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1

Age and growth of the neon flying squid, Ommastrephes bartrami, in the North Pacific ocean  

Microsoft Academic Search

Longitudinal sections of statoliths were observed by light microscopy on 237 individuals (158–510 mm mantle length, ML) of Ommastrephes bartrami, obtained from the North Pacific (26 °–46 °N, 143 °E–149 °W) during 1991–1994. The width of each increment sharply decreased from 5–7 ?m to about 1–2 ?m between the 80th and 100th increment, with a transition zone where increments were

Akihiko Yatsu; Satoshi Midorikawa; Takahiro Shimada; Yuji Uozumi

1997-01-01

2

A Comparative Study of Clam and Squid. Biting Flies of the Coastal Region. Diatoms: Nature's Aquatic Gems. Learning Experiences for Coastal and Oceanic Awareness Studies, Nos. 227, 231, 232. [Project COAST].  

ERIC Educational Resources Information Center

|Included are three units related to coastal and oceanic awareness. The units are: (1) A Comparative Study of Clam and Squid; (2) Biting Flies of the Coastal Region; and (3) Diatoms: Nature's Aquatic Gems. All three units were designed for secondary school students. Each unit contains teacher background materials, student activity materials,…

Delaware Univ., Newark. Coll. of Education.

3

Giant Squid  

NSDL National Science Digital Library

How do you get two dead Giant Squid the size of a school bus from a fishing boat in Spain to a museum in Washington, DC, USA? Call in the Navy! Find out how Operation Calamari unfolded and how the museum managed to put their new Giant Squid on display. Also included is a Learn More section that provides background information on the scientists recorded in the podcast, lessons, images, and cool facts.

2009-01-01

4

California Squid Fishery.  

National Technical Information Service (NTIS)

Squid usually migrate into shallow waters of 15 to 35 meters in depth to spawn, although some trawlers claim to have captured squid egg capsules at depths exceeding 100 meters. Spawning aggregations occur most frequently during winter in southern Californ...

1983-01-01

5

Optical fiber feedback SQUID magnetometer  

Microsoft Academic Search

This paper describes an optical fiber feedback superconducting quantum interference device (SQUID) magnetometer which was developed to improve electromagnetic interference characteristics. The SQUID consists of an RF SQUID probe, an RF amplifier, two multimode fibers, and a SQUID control unit. Phase-locked pulse width modulation (PWM) was used to construct a flux locked loop (FLL) circuit in the SQUID control unit.

S. Naito; Y. Sampei; T. Takahashi

1989-01-01

6

Science Nation: Glowing Squid  

NSDL National Science Digital Library

In deep ocean waters, it's sometimes difficult to hide from predators. That's why so many sea creatures have evolved extraordinary methods of disguise. Cephalopods, such as octopus, squid and cuttlefish, are big on camouflage, by day or night. In fact, the Hawaiian bobtail squid has several means of stealthy self- preservation. With support from the National Science Foundation (NSF), a team from the University of Wisconsin-Madison study one bobtail squid camouflage scheme; one that glows in the dark!

7

A digital SQUID controller  

NASA Astrophysics Data System (ADS)

We describe the performance of an improved DC SQUID controller base upon a PC data acquisition board with a single digital signal processor (DSP). The main DSP algorithm, which handles the flux-locked-loop, is optimally written in assembly language. To improve the performance of the controller, we have added a custom built frequency converter circuit that matches the modulation frequency of the DSP system to that of a commercial SQUID sensor and preamplifier. The noise level of the DC SQUID controller system is comparable with a commercial analog system, ~4??0/sqrt(Hz) at 100Hz. The current system could control up to 5 SQUID channels.

Limketkai, B.; Granger, J.; Weilert, M.; Hahn, Inseob

2003-05-01

8

Biomedical applications of SQUIDs  

SciTech Connect

SQUID magnetic field detectors are currently used in nearly a dozen laboratories in the United States and Europe to study biomagnetic fields produced by various organs of the human body. Some of the more promising findings of clinical and fundamental interest are briefly reviewed. Emphasis is placed on which technological improvements in the performance of SQUID systems may prove beneficial in future biomedical applications.

Williamson, S.J.; Brenner, D.; Kaufman, L.

1978-01-01

9

The Neon Alphabet Game  

Microsoft Academic Search

All previously identified components of trapped meteoritic neon—Ne-A, Ne-B, Ne- C, Ne-D, Ne-E, Ne-Al, Ne-A2, Ne-E(L), Ne-E(H), and Ne-O—and differences between the isotopic compositions of atmospheric, meteoritic, and solar-wind-implanted neon can be accounted for by mass fractionation and spallation reactions. These same two well-known processes can account for the experimental data that have previously been assigned to nucleogenetic anomalies in

D. D. Sabu; O. K. Manuel

1980-01-01

10

The neon sign  

NASA Astrophysics Data System (ADS)

What are a crumpled 55-gallon steel barrel and a tavern-style neon sign doing in the hallway of the physics building at a renowned and revered educational institution? It's attracting attention, stopping people in their tracks, and sending a message: physics is about size and color, motion and interaction; it's fun and it's interesting, something to experience for yourself.

Sampere, Samuel M.

1999-03-01

11

SQUIDs for everything  

NASA Astrophysics Data System (ADS)

John Clarke told Nature Materials about his work on superconducting quantum interference devices -- SQUIDs -- and his fascination with their applicability to many fields, from medicine to geophysics to quantum information and cosmology.

2011-04-01

12

SQUIDs quo vadis?  

NASA Astrophysics Data System (ADS)

For many decades R&D on superconducting quantum infererence devices (SQUIDs) has resulted in numerous and very diverse applications. However the commercial success of these applications is still marginal. This contribution analyses the reasons and discusses possible measures to improve this situation particularly for the application of multichannel SQUID systems for magnetoencephalography (MEG) and magnetocardiograpphy (MCG). The possible impact of combining low field magnetresonance imaging (lfMRI) with MEG and/or MCG is considered as well.

Koch, H.

2008-09-01

13

Future Medicine From Squid  

NSDL National Science Digital Library

This news article reports an exciting discovery about a toxic molecule found in both humans and in the Hawaiian bobtail squid that may hold the medical key for critical organ development and the immune system. Margaret McFall-Ngai, funded by the National Institute of Health, is studying the toxic molecule that causes tissue damage in human diseases such as whooping cough and gonorrhea and, is found to generate the light-producing organ in the Hawaiian bobtail squid.

Millot, Charmaine

2009-11-04

14

SQUID application research in Japan  

NASA Astrophysics Data System (ADS)

Japanese research activities using SQUIDs are reviewed in this paper. Low-Tc SQUIDs are applied to multi-channel systems for magnetoencephalogram (MEG) and magnetocardiogram (MCG). High-Tc SQUIDs are applied to MCG, nondestructive evaluation (NDE), SQUID microscopy, biological testing using fine magnetic markers, geological surveying, food inspection, large-scale integration (LSI) defect analysis and SQUID-NQR (nuclear quadrupole resonance). These applications of SQUIDs are being researched and developed actively and some of them are expected to be in the commercial market in the near future.

Itozaki, Hideo

2003-12-01

15

Biexcitons in solid neon  

Microsoft Academic Search

We study the creation of biexcitons in neon films on a metal substrate by one-photon processes. We demonstrate that photon-stimulated desorption of ions is a perfect tool for the investigation of these excitation processes, which possess very low cross sections. We show that the principle of the equivalent-core approximation which is well known from inner shell experiments can also be

P. Wiethoff; B. Kassühlke; D. Menzel; P. Feulner

2003-01-01

16

SQUID linear amplifier circuit simulations  

SciTech Connect

This paper presents numerical simulations of a single stage of a linear SQUID amplifier. The amplifier stage is fabricated in thin film technology, and consists of two asymmetric SQUIDs placed in the push-pull configuration. It was found that the Q of the tank circuit formed by SQUID inductance and a parasitic strip-line capacitance must be reduced to unity to avoid hysteretic operation. A load line analysis has determined the amplifier operating point and SQUID inductance which yield optimum linearity.

Gershenson, M.; Hastings, R.; Schneider, R.; Sorensen, E.; Sweeny, M.

1983-09-01

17

The Squid Squad  

NSDL National Science Digital Library

This site, hosted by the Northeast Fisheries Science Center (the regional research arm of the National Marine Fisheries Service) in collaboration with NMNH, serves as "a multimedia appendix to traditional scientific publications on squids, octopods and their relatives." The site contains color images (JPEG) and video clips (AVI) of squids and their relatives, as well as a keyword-searchable database of references on cephalopods. For information on systematics, follow the links to the Cephalopoda section of the Tree-of-Life project (of the University of Arizona).

18

Superconducting Quantum Interference Devices (SQUIDs)  

NSDL National Science Digital Library

Superconducting Quantum Interference Devices (SQUIDs) are sensitive probes that can detect small changes in the magnetic field. They take advantage of two important properties of superconductors, namely flux quantization and the Josephson effect. Furthermore, SQUIDs demonstrate quantum effects on the macroscopic scale, such as macroscopic wavefunctions, quantum interference and quantum mechanical tunneling. SQUID is a commercially available high temperature superconducting (HTS) DC SQUID magnetometer that will be used for our prototypical experiments. The objectives of this experiment are: 1. study the basic principles underlying SQUID applications, 2. observe zero resistance of superconductors and examine the superconducting phase transition, 3. observe the DC Josephson effect, 4. observe the periodically varying critical current in the resistive mode of the SQUID, 5. learn about the detection of extremely small magnetic fields by converting them into voltages and using a feedback loop, 6. measure the electrical characteristics of SQUID Josephson junctions and 7. build an ac/dc nano-voltmeter.

Khalid, Asma; Salman, Rabiya; Anwar, Muhammad S.

2012-02-13

19

Optical fiber feedback SQUID magnetometer  

SciTech Connect

This paper describes an optical fiber feedback superconducting quantum interference device (SQUID) magnetometer which was developed to improve electromagnetic interference characteristics. The SQUID consists of an RF SQUID probe, an RF amplifier, two multimode fibers, and a SQUID control unit. Phase-locked pulse width modulation (PWM) was used to construct a flux locked loop (FLL) circuit in the SQUID control unit. The operation of the optical fiber feedback SQUID is stable when a common mode voltage of ac 100 V/50 Hz is applied. It has an energy resolution of 1 x 10/sup -28/ J/Hz. This paper also describes the measurement of an auditory evoked field from the human brain in a magnetically shielded room using the fiber feedback SQUID with a gradiometer type pickup coil.

Naito, S.; Sampei, Y.; Takahashi, T. (Yokogawa Electric Corp., 2-9-32, Nakacho, Musashino-shi, Tokyo 180 (JP))

1989-04-01

20

Geophysical applications of squids  

SciTech Connect

Present and potential geophysical applications of Superconducting Quantum Interference Devices (SQUIDs) include remote reference magnetotellurics, controlledsource electromagnetic sounding, airborne gradiometry, gravity gradiometers, rock magnetism, paleomagnetism, piezomagnetism, tectonomagnetism, the location of hydrofractures for hot dry rock geothermal energy and enhanced oil and gas recovery, the detection of internal ocean waves, and underwater magnetotellurics.

Clarke, J.

1983-05-01

21

Geophysical applications of SQUIDS  

Microsoft Academic Search

Present and potential geophysical applications of Superconducting Quantum Interference Devices (SQUIDs) include remote reference magnetotellurics, controlledsource electromagnetic sounding, airborne gradiometry, gravity gradiometers, rock magnetism, paleomagnetism, piezomagnetism, tectonomagnetism, the location of hydrofractures for hot dry rock geothermal energy and enhanced oil and gas recovery, the detection of internal ocean waves, and underwater magnetotellurics.

J. Clarke

1983-01-01

22

The Microwave SQUID Multiplexer  

NASA Astrophysics Data System (ADS)

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.

Mates, John Arthur Benson

23

dc SQUID: Current noise  

Microsoft Academic Search

The computer model used by Tesche and Clarke to calculate the voltage noise across the dc SQUID is extended to calculate the circulating current noise around the SQUID loop, and the correlation between the circulating current noise and the voltage noise across the SQUID. The parameters chosen are % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4baFfea0dXde9vqpa0lb9% cq0dXdb9IqFHe9FjuP0-iq0dXdbba9pe0lb9hs0dXda91qaq-xfr-x% fj-hmeGabaqaciGacaGaaeqabaWaaeaaeaaakeaacqaHYoGycqGH9a% qpcaaIYaacbaGaa8htaiaa-LeadaWgaaWcbaacbiGaa4hmaaqabaGc% caGGVaacciGae0NPdy0aaSbaaSqaaiab9bcaGiab9bdaWaqabaGccq% GH9aqpcaaIXaGaaiilaiaabccacqqFtoWrcqqF9aqpcqqFYaGmcqaH% apaCcaWGRbWaaSbaaSqaaiaadkeaaeqaaOGaa8hvaiaa-9cacaWFjb% WaaSbaaSqaaiaa+bcacaGFWaaabeaakiab9z6agnaaBaaaleaacqqF%

Claudia D. Tesche; John Clarket

1979-01-01

24

Dc SQUID with variable thickness bridge  

NASA Astrophysics Data System (ADS)

We tried to fabricate dc SQUID with variable thickness bridge (VTB), instead of the tunnel junction type dc SQUIDs. Bridge was realized on a clean surface of substrate by double oblique depositions of Nb in a simple process. VTB type dc SQUIDs work well in our multichannel SQUID system. This work is partly supported by SUZUKI MEDICAL SCINECE RESEARCH FOUNDATION.

