmetries

NASA Astrophysics Data System (ADS)

Murphy, A.; Bezryadin, A.

2017-09-01

We study nanostructures based on two ultrathin superconducting nanowires connected in parallel to form a superconducting quantum interference device (SQUID). The measured function of the critical current versus magnetic field, IC(B ) , is multivalued, asymmetric, and its maxima and minima are shifted from the usual integer and half integer flux quantum points. We also propose a low-temperature-limit model which generates accurate fits to the IC(B ) functions and provides verifiable predictions. The key assumption of our model is that each wire is characterized by a sample-specific critical phase ϕC defined as the phase difference at which the supercurrent in the wire is the maximum. For our nanowires ϕC is much greater than the usual π /2 , which makes a qualitative difference in the behavior of the SQUID. The nanowire current-phase relation is assumed linear, since the wires are much longer than the coherence length. The model explains single-valuedness regions where only one vorticity value nv is stable. Also, it predicts regions where multiple vorticity values are stable because the Little-Parks (LP) diamonds, which describe the region of stability for each winding number nv in the current-field diagram, can overlap. We also observe and explain regions in which the standard deviation of the switching current is independent of the magnetic field. We develop a technique that allows a reliable detection of hidden phase slips and use it to determine the boundaries of the LP diamonds even at low currents where IC(B ) is not directly measurable.

Characterization System of Multi-pixel Array TES Microcalorimeter

NASA Astrophysics Data System (ADS)

Yoshimoto, Shota; Maehata, Keisuke; Mitsuda, Kazuhisa; Yamanaka, Yoshihiro; Sakai, Kazuhiro; Nagayoshi, Kenichiro; Yamamoto, Ryo; Hayashi, Tasuku; Muramatsu, Haruka

We have constructed characterization system for 64-pixel array transition-edge sensor (TES) microcalorimeter using a 3He-4He dilution refrigerator (DR) with the cooling power of 60 µW at a temperature of 100 mK. A stick equipped with 384 of Manganin wires was inserted into the refrigerator to perform characteristic measurements of 64-pixel array TES microcalorimeter and superconducting quantum interference device (SQUID) array amplifiers. The stick and Manganin wires were thermally anchored at temperatures of 4 and 1 K with sufficient thermal contact. The cold end of the Manganin wires were thermally anchored and connected to CuNi clad NbTi wires at 0.7 K anchor. Then CuNi clad NbTi wires were wired to connectors placed on the holder mounted on the cold stage attached to the base plate of the mixing chamber. The heat flow to the cold stage through the installed wires was estimated to be 0.15 µW. In the operation test the characterization system maintained temperature below 100 mK.

Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

NASA Astrophysics Data System (ADS)

Prele, D.

2015-08-01

As we have seen for digital camera market and a sensor resolution increasing to "megapixels", all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, "simple" and "efficient" techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described.

Atomic magnetometer for human magnetoencephalograpy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwindt, Peter; Johnson, Cort N.

2010-12-01

We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, themore » evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography.« less

The Focal Plane Assembly for the Athena X-Ray Integral Field Unit Instrument

NASA Technical Reports Server (NTRS)

Jackson, B. D.; Van Weers, H.; van der Kuur, J.; den Hartog, R.; Akamatsu, H.; Argan, A.; Bandler, S. R.; Barbera, M.; Barret, D.; Bruijn, M. P.;

Assessing the trophic position and ecological role of squids in marine ecosystems by means of food-web models

NASA Astrophysics Data System (ADS)

Coll, Marta; Navarro, Joan; Olson, Robert J.; Christensen, Villy

2013-10-01

We synthesized available information from ecological models at local and regional scales to obtain a global picture of the trophic position and ecological role of squids in marine ecosystems. First, static food-web models were used to analyze basic ecological parameters and indicators of squids: biomass, production, consumption, trophic level, omnivory index, predation mortality diet, and the ecological role. In addition, we developed various dynamic temporal simulations using two food-web models that included squids in their parameterization, and we investigated potential impacts of fishing pressure and environmental conditions for squid populations and, consequently, for marine food webs. Our results showed that squids occupy a large range of trophic levels in marine food webs and show a large trophic width, reflecting the versatility in their feeding behaviors and dietary habits. Models illustrated that squids are abundant organisms in marine ecosystems, and have high growth and consumption rates, but these parameters are highly variable because squids are adapted to a large variety of environmental conditions. Results also show that squids can have a large trophic impact on other elements of the food web, and top-down control from squids to their prey can be high. In addition, some squid species are important prey of apical predators and may be keystone species in marine food webs. In fact, we found strong interrelationships between neritic squids and the populations of their prey and predators in coastal and shelf areas, while the role of squids in open ocean and upwelling ecosystems appeared more constrained to a bottom-up impact on their predators. Therefore, large removals of squids will likely have large-scale effects on marine ecosystems. In addition, simulations confirm that squids are able to benefit from a general increase in fishing pressure, mainly due to predation release, and quickly respond to changes triggered by the environment. Squids may thus be very sensitive to the effects of fishing and climate change.

Postmortem biochemical behavior of giant squid (Dosidicus gigas) mantle muscle stored in ice and its relation with quality parameters.

PubMed

Márquez-Ríos, E; Morán-Palacio, E F; Lugo-Sánchez, M E; Ocano-Higuera, V M; Pacheco-Aguilar, R

2007-09-01

Several freshness and spoilage indicators were monitored to characterize the postmortem biochemistry of giant squid (Dosidicus gigas) mantle muscle. Squid samples were obtained directly from the sea and kept at 0 degrees C during a 15-d storage period. Data at zero time were obtained from cryogenically frozen samples at time of capture. The adenosine 5'-triphosphate (ATP) degradation followed a different pattern as compared with that from fish species. ATP was almost completely depleted at 24-h postcatch from 6.54 to <1 micromol/g, while at the same time Hx was the predominant catabolite with a concentration of 4 mumol/g, reaching 6.85 micromol/g at day 15. K-value data followed a logarithmic pattern with time instead of a linear one, with no change after day 3, thus reducing its suitability as a freshness index. The coefficient Hx/AMP seems to be an adequate alternative for this purpose due to its constant increment with time. The high NH4Cl content in mantle muscle (461.3 +/- 24.5 mg of NH4(+)/100 g) derived from its physiological importance for the species compromises the use of the distillation step of the TVB-N analysis commonly used as a spoilage index. This fact explains why the initially high value of TVB-N detected in mantle muscle (243.7 mg N/100 g) did not correlate with the initial low TMA-N content (1.5 +/- 0.1 mg/100 g of muscle). The results suggested that under the experimental conditions the shelf life of squid exceeds 15 d.

Resolution of fine biological structure including small narcomedusae across a front in the Southern California Bight

NASA Astrophysics Data System (ADS)

McClatchie, Sam; Cowen, Robert; Nieto, Karen; Greer, Adam; Luo, Jessica Y.; Guigand, Cedric; Demer, David; Griffith, David; Rudnick, Daniel

2012-04-01

We sampled a front detected by SST gradient, ocean color imagery, and a Spray glider south of San Nicolas Island in the Southern California Bight between 14 and 18 October 2010. We sampled the front with an unusually extensive array of instrumentation, including the Continuous Underway Fish Egg Sampler (CUFES), the undulating In Situ Ichthyoplankton Imaging System (ISIIS) (fitted with temperature, salinity, oxygen, and fluorescence sensors), multifrequency acoustics, a surface pelagic trawl, a bongo net, and a neuston net. We found higher fluorescence and greater cladoceran, decapod, and euphausiid densities in the front, indicating increased primary and secondary production. Mesopelagic fish were most abundant in oceanic waters to the west of the front, market squid were abundant in the front associated with higher krill and decapod densities, and jack mackerel were most common in the front and on the shoreward side of the front. Egg densities peaked to either side of the front, consistent with both offshore (for oceanic squid and mesopelagic fish) and shelf origins (for white croaker and California halibut). We discovered unusually high concentrations of predatory narcomedusae in the surface layer of the frontal zone. Potential ichthyoplankton predators were more abundant either in the front (decapods, euphausiids, and squid) or shoreward of the front (medusae, chaetognaths, and jack mackerel). For pelagic fish like sardine, which can thrive in less productive waters, the safest place to spawn would be offshore because there are fewer potential predators.

Effects of the dipolar form of phloretin on potassium conductance in squid giant axons.

PubMed Central

Strichartz, G R; Oxford, G S; Ramon, F

1980-01-01

The effects of phloretin on membrane ionic conductances have been studied in the giant axon of the squid, Loligo pealei. Phloretin reversibly suppresses the potassium and sodium conductances and modifies their dependence on membrane potential (Em). Its effects on the potassium conductance (GK) are much greater than on the sodium conductance; no effects on sodium inactivation are observed. Internal perfusion of phloretin produces both greater shifts in GK(Em) and greater reductions maximum GK than does external perfusion; the effect of simultaneous internal and external perfusion is little greater than that of internal perfusion alone. Lowering the internal pH, which favors the presence of the neutral species of weakly acidic phloretin (pKa 7.4), potentiates the actions of internally perfused phloretin. Other organic cations with dipole moments similar to phloretin's have little effect on either potassium or sodium conductances in squid axons. These results can be explained by either of two mechanisms; on postulates a phloretin "receptor" near the voltage sensor component of the potassium channel which is accessible to drug molecules applied at either the outer or inner membrane surface and is much more sensitive to the neutral than the negatively charged form of the drug. The other mechanism proposes that neutral phloretin molecules are dispersed in an ordered array in the membrane interior, producing a diffuse dipole field which modifies potassium channel gating. Different experimental results support these two mechanisms, and neither hypothesis can be disproven. PMID:6266534

Mollusk genes encoding lysine tRNA (UUU) contain introns.

PubMed

Matsuo, M; Abe, Y; Saruta, Y; Okada, N

1995-11-20

New intron-containing genes encoding tRNAs were discovered when genomic DNA isolated from various animal species was amplified by the polymerase chain reaction (PCR) with primers based on sequences of rabbit tRNA(Lys). From sequencing analysis of the products of PCR, we found that introns are present in several genes encoding tRNA(Lys) in mollusks, such as Loligo bleekeri (squid) and Octopus vulgaris (octopus). These introns were specific to genes encoding tRNA(Lys)(CUU) and were not present in genes encoding tRNA(Lys)(CUU). In addition, the sequences of the introns were different from one another. To confirm the results of our initial experiments, we isolated and sequenced genes encoding tRNA(Lys)(CUU) and tRNA(Lys)(UUU). The gene for tRNA(Lys)(UUU) from squid contained an intron, whose sequence was the same as that identified by PCR, and the gene formed a cluster with a corresponding pseudogene. Several DNA regions of 2.1 kb containing this cluster appeared to be tandemly arrayed in the squid genome. By contrast, the gene encoding tRNA(Lys)(CUU) did not contain an intron, as shown also by PCR. The tRNA(Lys)(UUU) that corresponded to the analyzed gene was isolated and characterized. The present study provides the first example of an intron-containing gene encoding a tRNA in mollusks and suggests the universality of introns in such genes in higher eukaryotes.

5,120 Superconducting Bolometers for the PIPER Balloon-Borne CMB Polarization Experiment

NASA Technical Reports Server (NTRS)

Benford, Dominic J.; Chuss, David T.; Hilton, Gene C.; Irwin, Kent D.; Jethava, Nikhil S.; Jhabvala, Christine A.; Kogut, Alan J.; Miller, Timothy M.; Mirel, Paul; Moseley, S. Harvey;

Low noise SQUIDs

NASA Astrophysics Data System (ADS)

de Waal, V. J.

1983-02-01

The present investigation deals with the design, fabrication, and limitations of very sensitive SQUID (Superconducting Quantum Interference Device) magnetometers. The SQUID magnetometer is based on a utilization of the Josephson effect. A description of the theoretical background is provided, and high performance DC SQUIDs with submicron niobium Josephson junctions are discussed, taking into account design considerations, fabrication, junction characterization, the performance of the SQUID and input coil, and the gradiometer performance. The simulation and optimization of a DC SQUID with finite capacitance is considered, giving attention to the implementation of a simulation procedure on a hybrid computer.

Lowering effect of firefly squid powder on triacylglycerol content and glucose-6-phosphate dehydrogenase activity in rat liver.

PubMed

Takeuchi, Hiroyuki; Morita, Ritsuko; Shirai, Yoko; Nakagawa, Yoshihisa; Terashima, Teruya; Ushikubo, Shun; Matsuo, Tatsuhiro

2014-01-01

Effects of dietary firefly squid on serum and liver lipid levels were investigated. Male Wistar rats were fed a diet containing 5% freeze-dried firefly squid or Japanese flying squid for 2 weeks. There was no significant difference in the liver triacylglycerol level between the control and Japanese flying squid groups, but the rats fed the firefly squid diet had a significantly lower liver triacylglycerol content than those fed the control diet. No significant difference was observed in serum triacylglycerol levels between the control and firefly squid groups. The rats fed the firefly squid had a significantly lower activity of liver glucose-6-phosphate dehydrogenase compared to the rats fed the control diet. There was no significant difference in liver fatty acid synthetase activity among the three groups. Hepatic gene expression and lipogenic enzyme activity were investigated; a DNA microarray showed that the significantly enriched gene ontology category of down-regulated genes in the firefly squid group was "lipid metabolic process". The firefly squid group had lower mRNA level of glucose-6-phosphate dehydrogenase compared to the controls. These results suggest that an intake of firefly squid decreases hepatic triacylglycerol in rats, and the reduction of mRNA level and enzyme activity of glucose-6-phosphate dehydrogenase might be related to the mechanisms.

Characterization of Kilopixel TES detector arrays for PIPER

NASA Astrophysics Data System (ADS)

Datta, Rahul; Ade, Peter; Benford, Dominic; Bennett, Charles; Chuss, David; Costen, Nicholas; Coughlin, Kevin; Dotson, Jessie; Eimer, Joseph; Fixsen, Dale; Gandilo, Natalie; Halpern, Mark; Essinger-Hileman, Thomas; Hilton, Gene; Hinshaw, Gary; Irwin, Kent; Jhabvala, Christine; Kimball, Mark; Kogut, Al; Lazear, Justin; Lowe, Luke; Manos, George; McMahon, Jeff; Miller, Timothy; Mirel, Paul; Moseley, Samuel Harvey; Pawlyk, Samuel; Rodriguez, Samelys; Sharp, Elmer; Shirron, Peter; Staguhn, Johannes G.; Sullivan, Dan; Switzer, Eric; Taraschi, Peter; Tucker, Carole; Walts, Alexander; Wollack, Edward

2018-01-01

The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne instrument optimized to measure the polarization of the Cosmic Microwave Background (CMB) at large angular scales. It will map 85% of the sky in four frequency bands centered at 200, 270, 350, and 600 GHz to characterize dust foregrounds and constrain the tensor-to-scalar ratio, r. The sky is imaged on to 32x40 pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers operating at a bath temperature of 100 mK to achieve background-limited sensitivity. Each kilopixel array is indium-bump-bonded to a 2D superconducting quantum interference device (SQUID) time-domain multiplexer (MUX) chip and read out by warm electronics. Each pixel measures total incident power over a frequency band defined by bandpass filters in front of the array, while polarization sensitivity is provided by the upstream Variable-delay Polarization Modulators (VPMs) and analyzer grids. We present measurements of the detector parameters from the laboratory characterization of the first kilopixel science array for PIPER including transition temperature, saturation power, thermal conductivity, time constant, and noise performance. We also describe the testing of the 2D MUX chips, optimization of the integrated readout parameters, and the overall pixel yield of the array. The first PIPER science flight is planned for June 2018 from Palestine, Texas.

Distributed Antenna-Coupled TES for FIR Detectors Arrays

NASA Technical Reports Server (NTRS)

Day, Peter K.; Leduc, Henry G.; Dowell, C. Darren; Lee, Richard A.; Zmuidzinas, Jonas

2007-01-01

We describe a new architecture for a superconducting detector for the submillimeter and far-infrared. This detector uses a distributed hot-electron transition edge sensor (TES) to collect the power from a focal-plane-filling slot antenna array. The sensors lay directly across the slots of the antenna and match the antenna impedance of about 30 ohms. Each pixel contains many sensors that are wired in parallel as a single distributed TES, which results in a low impedance that readily matches to a multiplexed SQUID readout These detectors are inherently polarization sensitive, with very low cross-polarization response, but can also be configured to sum both polarizations. The dual-polarization design can have a bandwidth of 50The use of electron-phonon decoupling eliminates the need for micro-machining, making the focal plane much easier to fabricate than with absorber-coupled, mechanically isolated pixels. We discuss applications of these detectors and a hybridization scheme compatible with arrays of tens of thousands of pixels.

SQUID magnetometers for low-frequency applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryhaenen, T.; Seppae, H.; Ilmoniemi, R.

1989-09-01

The authors present a novel formulation for SQUID operation, which enables them to evaluate and compare the sensitivity and applicability of different devices. SQUID magnetometers for low-frequency applications are analyzed, taking into account the coupling circuits and electronics. They discuss nonhysteretic and hysteretic single-junction rf SQUIDs, but the main emphasis is on the dynamics, sensitivity, and coupling considerations of dc-SQUID magnetometers. A short review of current ideas on thin-film, dc-SQUID design presents the problems in coupling and the basic limits of sensitivity. The fabrication technology of tunnel-junction devices is discussed with emphasis on how it limits critical current densities, specificmore » capacitances of junctions, minimum linewidths, conductor separations, etc. Properties of high-temperature superconductors are evaluated on the basis of recently published results on increased flux creep, low density of current carriers, and problems in fabricating reliable junctions. The optimization of electronics for different types of SQUIDs is presented. Finally, the most important low-frequency applications of SQUIDs in biomagnetism, metrology, geomagnetism, and some physics experiments demonstrate the various possibilities that state-of-the-art SQUIDs can provide.« less

Flux trapping in multi-loop SQUIDs and its impact on SQUID-based absolute magnetometry

NASA Astrophysics Data System (ADS)

Schönau, T.; Zakosarenko, V.; Schmelz, M.; Anders, S.; Meyer, H.-G.; Stolz, R.

2018-07-01

The effect of flux trapping on the flux-voltage characteristics of multi-loop SQUID magnetometers was investigated by means of repeated cool-down cycles in a stepwise increased magnetic background field. For a SQUID with N parallel loops, N different flux offsets, each separated by {{{Φ }}}0/N, were observed even in zero magnetic field. These flux offsets further split into a so called fine structure, which can be explained by minor asymmetries in the SQUID design. The observed results are discussed with particular regard to their impact on the previously presented absolute SQUID cascade vector magnetometer.

Controlled and in situ target strengths of the jumbo squid Dosidicus gigas and identification of potential acoustic scattering sources.

PubMed

Benoit-Bird, Kelly J; Gilly, William F; Au, Whitlow W L; Mate, Bruce

2008-03-01

This study presents the first target strength measurements of Dosidicus gigas, a large squid that is a key predator, a significant prey, and the target of an important fishery. Target strength of live, tethered squid was related to mantle length with values standardized to the length squared of -62.0, -67.4, -67.9, and -67.6 dB at 38, 70, 120, and 200 kHz, respectively. There were relatively small differences in target strength between dorsal and anterior aspects and none between live and freshly dead squid. Potential scattering mechanisms in squid have been long debated. Here, the reproductive organs had little effect on squid target strength. These data support the hypothesis that the pen may be an important source of squid acoustic scattering. The beak, eyes, and arms, probably via the sucker rings, also play a role in acoustic scattering though their effects were small and frequency specific. An unexpected source of scattering was the cranium of the squid which provided a target strength nearly as high as that of the entire squid though the mechanism remains unclear. Our in situ measurements of the target strength of free-swimming squid support the use of the values presented here in D. gigas assessment studies.

Effects of thermal processing and various chemical substances on formaldehyde and dimethylamine formation in squid Dosidicus gigas.

PubMed

Zhu, Junli; Li, Jianrong; Jia, Jia

2012-09-01

Trimethylamine oxide (TMAO) in squid is demethylated to dimethylamine (DMA) and formaldehyde (FA) during storage and processing. This study examined the effects of thermal processing and various chemical substances on FA and DMA formation in squid. The thermal conversion of TMAO was assessed by analysing four squid and four gadoid fish species, which revealed that FA, DMA and trimethylamine (TMA) were gradually produced in squid, whereas TMA increased and FA decreased in gadoid fish. A significant increase in both FA and DMA levels was observed in the supernatant of jumbo squid with increased heating temperature and extended heating time at pH 6-7. Ferrous chloride combined with cysteine and/or ascorbate had a significantly positive effect on FA formation in the heated supernatant of jumbo squid. No significant difference was observed in the levels of Cu and Fe in squid and gadoid fish. The capability of Fe(2+) to promote the formation of FA and DMA was not completely attributable to its reducing power in squid. Non-enzymatic decomposition of TMAO was a key pathway during the thermal processing of jumbo squid, and Fe(2+) was a crucial activator in the formation of FA and DMA. Copyright © 2012 Society of Chemical Industry.

Scanning SQUID Microscope and its Application in Detecting Weak Currents

NASA Astrophysics Data System (ADS)

Zhong, Chaorong; Li, Fei; Zhang, Fenghui; Ding, Hongsheng; Luo, Sheng; Lin, Dehua; He, Yusheng

A scanning SQUID microscope based on HTS dc SQUID has been developed. One of the applications of this microscope is to detect weak currents inside the sample. Considering that what being detected by the SQUID is the vertical component of the magnetic field on a plan where the SQUID lies, whereas the current which produces the magnetic field is actually located in a plan below the SQUID, a TWO PLAN model has been established. In this model Biot-Savart force laws and Fourier transformation were used to inverse the detected magnetic field into the underneath weak current. It has been shown that the distance between the current and the SQUID and the noise ratio of the experimental data have significant effects on the quality of the inverse process.

Identifying Pelagic Habitat Hotspots of Neon Flying Squid in the Temperate Waters of the Central North Pacific.

PubMed

Alabia, Irene D; Saitoh, Sei-Ichi; Mugo, Robinson; Igarashi, Hiromichi; Ishikawa, Yoichi; Usui, Norihisa; Kamachi, Masafumi; Awaji, Toshiyuki; Seito, Masaki

2015-01-01

We identified the pelagic habitat hotspots of the neon flying squid (Ommastrephes bartramii) in the central North Pacific from May to July and characterized the spatial patterns of squid aggregations in relation to oceanographic features such as mesoscale oceanic eddies and the Transition Zone Chlorophyll-a Front (TZCF). The data used for the habitat model construction and analyses were squid fishery information, remotely-sensed and numerical model-derived environmental data from May to July 1999-2010. Squid habitat hotspots were deduced from the monthly Maximum Entropy (MaxEnt) models and were identified as regions of persistent high suitable habitat across the 12-year period. The distribution of predicted squid habitat hotspots in central North Pacific revealed interesting spatial and temporal patterns likely linked with the presence and dynamics of oceanographic features in squid's putative foraging grounds from late spring to summer. From May to June, the inferred patches of squid habitat hotspots developed within the Kuroshio-Oyashio transition zone (KOTZ; 37-40°N) and further expanded north towards the subarctic frontal zone (SAFZ; 40-44°N) in July. The squid habitat hotspots within the KOTZ and areas west of the dateline (160°W-180°) were likely influenced and associated with the highly dynamic and transient oceanic eddies and could possibly account for lower squid suitable habitat persistence obtained from these regions. However, predicted squid habitat hotspots located in regions east of the dateline (180°-160°W) from June to July, showed predominantly higher squid habitat persistence presumably due to their proximity to the mean position of the seasonally-shifting TZCF and consequent utilization of the highly productive waters of the SAFZ.

BabyMEG: A whole-head pediatric magnetoencephalography system for human brain development research

NASA Astrophysics Data System (ADS)

Okada, Yoshio; Hämäläinen, Matti; Pratt, Kevin; Mascarenas, Anthony; Miller, Paul; Han, Menglai; Robles, Jose; Cavallini, Anders; Power, Bill; Sieng, Kosal; Sun, Limin; Lew, Seok; Doshi, Chiran; Ahtam, Banu; Dinh, Christoph; Esch, Lorenz; Grant, Ellen; Nummenmaa, Aapo; Paulson, Douglas

2016-09-01

We developed a 375-channel, whole-head magnetoencephalography (MEG) system ("BabyMEG") for studying the electrophysiological development of human brain during the first years of life. The helmet accommodates heads up to 95% of 36-month old boys in the USA. The unique two-layer sensor array consists of: (1) 270 magnetometers (10 mm diameter, ˜15 mm coil-to-coil spacing) in the inner layer, (2) thirty-five three-axis magnetometers (20 mm × 20 mm) in the outer layer 4 cm away from the inner layer. Additionally, there are three three-axis reference magnetometers. With the help of a remotely operated position adjustment mechanism, the sensor array can be positioned to provide a uniform short spacing (mean 8.5 mm) between the sensor array and room temperature surface of the dewar. The sensors are connected to superconducting quantum interference devices (SQUIDs) operating at 4.2 K with median sensitivity levels of 7.5 fT/√Hz for the inner and 4 fT/√Hz for the outer layer sensors. SQUID outputs are digitized by a 24-bit acquisition system. A closed-cycle helium recycler provides maintenance-free continuous operation, eliminating the need for helium, with no interruption needed during MEG measurements. BabyMEG with the recycler has been fully operational from March, 2015. Ongoing spontaneous brain activity can be monitored in real time without interference from external magnetic noise sources including the recycler, using a combination of a lightly shielded two-layer magnetically shielded room, an external active shielding, a signal-space projection method, and a synthetic gradiometer approach. Evoked responses in the cortex can be clearly detected without averaging. These new design features and capabilities represent several advances in MEG, increasing the utility of this technique in basic neuroscience as well as in clinical research and patient studies.

BabyMEG: A whole-head pediatric magnetoencephalography system for human brain development research.

PubMed

Okada, Yoshio; Hämäläinen, Matti; Pratt, Kevin; Mascarenas, Anthony; Miller, Paul; Han, Menglai; Robles, Jose; Cavallini, Anders; Power, Bill; Sieng, Kosal; Sun, Limin; Lew, Seok; Doshi, Chiran; Ahtam, Banu; Dinh, Christoph; Esch, Lorenz; Grant, Ellen; Nummenmaa, Aapo; Paulson, Douglas

2016-09-01

We developed a 375-channel, whole-head magnetoencephalography (MEG) system ("BabyMEG") for studying the electrophysiological development of human brain during the first years of life. The helmet accommodates heads up to 95% of 36-month old boys in the USA. The unique two-layer sensor array consists of: (1) 270 magnetometers (10 mm diameter, ∼15 mm coil-to-coil spacing) in the inner layer, (2) thirty-five three-axis magnetometers (20 mm × 20 mm) in the outer layer 4 cm away from the inner layer. Additionally, there are three three-axis reference magnetometers. With the help of a remotely operated position adjustment mechanism, the sensor array can be positioned to provide a uniform short spacing (mean 8.5 mm) between the sensor array and room temperature surface of the dewar. The sensors are connected to superconducting quantum interference devices (SQUIDs) operating at 4.2 K with median sensitivity levels of 7.5 fT/√Hz for the inner and 4 fT/√Hz for the outer layer sensors. SQUID outputs are digitized by a 24-bit acquisition system. A closed-cycle helium recycler provides maintenance-free continuous operation, eliminating the need for helium, with no interruption needed during MEG measurements. BabyMEG with the recycler has been fully operational from March, 2015. Ongoing spontaneous brain activity can be monitored in real time without interference from external magnetic noise sources including the recycler, using a combination of a lightly shielded two-layer magnetically shielded room, an external active shielding, a signal-space projection method, and a synthetic gradiometer approach. Evoked responses in the cortex can be clearly detected without averaging. These new design features and capabilities represent several advances in MEG, increasing the utility of this technique in basic neuroscience as well as in clinical research and patient studies.

Temperature-dependent performance of all-NbN DC-SQUID magnetometers

NASA Astrophysics Data System (ADS)

Liu, Quansheng; Wang, Huiwu; Zhang, Qiyu; Wang, Hai; Peng, Wei; Wang, Zhen

2017-05-01

Integrated NbN direct current superconducting quantum interference device (DC-SQUID) magnetometers were developed based on high-quality epitaxial NbN/AlN/NbN Josephson junctions for SQUID applications operating at high temperatures. We report the current-voltage and voltage-flux characteristics and the noise performance of the NbN DC-SQUIDs for temperatures ranging from 4.2 to 9 K. The critical current and voltage swing of the DC-SQUIDs decreased by 15% and 25%, respectively, as the temperature was increased from 4.2 to 9 K. The white flux noise of the DC-SQUID magnetometer at 1 kHz increased from 3.9 μΦ0/Hz1/2 at 4.2 K to 4.8 μΦ0/Hz1/2 at 9 K with 23% increase, corresponding to the magnetic field noise of 6.6 and 8.1 fT/Hz1/2, respectively. The results show that NbN DC-SQUIDs improve the tolerance of the operating temperatures and temperature fluctuations in SQUID applications.

NanoSQUIDs: Basics & recent advances

NASA Astrophysics Data System (ADS)

José Martínez-Pérez, Maria; Koelle, Dieter

2017-08-01

Superconducting Quantum Interference Devices (SQUIDs) are one of the most popular devices in superconducting electronics. They combine the Josephson effect with the quantization of magnetic flux in superconductors. This gives rise to one of the most beautiful manifestations of macroscopic quantum coherence in the solid state. In addition, SQUIDs are extremely sensitive sensors allowing us to transduce magnetic flux into measurable electric signals. As a consequence, any physical observable that can be converted into magnetic flux, e.g., current, magnetization, magnetic field or position, becomes easily accessible to SQUID sensors. In the late 1980s it became clear that downsizing the dimensions of SQUIDs to the nanometric scale would encompass an enormous increase of their sensitivity to localized tiny magnetic signals. Indeed, nanoSQUIDs opened the way to the investigation of, e.g., individual magnetic nanoparticles or surface magnetic states with unprecedented sensitivities. The purpose of this chapter is to present a detailed survey of microscopic and nanoscopic SQUID sensors. We will start by discussing the principle of operation of SQUIDs, placing the emphasis on their application as ultrasensitive detectors for small localized magnetic signals. We will continue by reviewing a number of existing devices based on different kinds of Josephson junctions and materials, focusing on their advantages and drawbacks. The last sections are left for applications of nanoSQUIDs in the fields of scanning SQUID microscopy and magnetic particle characterization, placing special stress on the investigation of individual magnetic nanoparticles.

Allometry indicates giant eyes of giant squid are not exceptional.

PubMed

Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Gamarra, Ashlee R; Lee, Johanna J; Wainwright, Peter C

2013-02-18

The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone.

Morphological beak differences of loliginid squid, Uroteuthis chinensis and Uroteuthis edulis, in the northern South China Sea

NASA Astrophysics Data System (ADS)

Jin, Yue; Liu, Bilin; Chen, Xinjun; Staples, Kevin

2018-03-01

The mitre squid ( Uroteuthis chinensis) and the swordtip squid ( U. edulis) are Indo-Pacific cephalopod species that are abundant in the western Pacific Ocean. They are currently exploited in the East and South China Seas and make up a significant portion of the Chinese neritic squid catch. Beaks, the feeding organs of squid, are important for individual size and biomass estimation because of their high resistance to degradation in predator stomachs and consistent dimensions. In this study, 104 U. chinensis and 143 U. edulis individuals were sampled from northern South China Sea with mantle length from 70 to 260 mm and 96 to 284 mm, respectively. The results indicated that morphological beak values were greater for U. edulis, compared to U. chinensis, for upper hood length (UHL), upper crest length (UCL), upper lateral wall length (ULWL), lower crest length (LCL), and lower lateral wall length (LLWL). According to principal component analysis, UHL/ML, UCL/ML, ULWL/ML, LCL/ML, LLWL/ML and LWL/ML could represent the characteristics of beaks for U. chinensis, while UHL/ML, UCL/ML, ULWL/ML, LHL/ML, LCL/ML and LLWL/ML could represent it for U. edulis. According to Akaike's information criterion (AIC) values, a power function was the most suitable model for U. chinensis, while a linear function was the most suitable model for U. edulis. The beak variable-mantle length ratio (beak variable/mantle length) declined with the increasing of mantle length and declined sharply at the early stage of growth in both beaks and species. The ratio changed quickly after achieving the mantle length of 140 mm for U. chinensis, while the ratio changed quickly after 170 mm for U. edulis. Beaks in both species experienced sharper changes through maturity stage I to II than other maturity stages. This study gives us basic beak morphology information for U. chinensis and U. edulis in the East and South China Seas. Geometric morphological methods combined with dietary analysis should be used in the future.

Multispectral linear array visible and shortwave infrared sensors

NASA Astrophysics Data System (ADS)

Tower, J. R.; Warren, F. B.; Pellon, L. E.; Strong, R.; Elabd, H.; Cope, A. D.; Hoffmann, D. M.; Kramer, W. M.; Longsderff, R. W.

1984-08-01

All-solid state pushbroom sensors for multispectral linear array (MLA) instruments to replace mechanical scanners used on LANDSAT satellites are introduced. A buttable, four-spectral-band, linear-format charge coupled device (CCD) and a buttable, two-spectral-band, linear-format, shortwave infrared CCD are described. These silicon integrated circuits may be butted end to end to provide multispectral focal planes with thousands of contiguous, in-line photosites. The visible CCD integrated circuit is organized as four linear arrays of 1024 pixels each. Each array views the scene in a different spectral window, resulting in a four-band sensor. The shortwave infrared (SWIR) sensor is organized as 2 linear arrays of 512 detectors each. Each linear array is optimized for performance at a different wavelength in the SWIR band.

Low noise niobium dc SQUID with a planar input coil

NASA Astrophysics Data System (ADS)

de Waal, V. J.; van den Hamer, P.; Klapwijk, T. M.

1983-02-01

A practical all-niobium dc superconducting quantum interference device (SQUID) with a niobium spiral input coil has been developed. The SQUID utilizes submicron Josephson junctions. The best intrinsic energy resolution obtained with a 1-nH SQUID is 4×10-32 J/Hz. A 20-turn 1.2-μH input coil is coupled to a 2.3-nH SQUID with an efficiency of 0.5. The energy resolution with respect to the coil is 1×10-30 J/Hz.

High temperature superconductor dc-SQUID microscope with a soft magnetic flux guide

NASA Astrophysics Data System (ADS)

Poppe, U.; Faley, M. I.; Zimmermann, E.; Glaas, W.; Breunig, I.; Speen, R.; Jungbluth, B.; Soltner, H.; Halling, H.; Urban, K.

2004-05-01

A scanning SQUID microscope based on high-temperature superconductor (HTS) dc-SQUIDs was developed. An extremely soft magnetic amorphous foil was used to guide the flux from room temperature samples to the liquid-nitrogen-cooled SQUID sensor and back. The flux guide passes through the pick-up loop of the HTS SQUID, providing an improved coupling of magnetic flux of the object to the SQUID. The device measures the z component (direction perpendicular to the sample surface) of the stray field of the sample, which is rastered with submicron precision in the x-y direction by a motorized computer-controlled scanning stage. A lateral resolution better than 10 µm, with a field resolution of about 0.6 nT Hz-1/2 was achieved for the determination of the position of the current carrying thin wires. The presence of the soft magnetic foil did not significantly increase the flux noise of the SQUID.

Subranging technique using superconducting technology

DOEpatents

Gupta, Deepnarayan

2003-01-01

Subranging techniques using "digital SQUIDs" are used to design systems with large dynamic range, high resolution and large bandwidth. Analog-to-digital converters (ADCs) embodying the invention include a first SQUID based "coarse" resolution circuit and a second SQUID based "fine" resolution circuit to convert an analog input signal into "coarse" and "fine" digital signals for subsequent processing. In one embodiment, an ADC includes circuitry for supplying an analog input signal to an input coil having at least a first inductive section and a second inductive section. A first superconducting quantum interference device (SQUID) is coupled to the first inductive section and a second SQUID is coupled to the second inductive section. The first SQUID is designed to produce "coarse" (large amplitude, low resolution) output signals and the second SQUID is designed to produce "fine" (low amplitude, high resolution) output signals in response to the analog input signals.

Trophic niche of squids: Insights from isotopic data in marine systems worldwide

NASA Astrophysics Data System (ADS)

Navarro, Joan; Coll, Marta; Somes, Christoper J.; Olson, Robert J.

2013-10-01

Cephalopods are an important prey resource for fishes, seabirds, and marine mammals, and are also voracious predators on crustaceans, fishes, squid and zooplankton. Because of their high feeding rates and abundance, squids have the potential to exert control on the recruitment of commercially important fishes. In this review, we synthesize the available information for two intrinsic markers (δ15N and δ13C isotopic values) in squids for all oceans and several types of ecosystems to obtain a global view of the trophic niches of squids in marine ecosystems. In particular, we aimed to examine whether the trophic positions and trophic widths of squid species vary among oceans and ecosystem types. To correctly compare across systems, we adjusted squid δ15N values for the isotopic variability of phytoplankton at the base of the food web provided by an ocean circulation-biogeochemistry-isotope model. Studies that focused on the trophic ecology of squids using isotopic techniques were few, and most of the information on squids was from studies on their predators. Our results showed that squids occupy a large range of trophic positions and exploit a large range of trophic resources, reflecting the versatility of their feeding behavior and confirming conclusions from food-web models. Clear differences in both trophic position and trophic width were found among oceans and ecosystem types. The study also reinforces the importance of considering the natural variation in isotopic values when comparing the isotopic values of consumers inhabiting different ecosystems.

Statistical characterization of voltage-biased SQUIDs with weakly damped junctions

NASA Astrophysics Data System (ADS)

Liu, Chao; Zhang, Yi; Mück, Michael; Zhang, Shulin; Krause, Hans-Joachim; Braginski, Alex I.; Zhang, Guofeng; Wang, Yongliang; Kong, Xiangyan; Xie, Xiaoming; Offenhäusser, Andreas; Jiang, Mianheng

2013-06-01

Recently, it has been shown that voltage-biased readout of SQUIDs with weakly damped junctions (large Stewart-McCumber parameter βc, due to high shunt resistance) is useful for suppression of preamplifier noise. We experimentally studied the characteristics of 53 planar niobium-SQUID magnetometers with junction shunt resistors RJ nominally of 30 Ω fabricated on 5 × 5 mm2 chips. The field-to-flux transfer coefficient ∂B/∂Φ of the magnetometers was 1.5 nT/Φ0, with a SQUID loop inductance Ls of about 350 pH. The distributions of important SQUID parameters, such as the current swing Iswing, the dynamic resistance Rd, and the flux-to-voltage transfer coefficient ∂V/∂Φ, are given. Nearly all the SQUIDs could be stably operated in the voltage bias mode and their ∂V/∂Φ reached a large mean value of 380 μV/Φ0. In this case, the SQUIDs can be read out directly by a commercial operational amplifier without any additional means to suppress preamplifier noise. The mean flux noise of the SQUIDs was found to be 4.5 μΦ0 Hz-1/2, corresponding to a field resolution of 7 fT Hz-1/2. To demonstrate the applicability of these SQUIDs in the direct readout scheme, a simple four-channel SQUID gradiometer system was set up to perform magnetocardiography and magnetoencephalography measurements in a magnetically shielded room.

Identifying Pelagic Habitat Hotspots of Neon Flying Squid in the Temperate Waters of the Central North Pacific

PubMed Central

Alabia, Irene D.; Saitoh, Sei-Ichi; Mugo, Robinson; Igarashi, Hiromichi; Ishikawa, Yoichi; Usui, Norihisa; Kamachi, Masafumi; Awaji, Toshiyuki; Seito, Masaki

2015-01-01

We identified the pelagic habitat hotspots of the neon flying squid (Ommastrephes bartramii) in the central North Pacific from May to July and characterized the spatial patterns of squid aggregations in relation to oceanographic features such as mesoscale oceanic eddies and the Transition Zone Chlorophyll-a Front (TZCF). The data used for the habitat model construction and analyses were squid fishery information, remotely-sensed and numerical model-derived environmental data from May to July 1999–2010. Squid habitat hotspots were deduced from the monthly Maximum Entropy (MaxEnt) models and were identified as regions of persistent high suitable habitat across the 12-year period. The distribution of predicted squid habitat hotspots in central North Pacific revealed interesting spatial and temporal patterns likely linked with the presence and dynamics of oceanographic features in squid’s putative foraging grounds from late spring to summer. From May to June, the inferred patches of squid habitat hotspots developed within the Kuroshio-Oyashio transition zone (KOTZ; 37–40°N) and further expanded north towards the subarctic frontal zone (SAFZ; 40–44°N) in July. The squid habitat hotspots within the KOTZ and areas west of the dateline (160°W-180°) were likely influenced and associated with the highly dynamic and transient oceanic eddies and could possibly account for lower squid suitable habitat persistence obtained from these regions. However, predicted squid habitat hotspots located in regions east of the dateline (180°-160°W) from June to July, showed predominantly higher squid habitat persistence presumably due to their proximity to the mean position of the seasonally-shifting TZCF and consequent utilization of the highly productive waters of the SAFZ. PMID:26571118

Mismatch between the eye and the optic lobe in the giant squid.

PubMed

Liu, Yung-Chieh; Liu, Tsung-Han; Yu, Chun-Chieh; Su, Chia-Hao; Chiao, Chuan-Chin

2017-07-01

Giant squids ( Architeuthis ) are a legendary species among the cephalopods. They live in the deep sea and are well known for their enormous body and giant eyes. It has been suggested that their giant eyes are not adapted for the detection of either mates or prey at distance, but rather are best suited for monitoring very large predators, such as sperm whales, at distances exceeding 120 m and at a depth below 600 m (Nilsson et al. 2012 Curr. Biol. 22 , 683-688. (doi:10.1016/j.cub.2012.02.031)). However, it is not clear how the brain of giant squids processes visual information. In this study, the optic lobe of a giant squid ( Architeuthis dux , male, mantle length 89 cm), which was caught by local fishermen off the northeastern coast of Taiwan, was scanned using high-resolution magnetic resonance imaging in order to examine its internal structure. It was evident that the volume ratio of the optic lobe to the eye in the giant squid is much smaller than that in the oval squid ( Sepioteuthis lessoniana ) and the cuttlefish ( Sepia pharaonis ). Furthermore, the cell density in the cortex of the optic lobe is significantly higher in the giant squid than in oval squids and cuttlefish, with the relative thickness of the cortex being much larger in Architeuthis optic lobe than in cuttlefish. This indicates that the relative size of the medulla of the optic lobe in the giant squid is disproportionally smaller compared with these two cephalopod species. This morphological study of the giant squid brain, though limited only to the optic lobe, provides the first evidence to support that the optic lobe cortex, the visual information processing area in cephalopods, is well developed in the giant squid. In comparison, the optic lobe medulla, the visuomotor integration centre in cephalopods, is much less developed in the giant squid than other species. This finding suggests that, despite the giant eye and a full-fledged cortex within the optic lobe, the brain of giant squids has not evolved proportionally in terms of performing complex tasks compared with shallow-water cephalopod species.

Non-destructive Testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

NASA Technical Reports Server (NTRS)

Lu, D. F.; Fan, Chang-Xin; Ruan, J. Z.; Han, S. G.; Wong, K. W.; Sun, G. F.

1995-01-01

A SQUID is the most sensitive device to detect change in magnetic field. A nondestructive testing (NDT) device using high temperature SQUID's and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUID's. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology.

Technical and commerical challenges in high Tc SQUIDs and their industrial applications

NASA Technical Reports Server (NTRS)

Lu, D. F.

1995-01-01

A SQUID is the most sensitive device for measuring changes in magnetic flux. Since its discovery in the sixties, scientists have made consistent efforts to apply SQUID's to various applications. Instruments that are the most sensitive in their respective categories have been built, such as SQUID DC susceptometer that is now manufactured by Quantum Design, pico-voltmeter which could measure 10(exp -14) volts, and gravitational wave detectors. One of the most successful applications of SQUID's is in magnetoencephalography, a non-invasive technique for investigating neuronal activity in the living human brain. This technique employs a multi-channel SQUID magnetometer that maps the weak magnetic field generated by small current when information is processed in brain, and its performance is marvelous.

One-dimensional sections of exotic spacetimes with superconducting circuits

NASA Astrophysics Data System (ADS)

Sabín, Carlos

2018-05-01

We introduce analogue quantum simulations of 1 + 1 dimensional sections of exotic 3 + 1 dimensional spacetimes, such as Alcubierre warp-drive spacetime, Gödel rotating universe and Kerr highly-rotating black hole metric. Suitable magnetic flux profiles along a SQUID array embedded in a superconducting transmission line allow to generate an effective spatiotemporal dependence in the speed of light, which is able to mimic the corresponding light propagation in a dimensionally-reduced exotic spacetime. In each case, we discuss the technical constraints and the links with possible chronology protection mechanisms and we find the optimal region of parameters for the experimental implementation.

Advanced ACTPol Low-Frequency Array: Readout and Characterization of Prototype 27 and 39 GHz Transition Edge Sensors

NASA Astrophysics Data System (ADS)

Koopman, B. J.; Cothard, N. F.; Choi, S. K.; Crowley, K. T.; Duff, S. M.; Henderson, S. W.; Ho, S. P.; Hubmayr, J.; Gallardo, P. A.; Nati, F.; Niemack, M. D.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Vavagiakis, E. M.; Wollack, E. J.

2018-05-01

Advanced ACTPol (AdvACT) is a third-generation polarization upgrade to the Atacama Cosmology Telescope, designed to observe the cosmic microwave background (CMB). AdvACT expands on the 90 and 150 GHz transition edge sensor (TES) bolometer arrays of the ACT Polarimeter (ACTPol), adding both high-frequency (HF, 150/230 GHz) and low-frequency (LF, 27/39 GHz) multichroic arrays. The addition of the high- and low-frequency detectors allows for the characterization of synchrotron and spinning dust emission at the low frequencies and foreground emission from galactic dust and dusty star-forming galaxies at the high frequencies. The increased spectral coverage of AdvACT will enable a wide range of CMB science, such as improving constraints on dark energy, the sum of the neutrino masses, and the existence of primordial gravitational waves. The LF array will be the final AdvACT array, replacing one of the MF arrays for a single season. Prior to the fabrication of the final LF detector array, we designed and characterized prototype TES bolometers. Detector geometries in these prototypes are varied in order to inform and optimize the bolometer designs for the LF array, which requires significantly lower noise levels and saturation powers (as low as {˜ } 1 pW) than the higher-frequency detectors. Here we present results from tests of the first LF prototype TES detectors for AdvACT, including measurements of the saturation power, critical temperature, thermal conductance, and time constants. We also describe the modifications to the time-division SQUID readout architecture compared to the MF and HF arrays.

Resolution of Port/Starboard Ambiguity Using a Linear Array of Triplets and a Twin-Line Planar Array

DTIC Science & Technology

2016-06-01

STARBOARD AMBIGUITY USING A LINEAR ARRAY OF TRIPLETS AND A TWIN- LINE PLANAR ARRAY by Stilson Veras Cardoso June 2016 Thesis Advisor...OF TRIPLETS AND A TWIN-LINE PLANAR ARRAY 5. FUNDING NUMBERS 6. AUTHOR(S) Stilson Veras Cardoso 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...A LINEAR ARRAY OF TRIPLETS AND A TWIN-LINE PLANAR ARRAY Stilson Veras Cardoso Civilian, Brazilian Navy B.S., University of Brasília, 1993

Effect of Melanin Free Ink Extracted From Squid (Loligo sp.) on Proximate and Sensory Characteristics of Soft-Bone Milkfish (Chanos chanos) During Storage

NASA Astrophysics Data System (ADS)

Winarni Agustini, Tri; Hadiyanto; Wijayanti, Ima; Amalia, Ulfah; Benjakul, Soottawat

2018-02-01

Antioxidant could be extracted and isolated from squid inks. Squid ink in the form of melanin free ink (MFI) could be act as an electron donor which can stabilize free radicals in lipid oxidation. This study was carried out to assess the antioxidant activity of squid inks converted into MFI in different dilution and to optimize the extraction conditions for the application of MFI as an antioxidative agent on fish product. Three different types of MFI extracts i.e : pure squid ink, squid ink with 5 times dilution and squid ink with 10 times dilutions by using cooled ionized water (4°C). The ink was then centrifuged at 18.000 x g for 30 minutes at cooled centrifuge (4°C) followed by DPPH analysis. The results showed that the IC50 of MFI extracts were 2.84 ppm; 1.11 ppm and 0.34 ppm, respectively (p < 0.05). The results indicated that squid ink with 10 times dilution in extraction of MFI had the highest value in free radical inhibitory. Although the IC50 of three different dilutions are equally low, and are considered as very strong antioxidative agent, however, it showed that the MFI extracted from squid ink had the ability to prevent free radical

Development of multichannel MEG system at IGCAR

NASA Astrophysics Data System (ADS)

Mariyappa, N.; Parasakthi, C.; Gireesan, K.; Sengottuvel, S.; Patel, Rajesh; Janawadkar, M. P.; Radhakrishnan, T. S.; Sundar, C. S.

2013-02-01

We describe some of the challenging aspects in the indigenous development of the whole head multichannel magnetoencephalography (MEG) system at IGCAR, Kalpakkam. These are: i) fabrication and testing of a helmet shaped sensor array holder of a polymeric material experimentally tested to be compatible with liquid helium temperatures, ii) the design and fabrication of the PCB adapter modules, keeping in mind the inter-track cross talk considerations between the electrical leads used to provide connections from SQUID at liquid helium temperature (4.2K) to the electronics at room temperature (300K) and iii) use of high resistance manganin wires for the 86 channels (86×8 leads) essential to reduce the total heat leak which, however, inevitably causes an attenuation of the SQUID output signal due to voltage drop in the leads. We have presently populated 22 of the 86 channels, which include 6 reference channels to reject the common mode noise. The whole head MEG system to cover all the lobes of the brain will be progressively assembled when other three PCB adapter modules, presently under fabrication, become available. The MEG system will be used for a variety of basic and clinical studies including localization of epileptic foci during pre-surgical mapping in collaboration with neurologists.

Toward Large FOV High-Resolution X-Ray Imaging Spectrometer: Microwave Multiplexed Readout of 32 TES Microcalorimeters

NASA Technical Reports Server (NTRS)

Yoon, Wonsik; Adams, Joseph S.; Bandler, Simon R.; Chervenak, James A.; Datesman, Aaron M.; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; Miniussi, Antoine R.;

Non-destructive testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, D.F.; Fan, C.; Ruan, J.Z.

1994-12-31

A SQUID is the most sensitive device to detect change in magnetic field. A non-destructive testing (NDT) device using high temperature SQUIDs and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUIDs. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDTmore » device will have a significant impact on metal corrosion or crack detection technology.« less

Quantum information transfer and entanglement with SQUID qubits in cavity QED: a dark-state scheme with tolerance for nonuniform device parameter.

PubMed

Yang, Chui-Ping; Chu, Shih-I; Han, Siyuan

2004-03-19

We investigate the experimental feasibility of realizing quantum information transfer (QIT) and entanglement with SQUID qubits in a microwave cavity via dark states. Realistic system parameters are presented. Our results show that QIT and entanglement with two-SQUID qubits can be achieved with a high fidelity. The present scheme is tolerant to device parameter nonuniformity. We also show that the strong coupling limit can be achieved with SQUID qubits in a microwave cavity. Thus, cavity-SQUID systems provide a new way for production of nonclassical microwave source and quantum communication.

Development of improved superconductive axial gradiometers for biomagnetic SQUID applications

NASA Astrophysics Data System (ADS)

Budnyk, M. M.; Minov, Yu. D.; Lyakhno, V. Yu.; Desnenko, V. A.; Linnik, A. S.; Shopen, O. B.

2018-03-01

SQUID magnetometers for biomagnetic measurements are equipped with superconductive gradiometers which are required to provide a high signal-to-noise ratio at low frequencies, sufficient mechanical strength and sustained performance under repeated thermal cycles, as well as a low level of intrinsic magnetic noise. This paper describes the design of a gradiometer made with a carbon-fiber reinforced composite material for magnetic cardiography measurements. The thermal coefficient of linear expansion (TCLE) of the carbon fiber composite can be precisely adjusted to match that of the superconducting detector coil wire. This is achieved thanks to the difference in the TCLE of carbon fibers in the longitudinal and transverse directions and is realized by varying the laying directions of the fiber in the composite. The data of magnetic susceptibility measurements on carbon fiber composite are reported, showing the magnetic susceptibility about six times smaller than that of graphite. The presented gradiometer design provides a high degree of balancing and is patented along side other specific techniques.

Linear arrangements of nano-scale ferromagnetic particles spontaneously formed in a copper-base Cu-Ni-Co alloy

NASA Astrophysics Data System (ADS)

Sakakura, Hibiki; Kim, Jun-Seop; Takeda, Mahoto

2018-03-01

We have investigated the influence of magnetic interactions on the microstructural evolution of nano-scale granular precipitates formed spontaneously in an annealed Cu-20at%Ni-5at%Co alloy and the associated changes of magnetic properties. The techniques used included transmission electron microscopy, superconducting quantum interference device (SQUID) magnetometry, magneto-thermogravimetry (MTG), and first-principles calculations based on the method of Koster-Korringa-Rostker with the coherent potential approximation. Our work has revealed that the nano-scale spherical and cubic precipitates which formed on annealing at 873 K and 973 K comprise mainly cobalt and nickel with a small amount of copper, and are arranged in the 〈1 0 0〉 direction of the copper matrix. The SQUID and MTG measurements suggest that magnetic properties such as coercivity and Curie temperature are closely correlated with the microstructure. The combination of results suggests that magnetic interactions between precipitates during annealing can explain consistently the observed precipitation phenomena.