Furukawa, H.; Fujita, S.; Matani, A.; Yoshida, M.; Shirae, K.

1990-08-01

25

High Performance 16 MHz SQUID Feedback Electronics  

Microsoft Academic Search

We have constructed a dc SQUID feedback circuit operating at a modulation frequency of 16 ; MHz. Using a wideband superconducting thin film transformer to impedance match the SQUID to a high frequency amplifier allows the system to operate at the SQUID noise level for most types of low-Tc SQUIDs. This system has a closed loop bandwidth exceeding 3 ;

R. H. Koch; J. R. Rozen; P. Wöltgens; T. Picunko; W. J. Goss; D. K. Lathrop; R. Matthews

1996-01-01

26

[Magnetomyography with the SQUID].  

PubMed

The results of investigations of the neuromuscular system in man using a SQUID magnetometer with a second-order gradiometer detector are presented. After electrical stimulation of the tibial nerve in the hollow of the knee and the triggering of a monosynaptic proprioceptic reflex (Hoffmann-(H-)reflex), the biomagnetic field was recorded from the dorsal surface of the lower leg (soleus muscle of the m. triceps surae). The results obtained indicate that, over and beyond the data provided by electromyography, diagnostic information is provided on the state of the neuronal reflex pathways including muscle effector function. The biomagnetic field was evaluated in terms of latency, intensity, composition, characteristic behaviour and site of generation of the signal. In the geometry used, this noninvasive measuring technique can be employed for office observation of the spread of excitation through the muscle, as demonstrated by the response obtained following supramaximal stimulation of the supply nerve. PMID:8123767

Reincke, M

1993-11-01

27

RF SQUID Based Devices for MQC  

NASA Astrophysics Data System (ADS)

We present different types of integrated planar SQUID devices in view of Macroscopic Quantum Coherence (MQC) experiments. These devices include an rf SQUID as a probe to test the MQC, coupled to a readout system based on a dc SQUID sensor. Both dc SQUID and flux transformer are in a gradiometric configuration to minimize the electromagnetic noise from environment. We report data on dc SQUID performances as well as preliminary results on the decay from the metastable flux state for rf SQUID-based devices above the crossover temeperature (classical limit).

Longobardi, L.; Corato, V.; Granata, C.; Rombetto, S.; Russo, M.; Ruggiero, B.; Silvestrini, P.

28

High Performance 16 MHz SQUID Feedback Electronics.  

NASA Astrophysics Data System (ADS)

We have constructed a dc SQUID feedback circuit operating at a modulation frequency of 16 ; MHz. Using a wideband superconducting thin film transformer to impedance match the SQUID to a high frequency amplifier allows the system to operate at the SQUID noise level for most types of low-Tc SQUIDs. This system has a closed loop bandwidth exceeding 3 ; MHz and a slew rate of greater than 1 × 10 ^ 6 ? 0 /sec at frequencies upto 1 ; MHz . High-Tc SQUIDs have also been operated using a wirewound toroidal transformer with similar results. We will present a simple model of the maximum obtainable bandwidth and slew rate of a dc SQUID when operating in a feedback circuit. This system's bandwidth and slew rate as well as its very high dynamic range and low harmonic distortion allows SQUID magnetometers and gradiometers to be operated totally unshielded without unlocking in the dc, 60 Hz, and RFI electromagnetic fields typical of most SQUID applications.

Koch, R. H.; Rozen, J. R.; Wöltgens, P.; Picunko, T.; Goss, W. J.; Lathrop, D. K.; Matthews, R.

1996-03-01

29

Cyclic hydrocarbons: nanoscopic (?)-SQUIDs?  

NASA Astrophysics Data System (ADS)

A nonperturbative method for calculating persistent currents in molecules and nanoscopic quantum rings is presented. Starting from the extended Hubbard model on a ring threaded by an Aharonov-Bohm flux, a feedback term through which the current can generate magnetic flux is added. Another extension of the Hamiltonian describes the energy stored in the internally generated field. This model is evaluated using exact diagonalization and an iterative scheme to find the minima of the free energy with respect to the current. The magnetic properties due to electron delocalization of conjugated hydrocarbons like benzene [magnetic anisotropy, magnetic susceptibility exaltation, nucleus-independent chemical shift (NICS)] — that have become important criteria for aromaticity — can be examined using this model. A possible novel mechanism for a permanent orbital magnetic moment in quantum rings analogous to the one in ?-SQUIDs is found in the framework of the proposed model. The quantum rings must satisfy two conditions to exhibit this kind of permanent orbital magnetic moment: a negative Drude weight and an inductivity above the critical level.

Himmerich, M.; van Dongen, P. G. J.; Noack, R. M.

2006-05-01

30

Neon color spreading and structural information measures  

Microsoft Academic Search

This article presents a study on Van Tuijl’s (1975) neon effect. The neon effect can be described as an illusory spreading\\u000a of color around the colored elements of an otherwise black line pattern. The observer has a strong impression of colored light\\u000a projected onto a lattice of black lines. The hypothesis is advanced that the neon effect will only result

E. L. J. Leeuwenberg

1979-01-01

31

Rogue mantle helium and neon.  

PubMed

The canonical model of helium isotope geochemistry describes the lower mantle as undegassed, but this view conflicts with evidence of recycled material in the source of ocean island basalts. Because mantle helium is efficiently extracted by magmatic activity, it cannot remain in fertile mantle rocks for long periods of time. Here, I suggest that helium with high 3He/4He ratios, as well as neon rich in the solar component, diffused early in Earth's history from low-melting-point primordial material into residual refractory "reservoir" rocks, such as dunites. The difference in 3He/4He ratios of ocean-island and mid-ocean ridge basalts and the preservation of solar neon are ascribed to the reservoir rocks being stretched and tapped to different extents during melting. PMID:18202257

Albarède, Francis

2008-01-17

32

Theory of a UHF pumped double SQUID  

Microsoft Academic Search

A theoretical analytical analysis is presented which describes the behavior of a UHF pumped double SQUID (a traditional UHF SQUID in which a DC SQUID is used instead of the weak link) for the bias frequency ?B??c\\/[2(?+1\\/4)] max(?, 1), where ? is the hysteresis parameter, ?c is the cutoff frequency, and ? is the ratio of inductances of the UHF

B. Chesca

1996-01-01

33

Cryogenics for SQUIDS. Final report  

SciTech Connect

While not much work on SQUID cryocoolers as such has been done yet, a large amount of work on higher temperature refrigerators for infrared sensors and for use in spacecraft provides a sophisticated technical base upon which to build. A low-power five-stage Stirling cryocooler with a single-component SQUID gradiometer has begun operation. Although this machine requires only 20 W of mechanical power input to maintain a temperature of 7 K, a large reduction of input power is theoretically possible.

Zimmerman, J.E.

1980-01-01

34

SQUIDs: microscopes and nondestructive evaluation  

Microsoft Academic Search

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

Michael Mück

2005-01-01

35

Biomagnetic Measurements Using SQUID Instrumentation  

NASA Astrophysics Data System (ADS)

Biomagnetic measurements involve the detection of the magnetic fields generated by physiological activity in living organisms. Because magnetic fields are sensed remotely, no physical contact with the subject is required, making the technique totally non-invasive Furthermore, only the magnetic fields originating within the body are measured. No external field is applied and it can therefore be confidently stated that the technique is completely safe. These characteristics make biomagnetometry an ideal tool for the investigation of physiological processes. The only magnetic field detector capable of measuring these extremely weak biomagnetic signals is the Superconducting Quantum Interference Device (SQUID). In the last thirty years SQUID-based ultrasensitive magnetometers have been widely used in the investigation of physiologically produced magnetic fields for diagnostic purposes. Owing to the numerous sources of noise and interference typical of an urban environment, it has until recently been considered almost impossible to operate a SQUID magnetometer in such a location without magnetic shielding. We have overcome these technical problems and have successfully used our specially developed unshielded SQUID systems in laboratory and hospital environments. This instrumentation is suitable for recording the biomagnetic fields in adults, neonates and fetuses, and has been applied in a number of clinical studies including fetal magnetocardiography.

Rassi, D.; Zhuravlev, Y.

2000-09-01

36

Cold SQUIDs and hot samples  

SciTech Connect

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 magnetic 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.

Lee, T.S.C. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley national Lab., CA (United States). Materials Sciences Div.

1997-05-01

37

Development of a Squid Skinning and Eviscerating System.  

National Technical Information Service (NTIS)

A squid skinning and eviscerating machine was designed for California market squid, Loligo opalescens. Various operations such as orientation, cutting, skinning, and evisceration were completely automated. The pilot-scale machine cleaned squid at a rate o...

R. P. Singh D. E. Brown

1980-01-01

38

NEON Citizen Science: Planning and Prototyping  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) will be a national resource for ecological research and education. NEON citizen science projects are being designed to increase awareness and educate citizen scientists about the impacts of climate change, land-use change, and invasive species on continental-scale ecological processes as well as expand NEON data collection capacity by enabling laypersons to collect geographically distributed data. The citizen science area of the NEON web portal will enable citizen scientists to collect, contribute, interpret, and visualize scientific data, as well as access training modules, collection protocols and targeted learning experiences related to citizen science project topics. For NEON, citizen science projects are a means for interested people to interact with and contribute to NEON science. Investigations at vast spatial and temporal scales often require rapid acquisition of large amounts of data from a geographically distributed population of "human sensors." As a continental-scale ecological observatory, NEON is uniquely positioned to develop strategies to effectively integrate data collected by non-scientists into scientific databases. Ultimately, we plan to work collaboratively to transform the practice of science to include "citizens" or non-scientists in the process. Doing science is not limited to scientists, and breaking down the barriers between scientists and citizens will help people better understand the power of using science in their own decision making. In preparation for fully developing the NEON citizen science program, we are partnering with Project BudBurst (PBB), a citizen science project focused on monitoring plant phenology. The educational goals of PBB are to: (1) increase awareness of climate change, (2) educate citizen scientists about the impacts of climate change on plants and the environment, and (3) increase science literacy by engaging participants in the scientific process. Phenology was chosen as the focus of this citizen science campaign because it is a visible and comprehensible way of demonstrating the effects of climate change. In addition, plants are readily accessible in nearly every neighborhood and park, and wild area across the continent, so people can make observations whether they live near an inner city park or in the rural countryside. Recently, NEON developed data visualization tools for Project BudBurst to engage citizen science participants in "doing science" beyond data collection. By prototyping NEON citizen science through Project BudBurst, NEON is developing a better understanding of how to build a citizen science program that addresses areas of awareness, mastery, and leadership of scientific information like that which NEON will produce over the next 30 years.

Newman, S. J.; Henderson, S.; Gardiner, L. S.; Ward, D.; Gram, W.

2011-12-01

39

High sensitivity SQUID susceptibility measurements  

NASA Astrophysics Data System (ADS)

Scanning superconducting quantum interference device (SQUID) sensors have high sensitivity to magnetic flux ( 10-6?0/?Hz ) and magnetic moment (˜ 100 electron spins) under reasonable scanning conditions. In addition, a single turn field coil co-centered with the SQUID sensing loop provides excitation for simultaneous measurement of low field susceptibility, with sensitivity of ?˜10-6 at a spatial resolution of a few microns. I will present our recent measurements on several systems which exhibit weak susceptometry signals: thin film paramagnetic LaNiO3 that are (hopefully) the precursors to engineered superconducting films; individual magnetotactic bacteria, which are used as MRI contrast agents; and twinned high critical temperature cuprate and pnictide superconducting samples that may experience variations in the superfluid density at the twin boundary.

Kalisky, B.; Kirtley, J. R.; Qian, L. C.; Dwyer, B. L.; Moler, K. A.; Ngai, J.; Segal, Y.; Reiner, J.; Walker, F.; Ahn, C.; Hamilton, A. M.; Rutt, B.; Matin, A. C.; Auslaender, O. M.; Bonn, D. A.; Liang, R.; Hardy, W. N.; Analytis, J. G.; Chu, J.-H.; Fisher, I. R.

2011-03-01

40

Experimental Thermal Conductivity and Thermal Diffusivity Values for Neon and Mixtures of Neon and Nitrogen.  

National Technical Information Service (NTIS)

The authors report new measurements of thermal conductivity and thermal diffusivity, obtained with a transient hot-wire apparatus, for neon and two mixtures of neon with nitrogen. The measurements were made at temperatures between 58 K and 303 K (ITS 90) ...

R. A. Perkins H. M. Roder

1999-01-01

41

NEON Citizen Science: Planning and Prototyping (Invited)  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) will be a national resource for ecological research and education. NEON citizen science projects are being designed to increase awareness and educate citizen scientists about the impacts of climate change, land-use change, and invasive species on continental-scale ecological processes as well as expand NEON data collection capacity by enabling laypersons to collect geographically distributed data. The citizen science area of the NEON web portal will enable citizen scientists to collect, contribute, interpret, and visualize scientific data, as well as access training modules, collection protocols and targeted learning experiences related to citizen science project topics. For NEON, citizen science projects are a means for interested people to interact with and contribute to NEON science. Investigations at vast spatial and temporal scales often require rapid acquisition of large amounts of data from a geographically distributed population of “human sensors.” As a continental-scale ecological observatory, NEON is uniquely positioned to develop strategies to effectively integrate data collected by non-scientists into scientific databases. Ultimately, we plan to work collaboratively to transform the practice of science to include “citizens” or non-scientists in the process. Doing science is not limited to scientists, and breaking down the barriers between scientists and citizens will help people better understand the power of using science in their own decision making. In preparation for fully developing the NEON citizen science program, we are partnering with Project BudBurst (PBB), a citizen science project focused on monitoring plant phenology. The educational goals of PBB are to: (1) increase awareness of climate change, (2) educate citizen scientists about the impacts of climate change on plants and the environment, and (3) increase science literacy by engaging participants in the scientific process. Phenology was chosen as the focus of this citizen science campaign because it is a visible and comprehensible way of demonstrating the effects of climate change. In addition, plants are readily accessible in nearly every neighborhood and park, and wild areas across the continent, so people can make observations whether they live near an inner city park or in the rural countryside. Recently, NEON built 3 web tools that enable users to visualize PBB data. The tools include a mapping function that displays selected PBB distributional data on a map, an animated map that shows “green up” through time and space, and a graphing tool that compares number of species flowering or leafing out with day length. This prototyping will help NEON better understand how to engage citizen science participants in “doing science” beyond data collection.

Gram, W.

2010-12-01

42

Vortex fluctuation measurements in high-Tc SQUIDs  

Microsoft Academic Search

The correlation of the outputs of two dc-SQUIDs connected to the same solid washer was studied. A dedicated electronic system was used in order to operate both SQUIDs at the same time. It was found that the temporal correlation of the SQUID outputs is strongly dependent on the geometry of the SQUID loop. For a solid washer, the flux noise

S. Flament; M. Lam Chok Sing; W. Warsito; X. Ridereau; C. Gunther; L. Méchin; D. Bloyet; S. Abell

2004-01-01

43

21 CFR 868.1670 - Neon gas analyzer.  

Code of Federal Regulations, 2013 CFR

...Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1670 Neon gas analyzer. (a) Identification. A neon gas analyzer...

2013-04-01

44

Vapor pressure ratios over the solid neon isotopes  

Microsoft Academic Search

The first data for the neon-21 to neon-22 isotopic vapor pressure ratio are presented. New data of improved precision are presented for the neon-20 to neon-22 ratio. The use of the two sets of data narrows considerably the allowable temperature-dependent form of the free energy expansion in powers ofh2\\/2m required to describe the data. The effective Debye temperature determined in

G. T. McConville

1974-01-01

45

Vapor pressure ratios over the solid neon isotopes  

Microsoft Academic Search

The first data for the neon-21 to neon-22 isotopic vapor pressure ratio are presented. New data of improved precision are presented for the neon-20 to neon-22 ratio. The use of the two sets of data narrows considerably the allowable temperature-dependent form of the free energy expansion in powers of h 2\\/2 m required to describe the data. The effective Debye

G. T. McConville

1974-01-01

46

Computational Study of Emitted Spectra from the Neon Plasma Focus  

NASA Astrophysics Data System (ADS)

The expected emission spectra (full, Bremsstrahlung, recombination, and line) of neon focussed plasma have been studied for different conditions. Expected neon plasma spectra at certain electron temperature range have been plotted. The suitable electron temperatures ranges for neon plasma soft X-ray emission and extreme ultraviolet emission have been investigated. The X-ray ratio curves for various electron temperatures with probable electron and ion densities of the neon plasma produced have been computed with the assumption of non-local thermodynamic equilibrium model for the distribution of the ionic species. These ratio curves could be used for electron temperatures deduction of neon plasma focus.

Akel, M.; Alsheikh Salo, S.; Wong, C. S.

2013-08-01

47

Biochemical Properties of Squid Axon Membranes.  

National Technical Information Service (NTIS)

Biochemical and physiological studies in the giant axons of the Chilean squid Dosidicus Gigas were carried out in order to correlate metabolic dependent sodium transport and the enzymic profile of nerve membranes. Membrane fractions were isolated from the...

M. Canessa F. Vargas C. Hidalgo V. Riveros I. Zamudio

1966-01-01

48

Scanning microSQUID Force Microscope  

Microsoft Academic Search

A novel scanning probe technique is presented: Scanning microSQUID Force microscopy (SSFM). The instrument features independent topographic and magnetic imaging. The SSFM operates in a dilution refrigerator in cryogenic vacuum. Sample and probe can be cooled to 0.45 K. The probe consists of a microSQUID placed at the edge of a silicon chip attached to a quartz tuning fork. A

C. Veauvy; D. Mailly; K. Hasselbach

2001-01-01

49

A SQUID measurement system for immunoassays  

Microsoft Academic Search

A SQUID measurement system is presented that was developed for analysis of antigen–antibody reactions in fluid samples. The detection method is based on the signal generated by the remanent or relaxing magnetization of nanoparticles which are attached as labels to the antibodies. The measurement system involves two 7.2-mm-diameter multiloop SQUID chip magnetometers (type W7A) with a typical field noise of

H Matz; D Drung; S Hartwig; H Groß; R Kötitz; W Müller; A Vass; W Weitschies; L Trahms

1999-01-01

50

rf SQUID system for macroscopic quantum coherence experiments  

NASA Astrophysics Data System (ADS)

We present the design of an integrated planar SQUID device in view of macroscopic quantum coherence (MQC) experiments. This device is made up by an rf SQUID, as a probe to test the MQC, and a readout system based on a dc SQUID sensor coupled to the probe. To minimize the electromagnetic noise from environment, gradiometric configuration of rf SQUID, dc SQUID and a flux transformer is included. Preliminary results on the decay from the metastable flux state for different rf SQUID-based devices in the classical limit are shown.

Granata, C.; Corato, V.; Longobardi, L.; Russo, M.; Ruggiero, B.; Silvestrini, P.

2002-08-01

51

Neutron Resonance Parameters for Ne-21 (Neon)  

NASA Astrophysics Data System (ADS)

This document is part of the Supplement containing the complete sets of data of Volume 24 `Neutron Resonance Parameters' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Ne-21 (Neon).

Sukhoruchkin, S. I.; Soroko, Z. N.

52

Black Flies  

NSDL National Science Digital Library

Information about the common annoyance pest the Black Fly. The flies life cycle and control strategy are covered. While the information is specific to Los Angeles California, the same strategies are effective elsewhere. Personal protection information is also offered and is universally effective.

0002-11-30

53

The House Fly and Other Filth Flies  

NSDL National Science Digital Library

A primer on recognizing and controlling so-called "filth flies". Diptera commonly associated with trash, waste, and decay. The article covers common larger flies muscids, calliphorids, sarcophagids, as well as smaller fungus gnats, drain flies, and humpbacked flies (conspicuously missing are the soldier flies). Fly development, and biology are covered. No links, and no bibliography are offered.

0002-11-30

54

Low-noise SQUIDs with large transfer: two-stage SQUIDs based on DROSs  

NASA Astrophysics Data System (ADS)

We have realized a two-stage integrated superconducting quantum interference device (SQUID) system with a closed loop bandwidth of 2.5 MHz, operated in a direct voltage readout mode. The corresponding flux slew rate was 1.3×105 ?0/s and the measured white flux noise was 1.3 ??0/?Hz at 4.2 K. The system is based on a conventional dc SQUID with a double relaxation oscillation SQUID (DROS) as the second stage. Because of the large flux-to-voltage transfer, the sensitivity of the system is completely determined by the sensor SQUID and not by the DROS or the room-temperature preamplifier. Decreasing the Josephson junction area enables a further improvement of the sensitivity of the two-stage SQUID systems.

Podt, M.; Flokstra, J.; Rogalla, H.

2002-08-01

55

Scanning SQUID Microscope NDT System Based on Eddy Current Testing  

Microsoft Academic Search

A scanning SQUID microscope based on HTS dc SQUID has been developed. The SQUID is mounted inside the insulation vacuum of\\u000a a cryostat, which is separated from room temperature samples by a 65 ?m thick sapphire window. Operating with a double-D exciting\\u000a coil, it could be assembled to a scanning SQUID microscope Nondestructive Testing (NDT) system based on eddy current testing.

C. R. Zhong; Y. S. He; J. W. Liang; L. Ma; D. H. Lin

2010-01-01

56

Fly School  

NSDL National Science Digital Library

The processes used by humans to perform certain forms of learning are the same as those in many other species. Even the humble fruit fly is an excellent model of how genes affect our ability to learn.

2009-04-14

57

Hydrodynamics of locomotion in the squid Loligo pealei  

Microsoft Academic Search

Potential flow analysis, including unsteady eects, has been applied to live swimming squid, Loligo pealei. Squid were modelled as slender, axisymmetric bodies. High-speed video records, recorded at frame rates of 125 to 250 Hz, provided time-varying body outlines which were digitized automatically. Axisymmetric renderings of these body outlines and the real motion of the squid were used as the input

RIK J. A NDERSON; W ILLIE Q UINN; M. E DWIN DE MONT

2001-01-01

58

A SQUID NDE system for the investigation of pinch welds  

Microsoft Academic Search

HTS SQUID NDE systems attempt to achieve both high spatial resolution and high signal sensitivity, though often the more important parameter is determined by the sample of interest. SQUID microscopes offer micron-sized resolution by either bringing the sample into very close contact with a small SQUID sensor or by using a ‘‘flux guide’’ that is located in the tail of

C Carr; M A Espy; A V Urbaitis; R H Kraus Jr

2006-01-01

59

Diffusion of neon in white dwarf stars  

NASA Astrophysics Data System (ADS)

Sedimentation of the neutron rich isotope N22e may be an important source of gravitational energy during the cooling of white dwarf stars. This depends on the diffusion constant for N22e in strongly coupled plasma mixtures. We calculate self-diffusion constants Di from molecular dynamics simulations of carbon, oxygen, and neon mixtures. We find that Di in a mixture does not differ greatly from earlier one component plasma results. For strong coupling (coulomb parameter ?> few), Di has a modest dependence on the charge Zi of the ion species, Di?Zi-2/3 . However, Di depends more strongly on Zi for weak coupling (smaller ? ). We conclude that the self-diffusion constant DNe for N22e in carbon, oxygen, and neon plasma mixtures is accurately known so that uncertainties in DNe should be unimportant for simulations of white dwarf cooling.

Hughto, J.; Schneider, A. S.; Horowitz, C. J.; Berry, D. K.

2010-12-01

60

UHF high-T sub c SQUID  

SciTech Connect

This paper reports that for the first time, the authors have designed, constructed and investigated an UHF high-T{sub c} SQUID pumped at 360 MHz at 77 K. The SQUID is based on a one-hole interferometer with a microbridge Josephson contact made of bulk YBaCuO ceramics by the standard technique of mechanical scribing, followed by finishing with a high-voltage discharge electroerrosion. Magnetic flux sensitivity of the UHF SQUID as measured by the output signal of a quadratic detector with a dc amplifier of 40 kHz bandwidth was found to be about 5 {times} 10{sup {minus}5}{sub {phi}0}/Hz{sup 1/2} in the quasiwhite noise region (at a frequency over 700 Hz).

Shnyrkov, V.I.; Timofeev, V.P.; Khvostov, S.S.; Tsoi, G.M. (Inst. for Low Temperature Physics and Engineering, Ukr Academy of Sciences, 47 Lenin Ave., Kharkov 310164 (SU))

1991-08-20

61

Powering neon lamps through piezoelectric transformers  

Microsoft Academic Search

An investigation of the piezoelectric high-voltage ratio transformer as a potential component for powering neon lamps is discussed. The attractiveness of the piezoelectric technology is primarily the extreme simplicity of the resulting components, which are easy to reproduce in mass production, compared to the widely-used wire-wound ferrite transformers. Furthermore, on account of the electric network behaviour of a piezotransformer, the

P. J. M. Smidt; J. L. Duarte

1996-01-01

62

Nanofriction of neon films on superconducting lead.  