Analytical balance-based Faraday magnetometer

NASA Astrophysics Data System (ADS)

Riminucci, Alberto; Uhlarz, Marc; De Santis, Roberto; Herrmannsdörfer, Thomas

2017-03-01

We introduce a Faraday magnetometer based on an analytical balance in which we were able to apply magnetic fields up to 0.14 T. We calibrated it with a 1 mm Ni sphere previously characterized in a superconducting quantum interference device (SQUID) magnetometer. The proposed magnetometer reached a theoretical sensitivity of 3 × 10-8 A m2. We demonstrated its operation on magnetic composite scaffolds made of poly(ɛ-caprolactone)/iron-doped hydroxyapatite. To confirm the validity of the method, we measured the same scaffold properties in a SQUID magnetometer. The agreement between the two measurements was within 5% at 0.127 T and 12% at 24 mT. With the addition, for a small cost, of a permanent magnet and computer controlled linear translators, we were thus able to assemble a Faraday magnetometer based on an analytical balance, which is a virtually ubiquitous instrument. This will make simple but effective magnetometry easily accessible to most laboratories, in particular, to life sciences ones, which are increasingly interested in magnetic materials.

The mechanics of locomotion in the squid Loligo pealei: locomotory function and unsteady hydrodynamics of the jet and intramantle pressure.

PubMed

Anderson, E J; DeMont, M E

2000-09-01

High-speed, high-resolution digital video recordings of swimming squid (Loligo pealei) were acquired. These recordings were used to determine very accurate swimming kinematics, body deformations and mantle cavity volume. The time-varying squid profile was digitized automatically from the acquired swimming sequences. Mantle cavity volume flow rates were determined under the assumption of axisymmetry and the condition of incompressibility. The data were then used to calculate jet velocity, jet thrust and intramantle pressure, including unsteady effects. Because of the accurate measurements of volume flow rate, the standard use of estimated discharge coefficients was avoided. Equations for jet and whole-cycle propulsive efficiency were developed, including a general equation incorporating unsteady effects. Squid were observed to eject up to 94 % of their intramantle working fluid at relatively high swimming speeds. As a result, the standard use of the so-called large-reservoir approximation in the determination of intramantle pressure by the Bernoulli equation leads to significant errors in calculating intramantle pressure from jet velocity and vice versa. The failure of this approximation in squid locomotion also implies that pressure variation throughout the mantle cannot be ignored. In addition, the unsteady terms of the Bernoulli equation and the momentum equation proved to be significant to the determination of intramantle pressure and jet thrust. Equations of propulsive efficiency derived for squid did not resemble Froude efficiency. Instead, they resembled the equation of rocket motor propulsive efficiency. The Froude equation was found to underestimate the propulsive efficiency of the jet period of the squid locomotory cycle and to overestimate whole-cycle propulsive efficiency when compared with efficiencies calculated from equations derived with the squid locomotory apparatus in mind. The equations for squid propulsive efficiency reveal that the refill period of squid plays a greater role, and the jet period a lesser role, in the low whole-cycle efficiencies predicted in squid and similar jet-propelled organisms. These findings offer new perspectives on locomotory hydrodynamics, intramantle pressure measurements and functional morphology with regard to squid and other jet-propelled organisms.

Prolonged Decline of Jumbo Squid (Dosidicus gigas) Landings in the Gulf of California is Associated with Chronically low wind Stress and Decreased Chlorophyll a after El Niño 2009-2010

NASA Astrophysics Data System (ADS)

Robinson, C. J.; Gomez-Gutierrez, J.

2016-02-01

Dosidicus gigas (jumbo squid) is an ecologically relevant predator in the Gulf of California, Mexico, where it supports an economically valuable fishery. The commercial jumbo squid fishery in the Gulf declined steeply after an El Niño event in 2009-2010, and subsequent landings have remained at historically low levels in the relevant squid fishing centers (Guaymas, Sonora, and Santa Rosalia, Baja California Sur). In this paper, we examined wind speed and satellite chlorophyll a concentrations on the jumbo squid fishing grounds as factors that would be expected to be relevant to this prolonged period of low landings. Analysis from local weather stations, remote sensing and fishery data showed that low jumbo squid landings from 2010 to 2015 occurred during a period abnormally weak winter/spring winds and extremely low chlorophyll a concentrations off the East Guaymas Basin. Results indicate that the squid fishing area in the Guaymas region has been chronically impoverished during this period, and that this area may no longer be a productive habitat for jumbo squid. In response to this decreased productivity, size-at-maturity of jumbo squid showed a drastic decrease over the same period. Results are compared with the effect of El Niño 1997-1998 on the jumbo squid fishery and size-at-maturity of this species in the Gulf of California. The key difference between the recovery phases for El Niño 1997-1998 versus El Niño2009-2010 was the wind intensity as measured in the Guaymas fishing area.

Principle and experimental investigation of current-driven negative-inductance superconducting quantum interference device

NASA Astrophysics Data System (ADS)

Li, Hao; Liu, Jianshe; Zhang, Yingshan; Cai, Han; Li, Gang; Liu, Qichun; Han, Siyuan; Chen, Wei

2017-03-01

A negative-inductance superconducting quantum interference device (nSQUID) is an adiabatic superconducting logic device with high energy efficiency, and therefore a promising building block for large-scale low-power superconducting computing. However, the principle of the nSQUID is not that straightforward and an nSQUID driven by voltage is vulnerable to common mode noise. We investigate a single nSQUID driven by current instead of voltage, and clarify the principle of the adiabatic transition of the current-driven nSQUID between different states. The basic logic operations of the current-driven nSQUID with proper parameters are simulated by WRspice. The corresponding circuit is fabricated with a 100 A cm-2 Nb-based lift-off process, and the experimental results at low temperature confirm the basic logic operations as a gated buffer.

The LiteBIRD Satellite Mission: Sub-Kelvin Instrument

NASA Astrophysics Data System (ADS)

Suzuki, A.; Ade, P. A. R.; Akiba, Y.; Alonso, D.; Arnold, K.; Aumont, J.; Baccigalupi, C.; Barron, D.; Basak, S.; Beckman, S.; Borrill, J.; Boulanger, F.; Bucher, M.; Calabrese, E.; Chinone, Y.; Cho, S.; Crill, B.; Cukierman, A.; Curtis, D. W.; de Haan, T.; Dobbs, M.; Dominjon, A.; Dotani, T.; Duband, L.; Ducout, A.; Dunkley, J.; Duval, J. M.; Elleflot, T.; Eriksen, H. K.; Errard, J.; Fischer, J.; Fujino, T.; Funaki, T.; Fuskeland, U.; Ganga, K.; Goeckner-Wald, N.; Grain, J.; Halverson, N. W.; Hamada, T.; Hasebe, T.; Hasegawa, M.; Hattori, K.; Hattori, M.; Hayes, L.; Hazumi, M.; Hidehira, N.; Hill, C. A.; Hilton, G.; Hubmayr, J.; Ichiki, K.; Iida, T.; Imada, H.; Inoue, M.; Inoue, Y.; Irwin, K. D.; Ishino, H.; Jeong, O.; Kanai, H.; Kaneko, D.; Kashima, S.; Katayama, N.; Kawasaki, T.; Kernasovskiy, S. A.; Keskitalo, R.; Kibayashi, A.; Kida, Y.; Kimura, K.; Kisner, T.; Kohri, K.; Komatsu, E.; Komatsu, K.; Kuo, C. L.; Kurinsky, N. A.; Kusaka, A.; Lazarian, A.; Lee, A. T.; Li, D.; Linder, E.; Maffei, B.; Mangilli, A.; Maki, M.; Matsumura, T.; Matsuura, S.; Meilhan, D.; Mima, S.; Minami, Y.; Mitsuda, K.; Montier, L.; Nagai, M.; Nagasaki, T.; Nagata, R.; Nakajima, M.; Nakamura, S.; Namikawa, T.; Naruse, M.; Nishino, H.; Nitta, T.; Noguchi, T.; Ogawa, H.; Oguri, S.; Okada, N.; Okamoto, A.; Okamura, T.; Otani, C.; Patanchon, G.; Pisano, G.; Rebeiz, G.; Remazeilles, M.; Richards, P. L.; Sakai, S.; Sakurai, Y.; Sato, Y.; Sato, N.; Sawada, M.; Segawa, Y.; Sekimoto, Y.; Seljak, U.; Sherwin, B. D.; Shimizu, T.; Shinozaki, K.; Stompor, R.; Sugai, H.; Sugita, H.; Suzuki, J.; Tajima, O.; Takada, S.; Takaku, R.; Takakura, S.; Takatori, S.; Tanabe, D.; Taylor, E.; Thompson, K. L.; Thorne, B.; Tomaru, T.; Tomida, T.; Tomita, N.; Tristram, M.; Tucker, C.; Turin, P.; Tsujimoto, M.; Uozumi, S.; Utsunomiya, S.; Uzawa, Y.; Vansyngel, F.; Wehus, I. K.; Westbrook, B.; Willer, M.; Whitehorn, N.; Yamada, Y.; Yamamoto, R.; Yamasaki, N.; Yamashita, T.; Yoshida, M.

2018-05-01

Inflation is the leading theory of the first instant of the universe. Inflation, which postulates that the universe underwent a period of rapid expansion an instant after its birth, provides convincing explanation for cosmological observations. Recent advancements in detector technology have opened opportunities to explore primordial gravitational waves generated by the inflation through "B-mode" (divergent-free) polarization pattern embedded in the cosmic microwave background anisotropies. If detected, these signals would provide strong evidence for inflation, point to the correct model for inflation, and open a window to physics at ultra-high energies. LiteBIRD is a satellite mission with a goal of detecting degree-and-larger-angular-scale B-mode polarization. LiteBIRD will observe at the second Lagrange point with a 400 mm diameter telescope and 2622 detectors. It will survey the entire sky with 15 frequency bands from 40 to 400 GHz to measure and subtract foregrounds. The US LiteBIRD team is proposing to deliver sub-Kelvin instruments that include detectors and readout electronics. A lenslet-coupled sinuous antenna array will cover low-frequency bands (40-235 GHz) with four frequency arrangements of trichroic pixels. An orthomode-transducer-coupled corrugated horn array will cover high-frequency bands (280-402 GHz) with three types of single frequency detectors. The detectors will be made with transition edge sensor (TES) bolometers cooled to a 100 milli-Kelvin base temperature by an adiabatic demagnetization refrigerator. The TES bolometers will be read out using digital frequency multiplexing with Superconducting QUantum Interference Device (SQUID) amplifiers. Up to 78 bolometers will be multiplexed with a single SQUID amplifier. We report on the sub-Kelvin instrument design and ongoing developments for the LiteBIRD mission.

SQUIDs: microscopes and nondestructive evaluation

NASA Astrophysics Data System (ADS)

Mück, Michael

2005-03-01

SQUIDs (Superconducting Quantum Interference Devices) are magnetic field sensores with unsurpassed sensitivity. They are amazingly versatile, being able to measure all physical quantities which can be converted to magnetic flux. They are routinely fabricated in thin film technology from two classes of superconducting materials: high-temperature superconductors (HTS) which are usually cooled to 77 K, and low-temperature superconductors (LTS), which have to be cooled to 4.2 K. SQUIDs have many applications, two of which shall be discussed in this paper. In SQUID microscopy, a SQUID scans a sample, which preferrably is at room temperature, and measures the two-dimensional magnetic field distribution at the surface of the sample. In order to achieve a relatively high spatial resolution, the stand-off distance between the sample and the SQUID is made as small as possible. SQUIDs show also promising results in the field of nondestructive testing of various materials. For example, ferromagnetic impurities in stainless steel formed by aging processes in the material can be detected with high probability, and cracks in conducting materials, for example aircraft parts, can be located using eddy current methods. Especially for the case of thick, highly conductive, or ferromagnetic materials, as well as sintered materials, it can be shown that a SQUID-based NDE system exhibits a much higher sensitivity compared to conventional eddy current NDE and ultrasonic testing.

Cadmium content in fresh and canned squid (Loligo opalescens) from the Pacific coastal waters of California (USA).

PubMed

Galitsopoulou, A; Georgantelis, D; Kontominas, M G

2009-01-01

Cadmium (Cd) levels were determined in 70 samples of mantle tissue and 70 whole individual squid (Loligo opalescens; commercially known as California squid). Samples were collected from the coastal zones of California (USA) during the period 2007/2008. To further investigate consumer exposure to processed fishery products, cadmium concentration was also determined in 200 canned samples of squid. Cd concentrations in raw mantle were low, between 0.01 and 0.29 mg kg(-1) and below the tolerance limit of current regulations (1 mg kg(-1)). Respective concentrations in whole individuals were significantly higher, ranging from 0.51 to 1.18 mg kg(-1), attributed to the presence of the visceral portion in whole squid samples. Cd concentrations varied in relation to age and sex of squid, indicating that several physiological factors may influence accumulation. Furthermore, canning of squid substantially enhanced Cd levels. Cd concentration ranged 0.17-0.67 mg kg(-1) in canned mantle tissue and 0.86-2.07 mg kg(-1) in canned whole squid samples, due to both concentration after canning and movement of the metal between different tissues. Several biological compounds, including metallothioneins, nucleic acids and enzymes, may affect Cd concentrations in commercial fishery products.

Large format imaging arrays for the Atacama Cosmology Telescope

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Wollack, E. J.; Marraige, T.; Staggs, S.; Niemack, M.; Doriese, B.

2006-01-01

We describe progress in the fabrication, characterization, and production of detector arrays for the Atacama Cosmology Telescope (ACT). The completed ACT instrument is specified to image simultaneously at 145, 225, and 265 GHz using three 32x32 filled arrays of superconducting transition edge sensors (TES) read out with time-division-multiplexed SQUID amplifiers. We present details of the pixel design and testing including the optimization of the electrical parameters for multiplexed readout. Using geometric noise suppression and careful tuning of operation temperature and device bias resistance, the excess noise in the TES devices is balanced with detector speed for interfacing with the ACT optics. The design also accounts for practical tolerances such as transition temperature gradients and scatter that occur in the production of multiple wafers to populate fully the kilopixel cameras. We have developed an implanted absorber layer compatible with our silicon-on-insulator process that allows for tunable optical resistance with requisite on-wafer uniformity and wafer-to-wafer reproducibility. Arrays of 32 elements have been tested in the laboratory environment including electrical, optical, and multiplexed performance. Given this pixel design, optical tests and modeling are used to predict the performance of the filled array under anticipated viewing conditions. Integration of the filled array of pixels with a tuned backshort and dielectric plate in front of the array maximize absorption and the focal plane and suppress reflections. A mechanical design for the build of the full structure is completed and we report on progress toward the construction of a prototype array for first light on the ACT.

Low Field Squid MRI Devices, Components and Methods

NASA Technical Reports Server (NTRS)

Hahn, Inseob (Inventor); Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor)

2013-01-01

Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

Low Field Squid MRI Devices, Components and Methods

NASA Technical Reports Server (NTRS)

Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

2014-01-01

Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

Low field SQUID MRI devices, components and methods

NASA Technical Reports Server (NTRS)

Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

2011-01-01

Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

Low field SQUID MRI devices, components and methods

NASA Technical Reports Server (NTRS)

Penanen, Konstantin I. (Inventor); Eom, Byeong H (Inventor); Hahn, Inseob (Inventor)

2010-01-01

Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

The UT 19-channel DC SQUID based neuromagnetometer.

PubMed

ter Brake, H J; Flokstra, J; Jaszczuk, W; Stammis, R; van Ancum, G K; Martinez, A; Rogalla, H

1991-01-01

A 19-channel DC SQUID based neuromagnetometer is under construction at the University of Twente (UT). Except for the cryostat all elements of the system are developed at the UT. It comprises 19 wire-wound first-order gradiometers in a hexagonal configuration. The gradiometers are connected to planar DC SQUIDs fabricated with a Nb/Al, AlO kappa/Nb technology. For this connection we developed a method to bond a Nb wire to a Nb thin-film. The SQUIDs are placed in compartmentalised Nb modules. Further, external feedback is incorporated in order to eliminate cross talk between the gradiometers. The electronics basically consist of a phase-locked loop operating with a modulation frequency of 100 kHz. Between SQUID and preamplifier a small transformer is used to limit the noise contribution of the preamplifier. In the paper the overall system is described, and special attention is paid to the SQUID module (bonding, compartments, external-feedback setup, output transformer).

Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

PubMed Central

Choi, Joon Hyuk; Kim, Kyung-Tae; Kim, Sang Moo

2015-01-01

Squid is one of the most important commercial fishes in the world and is mainly utilized or consumed as sliced raw fish or as processed products. The biofunctional activities of enzymatic squid meat hydrolysate were determined to develop value-added products. Enzymatic squid hydrolysate manufactured by Alcalase effectively quenched 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and hydrogen peroxide radical with IC50 values of 311, 3,410, and 111.5 μg/mL, respectively. Angiotensin I-converting enzyme inhibitory activity of squid hydrolysate was strong with an IC50 value of 145.1 μg/mL, while tyrosinase inhibitory activity with an IC50 value of 4.72 mg/mL was moderately low. Overall, squid meat hydrolysate can be used in food or cosmetic industries as a bioactive ingredient and possibly be used in the manufacture of seasoning, bread, noodle, or cosmetics. PMID:25866752

Superconducting quantum interference device with frequency-dependent damping: Readout of flux qubits

NASA Astrophysics Data System (ADS)

Robertson, T. L.; Plourde, B. L. T.; Hime, T.; Linzen, S.; Reichardt, P. A.; Wilhelm, F. K.; Clarke, John

2005-07-01

Recent experiments on superconducting flux qubits, consisting of a superconducting loop interrupted by Josephson junctions, have demonstrated quantum coherence between two different quantum states. The state of the qubit is measured with a superconducting quantum interference device (SQUID). Such measurements require the SQUID to have high resolution while exerting minimal backaction on the qubit. By designing shunts across the SQUID junctions appropriately, one can improve the measurement resolution without increasing the backaction significantly. Using a path-integral approach to analyze the Caldeira-Leggett model, we calculate the narrowing of the distribution of the switching events from the zero-voltage state of the SQUID for arbitrary shunt admittances, focusing on shunts consisting of a capacitance Cs and resistance Rs in series. To test this model, we fabricated a dc SQUID in which each junction is shunted with a thin-film interdigitated capacitor in series with a resistor, and measured the switching distribution as a function of temperature and applied magnetic flux. After accounting for the damping due to the SQUID leads, we found good agreement between the measured escape rates and the predictions of our model. We analyze the backaction of a shunted symmetric SQUID on a flux qubit. For the given parameters of our SQUID and realistic parameters for a flux qubit, at the degeneracy point we find a relaxation time of 113μs , which limits the decoherence time to 226μs . Based on our analysis of the escape process, we determine that a SQUID with purely capacitive shunts should have narrow switching distributions and no dissipation.

Apparatus for detecting a magnetic anomaly contiguous to remote location by squid gradiometer and magnetometer systems

DOEpatents

Overton, Jr., William C.; Steyert, Jr., William A.

1984-01-01

A superconducting quantum interference device (SQUID) magnetic detection apparatus detects magnetic fields, signals, and anomalies at remote locations. Two remotely rotatable SQUID gradiometers may be housed in a cryogenic environment to search for and locate unambiguously magnetic anomalies. The SQUID magnetic detection apparatus can be used to determine the azimuth of a hydrofracture by first flooding the hydrofracture with a ferrofluid to create an artificial magnetic anomaly therein.

Apparatus and method for detecting a magnetic anomaly contiguous to remote location by SQUID gradiometer and magnetometer systems

DOEpatents

Overton, W.C. Jr.; Steyert, W.A. Jr.

1981-05-22

A superconducting quantum interference device (SQUID) magnetic detection apparatus detects magnetic fields, signals, and anomalies at remote locations. Two remotely rotatable SQUID gradiometers may be housed in a cryogenic environment to search for and locate unambiguously magnetic anomalies. The SQUID magnetic detection apparatus can be used to determine the azimuth of a hydrofracture by first flooding the hydrofracture with a ferrofluid to create an artificial magnetic anomaly therein.

Whole-head SQUID system in a superconducting magnetic shield.

PubMed

Ohta, H; Matsui, T; Uchikawa, Y

2004-11-30

We have constructed a mobile whole-head SQUID system in a superconducting magnetic shield - a cylinder of high Tc superconductor BSCCO of 65 cm in diameter and 160 cm in length. We compared the noise spectra of several SQUID sensors of SNS Josephson junctions in the superconducting magnetic shield with those of the same SQUID sensors in a magnetically shielded room of Permalloy. The SQUID sensors in the superconducting magnetic shield are more than 100 times more sensitive than those in a magnetically shielded room of Permalloy below 1 Hz. We tested the whole-head SQUID system in the superconducting magnetic shield observing somatosensory signals evoked by stimulating the median nerve in the right wrist of patients by current pulses. We present data of 64 and 128 traces versus the common time axis for comparison. Most sensory responses of human brains phase out near 250 ms. However monotonic rhythms still remain even at longer latencies than 250 ms. The nodes of these rhythm are very narrow even at these longer latencies just indicating low noise characteristics of the SQUID system at low-frequencies. The current dipoles at the secondary somatosensory area SII are evoked at longer latencies than 250 ms contributing to a higher-level brain function. The SQUID system in a superconducting magnetic shield will also have advantages when it is used as a DC MEG to study very slow activities and function of the brain.

Potential use of stable isotope and fatty acid analyses for traceability of geographic origins of jumbo squid (Dosidicus gigas).

PubMed

Gong, Yi; Li, Yunkai; Chen, Xinjun; Chen, Ling

2018-04-15

Squid is an important seafood resource for Asian and European countries. With the continuous development of processed squid products, an effective traceability system has become increasingly prominent. Here, we attempt to trace the fishery products of the main target species, jumbo squid (Dosidicus gigas), by using biochemical tracers. Carbon and nitrogen isotope ratios (δ 13 C and δ 15 N values) and fatty acid profiles were identified in squid from three harvest locations in the eastern Pacific Ocean by isotope ratio mass spectrometry and gas chromatography/mass spectrometry, respectively. Comparative analysis was used to evaluate the geographic variations in tracers and to identify the suitable discriminatory variables among origins. Significant spatial variations were found in isotopic values and fatty acid profiles in squid muscle tissues, possibly because of different food availability and/or oceanographic conditions that each group experiences at a given location. The stepwise discriminant analysis indicated that δ 15 N, C16:1n7, C17:1n7, C18:2n6, C20:1 and C20:4n6 were effective variables at differentiating origin. Combined use of stable isotope ratios and fatty acid analyses could trace geographic origins of jumbo squid. This study provides an alternative approach for improving authenticity evaluation of commercial squid products. Copyright © 2018 John Wiley & Sons, Ltd.

Timing of squid migration reflects North Atlantic climate variability.

PubMed

Sims, D W; Genner, M J; Southward, A J; Hawkins, S J

2001-12-22

The environmental and biotic conditions affecting fisheries for cephalopods are only partially understood. A problem central to this is how climate change may influence population movements by altering the availability of thermal resources. In this study we investigate the links between climate and sea-temperature changes and squid arrival time off southwestern England over a 20-year period. We show that veined squid (Loligo forbesi) migrate eastward in the English Channel earlier when water in the preceding months is warmer, and that higher temperatures and early arrival correspond with warm (positive) phases of the North Atlantic oscillation (NAO). The timing of squid peak abundance advanced by 120-150 days in the warmest years ('early' years) compared with the coldest ('late' years). Furthermore, sea-bottom temperature was closely linked to the extent of squid movement. Temperature increases over the five months prior to and during the month of peak squid abundance did not differ between early and late years, indicating squid responded to temperature changes independently of time of year. We conclude that the temporal variation in peak abundance of squid seen off Plymouth represents temperature-dependent movement, which is in turn mediated by climatic changes associated with the NAO. Such climate-mediated movement may be a widespread characteristic of cephalopod populations worldwide, and may have implications for future fisheries management because global warming may alter both the timing and location of peak population abundance.

Therapeutic Significance of Loligo vulgaris (Lamarck, 1798) ink Extract: A Biomedical Approach.

PubMed

Nadarajah, Sri Kumaran; Vijayaraj, Radha; Mani, Jayaprakashvel

2017-12-01

The squid ink extract is well known for its biomedical properties. In this study, squid Loligo vulgaris was collected from Tuticorin costal water, Bay of Bengal, India. Proximate composition of the crude squid ink was studied and found to have protein as the major component over lipid and carbohydrates. Further, bioactive fractions of squid ink were extracted with ethanol, and therapeutic applications such as hemolytic, antioxidant, antimicrobial, and in vitro anti-inflammatory properties were analyzed using standard methods. In hemolytic assay, the squid ink extract exhibited a maximum hemolytic activity of 128 hemolytic unit against tested erythrocytes. In DPPH assay, the ethanolic extract of squid ink has exhibited an antioxidant activity of 83.5%. The squid ink was found to be potent antibacterial agent against the pathogens tested. 200 μL of L. vulgaris ink extract showed remarkable antibacterial activity as zone of inhibition against Escherichia coli (28 mm), Klebsiella pneumoniae (22 mm), Pseudomonas aeruginosa (21 mm), and Staphylococcus aureus (24 mm). The 68.9% inhibition of protein denaturation by the squid ink extract indicated that it has very good in vitro anti-inflammatory properties. The Fourier transform infrared spectroscopy analysis of the ethanolic extracts of the squid ink indicated the presence of functional groups such as 1° and 2° amines, amides, alkynes (terminal), alkenes, aldehydes, nitriles, alkanes, aliphatic amines, carboxylic acids, and alkyl halides, which complements the biochemical background of therapeutic applications. Hence, results of this study concluded that the ethanolic extract of L. vulgaris has many therapeutic applications such as antimicrobial, antioxidant, and anti-inflammatory activities. Squid ink is very high in a number of important nutrients. It's particularly high in antioxidants for instance, which as well all know help to protect the cells and the heart against damage from free radicals. In the present study, the squid ink have antioxidant, anti-inflammatory and cytotoxic properties and can be considered as promising the developing the drugs. Abbreviations Used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, FTIR: Fourier-transform infrared spectroscopy, BSA: Bovine Serum Albumin.

Therapeutic Significance of Loligo vulgaris (Lamarck, 1798) ink Extract: A Biomedical Approach

PubMed Central

Nadarajah, Sri Kumaran; Vijayaraj, Radha; Mani, Jayaprakashvel

2017-01-01

Background: The squid ink extract is well known for its biomedical properties. Objective: In this study, squid Loligo vulgaris was collected from Tuticorin costal water, Bay of Bengal, India. Materials and Methods: Proximate composition of the crude squid ink was studied and found to have protein as the major component over lipid and carbohydrates. Further, bioactive fractions of squid ink were extracted with ethanol, and therapeutic applications such as hemolytic, antioxidant, antimicrobial, and in vitro anti-inflammatory properties were analyzed using standard methods. Results: In hemolytic assay, the squid ink extract exhibited a maximum hemolytic activity of 128 hemolytic unit against tested erythrocytes. In DPPH assay, the ethanolic extract of squid ink has exhibited an antioxidant activity of 83.5%. The squid ink was found to be potent antibacterial agent against the pathogens tested. 200 μL of L. vulgaris ink extract showed remarkable antibacterial activity as zone of inhibition against Escherichia coli (28 mm), Klebsiella pneumoniae (22 mm), Pseudomonas aeruginosa (21 mm), and Staphylococcus aureus (24 mm). The 68.9% inhibition of protein denaturation by the squid ink extract indicated that it has very good in vitro anti-inflammatory properties. The Fourier transform infrared spectroscopy analysis of the ethanolic extracts of the squid ink indicated the presence of functional groups such as 1° and 2° amines, amides, alkynes (terminal), alkenes, aldehydes, nitriles, alkanes, aliphatic amines, carboxylic acids, and alkyl halides, which complements the biochemical background of therapeutic applications. Conclusion: Hence, results of this study concluded that the ethanolic extract of L. vulgaris has many therapeutic applications such as antimicrobial, antioxidant, and anti-inflammatory activities. SUMMARY Squid ink is very high in a number of important nutrients. It’s particularly high in antioxidants for instance, which as well all know help to protect the cells and the heart against damage from free radicals. In the present study, the squid ink have antioxidant, anti-inflammatory and cytotoxic properties and can be considered as promising the developing the drugs. Abbreviations Used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, FTIR: Fourier-transform infrared spectroscopy, BSA: Bovine Serum Albumin PMID:29333051

Towards a feasible implementation of quantum neural networks using quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Altaisky, Mikhail V., E-mail: altaisky@mx.iki.rssi.ru, E-mail: nzolnik@iki.rssi.ru; Zolnikova, Nadezhda N., E-mail: altaisky@mx.iki.rssi.ru, E-mail: nzolnik@iki.rssi.ru; Kaputkina, Natalia E., E-mail: nataly@misis.ru

2016-03-07

We propose an implementation of quantum neural networks using an array of quantum dots with dipole-dipole interactions. We demonstrate that this implementation is both feasible and versatile by studying it within the framework of GaAs based quantum dot qubits coupled to a reservoir of acoustic phonons. Using numerically exact Feynman integral calculations, we have found that the quantum coherence in our neural networks survive for over a hundred ps even at liquid nitrogen temperatures (77 K), which is three orders of magnitude higher than current implementations, which are based on SQUID-based systems operating at temperatures in the mK range.

Decrement of uterine myometrial burst duration as a correlate to active labor: a Hilbert phase approach.

PubMed

Govindan, Rathinaswamy B; Vairavan, Srinivasan; Furdea, Adrian; Murphy, Pam; Preissl, Hubert; Eswaran, Hari

2010-01-01

We propose a novel approach based on Hilbert phase to identify the burst in the uterine myometrial activity. We apply this approach to 24 serial magnetomyographic signals recorded from four pregnant women using a 151 SQUID array system. The bursts identified with this approach are evaluated for duration and are correlated with the gestational age. In all four subjects, we find a decrease in the duration of burst as the subject approaches active labor. As was shown in animal studies, this result indicates a faster conduction time between the muscle cells which activate a larger number of muscle units in a synchronous manner.

Breadboard linear array scan imager using LSI solid-state technology

NASA Technical Reports Server (NTRS)

Tracy, R. A.; Brennan, J. A.; Frankel, D. G.; Noll, R. E.

1976-01-01

The performance of large scale integration photodiode arrays in a linear array scan (pushbroom) breadboard was evaluated for application to multispectral remote sensing of the earth's resources. The technical approach, implementation, and test results of the program are described. Several self scanned linear array visible photodetector focal plane arrays were fabricated and evaluated in an optical bench configuration. A 1728-detector array operating in four bands (0.5 - 1.1 micrometer) was evaluated for noise, spectral response, dynamic range, crosstalk, MTF, noise equivalent irradiance, linearity, and image quality. Other results include image artifact data, temporal characteristics, radiometric accuracy, calibration experience, chip alignment, and array fabrication experience. Special studies and experimentation were included in long array fabrication and real-time image processing for low-cost ground stations, including the use of computer image processing. High quality images were produced and all objectives of the program were attained.

System and method for 100% moisture and basis weight measurement of moving paper

DOEpatents

Hernandez, Jose E.; Koo, Jackson C.

2002-01-01

A system for characterizing a set of properties for a moving substance are disclosed. The system includes: a first near-infrared linear array; a second near-infrared linear array; a first filter transparent to a first absorption wavelength emitted by the moving substance and juxtaposed between the substance and the first array; a second filter blocking the first absorption wavelength emitted by the moving substance and juxtaposed between the substance and the second array; and a computational device for characterizing data from the arrays into information on a property of the substance. The method includes the steps of: filtering out a first absorption wavelength emitted by a substance; monitoring the first absorption wavelength with a first near-infrared linear array; blocking the first wavelength from reaching a second near-infrared linear array; and characterizing data from the arrays into information on a property of the substance.

Squid-derived chitin oligosaccharides are a chemotactic signal during colonization by Vibrio fischeri.

PubMed

Mandel, Mark J; Schaefer, Amy L; Brennan, Caitlin A; Heath-Heckman, Elizabeth A C; Deloney-Marino, Cindy R; McFall-Ngai, Margaret J; Ruby, Edward G

2012-07-01

Chitin, a polymer of N-acetylglucosamine (GlcNAc), is noted as the second most abundant biopolymer in nature. Chitin serves many functions for marine bacteria in the family Vibrionaceae ("vibrios"), in some instances providing a physical attachment site, inducing natural genetic competence, and serving as an attractant for chemotaxis. The marine luminous bacterium Vibrio fischeri is the specific symbiont in the light-emitting organ of the Hawaiian bobtail squid, Euprymna scolopes. The bacterium provides the squid with luminescence that the animal uses in an antipredatory defense, while the squid supports the symbiont's nutritional requirements. V. fischeri cells are harvested from seawater during each host generation, and V. fischeri is the only species that can complete this process in nature. Furthermore, chitin is located in squid hemocytes and plays a nutritional role in the symbiosis. We demonstrate here that chitin oligosaccharides produced by the squid host serve as a chemotactic signal for colonizing bacteria. V. fischeri uses the gradient of host chitin to enter the squid light organ duct and colonize the animal. We provide evidence that chitin serves a novel function in an animal-bacterial mutualism, as an animal-produced bacterium-attracting synomone.

Magnetoencephalography with a Cs-based high-sensitivity compact atomic magnetometer

NASA Astrophysics Data System (ADS)

Sheng, Jingwei; Wan, Shuangai; Sun, Yifan; Dou, Rongshe; Guo, Yuhao; Wei, Kequan; He, Kaiyan; Qin, Jie; Gao, Jia-Hong

2017-09-01

In recent years, substantial progress has been made in developing a new generation of magnetoencephalography (MEG) with a spin-exchange relaxation free (SERF)-based atomic magnetometer (AM). An AM employs alkali atoms to detect weak magnetic fields. A compact AM array with high sensitivity is crucial to the design; however, most proposed compact AMs are potassium (K)- or rubidium (Rb)-based with single beam configurations. In the present study, a pump-probe two beam configuration with a Cesium (Cs)-based AM (Cs-AM) is introduced to detect human neuronal magnetic fields. The length of the vapor cell is 4 mm, which can fully satisfy the need of designing a compact sensor array. Compared with state-of-the-art compact AMs, our new Cs-AM has two advantages. First, it can be operated in a SERF regime, requiring much lower heating temperature, which benefits the sensor with a closer distance to scalp due to ease of thermal insulation and less electric heating noise interference. Second, the two-beam configuration in the design can achieve higher sensitivity. It is free of magnetic modulation, which is necessary in one-beam AMs; however, such modulation may cause other interference in multi-channel circumstances. In the frequency band between 10 Hz and 30 Hz, the noise level of the proposed Cs-AM is approximately 10 f T/Hz1/2, which is comparable with state-of-the-art K- or Rb-based compact AMs. The performance of the Cs-AM was verified by measuring human auditory evoked fields (AEFs) in reference to commercial superconducting quantum interference device (SQUID) channels. By using a Cs-AM, we observed a clear peak in AEFs around 100 ms (M100) with a much larger amplitude compared with that of a SQUID, and the temporal profiles of the two devices were in good agreement. The results indicate the possibility of using the compact Cs-AM for MEG recordings, and the current Cs-AM has the potential to be designed for multi-sensor arrays and gradiometers for future neuroscience studies.

High resolution measurements of the Sunyaev-Zel'dovich Effect in galaxy clusters at 90 GHz

NASA Astrophysics Data System (ADS)

Young, Alexander H.

The MUltiplexed SQUID/TES Array at Ninety GHz (MUSTANG) is a 64-pixel array of transition-edge sensor (TES) bolometers built at the University of Pennsylvania (UPenn) for the Green Bank Telescope (GBT) in collaboration with a number of universities and government agencies such as NASA-GSFC, NRAO, and NIST. MUSTANG carried out observations between 2008 and 2013 and will soon be replaced by a new receiver (MUSTANG-1.5). MUSTANG-1.5 is a 223-pixel array of feedhorn-coupled polarimeters, which are read out with a novel microwave SQUID multiplexer. MUSTANG-1.5 offers many advantages over MUSTANG including more stable cryogenics, a larger field of view (5.5' compared to 42" for MUSTANG), and a significant improvement in sensitivity. These capabilities enable a far more comprehensive observing program. MUSTANG is aimed at measuring the distortion in the Cosmic Microwave Background (CMB) spectrum that arises due to the Sunyaev-Zel'dovich Effect (SZE). The SZE is the inverse Compton-scattering of CMB photons as they pass through the dense plasma in clusters of galaxies. The SZE is a nearly redshift-independent, complementary probe of the ICM to X-ray emission and combined analyses of both data sets provide a better understanding of astrophysical phenomena such as shocks, cold fronts, and Active Galactic Nucleus (AGN) outbursts. Understanding how substructure, especially in merging clusters, affects the scaling between SZE flux and total cluster mass is essential to placing tight constraints on cosmological parameters with SZE surveys. In this thesis, I present some of the last ever observations carried out by MUSTANG, which are centered on two massive galaxy clusters, MACS J0647.7+7015 and MACS J1206.2-0847. I discuss a model-fitting technique that has been used to quantitatively compare MUSTANG and lower resolution SZE data from Bolocam to study ICM pressure profiles. I report on the design, commissioning, and current status of MUSTANG-1.5 including the detectors, cryogenics, optics, and the microwave multiplexing readout electronics. Finally, I present early characterization of the cryogenics and readout electronics as the instrument nears deployment-readiness and discuss plans for the early science program.

Size increment of jumbo flying squid Dosidicus gigas mature females in Peruvian waters, 1989-2004

NASA Astrophysics Data System (ADS)

Argüelles, Juan; Tafur, Ricardo; Taipe, Anatolio; Villegas, Piero; Keyl, Friedeman; Dominguez, Noel; Salazar, Martín

2008-10-01

Changes in population structure of the jumbo flying squid Dosidicus gigas in Peruvian waters were studied based on size-at-maturity from 1989 to 2004. From 1989 to 1999, mature squid belonging to the medium-sized group prevailed, but from 2001 on, mature squids were larger. This change is not related to the changes in sea surface temperature and we hypothesized that it was caused by the population increase of mesopelagic fishes as prey.

Molecular identification of anisakid nematodes third stage larvae isolated from common squid ( Todarodes pacificus) in Korea

NASA Astrophysics Data System (ADS)

Setyobudi, Eko; Jeon, Chan-Hyeok; Choi, Kwangho; Lee, Sung Il; Lee, Chung Il; Kim, Jeong-Ho

2013-06-01

The occurrence of Genus Anisakis nematode larvae in marine fishes and cephalopods is epidemiologically important because Anisakis simplex larval stage can cause a clinical disease in humans when infected hosts are consumed raw. Common squid ( Todarodes pacificus) from Korean waters were investigated for anisakid nematodes infection during 2009˜2011. In total, 1,556 larvae were collected from 615 common squids and 732 of them were subsequently identified by PCR-RFLP analysis of ITS rDNA. Depending on the sampling locations, the nematode larvae from common squid showed different prevalence, intensity and species distribution. A high prevalence (P) and mean intensity (MI) of infection were observed in the Yellow Sea (n = 250, P = 86.0%, MI = 5.99 larvae/host) and the southern sea of Korea (n = 126, P = 57.1%, MI = 3.36 larvae/host). Anisakis pegreffii was dominantly found in common squid from the southern sea (127/ 140, 90.7%) and the Yellow Sea (561/565, 98.9%). In contrast, the P and MI of infection were relatively low in the East Sea (n = 239, P = 8.37%, MI = 1.25 larvae/host). A. pegreffii was not found from the East Sea and 52.0% (13/25) of the nematodes were identified as A. simplex. Most of them were found in the body cavity or digestive tract of common squid, which are rarely consumed raw by humans. Considering the differenences in anisakid nematode species distribution and their microhabitat in common squid, it remains unclear whether common squid plays an important role in the epidemiology of human anisakis infection in Korea. Further extensive identification of anisakid nematodes in common squid, with geographical and seasonal information will be necessary.

High-T(c) squid application in medicine and geophysics

NASA Technical Reports Server (NTRS)

Polushkin, V. N.; Uchaikin, S. V.; Vasiliev, B. V.

1991-01-01

In our laboratory of high-T(sub c), a one-hole squid was built from Y1Ba2Cu3O(7-x) ceramics obtained by a standard procedure of solid state reaction. The ceramics with critical current density J(sub c) is greater than 100 A/sq cm was selected. In the middle of a 10 x 10 x 2 mm ceramics pellet, a 0.8 mm hole was drilled in which the superconducting loop of the squid was located. Between the hole and the edge of the pellet, a cut was mechanically filed out with a bridge inside it connecting the superconducting ring. A scheme of the magnetometer is presented. The resonant frequency shift of the tank circuit, the connection of the squid with this circuit, and the squid inductance are evaluated. One of the most interesting fields of the squid-based magnetometer application is biomagnetism, particularly, the human heart magnetocardiogram measuring. The low-temperature squids were used in this area and many interesting and important scientific results have been obtained. The observations have shown that the main noise contribution was not due to the squid but to the Earth's magnetic field variations, industrial inductions, and mainly to the vibrations caused by liquid nitrogen boiling and by vibrations of the box. Further attempts are needed to reduce the magnetic noise inductions. Nevertheless, the estimations promise the maximum signal/noise relation of the high-T(sub c) squid-magnetocardiometer to be not less than 10:1 in a bandwidth of 60 Hz. Apparently, such resolution would be enough not only for steady cardiogram reading but even for thin structure investigation at average technique application.

High-T(sub c) squid application in medicine and geophysics

NASA Technical Reports Server (NTRS)

Polushkin, V. N.; Uchaikin, S. V.; Vasiliev, B. V.

1990-01-01

In the Laboratory a high-T(sub c) one-hole squid was built from Y1Ba2Cu3O(7-x) ceramics obtained by a standard procedure of solid state reaction. The ceramics with critical current density J(sub c) is greater than 100 A/sq cm was selected. In the middle of 10 x 10 x 2 mm ceramics pellet a 0.8 mm hole was drilled in which superconducting loop of the squid was located. Between the hole and the edge of the pellet a cut was mechanically filed out with a bridge inside it connecting the superconducting ring. A scheme of the magnetometer is presented. The resonant frequency shift of the tank circuit, the connection of the squid with this circuit, and the squid inductance are evaluated. One of the most interesting fields of the squid-based magnetometer application is biomagnetism, particularly, the human heart magnetocardiogram measuring. The low-temperature squids were used in this area and many interesting and important scientific results have been obtained. The observations have shown that the main noise contribution was not due to the squid but to the Earth's magnetic field variations, industrial inductions, and mainly to the vibrations caused by liquid nitrogen boiling and by vibrations of the box. Further attempts are needed to reduce the magnetic noise inductions. Nevertheless, the estimations promise the maximum signal/noise relation of the high-T(sub c) squid-magnetocardiometer to be not less than 10:1 in a bandwidth of 60 Hz. Apparently, such resolution would be enough not only for steady cardiogram reading but even for thin structure investigation at average technique application.

High-performance dc SQUIDs with submicrometer niobium Josephson junctions

NASA Astrophysics Data System (ADS)

de Waal, V. J.; Klapwijk, T. M.; van den Hamer, P.

1983-11-01

We report on the fabrication and performance of low-noise, all-niobium, thin-film planar dc SQUIDs with submicrometer Josephson junctions. The junctions are evaporated obliquely through a metal shadow evaporation mask, which is made using optical lithography with 0.5 µm tolerance. The Josephson junction barrier is formed by evaporating a thin silicon film and with a subsequent oxidation in a glow discharge. The junction parameters can be reproduced within a factor of two. Typical critical currents of the SQUIDs are about 3 µA and the resistances are about 100 Ω. With SQUIDs having an inductance of 1 nH the voltage modulation is at least 60 µV. An intrinsic energy resolution of 4×10-32 J/Hz has been reached. The SQUIDs are coupled to wire-wound input coils or with thin-film input coils. The thin-film input coil consists of a niobium spiral of 20 turns on a separate substrate. In both cases the coil is glued onto a 2-nH SQUID with a coupling efficiency of at least 0.5. Referred to the thin-film input coil, the best coupled energy resolution achieved is 1.2×10-30 J/Hz measured in a flux-locked loop at frequencies above 10 Hz. As far as we know, this is the best figure achieved with an all-refractory-metal thin-film SQUID. The fabrication technique used is suited for making circuits with SQUID and pickup coil on the same substrate. We describe a compact, planar, first-order gradiometer integrated with a SQUID on a single substrate. The gradient noise of this device is 3×10-12 T m-1. The gradiometer has a size of 12 mm×17 mm, is simple to fabricate, and is suitable for biomedical applications.

Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation, the environment, and fisheries

NASA Astrophysics Data System (ADS)

Neira, Sergio; Arancibia, Hugo

2013-10-01

We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978-2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.

Characterization of the Bacterial Diversity in Indo-West Pacific Loliginid and Sepiolid Squid Light Organs

PubMed Central

Guerrero-Ferreira, Ricardo; Gorman, Clayton; Chavez, Alba A.; Willie, Shantell

2013-01-01

Loliginid and sepiolid squid light organs are known to host a variety of bacterial species from the family Vibrionaceae, yet little is known about the species diversity and characteristics among different host squids. Here we present a broad-ranging molecular and physiological analysis of the bacteria colonizing light organs in loliginid and sepiolid squids from various field locations of the Indo-West Pacific (Australia and Thailand). Our PCR-RFLP analysis, physiological characterization, carbon utilization profiling, and electron microscopy data indicate that loliginid squid in the Indo-West Pacific carry a consortium of bacterial species from the families Vibrionaceae and Photobacteriaceae. This research also confirms our previous report of the presence of Vibrio harveyi as a member of the bacterial population colonizing light organs in loliginid squid. pyrH sequence data were used to confirm isolate identity, and indicates that Vibrio and Photobacterium comprise most of the light organ colonizers of squids from Australia, confirming previous reports for Australian loliginid and sepiolid squids. In addition, combined phylogenetic analysis of PCR-RFLP and 16S rDNA data from Australian and Thai isolates associated both Photobacterium and Vibrio clades with both loliginid and sepiolid strains, providing support that geographical origin does not correlate with their relatedness. These results indicate that both loliginid and sepiolid squids demonstrate symbiont specificity (Vibrionaceae), but their distribution is more likely due to environmental factors that are present during the infection process. This study adds significantly to the growing evidence for complex and dynamic associations in nature and highlights the importance of exploring symbiotic relationships in which non-virulent strains of pathogenic Vibrio species could establish associations with marine invertebrates. PMID:22885637

Negative inductance SQUID qubit operating in a quantum regime

NASA Astrophysics Data System (ADS)

Liu, W. Y.; Su, F. F.; Xu, H. K.; Li, Z. Y.; Tian, Ye; Zhu, X. B.; Lu, Li; Han, Siyuan; Zhao, S. P.

2018-04-01

Two-junction SQUIDs with negative mutual inductance between their two arms, called nSQUIDs, have been proposed for significantly improving quantum information transfer but their quantum nature has not been experimentally demonstrated. We have designed, fabricated, and characterized superconducting nSQUID qubits. Our results provide clear evidence of the quantum coherence of the device, whose properties are well described by theoretical calculations using parameters determined from spectroscopic measurement. In addition to their future application for fast quantum information transfer, the nSQUID qubits exhibit rich characteristics in their tunable two-dimensional (2D) potentials, energy levels, wave function symmetries, and dipole matrix elements, which are essential to the study of a wide variety of macroscopic quantum phenomena such as tunneling in 2D potential landscapes.

Novel Polymers Containing Metal Ligands in the Side Chain

DTIC Science & Technology

2012-10-01

10 2011): 0. doi: 10.1021/bm2010142 2012/10/01 15:35:02 10 Jun Cui, Melissa A. Lackey, Ahmad E. Madkour , Erika M. Saffer, David M. Griffin, Surita R...values for the linear fits are around 0.98. [M] denotes the monomer concentration. M- H measurement. If the RTF behavior of the previously...magnetization as a function of the applied field (M- H ) was measured at room temperature by a superconducting quantum interference device (SQUID) for all of

Experimental Studies of Josephson Effect

DTIC Science & Technology

1990-09-06

to test predictions that macroscopic variables, such as the flux through a SQUID loop, display quantum mechanical properties such as tunneling and...approximately Oo/L as flux quanta enter the loop. In the Josephson junctions used here are lead-alloy tunnel junc- linear region, for I, <<J, the rate...magnetometer. The junctions ln(F)-AU/kT+In(f/2z). (3) used were nominal I x I pm 2 Nb/AI2O3/Nb tunnel junc- As Fig. 3 shows, the observed dependence is in

Effect of thermal processing and canning on cadmium and lead levels in California market squid: the role of metallothioneins.

PubMed

Galitsopoulou, A; Georgantelis, D; Kontominas, M G

2013-01-01

The effects of two common seafood preparation practices (roasting and industrial canning) on the heavy metal content--cadmium (Cd) and lead (Pb)--of various tissues of California market squid were studied. Emphasis was placed on the role of metallothioneins (MT) in Cd and Pb behaviour during processing. Cd and Pb analysis was conducted by a Zeeman GTA-AAS atomic absorption spectrometry system; MT analysis was performed by a mercury saturation assay. Results showed that Cd levels in the mantle and whole squid were considerably affected by both processing practices, reaching a 240% increase in mantle and a 40% increase in whole squid. Interestingly, Cd behaviour was associated with MT changes during squid processing. On the other hand, Pb content was not affected from either processing or associated with MT content in the raw or processed squid. Therefore, processing operations may affect Cd and Pb content differently due to the specific metal bioaccumulation and chemical features of each heavy metal type.

Aperture effects in squid jet propulsion.

PubMed

Staaf, Danna J; Gilly, William F; Denny, Mark W

2014-05-01

Squid are the largest jet propellers in nature as adults, but as paralarvae they are some of the smallest, faced with the inherent inefficiency of jet propulsion at a low Reynolds number. In this study we describe the behavior and kinematics of locomotion in 1 mm paralarvae of Dosidicus gigas, the smallest squid yet studied. They swim with hop-and-sink behavior and can engage in fast jets by reducing the size of the mantle aperture during the contraction phase of a jetting cycle. We go on to explore the general effects of a variable mantle and funnel aperture in a theoretical model of jet propulsion scaled from the smallest (1 mm mantle length) to the largest (3 m) squid. Aperture reduction during mantle contraction increases propulsive efficiency at all squid sizes, although 1 mm squid still suffer from low efficiency (20%) because of a limited speed of contraction. Efficiency increases to a peak of 40% for 1 cm squid, then slowly declines. Squid larger than 6 cm must either reduce contraction speed or increase aperture size to maintain stress within maximal muscle tolerance. Ecological pressure to maintain maximum velocity may lead them to increase aperture size, which reduces efficiency. This effect might be ameliorated by nonaxial flow during the refill phase of the cycle. Our model's predictions highlight areas for future empirical work, and emphasize the existence of complex behavioral options for maximizing efficiency at both very small and large sizes.

Inductance analysis of superconducting quantum interference devices with 3D nano-bridge junctions

NASA Astrophysics Data System (ADS)

Wang, Hao; Yang, Ruoting; Li, Guanqun; Wu, Long; Liu, Xiaoyu; Chen, Lei; Ren, Jie; Wang, Zhen

2018-05-01

Superconducting quantum interference devices (SQUIDs) with 3D nano-bridge junctions can be miniaturized into nano-SQUIDs that are able to sense a few spins in a large magnetic field. Among all device parameters, the inductance is key to the performance of SQUIDs with 3D nano-bridge junctions. Here, we measured the critical-current magnetic flux modulation curves of 12 devices with three design types using a current strip-line directly coupled to the SQUID loop. A best flux modulation depth of 71% was achieved for our 3D Nb SQUID. From the modulation curves, we extracted the inductance values of the current stripe-line in each design and compared them with the corresponding simulation results of InductEX. In this way, London penetration depths of 110 and 420 nm were determined for our Nb (niobium) and NbN (niobium nitride) films, respectively. Furthermore, we showed that inductances of 11 and 119 pH for Nb and NbN 3D nano-bridge junctions, respectively, dominated the total inductance of our SQUID loops which are 23 pH for Nb and 255 pH for NbN. A screening parameter being equal to one suggests optimal critical currents of 89.6 and 8.1 μA for Nb and NbN SQUIDs, respectively. Additionally, intrinsic flux noise of 110 ± 40 nΦ0/(Hz)1/2 is calculated for the Nb SQUIDs with 3D nano-bridge junctions by Langevin simulation.

Multistatic Array Sampling Scheme for Fast Near-Field Image Reconstruction

DTIC Science & Technology

2016-01-01

reconstruction. The array topology samples the scene on a regular grid of phase centers, using a tiling of Boundary Arrays (BAs). Following a simple correction...hardware. Fig. 1 depicts the multistatic array topology. As seen, the topology is a tiled arrangement of Boundary Arrays (BAs). The BA is a well-known...sparse array layout comprised of two linear transmit arrays, and two linear receive arrays [6]. A slightly different tiled arrangement of BAs was used

Noise Modeling From Conductive Shields Using Kirchhoff Equations.

PubMed

Sandin, Henrik J; Volegov, Petr L; Espy, Michelle A; Matlashov, Andrei N; Savukov, Igor M; Schultz, Larry J

2010-10-09

Progress in the development of high-sensitivity magnetic-field measurements has stimulated interest in understanding the magnetic noise of conductive materials, especially of magnetic shields based on high-permeability materials and/or high-conductivity materials. For example, SQUIDs and atomic magnetometers have been used in many experiments with mu-metal shields, and additionally SQUID systems frequently have radio frequency shielding based on thin conductive materials. Typical existing approaches to modeling noise only work with simple shield and sensor geometries while common experimental setups today consist of multiple sensor systems with complex shield geometries. With complex sensor arrays used in, for example, MEG and Ultra Low Field MRI studies, knowledge of the noise correlation between sensors is as important as knowledge of the noise itself. This is crucial for incorporating efficient noise cancelation schemes for the system. We developed an approach that allows us to calculate the Johnson noise for arbitrary shaped shields and multiple sensor systems. The approach is efficient enough to be able to run on a single PC system and return results on a minute scale. With a multiple sensor system our approach calculates not only the noise for each sensor but also the noise correlation matrix between sensors. Here we will show how the algorithm can be implemented.

77 FR 22678 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-17

.... 110707371-2136-02] RIN 0648- XB145 Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the Trimester 1 Longfin Squid Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION...

Development and Evaluation of an Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System for Detection, Characterization and Mapping of Unexploded Ordnance

DTIC Science & Technology

2008-08-01

Figure 17: USGS Helmholtz coils with SQUID and fluxgate magnetometers installed. 22 Figure 18: Plot of SQUID and fluxgate data from a rotating... fluxgate magnetometer , each sensor measures flux in only one direction. Combinations of SQUID sensor elements are arranged in various configurations...than the absolute field value the way that a fluxgate magnetometer would do. If the SQUID is shut down or loses lock, it has no way to relate the new

Fabrication of Superconducting Quantum Interference Device Magnetometers on a Glass Epoxy Polyimide Resin Substrate with Copper Terminals

NASA Astrophysics Data System (ADS)

Kawai, Jun; Kawabata, Miki; Oyama, Daisuke; Uehara, Gen

We have developed fabrication technique of superconducting quantum interference device (SQUID) magnetometers based on Nb/AlAlOx/Nb junctions directly on a glass epoxy polyimide resin substrate, which has copper terminals embedded in advance. The advantage of this method is that no additional substrate and wirebonds are needed for assembly. Compared to conventional SQUID magnetometers, which are assembled with a SQUID chip fabricated on a Si substrate and wirebonding technique, low risk of disconnection can be expected. A directly-coupled multi-loop SQUID magnetometer fabricated with this method has as good noise performance as a SQUID magnetometer with the same design fabricated on a Si wafer. The magnetometer sustained its performance through thermal cycle test 13 times so far.

Natural mortality estimation and rational exploitation of purpleback flying squid Sthenoteuthis oualaniensis in the southern South China Sea

NASA Astrophysics Data System (ADS)

Wang, Xuehui; Qiu, Yongsong; Zhang, Peng; Du, Feiyan

2017-07-01

Based on the biological data of purpleback flying squid ( Sthenoteuthis oualaniensis) collected by light falling-net in the southern South China Sea (SCS) during September to October 2012 and March to April 2013, growth and mortality of `Medium' and `Dwarf' forms of squid are derived using the Powell-Wetherall, ELEFAN methods and length-converted catch curves (FiSAT package). Given a lack of commercial exploitation, we assume total mortality to be due entirely to natural mortality. We estimate these squid have fast growth, with growth coefficients ( k) ranging from 1.42 to 2.39, and high natural mortality ( M), with estimates ranging from 1.61 to 2.92. To sustainably exploit these squid stocks, yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model. We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture, with an optimal fishing mortality >3.0, with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels. On the basis of our analyses and estimates of stock biomass, we believe considerable potential exists to expand the squid fishery into the open SCS, relieving fishing pressure on coastal waters.

Superconducting Quantum Interferometers for Nondestructive Evaluation

PubMed Central

Kostyurina, E. A.; Kalashnikov, K. V.; Maslennikov, Yu. V.; Koshelets, V. P.

2017-01-01

We review stationary and mobile systems that are used for the nondestructive evaluation of room temperature objects and are based on superconducting quantum interference devices (SQUIDs). The systems are optimized for samples whose dimensions are between 10 micrometers and several meters. Stray magnetic fields from small samples (10 µm–10 cm) are studied using a SQUID microscope equipped with a magnetic flux antenna, which is fed through the walls of liquid nitrogen cryostat and a hole in the SQUID’s pick-up loop and returned sidewards from the SQUID back to the sample. The SQUID microscope does not disturb the magnetization of the sample during image recording due to the decoupling of the magnetic flux antenna from the modulation and feedback coil. For larger samples, we use a hand-held mobile liquid nitrogen minicryostat with a first order planar gradiometric SQUID sensor. Low-Tc DC SQUID systems that are designed for NDE measurements of bio-objects are able to operate with sufficient resolution in a magnetically unshielded environment. High-Tc DC SQUID magnetometers that are operated in a magnetic shield demonstrate a magnetic field resolution of ~4 fT/√Hz at 77 K. This sensitivity is improved to ~2 fT/√Hz at 77 K by using a soft magnetic flux antenna. PMID:29210980

Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the California Current.

PubMed

Becker, Kaylyn N; Warren, Joseph D

2015-05-01

Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the California Current ecosystem were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton.

Squid rocket science: How squid launch into air

NASA Astrophysics Data System (ADS)

O'Dor, Ron; Stewart, Julia; Gilly, William; Payne, John; Borges, Teresa Cerveira; Thys, Tierney

2013-10-01

Squid not only swim, they can also fly like rockets, accelerating through the air by forcefully expelling water out of their mantles. Using available lab and field data from four squid species, Sthenoteuthis pteropus, Dosidicus gigas, Illex illecebrosus and Loligo opalescens, including sixteen remarkable photographs of flying S. pteropus off the coast of Brazil, we compared the cost of transport in both water and air and discussed methods of maximizing power output through funnel and mantle constriction. Additionally we found that fin flaps develop at approximately the same size range as flight behaviors in these squids, consistent with previous hypotheses that flaps could function as ailerons whilst aloft. S. pteropus acceleration in air (265 body lengths [BL]/s2; 24.5m/s2) was found to exceed that in water (79BL/s2) three-fold based on estimated mantle length from still photos. Velocities in air (37BL/s; 3.4m/s) exceed those in water (11BL/s) almost four-fold. Given the obvious advantages of this extreme mode of transport, squid flight may in fact be more common than previously thought and potentially employed to reduce migration cost in addition to predation avoidance. Clearly squid flight, the role of fin flaps and funnel, and the energetic benefits are worthy of extended investigation.

Identification of four squid species by quantitative real-time polymerase chain reaction.

PubMed

Ye, Jian; Feng, Junli; Liu, Shasha; Zhang, Yanping; Jiang, Xiaona; Dai, Zhiyuan

2016-02-01

Squids are distributed worldwide, including many species of commercial importance, and they are often made into varieties of flavor foods. The rapid identification methods for squid species especially their processed products, however, have not been well developed. In this study, quantitative real-time PCR (qPCR) systems based on specific primers and TaqMan probes have been established for rapid and accurate identification of four common squid species (Ommastrephes bartramii, Dosidicus gigas, Illex argentinus, Todarodes pacificus) in Chinese domestic market. After analyzing mitochondrial genes reported in GenBank, the mitochondrial cytochrome b (Cytb) gene was selected for O. bartramii detection, cytochrome c oxidase subunit I (COI) gene for D. gigas and T. Pacificus detection, ATPase subunit 6 (ATPase 6) gene for I. Argentinus detection, and 12S ribosomal RNA (12S rDNA) gene for designing Ommastrephidae-specific primers and probe. As a result, all the TaqMan systems are of good performance, and efficiency of each reaction was calculated by making standard curves. This method could detect target species either in single or mixed squid specimen, and it was applied to identify 12 squid processed products successfully. Thus, it would play an important role in fulfilling labeling regulations and squid fishery control. Copyright © 2016 Elsevier Ltd. All rights reserved.

Opportunistic acoustic recordings of (potential) orangeback flying squid Sthenoteuthis pteropus in the Central Eastern Atlantic

NASA Astrophysics Data System (ADS)

Peña, Marian; Villanueva, Roger; Escánez, Alejandro; Ariza, Alejandro

2018-03-01

Squids are fast swimmers that are difficult to catch by nets and to record with echosounders in the open ocean. A rare detection of orangeback flying squid Sthenoteuthis pteropus in the Central Eastern Atlantic Ocean off the coast of Senegal was accomplished during the MAFIA oceanographic survey carried out between Brazil and the Canary Islands in April 2015. Although net sampling did not yield any subadult or adult individuals, dozens were visually detected from the vessel jumping out of the water at night and displaying their characteristic dorsal photophore patch. A few squids were caught with fishing lines and identified at the species level. The acoustic echograms revealed distinctive previously unobserved acoustic echotraces that seemed to be caused by those squids, which were the only new species detected at that station (over a bottom depth ranging from 4010 to 5215 m, between 10° 45‧ N 22° 41‧ W and 10° 53‧ N 22° 40‧ W). The acoustic response and swimming behaviour shown by those echotraces reinforced this hypothesis. The (potentially) squid recordings dove rapidly (0.19 m/s to 0.48 m/s) from around 10 m below the mesopelagic fish layer, which had migrated to the subsurface at night (35 m depth), to depths of 70-95 m, and swam upward, apparently attacking fish from below. The morning squid migration to deeper waters (250-300 m) was also recorded acoustically. Downward movements of squid swimming at speeds of 0.22 m/s were calculated from the echogram, while the mesopelagic migrating fish swam at 0.27 m/s reaching 250 m depth. Sv120 - Sv38 averaged 2.7 ± 3.2 dB for the squid echotraces while the mesopelagic layer showed values of -8.8 ± 0.9 dB. These ranges agreed with values in the literature and from theoretical models. This study provides more insight into the migrating behaviour of oceanic squids, a species group that is poorly represented in the acoustic literature due to challenges in studying them.

Extreme plasticity in life-history strategy allows a migratory predator (jumbo squid) to cope with a changing climate.

PubMed

Hoving, Henk-Jan T; Gilly, William F; Markaida, Unai; Benoit-Bird, Kelly J; -Brown, Zachary W; Daniel, Patrick; Field, John C; Parassenti, Liz; Liu, Bilin; Campos, Bernardita

2013-07-01

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1-1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño event in 2009-2010, was accompanied by a collapse of this fishery, and squid in the region showed major changes in the distribution and life-history strategy. Large squid abandoned seasonal coastal-shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Niño by tidal upwelling and a well-mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010 to 2012, small squid were abundant and matured at an unusually small mantle-length (<30 cm) and young age (approximately 6 months). Juvenile squid thus appeared to respond to El Niño with an alternative life-history trajectory in which gigantism and high fecundity in normally productive coastal-shelf habitats were traded for accelerated reproduction at small size in an offshore environment. Both small and large mature squid, were present in the Salsipuedes Basin during 2011, indicating that both life- history strategies can coexist. Hydro-acoustic data, reveal that squid biomass in this study area nearly doubled between 2010 and 2011, primarily due to a large increase in small squid that were not susceptible to the fishery. Such a climate-driven switch in size-at-maturity may allow D. gigas to rapidly adapt to and cope with El Niño. This ability is likely to be an important factor in conjunction with longerterm climate-change and the potential ecological impacts of this invasive predator on marine ecosystems. © 2013 Blackwell Publishing Ltd.

Relationships between morphometrical properties and the texture of an extrusion-expanded snack made from squid mantle (Dosidicus gigas).

PubMed

Valenzuela-Lagarda, José Luis; García-Armenta, Evangelina; Pacheco-Aguilar, Ramón; Gutiérrez-Dorado, Roberto; Mazorra-Manzano, Miguel Ángel; Lugo-Sánchez, María Elena; Muy-Rangel, María Dolores

2018-01-24

The giant squid (Dosidicus gigas) is a species of commercial interest as a source of protein, and it can be developed into ready-to-eat food products, including expanded extrusion snacks (EES). EES are prepared primarily from starch; however, adding animal protein increases the nutritional contents. The objective of this study was to evaluate the effect of the protein-carbohydrate interactions on the physical and morphological characteristics of an EES made of squid mantle and potato-corn flour. The independent variable was the squid mantle content (40, 60, 80, and 100%) and two controls (0 1  = 100% potato, 0 2  = 100% corn). The expansion rate (ER) of the sample is significantly minor (p < .5) when the squid mantle content increases ER = 2.0, 1.8 1.4 to 40, 60, and 80%, respectively. In samples with more protein, crispness and crunchiness were reduced, whereas the hardness increased. Digital imaging analysis indicated that the interaction between protein and starch causes significant morphometric changes to the fractal dimension (2.665-2.739) and lacunarity (0.61-1.29). The results showed that it is possible to incorporate up to 60% squid mantle to prepare EES that possess texture and morphometric characteristics competitive in reported studies with snacks usually incorporating flours, corn, and wheat in the formulations. The giant squid is a very attractive species because its meat has low caloric intake, high protein content, and is an important source of omega 3 fatty acids. Despite the desirable qualities of the squid meat its consumption is very low due to the low diffusion of the properties of its meat, acid, and ammoniacal flavor, rigid texture that requires prolonged cooking times and lack of alternatives of consumption. In Mexico, this type of squid is mainly destined for export as frozen mantle and products with little added value, which generates little economic benefit. Therefore, the results of this research may be of interest to the squid processing industry, which demands new forms of consumption of this marine species to increase their commercialization and added value. © 2018 Wiley Periodicals, Inc.

Conformal array design on arbitrary polygon surface with transformation optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Li, E-mail: dengl@bupt.edu.cn; Hong, Weijun, E-mail: hongwj@bupt.edu.cn; Zhu, Jianfeng

2016-06-15

A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

TES X-ray microcalorimeters for X-ray astronomy and material analysis

NASA Astrophysics Data System (ADS)

Mitsuda, Kazuhisa

2016-11-01

TES X-ray microcalorimeter arrays provide not only high-energy resolution (FWHM < 10eV) in X-ray spectroscopy but also imaging and high-counting-rate capabilities. They are very promising spectrometer for X-ray astronomy and material analysis. In this paper, we report our recent progress. For material analysis, we have fabricated 8 × 8 format array with a fast signal response ( 40 μs) and proved the energy resolution of 5.8 eV FWHM at 5.9 keV. We developed common biasing scheme to reduce number of wirings from room temperature to the cryogenic stage. From measurements using the newly-designed common-bias SQUID array amplifier chips, and from numerical simulations, we demonstrated that signal cross talks due to the common bias is enough small. For space applications, we are developing frequency-division signal multiplexing system. We have fabricated a baseband feedback system and demonstrated that the noise added by the feedback system is about 4 eV FWHM equivalent for 16 ch multiplexing system. The digital to analog converter (DAC) dominates the noise, and needs be reduced by a factor of four for future astronomy missions.

Multiple sensory modalities used by squid in successful predator evasion throughout ontogeny.

PubMed

York, Carly A; Bartol, Ian K; Krueger, Paul S

2016-09-15

Squid rely on multiple sensory systems for predator detection. In this study we examine the role of two sensory systems, the lateral line analogue and vision, in successful predator evasion throughout ontogeny. Squid Doryteuthis pealeii and Lolliguncula brevis were recorded using high-speed videography in the presence of natural predators under light and dark conditions with their lateral line analogue intact or ablated via a pharmacological technique. Paralarval squid showed reduced escape responses when ablated; however, no differences were found between light and dark conditions in non-ablated paralarvae, as was previously shown in juveniles and adults, indicating that the lateral line analogue is integral for predator detection early in life. However, vision does play a role in survival because ablated squid in dark conditions had lower levels of survival than all other treatments. Throughout ontogeny, squid oriented themselves anteriorly towards the oncoming predator, maximizing sensory input to the lateral line analogue system and providing better positioning for tail-first escape jetting, the preferred escape mode. Ablated juveniles and adults had lower response times, escape velocities and peak acceleration than non-ablated individuals, indicating that the lateral line analogue enables squid to respond quicker and with more powerful jets to a predator and maximize escape success. Our findings reveal that the lateral line analogue plays a role in predator detection and successful escape response at the earliest life stages, and continues to contribute to successful evasion by aiding visual cues in juvenile and adult squid. © 2016. Published by The Company of Biologists Ltd.

SQUID use for Geophysics: finding billions of dollars

NASA Astrophysics Data System (ADS)

Foley, Catherine

2014-03-01

Soon after their discovery, Jim Zimmerman saw the potential of using Superconducting Quantum Interference Devices, SQUIDs, for the study of Geophysics and undertook experiments to understand the magnetic phenomena of the Earth. However his early experiments were not successful. Nevertheless up to the early 1980's, some research effort in the use of SQUIDs for geophysics continued and many ideas of how you could use SQUIDs evolved. Their use was not adopted by the mining industry at that time for a range of reasons. The discovery of high temperature superconductors started a reinvigoration in the interest to use SQUIDs for mineral exploration. Several groups around the world worked with mining companies to develop both liquid helium and nitrogen cooled systems. The realisation of the achievable sensitivity that contributed to successful mineral discoveries and delineation led to real financial returns for miners. By the mid 2000's, SQUID systems for geophysics were finally being offered for sale by several start-up companies. This talk will tell the story of SQUID use in geophysics. It will start with the early work of the SQUID pioneers including that of Jim Zimmerman and John Clarke and will also cover the development since the early 1990's up to today of a number of magnetometers and gradiometers that have been successfully commercialised and used to create significant impact in the global resources industry. The talk will also cover some of the critical technical challenges that had to be overcome to succeed. It will focus mostly on magnetically unshielded systems used in the field although some laboratory-based systems will be discussed.

ZEUS-2: a second generation submillimeter grating spectrometer for exploring distant galaxies

NASA Astrophysics Data System (ADS)

Ferkinhoff, Carl; Nikola, Thomas; Parshley, Stephen C.; Stacey, Gordon J.; Irwin, Kent D.; Cho, Hsiao-Mei; Halpern, Mark

2010-07-01

ZEUS-2, the second generation (z)Redshift and Early Universe Spectrometer, like its predecessor is a moderate resolution (R~1000) long-slit, echelle grating spectrometer optimized for the detection of faint, broad lines from distant galaxies. It is designed for studying star-formation across cosmic time. ZEUS-2 employs three TES bolometer arrays (555 pixels total) to deliver simultaneous, multi-beam spectra in up to 4 submillimeter windows. The NIST Boulder-built arrays operate at ~100mK and are readout via SQUID multiplexers and the Multi-Channel Electronics from the University of British Columbia. The instrument is cooled via a pulse-tube cooler and two-stage ADR. Various filter configurations give ZEUS-2 access to 7 different telluric windows from 200 to 850 micron enabling the simultaneous mapping of lines from extended sources or the simultaneous detection of the 158 micron [CII] line and the [NII] 122 or 205 micron lines from z = 1-2 galaxies. ZEUS-2 is designed for use on the CSO, APEX and possibly JCMT.

Spiral wave chimera states in large populations of coupled chemical oscillators

NASA Astrophysics Data System (ADS)

Totz, Jan Frederik; Rode, Julian; Tinsley, Mark R.; Showalter, Kenneth; Engel, Harald

2018-03-01

The coexistence of coherent and incoherent dynamics in a population of identically coupled oscillators is known as a chimera state1,2. Discovered in 20023, this counterintuitive dynamical behaviour has inspired extensive theoretical and experimental activity4-15. The spiral wave chimera is a particularly remarkable chimera state, in which an ordered spiral wave rotates around a core consisting of asynchronous oscillators. Spiral wave chimeras were theoretically predicted in 200416 and numerically studied in a variety of systems17-23. Here, we report their experimental verification using large populations of nonlocally coupled Belousov-Zhabotinsky chemical oscillators10,18 in a two-dimensional array. We characterize previously unreported spatiotemporal dynamics, including erratic motion of the asynchronous spiral core, growth and splitting of the cores, as well as the transition from the chimera state to disordered behaviour. Spiral wave chimeras are likely to occur in other systems with long-range interactions, such as cortical tissues24, cilia carpets25, SQUID metamaterials26 and arrays of optomechanical oscillators9.

Restoring Low Sidelobe Antenna Patterns with Failed Elements in a Phased Array Antenna

DTIC Science & Technology

2016-02-01

optimum low sidelobes are demonstrated in several examples. Index Terms — Array signal processing, beams, linear algebra , phased arrays, shaped...represented by a linear combination of low sidelobe beamformers with no failed elements, ’s, in a neighborhood around under the constraint that the linear ...would expect that linear combinations of them in a neighborhood around would also have low sidelobes. The algorithms in this paper exploit this

50 CFR 648.124 - Scup commercial season and commercial fishery area restrictions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... vessels in the Southern Gear Restricted Area that are fishing for or in possession of the following non-exempt species: Longfin squid; black sea bass; and silver hake (whiting). (b) Northern Gear Restricted... are fishing for, or in possession of, the following non-exempt species: Longfin squid squid; black sea...

50 CFR 648.124 - Scup commercial season and commercial fishery area restrictions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... vessels in the Southern Gear Restricted Area that are fishing for or in possession of the following non-exempt species: Longfin squid; black sea bass; and silver hake (whiting). (b) Northern Gear Restricted... are fishing for, or in possession of, the following non-exempt species: Longfin squid squid; black sea...

50 CFR 648.124 - Scup commercial season and commercial fishery area restrictions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... vessels in the Southern Gear Restricted Area that are fishing for or in possession of the following non-exempt species: Longfin squid; black sea bass; and silver hake (whiting). (b) Northern Gear Restricted... are fishing for, or in possession of, the following non-exempt species: Longfin squid squid; black sea...

Non-destructive inspection using HTS SQUID on aluminum liner covered by CFRP

NASA Astrophysics Data System (ADS)

Hatsukade, Y.; Yotsugi, K.; Sakaguchi, Y.; Tanaka, S.

2007-10-01

An eddy-current-based SQUID non-destructive inspection (NDI) system to detect deep-lying cracks in multi-layer composite-Al vessels was developed taking advantage of the uncontested sensitivity of HTS-SQUID in low-frequency range. An HTS-SQUID gradiometer was mounted in a pulse tube cryocooler. A pair of differential coils with C-shaped ferrite cores was employed to induce an enhanced eddy current in an Al vessel wrapped in a carbon fiber reinforced plastic (CFRP) cover. Ellipsoidal dome-shaped Al liners containing through cracks, which were made by pressure cycle tests, in the CFRP covers with total thickness of 6 mm (CFPR 3 mm, and Al 3 mm) were inspected by the system. While inducing eddy currents in the vessels with excitation fields at 100 Hz or 7 kHz, the vessels were rotated under the HTS-SQUID. Above the cracks, anomalous signals due to the cracks were clearly detected at both frequencies. These results suggested the SQUID-NDI technique would be a possible candidate for inspection of high-pressure multi-layer composite-Al vessels.

Partial characterization of an effluent produced by cooking of Jumbo squid (Dosidicus gigas) mantle muscle.

PubMed

Rosas-Romero, Zaidy G; Ramirez-Suarez, Juan C; Pacheco-Aguilar, Ramón; Lugo-Sánchez, Maria E; Carvallo-Ruiz, Gisela; García-Sánchez, Guillermina

2010-01-01

Jumbo squid (Dosidicus gigas) mantle muscle was cooked simulating industrial procedures (95 degrees C x 25 min, 1.2:5 muscle:water ratio). The effluent produced was analyzed for chemical and biochemical oxygen demands (COD and BOD(5), respectively), proximate analysis, flavor-related compounds (free amino acids, nucleotides and carbohydrates) and SDS-PAGE. The COD and BOD(5) exhibited variation among samplings (N=3) (27.4-118.5 g O(2)/L for COD and 11.3-26.7 g O(2)/L for BOD(5)). The effluent consisted of 1% total solids, 75% of which represented crude protein. Sixty percent of the total free amino acid content, which imparts flavor in squid species, corresponded to glutamic acid, serine, glycine, arginine, alanine, leucine and lysine. The nucleotide concentration followed this order, Hx>ADP>AMP>ATP>IMP>HxR. The variation observed in the present work was probably due to physiological maturity differences among the squid specimens (i.e., juvenile versus mature). Solids present in squid cooking effluent could be recovered and potentially used as flavor ingredients in squid-analog production by the food industry.

Paleomagnetic Analysis Using SQUID Microscopy

NASA Technical Reports Server (NTRS)

Weiss, Benjamin P.; Lima, Eduardo A.; Fong, Luis E.; Baudenbacher, Franz J.

2007-01-01

Superconducting quantum interference device (SQUID) microscopes are a new generation of instruments that map magnetic fields with unprecedented spatial resolution and moment sensitivity. Unlike standard rock magnetometers, SQUID microscopes map magnetic fields rather than measuring magnetic moments such that the sample magnetization pattern must be retrieved from source model fits to the measured field data. In this paper, we presented the first direct comparison between paleomagnetic analyses on natural samples using joint measurements from SQUID microscopy and moment magnetometry. We demonstrated that in combination with apriori geologic and petrographic data, SQUID microscopy can accurately characterize the magnetization of lunar glass spherules and Hawaiian basalt. The bulk moment magnitude and direction of these samples inferred from inversions of SQUID microscopy data match direct measurements on the same samples using moment magnetometry. In addition, these inversions provide unique constraints on the magnetization distribution within the sample. These measurements are among the most sensitive and highest resolution quantitative paleomagnetic studies of natural remanent magnetization to date. We expect that this technique will be able to extend many other standard paleomagnetic techniques to previously inaccessible microscale samples.

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

PubMed Central

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-01-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field. PMID:26459874

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

NASA Astrophysics Data System (ADS)

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-10-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field.

Prospects on the application of HTS SQUID magnetometry to nondestructive evaluation (NDE)

NASA Astrophysics Data System (ADS)

Weinstock, H.

1993-04-01

In light of recent advances in the fabrication of low-noise HTS SQUIDs, a review is presented on the use of LTS SQUID magnetometry for nondestructive evaluation (NDE). Examples are given on applications relating to defects in steel, subsurface cracks in aircraft frames, and voids in non-metallic structures. HTS SQUIDs may make a significant difference in the acceptance of these applications because sensing coils will be closer to a sample under test, there will be greater instrument portability and the problem of bringing liquid helium to remote locations will be eliminated.

The Polarbear-2 and the Simons Array experiments

DOE PAGES

Suzuki, A.; Ade, P.; Akiba, Y.; ...

2016-01-06

Here, we present an overview of the design and status of the POLARBEAR-2 and the Simons Array experiments. POLARBEAR- 2 is a Cosmic Microwave Background polarimetry experiment which aims to characterize the arc-minute angular scale B-mode signal from weak gravitational lensing and search for the degree angular scale B-mode signal from inflationary gravitational waves. The receiver has a 365 mm diameter focal plane cooled to 270 milli-Kelvin. The focal plane is filled with 7,588 dichroic lenslet-antenna coupled polarization sensitive Transition Edge Sensor (TES) bolometric pixels that are sensitive to 95 GHz and 150 GHz bands simultaneously. The TES bolometers aremore » read-out by SQUIDs with 40 channel frequency domain multiplexing. Refractive optical elements are made with high purity alumina to achieve high optical throughput. The receiver is designed to achieve noise equivalent temperature of 5.8 µK CMB√s in each frequency band. POLARBEAR-2 will deploy in 2016 in the Atacama desert in Chile. The Simons Array is a project to further increase sensitivity by deploying three POLARBEAR-2 type receivers. The Simons Array will cover 95 GHz, 150 GHz and 220 GHz frequency bands for foreground control. The Simons Array will be able to constrain tensor-to-scalar ratio and sum of neutrino masses to σ(r) = 6×10 $-$3 at r = 0.1 and Σm ν(σ = 1) to 40 meV.« less

OpenSQUID: A Flexible Open-Source Software Framework for the Control of SQUID Electronics

DOE PAGES

Jaeckel, Felix T.; Lafler, Randy J.; Boyd, S. T. P.

2013-02-06

We report commercially available computer-controlled SQUID electronics are usually delivered with software providing a basic user interface for adjustment of SQUID tuning parameters, such as bias current, flux offset, and feedback loop settings. However, in a research context it would often be useful to be able to modify this code and/or to have full control over all these parameters from researcher-written software. In the case of the STAR Cryoelectronics PCI/PFL family of SQUID control electronics, the supplied software contains modules for automatic tuning and noise characterization, but does not provide an interface for user code. On the other hand, themore » Magnicon SQUIDViewer software package includes a public application programming interface (API), but lacks auto-tuning and noise characterization features. To overcome these and other limitations, we are developing an "open-source" framework for controlling SQUID electronics which should provide maximal interoperability with user software, a unified user interface for electronics from different manufacturers, and a flexible platform for the rapid development of customized SQUID auto-tuning and other advanced features. Finally, we have completed a first implementation for the STAR Cryoelectronics hardware and have made the source code for this ongoing project available to the research community on SourceForge (http://opensquid.sourceforge.net) under the GNU public license.« less

[Biochemistry and functional characterization of squid mantle meat (Dosidicus gigas)].

PubMed

Abugoch, L; Guarda, A; María Pérez, L; Isabel Donghi, M

2000-12-01

A study for the characterization of frozen giant squid mantle (meat) protein stored at -25 degrees C for 8 month was started. In the present research, the following functional properties were investigate: emulsifying, water holding and gel forming capacities. Optimal conditions for the separation and differentiation of miofibrillar and sarcoplasmatic proteins were also studied. It was found that the unfrozen giant squid mantle meat es capable of emulifying 2.817,4 g of oil/g of protein and holding capacity was 3.64 g of water/g of protein. Related to the gel forming capacity, it was not obtain, probably due to excessive storage of the meat. With regard to miofibrilar protein obtention of the squid mantle meat, it was found that two low ionic strength washings (I = 0.05), the sarcoplasmic proteins were practically eliminated from the protein matrix. The differentiation of miofibrilar and sarcoplasmatic proteins was obtained by PAGE-SDS of the squid mantle meat extracted at two different ionic strength (I = 0.05 and I = 0.5). This work demonstrates that the giant squid mantle protein has a high emulsifying and water holding capacity, and it can be used, as a raw material, for the improvement of sausage products. About the gelling products, more studies will be necessary with fresh squid mantle meat to conclude about this functional property.

Structural elements of the signal propagation pathway in squid rhodopsin and bovine rhodopsin.

PubMed

Sugihara, Minoru; Fujibuchi, Wataru; Suwa, Makiko

2011-05-19

Squid and bovine rhodopsins are G-protein coupled receptors (GPCRs) that activate Gq- and Gt-type G-proteins, respectively. To understand the structural elements of the signal propagation pathway, we performed molecular dynamics (MD) simulations of squid and bovine rhodopsins plus a detailed sequence analysis of class A GPCRs. The computations indicate that although the geometry of the retinal is similar in bovine and squid rhodopsins, the important interhelical hydrogen bond networks are different. In squid rhodopsin, an extended hydrogen bond network that spans ∼13 Å to Tyr315 on the cytoplasmic site is present regardless of the protonation state of Asp80. In contrast, the extended hydrogen bond network is interrupted at Tyr306 in bovine rhodopsin. Those differences in the hydrogen bond network may play significant functional roles in the signal propagation from the retinal binding site to the cytoplasmic site, including transmembrane helix (TM) 6 to which the G-protein binds. The MD calculations demonstrate that the elongated conformation of TM6 in squid rhodopsin is stabilized by salt bridges formed with helix (H) 9. Together with the interhelical hydrogen bonds, the salt bridges between TM6 and H9 stabilize the protein conformation of squid rhodopsin and may hinder the occurrence of large conformational changes that are observed upon activation of bovine rhodopsin. © 2011 American Chemical Society

Decrement of uterine myometrial burst duration as a correlate to active labor: A Hilbert phase approach

PubMed Central

Govindan, Rathinaswamy B.; Vairavan, Srinivasan; Furdea, Adrian; Murphy, Pam; Preissl, Hubert; Eswaran, Hari

2011-01-01

We propose a novel approach based on Hilbert phase to identify the burst in the uterine myometrial activity. We apply this approach to 24 serial magnetomyographic signals recorded from four pregnant women using a 151 SQUID array system. The bursts identified with this approach are evaluated for duration and are correlated with the gestational age. In all four subjects, we find a decrease in the duration of burst as the subject approaches active labor. As was shown in animal studies, this result indicates a faster conduction time between the muscle cells which activate a larger number of muscle units in a synchronous manner. PMID:21096231

Compression dynamics of quasi-spherical wire arrays with different linear mass profiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitrofanov, K. N., E-mail: mitrofan@triniti.ru; Aleksandrov, V. V.; Gritsuk, A. N.

Results of experimental studies of the implosion of quasi-spherical wire (or metalized fiber) arrays are presented. The goal of the experiments was to achieve synchronous three-dimensional compression of the plasma produced in different regions of a quasi-spherical array into its geometrical center. To search for optimal synchronization conditions, quasi-spherical arrays with different initial profiles of the linear mass were used. The following dependences of the linear mass on the poloidal angle were used: m{sub l}(θ) ∝ sin{sup –1}θ and m{sub l}(θ) ∝ sin{sup –2}θ. The compression dynamics of such arrays was compared with that of quasi-spherical arrays without linear massmore » profiling, m{sub l}(θ) = const. To verify the experimental data, the spatiotemporal dynamics of plasma compression in quasi-spherical arrays was studied using various diagnostics. The experiments on three-dimensional implosion of quasi-spherical arrays made it possible to study how the frozen-in magnetic field of the discharge current penetrates into the array. By measuring the magnetic field in the plasma of a quasi-spherical array, information is obtained on the processes of plasma production and formation of plasma flows from the wire/fiber regions with and without an additionally deposited mass. It is found that penetration of the magnetic flux depends on the initial linear mass profile m{sub l}(θ) of the quasi-spherical array. From space-resolved spectral measurements and frame imaging of plasma X-ray emission, information is obtained on the dimensions and shape of the X-ray source formed during the implosion of a quasi-spherical array. The intensity of this source is estimated and compared with that of the Z-pinch formed during the implosion of a cylindrical array.« less

Read-out electronics for DC squid magnetic measurements

DOEpatents

Ganther, Jr., Kenneth R.; Snapp, Lowell D.

2002-01-01

Read-out electronics for DC SQUID sensor systems, the read-out electronics incorporating low Johnson noise radio-frequency flux-locked loop circuitry and digital signal processing algorithms in order to improve upon the prior art by a factor of at least ten, thereby alleviating problems caused by magnetic interference when operating DC SQUID sensor systems in magnetically unshielded environments.

75 FR 61639 - Fisheries of the Exclusive Economic Zone Off Alaska; Skate Management in the Groundfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-06

... and GOA sharks, sculpins, and octopuses, and GOA squids as a group for purposes of prohibited species.../npfmc/default.htm . One alternative previously adopted for a Tier 6 stock (squid and octopus in the GOA... groups (sharks, skates, sculpins, octopus, or squid) approaches overfishing. Response: See the response...

77 FR 74159 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

.... SUMMARY: NMFS proposes changing the butterfish mortality cap on the longfin squid fishery from a catch cap to a discard cap in Framework Adjustment 7 to the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan,. This action also proposes reducing the butterfish mortality cap for the 2013 fishing year...

3D morphology reconstruction using linear array CCD binocular stereo vision imaging system

NASA Astrophysics Data System (ADS)

Pan, Yu; Wang, Jinjiang

2018-01-01

Binocular vision imaging system, which has a small field of view, cannot reconstruct the 3-D shape of the dynamic object. We found a linear array CCD binocular vision imaging system, which uses different calibration and reconstruct methods. On the basis of the binocular vision imaging system, the linear array CCD binocular vision imaging systems which has a wider field of view can reconstruct the 3-D morphology of objects in continuous motion, and the results are accurate. This research mainly introduces the composition and principle of linear array CCD binocular vision imaging system, including the calibration, capture, matching and reconstruction of the imaging system. The system consists of two linear array cameras which were placed in special arrangements and a horizontal moving platform that can pick up objects. The internal and external parameters of the camera are obtained by calibrating in advance. And then using the camera to capture images of moving objects, the results are then matched and 3-D reconstructed. The linear array CCD binocular vision imaging systems can accurately measure the 3-D appearance of moving objects, this essay is of great significance to measure the 3-D morphology of moving objects.

Effect of single- and two-cycle high hydrostatic pressure treatments on water properties, physicochemical and microbial qualities of minimally processed squids (todarodes pacificus).

PubMed

Zhang, Yifeng; Jiao, Shunshan; Lian, Zixuan; Deng, Yun; Zhao, Yanyun

2015-05-01

This study investigated the effect of single- and two-cycle high hydrostatic pressure (HHP) treatments on water properties, physicochemical, and microbial qualities of squids (Todarodes pacificus) during 4 °C storage for up to 10 d. Single-cycle treatments were applied at 200, 400, or 600 MPa for 20 min (S-200, S-400, and S-600), and two-cycle treatments consisted of two 10 min cycles at 200, 400, or 600 MPa, respectively (T-200, T-400, and T-600). HHP-treated samples had higher (P < 0.05) content of P2b (immobilized water) and P21 (myofibril water), but lower P22 (free water) than those of control. The single- and two-cycle HHP treatments at the same pressure level caused no significant difference in water state of squids. The two-cycle HHP treatment was more effective in controlling total volatile basic nitrogen, pH, and total plate counts (TPC) of squids during storage, in which TPC of S-600 and T-600 was 2.9 and 1.8 log CFU/g at 10 d, respectively, compared with 7.5 log CFU/g in control. HHP treatments delayed browning discoloration of the squids during storage, and the higher pressure level and two-cycle HHP were more effective. Water properties highly corresponded with color and texture indices of squids. This study demonstrated that the two-cycle HHP treatment was more effective in controlling microbial growth and quality deterioration while having similar impact on the physicochemical and water properties of squids in comparison with the single-cycle treatment, thus more desirable for extending shelf-life of fresh squids. © 2015 Institute of Food Technologists®

Linear encoding device

NASA Technical Reports Server (NTRS)

Leviton, Douglas B. (Inventor)

1993-01-01

A Linear Motion Encoding device for measuring the linear motion of a moving object is disclosed in which a light source is mounted on the moving object and a position sensitive detector such as an array photodetector is mounted on a nearby stationary object. The light source emits a light beam directed towards the array photodetector such that a light spot is created on the array. An analog-to-digital converter, connected to the array photodetector is used for reading the position of the spot on the array photodetector. A microprocessor and memory is connected to the analog-to-digital converter to hold and manipulate data provided by the analog-to-digital converter on the position of the spot and to compute the linear displacement of the moving object based upon the data from the analog-to-digital converter.

A shot in the dark: same-sex sexual behaviour in a deep-sea squid.

PubMed

Hoving, Hendrik J T; Bush, Stephanie L; Robison, Bruce H

2012-04-23

Little is known about the reproductive habits of deep-living squids. Using remotely operated vehicles in the deep waters of the Monterey Submarine Canyon, we have found evidence of mating, i.e. implanted sperm packages, on similar body locations in males and females of the rarely seen mesopelagic squid Octopoteuthis deletron. Equivalent numbers of both sexes were found to have mated, indicating that male squid routinely and indiscriminately mate with both males and females. Most squid species are short-lived, semelparous (i.e. with a single, brief reproductive period) and promiscuous. In the deep, dark habitat where O. deletron lives, potential mates are few and far between. We suggest that same-sex mating behaviour by O. deletron is part of a reproductive strategy that maximizes success by inducing males to indiscriminately and swiftly inseminate every conspecific that they encounter.

77 FR 16472 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

...NMFS is implementing final 2012 specifications and management measures for Atlantic mackerel (mackerel), and 2012-2014 specifications for Illex and longfin squid, and interim final 2012 specifications and management measures for butterfish. This is the first year that the specifications are being set for Atlantic mackerel and butterfish under the provisions of the Mid-Atlantic Fishery Management Council's (Council) Annual Catch Limit and Accountability Measure Omnibus Amendment. This action also adjusts the closure threshold for the commercial mackerel fishery to 95 percent (from 90 percent), and allows the use of jigging gear to target longfin squid if the longfin squid fishery is closed due to the butterfish mortality cap. Finally, this rule makes minor corrections in existing regulatory text to clarify the intent of the regulations. These specifications and management measures promote the utilization and conservation of the Atlantic Mackerel, Squid, and Butterfish (MSB) resource.

Squid as nutrient vectors linking Southwest Atlantic marine ecosystems

NASA Astrophysics Data System (ADS)

Arkhipkin, Alexander I.

2013-10-01

Long-term investigations of three abundant nektonic squid species from the Southwest Atlantic, Illex argentinus, Doryteuthis gahi and Onykia ingens, permitted to estimate important population parameters including individual growth rates, duration of ontogenetic phases and mortalities. Using production model, the productivity of squid populations at different phases of their life cycle was assessed and the amount of biomass they convey between marine ecosystems as a result of their ontogenetic migrations was quantified. It was found that squid are major nutrient vectors and play a key role as transient 'biological pumps' linking spatially distinct marine ecosystems. I. argentinus has the largest impact in all three ecosystems it encounters due to its high abundance and productivity. The variable nature of squid populations increases the vulnerability of these biological conveyers to overfishing and environmental change. Failure of these critical biological pathways may induce irreversible long-term consequences for biodiversity, resource abundance and spatial availability in the world ocean.

A Fourier Method for Sidelobe Reduction in Equally Spaced Linear Arrays

NASA Astrophysics Data System (ADS)

Safaai-Jazi, Ahmad; Stutzman, Warren L.

2018-04-01

Uniformly excited, equally spaced linear arrays have a sidelobe level larger than -13.3 dB, which is too high for many applications. This limitation can be remedied by nonuniform excitation of array elements. We present an efficient method for sidelobe reduction in equally spaced linear arrays with low penalty on the directivity. The method involves the following steps: construction of a periodic function containing only the sidelobes of the uniformly excited array, calculation of the Fourier series of this periodic function, subtracting the series from the array factor of the original uniformly excited array after it is truncated, and finally mitigating the truncation effects which yields significant increase in sidelobe level reduction. A sidelobe reduction factor is incorporated into element currents that makes much larger sidelobe reductions possible and also allows varying the sidelobe level incrementally. It is shown that such newly formed arrays can provide sidelobe levels that are at least 22.7 dB below those of the uniformly excited arrays with the same size and number of elements. Analytical expressions for element currents are presented. Radiation characteristics of the sidelobe-reduced arrays introduced here are examined, and numerical results for directivity, sidelobe level, and half-power beam width are presented for example cases. Performance improvements over popular conventional array synthesis methods, such as Chebyshev and linear current tapered arrays, are obtained with the new method.

Advances in diagnostic ultrasonography.

PubMed

Reef, V B

1991-08-01

A wide variety of ultrasonographic equipment currently is available for use in equine practice, but no one machine is optimal for every type of imaging. Image quality is the most important factor in equipment selection once the needs of the practitioner are ascertained. The transducer frequencies available, transducer footprints, depth of field displayed, frame rate, gray scale, simultaneous electrocardiography, Doppler, and functions to modify the image are all important considerations. The ability to make measurements off of videocassette recorder playback and future upgradability should be evaluated. Linear array and sector technology are the backbone of equine ultrasonography today. Linear array technology is most useful for a high-volume broodmare practice, whereas sector technology is ideal for a more general equine practice. The curved or convex linear scanner has more applications than the standard linear array and is equipped with the linear array rectal probe, which provides the equine practitioner with a more versatile unit for equine ultrasonographic evaluations. The annular array and phased array systems have improved image quality, but each has its own limitations. The new sector scanners still provide the most versatile affordable equipment for equine general practice.

76 FR 3044 - Fisheries of the Exclusive Economic Zone Off Alaska; Sculpins, Sharks, Squid, and Octopus in the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-19

..., Squid, and Octopus in the Gulf of Alaska AGENCY: National Marine Fisheries Service (NMFS), National... prohibiting directed fishing for sculpins, sharks, squid, and octopus in the Gulf of Alaska (GOA). This action..., and octopus in the GOA. DATES: Effective 1200 hrs, Alaska local time (A.l.t.), January 13, 2011...

A YBCO RF-squid variable temperature susceptometer and its applications

NASA Technical Reports Server (NTRS)

Zhou, Luwei; Qiu, Jinwu; Zhang, Xianfeng; Tang, Zhimin; Cai, Yimin; Qian, Yongjia

1991-01-01

The Superconducting QUantum Interference Device (SQUID) susceptibility using a high-temperature radio-frequency (rf) SQUID and a normal metal pick-up coil is employed in testing weak magnetization of the sample. The magnetic moment resolution of the device is 1 x 10(exp -6) emu, and that of the susceptibility is 5 x 10(exp -6) emu/cu cm.

Macroscale and Microscale Structural Characterization of Cephalopod Chromatophores

DTIC Science & Technology

2011-04-01

ABSTRACT Cephalopods, the class of mollusks that include squid, cuttlefish, and octopus , possess skin with dynamic adaptable appearance. Their unique...Cephalopods, the class of mollusks that include squid, cuttlefish, and octopus , possess skin with dynamic adaptable appearance. Their unique ability to...Cephalopoda including cuttlefish, octopus , and squid (Hanlon, 2007; Hanlon and Messenger, 1996; Hanlon, 1982; Hanlon and Messenger, 1988). These

Designing a Microhydraulically driven Mini robotic Squid

DTIC Science & Technology

2016-05-20

applications for microrobots include remote monitoring, surveillance, search and rescue, nanoassembly, medicine, and in-vivo surgery . Robotics platforms...Secretary of Defense for Research and Engineering. Designing a Microhydraulically-driven Mini- robotic Squid by Kevin Dehan Meng B.S., U.S. Air...Committee on Graduate Students 2 Designing a Microhydraulically-driven Mini- robotic Squid by Kevin Dehan Meng Submitted to the Department

Measurement of the dynamic input impedance of a dc superconducting quantum interference device at audio frequencies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falferi, P.; Mezzena, R.; Vitale, S.

1997-08-01

The coupling effects of a commercial dc superconducting quantum interference device (SQUID) to an electrical LC resonator which operates at audio frequencies ({approx}1kHz) with quality factors Q{approx}10{sup 6} are presented. The variations of the resonance frequency of the resonator as functions of the flux applied to the SQUID are due to the SQUID dynamic inductance in good agreement with the predictions of a model. The variations of the quality factor point to a feedback mechanism between the output of the SQUID and the input circuit. {copyright} {ital 1997 American Institute of Physics.}

jSquid: a Java applet for graphical on-line network exploration.

PubMed

Klammer, Martin; Roopra, Sanjit; Sonnhammer, Erik L L

2008-06-15

jSquid is a graph visualization tool for exploring graphs from protein-protein interaction or functional coupling networks. The tool was designed for the FunCoup web site, but can be used for any similar network exploring purpose. The program offers various visualization and graph manipulation techniques to increase the utility for the user. jSquid is available for direct usage and download at http://jSquid.sbc.su.se including source code under the GPLv3 license, and input examples. It requires Java version 5 or higher to run properly. erik.sonnhammer@sbc.su.se Supplementary data are available at Bioinformatics online.

Radiofrequency amplifier based on a dc superconducting quantum interference device

DOEpatents

Hilbert, C.; Martinis, J.M.; Clarke, J.

1984-04-27

A low noise radiofrequency amplifer, using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID and an input coil are maintained at superconductivity temperatures in a superconducting shield, with the input coil inductively coupled to the superconducting ring of the dc SQUID. A radiofrequency signal from outside the shield is applied to the input coil, and an amplified radiofrequency signal is developed across the dc SQUID ring and transmitted to exteriorly of the shield. A power gain of 19.5 +- 0.5 dB has been achieved with a noise temperature of 1.0 +- 0.4 K at a frequency of 100 MHz.

[A study on feeding ecology and migration patterns of Dosidicus gigas off Peru using stable isotope analysis].

PubMed

Gong, Yi; Chen, Xin-jun; Li, Yun-kai; Han, Meng-jie

2015-09-01

As a pelagic cephalopod and one of the main target species of Chinese distant water fishery, jumbo squids (Dosidicus gigas) play a major role in the marine ecosystems of the eastern Pacific. Understanding the feeding ecology and migration patterns of jumbo squids is of importance for better utilizing the resources. The isotopic signatures of gladius, have been proved to be a powerful tool to reveal high resolution and ontogenic variations in individual foraging strategies of squids; which is an archival tissue with no elemental turnover after formation. In this study, the growth equation of gladius proostracum was established based on the age information determined by statolith. Gladius was cut successionally by the growth curve of gladius proostracum, the stable isotopic values of the gladius profiles were determined, and the feeding ecology and migration patterns of jumbo squids during its growth process were investigated. Results showed that the jumbo squids began to migrate after 180 days of postnatal, and their trophic levels tended to decrease throughout the life span. These results demonstrated the feasibility of using continuous sampling hard tissue to study the feeding ecology and habitat transfer of jumbo squids.

ESR studies on the thermal decomposition of trimethylamine oxide to formaldehyde and dimethylamine in jumbo squid (Dosidicus gigas) extract.

PubMed

Zhu, Junli; Jia, Jia; Li, Xuepeng; Dong, Liangliang; Li, Jianrong

2013-12-15

The effects of ferrous iron, heating temperature and different additives on the decomposition of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) and generation of free radicals in jumbo squid (Dosidicus gigas) extract during heating were evaluated by electron spin resonance (ESR). The thermal decomposition of TMAO to TMA, DMA and FA and free radical signals was observed in squid extract, whereas no DMA, FA and free radical signals were detected in cod extract or in aqueous TMAO solution in vitro at high temperatures. Significant increase in levels of DMA, FA and radicals intensity were observed in squid extract and TMAO solution in the presence of ferrous iron with increasing temperature. Hydrogen peroxide stimulated the production of DMA, FA and ESR signals in squid extract, while citric acid, trisodium citrate, calcium chloride, tea polyphenols and resveratrol had the opposite effect. Similar ESR spectra of six peaks regarded as amminium radical were detected in the squid extract and TMAO-iron(II) solution, suggesting that the amminium radical was involved in the decomposition of TMAO. Copyright © 2013 Elsevier Ltd. All rights reserved.

SQUIDs De-fluxing Using a Decaying AC Magnetic Field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matlashov, Andrei Nikolaevich; Semenov, Vasili Kirilovich; Anderson, Bill

Flux trapping is the Achilles’ heel of all superconductor electronics. The most direct way to avoid flux trapping is a prevention of superconductor circuits from exposure to magnetic fields. Unfortunately this is not feasible if the circuits must be exposed to a strong DC magnetic field even for a short period of time. For example, such unavoidable exposures take place in superparamagnetic relaxation measurements (SPMR) and ultra-low field magnetic resonance imaging (ULF MRI) using unshielded thin-film SQUID-based gradiometers. Unshielded SQUIDs stop working after being exposed to DC magnetic fields of only a few Gauss in strength. In this paper wemore » present experimental results with de-fluxing of planar thin-film LTS SQUID-based gradiometers using a strong decaying AC magnetic field. We used four commercial G136 gradiometers for SPMR measurements with up to a 10 mT magnetizing field. Strong 12.9 kHz decaying magnetic field pulses reliably return SQUIDs to normal operation 50 ms after zeroing the DC magnetizing field. This new AC de-fluxing method was also successfully tested with seven other different types of LTS SQUID sensors and has been shown to dissipate extremely low energy.« less

Deep-sea in situ observations of gonatid squid and their prey reveal high occurrence of cannibalism

NASA Astrophysics Data System (ADS)

Hoving, H. J. T.; Robison, B. H.

2016-10-01

In situ observations are rarely applied in food web studies of deep-sea organisms. Using deep-sea observations obtained by remotely operated vehicles in the Monterey Submarine Canyon, we examined the prey choices of more than 100 individual squids of the genus Gonatus. Off the California coast, these squids are abundant, semelparous (one reproductive cycle) oceanic predators but their diet has remained virtually unknown. Gonatus onyx and Gonatus berryi were observed to feed on mesopelagic fishes (in particular the myctophid Stenobrachius leucopsarus) as often as on squids but inter-specific differences in feeding were apparent. Gonatids were the most common squid prey and while cannibalism occurred in both species it was particularly high in Gonatus onyx (42% of all prey items). Typically, the size of prey was similar to the size of the predator but the squids were also seen to take much larger prey. Postjuvenile gonatids are opportunistic predators that consume nektonic members of the meso-and bathypelagic communities, including their own species. Such voracious feeding is likely necessary to support the high energetic demands associated with the single reproductive event; and for females the long brooding period during which they must depend on stored resources.