PubMed

With a quartz crystal microbalance technique we have studied the nanofriction of neon monolayers deposited on a lead surface at a temperature around 7 K. Unlike heavier adsorbates, Ne is found to systematically slide at such low temperatures without any evidence of pinning. The crossing of the Pb superconducting-metal transition is not accompanied by any change in dissipation, suggesting that the electronic contribution to friction is negligible for this system. PMID:20867468

Pierno, M; Bruschi, L; Fois, G; Mistura, G; Boragno, C; de Mongeot, F Buatier; Valbusa, U

2010-07-02

63

Small scale demand type neon liquefaction plant  

Microsoft Academic Search

Low-temperature measurement of the thermal conductivity of insulating materials is generally made using a boil-off calorimetry technique involving liquid hydrogen (LH2). Liquid neon (LNe) has nearly the same normal boiling point as LH2, but has a much larger heat of vaporization, allowing extended run times. The main drawback of using LNe has been its excessive cost; $170.00 versus $1.50\\/l for

W. P. Dube; A. J. Slifka; R. M. Bitsy; L. L. Sparks; K. B. Johnson

1990-01-01

64

Original superconducting quantum interference device (SQUID) design and measurement technique for flux noise source localization in SQUID systems  

Microsoft Academic Search

We present an original method for studying the low frequency flux noise due to vortices in superconducting quantum interference device (SQUID) systems. We use two SQUIDs connected to the same washer in order to study the correlation of their outputs. A dedicated electronic system has been built so as to operate both SQUIDs at the same time. It was thus

M. Lam Chok Sing; S. Flament; X. Ridereau; C. Gunther; L. Méchin; D. Bloyet

2003-01-01

65

Magnetism in SQUIDs at Millikelvin Temperatures  

NASA Astrophysics Data System (ADS)

We have characterized the temperature dependence of the flux threading dc SQUIDs cooled to millikelvin temperatures. The flux increases as 1/T as temperature is lowered; moreover, the flux change is proportional to the density of trapped vortices. The data are compatible with the thermal polarization of surface spins in the trapped fields of the vortices. In the absence of trapped flux, we observe evidence of spin-glass freezing at low temperature. These results suggest an explanation for the universal 1/f flux noise in SQUIDs and superconducting qubits.

Sendelbach, S.; Hover, D.; Kittel, A.; Mück, M.; Martinis, John M.; McDermott, R.

2008-06-01

66

Optimizing rearing conditions of hatchling loliginid squid  

Microsoft Academic Search

Eggs laid by the California market squid (Loligo opalescens) were collected from spawning grounds and reared in the laboratory. The eggs were maintained in a rearing tank that was part of a closed, recirculating system. The system included seven 220-l circular tanks with attached filtration. Five experiments were conducted to test hatchling survival. One of them evaluated survival on three

E. Vidal; F. DiMarco; J. Wormuth; P. Lee

2002-01-01

67

Whole cortex, 64 channel SQUID biomagnetometer system  

Microsoft Academic Search

The authors report on the development and testing of a novel, whole cortex, 64-channel superconducting quantum interference device (SQUID) biomagnetometer system operating in an unshielded environment. The essential features of this instrument, including the cryogenics system, the room-temperature digital electronics, and signal processing capabilities, are described. A noise cancellation scheme is incorporated which allows extraction of biomagnetic signals over the

J. Vrba; K. Betts; M. Burbank; T. Cheung; A. A. Fife; G. Haid; P. R. Kubik; S. Lee; J. McCubbin; J. McKay; D. McKenzie; P. Spear; B. Taylor; M. Tillotson; D. Cheyne; H. Weinberg

1993-01-01

68

High Resolution LTS-SQUID Microscopes  

NASA Astrophysics Data System (ADS)

We have developed a scanning superconducting quantum interference device (SQUID) microscope for imaging magnetic fields of room-temperature samples with sub-millimeter resolution. In our design, hand wound niobium pickup coils were coupled to commercially available low-temperature SQUID sensors. The SQUID sensor and the pickup coil are in the vacuum space of the cryostat separated typically less than 50?m by a thin sapphire window from the room-temperature sample. A computerized non-magnetic scanning stage with sub-micron resolution in combination with a tripod leveling system allows samples to be scanned within 10?m of the sapphire window. For a 20-turn 500?m diameter pickup coil, we achieved a field sensitivity of 350fT\\cdotHz-1/2 for frequencies above 1 Hz, and 1pT\\cdotHz-1/2 for a 10-turn 250mm coil. The SQUID microscope was used to image the distribution of time-dependent stimulus and action currents in anisotropic cardiac tissue, the remanent magnetization of the Martian meteorite ALH84001 during thermal demagnetisation, and the magnetic susceptibility of biogenic magnetite in the beak of homing pigeons.

Baudenbacher, Franz; Peters, Nicholas; Wikswo, John

2000-03-01

69

SQUID based remanence measurements for immunoassays  

Microsoft Academic Search

The use of fine magnetic particles as labels for antibodies and the measurement of their remanent magnetization for the preparation of immunoassays is presented. Antibodies were coupled with magnetic nanoparticles and samples were prepared by reaction of the magnetically labeled antibodies with their solid phase adsorbed antigen. After exposing the samples to a field of some mT a dc-SQUID system

R. Kotitz; H. Matz; L. Trahms; H. Koch; W. Weitschies; T. Rheinlander; W. Semmler; T. Bunte

1997-01-01

70

Nuclear Capture of Muons in Argon and Neon  

Microsoft Academic Search

The total nuclear capture rates of muons by argon and neon have been measured. The experiment was performed by stopping negative muons in a target of ultrapure gaseous deuterium (at 6 atm pressure and 293°K) separately contaminated by small amounts of argon and neon, and observing the differential time distribution of the decay electrons coming from muons stopped within the

A. Bertin; A. Vitale; A. Placci

1973-01-01

71

Dietary protein source and level alters growth in neon tetras.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nutritional studies for aquarium fish like the neon tetra are sparse in comparison with those for food fish. To determine the optimum dietary protein level and source for growth of neon tetras, diets were formulated to contain 25, 35, 45 and 55% dietary protein from either marine animal protein or ...

72

Primitive neon from the center of the Galápagos hotspot  

Microsoft Academic Search

We present new helium and neon measurements in dredged basaltic glasses from the Western Galápagos, with an emphasis on the submarine flanks of Fernandina volcano, but including the adjacent flanks of Darwin, Ecuador, Wolf, and Roca Redonda. The samples from the submarine flanks of Fernandina volcano have the least radiogenic helium and neon; 3He\\/4He ratios vary from 18 to 29

Mark D. Kurz; Joshua Curtice; Dan Fornari; Dennis Geist; Manuel Moreira

2009-01-01

73

Dietary Protein Source and Level Affects Growth in Neon Tetras  

Microsoft Academic Search

Nutritional studies for aquarium fishes like the neon tetra Paracheirodon innesi are sparse in comparison with those for food fish. To determine the optimum dietary protein level and source for growth of neon tetras, diets were formulated to contain 25, 35, 45, and 55% dietary protein from either marine animal protein or plant protein sources in a 4 × 2

Wendy M. Sealey; Frederic T. Barrows; Mike Casten; Ronald W. Hardy

2009-01-01

74

Boiling incipience and convective boiling of neon and nitrogen  

Microsoft Academic Search

Forced convection and subcooled boiling heat transfer data for liquid nitrogen and liquid neon were obtained in support of a design study for a 30 tesla cryomagnet cooled by forced convection of liquid neon. The cryogen data obtained over a range of system pressures, fluid flow rates, and applied heat fluxes were used to develop correlations for predicting boiling incipience

S. S. Papell; R. C. Hendricks

1977-01-01

75

Multiplexed HTS rf SQUID magnetometer array for eddy current testing of aircraft rivet joints  

Microsoft Academic Search

Using three rf SQUID magnetometers, a multiplexed SQUID array was implemented. The SQUIDs are positioned in line with 7 mm spacing and operated using one feedback electronics with sequential read out demodulation at different radio frequencies (rf). The cross-talk between SQUID channels was determined to be negligible. To show the performance of the SQUID array, eddy current (EC) measurements of

S. Gärtner; H.-J. Krause; N. Wolters; D. Lomparski; W. Wolf; J. Schubert; M. V. Kreutzbruck; K. Allweins

2002-01-01

76

Flying Fish  

Microsoft Academic Search

AN excellent opportunity of observing the aerial means of propulsion in the flying fish was afforded me during a six days' calm lately when crossing the Bay of Bengal. This must be my excuse for again touching this subject. I watched day by day some hundreds rise under the bows of the ship. The water surface was a glassy calm.

Alfred Carpenter

1885-01-01

77

Pop Fly  

NSDL National Science Digital Library

In this design challenge activity, learners invent a way to send a Ping-Pong ball flying high enough to catch it - like football with a twist! Learners use paint stirrers, a wooden spool, tape, and their feet to launch the ball. This fun hands-on activity introduces learners to the design process while exploring levers.

Wgbh

2010-01-01

78

Ionization of Metastable Neon by Electron Impact.  

NASA Astrophysics Data System (ADS)

Because of their energy and long lifetimes, metastable atoms participate in numerous reactions and play important roles in a wide variety of physical systems. While a large body of data is available for electron collisions involving ground state atoms, only a few experimental studies involving metastable atoms have been made. The limited scope of the data in due to the difficulty of producing a well characterized metastable source suitable for cross section measurements. The goal of this work was twofold. First, a metastable rare gas source that would allow cross section measurements to be made at impact energies above the ground state ionization threshold would be developed. Then the source would be used to study electron collision processes involving metastable rare gas atoms, beginning with electron impact ionization. The source developed in this work uses a high current - fast ion beam, periodic focusing, and near resonant charge exchange methods to produce a high density beam with a large metastable component. The ion source and lens train can achieve a maximum ion density of 9 times 10^8 ions per cc in the beam at an energy of 800eV. After charge exchanging with sodium vapor, the neutral density at the interaction region is 10^6 neon metastables per cc and 10^6 neon ground states per cc. Using the new source, electron impact ionization measurements of metastable neon were made from threshold to 200eV. The results are in excellent agreement with the general shape and magnitude of the preliminary 1973 experimental results of Dixon et al. and the Born half range calculations of Ton-That and Flannery (1977), the symmetric binary encounter calculations of Hyman (1979), and the scaled Born calculations of McGuire (1979).

Johnston, Martin Edward

79

Divertor Detachment During Neon Injection in TCV  

Microsoft Academic Search

Neon injection under feedback control has recently been performed for the first time in TCV. The target plasma is an ohmic, L-mode, SNL, open diverted equilibrium with I_p=280kA, q_95=3.5, kappa_95=1.6, a high poloidal depth and long connection lengths to the LFS strike zone. Results are reported for density scans (\\\\overlinen_e=2.5 arrow 6x10^19m-3) with two levels of Ne in the plasma.

R. A. Pitts; B. P. Duval; B. Joye; J. B. Lister; J.-M. Moret; A. Refke; J. Rommers; W. Van. Toledo; H. Weisen

1997-01-01

80

Fractionation of Terrestrial Neon by Hydrodynamic Hydrogen Escape from Ancient Steam Atmospheres (Abstract Only).  

National Technical Information Service (NTIS)

Atmospheric neon is isotopically heavier than mantle neon. By contrast, nonradiogenic mantle Ar, Kr, and Xe are not known to differ from the atmosphere. These observations are most easily explained by selective neon loss to space; however, neon is much to...

K. Zahnle

1991-01-01

81

Relaxation oscillation SQUIDs with high delta V/delta Phi  

NASA Astrophysics Data System (ADS)

Relaxation oscillation SQUIDs (ROSs) based on Nb/Al, AlO(x)/Al/Nb Josephson tunnel junctions have been designed and fabricated. The hysteretic SQUIDs have a maximum critical current of about 130 micro-A and an inductance of 20 pH. A voltage modulation of 400 micro-V and a flux to voltage transfer delta V/delta Phi of 4 mV/Phi(0) have been measured in these SQUIDs. Double relaxation oscillation SQUIDs (DROSs), which are based on two hysteretic SQUIDs, showed transfer coefficients up to 77 mV/Phi(0). The intrinsic white flux noise of the DROSs is smaller than 3-5 micro-Phi(0)/Hz. It is noted that the results are very promising for a next generation of SQUID systems with simplified read-out.

Adelerhof, D. J.; Nijstad, H.; Flokstra, J.; Rogalla, H.

1993-03-01

82

Damage accumulation in neon implanted silicon  

SciTech Connect

Damage accumulation in neon-implanted silicon with fluences ranging from 5x10{sup 14} to 5x10{sup 16} Ne cm{sup -2} has been studied in detail. As-implanted and annealed samples were investigated by Rutherford backscattering spectrometry under channeling conditions and by transmission electron microscopy in order to quantify and characterize the lattice damage. Wavelength dispersive spectrometry was used to obtain the relative neon content stored in the matrix. Implantation at room temperature leads to the amorphization of the silicon while a high density of nanosized bubbles is observed all along the ion distribution, forming a uniform and continuous layer for implantation temperatures higher than 250 deg.C. Clusters of interstitial defects are also present in the deeper part of the layer corresponding to the end of range of ions. After annealing, the samples implanted at temperatures below 250 deg.C present a polycrystalline structure with blisters at the surface while in the other samples coarsening of bubbles occurs and nanocavities are formed together with extended defects identified as (311) defects. The results are discussed in comparison to the case of helium-implanted silicon and in the light of radiation-enhanced diffusion.

Oliviero, E.; Peripolli, S.; Amaral, L.; Fichtner, P. F. P.; Beaufort, M. F.; Barbot, J. F.; Donnelly, S. E. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, Caixa Postal 15051, 91501-970 Porto Alegre, Rio Grande do Sul (Brazil); Departamento de Metalurgia, Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, Caixa Postal 15051, 90035-190 Porto Alegre, Rio Grande do Sul (Brazil); Laboratoire de Metallurgie Physique UMR6630, Universite de Poitiers, SP2MI, Boulevard Marie et Pierre Curie, BP30179, 86962 Futuroscope-Chasseneuil Cedex (France); Institute for Materials Research, University of Salford, Greater Manchester M5 4WT (United Kingdom)

2006-08-15

83

Quantum logic gates operation using SQUID qubits in bimodal cavity  

Microsoft Academic Search

We present a scheme to realize the basic two-qubit logic gates such as the quantum phase gate and SWAP gate using a detuned microwave cavity interacting with three-level superconducting-quantum-interference-device (SQUID) qubit(s), by placing SQUID(s) in a two-mode microwave cavity and using adiabatic passage methods. In this scheme, the two logical states of the qubit are represented by the two lowest

Ke-Hui Song

2006-01-01

84

The Renormalization Effects in the Microstrip-SQUID Amplifier  

NASA Astrophysics Data System (ADS)

The peculiarities of the microstrip-DC SQUID amplifier caused by the resonant structure of the input circuit are analyzed. It is shown that the mutual inductance, that couples the input circuit and the SQUID loop, depends on the frequency of electromagnetic field. The renormalization of the SQUID parameters due to the screening effect of the input circuit vanishes when the Josephson frequency is much greater than the signal frequency.

Berman, G. P.; Chumak, A. A.; Tsifrinovich, V. I.

2012-09-01

85

Investigation of noise sources in SQUID electronics  

SciTech Connect

The performance of SQUID-based electronics outside a laboratory-controlled environment may be degraded from that found in laboratory operation. Investigations on superconducting tubes, wires, and sheets have been conducted to identify contributions to such noise. Results have been obtained for bulk and thin film samples utilizing both the conventional low temperature materials, as well as the new high temperature oxide materials. Experiments have been conducted to quantify flux redistribution and flux motion in superconducting samples subjected to temperature changes, temperature gradients, and magnetic field gradients. These investigations have been conducted at magnetic fields typical of many SQUID applications, with field intensities much smaller than the critical values H/sub cl/. Penetration depth effects, flux pinning effects, and flux motion effects have been observed. The various types of experiments conducted along with specific results are described.

Clem, T.R.; Goldstein, M.J.; Purpura, J.W.; Allen, L.H.; Claassen, J.H.; Gubser, D.U.; Wolf, S.A.

1989-03-01

86

Biomagnetism using SQUIDs: status and perspectives  

NASA Astrophysics Data System (ADS)

Biomagnetism involves the measurement and analysis of very weak local magnetic fields of living organisms and various organs in humans. Such fields can be of physiological origin or due to magnetic impurities or markers. This paper reviews existing and prospective applications of biomagnetism in clinical research and medical diagnostics. Currently, such applications require sensitive magnetic SQUID sensors and amplifiers. The practicality of biomagnetic methods depends especially on techniques for suppressing the dominant environmental electromagnetic noise, and on suitable nearly real-time data processing and interpretation methods. Of the many biomagnetic methods and applications, only the functional studies of the human brain (magnetoencephalography) and liver susceptometry are in clinical use, while functional diagnostics of the human heart (magnetocardiography) approaches the threshold of clinical acceptance. Particularly promising for the future is the ongoing research into low-field magnetic resonance anatomical imaging using SQUIDs.

Sternickel, Karsten; Braginski, Alex I.

2006-03-01

87

Nanomagnet Characterization Using Scanning SQUID Microscopy  

NASA Astrophysics Data System (ADS)

Magnetic nanoparticles 5-50nm in size are of wide interest in the biological and medical fields. For instance, magnetotatic bacteria containing nanoscale mangnetite particles show potential for MRI contrast agents and targeting tumors. To date, characterization of nanomagnets has been done in large ensembles, where variations in shape and structure cannot be determined and interparticle coupling may cause bulk properties from those of isolated particles. We report our progress towards the detection and magnetic characterization of individual nanomagnets using a variable temperature scanning SQUID microscope (SSM). SSM is ideal for this challenge due to its high spin sensitivity, ˜100 ?B/sqrt(Hz). AC and DC modes of operation allow for direct probing of susceptibility, magnetic moment and switching times. Thermal separation between SQUID and sample allows temperature dependent studies of the transition between ferromagnetism and superparamagnetism. Results for both FePt nanomagnets and magnetosomes from magnetotactic bacteria will be shown.

Qian, Lisa; Kalisky, Beena; Kirtley, John; Kim, Jaemin; Benoit, Michael; Sun, Shouheng; Matin, A.; Moler, Kathryn

2010-03-01

88

Applications of high-temperature SQUIDs  

Microsoft Academic Search

Using examples from our recent work, we describe the progress toward three types of applications of SQUID magnetometers and gradiometers operating at the temperature of liquid nitrogen, and using high temperature superconductor (HTS) YBa2Cu3O7 thin-film sensors. First, we demonstrated usefulness of our magnetocardiographic data for diagnosis of cardiac arrhythmia and determination of risk of sudden cardiac death by means of

Y. Zhang; Y. Tavrin; H.-J. Krause; H. Bousack; A. I. Braginski; U. Kalberkamp; U. Matzander; M. Burghoff; L. Trahms

1995-01-01

89

A nanoscale SQUID operating at high magnetic fields  

SciTech Connect

A washer-free Nb nanoSQUID has been developed for measuring magnetization changes from nanoscale objects. The SQUID loop is etched into a 250 nm wide Au/Nb bilayer track and the diameter of the SQUID hole is {approx} 70 nm. In the presence of a magnetic field perpendicular to the plane of the SQUID, vortex penetration into the 250 nm wide track can be observed via the critical current-applied field characteristic and the value at which vortex first penetrates is consistent with the theoretical prediction. Upon removing the applied field, the penetrated vortices escape the track and the critical current at zero field is restored.

Lam, Simon K. H.; Clem, John R.; Yang, Wenrong

2011-10-13

90

Allometry indicates giant eyes of giant squid are not exceptional  

PubMed Central

Background 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. Results 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. Conclusions 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.

2013-01-01

91

The prospects of a subnanometer focused neon ion beam.  

PubMed

The success of the helium ion microscope has encouraged extensions of this technology to produce beams of other ion species. A review of the various candidate ion beams and their technical prospects suggest that a neon beam might be the most readily achieved. Such a neon beam would provide a sputtering yield that exceeds helium by an order of magnitude while still offering a theoretical probe size less than 1-nm. This article outlines the motivation for a neon gas field ion source, the expected performance through simulations, and provides an update of our experimental progress. PMID:21796647

Rahman, F H M; McVey, Shawn; Farkas, Louis; Notte, John A; Tan, Shida; Livengood, Richard H

2011-07-27

92

Stellar Neutron Capture on Neon Isotopes  

SciTech Connect

The stellar (n,{gamma}) cross sections of the Ne isotopes are important for a number of astrophysical quests, i.e., for the interpretation of abundance patterns in presolar material or with respect to the s-process neutron balance in red giant stars. This paper presents resonance studies of experimental data in the keV range, which had not been fully analyzed before. The analyses were carried out with the R-matrix code SAMMY including the consistent treatment of possible interferences in the resonant part. With these results the resonant part of the neon cross sections could be determined. If the component due to direct radiative capture is normalized at thermal neutron energies, one finds that the stellar rates had been grossly overestimated.

Heil, M.; Plag, R.; Juseviciute, A.; Kaeppeler, F. [Forschungszentrum Karlsruhe, Institut fuer Kernphysik, Postfach 3640, D-76021 Karlsruhe (Germany); Gallino, R. [Istituto di Fisica Generale, Universita di Torino, Via P. Giuria 1, I-10125 Turin (Italy); Sezione INFN di Torino, Via P. Giuria 1, I-10125 Turin (Italy); Mengoni, A. [CERN, CH-1211 Geneva 23 (Switzerland)

2005-05-24

93

8. DETAIL OF NORTHEAST ELEVATION SHOWING NEON TWA SIGN AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. DETAIL OF NORTHEAST ELEVATION SHOWING NEON TWA SIGN AND ROOF MASTS. LOOKING SOUTHWEST. - TWA Maintenance Hangar, South side of Tinicum Island Road, Philadelphia International Airport, Philadelphia, Philadelphia County, PA

94

Neon lineshift measurements in dense, laser-compressed plasmas  

Microsoft Academic Search

Measurement of shifts in the neon Lyman-alpha, -beta and -gamma lines and the He-like 1s2-1s2p line have been obtained in laser-compressed plasmas at n sub e at about 3 x 10 to the 22nd\\/cu cm and T sub e at about 300 eV. Calibration of the neon line wavelengths was determined relative to the emission lines of higher Z elements

K. G. H. Baldwin; J. R. Liu; J. D. Kilkenny; D. D. Burgess

1986-01-01

95

The primary component of upsilo Sagittarius is a neon star  

Microsoft Academic Search

From photographic and CCD spectra the abundance of neon and other elements in the atmosphere of the upsilo Sgr primary component has been derived. The values of Teff = 13500±150K and log g = 2.0±0.5 obtained earlier have been confirmed; the value of the turbulent velocity in the region of neon line formation, Vt(Ne) = 12 km\\/s, has been found;

V. V. Leushin

2000-01-01

96

The coefficient of self-diffusion of liquid neon  

Microsoft Academic Search

The coefficient of self-diffusion of liquid neon is measured by means of the capillary method within the temperature range of 25–43 K and in the pressure range of 10–100 atm. A natural neon-isotope mixture with 9.1%22Ne and a mixture enriched to 99%22Ne were available for the measurements. The measured runs show in the representation log D=f(1\\/T) and logD=f(p), respectively, straight

L. Beilogua; C. Gladun; B. Kubsch

1971-01-01

97

Acceleration of neon pellets to high speeds for fusion applications  

SciTech Connect

The injection of impurity pellets into the plasmas of tokamak fusion reactors has been proposed as a technique to lessen the deleterious effects of plasma disruptions. Equipment and techniques that were previously developed for pneumatic hydrogen pellet injection systems and used for plasma fueling applications were employed for a limited experimental study with neon pellets. Isotopic hydrogen pellets doped with neon have previously been used for injection into fusion plasmas to study impurity particle transport, and pure neon pellets are applicable for disruption studies. Using a repeating pneumatic injector in the laboratory, it was found that the formation and acceleration of 2.7-mm-diam neon pellets were relatively straightforward; reliable operation was demonstrated with both a single- and a two-stage light gas gun, including velocities of {approximately}700 m/s with a single-stage injector and up to 1740 m/s with a two-stage injector. Based on the operating sequences and successful tests demonstrated in the laboratory experiments, a three-barrel repeating pneumatic injector installed on the DIII-D tokamak was equipped with the necessary components for neon operation and has been used in initial disruption experiments with 1.8-mm-diam neon pellets. {copyright} {ital 1996 American Institute of Physics.}

Combs, S.K.; Love, T.L.; Jernigan, T.C.; Milora, S.L. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831-8071 (United States); Frattolillo, A.; Migliori, S. [ENEA, Centro Ricerche Energia Frascati, Frascati, Rome (Italy)

1996-03-01

98

Multichannel dc SQUID system with two stage configuration  

NASA Astrophysics Data System (ADS)

For experimental evaluation, two channel dc SQUID system of the parallel type has been constructed. We have confirmed the following performances; voltage bias operation can accept any dc SQUID with different critical current, crosstalk between channels is negligibly small, and noise reduction can achieve owing to the flux gain. This work is partly supported by SUZUKI MEDICAL SCIENCE RESEARCH FOUNDATION.

Furukawa, H.; Fujita, S.; Matani, A.; Yoshida, M.; Shirae, K.

1990-08-01

99

Fast Detection of Biological Targets With Magnetic Marker and SQUID  

Microsoft Academic Search

We have been developing a SQUID system for the detection of biological targets. In this system, magnetic markers are bound to the targets, and the magnetic signal from the bound markers is detected with the SQUID. In order to realize fast detection of the targets, we developed a liquid-phase detection method. First, we used large polymer beads as material to

Keiji Enpuku; H. Tokumitsu; Y. Sugimoto; H. Kuma; N. Hamasaki; A. Tsukamoto; T. Mizoguchi; A. Kandori; K. Yoshinaga; H. Kanzaki; N. Usuki

2009-01-01

100

Quantum analysis of a linear dc SQUID mechanical displacement detector  

Microsoft Academic Search

We provide a quantum analysis of a dc SQUID mechanical displacement detector within the subcritical Josephson current regime. A segment of the SQUID loop forms the mechanical resonator and motion of the latter is transduced inductively through changes in the flux threading the loop. Expressions are derived for the detector signal response and noise, which are used to evaluate the

M. P. Blencowe; E. Buks

2007-01-01

101

Decoherence and recoherence in a vibrating rf SQUID  

Microsoft Academic Search

We study an rf SQUID, in which a section of the loop is a freely suspended beam that is allowed to oscillate mechanically. The coupling between the rf SQUID and the mechanical resonator originates from the dependence of the total magnetic flux threading the loop on the displacement of the resonator. Motion of the latter affects the visibility of Rabi

Eyal Buks; M. P. Blencowe

2006-01-01

102

Reflectins: The Unusual Proteins of Squid Reflective Tissues  

Microsoft Academic Search

A family of unusual proteins is deposited in flat, structural platelets in reflective tissues of the squid Euprymna scolopes. These proteins, which we have named reflectins, are encoded by at least six genes in three subfamilies and have no reported homologs outside of squids. Reflectins possess five repeating domains, which are highly conserved among members of the family. The proteins

Wendy J. Crookes; Lin-Lin Ding; Qing Ling Huang; Jennifer R. Kimbell; Joseph Horwitz; Margaret J. McFall-Ngai

2004-01-01

103

High Temperature Superconductor (HTS) superconducting quantum interference device (SQUID) microscope  

NASA Astrophysics Data System (ADS)

The goal of this SBIR Phase 1 project is to establish the feasibility of designing a High Temperature Superconductor (HTS) Superconducting QUantum Interference Device (SQUID) microscope in order to detect defects, and verify customizations and repairs in MCM substrates. The overall goal of this SBIR program is to market an HTS SQUID microscope dedicated to the inspection of MCM substrates in a manufacturing environment.