Sensitive Spin Detection Using An On-Chip Squid-Waveguide Resonator

NASA Astrophysics Data System (ADS)

Yue, Guang

Quantum computing gives novel way of computing using quantum mechanics, which furthers human knowledge and has exciting applications. Quantum systems with diluted spins such as rare earth ions hosted in single crystal, molecule-based magnets etc. are promising qubits candidates to form the basis of a quantum computer. High sensitivity measurement and coherent control of these spin systems are crucial for their practical usage as qubits. The micro-SQUID (direct-current micrometer-sized Superconducting QUantum Interference Device) is capable to measure magnetization of spin system with high sensitivity. For example, the micro-SQUID technique can measure magnetic moments as small as several thousand muB as shown by the study of [W. Wernsdorfer, Supercond. Sci. Technol. 22, 064013 (2009)]. Here we develop a novel on-chip setup that combines the micro-SQUID sensitivity with microwave excitation. Such setup can be used for electron spin resonance measurements or coherent control of spins utilizing the high sensitivity of micro-SQUID for signal detection. To build the setup, we studied the fabrication process of the micro-SQUID, which is made of weak-linked Josephson junctions. The SQUID as a detector is integrated on the same chip with a shorted coplanar waveguide, so that the microwave pulses can be applied through the waveguide to excite the sample for resonance measurements. The whole device is plasma etched from a thin (˜ 20nm) niobium film, so that the SQUID can work at in large in-plane magnetic fields of several tesla. In addition, computer simulations are done to find the best design of the waveguide such that the microwave excitation field is sufficiently strong and uniformly applied to the sample. The magnetization curve of Mn12 molecule-based magnet sample is measured to prove the proper working of the micro-SQUID. Electron spin resonance measurement is done on the setup for gadolinium ions diluted in a CaWO4 single crystal. The measurement shows clear evidence of the resonance signal from the 1st transition of the gadolinium ions' energy levels, which shows the setup is successfully built. Due to the high sensitivity of micro-SQUID and the ability to concentrate microwave energy in small areas of the chip, this setup can detect signals from a small number of spins (107) in a small volume (several mum 3).

Modulation Transfer Function (MTF) measurement techniques for lenses and linear detector arrays

NASA Technical Reports Server (NTRS)

Schnabel, J. J., Jr.; Kaishoven, J. E., Jr.; Tom, D.

1984-01-01

Application is the determination of the Modulation Transfer Function (MTF) for linear detector arrays. A system set up requires knowledge of the MTF of the imaging lens. Procedure for this measurement is described for standard optical lab equipment. Given this information, various possible approaches to MTF measurement for linear arrays is described. The knife edge method is then described in detail.

The Cold Dark Matter Search test stand warm electronics card

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hines, Bruce; /Colorado U., Denver; Hansen, Sten

A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

The giant eyes of giant squid are indeed unexpectedly large, but not if used for spotting sperm whales.

PubMed

Nilsson, Dan-E; Warrant, Eric J; Johnsen, Sönke; Hanlon, Roger T; Shashar, Nadav

2013-09-08

We recently reported (Curr Biol 22:683-688, 2012) that the eyes of giant and colossal squid can grow to three times the diameter of the eyes of any other animal, including large fishes and whales. As an explanation to this extreme absolute eye size, we developed a theory for visual performance in aquatic habitats, leading to the conclusion that the huge eyes of giant and colossal squid are uniquely suited for detection of sperm whales, which are important squid-predators in the depths where these squid live. A paper in this journal by Schmitz et al. (BMC Evol Biol 13:45, 2013) refutes our conclusions on the basis of two claims: (1) using allometric data they argue that the eyes of giant and colossal squid are not unexpectedly large for the size of the squid, and (2) a revision of the values used for modelling indicates that large eyes are not better for detection of approaching sperm whales than they are for any other task. We agree with Schmitz et al. that their revised values for intensity and abundance of planktonic bioluminescence may be more realistic, or at least more appropriately conservative, but argue that their conclusions are incorrect because they have not considered some of the main arguments put forward in our paper. We also present new modelling to demonstrate that our conclusions remain robust, even with the revised input values suggested by Schmitz et al.

Application of linear array imaging techniques to the real-time inspection of airframe structures and substructures

NASA Technical Reports Server (NTRS)

Miller, James G.

1995-01-01

Development and application of linear array imaging technologies to address specific aging-aircraft inspection issues is described. Real-time video-taped images were obtained from an unmodified commercial linear-array medical scanner of specimens constructed to simulate typical types of flaws encountered in the inspection of aircraft structures. Results suggest that information regarding the characteristics, location, and interface properties of specific types of flaws in materials and structures may be obtained from the images acquired with a linear array. Furthermore, linear array imaging may offer the advantage of being able to compare 'good' regions with 'flawed' regions simultaneously, and in real time. Real-time imaging permits the inspector to obtain image information from various views and provides the opportunity for observing the effects of introducing specific interventions. Observation of an image in real-time can offer the operator the ability to 'interact' with the inspection process, thus providing new capabilities, and perhaps, new approaches to nondestructive inspections.

75 FR 1024 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-08

... rulemaking (ANPR); notice to reaffirm the control date for the Loligo squid (Loligo) and Illex squid (Illex...: Public comments on the ANPR must be received no later than 5 p.m., eastern standard time, on February 8... fisheries since 2003. On May 20, 2003 (68 FR 27516), NMFS published, at the request of the Council, an ANPR...

Comparison of characteristics and downstream uniformity of linear-field and cross-field atmospheric pressure plasma jet array in He

NASA Astrophysics Data System (ADS)

Zhang, Bo; Fang, Zhi; Liu, Feng; Zhou, Renwu; Zhou, Ruoyu

2018-06-01

Using an atmospheric pressure plasma jet array is an effective way for expanding the treatment area of a single jet, and generating arrays with well downstream uniformity is of great interest for its applications. In this paper, a plasma jet array in helium is generated in a linear-field jet array with a ring-ring electrode structure excited by alternating current. The characteristics and downstream uniformity of the array and their dependence on the applied voltage and gas flow rate are investigated through optical, electrical, and Schlieren diagnostics. The results are compared with those of our reported work of a cross-field jet array with a needle-ring electrode structure. The results show that the linear-field jet array can generate relatively large-scale plasma with better uniformity and longer plumes than the cross-field case. The divergences observed in gas channels and the plasma plume trajectories are much less than those of the cross-field one. The deflection angle of lateral plumes is less than 6°, which is independent of the gas flow rate and applied voltage. The maximum downstream plumes of 23 mm can be obtained at 7 kV peak applied voltage and 4 l/min gas flow rate. The better uniformity of linear-field jet arrays is due to the effective suppression of hydrodynamic and electrical interactions among the jets in the arrays with a more uniform electric field distribution. The hydrodynamic interaction induced by the gas heating in the linear-field jet array is less than that of the cross-field one. The more uniform electric field distribution in the linear-field jet arrays can reduce the divergence of the propagation trajectories of the plasma plumes. It will generate less residual charge between the adjacent discharges and thus can reduce the accumulation effect of Coulomb force between the plasma plumes. The reported results can help design controllable and scalable plasma jet arrays with well uniformity for material surface and biomedical treatments.

Linearly tapered slot antenna circular array for mobile communications

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Kelly, Eron; Lee, Richard Q.; Taub, Susan R.

1993-01-01

The design, fabrication and testing of a conformal K-band circular array is presented. The array consists of sixteen linearly tapered slot antennas (LTSA). It is fed by a 1:16 microstrip line power splitter via electromagnetic coupling. The array has an omni-directional pattern in the azimuth plane. In the elevation plane the beam is displaced above the horizon.

SQUIDs in biomagnetism: a roadmap towards improved healthcare

NASA Astrophysics Data System (ADS)

Körber, Rainer; Storm, Jan-Hendrik; Seton, Hugh; Mäkelä, Jyrki P.; Paetau, Ritva; Parkkonen, Lauri; Pfeiffer, Christoph; Riaz, Bushra; Schneiderman, Justin F.; Dong, Hui; Hwang, Seong-min; You, Lixing; Inglis, Ben; Clarke, John; Espy, Michelle A.; Ilmoniemi, Risto J.; Magnelind, Per E.; Matlashov, Andrei N.; Nieminen, Jaakko O.; Volegov, Petr L.; Zevenhoven, Koos C. J.; Höfner, Nora; Burghoff, Martin; Enpuku, Keiji; Yang, S. Y.; Chieh, Jen-Jei; Knuutila, Jukka; Laine, Petteri; Nenonen, Jukka

2016-11-01

Globally, the demand for improved health care delivery while managing escalating costs is a major challenge. Measuring the biomagnetic fields that emanate from the human brain already impacts the treatment of epilepsy, brain tumours and other brain disorders. This roadmap explores how superconducting technologies are poised to impact health care. Biomagnetism is the study of magnetic fields of biological origin. Biomagnetic fields are typically very weak, often in the femtotesla range, making their measurement challenging. The earliest in vivo human measurements were made with room-temperature coils. In 1963, Baule and McFee (1963 Am. Heart J. 55 95-6) reported the magnetic field produced by electric currents in the heart (‘magnetocardiography’), and in 1968, Cohen (1968 Science 161 784-6) described the magnetic field generated by alpha-rhythm currents in the brain (‘magnetoencephalography’). Subsequently, in 1970, Cohen et al (1970 Appl. Phys. Lett. 16 278-80) reported the recording of a magnetocardiogram using a Superconducting QUantum Interference Device (SQUID). Just two years later, in 1972, Cohen (1972 Science 175 664-6) described the use of a SQUID in magnetoencephalography. These last two papers set the scene for applications of SQUIDs in biomagnetism, the subject of this roadmap. The SQUID is a combination of two fundamental properties of superconductors. The first is flux quantization—the fact that the magnetic flux Φ in a closed superconducting loop is quantized in units of the magnetic flux quantum, Φ0 ≡ h/2e, ≈ 2.07 × 10-15 Tm2 (Deaver and Fairbank 1961 Phys. Rev. Lett. 7 43-6, Doll R and Näbauer M 1961 Phys. Rev. Lett. 7 51-2). Here, h is the Planck constant and e the elementary charge. The second property is the Josephson effect, predicted in 1962 by Josephson (1962 Phys. Lett. 1 251-3) and observed by Anderson and Rowell (1963 Phys. Rev. Lett. 10 230-2) in 1963. The Josephson junction consists of two weakly coupled superconductors separated by a tunnel barrier or other weak link. A tiny electric current is able to flow between the superconductors as a supercurrent, without developing a voltage across them. At currents above the ‘critical current’ (maximum supercurrent), however, a voltage is developed. In 1964, Jaklevic et al (1964 Phys. Rev. Lett. 12 159-60) observed quantum interference between two Josephson junctions connected in series on a superconducting loop, giving birth to the dc SQUID. The essential property of the SQUID is that a steady increase in the magnetic flux threading the loop causes the critical current to oscillate with a period of one flux quantum. In today’s SQUIDs, using conventional semiconductor readout electronics, one can typically detect a change in Φ corresponding to 10-6 Φ0 in one second. Although early practical SQUIDs were usually made from bulk superconductors, for example, niobium or Pb-Sn solder blobs, today’s devices are invariably made from thin superconducting films patterned with photolithography or even electron lithography. An extensive description of SQUIDs and their applications can be found in the SQUID Handbooks (Clarke and Braginski 2004 Fundamentals and Technology of SQUIDs and SQUID Systems vol I (Weinheim, Germany: Wiley-VCH), Clarke and Braginski 2006 Applications of SQUIDs and SQUID Systems vol II (Weinheim, Germany: Wiley-VCH)). The roadmap begins (chapter 1) with a brief review of the state-of-the-art of SQUID-based magnetometers and gradiometers for biomagnetic measurements. The magnetic field noise referred to the pick-up loop is typically a few fT Hz-1/2, often limited by noise in the metallized thermal insulation of the dewar rather than by intrinsic SQUID noise. The authors describe a pathway to achieve an intrinsic magnetic field noise as low as 0.1 fT Hz-1/2, approximately the Nyquist noise of the human body. They also descibe a technology to defeat dewar noise. Chapter 2 reviews the neuroscientific and clinical use of magnetoencephalography (MEG), by far the most widespread application of biomagnetism with systems containing typically 300 sensors cooled to liquid-helium temperature, 4.2 K. Two important clinical applications are presurgical mapping of focal epilepsy and of eloquent cortex in brain-tumor patients. Reducing the sensor-to-brain separation and the system noise level would both improve spatial resolution. The very recent commercial innovation that replaces the need for frequent manual transfer of liquid helium with an automated system that collects and liquefies the gas and transfers the liquid to the dewar will make MEG systems more accessible. A highly promising means of placing the sensors substantially closer to the scalp for MEG is to use high-transition-temperature (high-T c) SQUID sensors and flux transformers (chapter 3). Operation of these devices at liquid-nitrogen temperature, 77 K, enables one to minimize or even omit metallic thermal insulation between the sensors and the dewar. Noise levels of a few fT Hz-1/2 have already been achieved, and lower values are likely. The dewars can be made relatively flexible, and thus able to be placed close to the skull irrespective of the size of the head, potentially providing higher spatial resolution than liquid-helium based systems. The successful realization of a commercial high-T c MEG system would have a major commercial impact. Chapter 4 introduces the concept of SQUID-based ultra-low-field magnetic resonance imaging (ULF MRI) operating at typically several kHz, some four orders of magnitude lower than conventional, clinical MRI machines. Potential advantages of ULF MRI include higher image contrast than for conventional MRI, enabling methodologies not currently available. Examples include screening for cancer without a contrast agent, imaging traumatic brain injury (TBI) and degenerative diseases such as Alzheimer’s, and determining the elapsed time since a stroke. The major current problem with ULF MRI is that its signal-to-noise ratio (SNR) is low compared with high-field MRI. Realistic solutions to this problem are proposed, including implementing sensors with a noise level of 0.1 fT Hz-1/2. A logical and exciting prospect (chapter 5) is to combine MEG and ULF MRI into a single system in which both signal sources are detected with the same array of SQUIDs. A prototype system is described. The combination of MEG and ULF MRI allows one to obtain structural images of the head concurrently with the recording of brain activity. Since all MEG images require an MRI to determine source locations underlying the MEG signal, the combined modality would give a precise registration of the two images; the combination of MEG with high-field MRI can produce registration errors as large as 5 mm. The use of multiple sensors for ULF MRI increases both the SNR and the field of view. Chapter 6 describes another potentially far-reaching application of ULF MRI, namely neuronal current imaging (NCI) of the brain. Currently available neuronal imaging techniques include MEG, which is fast but has relatively poor spatial resolution, perhaps 10 mm, and functional MRI (fMRI) which has a millimeter resolution but is slow, on the order of seconds, and furthermore does not directly measure neuronal signals. NCI combines the ability of direct measurement of MEG with the spatial precision of MRI. In essence, the magnetic fields generated by neural currents shift the frequency of the magnetic resonance signal at a location that is imaged by the three-dimensional magnetic field gradients that form the basis of MRI. The currently achieved sensitivity of NCI is not quite sufficient to realize its goal, but it is close. The realization of NCI would represent a revolution in functional brain imaging. Improved techniques for immunoassay are always being sought, and chapter 7 introduces an entirely new topic, magnetic nanoparticles for immunoassay. These particles are bio-funtionalized, for example with a specific antibody which binds to its corresponding antigen, if it is present. Any resulting changes in the properties of the nanoparticles are detected with a SQUID. For liquid-phase detection, there are three basic methods: AC susceptibility, magnetic relaxation and remanence measurement. These methods, which have been successfully implemented for both in vivo and ex vivo applications, are highly sensitive and, although further development is required, it appears highly likely that at least some of them will be commercialized. Chapter 8 concludes the roadmap with an assessment of the commercial market for MEG systems. Despite the huge advances that have been realized since MEG was first introduced, the number of commercial systems deployed around the world remains small, around 250 units employing about 50 000 SQUIDs. The slow adoption of this technology is undoubtedly in part due to the high cost, not least because of the need to surround the entire system in an expensive magnetically shielded room. Nonetheless, the recent introduction of automatically refilling liquid-helium systems, the ongoing reduction in sensor noise, the potential availability of high-T c SQUID systems, the availability of new and better software and the combination of MEG with ULF MRI all have the potential to increase the market size in the not-so-distant future. In particular, there is a great and growing need for better noninvasive technologies to measure brain function. There are hundreds of millions of people in the world who suffer from brain disorders such as epilepsy, stroke, dementia or depression. The enormous cost to society of these diseases can be reduced by earlier and more accurate detection and diagnosis. Once the challenges outlined in this roadmap have been met and the outstanding problems have been solved, the potential demand for SQUID-based health technology can be expected to increase by ten- if not hundred-fold.

A linear refractive photovoltaic concentrator solar array flight experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, P.A.; Murphy, D.M.; Piszczor, M.F.

1995-12-31

Concentrator arrays deliver a number of generic benefits for space including high array efficiency, protection from space radiation effects, and minimized plasma interactions. The line focus concentrator concept delivers two added advantages: (1) low-cost mass production of the lens material and, (2) relaxation of precise array tracking requirements to only a single axis. New array designs emphasize lightweight, high stiffness, stow-ability and ease of manufacture and assembly. The linear refractive concentrator can be designed to provide an essentially flat response over a wide range of longitudinal pointing errors for satellites having only single-axis tracking capability. In this paper the authorsmore » address the current status of the SCARLET linear concentrator program with special emphasis on hardware development of an array-level linear refractive concentrator flight experiment. An aggressive, 6-month development and flight validation program, sponsored by the Ballistic Missile Defense Organization (BMDO) and NASA Lewis Research Center, will quantify and verify SCARLET benefits with in-orbit performance measurements.« less

Off-Grid Direction of Arrival Estimation Based on Joint Spatial Sparsity for Distributed Sparse Linear Arrays

PubMed Central

Liang, Yujie; Ying, Rendong; Lu, Zhenqi; Liu, Peilin

2014-01-01

In the design phase of sensor arrays during array signal processing, the estimation performance and system cost are largely determined by array aperture size. In this article, we address the problem of joint direction-of-arrival (DOA) estimation with distributed sparse linear arrays (SLAs) and propose an off-grid synchronous approach based on distributed compressed sensing to obtain larger array aperture. We focus on the complex source distribution in the practical applications and classify the sources into common and innovation parts according to whether a signal of source can impinge on all the SLAs or a specific one. For each SLA, we construct a corresponding virtual uniform linear array (ULA) to create the relationship of random linear map between the signals respectively observed by these two arrays. The signal ensembles including the common/innovation sources for different SLAs are abstracted as a joint spatial sparsity model. And we use the minimization of concatenated atomic norm via semidefinite programming to solve the problem of joint DOA estimation. Joint calculation of the signals observed by all the SLAs exploits their redundancy caused by the common sources and decreases the requirement of array size. The numerical results illustrate the advantages of the proposed approach. PMID:25420150

Second order gradiometer and dc SQUID integrated on a planar substrate

NASA Astrophysics Data System (ADS)

van Nieuwenhuyzen, G. J.; de Waal, V. J.

1985-02-01

An integrated system of a thin-film niobium dc superconducting quantum interference device (SQUID) and a second order gradiometer on a planar substrate is described. The system consists of a dc SQUID with eight loops in parallel, each sensitive to the second derivative ∂2Bz/∂x2 of the magnetic field. The calculated SQUID inductance is 1.3 nH. With an overall size of 16×16.5 mm2 a sensitivity of 1.5×10-9 Tm-2 Hz-1/2 is obtained. The measured transfer function for uniform fields perpendicular to the plane of the gradiometer is 2.1×10-7 T Φ-10.

Routine clinical heart examinations using SQUID magnetocardiography at University of Tsukuba Hospital

NASA Astrophysics Data System (ADS)

Inaba, T.; Nakazawa, Y.; Yoshida, K.; Kato, Y.; Hattori, A.; Kimura, T.; Hoshi, T.; Ishizu, T.; Seo, Y.; Sato, A.; Sekiguchi, Y.; Nogami, A.; Watanabe, S.; Horigome, H.; Kawakami, Y.; Aonuma, K.

2017-11-01

A 64-channel Nb-based DC-SQUID magnetocardiography (MCG) system was installed at the University of Tsukuba Hospital (UTH) in March 2007 after obtaining Japanese pharmaceutical approval and insurance reimbursement approval. In the period between 2008 and 2016, the total number of patients was 10 085. The heart diseases diagnosed in fetuses as well as adults are mainly atrial arrhythmia, abnormal repolarization, ventricular arrhythmia, and fetal arrhythmia. In most cases of insufficient diagnostic accuracy with electrocardiography, SQUID MCG precisely revealed these heart diseases as an abnormal electrical current distribution. Based on success in routine examinations, SQUID MCG is now an indispensable clinical instrument with diagnostic software tuned up during routine use at UTH.

Micro-machined high-frequency (80 MHz) PZT thick film linear arrays.

PubMed

Zhou, Qifa; Wu, Dawei; Liu, Changgeng; Zhu, Benpeng; Djuth, Frank; Shung, K

2010-10-01

This paper presents the development of a micromachined high-frequency linear array using PZT piezoelectric thick films. The linear array has 32 elements with an element width of 24 μm and an element length of 4 mm. Array elements were fabricated by deep reactive ion etching of PZT thick films, which were prepared from spin-coating of PZT sol-gel composite. Detailed fabrication processes, especially PZT thick film etching conditions and a novel transferring-and-etching method, are presented and discussed. Array designs were evaluated by simulation. Experimental measurements show that the array had a center frequency of 80 MHz and a fractional bandwidth (-6 dB) of 60%. An insertion loss of -41 dB and adjacent element crosstalk of -21 dB were found at the center frequency.

A Mathematical Evaluation of the Core Conductor Model

PubMed Central

Clark, John; Plonsey, Robert

1966-01-01

This paper is a mathematical evaluation of the core conductor model where its three dimensionality is taken into account. The problem considered is that of a single, active, unmyelinated nerve fiber situated in an extensive, homogeneous, conducting medium. Expressions for the various core conductor parameters have been derived in a mathematically rigorous manner according to the principles of electromagnetic theory. The purpose of employing mathematical rigor in this study is to bring to light the inherent assumptions of the one dimensional core conductor model, providing a method of evaluating the accuracy of this linear model. Based on the use of synthetic squid axon data, the conclusion of this study is that the linear core conductor model is a good approximation for internal but not external parameters. PMID:5903155

Spinal cord evoked magnetic field measurement using a magnetospinography system equipped with a cryocooler.

PubMed

Adachi, Yoshiaki; Oyama, Daisuke; Kawai, Jun; Kawabata, Shigenori; Uehara, Gen

2013-01-01

We have developed a magnetospinography (MSG) system that detects weak magnetic fields associated with spinal cord neural activity using an array of low-temperature superconducting quantum interference device (SQUID)-based magnetic flux sensors. A functional image of the spinal cord can be obtained noninvasively by using this system, and it is effective for precise lesion localization in the diagnosis of spinal cord diseases. The running cost of the developed MSG system mainly depends on liquid helium (LHe) consumption, which is required to maintain the superconducting state of the SQUID sensors. To reduce the LHe consumption, we incorporate a pulse-tube-refrigerator-based cryocooler into the MSG system. Cold gaseous helium is circulated between the cryocooler and the MSG system for cooling the thermal radiation shield of the dewar vessel. Consequently, we achieved a 46% decrease in the LHe consumption rate. Conventional biomagnetic field detection such as magnetoencephalography is often hindered by severe low-frequency band noise from the cryocooler. However, in the case of MSG measurements, such noise can be filtered out because the band of the signal is much higher than that of the cryocooler noise. We demonstrated that the signal-to-noise ratio of the cervical spinal cord evoked magnetic field measurement performed with a working cryocooler is comparable to that of the measurement without a cryocooler.

A highly distributed Bragg stack with unique geometry provides effective camouflage for Loliginid squid eyes

PubMed Central

Holt, Amanda L.; Sweeney, Alison M.; Johnsen, Sönke; Morse, Daniel E.

2011-01-01

Cephalopods possess a sophisticated array of mechanisms to achieve camouflage in dynamic underwater environments. While active mechanisms such as chromatophore patterning and body posturing are well known, passive mechanisms such as manipulating light with highly evolved reflectors may also play an important role. To explore the contribution of passive mechanisms to cephalopod camouflage, we investigated the optical and biochemical properties of the silver layer covering the eye of the California fishery squid, Loligo opalescens. We discovered a novel nested-spindle geometry whose correlated structure effectively emulates a randomly distributed Bragg reflector (DBR), with a range of spatial frequencies resulting in broadband visible reflectance, making it a nearly ideal passive camouflage material for the depth at which these animals live. We used the transfer-matrix method of optical modelling to investigate specular reflection from the spindle structures, demonstrating that a DBR with widely distributed thickness variations of high refractive index elements is sufficient to yield broadband reflectance over visible wavelengths, and that unlike DBRs with one or a few spatial frequencies, this broadband reflectance occurs from a wide range of viewing angles. The spindle shape of the cells may facilitate self-assembly of a random DBR to achieve smooth spatial distributions in refractive indices. This design lends itself to technological imitation to achieve a DBR with wide range of smoothly varying layer thicknesses in a facile, inexpensive manner. PMID:21325315

Low-noise SQUID

DOEpatents

Dantsker, Eugene; Clarke, John

2000-01-01

The present invention comprises a high-transition-temperature superconducting device having low-magnitude low-frequency noise-characteristics in magnetic fields comprising superconducting films wherein the films have a width that is less than or equal to a critical width, w.sub.C, which depends on an ambient magnetic field. For operation in the Earth's magnetic field, the critical width is about 6 micrometers (.mu.m). When made with film widths of about 4 .mu.m an inventive high transition-temperature, superconducting quantum interference device (SQUID) excluded magnetic flux vortices up to a threshold ambient magnetic field of about 100 microTesla (.mu.T). SQUIDs were fabricated having several different film strip patterns. When the film strip width was kept at about 4 .mu.m, the SQUIDs exhibited essentially no increase in low-frequency noise, even when cooled in static magnetic fields of magnitude up to 100 .mu.T. Furthermore, the mutual inductance between the inventive devices and a seven-turn spiral coil was at least 85% of that for inductive coupling to a conventional SQUID.

Combined climate- and prey-mediated range expansion of Humboldt squid (Dosidicus gigas), a large marine predator in the California Current System.

PubMed

Stewart, Julia S; Hazen, Elliott L; Bograd, Steven J; Byrnes, Jarrett E K; Foley, David G; Gilly, William F; Robison, Bruce H; Field, John C

2014-06-01

Climate-driven range shifts are ongoing in pelagic marine environments, and ecosystems must respond to combined effects of altered species distributions and environmental drivers. Hypoxic oxygen minimum zones (OMZs) in midwater environments are shoaling globally; this can affect distributions of species both geographically and vertically along with predator-prey dynamics. Humboldt (jumbo) squid (Dosidicus gigas) are highly migratory predators adapted to hypoxic conditions that may be deleterious to their competitors and predators. Consequently, OMZ shoaling may preferentially facilitate foraging opportunities for Humboldt squid. With two separate modeling approaches using unique, long-term data based on in situ observations of predator, prey, and environmental variables, our analyses suggest that Humboldt squid are indirectly affected by OMZ shoaling through effects on a primary food source, myctophid fishes. Our results suggest that this indirect linkage between hypoxia and foraging is an important driver of the ongoing range expansion of Humboldt squid in the northeastern Pacific Ocean. © 2014 John Wiley & Sons Ltd.

Current-induced SQUID behavior of superconducting Nb nano-rings

NASA Astrophysics Data System (ADS)

Sharon, Omri J.; Shaulov, Avner; Berger, Jorge; Sharoni, Amos; Yeshurun, Yosef

2016-06-01

The critical temperature in a superconducting ring changes periodically with the magnetic flux threading it, giving rise to the well-known Little-Parks magnetoresistance oscillations. Periodic changes of the critical current in a superconducting quantum interference device (SQUID), consisting of two Josephson junctions in a ring, lead to a different type of magnetoresistance oscillations utilized in detecting extremely small changes in magnetic fields. Here we demonstrate current-induced switching between Little-Parks and SQUID magnetoresistance oscillations in a superconducting nano-ring without Josephson junctions. Our measurements in Nb nano-rings show that as the bias current increases, the parabolic Little-Parks magnetoresistance oscillations become sinusoidal and eventually transform into oscillations typical of a SQUID. We associate this phenomenon with the flux-induced non-uniformity of the order parameter along a superconducting nano-ring, arising from the superconducting leads (‘arms’) attached to it. Current enhanced phase slip rates at the points with minimal order parameter create effective Josephson junctions in the ring, switching it into a SQUID.

ELECTROPHORETIC AND IMMUNOLOGICAL STUDIES OF SQUID AXOPLASM PROTEINS.

PubMed

HUNEEUS-COX, F

1964-03-06

By disc electrophoresis of the axoplasm of Dosidicus gigas, 14 protein bands have been resolved. Anti-bodies to the intra-axonal proteins and to squid blood proteins were produced in rabbits. By Ouchterlony's technique, six antigenic components can be demonstrated in axoplasm; the combined use of disc electrophoresis and immune diflusion in agar resolves seven antigenic components in axoplasm; none of these components is detectable in squid blood.

Study on signal intensity of low field nuclear magnetic resonance via an indirect coupling measurement

NASA Astrophysics Data System (ADS)

Jiang, Feng-Ying; Wang, Ning; Jin, Yi-Rong; Deng, Hui; Tian, Ye; Lang, Pei-Lin; Li, Jie; Chen, Ying-Fei; Zheng, Dong-Ning

2013-04-01

We carry out an ultra-low-field nuclear magnetic resonance (NMR) experiment based on high-Tc superconducting quantum interference devices (SQUIDs). The measurement field is in a micro-tesla range (~10 μT-100 μT) and the experiment is conducted in a home-made magnetically-shielded-room (MSR). The measurements are performed by the indirect coupling method in which the signal of nuclei precession is indirectly coupled to the SQUID through a tuned copper coil transformer. In such an arrangement, the interferences of applied measurement and polarization field to the SQUID sensor are avoided and the performance of the SQUID is not destroyed. In order to compare the detection sensitivity obtained by using the SQUID with that achieved using a conventional low-noise-amplifier, we perform the measurements using a commercial room temperature amplifier. The results show that in a wide frequency range (~1 kHz-10 kHz) the measurements with the SQUID sensor exhibit a higher signal-to-noise ratio. Further, we discuss the dependence of NMR peak magnitude on measurement frequency. We attribute the reduction of the peak magnitude at high frequency to the increased field inhomogeneity as the measurement field increases. This is verified by compensating the field gradient using three sets of gradient coils.

Squid - a simple bioinformatics grid.

PubMed

Carvalho, Paulo C; Glória, Rafael V; de Miranda, Antonio B; Degrave, Wim M

2005-08-03

BLAST is a widely used genetic research tool for analysis of similarity between nucleotide and protein sequences. This paper presents a software application entitled "Squid" that makes use of grid technology. The current version, as an example, is configured for BLAST applications, but adaptation for other computing intensive repetitive tasks can be easily accomplished in the open source version. This enables the allocation of remote resources to perform distributed computing, making large BLAST queries viable without the need of high-end computers. Most distributed computing / grid solutions have complex installation procedures requiring a computer specialist, or have limitations regarding operating systems. Squid is a multi-platform, open-source program designed to "keep things simple" while offering high-end computing power for large scale applications. Squid also has an efficient fault tolerance and crash recovery system against data loss, being able to re-route jobs upon node failure and recover even if the master machine fails. Our results show that a Squid application, working with N nodes and proper network resources, can process BLAST queries almost N times faster than if working with only one computer. Squid offers high-end computing, even for the non-specialist, and is freely available at the project web site. Its open-source and binary Windows distributions contain detailed instructions and a "plug-n-play" instalation containing a pre-configured example.

Linear antenna array optimization using flower pollination algorithm.

PubMed

Saxena, Prerna; Kothari, Ashwin

2016-01-01

Flower pollination algorithm (FPA) is a new nature-inspired evolutionary algorithm used to solve multi-objective optimization problems. The aim of this paper is to introduce FPA to the electromagnetics and antenna community for the optimization of linear antenna arrays. FPA is applied for the first time to linear array so as to obtain optimized antenna positions in order to achieve an array pattern with minimum side lobe level along with placement of deep nulls in desired directions. Various design examples are presented that illustrate the use of FPA for linear antenna array optimization, and subsequently the results are validated by benchmarking along with results obtained using other state-of-the-art, nature-inspired evolutionary algorithms such as particle swarm optimization, ant colony optimization and cat swarm optimization. The results suggest that in most cases, FPA outperforms the other evolutionary algorithms and at times it yields a similar performance.

Out-Phased Array Linearized Signaling (OPALS): A Practical Approach to Physical Layer Encryption

DTIC Science & Technology

2015-10-26

Out-Phased Array Linearized Signaling ( OPALS ): A Practical Approach to Physical Layer Encryption Eric Tollefson, Bruce R. Jordan Jr., and Joseph D... OPALS ) which provides a practical approach to physical-layer encryption through spatial masking. Our approach modifies just the transmitter to employ...of the channel. With Out-Phased Array Linearized Signaling ( OPALS ), we propose a new masking technique that has some advantages of each of the

Horizontal movements, vertical-habitat utilization and diet of the jumbo squid ( Dosidicus gigas) in the Pacific Ocean off Baja California Sur, Mexico

NASA Astrophysics Data System (ADS)

Bazzino, Gastón; Gilly, William F.; Markaida, Unai; Salinas-Zavala, César A.; Ramos-Castillejos, Jorge

2010-07-01

We deployed four pop-up archival-transmitting (PAT) tags on jumbo squid ( Dosidicus gigas) collected in the Pacific Ocean off the main entrance to Magdalena Bay on the Baja California peninsula in June 2005. This is the first successful deployment of PAT tags on jumbo squid in an area outside the Gulf of California. Summary data were obtained through the ARGOS satellite system for three of the tags; the fourth tag was physically recovered. All of the tagged squid tended to remain on the shallow continental shelf for several days after tagging and then moved offshore into deeper water. Three of the four squid appeared to migrate in a general southerly direction while the fourth remained offshore of Magdalena Bay. All of the squid spent most daylight hours at depths that were associated with the hypoxic oxygen minimum layer, and at night they spent a majority of time in the upper 50 m of the water column. Stomach content analysis and tag temperature-depth data during the first days after tagging revealed that the squid were feeding on pelagic red crabs ( Pleuroncodes planipes) and several larger, neritic fishes over the continental shelf off Magdalena Bay during a seasonal nearshore upwelling. Comparison of our results with those previously collected in the Gulf of California reveal that Dosidicus gigas can vary its behavior and diet to suit local environmental conditions. This adaptability is likely to be an important factor in the ability of D. gigas to invade and colonize new areas.

Therapy of myeloma in vivo using marine phospholipid in combination with Agaricus blazei Murill as an immune respond activator.

PubMed

Murakawa, Kentaro; Fukunaga, Kenji; Tanouchi, Masatoshi; Hosokawa, Masashi; Hossain, Zakir; Takahashi, Koretaro

2007-01-01

Mushroom (Agaricus blazei Murill) extract has been reported to possess antitumor effects through immune activation. Here, we investigated the beneficial effects of combining A. blazei extract with marine phospholipids in comparison to A. blazei extract alone on myeloma sp2 tumor suppression when orally administrated. The experimental groups designed for sp2 tumor bearing BALB/c nu/nu mice were drinks of: (1)control; (2)1.0 mg/mL squid phospholipid liposome alone; (3)0.5 mg/mL A. blazei Murill water extract alone; (4)1.0 mg/mL squid phospholipid liposome with 0.5 mg/mL A. blazei Murill water extract in the form of those simple mixture; and (5)1.0 mg/mL squid phospholipid liposome with 0.5 mg/mL A. blazei Murill water extract partially encapsulated. Orally administrated volumes amounted to approximately 5 mL per day per mouse for all groups. A. blazei Murill water extract alone and squid phospholipid alone served groups show moderate tumor suppression with total administrations of approximately 105 mg/mouse for squid phospholipid through out the experimental term. When both A. blazei Murill water extract and squid phospholipid were administrated simultaneously in a simple mixture form, promotional effect on cancer tumor suppression was observed. And when A. blazei Murill water extract was partially encapsulated in the squid phospholipid liposomes with total administrations being 105 mg/mouse for squid phospholipid, effect on cancer tumor suppression was more pronounced. Though there was no statistically significant difference in tumor sizes between the simple mixture form administrated group i.e. group (4) and the partially encapsulated form administrated group i.e. group (5), the tumor vanished mouse was seen in the partially encapsulated form administrated group. Thus it was concluded that combinational administration of the A. blazei Murill water extract and the marine phospholipid may be useful in myeloma sp2 therapy.

Fabrication of sapphire-based high performance step-edge HTS Josephson junctions and SQUIDs and their application to scanning SQUID microscopy

NASA Astrophysics Data System (ADS)

Ming, Bin

Josephson junctions are at the heart of any superconductor device applications. A SQUID (Superconducting Quantum Interference Device), which consists of two Josephson junctions, is by far the most important example. Unfortunately, in the case of high-Tc superconductors (HTS), the quest for a robust, flexible, and high performance junction technology is yet far from the end. Currently, the only proven method to make HTS junctions is the SrTiO3(STO)-based bicrystal technology. In this thesis we concentrate on the fabrication of YBCO step-edge junctions and SQUIDs on sapphire. The step-edge method provides complete control of device locations and facilitates sophisticated, high-density layout. We select CeO2 as the buffer layer, as the key step to make device quality YBCO thin films on sapphire. With an "overhang" shadow mask produced by a novel photolithography technique, a steep step edge was fabricated on the CeO2 buffer layer by Ar+ ion milling with optimized parameters for minimum ion beam divergence. The step angle was determined to be in excess of 80° by atomic force microscopy (AFM). Josephson junctions patterned from those step edges exhibited resistively shunted junction (RSJ) like current-voltage characteristics. IcR n values in the 200--500 mV range were measured at 77K. Shapiro steps were observed under microwave irradiation, reflecting the true Josephson nature of those junctions. The magnetic field dependence of the junction Ic indicates a uniform current distribution. These results suggest that all fabrication processes are well controlled and the step edge is relatively straight and free of microstructural defects. The SQUIDs made from the same process exhibit large voltage modulation in a varying magnetic field. At 77K, our sapphire-based step-edge SQUID has a low white noise level at 3muphi0/ Hz , as compared to typically >10muphi0/ Hz from the best bicrystal STO SQUIDS. Our effort at device fabrication is chiefly motivated by the scanning SQUID microscopy (SSM) application. A scanning SQUID microscope is a non-contact, non-destructive imaging tool that can resolve weak currents beneath the sample surface by detecting their magnetic fields. Our low-noise sapphire-based step-edge SQUIDs should be particularly suitable for such an application. An earlier effort to make SNS trench junctions using focused ion beam (FIB) is reviewed in a separate chapter. (Abstract shortened by UMI.)

Isotropic-resolution linear-array-based photoacoustic computed tomography through inverse Radon transform

NASA Astrophysics Data System (ADS)

Li, Guo; Xia, Jun; Li, Lei; Wang, Lidai; Wang, Lihong V.

2015-03-01

Linear transducer arrays are readily available for ultrasonic detection in photoacoustic computed tomography. They offer low cost, hand-held convenience, and conventional ultrasonic imaging. However, the elevational resolution of linear transducer arrays, which is usually determined by the weak focus of the cylindrical acoustic lens, is about one order of magnitude worse than the in-plane axial and lateral spatial resolutions. Therefore, conventional linear scanning along the elevational direction cannot provide high-quality three-dimensional photoacoustic images due to the anisotropic spatial resolutions. Here we propose an innovative method to achieve isotropic resolutions for three-dimensional photoacoustic images through combined linear and rotational scanning. In each scan step, we first elevationally scan the linear transducer array, and then rotate the linear transducer array along its center in small steps, and scan again until 180 degrees have been covered. To reconstruct isotropic three-dimensional images from the multiple-directional scanning dataset, we use the standard inverse Radon transform originating from X-ray CT. We acquired a three-dimensional microsphere phantom image through the inverse Radon transform method and compared it with a single-elevational-scan three-dimensional image. The comparison shows that our method improves the elevational resolution by up to one order of magnitude, approaching the in-plane lateral-direction resolution. In vivo rat images were also acquired.

Fabrication and Characterization of Magnetic Nanowires in Anodic Alumina

NASA Astrophysics Data System (ADS)

Xiao, Z. L.; Han, Y. R.; Wang, H. H.; Welp, U.; Kwok, W. K.; Crabtree, G. W.

2002-03-01

Magnetic nanowires (cobalt, iron and nickel) with diameters down to 20 nm have been fabricated by electrodeposition. Both commercial and home-made anodized aluminum oxide (AAO) membranes with nanochannel arrays were used as templates. The structure and magnetization hysteresis of the specimens with nanowires were investigated with scanning electron microscope (SEM) and superconducting quantum interference device (SQUID), respectively. Growth of nanowires with both aqueous and dimethylsulfoxide (DMSO) solutions was conducted and better quality nanowires were obtained with the organic DMSO solution. The influence of the diameter, the length and the separation of the nanochannels on the magnetization orientation was investigated in detail. Work supported by the US Department of Energy (DOE), BES-Materials Science, Contract No. W-31-109-ENG-38.

Small, Fast TES Microcalorimeters with Unprecedented X-ray Spectral Performance

NASA Technical Reports Server (NTRS)

Eckart, M. E.; Adams, J. S.; Bailey, C. N.; Bandler, S. R.; Chervenak, J. A.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Sadleir, J. E.;

Two-dimensional Magnetism in Arrays of Superconducting Rings

NASA Astrophysics Data System (ADS)

Reich, Daniel H.

1996-03-01

An array of superconducting rings in an applied field corresponding to a flux of Φ0 /2 per ring behaves like a 2D Ising antiferromagnet. Each ring has two energetically equivalent states with equal and opposite magnetic moments due to fluxoid quantization, and the dipolar coupling between rings favors antiparallel alignment of the moments. Using SQUID magnetometry and scanning Hall probe microscopy, we have studied the dynamics and magnetic configurations of micron-size aluminum rings on square, triangular, honeycomb, and kagomé lattices. We have found that there are significant antiferromagnetic correlations between rings, and that effects of geometrical frustration can be observed on the triangular and kagomé lattices. Long range correlations on the other lattices are suppressed by the analog of spin freezing that locks the rings in metastable states at low temperatures, and by quenched disorder due to imperfections in the fabrication. This disorder produces a roughly 1% variation in the rings' areas, which translates into an effective random field on the spins. The ring arrays are thus an extremely good realization of the 2D random-field Ising model. (Performed in collaboration with D. Davidović, S. Kumar, J. Siegel, S. B. Field, R. C. Tiberio, R. Hey, and K. Ploog.) (Supported by NSF grants DMR-9222541, and DMR-9357518, and by the David and Lucile Packard Foundation.)

Moving-Article X-Ray Imaging System and Method for 3-D Image Generation

NASA Technical Reports Server (NTRS)

Fernandez, Kenneth R. (Inventor)

2012-01-01

An x-ray imaging system and method for a moving article are provided for an article moved along a linear direction of travel while the article is exposed to non-overlapping x-ray beams. A plurality of parallel linear sensor arrays are disposed in the x-ray beams after they pass through the article. More specifically, a first half of the plurality are disposed in a first of the x-ray beams while a second half of the plurality are disposed in a second of the x-ray beams. Each of the parallel linear sensor arrays is oriented perpendicular to the linear direction of travel. Each of the parallel linear sensor arrays in the first half is matched to a corresponding one of the parallel linear sensor arrays in the second half in terms of an angular position in the first of the x-ray beams and the second of the x-ray beams, respectively.

Micro-Machined High-Frequency (80 MHz) PZT Thick Film Linear Arrays

PubMed Central

Zhou, Qifa; Wu, Dawei; Liu, Changgeng; Zhu, Benpeng; Djuth, Frank; Shung, K. Kirk

2010-01-01

This paper presents the development of a micro-machined high-frequency linear array using PZT piezoelectric thick films. The linear array has 32 elements with an element width of 24 μm and an element length of 4 mm. Array elements were fabricated by deep reactive ion etching of PZT thick films, which were prepared from spin-coating of PZT solgel composite. Detailed fabrication processes, especially PZT thick film etching conditions and a novel transferring-and-etching method, are presented and discussed. Array designs were evaluated by simulation. Experimental measurements show that the array had a center frequency of 80 MHz and a fractional bandwidth (−6 dB) of 60%. An insertion loss of −41 dB and adjacent element crosstalk of −21 dB were found at the center frequency. PMID:20889407

A Practical HTS SQUID Magnetometer System for NDI of Aircraft

DTIC Science & Technology

1994-01-10

based on present-day high Tc SQUIDs is feasible, and present a portable design cooled by a miniature cryocooler . In addition, a reevaluation of the basic...integration of this cryocooler with SQUIDs, is that there is no available electromagnetic field emission information. We did not find any for other types ...background signals. Third, there are several other types of cryocoolers , integrated or split, made of plastics available on the market. They will

Parametric Phase-Sensitive Detector Using Two-cell SQUID

DTIC Science & Technology

2010-08-01

an attenuator of -20 dB. The microwave was fed into the coplanar resonator by a coplanar capacitance of 9 fF, and corresponding response was coupled...transmission line between the two coupled coplanar capacitances . With a network analyzer, the resonant frequency was confirmed to be 8.985 GHz and the...microwave directional sensors based on two-cell SQUIDs. Two SQUID circuits with different values of McCumber parameter βc have been tested. Observed

Gradiometer Using Middle Loops as Sensing Elements in a Low-Field SQUID MRI System

NASA Technical Reports Server (NTRS)

Penanen, Konstantin; Hahn, Inseob; Ho Eom, Byeong

2009-01-01

A new gradiometer scheme uses middle loops as sensing elements in lowfield superconducting quantum interference device (SQUID) magnetic resonance imaging (MRI). This design of a second order gradiometer increases its sensitivity and makes it more uniform, compared to the conventional side loop sensing scheme with a comparable matching SQUID. The space between the two middle loops becomes the imaging volume with the enclosing cryostat built accordingly.

A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system.

PubMed

Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

2014-09-01

Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

[Determination of proximal chemical composition of squid (dosidicus gigas) and development of gel products].

PubMed

Abugoch, L; Guarda, A; Pérez, L M; Paredes, M P

1999-06-01

The good nutritional properties of meat from big squid (Dosidicus gigas) living on the Chilean coast, was determined through its proximal composition 70 cal/100 g fresh meat; 82.23 +/- 0.98% moisture; 15.32 +/- 0.93% protein; 1.31 +/- 0.12% ashes; 0.87 +/- 0.18% fat and 0.27% NNE (non-nitrogen extract). The big squid meat was used to develop a gel product which contained NaCl and TPP. It was necessary to use additives for gel preparation, such as carragenin or alginate or egg albumin, due to the lack of gelation properties of squid meat. Formulations containing egg albumin showed the highest gel force measured by penetration as compared to those that contained carragenin or alginate.

Conformational changes in proteins recovered from jumbo squid (Dosidicus gigas) muscle through pH shift washing treatments.

PubMed

Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Ramírez-Suárez, Juan C; Lugo-Sánchez, Maria E; García-Orozco, Karina D; Sotelo-Mundo, Rogerio R; Peña-Ramos, Aida

2016-04-01

Conformational and thermal-rheological properties of acidic (APC) and neutral (NPC) protein concentrates were evaluated and compared to those of squid (Dosidicus gigas) muscle proteins (SM). Surface hydrophobicity, sulfhydryl status, secondary structure profile, differential scanning calorimetry and oscillatory dynamic rheology were used to evaluate the effect of treatments on protein properties. Acidic condition during the washing process (APC) promoted structural and conformational changes in the protein present in the concentrate produced. These changes were enhanced during the heat setting of the corresponding sol. Results demonstrate that washing squid muscle under the proposed acidic conditions is a feasible technological alternative for squid-based surimi production improving its yield and gel-forming ability. Copyright © 2015. Published by Elsevier Ltd.

Radiofrequency amplifier based on a dc superconducting quantum interference device

DOEpatents

Hilbert, Claude; Martinis, John M.; Clarke, John

1986-01-01

A low noise radiofrequency amplifier (10), using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID (11) and an input coil (12) are maintained at superconductivity temperatures in a superconducting shield (13), with the input coil (12) inductively coupled to the superconducting ring (17) of the dc SQUID (11). A radiofrequency signal from outside the shield (13) is applied to the input coil (12), and an amplified radiofrequency signal is developed across the dc SQUID ring (17) and transmitted to exteriorly of the shield (13). A power gain of 19.5.+-.0.5 dB has been achieved with a noise temperature of 1.0.+-.0.4 K. at a frequency of 100 MHz.

Reliability of Central Adiposity Assessments Using B-Mode Ultrasound: A Comparison of Linear and Curved Array Transducers.

PubMed

Stoner, Lee; Geoffron, Morgane; Cornwall, Jon; Chinn, Victoria; Gram, Martin; Credeur, Daniel; Fryer, Simon

2016-12-01

Recently, it was reported that intra-abdominal thickness (IAT) assessments using ultrasound are most reliable if measured from the linea alba to the anterior vertebral column. These 2 anatomical sites can be simultaneously visualized using a linear array transducer. Linear array transducers have different operational characteristics when compared with conventional curved array transducers and are more reliable for some ultrasound-derived measures such as abdominal subcutaneous fat thickness. However, it is unknown whether linear array transducers facilitate more reliable IAT measurements than curved array transducers. The purpose of the current study was to (1) compare the reliability of linear and curved array transducer assessments of IAT and maximal abdominal ratio (MAR) and (2) use the findings to update central adiposity measurement guidelines. Fifteen healthy adults (mean [SD], 27 [10] years; 60% female) with a range of somatotypes (body mass index: mean [SD], 24 [4]; range, 19-33 kg/m; waist circumference: mean [SD], 75 [11]; range, 61-96 cm) were tested on 3 mornings under standardized conditions. Intra-abdominal thickness was assessed 2 cm above the umbilicus (transverse plane), measuring from linea alba to the anterior vertebral column. Maximal abdominal ratio was defined as the ratio of IAT to abdominal subcutaneous fat thickness. The IAT range was 25 to 87 mm, and the MAR range was 0.15 to 0.77. Between-day intraclass correlation coefficient values for IAT measurements made were comparable (0.96-0.97) for both transducers, as were MAR values (0.95). In conclusion, while both transducers provided equally reliable measurement of IAT, the use of a single linear array transducer simplifies the assessment of central adiposity.

Optimized Hyper Beamforming of Linear Antenna Arrays Using Collective Animal Behaviour

PubMed Central

Ram, Gopi; Mandal, Durbadal; Kar, Rajib; Ghoshal, Sakti Prasad

2013-01-01

A novel optimization technique which is developed on mimicking the collective animal behaviour (CAB) is applied for the optimal design of hyper beamforming of linear antenna arrays. Hyper beamforming is based on sum and difference beam patterns of the array, each raised to the power of a hyperbeam exponent parameter. The optimized hyperbeam is achieved by optimization of current excitation weights and uniform interelement spacing. As compared to conventional hyper beamforming of linear antenna array, real coded genetic algorithm (RGA), particle swarm optimization (PSO), and differential evolution (DE) applied to the hyper beam of the same array can achieve reduction in sidelobe level (SLL) and same or less first null beam width (FNBW), keeping the same value of hyperbeam exponent. Again, further reductions of sidelobe level (SLL) and first null beam width (FNBW) have been achieved by the proposed collective animal behaviour (CAB) algorithm. CAB finds near global optimal solution unlike RGA, PSO, and DE in the present problem. The above comparative optimization is illustrated through 10-, 14-, and 20-element linear antenna arrays to establish the optimization efficacy of CAB. PMID:23970843

Microstrip antenna developments at JPL

NASA Technical Reports Server (NTRS)

Huang, John

1991-01-01

The in-house development of microstrip antennas, initiated in 1981, when a spaceborne lightweight and low-profile planar array was needed for a satellite communication system, is described. The work described covers the prediction of finite-ground-plane effects by the geometric theory of diffraction, higher-order-mode circularly polarized circular patch antennas, circularly polarized microstrip arrays with linearly polarized elements, an impedance-matching teardrop-shaped probe feed, a dual-polarized microstrip array with high isolation and low cross-polarization, a planar microstrip Yagi array, a microstrip reflectarray, a Ka-band MMIC array, and a series-fed linear arrays.

Hafnium Films and Magnetic Shielding for TIME, A mm-Wavelength Spectrometer Array

NASA Astrophysics Data System (ADS)

Hunacek, J.; Bock, J.; Bradford, C. M.; Butler, V.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A.; Crites, A.; Frez, C.; Hailey-Dunsheath, S.; Hoscheit, B.; Kim, D. W.; Li, C.-T.; Marrone, D.; Moncelsi, L.; Shirokoff, E.; Steinbach, B.; Sun, G.; Trumper, I.; Turner, A.; Uzgil, B.; Weber, A.; Zemcov, M.

2018-04-01

TIME is a mm-wavelength grating spectrometer array that will map fluctuations of the 157.7-μm emission line of singly ionized carbon ([CII]) during the epoch of reionization (redshift z ˜ 5-9). Sixty transition-edge sensor (TES) bolometers populate the output arc of each of the 32 spectrometers, for a total of 1920 detectors. Each bolometer consists of gold absorber on a ˜ 3 × 3 mm silicon nitride micro-mesh suspended near the corners by 1 × 1 × 500 μm silicon nitride legs targeting a photon-noise-dominated NEP ˜ 1 × 10^{-17} W/√{Hz} . Hafnium films are explored as a lower-T_c alternative to Ti (500 mK) for TIME TESs, allowing thicker support legs for improved yield. Hf T_c is shown to vary between 250 and 450 mK when varying the resident Ar pressure during deposition. Magnetic shielding designs and simulations are presented for the TIME first-stage SQUIDs. Total axial field suppression is predicted to be 5 × 10^7.

Updates on the Transition-Edge Sensors and Multiplexed Readout for HOLMES

NASA Astrophysics Data System (ADS)

Puiu, A.; Becker, D.; Bennett, D.; Biasotti, M.; Borghesi, M.; Ceriale, V.; De Gerone, M.; Faverzani, M.; Ferri, E.; Fowler, J.; Gallucci, G.; Gard, J.; Hays-Wehle, J.; Hilton, G.; Giachero, A.; Mates, J.; Nucciotti, A.; Orlando, A.; Pessina, G.; Schmidt, D.; Swetz, D.; Ullom, J.; Vale, L.

2018-05-01

Measuring the neutrino mass is one of the most compelling issues in particle physics. HOLMES is an experiment for a direct measurement of the neutrino mass. HOLMES will perform a precise measurement of the end point of the electron capture decay spectrum of ^{163}Ho in order to extract information on the neutrino mass with a sensitivity as low as 1 eV. HOLMES, in its final configuration, will deploy a 1000-pixel array of low-temperature microcalorimeters: each calorimeter is made of an absorber, where the Ho atoms will be implanted, coupled to a transition-edge sensor (TES) thermometer. The detectors will be operated at the working temperature of 100 mK provided by a dilution refrigerator. In order to read out the 1000-detector array of HOLMES, a multiplexing system is necessary: the choice is to couple the transition-edge sensors to a multiplexed rf-SQUID. In this contribution we outline the progress made towards the final configuration of HOLMES regarding both the performances of the TES detectors and the characteristics of the multiplexing system.

Development of a TES-Based Anti-Coincidence Detector for Future X-Ray Observations

NASA Technical Reports Server (NTRS)

Bailey, Catherine N.; Adams, J. S.; Bandler, S. R.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Sadleir, J. E.;

Development of a TES-Based Anti-Coincidence Detector for Future X-ray Observatories

NASA Technical Reports Server (NTRS)

Bailey, Catherine

2011-01-01

Microcalorimeters onboard future x-ray observatories require an anti-coincidence detector to remove environmental backgrounds. In order to most effectively integrate this anticoincidence detector with the main microcalorimeter array, both instruments should use similar read-out technology. The detectors used in the Cryogenic Dark Matter Search (CDMS) use a phonon measurement technique that is well suited for an anti-coincidence detector with a microcalorimeter array using SQUID readout. This technique works by using a transition-edge sensor (TES) connected to superconducting collection fins to measure the athermal phonon signal produced when an event occurs in the substrate crystal. Energy from the event propagates through the crystal to the superconducting collection fins, creating quasiparticles, which are then trapped as they enter the TES where they produce a signal. We are currently developing a prototype anti-coincidence detector for future x-ray missions and have recently fabricated test devices with Mo/Au TESs and Al collection fins. We will present results from the first tests of these devices which indicate a proof of concept that quasiparticle trapping is occurring in these materials.

Comprehensive Model of Jumbo Squid Dosidicus gigas Trophic Ecology in the Northern Humboldt Current System

PubMed Central

Alegre, Ana; Ménard, Frédéric; Tafur, Ricardo; Espinoza, Pepe; Argüelles, Juan; Maehara, Víctor; Flores, Oswaldo; Simier, Monique; Bertrand, Arnaud

2014-01-01

The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters. PMID:24465788

Comprehensive model of Jumbo squid Dosidicus gigas trophic ecology in the Northern Humboldt current system.

PubMed

Alegre, Ana; Ménard, Frédéric; Tafur, Ricardo; Espinoza, Pepe; Argüelles, Juan; Maehara, Víctor; Flores, Oswaldo; Simier, Monique; Bertrand, Arnaud

2014-01-01

The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters.

Complex Visual Adaptations in Squid for Specific Tasks in Different Environments

PubMed Central

Chung, Wen-Sung; Marshall, N. Justin

2017-01-01

In common with their major competitors, the fish, squid are fast moving visual predators that live over a great range of depths in the ocean. Both squid and fish show a variety of adaptations with respect to optical properties, receptors and their underlying neural circuits, and these adaptations are often linked to the light conditions of their specific niche. In contrast to the extensive investigations of adaptive strategies in fish, vision in response to the varying quantity and quality of available light, our knowledge of visual adaptations in squid remains sparse. This study therefore undertook a comparative study of visual adaptations and capabilities in a number of squid species collected between 0 and 1,200 m. Histology, magnetic resonance imagery (MRI), and depth distributions were used to compare brains, eyes, and visual capabilities, revealing that the squid eye designs reflect the lifestyle and the versatility of neural architecture in its visual system. Tubular eyes and two types of regional retinal deformation were identified and these eye modifications are strongly associated with specific directional visual tasks. In addition, a combination of conventional and immuno-histology demonstrated a new form of a complex retina possessing two inner segment layers in two mid-water squid species which they rhythmically move across a broad range of depths (50–1,000 m). In contrast to their relatives with the regular single-layered inner segment retina live in the upper mesopelagic layer (50–400 m), the new form of retinal interneuronal layers suggests that the visual sensitivity of these two long distance vertical migrants may increase in response to dimmer environments. PMID:28286484

Non-resonant interactions between superconducting circuits coupled through a dc-SQUID

NASA Astrophysics Data System (ADS)

Jin, X. Y.; Lecocq, F.; Cicak, K.; Kotler, S. S.; Peterson, G. A.; Teufel, J. D.; Aumentado, J.; Simmonds, R. W.

We use a flux-biased direct current superconducting quantum interference device (dc-SQUID) to generate non-resonant tunable interactions between transmon qubits and resonators modes. By modulating the flux to the dc-SQUID, we can create an interaction with variable coupling rates from zero to greater than 100 MHz. We explore this system experimentally and describe its operation. Parametric coupling is important for constructing larger coupled systems, useful for both quantum information architectures and quantum simulators.

Behavioral ecology of jumbo squid (Dosidicus gigas) in relation to oxygen minimum zones

NASA Astrophysics Data System (ADS)

Stewart, Julia S.; Field, John C.; Markaida, Unai; Gilly, William F.

2013-10-01

Habitat utilization, behavior and food habits of the jumbo or Humboldt squid, Dosidicus gigas, were compared between an area recently inhabited in the northern California Current System (CCS) and a historically established area of residence in the Gulf of California (GOC). Low dissolved oxygen concentrations at midwater depths define the oxygen minimum zone (OMZ), an important environmental feature in both areas. We analyzed vertical diving behavior and diet of D. gigas and hydrographic properties of the water column to ascertain the extent to which squid utilized the OMZ in the two areas. The upper boundary of the OMZ has been shoaling in recent decades in the CCS, and this phenomenon has been proposed to vertically compress the pelagic environment inhabited by aerobic predators. A shoaling OMZ will also bring mesopelagic communities into a depth range with more illumination during daytime, making these organisms more vulnerable to predation by visual predators (i.e. jumbo squid). Because the OMZ in the GOC is considerably shallower than in the CCS, our study provides insight into the behavioral plasticity of jumbo squid and how they may respond to a shoaling OMZ in the CCS. We propose that shoaling OMZs are likely to be favorable to jumbo squid and could be a key indirect factor behind the recent range expansion of this highly migratory predator.

Investigation and optimization of low-frequency noise performance in readout electronics of dc superconducting quantum interference device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Jing; Peter Grünberg Institute; Zhang, Yi

2014-05-15

We investigated and optimized the low-frequency noise characteristics of a preamplifier used for readout of direct current superconducting quantum interference devices (SQUIDs). When the SQUID output was detected directly using a room-temperature low-voltage-noise preamplifier, the low-frequency noise of a SQUID system was found to be dominated by the input current noise of the preamplifiers in case of a large dynamic resistance of the SQUID. To reduce the current noise of the preamplifier in the low-frequency range, we investigated the dependence of total preamplifier noise on the collector current and source resistance. When the collector current was decreased from 8.4 mAmore » to 3 mA in the preamplifier made of 3 parallel SSM2220 transistor pairs, the low-frequency total voltage noise of the preamplifier (at 0.1 Hz) decreased by about 3 times for a source resistance of 30 Ω whereas the white noise level remained nearly unchanged. Since the relative contribution of preamplifier's input voltage and current noise is different depending on the dynamic resistance or flux-to-voltage transfer of the SQUID, the results showed that the total noise of a SQUID system at low-frequency range can be improved significantly by optimizing the preamplifier circuit parameters, mainly the collector current in case of low-noise bipolar transistor pairs.« less

Investigation and optimization of low-frequency noise performance in readout electronics of dc superconducting quantum interference device

NASA Astrophysics Data System (ADS)

Zhao, Jing; Zhang, Yi; Lee, Yong-Ho; Krause, Hans-Joachim

2014-05-01

We investigated and optimized the low-frequency noise characteristics of a preamplifier used for readout of direct current superconducting quantum interference devices (SQUIDs). When the SQUID output was detected directly using a room-temperature low-voltage-noise preamplifier, the low-frequency noise of a SQUID system was found to be dominated by the input current noise of the preamplifiers in case of a large dynamic resistance of the SQUID. To reduce the current noise of the preamplifier in the low-frequency range, we investigated the dependence of total preamplifier noise on the collector current and source resistance. When the collector current was decreased from 8.4 mA to 3 mA in the preamplifier made of 3 parallel SSM2220 transistor pairs, the low-frequency total voltage noise of the preamplifier (at 0.1 Hz) decreased by about 3 times for a source resistance of 30 Ω whereas the white noise level remained nearly unchanged. Since the relative contribution of preamplifier's input voltage and current noise is different depending on the dynamic resistance or flux-to-voltage transfer of the SQUID, the results showed that the total noise of a SQUID system at low-frequency range can be improved significantly by optimizing the preamplifier circuit parameters, mainly the collector current in case of low-noise bipolar transistor pairs.

Vestigial phragmocone in the gladius points to a deepwater origin of squid (Mollusca: Cephalopoda)

NASA Astrophysics Data System (ADS)

Arkhipkin, Alexander I.; Bizikov, Vyacheslav A.; Fuchs, Dirk

2012-03-01

The microstructure of the gladius cone was investigated in six species of nektonic squid: shallow-water Loligo gahi (Loliginidae), pelagic eurybathic Illex argentinus, Todarodes pacificus, Dosidicus gigas (Ommastrephidae), and deepwater Onykia ingens (Onychoteuthidae) and Gonatus antarcticus (Gonatidae) using state-of-the-art microscopy. Apart from L. gahi, all other species had septa-like layers in the gladius cone, which for the first time were investigated in detail and compared with those in extinct Cretaceous belemnites Hibolithes sp. and Pachyteuthis sp., and spirulid Cyrtobelus sp. It was found that the organic layers of the gladius cone in recent squid can be homologized with the organic components of the shell in fossil phragmocone-bearing coleoids. The septa-like layers in modern gladius cones therefore represent a vestigial phragmocone composed of organic septal rudiments of the ancestral phragmocone that has lost the siphuncle and gas-filled chambers. The well-developed rostrum in onychoteuthids and small rostrum of the gladius in ommastrephids and gonatids can be seen as homologous with the belemnoid rostrum, which may indicate a close phylogenetic relationship between belemnites and at least some squid. Possible evolutionary pathways of the reduction of the functional phragmocone in squid ancestors are discussed. Several features such as the loss of shell calcification, deep water speciation, and the structure of the equilibrium organ point to a deep-water origin of squids.

Development of a Cryostat to Characterize Nano-scale Superconducting Quantum Interference Devices

NASA Astrophysics Data System (ADS)

Longo, Mathew; Matheny, Matthew; Knudsen, Jasmine

2016-03-01

We have designed and constructed a low-noise vacuum cryostat to be used for the characterization of nano-scale superconducting quantum interference devices (SQUIDs). Such devices are very sensitive to magnetic fields and can measure changes in flux on the order of a single electron magnetic moment. As a part of the design process, we calculated the separation required between the cryogenic preamplifier and superconducting magnet, including a high-permeability magnetic shield, using a finite-element model of the apparatus. The cryostat comprises a vacuum cross at room temperature for filtered DC and shielded RF electrical connections, a thin-wall stainless steel support tube, a taper-sealed cryogenic vacuum can, and internal mechanical support and wiring for the nanoSQUID. The Dewar is modified with a room-temperature flange with a sliding seal for the cryostat. The flange supports the superconducting 3 Tesla magnet and thermometry wiring. Upon completion of the cryostat fabrication and Dewar modifications, operation of the nanoSQUIDs as transported from our collaborator's laboratory in Israel will be confirmed, as the lead forming the SQUID is sensitive to oxidation and the SQUIDs must be shipped in a vacuum container. After operation of the nanoSQUIDs is confirmed, the primary work of characterizing their high-speed properties will begin. This will include looking at the measurement of relaxation oscillations at high bandwidth in comparison to the theoretical predictions of the current model.

Y1Ba2Cu3O(7-delta) thin film dc SQUIDs (superconducting quantum interference device)

NASA Astrophysics Data System (ADS)

Racah, Daniel

1991-03-01

Direct current superconducting quantum interferometers (SQUIDs) based on HTSC thin films have been measured and characterized. The thin films used were of different quality: (1) Granular films on Sapphire substrates, prepared either by e-gun evaporation, by laser ablation or by MOCVD (metal oxide chemical vapor deposition), (2) Epitaxial films on MgO substrates. Modulations of the voltage on the SQUIDs as a function of the applied flux have been observed in a wide range of temperatures. The nature of the modulation was found to be strongly dependent on the morphology of the film and on its critical current. The SQUIDs based on granular films were relatively noisy, hysteretic and with a complicated V-phi shape. Those devices based on low quality (lowIc) granular films could be measured only at low temperatures (much lower than 77 K). While those of higher quality (granular films with high Ic) could be measured near to the superconductive transition. The SQUID based on high quality epitaxial film was measured near Tc and showed an anomalous, time dependent behavior.

Measurement of SQUID noise levels for SuperCDMS SNOLAB detectors - Final Paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Maxwell

SuperCDMS SNOLAB is a second generation direct dark matter search. In the SuperCDMS SNOLAB experiment, detectors are able to pick up from signals from dark matter nuclear recoil interactions which occur inside the bulk of the detectors. These interactions produce both phonon and charge signals. HEMTs read out charge signals whereas TES are used to detect phonon signals which are then read out by SQUID amplifiers. SQUID amplifiers must add negligible noise to the TES intrinsic noise which has been previously measured and is approximately 50pA/√Hz down to 100Hz for ease of signal distinguishability in dark matter nuclear interactions. Themore » intrinsic noise level of the SQUID was tested in the SLAC 300mK fridge and determined to provide adequately low levels of noise with a floor of approximately 3pA/√Hz. Furthermore, a 10x amplifier was tested for addition of extraneous noise. This noise was investigated with and without this amplifier, and it was found that it did not add a significant amount of noise to the intrinsic SQUID noise.« less

Flux Noise due to Spins in SQUIDs

NASA Astrophysics Data System (ADS)

LaForest, Stephanie

Superconducting Quantum Interference Devices (SQUIDs) are currently being used as flux qubits and read-out detectors in a variety of solid-state quantum computer architectures. The main limitation of SQUID qubits is that they have a coherence time of the order of 10 micros, due to the presence of intrinsic flux noise that is not yet fully understood. The origin of flux noise is currently believed to be related to spin impurities present in the materials and interfaces that form the device. Here we present a novel numerical method that enables calculations of the flux produced by spin impurities even when they are located quite close to the SQUID wire. We show that the SQUID will be particularly sensitive to spins located at its wire edges, generating flux shifts of up to 4 nano flux quanta, much higher than previous calculations based on the software package FastHenry. This shows that spin impurities in a particular region along the wire's surface play a much more important role in producing flux noise than other spin impurities located elsewhere in the device.

A 400 KHz line rate 2048-pixel stitched SWIR linear array

NASA Astrophysics Data System (ADS)

Anchlia, Ankur; Vinella, Rosa M.; Gielen, Daphne; Wouters, Kristof; Vervenne, Vincent; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; De Gaspari, Danny; Das, Jo; Merken, Patrick

2016-05-01

Xenics has developed a family of stitched SWIR long linear arrays that operate up to 400 KHz of line rate. These arrays serve medical and industrial applications that require high line rates as well as space applications that require long linear arrays. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long array to run at a high line rates irrespective of the array length, which limits the line rate in a traditional linear array. The ROIC is flip-chipped with InGaAs detector arrays. The FPA has a pixel pitch of 12.5μm and has two pixel flavors: square (12.5μm) and rectangular (250μm). The frontend circuit is based on Capacitive Trans-impedance Amplifier (CTIA) to attain stable detector bias, and good linearity and signal integrity, especially at high speeds. The CTIA has an input auto-zero mechanism that allows to have low detector bias (<20mV). An on-chip Correlated Double Sample (CDS) facilitates removal of CTIA KTC and 1/f noise, and other offsets, achieving low noise performance. There are five gain modes in the FPA giving the full well range from 85Ke- to 40Me-. The measured input referred noise is 35e-rms in the highest gain mode. The FPA operates in Integrate While Read mode and, at a master clock rate of 60MHz and a minimum integration time of 1.4μs, achieves the highest line rate of 400 KHz. In this paper, design details and measurements results are presented in order to demonstrate the array performance.

The Hawaiian bobtail squid as a model system for selective particle capture in microfluidic systems.

NASA Astrophysics Data System (ADS)

Nawroth, Janna; McFall-Ngai, Margaret; Dabiri, John

2013-11-01

Juvenile Hawaiian bobtail squids reliably capture and isolate a single species of bacteria, Vibrio fischeri, from inhaled coastal water containing a huge background of living and non-living particles of comparable size. Biochemical mechanisms orchestrate a chain of specific interactions as soon as V.fischeri attach to the squid's internal light organ. It remains unclear, however, how the bacteria carried by the squid's ventilation currents are initially attracted to the light organ's surface. Here we present preliminary experimental data showing how arrangement and coordination of the cilia covering the light organ create a 3D flow field that facilitates advection, sieving and selective retention of flow-borne particles. These studies may inspire novel microfluidic tools for detection and capture of specific cells and particles.

NMR/MRI with hyperpolarized gas and high Tc SQUID

DOEpatents

Schlenga, Klaus; de Souza, Ricardo E.; Wong-Foy, Annjoe; Clarke, John; Pines, Alexander

2000-01-01

A method and apparatus for the detection of nuclear magnetic resonance (NMR) signals and production of magnetic resonance imaging (MRI) from samples combines the use of hyperpolarized inert gases to enhance the NMR signals from target nuclei in a sample and a high critical temperature (Tc) superconducting quantum interference device (SQUID) to detect the NMR signals. The system operates in static magnetic fields of 3 mT or less (down to 0.1 mT), and at temperatures from liquid nitrogen (77K) to room temperature. Sample size is limited only by the size of the magnetic field coils and not by the detector. The detector is a high Tc SQUID magnetometer designed so that the SQUID detector can be very close to the sample, which can be at room temperature.

Fabrication and characterization of hybrid Nb-YBCO dc SQUIDs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frack, E.K.; Drake, R.E.; Patt, R.

This paper reports on the fabrication of hybrid low T{sub c}/high T{sub c} dc SQUIDs of two flavors. The first kind utilizes niobium tunnel junctions and a YBCO film strip as the most inductive portion of the SQUID loop. This configuration allows a direct measurement of the inductance of the YBCO microstrip from which the effective penetration depth can be calculated. The successful fabrication of these SQUIDs has required 1. superconducting Nb-to-YBCO contacts, 2. deposition and patterning of an SiO{sub 2} insulation layer over YBCO, and 3. selective patterning of niobium and SiO{sub 2} relative to YBCO. All these processmore » steps are pertinent to the eventual use of YBCO thin films in electronic devices.« less

A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob, E-mail: ihahn@caltech.edu

2014-09-15

Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas ofmore » further improvements needed to bring the imaging performance to parity with conventional MRI systems.« less

Development of RF Sensor Based on Two-Cell Squid

DTIC Science & Technology

2011-07-15

to (8) is proportional to the reduced drive detuning, ωp0 is the resonant frequency for small oscillations, i.e. the plasma frequency of the combined...2 Φ= cnc IRπω (16) where Rn is the normal resistance of the Josephson junction in the SQUID, and L the inductance of the...were about 9 fF. The critical current I0 of each junction in the SQUID was 17.7 μA, normal resistance 110.9 Ω, plasma frequency ωp 124 GHz and

Development of RF Sensor Based on Two-cell SQUID

DTIC Science & Technology

2012-07-01

according to (8) is proportional to the reduced drive detuning, ωp0 is the resonant frequency for small oscillations, i.e. the plasma frequency of the...0/2 Φ= cnc IRπω (16) where Rn is the normal resistance of the Josephson junction in the SQUID, and L the inductance of the...17.7 μA, normal resistance 110.9 Ω, plasma frequency ωp 124 GHz and characteristic frequency 948 GHz. While the loop inductance of SQUID was 60 pH

Basic and Applied Magnetism with a Squid Gradiometer.

DTIC Science & Technology

1985-12-01

r , , WV w- =v- -V,; . r Zr! I , : r -. : r , : s : i . : I , C CI SQUID ta) 0 7 - .- 4 , 4 4 4 - .44* . . 2 Te 1 I T ...... 2zt 14 tbt’faceewient...incheS) iuSteed D~ISPLACE4ENT ’ . • •. . , I t ( pi A, , I phud.I’ t h bh r . /Os ,7/,/( ds I DR8 _ I Is i it r V( ttw( lt hd ,h r % I I VS94 SQUID...magnetization. Barkhausen Reversible Missing

1976 Navy Study on Superconductive Electronics, August 2-13, 1976, Naval Postgraduate School, Monterey, California

DTIC Science & Technology

1976-01-01

excluded from this Study except as points of reference. The conclusions identify a number of relevant functional technology items which are of...SQUID 20 4.2 4.3 The RF SQUID and its associated circuitry and operating characteristics 22 Bulk point contact SQUID formed by...a point contact, a constriction or microbridge in a thin film ("Dayem Bridge"), an S-N-S junction (in which pairs move through a "normal" metal

The effect of dietary protein and lipid source on dorsal fin erosion in rainbow trout, Oncorhynchus mykiss

USGS Publications Warehouse

Barrows, F.T.; Lellis, W.A.

1999-01-01

A study was conducted to determine the effect of dietary protein and lipid source on dorsal fin erosion in rainbow trout. Seven diets were each fed to four replicate lots of 300 first-feeding fry cultured in 75 1 aluminum troughs for 8 weeks. Two basal diets were manufactured with approximately equal nutrient content, one using krill and squid meals and the other anchovy meal as the primary protein-containing ingredients. The meals used to manufacture the diets were separated into two fractions: lipid (ether-extractable); and protein/ash (non-ether-extractable) using a large soxhlet. The fractions were then recombined to create two additional diets; one containing anchovy protein/ash with krill/squid lipid, the other krill/squid protein/ash with fish lipid. A fifth diet recombined krill/squid protein/ash with krill/squid lipid to evaluate effects of the extraction process. Two additional treatments included a diet with a portion of the krill meal replaced by poultry by-product meal, and the basal anchovy meal diet supplemented with sodium, magnesium, and copper. Fish consuming diets containing anchovy meal as the primary protein source gained more weight (P < 0.05) than fish consuming krill/squid meal-based diets. Dorsal fin index (DFI, measured as mean dorsal fin height x 100/total fish length) was greater (P < 0.05) for fish consuming diets containing krill/squid meal protein/ash fraction (DFI = 9.9%-10.0%) than for fish consuming diets containing anchovy meal protein/ash fraction (DFI = 4.9%-5.3%), regardless of lipid source. Supplementation of the anchovy meal diet with sodium, magnesium, and copper improved (P < 0.05) DFI by approximately 20%, but not to the level supported by the krill/squid meal protein/ash fraction diets. The cost of the krill meal diet was reduced by inclusion of poultry by-product meal without affecting dorsal fin condition. These data indicate that the dietary agent contributing to dorsal fin erosion in rainbow trout is not present in the ether-extractable fraction of the diet, but rather in the protein or mineral fraction.

Extra Double-stranded RNA Binding Domain (dsRBD) in a Squid RNA Editing Enzyme Confers Resistance to High Salt Environment*

PubMed Central

Palavicini, Juan Pablo; Correa-Rojas, Rodrigo A.; Rosenthal, Joshua J. C.

2012-01-01

A-to-I RNA editing is particularly common in coding regions of squid mRNAs. Previously, we isolated a squid editing enzyme (sqADAR2) that shows a unique structural feature when compared with other ADAR2 family members: an additional double-stranded RNA (dsRNA) binding domain (dsRBD). Alternative splicing includes or excludes this motif, generating a novel or a conventional variant termed sqADAR2a and sqADAR2b, respectively. The extra dsRBD of sqADAR2a increases its editing activity in vitro. We hypothesized that the high activity is due to an increase in the affinity of the enzyme for dsRNA. This may be important because protein-RNA interactions can be influenced by physical factors. We became particularly interested in analyzing the effects of salt on interactions between sqADAR2 and RNA because squid cells have a ∼3-fold higher ionic strength and proportionally more Cl− than vertebrate cells. To date, in vitro biochemical analyses of adenosine deamination have been conducted using vertebrate-like ionic strength buffers containing chloride as the major anion, although the vast majority of cellular anions are known to be organic. We found that squid-like salt conditions severely impair the binding affinity of conventional ADAR2s for dsRNA, leading to a decrease in nonspecific and site-specific editing activity. Inhibition of editing was mostly due to high Cl− levels and not to the high concentrations of K+, Na+, and organic anions like glutamate. Interestingly, the extra dsRBD in sqADAR2a conferred resistance to the high Cl− levels found in squid neurons. It does so by increasing the affinity of sqADAR2 for dsRNA by 30- or 100-fold in vertebrate-like or squid-like conditions, respectively. Site-directed mutagenesis of squid ADAR2a showed that its increased affinity and editing activity are directly attributable to the RNA binding activity of the extra dsRBD. PMID:22457361

Magnetic biosensor using a high transition temperature SQUID

NASA Astrophysics Data System (ADS)

Grossman, Helene Lila

A high transition temperature (Tc) Superconducting QUantum Interference Device (SQUID) is used to detect magnetically-labeled microorganisms. The targets are identified and quantified by means of magnetic relaxation measurements, with no need for unbound magnetic labels to be washed away. The binding rate between antibody-linked magnetic particles and targets can be measured with this technique. Installed in a "SQUID microscope," a YBa2Cu 3O7-delta SQUID is mounted on a sapphire rod thermally linked to a liquid nitrogen can; these components are enclosed in a fiberglass vacuum chamber. A thin window separates the vacuum chamber from the sample, which is at room temperature and atmospheric pressure. In one mode of the experiment, targets are immobilized on a substrate and immersed a suspension of ˜50 nm diameter superparamagnetic particles, coated with antibodies. A pulsed magnetic field aligns the magnetic dipole moments, and the SQUID measures the magnetic relaxation signal each time the field is turned off. Unbound particles relax within ˜50 mus by Brownian rotation, too fast for the SQUID system to measure. In contrast, particles bound to targets have their Brownian motion inhibited. These particles relax in ˜1 s by rotation of the internal dipole moment, and this Neel relaxation process is detected by the SQUID. This assay is demonstrated with a model system of liposomes carrying the FLAG epitope; the detection limit is (2.7 +/- 0.2) x 105 particles. The replacement of the SQUID with a gradiometer improves the detection limit to (7.0 +/- 0.7) x 103 particles. In an alternate mode of the experiment, freely suspended targets (larger than ˜1 mum diameter) are detected. Since the Brownian relaxation time of the targets is longer than the measurement time, particles bound to targets are effectively immobilized and exhibit Neel relaxation. Listeria monocytogenes are detected using this method; the sensitivity is (1.1 +/- 0.2) x 105 bacteria in 20 muL. For a 1 nL sample volume, the detection limit is expected to be 230 +/- 40 bacteria. Time-resolved measurements, which yield the binding rate between particles and bacteria, are reported. Also, potential improvements to the system and possible applications are discussed.

Design, Fabrication and Characterization of A Bi-Frequency Co-Linear Array

PubMed Central

Wang, Zhuochen; Li, Sibo; Czernuszewicz, Tomasz J; Gallippi, Caterina M.; Liu, Ruibin; Geng, Xuecang

2016-01-01

Ultrasound imaging with high resolution and large penetration depth has been increasingly adopted in medical diagnosis, surgery guidance, and treatment assessment. Conventional ultrasound works at a particular frequency, with a −6 dB fractional bandwidth of ~70 %, limiting the imaging resolution or depth of field. In this paper, a bi-frequency co-linear array with resonant frequencies of 8 MHz and 20 MHz was investigated to meet the requirements of resolution and penetration depth for a broad range of ultrasound imaging applications. Specifically, a 32-element bi-frequency co-linear array was designed and fabricated, followed by element characterization and real-time sectorial scan (S-scan) phantom imaging using a Verasonics system. The bi-frequency co-linear array was tested in four different modes by switching between low and high frequencies on transmit and receive. The four modes included the following: (1) transmit low, receive low, (2) transmit low, receive high, (3) transmit high, receive low, (4) transmit high, receive high. After testing, the axial and lateral resolutions of all modes were calculated and compared. The results of this study suggest that bi-frequency co-linear arrays are potential aids for wideband fundamental imaging and harmonic/sub-harmonic imaging. PMID:26661069

Analysis of the tenderisation of jumbo squid (Dosidicus gigas) meat by ultrasonic treatment using response surface methodology.

PubMed

Hu, Yaqin; Yu, Hiaxia; Dong, Kaicheng; Yang, Shuibing; Ye, Xingqian; Chen, Shiguo

2014-10-01

Due to its unique structure, jumbo squid (Dosidicus gigas) meat is sensitive to heat treatment, which makes the traditional squid products taste tough and hard. This study aimed to tenderise jumbo squid meat through ultrasonic treatment. Response surface methodology (RSM) was used to predict the tenderising effect of various treatment conditions. According to the results of RSM, the optimal conditions appeared to be a power of 186.9 W, a frequency of 25.6 kHz, and a time of 30.8 min, and the predicted values of flexibility and firmness under these optimal conditions were 2.40 mm and 435.1 g, respectively. Protein degradation and a broken muscle fibre structure were observed through histological assay and SDS-PAGE, which suggests a satisfactory tenderisation effect. Copyright © 2014. Published by Elsevier Ltd.

Operational Experience with the Frontier System in CMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blumenfeld, Barry; Dykstra, Dave; Kreuzer, Peter

2012-06-20

The Frontier framework is used in the CMS experiment at the LHC to deliver conditions data to processing clients worldwide, including calibration, alignment, and configuration information. Each central server at CERN, called a Frontier Launchpad, uses tomcat as a servlet container to establish the communication between clients and the central Oracle database. HTTP-proxy Squid servers, located close to clients, cache the responses to queries in order to provide high performance data access and to reduce the load on the central Oracle database. Each Frontier Launchpad also has its own reverse-proxy Squid for caching. The three central servers have been deliveringmore » about 5 million responses every day since the LHC startup, containing about 40 GB data in total, to more than one hundred Squid servers located worldwide, with an average response time on the order of 10 milliseconds. The Squid caches deployed worldwide process many more requests per day, over 700 million, and deliver over 40 TB of data. Several monitoring tools of the tomcat log files, the accesses of the Squids on the central Launchpad servers, and the availability of remote Squids have been developed to guarantee the performance of the service and make the system easily maintainable. Following a brief introduction of the Frontier framework, we describe the performance of this highly reliable and stable system, detail monitoring concerns and their deployment, and discuss the overall operational experience from the first two years of LHC data-taking.« less

The effect of phosphorylation on arrestin-rhodopsin interaction in the squid visual system.

PubMed

Robinson, Kelly A; Ou, Wei-Lin; Guan, Xinyu; Sugamori, Kim S; Bandyopadhyay, Abhishek; Ernst, Oliver P; Mitchell, Jane

2015-12-01

Invertebrate visual opsins are G protein-coupled receptors coupled to retinoid chromophores that isomerize reversibly between inactive rhodopsin and active metarhodopsin upon absorption of photons of light. The squid visual system has an arrestin protein that binds to metarhodopsin to block signaling to Gq and activation of phospholipase C. Squid rhodopsin kinase (SQRK) can phosphorylate both metarhodopsin and arrestin, a dual role that is unique among the G protein-coupled receptor kinases. The sites and role of arrestin phosphorylation by SQRK were investigated here using recombinant proteins. Arrestin was phosphorylated on serine 392 and serine 397 in the C-terminus. Unphosphorylated arrestin bound to metarhodopsin and phosphorylated metarhodopsin with similar high affinities (Kd 33 and 21 nM respectively), while phosphorylation of arrestin reduced the affinity 3- to 5-fold (Kd 104 nM). Phosphorylation of metarhodopsin slightly increased the dissociation of arrestin observed during a 1 hour incubation. Together these studies suggest a unique role for SQRK in phosphorylating both receptor and arrestin and inhibiting the binding of these two proteins in the squid visual system. Invertebrate visual systems are inactivated by arrestin binding to metarhodopsin that does not require receptor phosphorylation. Here we show that squid rhodopsin kinase phosphorylates arrestin on two serines (S392,S397) in the C-terminus and phosphorylation decreases the affinity of arrestin for squid metarhodopsin. Metarhodopsin phosphorylation has very little effect on arrestin binding but does increase arrestin dissociation. © 2015 International Society for Neurochemistry.

Operational Experience with the Frontier System in CMS

NASA Astrophysics Data System (ADS)

Blumenfeld, Barry; Dykstra, Dave; Kreuzer, Peter; Du, Ran; Wang, Weizhen

2012-12-01

The Frontier framework is used in the CMS experiment at the LHC to deliver conditions data to processing clients worldwide, including calibration, alignment, and configuration information. Each central server at CERN, called a Frontier Launchpad, uses tomcat as a servlet container to establish the communication between clients and the central Oracle database. HTTP-proxy Squid servers, located close to clients, cache the responses to queries in order to provide high performance data access and to reduce the load on the central Oracle database. Each Frontier Launchpad also has its own reverse-proxy Squid for caching. The three central servers have been delivering about 5 million responses every day since the LHC startup, containing about 40 GB data in total, to more than one hundred Squid servers located worldwide, with an average response time on the order of 10 milliseconds. The Squid caches deployed worldwide process many more requests per day, over 700 million, and deliver over 40 TB of data. Several monitoring tools of the tomcat log files, the accesses of the Squids on the central Launchpad servers, and the availability of remote Squids have been developed to guarantee the performance of the service and make the system easily maintainable. Following a brief introduction of the Frontier framework, we describe the performance of this highly reliable and stable system, detail monitoring concerns and their deployment, and discuss the overall operational experience from the first two years of LHC data-taking.

Vector sensor for scanning SQUID microscopy

NASA Astrophysics Data System (ADS)

Dang, Vu The; Toji, Masaki; Thanh Huy, Ho; Miyajima, Shigeyuki; Shishido, Hiroaki; Hidaka, Mutsuo; Hayashi, Masahiko; Ishida, Takekazu

2017-07-01

We plan to build a novel 3-dimensional (3D) scanning SQUID microscope with high sensitivity and high spatial resolution. In the system, a vector sensor consists of three SQUID sensors and three pick-up coils realized on a single chip. Three pick-up coils are configured in orthogonal with each other to measure the magnetic field vector of X, Y, Z components. We fabricated some SQUID chips with one uniaxial pick-up coil or three vector pick-up coils and carried out fundamental measurements to reveal the basic characteristics. Josephson junctions (JJs) of sensors are designed to have the critical current density J c of 320 A/cm2, and the critical current I c becomes 12.5 μA for the 2.2μm × 2.2μm JJ. We carefully positioned the three pickup coils so as to keep them at the same height at the centers of all three X, Y and Z coils. This can be done by arranging them along single line parallel to a sample surface. With the aid of multilayer technology of Nb-based fabrication, we attempted to reduce an inner diameter of the pickup coils to enhance both sensitivity and spatial resolution. The method for improving a spatial resolution of a local magnetic field image is to employ an XYZ piezo-driven scanner for controlling the positions of the pick-up coils. The fundamental characteristics of our SQUID sensors confirmed the proper operation of our SQUID sensors and found a good agreement with our design parameters.

Study of Far—Field Directivity Pattern for Linear Arrays

NASA Astrophysics Data System (ADS)

Ana-Maria, Chiselev; Luminita, Moraru; Laura, Onose

2011-10-01

A model to calculate directivity pattern in far field is developed in this paper. Based on this model, the three-dimensional beam pattern is introduced and analyzed in order to investigate geometric parameters of linear arrays and their influences on the directivity pattern. Simulations in azimuthal plane are made to highlight the influence of transducers parameters, including number of elements and inter-element spacing. It is true that these parameters are important factors that influence the directivity pattern and the appearance of side-lobes for linear arrays.

An ANSERLIN array for mobile satellite applications

NASA Technical Reports Server (NTRS)

Colomb, F. Y.; Kunkee, D. B.; Mayes, P. E.; Smith, D. W.; Jamnejad, V.

1990-01-01

Design, analysis, construction, and test of linear arrays of ANSERLIN (annular sector, radiating line) elements are reported and discussed. Due to feeding simplicity and easy construction as well as good CP performance, a planar array composed of a number of such linear arrays each producing a shaped beam tilted in elevation, is a good candidate as a vehicle-mounted mechanically steered antenna for mobile satellite applications. A single level construction technique was developed that makes this type of array very cost competitive with other low-profile arrays. An asymmetric 19.5 inch long four-element array was fabricated and tested with reasonable performance. A smaller five-element symmetric array (16 inch long) was also designed and tested capable of operating in either sense of circular polarization. Efforts were made to successfully reduce this effect.

Microfabricated linear Paul-Straubel ion trap

DOEpatents

Mangan, Michael A [Albuquerque, NM; Blain, Matthew G [Albuquerque, NM; Tigges, Chris P [Albuquerque, NM; Linker, Kevin L [Albuquerque, NM

2011-04-19

An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

Integration of a Cryocooler into a SQUID Magnetospinography System for Reduction of Liquid Helium Consumption

NASA Astrophysics Data System (ADS)

Adachi, Yoshiaki; Oyama, Daisuke; Kawai, Jun; Ogata, Hisanao; Uehara, Gen

We are currently developing a magnetospinography (MSG) system for noninvasive functional imaging of the spinal cord. The MSG system is a device for observing a weak magnetic field accompanied by the neural activity of the spinal cord by using an array of low-temperature superconducting quantum interference device (SQUID) magnetic flux sensors. As in the case of other biomagnetic measurement systems such as the magnetoencephalography (MEG) system, the running cost of the MSG system is mainly dependent on the liquid helium (LHe) consumption of a dewar vessel. We integrated a cryocooler into the MSG system to reduce LHe consumption. A pulse tube cryocooler with a cooling power of 0.5Wat 4 K was placed adjacent to a magnetically shielded room and was directly connected to the thermal radiation shield of the dewar by an electrically isolated transfer tube. Cold helium gas was circulated between the cryocooler and the radiation shield. Consequently, the temperature of the radiation shield decreased below 40 K. Previous studies have shown that the detection of a weak magnetic field is often hindered by severe low-frequency band noise from the cryocooler. However, the band of the MSG signals is much higher than that of the cryocooler noise. Therefore, the noise can be filtered out and has a less detrimental effect on MSG measurement than on other biomagnetic field measurements such as MEG measurement. As a result, LHe consumption was reduced by 46%, with no increase in the noise floor.

Adiabatic Demagnetization Refrigerator Field Mapping and Shielding Models for a 70 mK Superconducting Transition Edge Sensor Array and Associated Electronics

NASA Astrophysics Data System (ADS)

Ladner, D. R.; Martinez-Galarce, D. S.; McCammon, D.

2006-04-01

An X-ray detection instrument to be flown on a sounding rocket experiment (the Advanced Technology Solar Spectroscopic Imager - ATSSI) for solar physics observations is being developed by the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL). The detector is a novel class of microcalorimeter, a superconducting Transition-Edge Sensor (TES), that coupled with associated SQUID and feedback electronics requires high temperature stability at ~70 mK to resolve the energy of absorbed X-ray photons emitted from the solar corona. The cooling system incorporates an existing Adiabatic Demagnetization Refrigerator (ADR) developed at the University of Wisconsin (UW), which was previously flown to study the diffuse cosmic X-ray background. The Si thermistor detectors for that project required 130 K shielded JFET electronic components that are much less sensitive to the external field of the ADR solenoid than are the 1st (~70 mK) and 2nd (~2 K) SQUID stages used with TESs for solar observations. Modification of the Wisconsin ADR design, including TES focal plane and electronics re-positioning, therefore requires a tradeoff between the existing ADR solenoid nulling coil geometry and a low mass passive solenoid shield, while preserving the vibration isolation features of the existing design. We have developed models to accurately compute the magnetic field with and without shielding or nulling coils at critical locations to guide the re-design of the detector subsystem. The models and their application are described.

Toward Large Field-of-View High-Resolution X-ray Imaging Spectrometers: Microwave Multiplexed Readout of 28 TES Microcalorimeters

NASA Astrophysics Data System (ADS)

Yoon, W.; Adams, J. S.; Bandler, S. R.; Becker, D.; Bennett, D. A.; Chervenak, J. A.; Datesman, A. M.; Eckart, M. E.; Finkbeiner, F. M.; Fowler, J. W.; Gard, J. D.; Hilton, G. C.; Kelley, R. L.; Kilbourne, C. A.; Mates, J. A. B.; Miniussi, A. R.; Moseley, S. H.; Noroozian, O.; Porter, F. S.; Reintsema, C. D.; Sadleir, J. E.; Sakai, K.; Smith, S. J.; Stevenson, T. R.; Swetz, D. S.; Ullom, J. N.; Vale, L. R.; Wakeham, N. A.; Wassell, E. J.; Wollack, E. J.

2018-04-01

We performed small-scale demonstrations at GSFC of high-resolution X-ray TES microcalorimeters read out using a microwave SQUID multiplexer. This work is part of our effort to develop detector and readout technologies for future space-based X-ray instruments such as the microcalorimeter spectrometer envisaged for Lynx, a large mission concept under development for the Astro 2020 Decadal Survey. In this paper we describe our experiment, including details of a recently designed, microwave-optimized low-temperature setup that is thermally anchored to the 55 mK stage of our laboratory ADR. Using a ROACH2 FPGA at room temperature, we read out pixels of a GSFC-built detector array via a NIST-built multiplexer chip with Nb coplanar waveguide resonators coupled to rf-SQUIDs. The resonators are spaced 6 MHz apart (at ˜ 5.9 GHz) and have quality factors of ˜ 15,000. In our initial demonstration, we used flux-ramp modulation frequencies of 125 kHz to read out 5 pixels simultaneously and achieved spectral resolutions of 2.8-3.1 eV FWHM at 5.9 keV. Our subsequent work is ongoing: to-date we have achieved a median spectral resolution of 3.4 eV FWHM at 5.9 keV while reading out 28 pixels simultaneously with flux-ramp frequencies of 160 kHz. We present the measured system-level noise and maximum slew rates and briefly describe our future development work.

Jet Noise Source Localization Using Linear Phased Array

NASA Technical Reports Server (NTRS)

Agboola, Ferni A.; Bridges, James

2004-01-01

A study was conducted to further clarify the interpretation and application of linear phased array microphone results, for localizing aeroacoustics sources in aircraft exhaust jet. Two model engine nozzles were tested at varying power cycles with the array setup parallel to the jet axis. The array position was varied as well to determine best location for the array. The results showed that it is possible to resolve jet noise sources with bypass and other components separation. The results also showed that a focused near field image provides more realistic noise source localization at low to mid frequencies.

Magnetic relaxometry as applied to sensitive cancer detection and localization

DOE PAGES

De Haro, Leyma P.; Karaulanov, Todor; Vreeland, Erika C.; ...

2015-06-02

Abstract Here we describe superparamagnetic relaxometry (SPMR), a technology that utilizes highly sensitive magnetic sensors and superparamagnetic nanoparticles for cancer detection. Using SPMR, we sensitively and specifically detect nanoparticles conjugated to biomarkers for various types of cancer. SPMR offers high contrast In SPMR measurements, a brief magnetizing pulse is used to align superparamagnetic nanoparticles of a discrete size. Following the pulse, an array of superconducting quantum interference detectors (SQUID) sensors detect the decaying magnetization field. NP size is chosen so that, when bound, the induced field decays in seconds. They are functionalized with specific biomarkers and incubated with cancer cellsmore » As a result, superparamagnetic NPs developed here have small size dispersion. Cell incubation studies measure specificity for different cell lines and antibodies with very high contrast.« less

Iterative color-multiplexed, electro-optical processor.

PubMed

Psaltis, D; Casasent, D; Carlotto, M

1979-11-01

A noncoherent optical vector-matrix multiplier using a linear LED source array and a linear P-I-N photodiode detector array has been combined with a 1-D adder in a feedback loop. The resultant iterative optical processor and its use in solving simultaneous linear equations are described. Operation on complex data is provided by a novel color-multiplexing system.

Multiband selection with linear array detectors

NASA Technical Reports Server (NTRS)

Richard, H. L.; Barnes, W. L.

1985-01-01

Several techniques that can be used in an earth-imaging system to separate the linear image formed after the collecting optics into the desired spectral band are examined. The advantages and disadvantages of the Multispectral Linear Array (MLA) multiple optics, the MLA adjacent arrays, the imaging spectrometer, and the MLA beam splitter are discussed. The beam-splitter design approach utilizes, in addition to relatively broad spectral region separation, a movable Multiband Selection Device (MSD), placed between the exit ports of the beam splitter and a linear array detector, permitting many bands to be selected. The successful development and test of the MSD is described. The device demonstrated the capacity to provide a wide field of view, visible-to-near IR/short-wave IR and thermal IR capability, and a multiplicity of spectral bands and polarization measuring means, as well as a reasonable size and weight at minimal cost and risk compared to a spectrometer design approach.

Fiber bundle phase conjugate mirror

DOEpatents

Ward, Benjamin G.

2012-05-01

An improved method and apparatus for passively conjugating the phases of a distorted wavefronts resulting from optical phase mismatch between elements of a fiber laser array are disclosed. A method for passively conjugating a distorted wavefront comprises the steps of: multiplexing a plurality of probe fibers and a bundle pump fiber in a fiber bundle array; passing the multiplexed output from the fiber bundle array through a collimating lens and into one portion of a non-linear medium; passing the output from a pump collection fiber through a focusing lens and into another portion of the non-linear medium so that the output from the pump collection fiber mixes with the multiplexed output from the fiber bundle; adjusting one or more degrees of freedom of one or more of the fiber bundle array, the collimating lens, the focusing lens, the non-linear medium, or the pump collection fiber to produce a standing wave in the non-linear medium.

Effect of dietary marine lipids on female white bass ova compositions and progeny survival.

PubMed

Lewis, H A; Trushenski, J T; Lane, R L; Kohler, C C

2010-12-01

We evaluated white bass ovum fatty acid composition as well as embryonic and larval survival after varying n-3 and n-6 long-chain polyunsaturated fatty acid (LC-PUFA) concentrations in maternal diets. Diets containing graded levels (0, 33, 66, or 100%) of squid to menhaden oils were fed daily to apparent satiation to female white bass for 8 weeks prior to spawning. Embryonic survival was negatively related to maternal squid oil intake (P=0.015, R2=0.970). Squid oil-fed broodstock produced ova with decreased 20:5n-3 and increased C18 polyunsaturated fatty acid concentrations, largely reflecting the fatty acid profile of squid oil. Within ovum phospholipid, accumulation of 18:2n-6 may have altered biological function resulting in the lower embryonic survival among ova produced from the squid oil-fed broodstock. Our data suggest the importance of feeding white bass broodstock diets high in total n-3 LC-PUFA (at least 4.0% dry matter), and 20:5n-3-rich lipid sources such as menhaden oil can be effectively utilized by female white bass to produce quality ova.

Vampire squid: detritivores in the oxygen minimum zone

PubMed Central

Hoving, Hendrik J. T.; Robison, Bruce H.

2012-01-01

Vampire squid (Vampyroteuthis infernalis) are considered phylogenetic relics with cephalopod features of both octopods and squids. They lack feeding tentacles, but in addition to their eight arms, they have two retractile filaments, the exact functions of which have puzzled scientists for years. We present the results of investigations on the feeding ecology and behaviour of Vampyroteuthis, which include extensive in situ, deep-sea video recordings from MBARI's remotely operated vehicles (ROVs), laboratory feeding experiments, diet studies and morphological examinations of the retractile filaments, the arm suckers and cirri. Vampire squid were found to feed on detrital matter of various sizes, from small particles to larger marine aggregates. Ingested items included the remains of gelatinous zooplankton, discarded larvacean houses, crustacean remains, diatoms and faecal pellets. Both ROV observations and laboratory experiments led to the conclusion that vampire squid use their retractile filaments for the capture of food, supporting the hypothesis that the filaments are homologous to cephalopod arms. Vampyroteuthis' feeding behaviour is unlike any other cephalopod, and reveals a unique adaptation that allows these animals to spend most of their life at depths where oxygen concentrations are very low, but where predators are few and typical cephalopod food is scarce. PMID:23015627

Vampire squid: detritivores in the oxygen minimum zone.

PubMed

Hoving, Hendrik J T; Robison, Bruce H

2012-11-22

Vampire squid (Vampyroteuthis infernalis) are considered phylogenetic relics with cephalopod features of both octopods and squids. They lack feeding tentacles, but in addition to their eight arms, they have two retractile filaments, the exact functions of which have puzzled scientists for years. We present the results of investigations on the feeding ecology and behaviour of Vampyroteuthis, which include extensive in situ, deep-sea video recordings from MBARI's remotely operated vehicles (ROVs), laboratory feeding experiments, diet studies and morphological examinations of the retractile filaments, the arm suckers and cirri. Vampire squid were found to feed on detrital matter of various sizes, from small particles to larger marine aggregates. Ingested items included the remains of gelatinous zooplankton, discarded larvacean houses, crustacean remains, diatoms and faecal pellets. Both ROV observations and laboratory experiments led to the conclusion that vampire squid use their retractile filaments for the capture of food, supporting the hypothesis that the filaments are homologous to cephalopod arms. Vampyroteuthis' feeding behaviour is unlike any other cephalopod, and reveals a unique adaptation that allows these animals to spend most of their life at depths where oxygen concentrations are very low, but where predators are few and typical cephalopod food is scarce.

Rapid Associative Learning and Stable Long-Term Memory in the Squid Euprymna scolopes.

PubMed

Zepeda, Emily A; Veline, Robert J; Crook, Robyn J

2017-06-01

Learning and memory in cephalopod molluscs have received intensive study because of cephalopods' complex behavioral repertoire and relatively accessible nervous systems. While most of this research has been conducted using octopus and cuttlefish species, there has been relatively little work on squid. Euprymna scolopes Berry, 1913, a sepiolid squid, is a promising model for further exploration of cephalopod cognition. These small squid have been studied in detail for their symbiotic relationship with bioluminescent bacteria, and their short generation time and successful captive breeding through multiple generations make them appealing models for neurobiological research. However, little is known about their behavior or cognitive ability. Using the well-established "prawn-in-the-tube" assay of learning and memory, we show that within a single 10-min trial E. scolopes learns to inhibit its predatory behavior, and after three trials it can retain this memory for at least 12 d. Rapid learning and very long-term retention were apparent under two different training schedules. To our knowledge, this study is the first demonstration of learning and memory in this species as well as the first demonstration of associative learning in any squid.

Cold SQUIDs and hot samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, T.S.C.

1997-05-01

Low transition temperature (low-{Tc}) and high-{Tc} Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-{Tc} superconductors using two low-{Tc} SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied magneticmore » field, such that vortex-vortex interactions were unimportant, and with zero external current. At specific temperatures, the authors observed highly-correlated noise sources, suggesting that the vortices moved as rigid rods. At other temperatures, the noise was mostly uncorrelated, suggesting that the relevant vortices were pinned at more than one point along their length. Part 2 describes the design, construction, performance, and applications of a scanning high-{Tc} SQUID microscope optimized for imaging room-temperature objects with very high spatial resolution and magnetic source sensitivity.« less

Magnetization reversal of an individual exchange-biased permalloy nanotube

NASA Astrophysics Data System (ADS)

Buchter, A.; Wölbing, R.; Wyss, M.; Kieler, O. F.; Weimann, T.; Kohlmann, J.; Zorin, A. B.; Rüffer, D.; Matteini, F.; Tütüncüoglu, G.; Heimbach, F.; Kleibert, A.; Fontcuberta i Morral, A.; Grundler, D.; Kleiner, R.; Koelle, D.; Poggio, M.