1994-10-01

104

SQUID magnetometry from nanometer to centimeter length scales  

SciTech Connect

The development of Superconducting QUantum Interference Device (SQUID)-based magnetometer for two applications, in vivo prepolarized, ultra-low field MRI of humans and dispersive readout of SQUIDs for micro- and nano-scale magnetometery, are the focus of this thesis.

Hatridge, Michael J.

2010-06-28

105

Taonius megalops, a Squid that Rolls Up into a Ball  

Microsoft Academic Search

THERE are few recorded observations of living oceanic squids, but during a recent North Atlantic cruise, undamaged live branchiid squids were caught. In life, Taonius megalops are transparent except for deeply pigmented eyes, a silvery ink sac and chromatophores which are sparsely distributed over the mantle surface. In undisturbed specimens these chromatophores are contracted to tiny points, but when the

P. N. Dilly

1972-01-01

106

Archaeometric prospection with high-Tc SQUID gradiometers  

Microsoft Academic Search

Mapping of the Earth's magnetic field or its gradient is a widely used method in archaeological prospection. The use of SQUID's promises to be advantageous for archaeometry, since they combine a high field resolution with a large bandwidth. Compared to conventional Cs vapor sensors SQUIDs can be used for much faster magnetic mapping, allowing, for the first time, the investigation

A. Chwala; R. IJsselsteijn; T. May; N. Oukhanski; T. Schuler; V. Schultze; R. Stolz; H. G. Meyer

2003-01-01

107

High Tc SQUID system and magnetic marker for biological immunoassays  

Microsoft Academic Search

High Tc SQUID system is developed for the detection of the biological binding-reaction between antigen and its antibody. In this measurement, the antibody is labeled with magnetic nanoparticles, and the magnetic signal from the nanoparticles is measured. The excitation field of a few mT is applied in parallel to the SQUID in order to magnetize the nanoparticles. Due to mechanical

K. Enpuku; D. Kuroda; T. Q. Yang; K. Yoshinaga

2003-01-01

108

Read-out electronics for DC squid magnetic measurements  

DOEpatents

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.

Ganther, Jr., Kenneth R. (Olathe, KS); Snapp, Lowell D. (Independence, MO)

2002-01-01

109

A planar gradiometer based on a microwave rf-SQUID  

SciTech Connect

This paper describes a type of gradiometer, working on the basis of a planar microwave rf SQUID. In this type of rf-SQUID, a superconducting half-wavelength stripline resonator serves as tank circuit, into which the SQUID is integrated. If a gradiometer configuration is used for the SQUID (i.e. two loops), a certain asymmetry of the stripline resonator should be provided to ensure sufficient coupling between gradiometer and resonator. For first experiments, gradiometers were prepared from thin Niobium films on sapphire substrates, having either microbridges or tunnel junctions as Josephson elements. When operated in hysteretic mode, modulation voltages of about 100 {mu}V were measured for both microbridge- and tunnel junction SQUIDs.

Muck, M.; Diehl, D.; Heiden, C. (Institute of Thin Film and Ion Technology, Research Centre Julich GmbH, P.O. Box 1913, 5170 Julich (DE))

1991-03-01

110

Investigation of reproducibility of emission wavelength of helium-neon laser with external neon absorption cell (0.63 micrometers)  

Microsoft Academic Search

A stabilized LG-149-1 helium-neon laser with an external neon cell in a longitudinal magnetic field is investigated and found to provide wavelength reproducibility of 10 million, rather than the limiting values of 10 to the 8th power to 10 to the 9th power, due to shifts in the emission frequency. Frequency reproducibility is measured by a method utilizing a matrix

V. Y. Privalov; Y. G. Chulyayeva

1985-01-01

111

SQUID SAY IT WITH SKIN: A GRAPHIC MODEL FOR SKIN DISPLAYS IN CARIBBEAN REEF SQUID ( SEPIOTEUTHIS SEPIOIDEA )  

Microsoft Academic Search

ABSTRACT The aim of this paper is to describe the construction and use of a graphic model to express ‘squiddish’, visual skin displays in reef squid Sepioteuthis sepioidea. It was created and refined as a result of a field study off the Caribbean island, Bonaire, to systematize the repertoire of this species’ patterns for an ethogram. Squid communication is composed,of

R. A. Byrne; U. Griebel; J. B. Wood; J. A. Mather

112

MATING SYSTEMS AND SEXUAL SELECTION IN THE SQUID LOLIGO: HOW MIGHT COMMERCIAL FISHING ON SPAWNING SQUIDS AFFECT THEM?  

Microsoft Academic Search

The effect of targeted fishing on spawning grounds is central to the management of commercially valuable squids for at least three reasons: (1) the very short life cycle of about one year; (2) dense spawning aggrega- tions, which are easily targeted by fisheries; and (3) fish- ing techniques that could remove certain sexes or sizes of squids, thus leading to

ROGER T HANLON

1998-01-01

113

Acoustic detectability of squid egg beds  

NASA Astrophysics Data System (ADS)

Egg beds of the market squid (Loligo opalescens) on the bottom of Monterey Bay seem to have been detected by means of sidescan sonar at 420 kHz. Evidence for this is presented in the form of sidescan sonar images and egg-bed distribution maps from the same area, as prepared from camera surveys by scuba divers. The general detectability issue is also considered, with specific reference made to preliminary physical measurements performed on two egg capsules. [Work supported by Sea Grant.

Foote, Kenneth G.; Hanlon, Roger T.; Henry, Annette E.; Hochstaedter, Alfred; Kvitek, Rikk; Sullivan, Deidre; Yogozawa, Yuko

2003-10-01

114

Science Explorations: Investigate the Giant Squid  

NSDL National Science Digital Library

Science Explorations is a collaboration between AMNH and Scholastic designed to promote science literacy among students in grades 3 through 10. The Investigate the Giant Squid: Mysterious Cephalopod of the Sea exploration includes a documentary-style introduction, three online activities for students in grades 6-10, a glossary of related terms, a collection of articles, captioned photos, short videos, and informative links, off-line activities that challenge students to apply what they've learned, and advice and step-by-step tools to help students prepare research presentations.

115

HTS dc SQUIDs for eddy current NDE in an unshielded environment  

Microsoft Academic Search

The detection of flaws beside fasteners in aircraft structures is increasingly becoming an area where HTS SQUIDs can be successfully applied. Here, we present noise measurements of MgO bicrystal SQUIDs obtained in an unshielded environment and with the SQUIDs in motion. We describe eddy current NDE experiments using these SQUIDs to detect first and second layer flaws in simulated aircraft

C Carr; E. J Romans; J. C Macfarlane; C. M Pegrum; G. B Donaldson

1997-01-01

116

Linearized SQUID Array (LISA) for High Bandwidth Frequency-Domain Readout Multiplexing  

Microsoft Academic Search

We have designed and demonstrated a Superconducting Quantum Interference Device (SQUID) array linearized with cryogenic feedback. To achieve the necessary loop gain a 300 element series array SQUID is constructed from three monolithic 100-element series arrays. A feedback resistor completes the loop from the SQUID output to the input coil. The short feedback path of this Linearized SQUID Array (LISA)

T. M. Lanting; M. Dobbs; H. Spieler; A. T. Lee; Y. Yamamoto

2009-01-01

117

The curvy photonics of squid camouflage  

NASA Astrophysics Data System (ADS)

Cephalopods (squids and octopuses) ubiquitously possess reflective structures in their skin composed of ``reflectin'' proteins. Although a few simple laminar, Bragg-stack type optical structures have been known in a handful of common squid species for some time, our extensive survey of optically active tissues of exotic deep-sea species has revealed complex, extended curvatures and topologies in dermal reflectors of these rarely-studied animals. Molecular deep-sequencing has revealed these structures also to be composed of reflectin-like proteins. Here we show a survey of some of these deep-sea reflector structures, and present evidence that each novel structure may be a transform of the radiance in the optical niche in the ocean where each of these species live, such that light reflecting off the sides of these animals in their specific ocean habitat resembles the light that would be transmitted through the animals if they were transparent, from many different viewing angles and possible ocean depths.

Sweeney, Alison; Holt, Amanda; Daniel, Morse; Stramski, Dariusz

2013-03-01

118

Base distance optimization for SQUID gradiometers  

SciTech Connect

The measurement of magnetic fields generated by weak nearby biomagnetic sources is affected by ambient noise generated by distant sources both internal and external to the subject under study. External ambient noise results from sources with numerous origins, many of which are unpredictable in nature. Internal noise sources are biomagnetic in nature and result from muscle activity (such as the heart, eye blinks, respiration, etc.), pulsation associated with blood flow, surgical implants, etc. Any magnetic noise will interfere with measurements of magnetic sources of interest, such as magnetoencephalography (MEG), in various ways. One of the most effective methods of reducing the magnetic noise measured by the SQUID sensor is to use properly designed superconducting gradiometers. Here, the authors optimized the baseline length of SQUID-based symmetric axial gradiometers using computer simulation. The signal-to-noise ratio (SNR) was used as the optimization criteria. They found that in most cases the optimal baseline is not equal to the depth of the primary source, rather it has a more complex dependence on the gradiometer balance and the ambient magnetic noise. They studied both first and second order gradiometers in simulated shielded environments and only second order gradiometers in a simulated unshielded environment. The noise source was simulated as a distant dipolar source for the shielded cases. They present optimal gradiometer baseline lengths for the various simulated situations below.

Garachtchenko, A. [Applied Materials, Santa Clara, CA (United States); Matlashov, A.; Kraus, R. [Los Alamos National Lab., NM (United States)

1998-12-31

119

Interchannel interactions in high-energetic radiationless transitions of neon-like ions.  

National Technical Information Service (NTIS)

Relativistic K-LL Auger transition rates in intermediate coupling including interchannel interactions are presented for nine ions in the neon-isoelectronic sequence up to uranium. For neutral neon a comparison with experimental data is given. We demonstra...

S. Fritzsche G. Zschornack G. Musiol G. Soff

1990-01-01

120

Equation of state of solid neon from x-ray diffraction measurements to 110 GPa  

SciTech Connect

This paper briefly discusses the pressure-volume properties of condensed neon. X-ray diffraction techniques are used to determine solid neon equation of state and crystal structure. 16 refs., 2 figs. (LSP)

Hemley, R.J.; Jephcoat, A.P.; Zha, C.S.; Mao, H.K.; Finger, L.W.; Cox, D.E.

1987-01-01

121

Multistage Zeeman deceleration of metastable neon  

SciTech Connect

A supersonic beam of metastable neon atoms has been decelerated by exploiting the interaction between the magnetic moment of the atoms and time-dependent inhomogeneous magnetic fields in a multistage Zeeman decelerator. Using 91 deceleration solenoids, the atoms were decelerated from an initial velocity of 580 m/s to final velocities as low as 105 m/s, corresponding to a removal of more than 95% of their initial kinetic energy. The phase-space distribution of the cold, decelerated atoms was characterized by time-of-flight and imaging measurements, from which a temperature of 10 mK was obtained in the moving frame of the decelerated sample. In combination with particle-trajectory simulations, these measurements allowed the phase-space acceptance of the decelerator to be quantified. The degree of isotope separation that can be achieved by multistage Zeeman deceleration was also studied by performing experiments with pulse sequences generated for {sup 20}Ne and {sup 22}Ne.

Wiederkehr, Alex W.; Motsch, Michael; Hogan, Stephen D.; Andrist, Markus; Schmutz, Hansjuerg; Lambillotte, Bruno; Agner, Josef A.; Merkt, Frederic [Laboratorium fuer Physikalische Chemie, ETH Zuerich, CH-8093 Zuerich (Switzerland)

2011-12-07

122

Electron Impact Excitation and Ionization of Neon  

NASA Astrophysics Data System (ADS)

We have further developed the B-Spline R-matrix (BSR) code [1] to allow for a large number of pseudo-states in the close-coupling expansion. In the present work, the BSRMPS approach [2] was employed to perform semi-relativistic (Breit-Pauli) close-coupling calculations for elastic scattering, excitation, and ionization of neon from both the ground state and the metastable excited states. Coupling to the ionization continuum through the pseudo-states is important for low-energy elastic scattering (to represent polarizability effects), for excitation in the ``intermediate'' energy regime of about 1-5 times the ionization potential, and to allow for the calculation of ionization processes by transforming the results obtained for excitation of the positive-energy pseudo-states. The current results represent a significant extension of our earlier near-threshold work [3] and previous non-relativistic RMPS calculations [4,5].[4pt] [1] O. Zatsarinny, Comp. Phys. Commun. 174 (2006) 273.[0pt] [2] O. Zatsarinny and K. Bartschat, Phys. Rev. Lett. 107 (2011) 023203.[0pt] [3] O. Zatsarinny and K. Bartschat, J. Phys. B 37 (2004) 2173.[0pt] [4] C. P. Ballance and D. C. Griffin, J. Phys. B 37 (2004) 2943.[0pt] [5] C. P. Ballance et al., J. Phys. B 37 (2004) 4779.

Zatsarinny, Oleg; Bartschat, Klaus

2012-10-01

123

Electron injection into dense neon: A comparison with hydrogen and helium  

Microsoft Academic Search

As a probe of the electron-neon fluid surface barrier, hot electrons (~1 eV) obtained from thin-film cold-cathode emitters were injected into neon liquid and dense neon gas at temperatures below 77 K. In neon, at all densities including the liquid, we find a universal characteristic shape for the current attenuationi\\/i0 vs. E\\/N, in contrast to the cases of helium and

Wayne D. Johnson; James R. Broomall; David G. Onn

1979-01-01

124

Development of airborne remote sensing instrumentations for NEON  

NASA Astrophysics Data System (ADS)

Airborne remote sensing plays a critical role in the scaling strategy underpinning the National Ecological Observatory Network (NEON) design. Airborne spectroscopy and waveform LiDAR will quantify plant species type and function, and vegetation structure and heterogeneity at the scale of individual shrubs and larger plants (1-3 meters) over hundreds of square kilometers. Panchromatic photography at better than 30 cm resolution will retrieve fine-scale information regarding land use, roads, impervious surfaces, and built structures. NEON will build three airborne systems to allow for routine coverage of NEON sites (60 sites nationally) and the capacity to respond to investigator requests for specific projects. The system design achieves a balance between performance, and development cost and risk. The approach takes full advantage of existing commercial airborne LiDAR and camera components. However, requirements for the spectrometer represent a significant advancement in technology. A pushbroom imaging spectrometer design is being proposed to simultaneously achieve high spatial, spectral and signal-to-noise ratio and a high degree of uniformity in response across wavelength and a wide field of view. To reduce risk during NEON construction, a spectrometer design verification unit is under development by the Jet Propulsion Laboratory to demonstrate that the design and component technologies meet operational and performance requirements. This paper presents an overview of system design, key requirements and development status of the NEON airborne instrumentation.

Johnson, Brian R.; Kampe, Thomas U.; Kuester, Michele

2010-08-01

125

Neon color spreading in dynamic displays: Temporal factors.  

PubMed

When a red star is placed in the middle of an Ehrenstein figure so as to be collinear with the surrounding black rays, a reddish veil is perceived to fill the white center. This is called neon color spreading. To better understand the processes that give rise to this phenomenon, we studied the temporal properties of the effect. Specifically, we presented a "sustained" black Ehrenstein figure (rays) for 600 ms and a "transient" red star for 48 ms, or the converse pattern, at various stimulus onset asynchronies (-100-700 ms) and asked subjects to compare the strength of the neon color in the test stimulus to that of a reference pattern in which the transient star had an onset asynchrony of 300 ms. Additional exposure durations of 24 and 96 ms were used for each transient stimulus in order to study the effect of temporal integration. Simultaneity of the on- and off-transients of the star and the Ehrenstein rays were found to optimize neon color spreading, especially when both stimuli terminated together. Longer exposure durations of the transient stimulus up to 96 ms further improved the effect. Neon color spreading was much reduced when the transient stimulus was presented soon after the beginning of the sustained stimulus, with a gradual build-up towards the end. These results emphasize the importance of stimulus onset asynchrony (SOA) and stimulus termination asynchrony (STA) for the perception of neon color spreading. PMID:24097045

Cicchini, Marco; Spillmann, Lothar

2013-10-04

126

NEON INSIGHTS FROM OLD SOLAR X-RAYS: A PLASMA TEMPERATURE DEPENDENCE OF THE CORONAL NEON CONTENT  

SciTech Connect

An analysis using modern atomic data of fluxes culled from the literature for O VIII and Ne IX lines observed in solar active regions by the P78 and Solar Maximum Mission satellites confirms that the coronal Ne/O abundance ratio varies by a factor of two or more, and finds an increase in Ne/O with increasing active region plasma temperature. The latter is reminiscent of evidence for increasing Ne/O with stellar activity in low-activity coronae that reaches a 'neon saturation' in moderately active stars at approximately twice the historically accepted solar value of about 0.15 by number. We argue that neon saturation represents the underlying stellar photospheric compositions, and that low-activity coronae, including that of the Sun, are generally depleted in neon. The implication would be that the solar Ne/O abundance ratio should be revised upward by a factor of about two to n(Ne)/n(O) {approx} 0.3. Diverse observations of neon in the local cosmos provide some support for such a revision. Neon would still be of some relevance for reconciling helioseismology with solar models computed using recently advocated chemical mixtures with lower metal content.

Drake, Jeremy J., E-mail: jdrake@cfa.harvard.edu [Smithsonian Astrophysical Observatory, MS-3, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-12-10

127

Development of new HTS-SQUID and HTS current sensor for HTS-SQUID beam current monitor  

NASA Astrophysics Data System (ADS)

Two years ago, a prototype of a highly sensitive beam current monitor with a high-temperature superconducting (HTS) SQUID, an HTS current sensor and an HTS magnetic shield, that is, an HTS-SQUID monitor, was installed in the beam transport line of the RIKEN ring cyclotron (RRC). As a result, the beam intensity of a sub-?A beam was successfully measured by the prototype HTS-SQUID monitor. In fact, the intensity of a sub-?A 40Ar15+ (63 MeV/u) beam was successfully measured with a 500 nA resolution. However, the current resolution of the prototype HTS-SQUID monitor is not sufficient to measure the current of a uranium beam, which is accelerated in a new radioactive isotope (RI) beam facility called "RI Beam Factory" (RIBF). A minimum current resolution of 1 nA is required for the measurement of the uranium beam. Therefore, we are developing a new HTS-SQUID monitor so as to improve the current resolution. This new monitor consists of three parts, the HTS SQUID, an HTS current sensor and an HTS magnetic shield, and these parts have been separately developed this year. The high-permeability core that is installed in the two input coils of the HTS-SQUID is an extremely important part in this new HTS-SQUID monitor. A 50-fold improvement in gain was successfully realized using the high-permeability core compared with that obtained without the high-permeability core. Another key factor is the substrate of the HTS current sensor. A MgO ceramic tube was used for the substrate of the HTS current sensor in the prototype HTS-SQUID monitor. However, it was difficult to form the bridge circuit using the MgO ceramic substrate in the new HTS-SQUID monitor, because the bridge circuit that magnetically connects the HTS current sensor and the HTS-SQUID has to be three-dimensional. To solve this problem, silver (Ag) of 99.9% purity was adopted for the substrates of the HTS current sensor in the new HTS-SQUID monitor. Then the surfaces of the substrates were coated by a thin layer (70?m) of Bi2-Sr2-Ca1-Cu2-Ox (Bi 2212), which is an HTS material. We report the results of this development.

Watanabe, T.; Sasaki, Y.; Kase, M.; Watanabe, S.; Ikeda, T.; Kawaguchi, T.; Yano, Y.

2008-02-01

128

Purification and Liquefacttion of Neon Using a Helium Refrigeration Cycle  

NASA Astrophysics Data System (ADS)

The cryogenic plant developed by Linde Kryotechnik is used to extract neon out of a crude gas flow coming from an air separation plant. The crude gas is cooled down by a two stage helium refrigeration process using the Linde Kryotechnik dynamic gas bearing turbines. After the first cooling stage, nitrogen is liquefied and separated from the crude gas. The Cryogenic adsorbers located at a temperature level below 80 K clean the crude gas from remaining nitrogen traces before the neon-helium mixture enters the final cooling stage. In the second cooling stage neon is liquefied and separated from the helium. The final product quality will be achieved within a rectification column at low pressure level.

Boeck, S.

2010-04-01

129

Ionization waves in the medium pressure helium and neon plasma.  

NASA Astrophysics Data System (ADS)

We present the experimental results obtained on the ionisation waves in the helium and neon plasmas, within the pressure range of 200 Pa to 2000 Pa (133 Pa = 1 Torr), and for discharge electric currents of 5 mA to 35 mA. The main characteristics of the ionization waves in the medium presure neon and helium discharge are a small amplitude and a high frequency. The amplitude of the waves is smaller than 1 V. In the case of the neon plasma, the frequency varies between approximately 700 Hz and 2250 Hz and increases with the discharge current. In the helium plasma, the frequency is in the range between approximately 1500 Hz and 4000 Hz and decreases with the discharge electric current.

Barna, Emil; Covlea, Vania; Biloiu, Costel; Bazavan, Marian; Mihai Ticos, Catalin

130

Helium and neon isotopes in deep Pacific Ocean sediments  

SciTech Connect

Helium and neon concentration measurements, along with isotope ratio determinations, have been made for particles collected in the deep Pacific with a magnetic sled, and they are believed to be of extraterrestrial origin. Analyses were made for samples consisting of composites of many extremely fine particles and for several individual particles large enough to contain sufficient gas for analysis but small enough to escape melting in their passage through the atmosphere. Step-heating was employed to extract the gas. Cosmic-ray spallation products or solar-wind helium and neon, if present, were not abundant enough to account for the isotopic compositions measured. In the case of the samples of magnetic fines, the low temperature extractions provided elemental and isotopic ratios in the general range found for the primordial gas in carbonaceous chondrites and gas-rich meteorites. The isotopic ratios found in the high temperature extractions suggest the presence of solar-flare helium and neon.

Nier, A.O.; Schlutter, D.J. (Univ. of Minnesota, Minneapolis (USA)); Brownlee, D.E. (Univ. of Washington, Seattle (USA))

1990-01-01

131

Münchhausen effect: tunneling in an asymmetric SQUID  

NASA Astrophysics Data System (ADS)

A classical system cannot escape out of a metastable state at zero temperature. However, a composite system made from both classical and quantum degrees of freedom may drag itself out of the metastable state by a sequential process. The sequence starts with the tunneling of the quantum component which then triggers a distortion of the trapping potential holding the classical part. Provided this distortion is large enough to turn the metastable state into an unstable one, the classical component can escape. This process reminds of the famous baron Münchhausen who told the story of rescuing himself from sinking in a swamp by pulling himself up by his own hair-we thus term this decay the `Münchhausen effect'. We show that such a composite system can be conveniently studied and implemented in a dc-SQUID featuring asymmetric dynamical parameters. We determine the dynamical phase diagram of this system for various choices of junction parameters and system preparations.

Thomann, A. U.; Geshkenbein, V. B.; Blatter, G.

2009-05-01

132

Development of SQUID VCM magnetic measurement system for pressure experiment  

NASA Astrophysics Data System (ADS)

Superconducting quantum interference device (SQUID) is a powerful tool, which can detect small magnetic signal with high sensitivity, but it is not easy to make use of the SQUID. Especially in the case of the pressure experiment, it is more difficult to utilize the SQUID due to the space limitation of the coil arrangement. We are trying to establish the vibrating coil magnetometer (VCM) using the SQUID, and our attempt started from the imitating of Ishizuka type of VCM. In the development process, we have developed the original method of coil vibration control and real-time phase-detection system. As the performance test, the superconducting transition of lead was observed in some conditions, and the present sensitivity was confirmed to be about 10-8 emu at earth field.

Yamada, J.; Irie, K.; Mito, M.; Deguchi, H.; Takagi, S.

2007-03-01

133

Application of a dc SQUID to rf amplification: NQR  

SciTech Connect

Superconducting QUantum Interference Devices (SQUIDs) have been used for more than a decade for the detection of magnetic resonance. Until recently, these devices had mostly been confined to operation in the audiofrequency range, so that experiments have been restricted to measurements of resonance at low frequencies, or of changes in the static susceptibility of a sample induced by rf irradiation at the resonant frequency. However, the recent extension of the operating range of low noise dc SQUIDs to radiofrequencies (rf) allows one to detect magnetic resonance directly at frequencies up to several hundred megahertz. In this paper, we begin by summarizing the properties of dc SQUIDs as tuned rf amplifers. We then describe first, the development of a SQUID system for the detection of pulsed nuclear quadrupole resonance (NQR) at about 30 MHz and second, a novel technique for observing magnetic resonances in the absence of any externally applied rf fields.

Hilbert, C.; Clarke, J.; Sleator, T.; Hahn, E.L.

1985-05-01

134

Cascade units for neon isotope production by rectification  

NASA Astrophysics Data System (ADS)

The basics of neon isotope separation by the distillation method at T = 28 K are discussed. The required numbers of transfer units at the top and bottom column sections are calculated for different loads. The experimental characteristics of packed rectification columns are presented and examples of the cascade are discussed. A configuration for a cryogenic circuit based on a high-pressure throttle neon cycle with intermediate nitrogen cooling is presented. The necessity for and the technical feasibility of creating a driver pressure difference between the columns for different stages are demonstrated.