2015-12-01

We investigate the magnetization reversal mechanism in an individual permalloy (Py) nanotube (NT) using a hybrid magnetometer consisting of a nanometer-scale SQUID (nanoSQUID) and a cantilever torque sensor. The Py NT is affixed to the tip of a Si cantilever and positioned in order to optimally couple its stray flux into a Nb nanoSQUID. We are thus able to measure both the NT's volume magnetization by dynamic cantilever magnetometry and its stray flux using the nanoSQUID. We observe a training effect and a temperature dependence in the magnetic hysteresis, suggesting an exchange bias. We find a low blocking temperature TB=18 ±2 K, indicating the presence of a thin antiferromagnetic native oxide, as confirmed by x-ray absorption spectroscopy on similar samples. Furthermore, we measure changes in the shape of the magnetic hysteresis as a function of temperature and increased training. These observations show that the presence of a thin exchange-coupled native oxide modifies the magnetization reversal process at low temperatures. Complementary information obtained via cantilever and nanoSQUID magnetometry allows us to conclude that, in the absence of exchange coupling, this reversal process is nucleated at the NT's ends and propagates along its length as predicted by theory.

The Stationary SQUID

NASA Astrophysics Data System (ADS)

Berger, Jorge

2018-06-01

In the customary mode of operation of a SQUID, the electromagnetic field in the SQUID is an oscillatory function of time. In this situation, electromagnetic radiation is emitted and couples to the sample. This is a back action that can alter the state that we intend to measure. A circuit that could perform as a stationary SQUID consists of a loop of superconducting material that encloses the magnetic flux, connected to a superconducting and to a normal electrode. This circuit does not contain Josephson junctions, or any other miniature feature. We study the evolution of the order parameter and of the electrochemical potential in this circuit; they converge to a stationary regime, and the voltage between the electrodes depends on the enclosed flux. We obtain expressions for the power dissipation and for the heat transported by the electric current; the validity of these expressions does not rely on a particular evolution model for the order parameter. We evaluate the influence of fluctuations. For a SQUID perimeter of the order of 1μ m and temperature 0.9T_c, we obtain a flux resolution of the order of 10^{-5}Φ _0/Hz^{1/2}; the resolution is expected to improve as the temperature is lowered.

Effects of Storage Temperature on the Quality of Frozen Squid

NASA Astrophysics Data System (ADS)

Kozima, Tsuneo; Ohtaka, Tateo

Squid ( Todarodes pacificus) , which is one of the main Japanzse coastal fish , was frozen under commercial condition after catch immediately and stored at -18 , -23 , -30 °C and 40 °C for 12 months. During storage the quality was measured by determining amount of free drip , water-holding capacity of muscle , weight ratio of cooking loss , histoligical feature of frozen and thawed muscle , and organoleptic test at regular intervals , each 2 months. Storage life of frozen squid was 12 months at below -18 °C.

SQUID-based microwave cavity search for dark-matter axions.

PubMed

Asztalos, S J; Carosi, G; Hagmann, C; Kinion, D; van Bibber, K; Hotz, M; Rosenberg, L J; Rybka, G; Hoskins, J; Hwang, J; Sikivie, P; Tanner, D B; Bradley, R; Clarke, J

2010-01-29

Axions in the microeV mass range are a plausible cold dark-matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. We report the first result from such an axion search using a superconducting first-stage amplifier (SQUID) replacing a conventional GaAs field-effect transistor amplifier. This experiment excludes KSVZ dark-matter axions with masses between 3.3 microeV and 3.53 microeV and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.

Degree-of-Freedom Strengthened Cascade Array for DOD-DOA Estimation in MIMO Array Systems.

PubMed

Yao, Bobin; Dong, Zhi; Zhang, Weile; Wang, Wei; Wu, Qisheng

2018-05-14

In spatial spectrum estimation, difference co-array can provide extra degrees-of-freedom (DOFs) for promoting parameter identifiability and parameter estimation accuracy. For the sake of acquiring as more DOFs as possible with a given number of physical sensors, we herein design a novel sensor array geometry named cascade array. This structure is generated by systematically connecting a uniform linear array (ULA) and a non-uniform linear array, and can provide more DOFs than some exist array structures but less than the upper-bound indicated by minimum redundant array (MRA). We further apply this cascade array into multiple input multiple output (MIMO) array systems, and propose a novel joint direction of departure (DOD) and direction of arrival (DOA) estimation algorithm, which is based on a reduced-dimensional weighted subspace fitting technique. The algorithm is angle auto-paired and computationally efficient. Theoretical analysis and numerical simulations prove the advantages and effectiveness of the proposed array structure and the related algorithm.

Very high frequency (beyond 100 MHz) PZT kerfless linear arrays.

PubMed

Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K Kirk

2009-10-01

This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-microm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-microm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss).

Very High Frequency (Beyond 100 MHz) PZT Kerfless Linear Arrays

PubMed Central

Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K. Kirk

2010-01-01

This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-µm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-µm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss). PMID:19942516

Sparse array angle estimation using reduced-dimension ESPRIT-MUSIC in MIMO radar.

PubMed

Zhang, Chaozhu; Pang, Yucai

2013-01-01

Sparse linear arrays provide better performance than the filled linear arrays in terms of angle estimation and resolution with reduced size and low cost. However, they are subject to manifold ambiguity. In this paper, both the transmit array and receive array are sparse linear arrays in the bistatic MIMO radar. Firstly, we present an ESPRIT-MUSIC method in which ESPRIT algorithm is used to obtain ambiguous angle estimates. The disambiguation algorithm uses MUSIC-based procedure to identify the true direction cosine estimate from a set of ambiguous candidate estimates. The paired transmit angle and receive angle can be estimated and the manifold ambiguity can be solved. However, the proposed algorithm has high computational complexity due to the requirement of two-dimension search. Further, the Reduced-Dimension ESPRIT-MUSIC (RD-ESPRIT-MUSIC) is proposed to reduce the complexity of the algorithm. And the RD-ESPRIT-MUSIC only demands one-dimension search. Simulation results demonstrate the effectiveness of the method.

Extraction and Propagation of an Intense Rotating Electron Beam,

DTIC Science & Technology

1982-10-01

radiochromic foils positioned at z = 25 cm. The equal transmission density contours are ranked in linear order of increasing exposure (increasing current...flux encircled by the cathode e = %rc2Bc. Linearizing the equation of motion around the equilibrium, we can find the wavelength of small radial...the beam rotation. The mask which precedes the scint- illator is a linear array of dots while the projection is made up of two disjoint linear arrays

Operational Prediction of the Habitat Suitability Index (HSI) Distribution for Neon Flying Squid in Central North Pacific by Using FORA Dataset and a New Data Assimilation System SKUIDS

NASA Astrophysics Data System (ADS)

Igarashi, H.; Ishikawa, Y.; Wakamatsu, T.; Tanaka, Y.; Nishikawa, S.; Nishikawa, H.; Kamachi, M.; Kuragano, T.; Takatsuki, Y.; Fujii, Y.; Usui, N.; Toyoda, T.; Hirose, N.; Sakai, M.; Saitoh, S. I.; Imamura, Y.

2016-02-01

The neon flying squid (Ommastrephes bartramii) has a wide-spread distribution in subtropical and temperate waters in the North Pacific, which plays an important role in the pelagic ecosystem and is one of the major targets in Japanese squid fisheries. The main fishing areas for Japanese commercial vessels are located in the central North Pacific (35-45N, around the date line) in summer. In this study, we have developed several kinds of habitat suitability index (HSI) models of the neon flying squid for investigating the relationship between its potential habitat and the ocean state variations in the target area. For developing HSI models, we have used a new ocean reanalysis dataset FORA (4-dimensional variational Ocean Re-Analysis) produced by JAMSTEC/CEIST and MRI-JMA. The horizontal resolution is 0.1*0.1 degree of latitude and longitude with 54 vertical levels, which can provide realistic fields of 3-dimensional ocean circulation and environmental structures including meso-scale eddies. In addition, we have developed a new 4D-VAR (4-dimensional variational) ocean data assimilation system for predicting ocean environmental changes in the main fishing grounds. We call this system "SKUIDS" (Scalable Kit of Under-sea Information Delivery System). By using these prediction fields of temperature, salinity, sea surface height, horizontal current velocity, we produced daily HSI maps of the neon flying squid, and provided them to the Japanese commercial vessels in operation. Squid fishermen can access the web site for delivering the information of ocean environments in the fishing ground by using Inmarsat satellite communication on board, and show the predicted fields of subsurface temperatures and HSI. Here, we present the details of SKUIDS and the web-delivery system for squid fishery, and some preliminary results of the operational prediction.

Fishing ground distribution of neon flying squid ( Ommastrephes bartramii) in relation to oceanographic conditions in the Northwest Pacific Ocean

NASA Astrophysics Data System (ADS)

Yu, Wei; Chen, Xinjun; Yi, Qian

2017-12-01

Neon flying squid, Ommastrephes bartramii, is a squid species of the North Pacific Ocean, which plays an important economical role in the international fishery. Logbook data for Chinese squid-jigging fishery over 2004-2011 were used to evaluate the relationship between the fishing grounds of the squid and the convergent frontal areas, which were defined by the contour lines of specific sea surface temperature (SST) and chlorophyll- a (Chl- a) concentration. Our results indicate that the SST in the range of 15 to 19°C and the Chl- a concentration in the range of 0.1 to 0.4 mg m-3 are the favorable conditions for the aggregation of the squid. Additionally, we deduced that the SST at 17.5°C and the Chl- a concentration at 0.25 mg m-3 are the optimal environmental conditions for the aggregation of O. bartramii. In August, the annual CPUE is positively correlated with the proportion of the fishing grounds with favorable SST and Chl- a concentration, as well as the combination of the two variables, implying that the abundance of the squid annually is largely depending on the presence of the favorable environmental conditions for fishery in August. Minor spatial difference between mean latitudinal location of the 17.5°C SST and 0.25 mg m-3 Chl- a fronts can increase the CPUEs of O. bartramii. Furthermore, the monthly latitudinal gravity centers of the CPUE closely followed the mean latitudinal position of the contour lines of the 17.5°C SST and the 0.25 mg m-3 Chl- a concentration. Our findings suggest the convergent oceanographic features (fronts) play significant roles in regulating the distribution and abundance of the western stock of the winter-spring cohort of O. bartramii, which can help people to improve their ability to discover the O. bartramii fishing grounds with higher productivity.

Impact localization on composite structures using time difference and MUSIC approach

NASA Astrophysics Data System (ADS)

Zhong, Yongteng; Xiang, Jiawei

2017-05-01

1-D uniform linear array (ULA) has the shortcoming of the half-plane mirror effect, which does not allow discriminating between a target placed above the array and a target placed below the array. This paper presents time difference (TD) and multiple signal classification (MUSIC) based omni-directional impact localization on a large stiffened composite structure using improved linear array, which is able to perform omni-directional 360° localization. This array contains 2M+3 PZT sensors, where 2M+1 PZT sensors are arranged as a uniform linear array, and the other two PZT sensors are placed above and below the array. Firstly, the arrival times of impact signals observed by the other two sensors are determined using the wavelet transform. Compared with each other, the direction range of impact source can be decided in general, 0°to 180° or 180°to 360°. And then, two dimensional multiple signal classification (2D-MUSIC) based spatial spectrum formula using the uniform linear array is applied for impact localization by the general direction range. When the arrival times of impact signals observed by upper PZT is equal to that of lower PZT, the direction can be located in x axis (0°or 180°). And time difference based MUSIC method is present to locate impact position. To verify the proposed approach, the proposed approach is applied to a composite structure. The localization results are in good agreement with the actual impact occurring positions.

Infrared-Bolometer Arrays with Reflective Backshorts

NASA Technical Reports Server (NTRS)

Miller, Timothy M.; Abrahams, John; Allen, Christine A.

2011-01-01

Integrated circuits that incorporate square arrays of superconducting-transition- edge bolometers with optically reflective backshorts are being developed for use in image sensors in the spectral range from far infrared to millimeter wavelengths. To maximize the optical efficiency (and, thus, sensitivity) of such a sensor at a specific wavelength, resonant optical structures are created by placing the backshorts at a quarter wavelength behind the bolometer plane. The bolometer and backshort arrays are fabricated separately, then integrated to form a single unit denoted a backshort-under-grid (BUG) bolometer array. In a subsequent fabrication step, the BUG bolometer array is connected, by use of single-sided indium bump bonding, to a readout device that comprises mostly a superconducting quantum interference device (SQUID) multiplexer circuit. The resulting sensor unit comprising the BUG bolometer array and the readout device is operated at a temperature below 1 K. The concept of increasing optical efficiency by use of backshorts at a quarter wavelength behind the bolometers is not new. Instead, the novelty of the present development lies mainly in several features of the design of the BUG bolometer array and the fabrication sequence used to implement the design. Prior to joining with the backshort array, the bolometer array comprises, more specifically, a square grid of free-standing molybdenum/gold superconducting-transition-edge bolometer elements on a 1.4- m-thick top layer of silicon that is part of a silicon support frame made from a silicon-on-insulator wafer. The backshort array is fabricated separately as a frame structure that includes support beams and contains a correspond - ing grid of optically reflective patches on a single-crystal silicon substrate. The process used to fabricate the bolometer array includes standard patterning and etching steps that result in the formation of deep notches in the silicon support frame. These notches are designed to interlock with the support beams on the backshort-array structure to provide structural support and precise relative positioning. The backshort-array structure is inserted in the silicon support frame behind the bolometer array, and the notches in the frame serve to receive the support beams of the backshort-array structure and thus determine the distance between the backshort and bolometer planes. The depth of the notches and, thus, the distance between the backshort and bolometer planes, can be tailored to a value between 25 to 300 m adjusting only a few process steps. The backshort array is designed so as not to interfere with the placement of indium bumps for subsequent indium bump-bonding to the multiplexing readout circuitry

Trace element content and magnetic properties of commercial HOPG samples studied by ion beam microscopy and SQUID magnetometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spemann, D., E-mail: spemann@uni-leipzig.de; Esquinazi, P., E-mail: esquin@physik.uni-leipzig.de; Setzer, A.

In this study, the impurity concentration and magnetic response of nine highly oriented pyrolytic graphite (HOPG) samples with different grades and from different providers were determined using ion beam microscopy and SQUID magnetometry. Apart from sideface contaminations in the as-received state, bulk contamination of the samples in most cases consists of disk-shaped micron-sized particles made of Ti and V with an additional Fe contamination around the grain perimeter. The saturation magnetization typically increases with Fe concentration, however, there is no simple correlation between Fe content and magnetic moment. The saturation magnetization of one, respectively six, out of nine samples clearlymore » exceeds the maximum contribution from pure Fe or Fe{sub 3}C. For most samples the temperature dependence of the remanence decreases linearly with T – a dependence found previously for defect-induced magnetism (DIM) in HOPG. We conclude that apart from magnetic impurities, additional contribution to the ferromagnetic magnetization exists in pristine HOPG in agreement with previous studies. A comparative study between the results of ion beam microscopy and the commonly used EDX analysis shows clearly that EDX is not a reliable method for quantitative trace elemental analysis in graphite, clarifying weaknesses and discrepancies in the element concentrations given in the recent literature.« less

TEM measurement in a low resistivity overburden performed by using low temperature SQUID

NASA Astrophysics Data System (ADS)

Ji, Yanju; Du, Shangyu; Xie, Lijun; Chang, Kai; Liu, Yang; Zhang, Yi; Xie, Xiaoming; Wang, Yuan; Lin, Jun; Rong, Liangliang

2016-12-01

Exploration of areas with thick low resistivity overburden is still a challenge for time domain transient electromagnetic method (TEM). We report modeling of a sandwich-layered earth by simulating the B field response with different conductive target layer thicknesses, thus obtaining a relationship between the resolution of the B field and the exploration depth. A low temperature Superconducting Quantum Interference Device (SQUID) is an ideal sensor for measuring the secondary magnetic field B in TEM measurements, because its sensitivity of several fT/√Hz is independent of frequency. In our TEM experiments, we utilized two different coils as receivers, a simple SQUID system, and a large transmitter loop of 200 × 200 m2 to compare the detected decay curves. At some measurement points, a decay signal of more than 300 ms duration was obtained by using the SQUID. Apparent resistivity profiles of about 9 km length are presented.

Intermodulation in nonlinear SQUID metamaterials: Experiment and theory

NASA Astrophysics Data System (ADS)

Zhang, Daimeng; Trepanier, Melissa; Antonsen, Thomas; Ott, Edward; Anlage, Steven M.

2016-11-01

The response of nonlinear metamaterials and superconducting electronics to two-tone excitation is critical for understanding their use as low-noise amplifiers and tunable filters. A new setting for such studies is that of metamaterials made of radio frequency superconducting quantum interference devices (rf-SQUIDs). The two-tone response of self-resonant rf-SQUID meta-atoms and metamaterials is studied here via intermodulation (IM) measurement over a broad range of tone frequencies and tone powers. A sharp onset followed by a surprising strongly suppressed IM region near the resonance is observed. Using a two time scale analysis technique, we present an analytical theory that successfully explains our experimental observations. The theory predicts that the IM can be manipulated with tone power, center frequency, frequency difference between the two tones, and temperature. This quantitative understanding potentially allows for the design of rf-SQUID metamaterials with either very low or very high IM response.

SQUID amplifiers for axion search experiments

NASA Astrophysics Data System (ADS)

Matlashov, Andrei; Schmelz, Matthias; Zakosarenko, Vyacheslav; Stolz, Ronny; Semertzidis, Yannis K.

2018-04-01

In the experiments for dark-matter QCD-axion searches, very weak microwave signals from a low-temperature High-Q resonant cavity should be detected using the highest sensitivity. The best commercial low-noise cryogenic semiconductor amplifiers based on high electron mobility transistors have a lowest noise temperature above 1.0 K, even if they are cooled well below 1 K. Superconducting quantum interference devices can work as microwave amplifiers with temperature noise close to the standard quantum limit. Previous SQUID-based RF amplifiers designed for axion search experiments have a microstrip resonant input coil and are thus called micro-strip SQUID amplifiers or MSAs. Due to the resonant input coupling they usually have narrow bandwidth. In this paper we report on a SQUID-based wideband microwave amplifier fabricated using sub-micron size Josephson junctions with very low capacitance. A single amplifier can be used in a frequency range of approximately 1-5 GHz.

Tracking Electromagnetic Energy With SQUIDs

NASA Technical Reports Server (NTRS)

2005-01-01

A superconducting quantum interference device (SQUID) is a gadget used to measure extremely weak signals, specifically magnetic flux. It can detect subtle changes in energy, up to 100 billion times weaker than the electromagnetic energy required to move a compass needle. SQUIDs are used for a variety of testing procedures where extreme sensitivity is required and where the test instrument need not come into direct contact with the test subject. NASA uses SQUIDs for remote, noncontact sensing in a variety of venues, including monitoring the Earth s magnetic field and tracking brain activity of pilots. Scientists at NASA s Goddard Space Flight Center have been making extensive use of this technology, from astrophysical research, to tracking the navigational paths of bees in flight to determine if they are using internal compasses. These very sensitive measurement devices have a wide variety of uses within NASA and even more uses within the commercial realm.

Study on nondestructive inspection using HTS-SQUID for friction stir welding between dissimilar metals

NASA Astrophysics Data System (ADS)

Hatsukade, Y.; Takahashi, T.; Yasui, T.; Tsubaki, M.; Fukumono, M.; Tanaka, S.

2007-10-01

We have developed an SQUID-NDI technique for evaluation of friction stir welding (FSW) between aluminum alloy A6063 and stainless steel SUS304 from the electric conductivities in board specimens bonded by FSW. A SQUID-NDI system employing an HTS-SQUID gradiometer was constructed to measure current distribution in the FSW specimens by applying voltage to the specimen. By measuring field gradients dBz/dy and dBz/dx above the FSW specimens made with various FSW conditions and then converting them to current vector Jx and Jy, conductivities of FSW areas were estimated. Due to the difference in the FSW conditions, the conductivity distributions varied dramatically. From these results, it was suggested that the conductivities in FSW areas should be varied due to the temperature heated by the friction between the milling tool and the materials.

Application of SQUIDs for registration of biomagnetic signals

NASA Astrophysics Data System (ADS)

Voitovych, I. D.; Primin, M. A.; Sosnytskyy, V. N.

2012-04-01

Supersensitive magnetometric systems based on low-temperature SQUIDs have been designed to conduct research in cardiology (magnetocardiography) and to examine distribution of magnetic nanoparticles in biologic objects. Such SQUID magnetometric systems are distinguished by their noise immunity enabling research in nonscreened rooms. High repeatability of research outcomes has been confirmed. The use of magnetocardiographic systems has permitted a new screening information technology to be developed to diagnose heart diseases at early stages. Magnetic imaging of heart's action currents is an ideal way to test local electrical heterogeneity of myocardium. It is shown that magnetocardiography has a significant potential for both basic science of analysis of heart's biosignals and clinical cardiologic practice. A SQUID magnetometric system measuring magnetic signals radiated by the organs of laboratory animals is described. Information technology for automatic recording and transforming magnetometric data has been developed; the measurement of signals over rats' livers while injecting intravenously the nanoparticles of iron oxides and lead solutions are presented.

Microfluidic systems for investigating host-microbe relationship

NASA Astrophysics Data System (ADS)

Bhattacharjee, Arunima; Vincent, Lionel; Nawroth, Janna; Ruby, Ned; McFall-Ngai, Margaret; Kanso, Eva; Biodynamics Laboratory Collaboration; Pacific Biosciences Research Center Collaboration

2017-11-01

The symbiosis between the bioluminescent bacterium, Vibrio fisheri, and the Hawaiian bobtail squid, Euprymna scolopes, has been widely studied, and this association is used as a model system for studying bacterial colonization of ciliated host tissues. The recruitment of Vibrio fisheri to a specialized light organ in the nascent squid is facilitated by various chemosensing and mechanosensing events. To decipher the effects of such environmental and host-derived sensors on bacterial physiology, we use specifically designed microfluidic channels to engineer chemical and mechanical fields similar to those observed in the light organ of the squid. These in vitrostudies are aimed at complementing ongoing in vivo studies in the system squid-vibrio system. This approach enables us, for the first time, to isolate the effect of mechanical and chemical cues on bacterial motility in this symbiosis and to quantify the bacterial response to these cues. NSF Inspire.

Source localization of brain activity using helium-free interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dammers, Jürgen, E-mail: J.Dammers@fz-juelich.de; Chocholacs, Harald; Eich, Eberhard

2014-05-26

To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localizationmore » of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.« less

The jumbo squid, Dosidicus gigas (Ommastrephidae), living in oxygen minimum zones II: Blood-oxygen binding

NASA Astrophysics Data System (ADS)

Seibel, Brad A.

2013-10-01

Dosidicus gigas is a large, metabolically active squid that migrates across a strong oxygen and temperature gradient in the Eastern Pacific. Here we analyze the oxygen-binding properties of the squid's respiratory protein (hemocyanin, Hc) that facilitate such activity. A high Hc-oxygen affinity, strong temperature dependence, and pronounced pH sensitivity (P50=0.009T2.03, pH 7.4; Bohr coefficient=ΔlogP50/ΔpH=-1.55+0.034T) of oxygen binding facilitate night-time foraging in the upper water column, and support suppressed oxygen demand in hypoxic waters at greater depths. Expanding hypoxia may act to alter the species habitable depth range. This analysis supports the contention that ocean acidification could limit oxygen carrying capacity in squids at warmer temperature leading to reduced activity levels or altered distribution.

Optical transmission modules for multi-channel superconducting quantum interference device readouts.

PubMed

Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong

2013-12-01

We developed an optical transmission module consisting of 16-channel analog-to-digital converter (ADC), digital-noise filter, and one-line serial transmitter, which transferred Superconducting Quantum Interference Device (SQUID) readout data to a computer by a single optical cable. A 16-channel ADC sent out SQUID readouts data with 32-bit serial data of 8-bit channel and 24-bit voltage data at a sample rate of 1.5 kSample/s. A digital-noise filter suppressed digital noises generated by digital clocks to obtain SQUID modulation as large as possible. One-line serial transmitter reformed 32-bit serial data to the modulated data that contained data and clock, and sent them through a single optical cable. When the optical transmission modules were applied to 152-channel SQUID magnetoencephalography system, this system maintained a field noise level of 3 fT/√Hz @ 100 Hz.

Linear CCD attitude measurement system based on the identification of the auxiliary array CCD

NASA Astrophysics Data System (ADS)

Hu, Yinghui; Yuan, Feng; Li, Kai; Wang, Yan

2015-10-01

Object to the high precision flying target attitude measurement issues of a large space and large field of view, comparing existing measurement methods, the idea is proposed of using two array CCD to assist in identifying the three linear CCD with multi-cooperative target attitude measurement system, and to address the existing nonlinear system errors and calibration parameters and more problems with nine linear CCD spectroscopic test system of too complicated constraints among camera position caused by excessive. The mathematical model of binocular vision and three linear CCD test system are established, co-spot composition triangle utilize three red LED position light, three points' coordinates are given in advance by Cooperate Measuring Machine, the red LED in the composition of the three sides of a triangle adds three blue LED light points as an auxiliary, so that array CCD is easier to identify three red LED light points, and linear CCD camera is installed of a red filter to filter out the blue LED light points while reducing stray light. Using array CCD to measure the spot, identifying and calculating the spatial coordinates solutions of red LED light points, while utilizing linear CCD to measure three red LED spot for solving linear CCD test system, which can be drawn from 27 solution. Measured with array CCD coordinates auxiliary linear CCD has achieved spot identification, and has solved the difficult problems of multi-objective linear CCD identification. Unique combination of linear CCD imaging features, linear CCD special cylindrical lens system is developed using telecentric optical design, the energy center of the spot position in the depth range of convergence in the direction is perpendicular to the optical axis of the small changes ensuring highprecision image quality, and the entire test system improves spatial object attitude measurement speed and precision.

Thermal-Independent Properties of PIN-PMN-PT Single-Crystal Linear-Array Ultrasonic Transducers

PubMed Central

Chen, Ruimin; Wu, Jinchuan; Lam, Kwok Ho; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K. Kirk

2013-01-01

In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 (PIN-PMN-PT) and binary Pb(Mg1/3Nb2/3)–PbTiO3 (PMN-PT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a −6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

Squid Giant Axon Contains Neurofilament Protein mRNA but does not Synthesize Neurofilament Proteins.

PubMed

Gainer, Harold; House, Shirley; Kim, Dong Sun; Chin, Hemin; Pant, Harish C

2017-04-01

When isolated squid giant axons are incubated in radioactive amino acids, abundant newly synthesized proteins are found in the axoplasm. These proteins are translated in the adaxonal Schwann cells and subsequently transferred into the giant axon. The question as to whether any de novo protein synthesis occurs in the giant axon itself is difficult to resolve because the small contribution of the proteins possibly synthesized intra-axonally is not easily distinguished from the large amounts of the proteins being supplied from the Schwann cells. In this paper, we reexamine this issue by studying the synthesis of endogenous neurofilament (NF) proteins in the axon. Our laboratory previously showed that NF mRNA and protein are present in the squid giant axon, but not in the surrounding adaxonal glia. Therefore, if the isolated squid axon could be shown to contain newly synthesized NF protein de novo, it could not arise from the adaxonal glia. The results of experiments in this paper show that abundant 3H-labeled NF protein is synthesized in the squid giant fiber lobe containing the giant axon's neuronal cell bodies, but despite the presence of NF mRNA in the giant axon no labeled NF protein is detected in the giant axon. This lends support to the glia-axon protein transfer hypothesis which posits that the squid giant axon obtains newly synthesized protein by Schwann cell transfer and not through intra-axonal protein synthesis, and further suggests that the NF mRNA in the axon is in a translationally repressed state.

Range expansion of the jumbo squid in the NE Pacific: δ15N decrypts multiple origins, migration and habitat use.

PubMed

Ruiz-Cooley, Rocio I; Ballance, Lisa T; McCarthy, Matthew D

2013-01-01

Coincident with climate shifts and anthropogenic perturbations, the highly voracious jumbo squid Dosidicus gigas reached unprecedented northern latitudes along the NE Pacific margin post 1997-98. The physical or biological drivers of this expansion, as well as its ecological consequences remain unknown. Here, novel analysis from both bulk tissues and individual amino acids (Phenylalanine; Phe and Glutamic acid; Glu) in both gladii and muscle of D. gigas captured in the Northern California Current System (NCCS) documents for the first time multiple geographic origins and migration. Phe δ(15)N values, a proxy for habitat baseline δ(15)N values, confirm at least three different geographic origins that were initially detected by highly variable bulk δ(15)N values in gladii for squid at small sizes (<30 cm gladii length). In contrast, bulk δ(15)N values from gladii of large squid (>60 cm) converged, indicating feeding in a common ecosystem. The strong latitudinal gradient in Phe δ(15)N values from composite muscle samples further confirmed residency at a point in time for large squid in the NCCS. These results contrast with previous ideas, and indicate that small squid are highly migratory, move into the NCCS from two or more distinct geographic origins, and use this ecosystem mainly for feeding. These results represent the first direct information on the origins, immigration and habitat use of this key "invasive" predator in the NCCS, with wide implications for understanding both the mechanisms of periodic D. gigas population range expansions, and effects on ecosystem trophic structure.

Range Expansion of the Jumbo Squid in the NE Pacific: δ15N Decrypts Multiple Origins, Migration and Habitat Use

PubMed Central

Ruiz-Cooley, Rocio I.; Ballance, Lisa T.; McCarthy, Matthew D.

2013-01-01

Coincident with climate shifts and anthropogenic perturbations, the highly voracious jumbo squid Dosidicus gigas reached unprecedented northern latitudes along the NE Pacific margin post 1997–98. The physical or biological drivers of this expansion, as well as its ecological consequences remain unknown. Here, novel analysis from both bulk tissues and individual amino acids (Phenylalanine; Phe and Glutamic acid; Glu) in both gladii and muscle of D. gigas captured in the Northern California Current System (NCCS) documents for the first time multiple geographic origins and migration. Phe δ15N values, a proxy for habitat baseline δ15N values, confirm at least three different geographic origins that were initially detected by highly variable bulk δ15N values in gladii for squid at small sizes (<30 cm gladii length). In contrast, bulk δ15N values from gladii of large squid (>60 cm) converged, indicating feeding in a common ecosystem. The strong latitudinal gradient in Phe δ15N values from composite muscle samples further confirmed residency at a point in time for large squid in the NCCS. These results contrast with previous ideas, and indicate that small squid are highly migratory, move into the NCCS from two or more distinct geographic origins, and use this ecosystem mainly for feeding. These results represent the first direct information on the origins, immigration and habitat use of this key “invasive” predator in the NCCS, with wide implications for understanding both the mechanisms of periodic D. gigas population range expansions, and effects on ecosystem trophic structure. PMID:23527242

O-antigen and Core Carbohydrate of Vibrio fischeri Lipopolysaccharide

PubMed Central

Post, Deborah M. B.; Yu, Liping; Krasity, Benjamin C.; Choudhury, Biswa; Mandel, Mark J.; Brennan, Caitlin A.; Ruby, Edward G.; McFall-Ngai, Margaret J.; Gibson, Bradford W.; Apicella, Michael A.

2012-01-01

Vibrio fischeri exists in a symbiotic relationship with the Hawaiian bobtail squid, Euprymna scolopes, where the squid provides a home for the bacteria, and the bacteria in turn provide camouflage that helps protect the squid from night-time predators. Like other Gram-negative organisms, V. fischeri expresses lipopolysaccharide (LPS) on its cell surface. The structure of the O-antigen and the core components of the LPS and their possible role in colonization of the squid have not previously been determined. In these studies, an O-antigen ligase mutant, waaL, was utilized to determine the structures of these LPS components and their roles in colonization of the squid. WaaL ligates the O-antigen to the core of the LPS; thus, LPS from waaL mutants lacks O-antigen. Our results show that the V. fischeri waaL mutant has a motility defect, is significantly delayed in colonization, and is unable to compete with the wild-type strain in co-colonization assays. Comparative analyses of the LPS from the wild-type and waaL strains showed that the V. fischeri LPS has a single O-antigen repeat composed of yersiniose, 8-epi-legionaminic acid, and N-acetylfucosamine. In addition, the LPS from the waaL strain showed that the core structure consists of l-glycero-d-manno-heptose, d-glycero-d-manno-heptose, glucose, 3-deoxy-d-manno-octulosonic acid, N-acetylgalactosamine, 8-epi-legionaminic acid, phosphate, and phosphoethanolamine. These studies indicate that the unusual V. fischeri O-antigen sugars play a role in the early phases of bacterial colonization of the squid. PMID:22247546

Long linear MWIR and LWIR HgCdTe infrared detection arrays for high resolution imaging

NASA Astrophysics Data System (ADS)

Chamonal, Jean-Paul; Audebert, Patrick; Medina, Philippe; Destefanis, Gérard; Deschamps, Joel R.; Girard, Michel; Chatard, Jean-Pierre

2018-04-01

This paper, "Long linear MWIR and LWIR HgCdTe infrared detection arrays for high resolution imaging," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

New fabrication of high-frequency (100-MHz) ultrasound PZT film kerfless linear array.

PubMed

Zhu, Benpeng; Chan, Ngai Yui; Dai, Jiyan; Shung, K Kirk; Takeuchi, Shinichi; Zhou, Qifa

2013-04-01

The paper describes the design, fabrication, and measurements of a high-frequency ultrasound kerfless linear array prepared from hydrothermal lead zirconate titanate (PZT) thick film. The 15-μm hydrothermal PZT thick film with an area of 1 × 1 cm, obtained through a self-separation process from Ti substrate, was used to fabricate a 32-element 100-MHz kerfless linear array with photolithography. The bandwidth at -6 dB without matching layer, insertion loss around center frequency, and crosstalk between adjacent elements were measured to be 39%, -30 dB, and -15 dB, respectively.

Linear-array based full-view high-resolution photoacoustic computed tomography of whole mouse brain functions in vivo

NASA Astrophysics Data System (ADS)

Li, Lei; Zhang, Pengfei; Wang, Lihong V.

2018-02-01

Photoacoustic computed tomography (PACT) is a non-invasive imaging technique offering high contrast, high resolution, and deep penetration in biological tissues. We report a photoacoustic computed tomography (PACT) system equipped with a high frequency linear array for anatomical and functional imaging of the mouse whole brain. The linear array was rotationally scanned in the coronal plane to achieve the full-view coverage. We investigated spontaneous neural activities in the deep brain by monitoring the hemodynamics and observed strong interhemispherical correlations between contralateral regions, both in the cortical layer and in the deep regions.

Preliminary Assessment of Microwave Readout Multiplexing Factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croce, Mark Philip; Koehler, Katrina Elizabeth; Rabin, Michael W.

2017-01-23

Ultra-high resolution microcalorimeter gamma spectroscopy is a new non-destructive assay technology for measurement of plutonium isotopic composition, with the potential to reduce total measurement uncertainty to a level competitive with destructive analysis methods [1-4]. Achieving this level of performance in practical applications requires not only the energy resolution now routinely achieved with transition-edge sensor microcalorimeter arrays (an order of magnitude better than for germanium detectors) but also high throughput. Microcalorimeter gamma spectrometers have not yet achieved detection efficiency and count rate capability that is comparable to germanium detectors, largely because of limits from existing readout technology. Microcalorimeter detectors must bemore » operated at low temperature to achieve their exceptional energy resolution. Although the typical 100 mK operating temperatures can be achieved with reliable, cryogen-free systems, the cryogenic complexity and heat load from individual readout channels for large sensor arrays is prohibitive. Multiplexing is required for practical systems. The most mature multiplexing technology at present is time-division multiplexing (TDM) [3, 5-6]. In TDM, the sensor outputs are switched by applying bias current to one SQUID amplifier at a time. Transition-edge sensor (TES) microcalorimeter arrays as large as 256 pixels have been developed for X-ray and gamma-ray spectroscopy using TDM technology. Due to bandwidth limits and noise scaling, TDM is limited to a maximum multiplexing factor of approximately 32-40 sensors on one readout line [8]. Increasing the size of microcalorimeter arrays above the kilopixel scale, required to match the throughput of germanium detectors, requires the development of a new readout technology with a much higher multiplexing factor.« less

Thermopile Detector Arrays for Space Science Applications

NASA Technical Reports Server (NTRS)

Foote, M. C.; Kenyon, M.; Krueger, T. R.; McCann, T. A.; Chacon, R.; Jones, E. W.; Dickie, M. R.; Schofield, J. T.; McCleese, D. J.; Gaalema, S.

2004-01-01

Thermopile detectors are widely used in uncooled applications where small numbers of detectors are required, particularly in low-cost commercial applications or applications requiring accurate radiometry. Arrays of thermopile detectors, however, have not been developed to the extent of uncooled bolometer and pyroelectric/ferroelectric arrays. Efforts at JPL seek to remedy this deficiency by developing high performance thin-film thermopile detectors in both linear and two-dimensional formats. The linear thermopile arrays are produced by bulk micromachining and wire bonded to separate CMOS readout electronic chips. Such arrays are currently being fabricated for the Mars Climate Sounder instrument, scheduled for launch in 2005. Progress is also described towards realizing a two-dimensional thermopile array built over CMOS readout circuitry in the substrate.

Environmentally driven synchronies of Mediterranean cephalopod populations

NASA Astrophysics Data System (ADS)

Keller, Stefanie; Quetglas, Antoni; Puerta, Patricia; Bitetto, Isabella; Casciaro, Loredana; Cuccu, Danila; Esteban, Antonio; Garcia, Cristina; Garofalo, Germana; Guijarro, Beatriz; Josephides, Marios; Jadaud, Angelique; Lefkaditou, Evgenia; Maiorano, Porzia; Manfredi, Chiara; Marceta, Bojan; Micallef, Reno; Peristeraki, Panagiota; Relini, Giulio; Sartor, Paolo; Spedicato, Maria Teresa; Tserpes, George; Hidalgo, Manuel

2017-03-01

The Mediterranean Sea is characterized by large scale gradients of temperature, productivity and salinity, in addition to pronounced mesoscale differences. Such a heterogeneous system is expected to shape the population dynamics of marine species. On the other hand, prevailing environmental and climatic conditions at whole basin scale may force spatially distant populations to fluctuate in synchrony. Cephalopods are excellent case studies to test these hypotheses owing to their high sensitivity to environmental conditions. Data of two cephalopod species with contrasting life histories (benthic octopus vs nectobenthic squid), obtained from scientific surveys carried out throughout the Mediterranean during the last 20 years were analyzed. The objectives of this study and the methods used to achieve them (in parentheses) were: (i) to investigate synchronies in spatially separated populations (decorrelation analysis); (ii) detect underlying common abundance trends over distant regions (dynamic factor analysis, DFA); and (iii) analyse putative influences of key environmental drivers such as productivity and sea surface temperature on the population dynamics at regional scale (general linear models, GLM). In accordance with their contrasting spatial mobility, the distance from where synchrony could no longer be detected (decorrelation scale) was higher in squid than in octopus (349 vs 217 km); for comparison, the maximum distance between locations was 2620 km. The DFA revealed a general increasing trend in the abundance of both species in most areas, which agrees with the already reported worldwide proliferation of cephalopods. DFA results also showed that population dynamics are more similar in the eastern than in the western Mediterranean basin. According to the GLM models, cephalopod populations were negatively affected by productivity, which would be explained by an increase of competition and predation by fishes. While warmer years coincided with declining octopus numbers, areas of high sea surface temperature showed higher densities of squid. Our results are relevant for regional fisheries management and demonstrate that the regionalisation objectives envisaged under the new Common Fishery Policy may not be adequate for Mediterranean cephalopod stocks.

MTF measurement and analysis of linear array HgCdTe infrared detectors

NASA Astrophysics Data System (ADS)

Zhang, Tong; Lin, Chun; Chen, Honglei; Sun, Changhong; Lin, Jiamu; Wang, Xi

2018-01-01

The slanted-edge technique is the main method for measurement detectors MTF, however this method is commonly used on planar array detectors. In this paper the authors present a modified slanted-edge method to measure the MTF of linear array HgCdTe detectors. Crosstalk is one of the major factors that degrade the MTF value of such an infrared detector. This paper presents an ion implantation guard-ring structure which was designed to effectively absorb photo-carriers that may laterally defuse between adjacent pixels thereby suppressing crosstalk. Measurement and analysis of the MTF of the linear array detectors with and without a guard-ring were carried out. The experimental results indicated that the ion implantation guard-ring structure effectively suppresses crosstalk and increases MTF value.

Sensitive spin detection using an on-chip SQUID-waveguide resonator

NASA Astrophysics Data System (ADS)

Yue, G.; Chen, L.; Barreda, J.; Bevara, V.; Hu, L.; Wu, L.; Wang, Z.; Andrei, P.; Bertaina, S.; Chiorescu, I.

2017-11-01

Precise detection of spin resonance is of paramount importance to achieve coherent spin control in quantum computing. We present a setup for spin resonance measurements, which uses a dc-SQUID flux detector coupled to an antenna from a coplanar waveguide. The SQUID and the waveguide are fabricated from a 20 nm Nb thin film, allowing high magnetic field operation with the field applied parallel to the chip. We observe a resonance signal between the first and third excited states of Gd spins S = 7/2 in a CaWO4 crystal, relevant for state control in multi-level systems.

50 CFR Table 3 to Part 679 - Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut

Code of Federal Regulations, 2013 CFR

2013-10-01

... 0.50 870 Octopus 1.00 0.98 0.81 875 Squid 1.00 0.98 0.69 Rockfish 1.00 0.98 0.88 0.60 0.50 200... Capelin Sharks 0.30 0.30 0.25 Skates 710 Sablefish 0.05 0.35 0.30 0.30 0.25 870 Octopus 875 Squid Rockfish... Sablefish 0.17 0.00 1.00 870 Octopus 0.17 0.85 0.00 1.00 875 Squid 0.17 0.75 0.00 1.00 Rockfish 0.00 1.00...

50 CFR Table 3 to Part 679 - Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut

Code of Federal Regulations, 2014 CFR

2014-10-01

... 0.50 870 Octopus 1.00 0.98 0.81 875 Squid 1.00 0.98 0.69 Rockfish 1.00 0.98 0.88 0.60 0.50 200... Capelin Sharks 0.30 0.30 0.25 Skates 710 Sablefish 0.05 0.35 0.30 0.30 0.25 870 Octopus 875 Squid Rockfish... Sablefish 0.17 0.00 1.00 870 Octopus 0.17 0.85 0.00 1.00 875 Squid 0.17 0.75 0.00 1.00 Rockfish 0.00 1.00...

Squid detected NMR and MRI at ultralow fields

DOEpatents

Clarke, John [Berkeley, CA; McDermott, Robert [Louisville, CO; Pines, Alexander [Berkeley, CA; Trabesinger, Andreas Heinz [CH-8006 Zurich, CH

2007-05-15

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Squid detected NMR and MRI at ultralow fields

DOEpatents

Clarke, John; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

2006-05-30

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Squid detected NMR and MRI at ultralow fields

DOEpatents

Clarke, John [Berkeley, CA; Pines, Alexander [Berkeley, CA; McDermott, Robert F [Monona, WI; Trabesinger, Andreas H [London, GB

2008-12-16

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

SQUID detected NMR and MRI at ultralow fields

DOEpatents

Clarke, John; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

2006-10-03

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Transport characteristics of μ-SQUIDs for probing magnetism

NASA Astrophysics Data System (ADS)

Biswas, Sourav; Paul, Sagar; Parashari, Harsh; Winkelmann, Clemens B.; Courtois, Hervé; Gupta, Anjan K.

2018-04-01

We study the transport properties of niobium (Nb) based micron sized superconducting quantum interference devices (μ-SQUID), which are designed to eliminate thermal hysteresis down to 1.3 K. Current-voltage characteristics are non-hysterestic at the lowest temperature. Large voltage oscillations with magnetic field are observed for a wide range of bias currents with good flux sensitivity and reduced flux noise. However, devices with fins and devices on sapphire substrate show hysteresis for wide range of bath temperature. We have also been able to see the sign of magnetic response from a single micron size ferromagnetic permalloy ellipse using the μ-SQUID.

Trophic relationships of albatrosses associated with squid and large-mesh drift-net fisheries in the North Pacific Ocean

USGS Publications Warehouse

Gould, Patrick J.; Ostrom, Peggy H.; Walker, William

1997-01-01

The diets of Laysan (Diomedea immutabilis) and black-footed albatrosses (D. nigripes) killed in squid and large-mesh drift nets in the transitional zone of the North Pacific Ocean were investigated by examining the contents of the digestive tracts and determining δ13C and δ15N values in breast-muscle tissue. The results show that (i) the combined prey of the two species of albatross consists of over 46 species of marine organisms including coelenterates, arthropods, mollusks, fish, and marine mammals; (ii) both species supplement their traditional diets with food made available by commercial fishing operations (e.g., net-caught squid and offal); (iii) while obtained from drift nets, diets of nonbreeding Laysan and black-footed albatrosses are dominated by neon flying squid (Ommastrephes bartrami); (iv) in the absence of drift-net-related food, Laysan albatrosses feed most heavily on fish and black-footed albatrosses feed most heavily on squid; and (v) based on δ15N values, nonbreeding adult Laysan albatrosses from the transitional zone of the North Pacific Ocean and Laysan albatross nestlings fed by adults from Midway Island in the subtropical Pacific feed at one trophic level and one-third of a trophic level lower than black-footed albatrosses, respectively.

Characterization and demonstration results of a SQUID magnetometer system developed for geomagnetic field measurements

NASA Astrophysics Data System (ADS)

Kawai, J.; Miyamoto, M.; Kawabata, M.; Nosé, M.; Haruta, Y.; Uehara, G.

2017-08-01

We characterized a low temperature superconducting quantum interference device (SQUID) magnetometer system developed for high-sensitivity geomagnetic field measurement, and demonstrated the detection of weak geomagnetic signals. The SQUID magnetometer system is comprised of three-axis SQUID magnetometers housed in a glass fiber reinforced plastic cryostat, readout electronics with flux locked loop (FLL), a 24-bit data logger with a global positioning system and batteries. The system noise was approximately 0.2 pT √Hz- 1/2 in the 1-50 Hz frequency range. This performance was determined by including the thermal noise and the shielding effect of the copper shield, which covered the SQUID magnetometers to eliminate high-frequency interference. The temperature drift of the system was ˜0.8 pT °C- 1 in an FLL operation. The system operated for a month using 33 l liquid helium. Using this system, we performed the measurements of geomagnetic field in the open-air, far away from the city. The system could detect weak geomagnetic signals such as the Schumann resonance with sixth harmonics, and the ionospheric Alfvén resonance appearing at night, for the north-south and east-west components of the geomagnetic field. We confirm that the system was capable of high-sensitivity measurement of the weak geomagnetic activities.

Extraction and characterization of collagen from Antarctic and Sub-Antarctic squid and its potential application in hybrid scaffolds for tissue engineering.

PubMed

Coelho, Rui C G; Marques, Ana L P; Oliveira, Sara M; Diogo, Gabriela S; Pirraco, Rogério P; Moreira-Silva, Joana; Xavier, José C; Reis, Rui L; Silva, Tiago H; Mano, João F

2017-09-01

Collagen is the most abundant protein found in mammals and it exhibits a low immunogenicity, high biocompatibility and biodegradability when compared with others natural polymers. For this reason, it has been explored for the development of biologically instructive biomaterials with applications for tissue substitution and regeneration. Marine origin collagen has been pursued as an alternative to the more common bovine and porcine origins. This study focused on squid (Teuthoidea: Cephalopoda), particularly the Antarctic squid Kondakovia longimana and the Sub-Antarctic squid Illex argentinus as potential collagen sources. In this study, collagen has been isolated from the skins of the squids using acid-based and pepsin-based protocols, with the higher yield being obtained from I. argentinus in the presence of pepsin. The produced collagen has been characterized in terms of physicochemical properties, evidencing an amino acid profile similar to the one of calf collagen, but exhibiting a less preserved structure, with hydrolyzed portions and a lower melting temperature. Pepsin-soluble collagen isolated from I. argentinus was selected for further evaluation of biomedical potential, exploring its incorporation on poly-ε-caprolactone (PCL) 3D printed scaffolds for the development of hybrid scaffolds for tissue engineering, exhibiting hierarchical features. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression of squid iridescence depends on environmental luminance and peripheral ganglion control.

PubMed

Gonzalez-Bellido, P T; Wardill, T J; Buresch, K C; Ulmer, K M; Hanlon, R T

2014-03-15

Squid display impressive changes in body coloration that are afforded by two types of dynamic skin elements: structural iridophores (which produce iridescence) and pigmented chromatophores. Both color elements are neurally controlled, but nothing is known about the iridescence circuit, or the environmental cues, that elicit iridescence expression. To tackle this knowledge gap, we performed denervation, electrical stimulation and behavioral experiments using the long-fin squid, Doryteuthis pealeii. We show that while the pigmentary and iridescence circuits originate in the brain, they are wired differently in the periphery: (1) the iridescence signals are routed through a peripheral center called the stellate ganglion and (2) the iridescence motor neurons likely originate within this ganglion (as revealed by nerve fluorescence dye fills). Cutting the inputs to the stellate ganglion that descend from the brain shifts highly reflective iridophores into a transparent state. Taken together, these findings suggest that although brain commands are necessary for expression of iridescence, integration with peripheral information in the stellate ganglion could modulate the final output. We also demonstrate that squid change their iridescence brightness in response to environmental luminance; such changes are robust but slow (minutes to hours). The squid's ability to alter its iridescence levels may improve camouflage under different lighting intensities.

Age, maturation, and population structure of the Humboldt squid Dosidicus gigas off the Peruvian Exclusive Economic Zones

NASA Astrophysics Data System (ADS)

Liu, Bilin; Chen, Xinjun; Chen, Yong; Tian, Siquan; Li, Jianhua; Fang, Zhou; Yang, Mingxia

2013-01-01

Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones (EEZ) during 2008-2010. Estimated ages ranged from 144 to 633 days, confirming that the squid is a short-lived species with longevity no longer than 2 years. Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round. Back-calculated hatching dates for the samples were from January 22nd, 2008 to April 22nd, 2010 with a peak between January and March. Two size-based and two hatching date-based populations could be defined from mantle length (ML) at maturity and back-calculated hatching dates, respectively. Females matured at a larger size than males, and there was a significant difference in ML at maturity between the two hatching groups ( P <0.05). The waters adjacent to 11°S off the Peruvian EEZ may be a potential spawning ground. This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ, which should be considered in the assessment and management of this important resource.

Loudness-dependent behavioral responses and habituation to sound by the longfin squid (Doryteuthis pealeii).

PubMed

Mooney, T Aran; Samson, Julia E; Schlunk, Andrea D; Zacarias, Samantha

2016-07-01

Sound is an abundant cue in the marine environment, yet we know little regarding the frequency range and levels which induce behavioral responses in ecologically key marine invertebrates. Here we address the range of sounds that elicit unconditioned behavioral responses in squid Doryteuthis pealeii, the types of responses generated, and how responses change over multiple sound exposures. A variety of response types were evoked, from inking and jetting to body pattern changes and fin movements. Squid responded to sounds from 80 to 1000 Hz, with response rates diminishing at the higher and lower ends of this frequency range. Animals responded to the lowest sound levels in the 200-400 Hz range. Inking, an escape response, was confined to the lower frequencies and highest sound levels; jetting was more widespread. Response latencies were variable but typically occurred after 0.36 s (mean) for jetting and 0.14 s for body pattern changes; pattern changes occurred significantly faster. These results demonstrate that squid can exhibit a range of behavioral responses to sound include fleeing, deimatic and protean behaviors, all of which are associated with predator evasion. Response types were frequency and sound level dependent, reflecting a relative loudness concept to sound perception in squid.

Tandem Repeat Proteins Inspired By Squid Ring Teeth

NASA Astrophysics Data System (ADS)

Pena-Francesch, Abdon

Proteins are large biomolecules consisting of long chains of amino acids that hierarchically assemble into complex structures, and provide a variety of building blocks for biological materials. The repetition of structural building blocks is a natural evolutionary strategy for increasing the complexity and stability of protein structures. However, the relationship between amino acid sequence, structure, and material properties of protein systems remains unclear due to the lack of control over the protein sequence and the intricacies of the assembly process. In order to investigate the repetition of protein building blocks, a recently discovered protein from squids is examined as an ideal protein system. Squid ring teeth are predatory appendages located inside the suction cups that provide a strong grasp of prey, and are solely composed of a group of proteins with tandem repetition of building blocks. The objective of this thesis is the understanding of sequence, structure and property relationship in repetitive protein materials inspired in squid ring teeth for the first time. Specifically, this work focuses on squid-inspired structural proteins with tandem repeat units in their sequence (i.e., repetition of alternating building blocks) that are physically cross-linked via beta-sheet structures. The research work presented here tests the hypothesis that, in these systems, increasing the number of building blocks in the polypeptide chain decreases the protein network defects and improves the material properties. Hence, the sequence, nanostructure, and properties (thermal, mechanical, and conducting) of tandem repeat squid-inspired protein materials are examined. Spectroscopic structural analysis, advanced materials characterization, and entropic elasticity theory are combined to elucidate the structure and material properties of these repetitive proteins. This approach is applied not only to native squid proteins but also to squid-inspired synthetic polypeptides that allow for a fine control of the sequence and network morphology. The results provided in this work establish a clear dependence between the repetitive building blocks, the network morphology, and the properties of squid-inspired repetitive protein materials. Increasing the number of tandem repeat units in SRT-inspired proteins led to more effective protein networks with superior properties. Through increasing tandem repetition and optimization of network morphology, highly efficient protein materials capable of withstanding deformations up to 400% of their original length, with MPa-GPa modulus, high energy absorption (50 MJ m-3), peak proton conductivity of 3.7 mS cm-1 (at pH 7, highest reported to date for biological materials), and peak thermal conductivity of 1.4 W m-1 K -1 (which exceeds that of most polymer materials) were developed. These findings introduce new design rules in the engineering of proteins based on tandem repetition and morphology control, and provide a novel framework for tailoring and optimizing the properties of protein-based materials.

Sonography of the chest using linear-array versus sector transducers: Correlation with auscultation, chest radiography, and computed tomography.

PubMed

Tasci, Ozlem; Hatipoglu, Osman Nuri; Cagli, Bekir; Ermis, Veli

2016-07-08

The primary purpose of our study was to compare the efficacies of two sonographic (US) probes, a high-frequency linear-array probe and a lower-frequency phased-array sector probe in the diagnosis of basic thoracic pathologies. The secondary purpose was to compare the diagnostic performance of thoracic US with auscultation and chest radiography (CXR) using thoracic CT as a gold standard. In total, 55 consecutive patients scheduled for thoracic CT were enrolled in this prospective study. Four pathologic entities were evaluated: pneumothorax, pleural effusion, consolidation, and interstitial syndrome. A portable US scanner was used with a 5-10-MHz linear-array probe and a 1-5-MHz phased-array sector probe. The first probe used was chosen randomly. US, CXR, and auscultation results were compared with the CT results. The linear-array probe had the highest performance in the identification of pneumothorax (83% sensitivity, 100% specificity, and 99% diagnostic accuracy) and pleural effusion (100% sensitivity, 97% specificity, and 98% diagnostic accuracy); the sector probe had the highest performance in the identification of consolidation (89% sensitivity, 100% specificity, and 95% diagnostic accuracy) and interstitial syndrome (94% sensitivity, 93% specificity, and 94% diagnostic accuracy). For all pathologies, the performance of US was superior to those of CXR and auscultation. The linear probe is superior to the sector probe for identifying pleural pathologies, whereas the sector probe is superior to the linear probe for identifying parenchymal pathologies. Thoracic US has better diagnostic performance than CXR and auscultation for the diagnosis of common pathologic conditions of the chest. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:383-389, 2016. © 2016 Wiley Periodicals, Inc.

A K-Band Linear Phased Array Antenna Based on Ba(0.60)Sr(0.40)TiO3 Thin Film Phase Shifters

NASA Technical Reports Server (NTRS)

Romanofsky, R.; Bernhard, J.; Washington, G.; VanKeuls, F.; Miranda, F.; Cannedy, C.

2000-01-01

This paper summarizes the development of a 23.675 GHz linear 16-element scanning phased array antenna based on thin ferroelectric film coupled microstripline phase shifters and microstrip patch radiators.

A Dry-Etch Process for Low Temperature Superconducting Transition Edge Sensors for Far Infrared Bolometer Arrays

NASA Technical Reports Server (NTRS)

Allen, Christine A.; Chervenak, James A.; Hsieh, Wen-Ting; McClanahan, Richard A.; Miller, Timothy M.; Mitchell, Robert; Moseley, S. Harvey; Staguhn, Johannes; Stevenson, Thomas R.

2003-01-01

The next generation of ultra-low power bolometer arrays, with applications in far infrared imaging, spectroscopy and polarimetry, utilizes a superconducting bilayer as the sensing element to enable SQUID multiplexed readout. Superconducting transition edge sensors (TES s) are being produced with dual metal systems of superconductinghormal bilayers. The transition temperature (Tc) is tuned by altering the relative thickness of the superconductor with respect to the normal layer. We are currently investigating MoAu and MoCu bilayers. We have developed a dry-etching process for MoAu TES s with integrated molybdenum leads, and are working on adapting the process to MoCu. Dry etching has the advantage over wet etching in the MoAu system in that one can achieve a high degree of selectivity, greater than 10, using argon ME, or argon ion milling, for patterning gold on molybdenum. Molybdenum leads are subsequently patterned using fluorine plasma.. The dry-etch technique results in a smooth, featureless TES with sharp sidewalls, no undercutting of the Mo beneath the normal metal, and Mo leads with high critical current. The effects of individual processing parameters on the characteristics of the transition will be reported.

A Rapid Turnaround Cryogenic Detector Characterization System

NASA Technical Reports Server (NTRS)

Benford, Dominic j.; Dipirro, Michael J.; Forgione, Joshua B.; Jackson, Clifton E.; Jackson, Michael L.; Kogut, Al; Moseley, S. Harvey; Shirron, Peter J.

2004-01-01

Upcoming major NASA missions such as the Einstein Inflation Probe and the Single Aperture Far-Infrared Observatory require arrays of detectors with thousands of elements, operating at temperatures near l00 mK and sensitive to wavelengths from approx. 100 microns to approx. 3 mm. Such detectors represent a substantial enabling technology for these missions, and must be demonstrated soon in order for them to proceed. In order to make rapid progress on detector development, the cryogenic testing cycle must be made convenient and quick. We have developed a cryogenic detector characterization system capable of testing superconducting detector arrays in formats up to 8 x 32, read out by SQUID multiplexers. The system relies on the cooling of a two-stage adiabatic demagnetization refrigerator immersed in a liquid helium bath. This approach permits a detector to be cooled from 300K to 50 mK in about 4 hours, so that a test cycle begun in the morning will be over by the end of the day. Tine system is modular, with two identical immersible units, so that while one unit is cooling, the second can be reconfigured for the next battery of tests. We describe the design, construction, and performance of this cryogenic detector testing facility.

Development of a Real-Time Pulse Processing Algorithm for TES-Based X-Ray Microcalorimeters

NASA Technical Reports Server (NTRS)

Tan, Hui; Hennig, Wolfgang; Warburton, William K.; Doriese, W. Bertrand; Kilbourne, Caroline A.

2011-01-01

We report here a real-time pulse processing algorithm for superconducting transition-edge sensor (TES) based x-ray microcalorimeters. TES-based. microca1orimeters offer ultra-high energy resolutions, but the small volume of each pixel requires that large arrays of identical microcalorimeter pixe1s be built to achieve sufficient detection efficiency. That in turn requires as much pulse processing as possible must be performed at the front end of readout electronics to avoid transferring large amounts of data to a host computer for post-processing. Therefore, a real-time pulse processing algorithm that not only can be implemented in the readout electronics but also achieve satisfactory energy resolutions is desired. We have developed an algorithm that can be easily implemented. in hardware. We then tested the algorithm offline using several data sets acquired with an 8 x 8 Goddard TES x-ray calorimeter array and 2x16 NIST time-division SQUID multiplexer. We obtained an average energy resolution of close to 3.0 eV at 6 keV for the multiplexed pixels while preserving over 99% of the events in the data sets.

Micromachined poly-SiGe bolometer arrays for infrared imaging and spectroscopy

NASA Astrophysics Data System (ADS)

Leonov, Vladimir N.; Perova, Natalia A.; De Moor, Piet; Du Bois, Bert; Goessens, Claus; Grietens, Bob; Verbist, Agnes; Van Hoof, Chris A.; Vermeiren, Jan P.

2003-03-01

The state-of-the-art characteristics of micromachined polycrystalline SiGe microbolometer arrays are reported. An average NETD of 85 mK at a time constant of 14 ms is already achievable on typical self-supported 50 μm pixels in a linear 64-element array. In order to reach these values, the design optimization was performed based on the performance characteristics of linear 32-, 64- and 128-element arrays of 50-, 60- and 75-μm-pixel bolometers on several detector lots. The infrared and thermal modeling accounting for the read-out properties and self-heating effect in bolometers resulted in improved designs and competitive NETD values of 80 mK on 50 μm pixels in a 160x128 format at standard frame rates and f-number of 1. In parallel, the TCR-to-1/f noise ratio and the mechanical design of the pixels were improved making poly-SiGe a good candidate for a low-cost uncooled thermal array. The technological CMOS-based process possesses an attractive balance between characteristics and price, and allows the micromachining of thin structures, less than 0.2 μm. The resistance and TCR non-uniformity with σ/μ better than 0.2% combined with 99.93% yield are demonstrated. The first lots of fully processed linear arrays have already come from the IMEC process line and the results of characterization are presented. Next year, the first linear and small 2D arrays will be introduced on the market.

Sequential isotopic signature along gladius highlights contrasted individual foraging strategies of jumbo squid (Dosidicus gigas).

PubMed

Lorrain, Anne; Argüelles, Juan; Alegre, Ana; Bertrand, Arnaud; Munaron, Jean-Marie; Richard, Pierre; Cherel, Yves

2011-01-01

Cephalopods play a major role in marine ecosystems, but knowledge of their feeding ecology is limited. In particular, intra- and inter-individual variations in their use of resources has not been adequatly explored, although there is growing evidence that individual organisms can vary considerably in the way they use their habitats and resources. Using δ(13)C and δ(15)N values of serially sampled gladius (an archival tissue), we examined high resolution variations in the trophic niche of five large (>60 cm mantle length) jumbo squids (Dosidicus gigas) that were collected off the coast of Peru. We report the first evidence of large inter-individual differences in jumbo squid foraging strategies with no systematic increase of trophic level with size. Overall, gladius δ(13)C values indicated one or several migrations through the squid's lifetime (∼8-9 months), during which δ(15)N values also fluctuated (range: 1 to 5‰). One individual showed an unexpected terminal 4.6‰ δ(15)N decrease (more than one trophic level), thus indicating a shift from higher- to lower-trophic level prey at that time. The data illustrate the high diversity of prey types and foraging histories of this species at the individual level. The isotopic signature of gladii proved to be a powerful tool to depict high resolution and ontogenic variations in individual foraging strategies of squids, thus complementing traditional information offered by stomach content analysis and stable isotopes on metabolically active tissues. The observed differences in life history strategies highlight the high degree of plasticity of the jumbo squid and its high potential to adapt to environmental changes.

Sequential Isotopic Signature Along Gladius Highlights Contrasted Individual Foraging Strategies of Jumbo Squid (Dosidicus gigas)

PubMed Central

Lorrain, Anne; Argüelles, Juan; Alegre, Ana; Bertrand, Arnaud; Munaron, Jean-Marie; Richard, Pierre; Cherel, Yves

2011-01-01

Background Cephalopods play a major role in marine ecosystems, but knowledge of their feeding ecology is limited. In particular, intra- and inter-individual variations in their use of resources has not been adequatly explored, although there is growing evidence that individual organisms can vary considerably in the way they use their habitats and resources. Methodology/Principal Findings Using δ13C and δ15N values of serially sampled gladius (an archival tissue), we examined high resolution variations in the trophic niche of five large (>60 cm mantle length) jumbo squids (Dosidicus gigas) that were collected off the coast of Peru. We report the first evidence of large inter-individual differences in jumbo squid foraging strategies with no systematic increase of trophic level with size. Overall, gladius δ13C values indicated one or several migrations through the squid's lifetime (∼8–9 months), during which δ15N values also fluctuated (range: 1 to 5‰). One individual showed an unexpected terminal 4.6‰ δ15N decrease (more than one trophic level), thus indicating a shift from higher- to lower-trophic level prey at that time. The data illustrate the high diversity of prey types and foraging histories of this species at the individual level. Conclusions/Significance The isotopic signature of gladii proved to be a powerful tool to depict high resolution and ontogenic variations in individual foraging strategies of squids, thus complementing traditional information offered by stomach content analysis and stable isotopes on metabolically active tissues. The observed differences in life history strategies highlight the high degree of plasticity of the jumbo squid and its high potential to adapt to environmental changes. PMID:21779391

Impacts of extensive driftnet fishery and late 1990s climate regime shift on dominant epipelagic nekton in the Transition Region and Subtropical Frontal Zone: Implications for fishery management

NASA Astrophysics Data System (ADS)

Ichii, T.; Nishikawa, H.; Igarashi, H.; Okamura, H.; Mahapatra, K.; Sakai, M.; Wakabayashi, T.; Inagake, D.; Okada, Y.

2017-01-01

We investigated the impacts of extensive anthropogenic (high seas driftnet squid fishery) and natural (late 1990s major climate regime shift) events on dominant epipelagic fish, squid, and shark in the central North Pacific Transition Region based on a driftnet survey covering the years 1979-2006. Fishing was conducted by Japan, Korea and Taiwan to target neon flying squid in the period 1979-1992, resulting in a decline in stocks of the target species and non-target species (Pacific pomfret and juvenile blue shark), which were by-catch of this fishery. The catch was found to be at the maximum sustainable yield (MSY) level for neon flying squid, the underfished level for juvenile blue shark, but the overfished level for Pacific pomfret. The MSY of Pacific pomfret indicated that this species is more susceptible to exploitation than previously considered. In response to the late 1990s regime shift, neon flying squid and Pacific saury showed low stock levels in 1999-2002 and 1998-2002, respectively, as a result of reduced productivity in their nursery grounds (the Subtropical Frontal Zone and Kuroshio Extension Bifurcation Region, respectively). On the other hand, Pacific pomfret showed no decreasing trend in stock during the low- and intermediate-productivity regimes because of the high productivity of their main spawning/nursery ground (Transition Zone Chlorophyll Front), which was independent of the regime shifts. Thus, squid and saury appear to be more susceptible to the regime shift than pomfret. We discuss the implications for stock management of the species-specific responses to the fishery and the regime shift.

Co-Prime Frequency and Aperture Design for HF Surveillance, Wideband Radar Imaging, and Nonstationary Array Processing

DTIC Science & Technology

2018-03-01

offset designs . Particularly, the proposed CA-CFO is compared with uniform linear array and uniform frequency offset (ULA-UFO). Uniform linear array...and Aperture Design for HF Surveillance, Wideband Radar Imaging, and Nonstationary Array Processing (Grant No. N00014-13-1-0061) Submitted to...Contents 1. Executive Summary …………………………………………………………………………. 1 1.1. Generalized Co-Prime Array Design ………………………………………………… 1 1.2. Wideband

The DCU: the detector control unit for SPICA-SAFARI

NASA Astrophysics Data System (ADS)

Clénet, Antoine; Ravera, Laurent; Bertrand, Bernard; den Hartog, Roland H.; Jackson, Brian D.; van Leeuven, Bert-Joost; van Loon, Dennis; Parot, Yann; Pointecouteau, Etienne; Sournac, Anthony

2014-08-01

IRAP is developing the warm electronic, so called Detector Control Unit" (DCU), in charge of the readout of the SPICA-SAFARI's TES type detectors. The architecture of the electronics used to readout the 3 500 sensors of the 3 focal plane arrays is based on the frequency domain multiplexing technique (FDM). In each of the 24 detection channels the data of up to 160 pixels are multiplexed in frequency domain between 1 and 3:3 MHz. The DCU provides the AC signals to voltage-bias the detectors; it demodulates the detectors data which are readout in the cold by a SQUID; and it computes a feedback signal for the SQUID to linearize the detection chain in order to optimize its dynamic range. The feedback is computed with a specific technique, so called baseband feedback (BBFB) which ensures that the loop is stable even with long propagation and processing delays (i.e. several µs) and with fast signals (i.e. frequency carriers at 3:3 MHz). This digital signal processing is complex and has to be done at the same time for the 3 500 pixels. It thus requires an optimisation of the power consumption. We took the advantage of the relatively reduced science signal bandwidth (i.e. 20 - 40 Hz) to decouple the signal sampling frequency (10 MHz) and the data processing rate. Thanks to this method we managed to reduce the total number of operations per second and thus the power consumption of the digital processing circuit by a factor of 10. Moreover we used time multiplexing techniques to share the resources of the circuit (e.g. a single BBFB module processes 32 pixels). The current version of the firmware is under validation in a Xilinx Virtex 5 FPGA, the final version will be developed in a space qualified digital ASIC. Beyond the firmware architecture the optimization of the instrument concerns the characterization routines and the definition of the optimal parameters. Indeed the operation of the detection and readout chains requires to properly define more than 17 500 parameters (about 5 parameters per pixel). Thus it is mandatory to work out an automatic procedure to set up these optimal values. We defined a fast algorithm which characterizes the phase correction to be applied by the BBFB firmware and the pixel resonance frequencies. We also defined a technique to define the AC-carrier initial phases in such a way that the amplitude of their sum is minimized (for a better use of the DAC dynamic range).

Magnetic Microcalorimeter (MMC) Gamma Detectors with Ultra-High Energy Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedrich, Stephen

The goal of this LCP is to develop ultra-high resolution gamma detectors based on magnetic microcalorimeters (MMCs) for accurate non-destructive analysis (NDA) of nuclear materials. For highest energy resolution, we will introduce erbium-doped silver (Ag:Er) as a novel sensor material, and implement several geometry and design changes to improve the signal-to-noise ratio. The detector sensitivity will be increased by developing arrays of 32 Ag:Er pixels read out by 16 SQUID preamplifiers, and by developing a cryogenic Compton veto to reduce the spectral background. Since best MMC performance requires detector operation at ~10 mK, we will purchase a dilution refrigerator withmore » a base temperature <10 mK and adapt it for MMC operation. The detector performance will be tested with radioactive sources of interest to the safeguards community.« less

Mixed Linear/Square-Root Encoded Single Slope Ramp Provides a Fast, Low Noise Analog to Digital Converter with Very High Linearity for Focal Plane Arrays

NASA Technical Reports Server (NTRS)

Wrigley, Christopher James (Inventor); Hancock, Bruce R. (Inventor); Cunningham, Thomas J. (Inventor); Newton, Kenneth W. (Inventor)

2014-01-01

An analog-to-digital converter (ADC) converts pixel voltages from a CMOS image into a digital output. A voltage ramp generator generates a voltage ramp that has a linear first portion and a non-linear second portion. A digital output generator generates a digital output based on the voltage ramp, the pixel voltages, and comparator output from an array of comparators that compare the voltage ramp to the pixel voltages. A return lookup table linearizes the digital output values.

Squid Dissection: From Pen to Ink.

ERIC Educational Resources Information Center

Brown, Cindy; Kisiel, Jim

2003-01-01

Introduces students to dissection, which is an important part of scientific discovery. Students not only gain an understanding of the anatomy of a squid, but also develop a sense of responsibility and respect for the animal that they are using as a learning tool. (Author/SOE)

Detection of buried magnetic objects by a SQUID gradiometer system

NASA Astrophysics Data System (ADS)

Meyer, Hans-Georg; Hartung, Konrad; Linzen, Sven; Schneider, Michael; Stolz, Ronny; Fried, Wolfgang; Hauspurg, Sebastian

2009-05-01

We present a magnetic detection system based on superconducting gradiometric sensors (SQUID gradiometers). The system provides a unique fast mapping of large areas with a high resolution of the magnetic field gradient as well as the local position. A main part of this work is the localization and classification of magnetic objects in the ground by automatic interpretation of geomagnetic field gradients, measured by the SQUID system. In accordance with specific features the field is decomposed into segments, which allow inferences to possible objects in the ground. The global consideration of object describing properties and their optimization using error minimization methods allows the reconstruction of superimposed features and detection of buried objects. The analysis system of measured geomagnetic fields works fully automatically. By a given surface of area-measured gradients the algorithm determines within numerical limits the absolute position of objects including depth with sub-pixel accuracy and allows an arbitrary position and attitude of sources. Several SQUID gradiometer data sets were used to show the applicability of the analysis algorithm.

Utilization of squid pen for the efficient production of chitosanase and antioxidants through prolonged autoclave treatment.

PubMed

Wang, San-Lang; Wu, Pei-Chen; Liang, Tzu-Wen

2009-05-26

We have developed a culture system for efficient production of chitosanase by Bacillus sp. TKU004. TKU004 was cultivated by using squid pen powder as the sole carbon/nitrogen source. The effects of autoclave treatments of the medium on the production of chitosanase were investigated. Autoclave treatment of squid pen powder for 45 min remarkably promoted enzyme productivity. When the culture medium containing an initial squid pen powder concentration of 3% was autoclaved for 45 min, the chitosanase activity was optimal and reached 0.14-0.16 U/mL. In addition, extracellular surfactant-stable chitosanase was purified from the TKU004 culture supernatant. The antioxidant activity of TKU004 culture supernatant was determined through the scavenging ability of DPPH, with 70% per mL. With this method, we have shown that marine wastes can be utilized efficiently through prolonged autoclave treatments to generate a high value-added product, and have revealed its hidden potential in the production of functional foods.

Eddy-Current-Based Nondestructive Inspection System Using Superconducting Quantum Interference Device for Thin Copper Tubes

NASA Astrophysics Data System (ADS)

Hatsukade, Yoshimi; Kosugi, Akifumi; Mori, Kazuaki; Tanaka, Saburo

2004-11-01

An eddy-current-based nondestructive inspection (NDI) system using superconducting quantum interference device (SQUID) cooled using a coaxial pulse tube cryocooler was constructed for the inspection of microflaws on copper tubes employing a high-Tc SQUID gradiometer and a Helmholtz-like coil inducer. The detection of artificial flaws several tens of μm in depth on copper tubes 6.35 mm in outer diameter and 0.825 mm in thickness was demonstrated using the SQUID-NDI system. With an excitation field of 1.6 μT at 5 kHz, a 30-μm-depth flaw was successfully detected by the system at an SN ratio of at least 20. The magnetic signal amplitude due to the flaw was proportional to both excitation frequency and the square of flaw depth. With consideration of the system’s sensitivity, the results indicate that sub-10-μm-depth flaws are detectable by the SQUID-NDI system.

Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

NASA Astrophysics Data System (ADS)

Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

2018-07-01

In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 {μ Φ }_0/Hz^{1/2}.

SQUIDs vs. Induction Coils for Ultra-Low Field Nuclear Magnetic Resonance: Experimental and Simulation Comparison

PubMed Central

Matlashov, Andrei N.; Schultz, Larry J.; Espy, Michelle A.; Kraus, Robert H.; Savukov, Igor M.; Volegov, Petr L.; Wurden, Caroline J.

2011-01-01

Nuclear magnetic resonance (NMR) is widely used in medicine, chemistry and industry. One application area is magnetic resonance imaging (MRI). Recently it has become possible to perform NMR and MRI in the ultra-low field (ULF) regime requiring measurement field strengths of the order of only 1 Gauss. This technique exploits the advantages offered by superconducting quantum interference devices or SQUIDs. Our group has built SQUID based MRI systems for brain imaging and for liquid explosives detection at airport security checkpoints. The requirement for liquid helium cooling limits potential applications of ULF MRI for liquid identification and security purposes. Our experimental comparative investigation shows that room temperature inductive magnetometers may provide enough sensitivity in the 3–10 kHz range and can be used for fast liquid explosives detection based on ULF NMR technique. We describe experimental and computer-simulation results comparing multichannel SQUID based and induction coils based instruments that are capable of performing ULF MRI for liquid identification. PMID:21747638

Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz

DOE Office of Scientific and Technical Information (OSTI.GOV)

TonThat, D.M.; Clarke, J.

1996-08-01

A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux lockedmore » operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect {sup 27}Al NQR signals in ruby (Al{sub 2}O{sub 3}[Cr{sup 3+}]) at 359 and 714 kHz. {copyright} {ital 1996 American Institute of Physics.}« less

Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

NASA Astrophysics Data System (ADS)

Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

2018-03-01

In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 μΦ_0/Hz^{1/2}.

Slow swimming, fast strikes: effects of feeding behavior on scaling of anaerobic metabolism in epipelagic squid.

PubMed

Trueblood, Lloyd A; Seibel, Brad A

2014-08-01

Many pelagic fishes engage prey at high speeds supported by high metabolic rates and anaerobic metabolic capacity. Epipelagic squids are reported to have among the highest metabolic rates in the oceans as a result of demanding foraging strategies and the use of jet propulsion, which is inherently inefficient. This study examined enzymatic proxies of anaerobic metabolism in two species of pelagic squid, Dosidicus gigas and Doryteuthis pealeii (Lesueur 1821), over a size range of six orders of magnitude. We hypothesized that activity of the anaerobically poised enzymes would be high and increase with size as in ecologically similar fishes. In contrast, we demonstrate that anaerobic metabolic capacity in these organisms scales negatively with body mass. We explored several cephalopod-specific traits, such as the use of tentacles to capture prey, body morphology and reduced relative prey size of adult squids, that may create a diminished reliance on anaerobically fueled burst activity during prey capture in large animals. © 2014. Published by The Company of Biologists Ltd.

Production and functional evaluation of a protein concentrate from giant squid (Dosidicus gigas) by acid dissolution and isoelectric precipitation.

PubMed

Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Elena Lugo-Sánchez, M; Gisela Carvallo-Ruiz, M; García-Sánchez, Guillermina

2008-09-15

A protein concentrate from giant squid (Dosidicus gigas) was produced under acidic conditions and its functional-technological capability evaluated in terms of its gel-forming ability, water holding capacity and colour attributes. Technological functionality of the concentrate was compared with that of squid muscle and a neutral concentrate. Protein-protein aggregates insoluble at high ionic strength (I=0.5M), were detected in the acidic concentrate as result of processing with no preclusion of its gel-forming ability during the sol-to-gel thermal transition. Even though washing under acidic condition promoted autolysis of the myosin heavy chain, the acidic concentrate displayed an outstanding ability to gel giving samples with a gel strength of 455 and 1160gcm at 75% and 90% compression respectively, and an AA folding test grade indicative of high gel strength, elasticity, and cohesiveness. The process proved to be a good alternative for obtaining a functional protein concentrate from giant squid muscle. Copyright © 2008. Published by Elsevier Ltd.

Microwave photon generation in a doubly tunable superconducting resonator

NASA Astrophysics Data System (ADS)

Svensson, I.-M.; Pierre, M.; Simoen, M.; Wustmann, W.; Krantz, P.; Bengtsson, A.; Johansson, G.; Bylander, J.; Shumeiko, V.; Delsing, P.

2018-03-01

We have created a doubly tunable resonator, with the intention to simulate relativistic motion of the resonator boundaries in real space. Our device is a superconducting coplanar-waveguide microwave resonator, with fundamental resonant frequency ω 1 /(2π) ~ 5 GHz. Both of its ends are terminated to ground via dc-SQUIDs, which serve as magnetic-flux-controlled inductances. Applying a flux to either SQUID allows the tuning of ω 1 /(2π) by approximately 700 MHz. Using two separate on-chip magnetic-flux lines, we modulate the SQUIDs with two tones of equal frequency, close to 2ω 1. We observe photon generation, at ω 1, above a certain pump amplitude threshold. By varying the relative phase of the two pumps we are able to control this threshold, in good agreement with a theoretical model. At the same time, some of our observations deviate from the theoretical predictions, which we attribute to parasitic couplings resulting in current driving of the SQUIDs.

Development of non-destructive evaluation system using an HTS-SQUID gradiometer for magnetized materials

NASA Astrophysics Data System (ADS)

Kawano, J.; Tsukamoto, A.; Adachi, S.; Oshikubo, Y.; Hato, T.; Tanabe, K.; Okamura, T.

We have developed a new eddy-current non-destructive evaluation (NDE) system using an HTS SQUID gradiometer with the aim of applying it to practical materials with magnetization. The new NDE system employs a LN2-cooled external Cu pickup coil and an HTS SQUID chip placed in a magnetic shield made of HTS material. The HTS SQUID chip consists of an HTS planar gradiometer manufactured by using a ramp-edge junction technology and a multi-turn HTS thin film input coil coupled with the flip-chip configuration. The first-order coaxial gradiometric Cu pickup coil with a diameter of 16 mm and the baseline of 5.6 mm was used in the present NDE experiments. By using this NDE system, we could observe defect-induced magnetic signals without an appreciable influence of magnetization up to 10 mT. We also examined the ability of detecting deep-lying defects and compared with the results obtained using our previous NDE system.

Fast photoacoustic imaging system based on 320-element linear transducer array.

PubMed

Yin, Bangzheng; Xing, Da; Wang, Yi; Zeng, Yaguang; Tan, Yi; Chen, Qun

2004-04-07

A fast photoacoustic (PA) imaging system, based on a 320-transducer linear array, was developed and tested on a tissue phantom. To reconstruct a test tomographic image, 64 time-domain PA signals were acquired from a tissue phantom with embedded light-absorption targets. A signal acquisition was accomplished by utilizing 11 phase-controlled sub-arrays, each consisting of four transducers. The results show that the system can rapidly map the optical absorption of a tissue phantom and effectively detect the embedded light-absorbing target. By utilizing the multi-element linear transducer array and phase-controlled imaging algorithm, we thus can acquire PA tomography more efficiently, compared to other existing technology and algorithms. The methodology and equipment thus provide a rapid and reliable approach to PA imaging that may have potential applications in noninvasive imaging and clinic diagnosis.

Highly Directive Array Aperture

DTIC Science & Technology

2013-02-13

generally to sonar arrays with acoustic discontinuities, and, more particularly, to increasing the directivity gain of a sonar array aperture by...sought by sonar designers. [0005] The following patents and publication show various types of acoustic arrays with coatings and discontinuities that...discloses a sonar array uses multiple acoustically transparent layers. One layer is a linear array of acoustic sensors that is substantially

Diet and stable isotope analyses reveal the feeding ecology of the orangeback squid Sthenoteuthis pteropus (Steenstrup 1855) (Mollusca, Ommastrephidae) in the eastern tropical Atlantic.

PubMed

Merten, Véronique; Christiansen, Bernd; Javidpour, Jamileh; Piatkowski, Uwe; Puebla, Oscar; Gasca, Rebeca; Hoving, Henk-Jan T

2017-01-01

In the eastern tropical Atlantic, the orangeback flying squid Sthenoteuthis pteropus (Steenstrup 1855) (Cephalopoda, Ommastrephidae) is a dominant species of the epipelagic nekton community. This carnivore squid has a short lifespan and is one of the fastest-growing squids. In this study, we characterise the role of S. pteropus in the pelagic food web of the eastern tropical Atlantic by investigating its diet and the dynamics of its feeding habits throughout its ontogeny and migration. During three expeditions in the eastern tropical Atlantic in 2015, 129 specimens were caught by hand jigging. Stomach content analyses (via visual identification and DNA barcoding) were combined with stable isotope data (∂15N and ∂13C) of muscle tissue to describe diet, feeding habits and trophic ecology of S. pteropus. Additionally, stable isotope analyses of incremental samples along the squid's gladius-the chitinous spiniform structure supporting the muscles and organs-were carried out to explore possible diet shifts through ontogeny and migration. Our results show that S. pteropus preys mainly on myctophid fishes (e.g. Myctophum asperum, Myctophum nitidulum, Vinciguerria spp.), but also on other teleost species, cephalopods (e.g. Enoploteuthidae, Bolitinidae, Ommastrephidae), crustaceans and possibly on gelatinous zooplankton as well. The squid shows a highly opportunistic feeding behaviour that includes cannibalism. Our study indicates that the trophic position of S. pteropus may increase by approximately one trophic level from a mantle length of 15 cm to 47 cm. The reconstructed isotope-based feeding chronologies of the gladii revealed high intra- and inter-individual variability in the squid's trophic position and foraging area. These findings are not revealed by diet or muscle tissue stable isotope analysis. This suggests a variable and complex life history involving individual variation and migration. The role of S. pteropus in transferring energy and nutrients from lower to higher trophic levels may be underestimated and important for understanding how a changing ocean impacts food webs in the eastern Atlantic.

White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

NASA Astrophysics Data System (ADS)

Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

2014-06-01

White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 104 ≤ Q ≤ 2 × 104 and the square root of spectral density of current noise referred to the SQUID input √SI = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers PMR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √SI is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of PMR) or the quantization noise due to the resolution of 300-K electronics (for large values of PMR). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit √SI ≤ 5 pA/√Hz, i.e., close to √SI of state-of-the-art DC-SQUID-based multiplexers.

Variability of Suitable Habitat of Western Winter-Spring Cohort for Neon Flying Squid in the Northwest Pacific under Anomalous Environments.

PubMed

Yu, Wei; Chen, Xinjun; Yi, Qian; Chen, Yong; Zhang, Yang

2015-01-01

We developed a habitat suitability index (HSI) model to evaluate the variability of suitable habitat for neon flying squid (Ommastrephes bartramii) under anomalous environments in the Northwest Pacific Ocean. Commercial fisheries data from the Chinese squid-jigging vessels on the traditional fishing ground bounded by 35°-45°N and 150°-175°E from July to November during 1998-2009 were used for analyses, as well as the environmental variables including sea surface temperature (SST), chlorophyll-a (Chl-a) concentration, sea surface height anomaly (SSHA) and sea surface salinity (SSS). Two empirical HSI models (arithmetic mean model, AMM; geometric mean model, GMM) were established according to the frequency distribution of fishing efforts. The AMM model was found to perform better than the GMM model. The AMM-based HSI model was further validated by the fishery and environmental data in 2010. The predicted HSI values in 1998 (high catch), 2008 (average catch) and 2009 (low catch) indicated that the squid habitat quality was strongly associated with the ENSO-induced variability in the oceanic conditions on the fishing ground. The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii. While the fishing ground in the El Niño year of 2009 experienced anomalous cool waters and unfavorable range of Chl-a concentration and SSHA, leading to relatively low-quality squid habitats. Our findings suggest that the La Niña event in 1998 tended to result in more favorable habitats for O. bartramii in the Northwest Pacific with the gravity centers of fishing efforts falling within the defined suitable habitat and yielding high squid catch; whereas the El Niño event in 2009 yielded less favorable habitat areas with the fishing effort distribution mismatching the suitable habitat and a dramatic decline of the catch of O. bartramii. This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change.

Variability of Suitable Habitat of Western Winter-Spring Cohort for Neon Flying Squid in the Northwest Pacific under Anomalous Environments

PubMed Central

Yu, Wei; Chen, Xinjun; Yi, Qian; Chen, Yong; Zhang, Yang

2015-01-01

We developed a habitat suitability index (HSI) model to evaluate the variability of suitable habitat for neon flying squid (Ommastrephes bartramii) under anomalous environments in the Northwest Pacific Ocean. Commercial fisheries data from the Chinese squid-jigging vessels on the traditional fishing ground bounded by 35°-45°N and 150°-175°E from July to November during 1998-2009 were used for analyses, as well as the environmental variables including sea surface temperature (SST), chlorophyll-a (Chl-a) concentration, sea surface height anomaly (SSHA) and sea surface salinity (SSS). Two empirical HSI models (arithmetic mean model, AMM; geometric mean model, GMM) were established according to the frequency distribution of fishing efforts. The AMM model was found to perform better than the GMM model. The AMM-based HSI model was further validated by the fishery and environmental data in 2010. The predicted HSI values in 1998 (high catch), 2008 (average catch) and 2009 (low catch) indicated that the squid habitat quality was strongly associated with the ENSO-induced variability in the oceanic conditions on the fishing ground. The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii. While the fishing ground in the El Niño year of 2009 experienced anomalous cool waters and unfavorable range of Chl-a concentration and SSHA, leading to relatively low-quality squid habitats. Our findings suggest that the La Niña event in 1998 tended to result in more favorable habitats for O. bartramii in the Northwest Pacific with the gravity centers of fishing efforts falling within the defined suitable habitat and yielding high squid catch; whereas the El Niño event in 2009 yielded less favorable habitat areas with the fishing effort distribution mismatching the suitable habitat and a dramatic decline of the catch of O. bartramii. This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change. PMID:25923519

The pace of life in deep-dwelling squids

NASA Astrophysics Data System (ADS)

Hoving, H. J. T.; Robison, B. H.

2017-08-01

Coastal and epipelagic cephalopods are among the fastest growing invertebrates, with life cycles of typically 1 year or less. Evidence is accumulating that deep-sea taxa often live longer and grow slower than their shallow water relatives. We test the hypothesis that deep-sea squid show increased longevity and reduced growth rates compared to coastal and epipelagic species, by validation experiments and quantification of statolith increments of three deep-sea squids from the Monterey Submarine Canyon. The periodicity of statolith increment formation in coastal species is daily, but is unknown for deep-sea squid. Between 2010 and 2013, specimens of Chiroteuthis calyx, Galiteuthis phyllura and Octopoteuthis deletron were captured by remotely operated vehicles and trawl nets off California. ROV-captured living squid were immersed in tetracycline and kept alive in the lab for between 3 and 14 days. Correlating the number of elapsed days with the number of newly deposited statolith increments, and statolith growth after the fluorescent tetracycline mark, provided evidence of regular and daily increment deposition, in C. calyx and O. deletron. This relationship was less strong in G. phyllura and the one-increment-per-day hypothesis was not accepted for this species. Reconstructing growth rates based on statolith counts and wet weights from animals of a wide size range suggest that O. deletron is a slower growing squid (0.59% BW/day) than C. calyx (1.3% BW/day) and G. phyllura (1.2% BW/day). Octopoteuthis deletron matures at around two years, the oldest C. calyx was a mature male of 1.5 years and the eldest G. phyllura was 10 months and still immature. Maximum reported sizes for G. phyllura and C. calyx exceed those of our examined specimens, and therefore their longevity likely exceeds 2 years, in particular if the females brood their eggs. Our study supports the hypothesis that deeper living squid exhibit reduced growth rates and an increased longevity compared to shallow living species. We discuss these traits in the context of a life in the deep pelagic ocean.

Ontogenetic and Experience-Dependent Changes in Defensive Behavior in Captive-Bred Hawaiian Bobtail Squid, Euprymna scolopes

PubMed Central

Seehafer, Kia; Brophy, Samantha; Tom, Sara R.; Crook, Robyn J.

2018-01-01

Cephalopod molluscs are known for their extensive behavioral repertoire and their impressive learning abilities. Their primary defensive behaviors, such as camouflage, have received detailed study, but knowledge is limited to intensive study of relatively few species. A considerable challenge facing cephalopod research is the need to establish new models that can be captive bred, are tractable for range of different experimental procedures, and that will address broad questions in biological research. The Hawaiian Bobtail Squid (Euprymna scolopes) is a small, tropical cephalopod that has a long history of research in the field of microbial symbiosis, but offers great promise as a novel behavioral and neurobiological model. It can be bred in the laboratory through multiple generations, one of the few species of cephalopod that can meet this requirement (which is incorporated in regulations such as EU directive 2010/63/EU). Additionally, laboratory culture makes E. scolopes an ideal model for studying ontogeny- and experience-dependent behaviors. In this study, we show that captive bred juvenile and adult E. scolopes produce robust, repeatable defensive behaviors when placed in an exposed environment and presented with a visual threat. Further, adult and juvenile squid employ different innate defensive behaviors when presented with a size-matched model predator. When a 10-min training procedure was repeated over three consecutive days, defensive behaviors habituated in juvenile squid for at least 5 days after training, but memory did not appear to persist for 14 days. In contrast, adult squid did not show any evidence of long-term habituation memory. Thus we conclude that this species produces a range of quantifiable, modifiable behaviors even in a laboratory environment where ecologically-relevant, complex behavioral sequences may not reliably occur. We suggest that the lack of long-term memory in adult squid may be related to their less escalated initial response to the mimic, and thus indicates less motivation to retain memory and not necessary inability to form memory. This is the first demonstration of age-related differences in defensive behaviors in Euprymna, and the first record of habituation in this experimentally tractable genus of squid. PMID:29651249

Space-Time Adaptive Processing for Airborne Radar

DTIC Science & Technology

1994-12-13

horizontal plane Uniform linear antenna array (possibly columns of a planar array) Identical element patterns 13 14 15 9 7 7,33 7 7 Target Model ...Parameters for Example Scenario 31 3 Assumptions Made for Radar System and Signal Model 52 4 Platform and Interference Scenario for Baseline Scenario. 61 5...pulses, is addressed first. Fully adaptive STAP requires the solution to a system of linear equations of size MN, where N is the number of array

High-performance linear arrays of YBa2Cu3O7 superconducting infrared microbolometers on silicon

NASA Astrophysics Data System (ADS)

Johnson, Burgess R.; Foote, Marc C.; Marsh, Holly A.

1995-06-01

Single detectors and linear arrays of microbolometers utilizing the superconducting transition edge of YBa(subscript 2)Cu(subscript 3)O(subscript 7) have been fabricated by micromachining on silicon wafers. A D* of 8 +/- 2 X 10(superscript 9) cm Hz(superscript 1/2)/watt has been measured on a single detector. This is the highest D* reported on any superconducting microbolometer operating at temperatures higher than about 70 K. The NEP of this device was 1.5 X 10(superscript -12) watts/Hz(superscript HLF) at 2 Hz, at a temperature of 80.7 K. The thermal time constant was 105 msec, and the detector area was 140 micrometers X 105 micrometers . The use of batch silicon processing makes fabrication of linear arrays of these detectors relatively straightforward. The measured responsivity of detectors in one such array varied by less than 20% over the 6 mm length of the 64-element linear array. This measurement shows that good uniformity can be achieved at a single operating temperature in a superconductor microbolometer array, even when the superconducting resistive transition is a sharp function of temperature. The thermal detection mechanism of these devices gives them broadband response. This makes them especially useful at long wavelengths (e.g. (lambda) > 20 micrometers ), where they provide very high sensitivity at relatively high operating temperatures.

Foods of northern fulmars associated with high-seas drift nets in the transitional region of the North Pacific

USGS Publications Warehouse

Gould, Patrick J.; Walker, William; Ostrom, Peggy H.

1997-01-01

We examined digestive tract contents and nitrogen stable isotope ratios in breast muscles of northern fulmars (Fulmarus glacialis) salvaged from squid and large-mesh drift nets in the transitional North Pacific. Lantern fishes (Myctophidae) were the principal prey item found in the digestive tracts. Pieces of unidentified fishes (probably Pacific pomfret Brama japonica) and shredded squid tissue (probably neon flying squid Ommastrephes bartrami) indicate scavenging at fishing operations. Although soft-bodied prey such as Velella were not found in the digestive tracts, δ 15N values suggest that fulmars may feed heavily on such low trophic-level animals.

The Anatomy and Morphology of the Adult Bacterial Light Organ of Euprymna scolopes Berry (Cephalopoda:Sepiolidae).

PubMed

McFall-Ngai, M; Montgomery, M K

1990-12-01

The sepiolid squid, Euprymna scolopes, has a bilobed luminous organ in the center of the mantle cavity, associated with the ink sac. Luminous bacterial symbionts (Vibrio fischeri) are housed in narrow channels of host epithelial tissue. The channels of each lobe of the light organ empty into a ciliated duct, which is contiguous with the mantle cavity of the squid. Surrounding the symbiotic bacteria and their supportive host cells are host tissues recruited into the light organ system, including a muscle-derived lens and thick reflector that appear to permit the squid to control the quality of bacterial light emission.

Characterization of Kerfless Linear Arrays Based on PZT Thick Film.

PubMed

Zawada, Tomasz; Bierregaard, Louise Moller; Ringgaard, Erling; Xu, Ruichao; Guizzetti, Michele; Levassort, Franck; Certon, Dominique

2017-09-01

Multielement transducers enabling novel cost-effective fabrication of imaging arrays for medical applications have been presented earlier. Due to the favorable low lateral coupling of the screen-printed PZT, the elements can be defined by the top electrode pattern only, leading to a kerfless design with low crosstalk between the elements. The thick-film-based linear arrays have proved to be compatible with a commercial ultrasonic scanner and to support linear array beamforming as well as phased array beamforming. The main objective of the presented work is to investigate the performance of the devices at the transducer level by extensive measurements of the test structures. The arrays have been characterized by several different measurement techniques. First, electrical impedance measurements on several elements in air and liquid have been conducted in order to support material parameter identification using the Krimholtz-Leedom-Matthaei model. It has been found that electromechanical coupling is at the level of 35%. The arrays have also been characterized by a pulse-echo system. The measured sensitivity is around -60 dB, and the fractional bandwidth is close to 60%, while the center frequency is about 12 MHz over the whole array. Finally, laser interferometry measurements have been conducted indicating very good displacement level as well as pressure. The in-depth characterization of the array structure has given insight into the performance parameters for the array based on PZT thick film, and the obtained information will be used to optimize the key parameters for the next generation of cost-effective arrays based on piezoelectric thick film.

One Period of Exploration with the Squid.

ERIC Educational Resources Information Center

Bradley, James V.; Ng, Andrew

1997-01-01

Presents a lab that can be offered after students have learned the basic anatomy and physiology of the various phyla, the primary objective of which is to explore and apply their acquired knowledge to a new situation. Involves exploring the anatomy and life-style of the squid. (JRH)

Compact integrated dc SQUID gradiometer

NASA Astrophysics Data System (ADS)

de Waal, V. J.; Klapwijk, T. M.

1982-10-01

An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17×12 mm and a sensitivity of 3.5×10-12 T m-1 Hz-1/2.

50 CFR 648.25 - Atlantic Mackerel, squid, and butterfish framework adjustments to management measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... framework adjustments to management measures. 648.25 Section 648.25 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES... Butterfish Fisheries § 648.25 Atlantic Mackerel, squid, and butterfish framework adjustments to management...

50 CFR 648.25 - Atlantic Mackerel, squid, and butterfish framework adjustments to management measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... framework adjustments to management measures. 648.25 Section 648.25 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES... Butterfish Fisheries § 648.25 Atlantic Mackerel, squid, and butterfish framework adjustments to management...

50 CFR 648.25 - Atlantic Mackerel, squid, and butterfish framework adjustments to management measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... framework adjustments to management measures. 648.25 Section 648.25 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES... Butterfish Fisheries § 648.25 Atlantic Mackerel, squid, and butterfish framework adjustments to management...

EVOLUTIONARY PERSPECTIVES IN A MUTUALISM OF SEPIOLID SQUID AND BIOLUMINESCENT BACTERIA: COMBINED USAGE OF MICROBIAL EXPERIMENTAL EVOLUTION AND TEMPORAL POPULATION GENETICS

PubMed Central

Soto, W.; Punke, E. B.; Nishiguchi, M. K.

2013-01-01

The symbiosis between marine bioluminescent Vibrio bacteria and the sepiolid squid Euprymna is a model for studying animal–bacterial Interactions. Vibrio symbionts native to particular Euprymna species are competitively dominant, capable of outcompeting foreign Vibrio strains from other Euprymna host species. Despite competitive dominance, secondary colonization events by invading nonnative Vibrio fischeri have occurred. Competitive dominance can be offset through superior nonnative numbers and advantage of early start host colonization by nonnatives, granting nonnative vibrios an opportunity to establish beachheads in foreign Euprymna hosts. Here, we show that nonnative V. fischeri are capable of rapid adaptation to novel sepiolid squid hosts by serially passaging V. fischeri JRM200 (native to Hawaiian Euprymna scolopes) lines through the novel Australian squid host E. tasmanica for 500 generations. These experiments were complemented by a temporal population genetics survey of V. fischeri, collected from E. tasmanica over a decade, which provided a perspective from the natural history of V. fischeri evolution over 15,000–20,000 generations in E. tasmanica. No symbiont anagenic evolution within squids was observed, as competitive dominance does not purge V. fischeri genetic diversity through time. Instead, abiotic factors affecting abundance of V. fischeri variants in the planktonic phase sustain temporal symbiont diversity, a property itself of ecological constraints imposed by V. fischeri host adaptation. PMID:22519773

Muscular tissues of the squid Doryteuthis pealeii express identical myosin heavy chain isoforms: an alternative mechanism for tuning contractile speed

PubMed Central

Shaffer, Justin F.; Kier, William M.

2012-01-01

SUMMARY The speed of muscle contraction is largely controlled at the sarcomere level by the ATPase activity of the motor protein myosin. Differences in amino acid sequence in catalytically important regions of myosin yield different myosin isoforms with varying ATPase activities and resulting differences in cross-bridge cycling rates and interfilamentary sliding velocities. Modulation of whole-muscle performance by changes in myosin isoform ATPase activity is regarded as a universal mechanism to tune contractile properties, especially in vertebrate muscles. Invertebrates such as squid, however, may exhibit an alternative mechanism to tune contractile properties that is based on differences in muscle ultrastructure, including variable myofilament and sarcomere lengths. To determine definitively whether contractile properties of squid muscles are regulated via different myosin isoforms (i.e. different ATPase activities), the nucleotide and amino acid sequences of the myosin heavy chain from the squid Doryteuthis pealeii were determined from the mantle, arm, tentacle, fin and funnel retractor musculature. We identified three myosin heavy chain isoforms in squid muscular tissues, with differences arising at surface loop 1 and the carboxy terminus. All three isoforms were detected in all five tissues studied. These results suggest that the muscular tissues of D. pealeii express identical myosin isoforms, and it is likely that differences in muscle ultrastructure, not myosin ATPase activity, represent the most important mechanism for tuning contractile speeds. PMID:22189767

Squid 'ear bones' (statoliths) from the Jurassic succession of South-west England

NASA Astrophysics Data System (ADS)

Hart, Malcolm; Page, Kevin; Price, Gregory; Smart, Christopher

2015-04-01

Squid 'ear bones' - or statoliths - are a part of the balancing organs of modern and probably most fossil squids. Over the course of the last 10 years fossil statoliths have been discovered in the Jurassic sediments of the Wessex Basin (South-west England). They are probably all related to teuthids, such as Belemnotheutis antiquus Pearce, of Callovian-Oxfordian age. Thus far, we have identified four possible 'species' of statolith that are in the process of being formally described, named and their potential relationships determined. The sediments from which these statoliths have been recorded also contain squid hooklets (onycites), otoliths (fish 'ear bones') and other microfossils (including foraminifera). All are, therefore, of marine origin. In the case of the Christian Malford and Ashton Keynes lagerstätte (of late Callovian age), the statoliths are associated with exceptional, soft-bodied preservation of squid and it may be possible to determine the parent animal of the recorded statoliths. A number of museum collections (Natural History Museum [London], Natural History Museum [Paris], Senckenberg [Frankfurt], Smithsonian Institution [Washington], etc.) are being investigated in order to trace the possible host animals for all of the recorded statoliths. Despite many thousands of samples of Cretaceous sediments being investigated for foraminifera over the past 40+ years, no statoliths have been recorded and none are known from the literature.

A quantum description of linear, and non-linear optical interactions in arrays of plasmonic nanoparticles

NASA Astrophysics Data System (ADS)

Arabahmadi, Ehsan; Ahmadi, Zabihollah; Rashidian, Bizhan

2018-06-01

A quantum theory for describing the interaction of photons and plasmons, in one- and two-dimensional arrays is presented. Ohmic losses and inter-band transitions are not considered. We use macroscopic approach, and quantum field theory methods including S-matrix expansion, and Feynman diagrams for this purpose. Non-linear interactions are also studied, and increasing the probability of such interactions, and its application are also discussed.

Novel Approaches to Quantum Computation Using Solid State Qubits

DTIC Science & Technology

2007-12-31

hysteretic DC-SQUIDs, Phys. Rev. B 71, 220509(R) (2005). 18. C.-P. Yang and S. Han, Generation of Greenberger-Horne- Zeilinger entangled states with three SQUID...Horne- Zeilinger entangled states with multiple superconducting quantum interference device qubits/atoms in cavity QED, Phys. Rev. A 70, 062323 (2004

75 FR 5537 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

... Butterfish Fisheries; Specifications and Management Measures AGENCY: National Marine Fisheries Service (NMFS... implements 2010 specifications and management measures for Atlantic mackerel, squid, and butterfish (MSB... (Loligo), and butterfish at the same levels as 2009. This action also modifies accounting procedures for...

75 FR 37739 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-30

.... This action complies with the 2010 Specifications and Management Measures for the Atlantic Mackerel, Squid, and Butterfish Fisheries Management Plan, which modified accounting procedures for underages of... FURTHER INFORMATION CONTACT: Lindsey Feldman, Fishery Management Specialist, 978-675-2179, Fax 978-281...

50 CFR 635.5 - Recordkeeping and reporting.

Code of Federal Regulations, 2011 CFR

2011-10-01

.../headboat vessel, an Atlantic tunas vessel, a shark vessel, a swordfish vessel, or a vessel in the squid... fish landed and discarded. Entries on a day's fishing activities must be entered on the logbook form.../headboat vessel, Atlantic tunas vessel, shark vessel, swordfish vessel, or a vessel in the squid trawl...

Microfossil evidence for a mid-Jurassic squid egg-laying area in association with the Christian Malford Lagerstätte

NASA Astrophysics Data System (ADS)

Hart, Malcolm; de Jonghe, Alex; Duff, Keith; Page, Kevin; Price, Gregory; Smart, Christopher; Wilby, Philip

2010-05-01

In the 1840s, during the construction of the Great Western Railway west of Swindon, a number of beautifully preserved coleoids (belemnites and squid-like cephalopods) were found. These famous specimens of Belemnoteuthis and Mastigophora, as well as a number of fish, were eventually described as a fossil lagerstätte under the name of the "Christian Malford Squid Bed". Many of these specimens, which come from the Phaeinum Zone (Callovian) of the Oxford Clay Formation, contain soft tissue, muscle fibres and the content of their ink sacs. In October 2007 the British Geological Survey funded an excavation of the site some ~100 m from the original borrow pits alongside the railway. This pit yielded some new coleoid specimens as well as many ammonites, bivalves and gastropods, all of which are exquisitely preserved. Some of the bedding surfaces recovered are plastered with monospecific assemblages of foraminifera (In the 1840s, during the construction of the Great Western Railway west of Swindon, a number of beautifully preserved coleoids (belemnites and squid-like cephalopods) were found. These famous specimens of Belemnoteuthis and Mastigophora, as well as a number of fish, were eventually described as a fossil lagerstätte under the name of the "Christian Malford Squid Bed". Many of these specimens, which come from the Phaeinum Zone (Callovian) of the Oxford Clay Formation, contain soft tissue, muscle fibres and the content of their ink sacs. In October 2007 the British Geological Survey funded an excavation of the site some ~100 m from the original borrow pits alongside the railway. This pit yielded some new coleoid specimens as well as many ammonites, bivalves and gastropods, all of which are exquisitely preserved. Some of the bedding surfaces recovered are plastered with monospecific assemblages of foraminifera (Epistomina spp.). Our work on borehole core No. 10 (from the same location) has recovered exceptionally large numbers of statoliths, otoliths (fish ‘ear' bones), squid hooks and foraminifera. Statoliths are the small, paired, aragonitic stones found in the heads of modern and fossil coleoids. Jurassic statoliths have yet to be described in any detail as there is only one reference to them in the literature (Clarke, 2003). The exceptional abundance of statoliths and squid hooks recorded in the samples from the core is thought to represent a Jurassic squid-breeding ground which existed for a substantial interval of late Callovian time. The annual spawning of female squids massively enlarges their ovaries and this breaks down the body wall leaving spent individuals to die. The lack of belemnites in the same strata suggests that the animals involved (unknown at present) did not possess a calcified "guard". The highest numbers of statoliths occur over a 3 m thickness of strata with the greatest abundance ~1 m below the Christian Malford Squid Bed. The numbers recorded in this part of the Phaeinum Zone are well above background levels in the rest of the Jurassic in the UK (Malcolm Clarke, pers.com.) where one has to wash several kg of sediment to recover <200 statoliths. The occurrence of abundant, though low diversity, foraminiferal assemblages in the same samples point to an oxic, though possibly stressed, environment. The significant proportion of deformed foraminifera in the assemblages appears to confirm that the environment was less than optimum. CLARKE, M.R. 2003. Potential of statoliths for interpreting coleoid evolution: A brief review. Berliner Paläobiol. Abh., 3, 37-47.

A chemiluminescence sensor array for discriminating natural sugars and artificial sweeteners.

PubMed

Niu, Weifen; Kong, Hao; Wang, He; Zhang, Yantu; Zhang, Sichun; Zhang, Xinrong

2012-01-01

In this paper, we report a chemiluminescence (CL) sensor array based on catalytic nanomaterials for the discrimination of ten sweeteners, including five natural sugars and five artificial sweeteners. The CL response patterns ("fingerprints") can be obtained for a given compound on the nanomaterial array and then identified through linear discriminant analysis (LDA). Moreover, each pure sweetener was quantified based on the emission intensities of selected sensor elements. The linear ranges for these sweeteners lie within 0.05-100 mM, but vary with the type of sweetener. The applicability of this array to real-life samples was demonstrated by applying it to various beverages, and the results showed that the sensor array possesses excellent discrimination power and reversibility.

Performance analysis of structured gradient algorithm. [for adaptive beamforming linear arrays

NASA Technical Reports Server (NTRS)

Godara, Lal C.

1990-01-01

The structured gradient algorithm uses a structured estimate of the array correlation matrix (ACM) to estimate the gradient required for the constrained least-mean-square (LMS) algorithm. This structure reflects the structure of the exact array correlation matrix for an equispaced linear array and is obtained by spatial averaging of the elements of the noisy correlation matrix. In its standard form the LMS algorithm does not exploit the structure of the array correlation matrix. The gradient is estimated by multiplying the array output with the receiver outputs. An analysis of the two algorithms is presented to show that the covariance of the gradient estimated by the structured method is less sensitive to the look direction signal than that estimated by the standard method. The effect of the number of elements on the signal sensitivity of the two algorithms is studied.

The effect of Nb additions on the thermal stability of melt-spun Nd2Fe14B

NASA Astrophysics Data System (ADS)

Lewis, L. H.; Gallagher, K.; Panchanathan, V.

1999-04-01

Elevated-temperature superconducting quantum interference device (SQUID) magnetometry was performed on two samples of melt-spun and optimally annealed Nd2Fe14B; one sample contained 2.3 wt % Nb and one was Nb-free. Continuous full hysteresis loops were measured with a SQUID magnetometer at T=630 K, above the Curie temperature of the 2-14-1 phase, as a function of field (1 T⩽H⩽-1 T) and time on powdered samples sealed in quartz tubes at a vacuum of 10-6 Torr. The measured hysteresis signals were deconstructed into a high-field linear paramagnetic portion and a low-field ferromagnetic signal of unclear origin. While the saturation magnetization of the ferromagnetic signal from both samples grows with time, the signal from the Nb-containing sample is always smaller. The coercivity data are consistent with a constant impurity particle size in the Nb-containing sample and an increasing impurity particle size in the Nb-free sample. The paramagnetic susceptibility signal from the Nd2Fe14B-type phase in the Nb-free sample increases with time, while that from the Nb-containing sample remains constant. It is suggested that the presence of Nb actively suppresses the thermally induced formation of poorly crystallized Fe-rich regions that apparently exist in samples of both compositions.

Development of microwave-multiplexed superconductive detectors for the HOLMES experiment

NASA Astrophysics Data System (ADS)

Giachero, A.; Becker, D.; Bennett, D. A.; Faverzani, M.; Ferri, E.; Fowler, J. W.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Maino, M.; Mates, J. A. B.; Puiu, A.; Nucciotti, A.; Reintsema, C. D.; Swetz, D. S.; Ullom, J. N.; Vale, L. R.

2016-05-01

In recent years, the progress on low temperature detector technologies has allowed design of large scale experiments aiming at pushing down the sensitivity on the neutrino mass below 1 eV. Even with outstanding performances in both energy (~eV on keV) and time resolution (~ 1 μs) on the single channel, a large number of detectors working in parallel is required to reach a sub-eV sensitivity. HOLMES is a new experiment to directly measure the neutrino mass with a sensitivity as low as 2eV. HOLMES will perform a calorimetric measurement of the energy released in the electron capture (EC) decay of 163 Ho. In its final configuration, HOLMES will deploy 1000 detectors of low temperature microcalorimeters with implanted 163 Ho nuclei. The baseline sensors for HOLMES are Mo/Cu TESs (Transition Edge Sensors) on SiNx membrane with gold absorbers. The readout is based on the use of rf-SQUIDs as input devices with flux ramp modulation for linearization purposes; the rf-SQUID is then coupled to a superconducting lambda/4-wave resonator in the GHz range, and the modulated signal is finally read out using the homodyne technique. The TES detectors have been designed with the aim of achieving an energy resolution of a few eV at the spectrum endpoint and a time resolution of a few micro-seconds, in order to minimize pile-up artifacts.

Comparison of the Roche Cobas(®) 4800 HPV assay to Digene Hybrid Capture 2, Roche Linear Array and Roche Amplicor for Detection of High-Risk Human Papillomavirus Genotypes in Women undergoing treatment for cervical dysplasia.

PubMed

Phillips, Samuel; Garland, Suzanne M; Tan, Jeffery H; Quinn, Michael A; Tabrizi, Sepehr N

2015-01-01

The recently FDA (U.S. food and drug administration) approved Roche Cobas(®) 4800 (Cobas) human papillomavirus (HPV) has limited performance data compared to current HPV detection methods for test of cure in women undergoing treatment for high grade lesions. Evaluation of Cobas HPV assay using historical samples from women undergoing treatment for cervical dysplasia. A selection of 407 samples was tested on the Cobas assay and compared to previous results from Hybrid Capture 2, HPV Amplicor and Roche Linear Array. Overall, a correlation between high-risk HPV positivity and high grade histological diagnosis was 90.6% by the Cobas, 86.1% by Hybrid Capture 2, 92.9% by HPV Amplicor and 91.8% by Roche Linear Array. The Cobas HPV assay is comparative to both the HPV Amplicor and Roche Linear Array assays and better than Hybrid capture 2 assay in the detection of High-Risk HPV in women undergoing treatment for cervical dysplasia. Copyright © 2014 Elsevier B.V. All rights reserved.

Linear micromechanical stepping drive for pinhole array positioning

NASA Astrophysics Data System (ADS)

Endrödy, Csaba; Mehner, Hannes; Grewe, Adrian; Hoffmann, Martin

2015-05-01

A compact linear micromechanical stepping drive for positioning a 7 × 5.5 mm2 optical pinhole array is presented. The system features a step size of 13.2 µm and a full displacement range of 200 µm. The electrostatic inch-worm stepping mechanism shows a compact design capable of positioning a payload 50% of its own weight. The stepping drive movement, step sizes and position accuracy are characterized. The actuated pinhole array is integrated in a confocal chromatic hyperspectral imaging system, where coverage of the object plane, and therefore the useful picture data, can be multiplied by 14 in contrast to a non-actuated array.

Segmented amplifier configurations for laser amplifier

DOEpatents

Hagen, Wilhelm F.

1979-01-01

An amplifier system for high power lasers, the system comprising a compact array of segments which (1) preserves high, large signal gain with improved pumping efficiency and (2) allows the total amplifier length to be shortened by as much as one order of magnitude. The system uses a three dimensional array of segments, with the plane of each segment being oriented at substantially the amplifier medium Brewster angle relative to the incident laser beam and with one or more linear arrays of flashlamps positioned between adjacent rows of amplifier segments, with the plane of the linear array of flashlamps being substantially parallel to the beam propagation direction.

Advanced Antenna-Coupled Superconducting Detector Arrays for CMB Polarimetry

NASA Astrophysics Data System (ADS)

Bock, James

2014-01-01

We are developing high-sensitivity millimeter-wave detector arrays for measuring the polarization of the cosmic microwave background (CMB). This development is directed to advance the technology readiness of the Inflation Probe mission in NASA's Physics of the Cosmos program. The Inflation Probe is a fourth-generation CMB satellite that will measure the polarization of the CMB to astrophysical limits, characterizing the inflationary polarization signal, mapping large-scale structure based on polarization induced by gravitational lensing, and mapping Galactic magnetic fields through measurements of polarized dust emission. The inflationary polarization signal is produced by a background of gravitational waves from the epoch of inflation, an exponential expansion of space-time in the early universe, with an amplitude that depends on the physical mechanism producing inflation. The inflationary polarization signal may be distinguished by its unique 'B-mode' vector properties from polarization from the density variations that predominantly source CMB temperature anisotropy. Mission concepts for the Inflation Probe are being developed in the US, Europe and Japan. The arrays are based on planar antennas that provide integral beam collimation, polarization analysis, and spectral band definition in a compact lithographed format that eliminates discrete fore-optics such as lenses and feedhorns. The antennas are coupled to transition-edge superconducting bolometers, read out with multiplexed SQUID current amplifiers. The superconducting sensors and readouts developed in this program share common technologies with NASA X-ray and FIR detector applications. Our program targets developments required for space observations, and we discuss our technical progress over the past two years and plans for future development. We are incorporating arrays into active sub-orbital and ground-based experiments, which advance technology readiness while producing state of the art CMB polarization measurements.

Resolving Phase Ambiguities in the Calibration of Redundant Interferometric Arrays: Implications for Array Design

DTIC Science & Technology

2016-03-04

summary of the linear algebra involved. As we have seen, the RSC process begins with the interferometric phase measurement β, which due to wrapping will...mentary Divisors) in Section 2 and the following defi- nition of the matrix determinant. This definition is given in many linear algebra texts (see...principle solve for a particular solution of this system by arbitrarily setting two object phases (whose spatial frequencies are not co- linear ) and one

A Fast Method to Calculate the Spatial Impulse Response for 1-D Linear Ultrasonic Phased Array Transducers

PubMed Central

Zou, Cheng; Sun, Zhenguo; Cai, Dong; Muhammad, Salman; Zhang, Wenzeng; Chen, Qiang

2016-01-01

A method is developed to accurately determine the spatial impulse response at the specifically discretized observation points in the radiated field of 1-D linear ultrasonic phased array transducers with great efficiency. In contrast, the previously adopted solutions only optimize the calculation procedure for a single rectangular transducer and required approximation considerations or nonlinear calculation. In this research, an algorithm that follows an alternative approach to expedite the calculation of the spatial impulse response of a rectangular linear array is presented. The key assumption for this algorithm is that the transducer apertures are identical and linearly distributed on an infinite rigid plane baffled with the same pitch. Two points in the observation field, which have the same position relative to two transducer apertures, share the same spatial impulse response that contributed from corresponding transducer, respectively. The observation field is discretized specifically to meet the relationship of equality. The analytical expressions of the proposed algorithm, based on the specific selection of the observation points, are derived to remove redundant calculations. In order to measure the proposed methodology, the simulation results obtained from the proposed method and the classical summation method are compared. The outcomes demonstrate that the proposed strategy can speed up the calculation procedure since it accelerates the speed-up ratio which relies upon the number of discrete points and the number of the array transducers. This development will be valuable in the development of advanced and faster linear ultrasonic phased array systems. PMID:27834799

Numerical restoration of surface vortices in Nb films measured by a scanning SQUID microscope

NASA Astrophysics Data System (ADS)

Ito, Atsuki; Thanh Huy, Ho; Dang, Vu The; Miyoshi, Hiroki; Hayashi, Masahiko; Ishida, Takekazu

2017-07-01

In the present work, we investigated a vortex profile appeared on a pure Nb film (500 nm in thickness, 10 mm x 10 mm) by using a scanning SQUID microscope. We found that the local magnetic distribution thus observed is broadened compared to a true vortex profile in the superconducting film. We therefore applied the numerical method to improve a spatial resolution of the scanning SQUID microscope. The method is based on the inverse Biot-Savart law and the Fourier transformation to recover a real-space image. We found that the numerical analyses give a smaller vortex than the raw vortex profile observed by the scanning microscope.

A 400 KHz line rate 2048 pixel modular SWIR linear array for earth observation applications

NASA Astrophysics Data System (ADS)

Anchlia, Ankur; Vinella, Rosa M.; Wouters, Kristof; Gielen, Daphne; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; van der Zanden, Koen; Vermeiren, Jan; Merken, Patrick

2015-10-01

In this paper, we report about a family of linear imaging FPAs sensitive in the [0.9 - 1.7um] band, developed for high speed applications such as LIDAR, wavelength references and OCT analyzers and also for earth observation applications. Fast linear FPAs can also be used in a wide variety of terrestrial applications, including high speed sorting, electro- and photo-luminesce and medical applications. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. In principle, this concept can be extended to any multiple of 512 pixels, the limiting factor being the pixel yield of long InGaAs arrays and the CTE differences in the hybrid setup. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long-linear array to run at a high line rate of 400 KHz irrespective of the array length, which limits the line rate in a traditional linear array. The pixel has a pitch of 12.5um. The detector frontend is based on CTIA (Capacitor Trans-impedance Amplifier), having 5 selectable integration capacitors giving full well from 62x103e- (gain0) to 40x106e- (gain4). An auto-zero circuit limits the detector bias non-uniformity to 5-10mV across broad intensity levels, limiting the input referred dark signal noise to 20e-rms for Tint=3ms at room temperature. An on-chip CDS that follows the CTIA facilitates removal of Reset/KTC noise, CTIA offsets and most of the 1/f noise. The measured noise of the ROIC is 35e-rms in gain0. At a master clock rate of 60MHz and a minimum integration time of 1.4us, the FPAs reach the highest line rate of 400 KHz.

Enhanced focus steering abilities of multi-element therapeutic arrays operating in nonlinear regimes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuldashev, P., E-mail: petr@acs366.phys.msu.ru; Ilyin, S.; Gavrilov, L.

2015-10-28

Steering abilities of a typical HIFU therapeutic array operated in linear and nonlinear regimes were compared using numerical simulation with the 3D Westervelt equation. The array included 256 elements of 1.2 MHz frequency and 6.6 mm diameter distributed in a quasi-random pattern over a spherical shell with a 130 mm aperture and a focal length of 120 mm. In the case of linear focusing, thermal effects are proportional to the intensity level and the criterion for safe array operation is that the intensity in the grating lobes should be less than 10% of the intensity in the main focus. Inmore » the case of nonlinear focusing, the heating effect is no longer proportional to intensity; therefore the heat deposition rate was chosen as the relevant metric, using the same 10% threshold for the secondary lobe in comparison with the focal maximum. When steering the focus, the same linearly predicted intensity level at the main focus was maintained by increasing the array power. Numerical simulations of the acoustic field were performed for nonlinear propagation both in water and in tissue. It was shown that for shock-forming conditions in the main focus, the steering range of safe electronic focusing is larger than that for linear propagation conditions. Nonlinear sonication regimes therefore can be used to enlarge tissue volumes that can be sonicated using electronic steering of the focus of HIFU arrays.« less

76 FR 39313 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-06

.... 100804323-0569-02] RIN 0648-XA523 Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the Directed Butterfish Fishery AGENCY: National Marine Fisheries Service...; closure. SUMMARY: NMFS announces that the directed fishery for butterfish in the Exclusive Economic Zone...

Hydrolysates from scallop and squid processing byproducts as specialty aquafeed ingredients

USDA-ARS?s Scientific Manuscript database

Around 9,000 MT of squid (Loligo pealei) is landed annually in Rhode Island, USA, most of which is processed resulting in 40-50% unutilized byproducts (about 3,500 MT). On the other hand, the sea scallop (Placopecten magellanicus) resource off New England is currently at historic high levels of 22,7...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirtley, John R., E-mail: jkirtley@stanford.edu; Rosenberg, Aaron J.; Palmstrom, Johanna C.

Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ{sub 0}/Hz{sup 1/2}. This high spatial resolution is accomplished by deep sub-micron feature sizes, well shielded pickup loops fabricated using a planarized process, and a deep etch step that minimizes themore » spacing between the sample surface and the SQUID pickup loop. We describe the design, modeling, fabrication, and testing of these sensors. Although sub-micron spatial resolution has been achieved previously in scanning SQUID sensors, our sensors not only achieve high spatial resolution but also have integrated modulation coils for flux feedback, integrated field coils for susceptibility measurements, and batch processing. They are therefore a generally applicable tool for imaging sample magnetization, currents, and susceptibilities with higher spatial resolution than previous susceptometers.« less

Cosmological flux noise and measured noise power spectra in SQUIDs

PubMed Central

Beck, Christian

2016-01-01

The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe. PMID:27320418

Mass spectrometry analysis and transcriptome sequencing reveal glowing squid crystal proteins are in the same superfamily as firefly luciferase

PubMed Central

Gimenez, Gregory; Metcalf, Peter; Paterson, Neil G.; Sharpe, Miriam L.

2016-01-01

The Japanese firefly squid Hotaru-ika (Watasenia scintillans) produces intense blue light from photophores at the tips of two arms. These photophores are densely packed with protein microcrystals that catalyse the bioluminescent reaction using ATP and the substrate coelenterazine disulfate. The squid is the only organism known to produce light using protein crystals. We extracted microcrystals from arm tip photophores and identified the constituent proteins using mass spectrometry and transcriptome libraries prepared from arm tip tissue. The crystals contain three proteins, wsluc1–3, all members of the ANL superfamily of adenylating enzymes. They share 19 to 21% sequence identity with firefly luciferases, which produce light using ATP and the unrelated firefly luciferin substrate. We propose that wsluc1–3 form a complex that crystallises inside the squid photophores, and that in the crystal one or more of the proteins catalyses the production of light using coelenterazine disulfate and ATP. These results suggest that ANL superfamily enzymes have independently evolved in distant species to produce light using unrelated substrates. PMID:27279452

SQUIDs vs. Faraday coils for ultlra-low field nuclear magnetic resonance: experimental and simulation comparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matlashov, Andrei N; Espy, Michelle A; Kraus, Robert H

2010-01-01

Nuclear magnetic resonance (NMR) methods are widely used in medicine, chemistry and industry. One application area is magnetic resonance imaging or MRI. Recently it has become possible to perform NMR and MRI in ultra-low field (ULF) regime that requires measurement field strengths only of the order of 1 Gauss. These techniques exploit the advantages offered by superconducting quantum interference devices or SQUIDs. Our group at LANL has built SQUID based MRI systems for brain imaging and for liquid explosives detection at airports security checkpoints. The requirement for liquid helium cooling limits potential applications of ULF MRI for liquid identification andmore » security purposes. Our experimental comparative investigation shows that room temperature inductive magnetometers provide enough sensitivity in the 3-10 kHz range and can be used for fast liquid explosives detection based on ULF NMR/MRI technique. We describe an experimental and computer simulation comparison of the world's first multichannel SQUID based and Faraday coils based instruments that are capable of performing ULF MRI for liquids identification.« less

Body Size Regression Formulae, Proximate Composition and Energy Density of Eastern Bering Sea Mesopelagic Fish and Squid

PubMed Central

2015-01-01

The ecological significance of fish and squid of the mesopelagic zone (200 m–1000 m) is evident by their pervasiveness in the diets of a broad spectrum of upper pelagic predators including other fishes and squids, seabirds and marine mammals. As diel vertical migrators, mesopelagic micronekton are recognized as an important trophic link between the deep scattering layer and upper surface waters, yet fundamental aspects of the life history and energetic contribution to the food web for most are undescribed. Here, we present newly derived regression equations for 32 species of mesopelagic fish and squid based on the relationship between body size and the size of hard parts typically used to identify prey species in predator diet studies. We describe the proximate composition and energy density of 31 species collected in the eastern Bering Sea during May 1999 and 2000. Energy values are categorized by body size as a proxy for relative age and can be cross-referenced with the derived regression equations. Data are tabularized to facilitate direct application to predator diet studies and food web models. PMID:26287534

Adsorption of Pb(II) and Cd(II) by Squid Ommastrephes bartrami Melanin

PubMed Central

Chen, Shiguo; Xue, Changhu; Wang, Jingfeng; Feng, Hui; Wang, Yuming; Ma, Qin; Wang, Dongfeng

2009-01-01

The adsorption of Cd(II) and Pb(II) by squid melanin was investigated. At a metal ion concentration of 2 mM/L, the biosorption efficiency of melanin reached 95% for Cd(II) and Pb(II). The maximum content of bound Cd(II) and Pb(II) was 0.93 mM/g and 0.65 mM/g, respectively. Temperature had no obvious effect on the adsorption of the metals, and in a pH range of 4.0–7.0, the adsorption yield was high and stable. Macrosalts such as NaCl, MgCl2, and CaCl2 had no obvious effect on the binding of Pb(II) but greatly diminished the adsorption of Cd(II), which indicated that different functional groups in squid melanin are responsible for their adsorption. IR analysis of metal ion-enriched squid melanin demonstrated that the possible functional groups responsible for metal binding were phenolic hydroxyl (OH), carboxyl (COOH), and amine groups (NH). This study reports a new material for the removal of heavy metals from low-strength wastewater. PMID:20148082

Fabrication of YBa2Cu3O7 twin-boundary-junction dc SQUID by using a focused-ion-beam pattern technique

NASA Astrophysics Data System (ADS)

Lee, Sung Hoon; Lee, Soon-Gul

2017-09-01

We have fabricated YBa2Cu3O7 (YBCO) dc SQUIDs containing nanobridges across twin boundaries of LaAlO3 (LAO) substrates as Josephson elements by using a focused ion beam (FIB) etching method and measured their transport properties. The beam energy was 30 keV and the current was 1.5 pA for the nanobridge pattern. Each bridge with a nominal width of 200 nm crossed a twin boundary in the (100) direction. The SQUID loop had a 10 μm × 10 μm hole with a 5.7 μm average linewidth. The SQUID voltage showed modulations in response to the external flux with a maximum modulation depth of 350 μV at 77.0 K. HR-XRD spectra showed that the epitaxially grown YBCO film was twinned in commensurate with the twinning of the LAO substrate. Tilting of the c-axis of YBCO across the twin boundary is believed to play a role as a tunnel barrier.

Body Size Regression Formulae, Proximate Composition and Energy Density of Eastern Bering Sea Mesopelagic Fish and Squid.

PubMed

Sinclair, Elizabeth H; Walker, William A; Thomason, James R

2015-01-01

The ecological significance of fish and squid of the mesopelagic zone (200 m-1000 m) is evident by their pervasiveness in the diets of a broad spectrum of upper pelagic predators including other fishes and squids, seabirds and marine mammals. As diel vertical migrators, mesopelagic micronekton are recognized as an important trophic link between the deep scattering layer and upper surface waters, yet fundamental aspects of the life history and energetic contribution to the food web for most are undescribed. Here, we present newly derived regression equations for 32 species of mesopelagic fish and squid based on the relationship between body size and the size of hard parts typically used to identify prey species in predator diet studies. We describe the proximate composition and energy density of 31 species collected in the eastern Bering Sea during May 1999 and 2000. Energy values are categorized by body size as a proxy for relative age and can be cross-referenced with the derived regression equations. Data are tabularized to facilitate direct application to predator diet studies and food web models.

Cosmological flux noise and measured noise power spectra in SQUIDs.

PubMed

Beck, Christian

2016-06-20

The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe.

Development of a real-time, high-frequency ultrasound digital beamformer for high-frequency linear array transducers.

PubMed

Hu, Chang-Hong; Xu, Xiao-Chen; Cannata, Jonathan M; Yen, Jesse T; Shung, K Kirk

2006-02-01

A real-time digital beamformer for high-frequency (>20 MHz) linear ultrasonic arrays has been developed. The system can handle up to 64-element linear array transducers and excite 16 channels and receive simultaneously at 100 MHz sampling frequency with 8-bit precision. Radio frequency (RF) signals are digitized, delayed, and summed through a real-time digital beamformer, which is implemented using a field programmable gate array (FPGA). Using fractional delay filters, fine delays as small as 2 ns can be implemented. A frame rate of 30 frames per second is achieved. Wire phantom (20 microm tungsten) images were obtained and -6 dB axial and lateral widths were measured. The results showed that, using a 30 MHz, 48-element array with a pitch of 100 microm produced a -6 dB width of 68 microm in the axial and 370 microm in the lateral direction at 6.4 mm range. Images from an excised rabbit eye sample also were acquired, and fine anatomical structures, such as the cornea and lens, were resolved.

Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package.

PubMed

Rosen, Hannah; Gilly, William; Bell, Lauren; Abernathy, Kyler; Marshall, Greg

2015-01-15

Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed 'flashing' is characterized by a global oscillation (2-4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed 'flickering' was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species. © 2015. Published by The Company of Biologists Ltd.

Commercial squids: characterization, assessment of potential health benefits/risks and discrimination based on mineral, lipid and vitamin E concentrations.

PubMed

Torrinha, A; Gomes, F; Oliveira, M; Cruz, R; Mendes, E; Delerue-Matos, C; Casal, S; Morais, S

2014-05-01

The most consumed squid species worldwide were characterized regarding their concentrations of minerals, fatty acids, cholesterol and vitamin E. Interspecific comparisons were assessed among species and geographical origin. The health benefits derived from squid consumption were assessed based on daily minerals intake and on nutritional lipid quality indexes. Squids contribute significantly to daily intake of several macro (Na, K, Mg and P) and micronutrients (Cu, Zn and Ni). Despite their low fat concentration, they are rich in long-chain omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicosapentanoic (EPA) acids, with highly favorable ω-3/ω-6 ratios (from 5.7 to 17.7), reducing the significance of their high cholesterol concentration (140-549 mg/100g ww). Assessment of potential health risks based on minerals intake, non-carcinogenic and carcinogenic risks indicated that Loligo gahi (from Atlantic Ocean), Loligo opalescens (from Pacific Ocean) and Loligo duvaucelii (from Indic Ocean) should be eaten with moderation due to the high concentrations of Cu and/or Cd. Canonical discriminant analysis identified the major fatty acids (C14:0, C18:0, C18:1, C18:3ω-3, C20:4ω-6 and C22:5ω-6), P, K, Cu and vitamin E as chemical discriminators for the selected species. These elements and compounds exhibited the potential to prove authenticity of the commercially relevant squid species. Copyright © 2014 Elsevier Ltd. All rights reserved.

A proof of the Woodward-Lawson sampling method for a finite linear array

NASA Technical Reports Server (NTRS)

Somers, Gary A.

1993-01-01

An extension of the continuous aperture Woodward-Lawson sampling theorem has been developed for a finite linear array of equidistant identical elements with arbitrary excitations. It is shown that by sampling the array factor at a finite number of specified points in the far field, the exact array factor over all space can be efficiently reconstructed in closed form. The specified sample points lie in real space and hence are measurable provided that the interelement spacing is greater than approximately one half of a wavelength. This paper provides insight as to why the length parameter used in the sampling formulas for discrete arrays is larger than the physical span of the lattice points in contrast with the continuous aperture case where the length parameter is precisely the physical aperture length.

Design and calibration of a six-axis MEMS sensor array for use in scoliosis correction surgery

NASA Astrophysics Data System (ADS)

Benfield, David; Yue, Shichao; Lou, Edmond; Moussa, Walied A.

2014-08-01

A six-axis sensor array has been developed to quantify the 3D force and moment loads applied in scoliosis correction surgery. Initially this device was developed to be applied during scoliosis correction surgery and augmented onto existing surgical instrumentation, however, use as a general load sensor is also feasible. The development has included the design, microfabrication, deployment and calibration of a sensor array. The sensor array consists of four membrane devices, each containing piezoresistive sensing elements, generating a total of 16 differential voltage outputs. The calibration procedure has made use of a custom built load application frame, which allows quantified forces and moments to be applied and compared to the outputs from the sensor array. Linear or non-linear calibration equations are generated to convert the voltage outputs from the sensor array back into 3D force and moment information for display or analysis.

Transcriptome analysis of Nautilus and pygmy squid developing eye provides insights in lens and eye evolution.

PubMed

Sousounis, Konstantinos; Ogura, Atsushi; Tsonis, Panagiotis A

2013-01-01

Coleoid cephalopods like squids have a camera-type eye similar to vertebrates. On the other hand, Nautilus (Nautiloids) has a pinhole eye that lacks lens and cornea. Since pygmy squid and Nautilus are closely related species they are excellent model organisms to study eye evolution. Having being able to collect Nautilus embryos, we employed next-generation RNA sequencing using Nautilus and pygmy squid developing eyes. Their transcriptomes were compared and analyzed. Enrichment analysis of Gene Ontology revealed that contigs related to nucleic acid binding were largely up-regulated in squid, while the ones related to metabolic processes and extracellular matrix-related genes were up-regulated in Nautilus. These differences are most likely correlated with the complexity of tissue organization in these species. Moreover, when the analysis focused on the eye-related contigs several interesting patterns emerged. First, contigs from both species related to eye tissue differentiation and morphogenesis as well as to cilia showed best hits with their Human counterparts, while contigs related to rabdomeric photoreceptors showed the best hit with their Drosophila counterparts. This bolsters the idea that eye morphogenesis genes have been generally conserved in evolution, and compliments other studies showing that genes involved in photoreceptor differentiation clearly follow the diversification of invertebrate (rabdomeric) and vertebrate (ciliated) photoreceptors. Interestingly some contigs showed as good a hit with Drosophila and Human homologues in Nautilus and squid samples. One of them, capt/CAP1, is known to be preferentially expressed in Drosophila developing eye and in vertebrate lens. Importantly our analysis also provided evidence of gene duplication and diversification of their function in both species. One of these genes is the Neurofibromatosis 1 (NF1/Nf1), which in mice has been implicated in lens formation, suggesting a hitherto unsuspected role in the evolution of the lens in molluscs.

Transcriptome Analysis of Nautilus and Pygmy Squid Developing Eye Provides Insights in Lens and Eye Evolution

PubMed Central

Sousounis, Konstantinos; Ogura, Atsushi; Tsonis, Panagiotis A.

2013-01-01

Coleoid cephalopods like squids have a camera-type eye similar to vertebrates. On the other hand, Nautilus (Nautiloids) has a pinhole eye that lacks lens and cornea. Since pygmy squid and Nautilus are closely related species they are excellent model organisms to study eye evolution. Having being able to collect Nautilus embryos, we employed next-generation RNA sequencing using Nautilus and pygmy squid developing eyes. Their transcriptomes were compared and analyzed. Enrichment analysis of Gene Ontology revealed that contigs related to nucleic acid binding were largely up-regulated in squid, while the ones related to metabolic processes and extracellular matrix-related genes were up-regulated in Nautilus. These differences are most likely correlated with the complexity of tissue organization in these species. Moreover, when the analysis focused on the eye-related contigs several interesting patterns emerged. First, contigs from both species related to eye tissue differentiation and morphogenesis as well as to cilia showed best hits with their Human counterparts, while contigs related to rabdomeric photoreceptors showed the best hit with their Drosophila counterparts. This bolsters the idea that eye morphogenesis genes have been generally conserved in evolution, and compliments other studies showing that genes involved in photoreceptor differentiation clearly follow the diversification of invertebrate (rabdomeric) and vertebrate (ciliated) photoreceptors. Interestingly some contigs showed as good a hit with Drosophila and Human homologues in Nautilus and squid samples. One of them, capt/CAP1, is known to be preferentially expressed in Drosophila developing eye and in vertebrate lens. Importantly our analysis also provided evidence of gene duplication and diversification of their function in both species. One of these genes is the Neurofibromatosis 1 (NF1/Nf1), which in mice has been implicated in lens formation, suggesting a hitherto unsuspected role in the evolution of the lens in molluscs. PMID:24205087

Improved Sensing Coils for SQUIDs

NASA Technical Reports Server (NTRS)

Penanen, Konstantin; Hahn, Inseob; Eom, Byeong Ho

2007-01-01

An improvement in the design and fabrication of sensing coils of superconducting quantum interference device (SQUID) magnetometers has been proposed to increase sensitivity. It has been estimated that, in some cases, it would be possible to increase sensitivity by about half or to reduce measurement time correspondingly. The pertinent aspects of the problems of design and fabrication can be summarized as follows: In general, to increase the sensitivity of a SQUID magnetometer, it is necessary to maximize the magnetic flux enclosed by the sensing coil while minimizing the self-inductance of this coil. It is often beneficial to fabricate the coil from a thicker wire to reduce its self-inductance. Moreover, to optimize the design of the coil with respect to sensitivity, it may be necessary to shape the wire to other than a commonly available circular or square cross-section. On the other hand, it is not practical to use thicker superconducting wire for the entire superconducting circuit, especially if the design of a specific device requires a persistent-current loop enclosing a remotely placed SQUID sensor. It may be possible to bond a thicker sensing-coil wire to thinner superconducting wires leading to a SQUID sensor, but it could be difficult to ensure reliable superconducting connections, especially if the bonded wires are made of different materials. The main idea is to mold the sensing coil in place, to more nearly optimum cross sectional shape, instead of making the coil by winding standard pre-fabricated wire. For this purpose, a thin superconducting wire loop that is an essential part of the SQUID magnetometer would be encapsulated in a form that would serve as a mold. A low-melting-temperature superconducting metal (e.g., indium, tin, or a lead/tin alloy) would be melted into the form, which would be sized and shaped to impart the required cross section to the coil thus formed.

High-resolution imaging of magnetic fields using scanning superconducting quantum interference device (SQUID) microscopy

NASA Astrophysics Data System (ADS)

Fong de Los Santos, Luis E.

Development of a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with sub-millimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensor is mounted in the tip of a sapphire rod and thermally anchored to the cryostat helium reservoir. A 25 mum sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows adjusting the sample-to-sensor spacing from the top of the Dewar. I have achieved a sensor-to-sample spacing of 100 mum, which could be maintained for periods of up to 4 weeks. Different SQUID sensor configurations are necessary to achieve the best combination of spatial resolution and field sensitivity for a given magnetic source. For imaging thin sections of geological samples, I used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80 mum, and achieved a field sensitivity of 1.5 pT/Hz1/2 and a magnetic moment sensitivity of 5.4 x 10-18 Am2/Hz1/2 at a sensor-to-sample spacing of 100 mum in the white noise region for frequencies above 100 Hz. Imaging action currents in cardiac tissue requires higher field sensitivity, which can only be achieved by compromising spatial resolution. I developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250 mum to 1 mm, and achieved sensitivities of 480 - 180 fT/Hz1/2 in the white noise region for frequencies above 100 Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of geological samples.

Fishery biology of jumbo flying squid Dosidicus gigas off Costa Rica Dome

NASA Astrophysics Data System (ADS)

Chen, Xinjun; Li, Jianghua; Liu, Bilin; Li, Gang; Lu, Huajie

2014-06-01

The jumbo flying squid ( Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome (4°-11°N, 90°-100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°-9°N and 91°-94°W and by 6°30'-7°30'N and 96°-97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29°C. The sex ratio of the total catch was 3.75:1 (female: male). The mantle length of the squid ranged from 211 to 355 mm (male) and from 204 to 429 mm (female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length (mm) and body weight (g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size (mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs (70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.

Radar Resource Management in a Dense Target Environment

DTIC Science & Technology

2014-03-01

problem faced by networked MFRs . While relaxing our assumptions concerning information gain presents numerous challenges worth exploring, future research...linear programming MFR multifunction phased array radar MILP mixed integer linear programming NATO North Atlantic Treaty Organization PDF probability...1: INTRODUCTION Multifunction phased array radars ( MFRs ) are capable of performing various tasks in rapid succession. The performance of target search

Position sensor for linear synchronous motors employing halbach arrays

DOEpatents

Post, Richard Freeman

2014-12-23

A position sensor suitable for use in linear synchronous motor (LSM) drive systems employing Halbach arrays to create their magnetic fields is described. The system has several advantages over previously employed ones, especially in its simplicity and its freedom from being affected by weather conditions, accumulated dirt, or electrical interference from the LSM system itself.

Rotary encoding device

NASA Technical Reports Server (NTRS)

Leviton, Douglas B. (Inventor)

1993-01-01

A device for position encoding of a rotating shaft in which a polygonal mirror having a number of facets is mounted to the shaft and a light beam is directed towards the facets is presented. The facets of the polygonal mirror reflect the light beam such that a light spot is created on a linear array detector. An analog-to-digital converter is connected to the linear array detector for reading the position of the spot on the linear array detector. A microprocessor with memory is connected to the analog-to-digital converter to hold and manipulate the data provided by the analog-to-digital converter on the position of the spot and to compute the position of the shaft based upon the data from the analog-to-digital converter.

A permanent magnet tubular linear generator for wave energy conversion

NASA Astrophysics Data System (ADS)

Yu, Haitao; Liu, Chunyuan; Yuan, Bang; Hu, Minqiang; Huang, Lei; Zhou, Shigui

2012-04-01

A novel three-phase permanent magnet tubular linear generator (PMTLG) with Halbach array is proposed for the sea wave energy conversion. Non-linear axi-symmetrical finite element method (FEM) is implemented to calculate the magnetic fields along air-gap for different Halbach arrays of PMTLGs. The PMTLG characteristics are analyzed and the simulation results are validated by the experiment. An assistant tooth is implemented to greatly minimize the end and cogging effects which cause the oscillatory detent force.

Resolving phase ambiguities in the calibration of redundant interferometric arrays: implications for array design

DTIC Science & Technology

2015-11-30

matrix determinant. This definition is given in many linear algebra texts (see e.g. Bretscher (2001)). Definition 3.1 : Suppose we have an n-by-n...Processing, 2, 767 Blanchard P., Greenaway A., Anderton R., Appleby R., 1996, J. Opt. Soc. Am. A, 13, 1593 Bretscher O., 2001, Linear Algebra with...frequencies are not co- linear ) and one piston phase. This particular solution will then differ from the true solution by a phase ramp in the Fourier

Prototyping a new, high-temperature SQUID magnetometer system

NASA Astrophysics Data System (ADS)

Grappone, J. Michael; Shaw, John; Biggin, Andrew J.

2017-04-01

High-sensitivity Superconducting Quantum Inference Devices (SQUIDs) and μ-metal shielding have largely solved paleomagnetic noise problems. Combing the two allows successful measurements of previously unusable samples, generally sediments with very weak (<10 pAm2) magnetizations. The improved sensitivity increases the fidelity of magnetic field variation surveys, but surveys continue to be somewhat slow. SQUIDs have historically been expensive to buy and operate, but technological advances now allow them to operate at liquid nitrogen temperatures (77 K), drastically reducing their costs. Step-wise thermal paleomagnetics studies cause large lag times during later steps as a result of heating from and cooling to room temperature for measurements. If the cooling step is removed entirely, however, the lag time drops by at least half. Available magnetometers currently provide either SQUID-level (0.1 - 1 pAm2) sensitivity or continuous heating. Combining a SQUID magnetometer with a high temperature oven is the logical next step to uncover the mysteries of the paleofield. However, the few that currently offer high temperature capabilities with noise levels approaching 10 pAm2 require either spinning or vibrating the sample, necessitating additional handling and potentially causing damage to the sample. Two primary factors have plagued previous developments: noise levels and temperature gradients. Our entire system is shielded from the environment using 4 layers of μ-metal. Our sample oven (designed for 7 mm diameter samples) sits inside a copper pipe and operates at high-frequency AC voltages. High frequency (10 kHz) AC current reduces the skin depth of radio frequency (RF) electromagnetic noise, which allows the 2 mm-thick copper shielding to reduce RF noise by ˜94%, leaving a residual field of ˜1.5 nT at the SQUID's location, 14.9 mm from the oven. A computer-controlled Eurotherm 3216 thermal controller regulates the temperature within ± 0.5 ˚ C. To reach 700 ˚ C, just above the Curie temperature of Hematite, a temperature difference of nearly 900 ˚ C between the sample and the SQUID is required. Since dipole fields decay rapidly with distance (∝ r -3 ), the equipment is designed to handle temperature gradients above 500 ˚ C cm-1 for maximum sensitivity using a passive double-vacuum separation system. All the parts used are commercially available to help reduce the operating costs and increase versatility.

Extraction of breathing pattern using temperature sensor based on Arduino board

NASA Astrophysics Data System (ADS)

Patel, Rajesh; Sengottuvel, S.; Gireesan, K.; Janawadkar, M. P.; Radhakrishnan, T. S.

2015-06-01

Most of the basic functions of human body are assessed by measuring the different parameters from the body such as temperature, pulse activity and blood pressure etc. Respiration rate is the number of inhalations a person takes per minute and needs to be quantitatively assessed as it modulates other measurements such as SQUID based magnetocardiography (MCG) by bringing the chest closer to or away from the sensor array located inside a stationary liquid helium cryostat. The respiration rate is usually measured when a person is at rest and simply involves counting the number of inhalations for one minute. This paper aims at the development of a suitable methodology for the measurement of respiration rate with the help of a temperature sensor which monitors the very slight change in temperature near the nostril during inhalation & exhalation. The design and development of the proposed system is presented, along with typical experiment results.

[CII] At 1 < z < 2: Observing Star Formation in the Early Universe with Zeus (1 and 2)

NASA Technical Reports Server (NTRS)

Ferkinhoff, Carl; Hailey-Dunsheath, S.; Nikola, T.; Oberst, T.; Parshley, S.; Stacey, G.; Benford, D.; staguhn, J.

2010-01-01

We report the detection of the [CII] 158 micron fine structure line from six submillimeter galaxies with redshifts between 1.12 and 1.73. This more than doubles the total number of [CII] 158 micron detections reported from high redshift sources. These observations were made with the Redshift(z) and Early Universe Spectrometer(ZEUS) at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii between December 2006 and March 2009. ZEUS is a background limited submm echelle grating spectrometer (Hailey-Dunsheath 2009). Currently we are constructing ZEUS-2. This new instrument will utilize the same grating but will feature a two dimensional transition-edge sensed bolometer array with SQUID multiplexing readout system enabling simultaneous background limited observations in the 200, 340,450 and 650 micron telluric windows. ZEUS-2 will allow for long slit imaging spectroscopy in nearby galaxies and a [CII] survey from z 0.25 to 2.5.

Magnetic Property in Large Array Niobium Antidot Thin Films

NASA Astrophysics Data System (ADS)

Tinghui, Chen; Hsiang-Hsi, Kung; Wei-Li, Lee; Institute of Physics, Academia Sinica, Taipei, Taiwan Team

2014-03-01

In a superconducting ring, the total flux inside the ring is required to be an integer number of the flux quanta. Therefore, a supercurrent current can appear within the ring in order to satisfy this quantization rule, which gives rise to certain magnetic response. By using a special monolayer polymer/nanosphere hybrid we developed previously, we fabricated a series of superconducting niobium antidot thin films with different antidot diameters. The antidots form well-ordered triangular lattice with a lattice spacing about 200 nm and extend over an area larger than 1 cm2, which enables magnetic detections simply by a SQUID magnetometer. We observed magnetization oscillation with external magnetic field due to the supercurrent screening effect, where different features for large and small antidot thin films were found. Detailed size and temperature dependencies of the magnetization in niobium antidot nanostructures will be presented.

A new search for the permanent electric dipole moment of 129Xe at FRM-II

NASA Astrophysics Data System (ADS)

Sachdeva, N.; Chupp, T.; Degenkolb, S.; Fierlinger, P.; Kraegloh, E.; Kuchler, F.; Lins, T.; Meinel, J.; Niessen, B.; Stuiber, S.; Terrano, W. A.; Burghoff, M.; Fan, I.; Kilian, W.; Grüneberg, S.; Schnabel, A.; Seifert, F.; Stollfuss, D.; Trahms, L.; Voight, J.; Babcock, E.; Salhi, Z.; Huneau, J.; Singh, J.

2017-01-01

CP-violating sources in beyond-the-standard-model physics, necessary to explain baryon asymmetry, give rise to permanent electric dipole moments (EDMs). Precise EDM measurements of the neutron, electron, paramagnetic and diamagnetic atoms constrain CP-violating parameters. The previous limit for the 129Xe EDM is 6 ×10-27 e . cm (95 % CL). The HeXeEDM experiment at FRM-II (Munich Research Reactor) utilizes an ultralow magnetic field in a high-performance magnetically shielded room and 3He comagnetometer to improve the limit by up to three orders of magnitude. In the experiment, hyperpolarized 3He and 129Xe precession signals are detected with a SQUID magnetometer array in the presence of applied electric and magnetic fields. Recent progress will be presented. This work is supported US Department of Energy Grant No. DE FG02 04 ER41331.

Nanobridge SQUIDs as calorimetric inductive particle detectors

NASA Astrophysics Data System (ADS)

Gallop, John; Cox, David; Hao, Ling

2015-08-01

Superconducting transition edge sensors (TESs) have made dramatic progress since their invention some 65 years ago (Andrews et al 1949 Phys. Rev. 76 154-155 Irwin and Hilton 2005 Topics Appl. Phys. 99 63-149) until now there are major imaging arrays of TESs with as many as 7588 separate sensors. These are extensively used by astronomers for some ground-breaking observations (Hattori et al 2013 Nucl. Instrum. Methods Phys. Res. A 732 299-302). The great success of TES systems has tended to overshadow other superconducting sensor developments. However there are other types (Sobolewski et al 2003 IEEE Trans. Appl. Supercond. 13 1151-7 Hadfield 2009 Nat. Photonics 3 696-705) which are discussed in papers within this special edition of the journal. Here we describe a quite different type of detector, also applicable to single photon detection but possessing possible advantages (higher sensitivity, higher operating temperature) over the conventional TES, at least for single detectors.

Quantum optics in a high impedance environment

NASA Astrophysics Data System (ADS)

Puertas, Javier; Gheeraert, Nicolas; Krupko, Yuriy; Dassonneville, Remy; Planat, Luca; Foroughui, Farshad; Naud, Cecile; Guichard, Wiebke; Buisson, Olivier; Florens, Serge; Roch, Nicolas; Snyman, Izak

Understanding light matter interaction remains a key topic in fundamental physics. Its strength is imposed by the fine structure constant, α. For most atomic and molecular systems α =e2/ℏc 4 πɛo = 1 / 137 << 1 , giving weak interactions. When dealing with superconducting artificial atoms, α is either proportional to 1 /Zc (magnetic coupling) or Zc (electric coupling), where Zc is the characteristic impedance of the environment. Recent experiments followed the first approach, coupling a flux qubit to a low impedance environment, demonstrating strong interaction (α 1). In our work, we reached the large α regime, following a complementary approach: we couple electrically a transmon qubit to an array of 5000 SQUIDs. This metamaterial provides high characteristic impedance ( 3 kΩ), in-situ flux tunability and full control over its dispersion relation. In this new regime, all usual approximations break down and new phenomena such as frequency conversion at the single photon level are expected.

Nonlinear plasmonic behavior of nanohole arrays in thin gold films for imaging lipids

NASA Astrophysics Data System (ADS)

Subramaniyam, Nagarajan; Shah, Ali; Dreser, Christoph; Isomäki, Antti; Fleischer, Monika; Sopanen, Markku

2018-06-01

We demonstrate linear and nonlinear plasmonic behaviors of periodic nanohole arrays in thin gold (Au) films with varying periodicities. As expected, the linear optical transmission spectra of the nanohole arrays show a red-shift of the resonance wavelength and Wood's anomaly with increasing hole spacing. The optical transmission and electric near-field intensity distribution of the nanohole arrays are simulated using the finite element method. The nonlinear plasmonic behavior of the nanohole arrays is studied by using picosecond pulsed excitation at near-infrared wavelengths. The characteristic nonlinear signals indicating two-photon excited luminescence (TPEL), sum frequency generation, second harmonic generation, and four-wave mixing (FWM) are observed. A maximum FWM/TPEL signal intensity ratio is achieved for nanohole arrays with a periodicity of 500 nm. Furthermore, the significant FWM signal intensity and contrast compared to the background were harnessed to demonstrate the ability of surface-enhanced coherent anti-Stokes Raman scattering to visualize low concentrations of lipids deposited on the nanohole array with a periodicity of 500 nm.

A beamforming study for implementation of vibro-acoustography with a 1.75-D array transducer.

PubMed

Urban, Matthew W; Chalek, Carl; Haider, Bruno; Thomenius, Kai E; Fatemi, Mostafa; Alizad, Azra

2013-03-01

Vibro-acoustography (VA) is an ultrasound-based imaging modality that uses radiation force produced by two cofocused ultrasound beams separated by a small frequency difference, Δf, to vibrate tissue at Δf. An acoustic field is created by the object vibration and measured with a nearby hydrophone. This method has recently been implemented on a clinical ultrasound system using 1-D linear-array transducers. In this article, we discuss VA beamforming and image formation using a 1.75-D array transducer. A 1.75-D array transducer has several rows of elements in the elevation direction which can be controlled independently for focusing. The advantage of the 1.75-D array over a 1-D linear-array transducer is that multiple rows of elements can be used for improving elevation focus for imaging formation. Six configurations for subaperture design for the two ultrasound beams necessary for VA imaging were analyzed. The point-spread functions for these different configurations were evaluated using a numerical simulation model. Four of these configurations were then chosen for experimental evaluation with a needle hydrophone as well as for scanning two phantoms. Images were formed by scanning a urethane breast phantom and an ex vivo human prostate. VA imaging using a 1.75-D array transducer offers several advantages over scanning with a linear-array transducer, including improved image resolution and contrast resulting from better elevation focusing of the imaging point-spread function.

A Beamforming Study for Implementation of Vibro-acoustography with a 1.75D Array Transducer

PubMed Central

Urban, Matthew W.; Chalek, Carl; Haider, Bruno; Thomenius, Kai E.; Fatemi, Mostafa; Alizad, Azra

2013-01-01

Vibro-acoustography (VA) is an ultrasound-based imaging modality that uses radiation force produced by two cofocused ultrasound beams separated by a small frequency difference, Δf, to vibrate tissue at Δf. An acoustic field is created by the object vibration and measured with a nearby hydrophone. This method has recently been implemented on a clinical ultrasound system using one-dimensional (1D) linear array transducers. In this article, we discuss VA beamforming and image formation using a 1.75D array transducer. A 1.75D array transducer has several rows of elements in the elevation direction which can be controlled independently for focusing. The advantage of the 1.75D array over a 1D linear array transducer is that multiple rows of elements can be used for improving elevation focus for imaging formation. Six configurations for subaperture design for the two ultrasound beams necessary for VA imaging were analyzed. The point-spread functions for these different configurations were evaluated using a numerical simulation model. Four of these configurations were then chosen for experimental evaluation with a needle hydrophone as well as for scanning two phantoms. Images were formed by scanning a urethane breast phantom and an ex vivo human prostate. VA imaging using a 1.75D array transducer offers several advantages over scanning with a linear array transducer including improved image resolution and contrast due to better elevation focusing of the imaging point-spread function. PMID:23475919