Bondarenko, V. L.; Simonenko, Yu. M.; Diachenko, O. V.; Matveyev, E. V.

2013-05-01

135

Comparison of the incremental and hierarchical methods for crystalline neon.  

PubMed

We present a critical comparison of the incremental and hierarchical methods for the evaluation of the static cohesive energy of crystalline neon. Both of these schemes make it possible to apply the methods of molecular electronic structure theory to crystalline solids, offering a systematically improvable alternative to density functional theory. Results from both methods are compared with previous theoretical and experimental studies of solid neon and potential sources of error are discussed. We explore the similarities of the two methods and demonstrate how they may be used in tandem to study crystalline solids. PMID:21386379

Nolan, S J; Bygrave, P J; Allan, N L; Manby, F R

2010-02-03

136

Primitive neon from the center of the Galápagos hotspot  

NASA Astrophysics Data System (ADS)

We present new helium and neon measurements in dredged basaltic glasses from the Western Galápagos, with an emphasis on the submarine flanks of Fernandina volcano, but including the adjacent flanks of Darwin, Ecuador, Wolf, and Roca Redonda. The samples from the submarine flanks of Fernandina volcano have the least radiogenic helium and neon; 3He/ 4He ratios vary from 18 to 29 times atmospheric (Ra), which spans the range previously observed at subaerial Fernandina. Samples from north of Fernandina have 3He/ 4He ratios closer to Mid-ocean ridge basalt (MORB) values (7.6 to 11.8 Ra), and are similar to subaerial lava flows from Darwin, Ecuador, Wolf, and Roca Redonda volcanoes. On a three-isotope neon diagram, the new submarine Fernandina data define a line that is closer to "solar" than data from Hawaii and Iceland, and therefore are among the least radiogenic, most primitive, neon isotopic compositions found on Earth. In contrast, the northern dredges have neon isotopic compositions similar to MORB. This sharp isotopic contrast between Fernandina and the adjacent volcanoes, whose summit calderas are only 35 to 40 km apart, is consistent with the hypothesis that Fernandina lies over the hotspot center. Measured 3He/ 22Ne ratios, coupled with helium and neon isotopic systematics show that 3He/ 22Ne values are extremely low in the Fernandina samples compared to the northern dredges. Coupled crushing and melting experiments show that vesicles often have lower 20Ne/ 22Ne and higher 3He/ 22Ne, suggesting that vesicle formation is not necessarily in solubility equilibrium, and that vesicles are preferentially affected by atmospheric contamination (as compared to host glass). There is a crude correlation between Mg# and total helium content in the glasses, suggesting that fractionation/degassing in a shallow magma reservoir is a primary control on noble gas contents. Due to similarities in volcanic plumbing between the Galápagos volcanoes, and in major and trace elements, the large 3He/ 22Ne variations (extrapolated to solar neon) between Fernandina (1.5) and the northern dredges (15) may be related to mantle source characteristics rather than the effects of recent degassing or melting. Simple closed-system evolution models show that the unradiogenic neon isotopic compositions require preservation since the first few hundred million years of Earth history, which is consistent with undegassed material in the lower mantle.

Kurz, Mark D.; Curtice, Joshua; Fornari, Dan; Geist, Dennis; Moreira, Manuel

2009-08-01

137

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

NASA Astrophysics Data System (ADS)

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.

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

1991-01-01

138

Fractionation of urea-pretreated squid visceral oil ethyl esters  

Microsoft Academic Search

Ethyl esters of squid (Illex argentinus) visceral oil contained 11.8% eicosapentaenoic acid (EPA) and 14.9% docosahexaenoic acid (DHA). The esters were treated with\\u000a urea to increase the contents of EPA and DHA. The non-urea complexing ethyl esters of squid visceral oil contained 28.2% EPA\\u000a and 35.6% DHA. This mixture was fractionated by molecular distillation to further increase the EPA or

Lucy Sun Hwang

2001-01-01

139

High transition-temperature SQUID magnetometers and practical applications  

SciTech Connect

The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (YBCO) are described. Essential to the achieving high magnetic field resolution at low frequencies is the elimination of 1/f flux noise due to thermally activated hopping of flux vortices between pinning sites in the superconducting films. Through improvements in processing, 1/f noise in single layer YBCO thin films and YBCO-SrTiO{sub 3}-YBCO trilayers was systematically reduced to allow fabrication of sensitive SQUID magnetometers. Both single-layer directly coupled SQUID magnetometers and multilayer magnetometers were fabricated, based on the dc SQUID with bicrystal grain boundary Josephson junctions. Multilayer magnetometers had a lower magnetic field noise for a given physical size due to greater effective sensing areas. A magnetometer consisting of a SQUID inductively coupled to the multiturn input coil of a flux transformer in a flip-chip arrangement had a field noise of 27 fT Hz{sup {minus}1/2} at 1 Hz and 8.5 fT Hz{sup {minus}1/2} at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz{sup {minus}1/2} at 1 Hz and 18 fT Hz{sup {minus}1/2} at 1 kHz. A three-axis SQUID magnetometer for geophysical applications was constructed and operated in the field in the presence of 60 Hz and radiofrequency noise. Clinical quality magnetocardiograms were measured using multilayer SQUID magnetometers in a magnetically shielded room.

Dantsker, E. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

1997-05-01

140

XRD studies of ?-chitin from squid pen with calcium solvent  

Microsoft Academic Search

The crystalline structure of ?-chitin from squid pen was investigated by X-ray diffraction (XRD). The purified ?-chitin was prepared from bigfin reefsquid pen. ?-Chitin was treated with saturated calcium chloride dihydrate\\/alchohol (CaCl2·2H2O\\/MeOH) solvent system at different conditions for XRD studies. The change of crystallinity of ?-chitin from squid pen was studied by using the fiber photographs on imaging plates. The

H. Nagahama; T. Higuchi; R. Jayakumar; T. Furuike; H. Tamura

2008-01-01

141

Research on high-Tc rf SQUID and its applications  

Microsoft Academic Search

We report on the research work at Peking University on optimizing high-temperature superconductor (HTS) rf superconducting quantum interference device (SQUID) systems and applying them in geophysical survey and magnetocardiography (MCG). Emphasis is placed on the design of comb-shape resonators for HTS rf SQUID systems and the experimental results of two applications: transient electromagnetics and MCG. The magnetic-field sensitivity of HTS

F. Wang; P. Ma; F. X. Xie; T. Yang; R. J. Nie; L. Y. Liu; S. Z. Wang; Y. D. Dai

2002-01-01

142

Effect of RF interference on characteristics of DC SQUID system  

Microsoft Academic Search

The effects of RF interference on the characteristics of DC superconducting quantum interference devices (SQUIDs) are investigated. The noise of a DC SQUID gradiometer radiating an RF field with a frequency between 100 kHz and 80 MHz was measured. As the RF field strength intensified, the white noise level increased and the cut-off frequency was lowered. The flux-voltage transfer function

N. Ishikawa; K. Nagata; H. Sato; N. Kasai; S. Kiryu

1993-01-01

143

Frequency-domain SQUID multiplexing of transition-edge sensors  

Microsoft Academic Search

We describe our frequency-domain readout multiplexer for transition-edge sensor (TES) bolometers and present measurements of an eight-channel multiplexer. Each sensor is biased with a sinusoidal bias at a distinct frequency. As the sensor absorbs power, it amplitude-modulates its sinusoidal bias. Sensor currents are summed and measured with a single superconducting quantum interference device (SQUID) array. The SQUID array consists of

T. M. Lanting; Hsiao-Mei Cho; J. Clarke; M. A. Dobbs; W. L. Holzapfel; A. T. Lee; M. Lueker; P. L. Richards; A. D. Smith; H. G. Spieler

2005-01-01

144

Giant Squid: One Gigantic Mystery (ScienceWorld)  

NSDL National Science Digital Library

This online article is from the Museum's Science Explorations, a collaboration between AMNH and Scholastic designed to promote science literacy. Written for students in grades 6-10, this article from Science World magazine has an interview with AMNH paleontologist Neal Landman, in which he discusses the giant squid and what scientists have been able to learn by studying only dead specimens. There are Web links that offer further opportunities for learning about the giant squid.

145

DC SQUID RF magnetometer with 200 MHz bandwidth  

NASA Astrophysics Data System (ADS)

Because of periodic flux-to-voltage transfer function, Superconducting QUantum Interference Device (SQUID) magnetometers operate in a closed-loop regime [1], which linearizes the response, and increases the dynamic range and sensitivity. However, a transmission line delay between the SQUID and electronics fundamentally limits the closed-loop bandwidth at 20 MHz [1], although the intrinsic bandwidth of SQUIDs is in gigahertz range. We designed a DC SQUID based RF magnetometer capable of wideband sensing coherent magnetic fields up to 200 MHz. To overcome the closed-loop bandwidth limitation, we utilized a low-frequency flux-modulated closed-loop to simultaneously lock the quasi-static magnetic flux and provide AC bias for the RF flux. The SQUID RF voltage is processed by RF electronics based on a double lock-in technique. This yields a signal proportional to the amplitude and phase of the RF magnetic flux, with more than four decades of a linear response. For YBaCuO SQUID on bi-crystal SrTiO substrate at 77 K we achieved a flux noise density of 4 ??0/Hz at 190 MHz, which is similar to that measured at kHz frequencies with conventional flux-locked loop. [1] D. Drung, et al., Supercond. Sci. Technol. 19, S235 (2006).

Talanov, Vladimir; Lettsome, Nesco; Orozco, Antonio; Cawthorne, Alfred; Borzenets, Valery

2012-02-01

146

Production of ?0 mesons and charged hadrons inbar v neon and ? neon charged current interactions  

NASA Astrophysics Data System (ADS)

The average multiplicities of charged hadrons and of ?+, ?- and ?0 mesons, produced inbar vNe and ?Ne charged current interactions in the forward and backward hemispheres of the W ±-nucleon center of mass system, are studied with data from BEBC. The dependence of the multiplicities on the hadronic mass ( W) and on the laboratory rapidity ( y Lab) and the energy fraction ( z) of the pion is also investigated. Special care is taken to determine the ?0 multiplicity accurately. The ratio of average ? multiplicities{2left< {n_{? ^O } } rightrangle }/{[left< {n_{? ^ + } rightrangle + left< {n_{? ^ - } } rightrangle ]}} is consistent with 1. In the backward hemisphereleft< {n_{? ^O } } rightrangle is positively correlated with the charged multiplicity. This correlation, as well as differences in multiplicities betweenmathop vlimits^{( - )} andmathop vlimits^{( - )} ,mathop vlimits^{( - )} scattering, is attributed to reinteractions inside the neon nucleus of the hadrons produced in the initialmathop vlimits^{( - )} interaction.

Wittek, W.; Aderholz, M.; Allport, P.; Armenise, N.; Baton, J. P.; Berggren, M.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P.; Giannakopoulos, N.; Guy, J.; Hoffmann, E.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Katz, U. F.; Kern, J.; Klein, H.; Marage, P.; Matsinos, E.; Morrison, D. R. O.; Neveu, M.; Parker, M. A.; Schmitz, N.; Simopoulou, E.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.

1988-06-01

147

Neon diffusion kinetics in olivine, pyroxene and feldspar: Retentivity of cosmogenic and nucleogenic neon  

NASA Astrophysics Data System (ADS)

We performed stepwise degassing experiments by heating single crystals of neutron- or proton-irradiated olivine, pyroxene and feldspar to study diffusion kinetics of neon. This is important in evaluating the utility of these minerals for cosmogenic 21Ne measurements and, potentially, for Ne thermochronometry. Degassing patterns are only partially explained by simple Arrhenius relationships; most samples do not exhibit a precisely-determined activation energy in an individual diffusion domain. Regardless, we find clear differences in diffusion kinetics among these minerals. Based on sub-selected data, our estimates for neon diffusion kinetics (activation energy Ea and pre-exponential factor Do, assuming the analyzed fragments approximate the diffusion domain) in each mineral are as follows: for the feldspars, Ea ranges from ˜65 to 115 kJ/mol and Do from 3.9 × 10-3 to 7.1 × 102 cm2s-1; for the pyroxenes, Ea ranges from ˜292 to 480 kJ/mol and Do from 1.6 × 102 to 2.9 × 1011 cm2s-1; for the olivines, Ea ranges from ˜360 to 370 kJ/mol and Do from 1.5 × 106 to 5.0 × 106 cm2s-1. Differences in these parameters are broadly consistent with the expected effect of structural differences between feldspar, and olivine and pyroxene. These results indicate that cosmogenic 21Ne will be quantitatively retained within olivine and pyroxene at Earth surface temperatures over geological timescales. The diffusion kinetics for feldspars, on the other hand, predicts that 21Ne retention at Earth surface temperatures will vary significantly with domain size, crystal microtexture, surface temperature, and exposure duration. Quantitative retention is expected only in favorable conditions. This conclusion is reinforced by additional measurements of cosmogenic 21Ne in coexisting quartz and feldspar from naturally irradiated surface samples; sanidine from a variety of rhyolitic ignimbrites exhibits quantitative retention, whereas alkali-feldspar from several granites does not.

Gourbet, Loraine; Shuster, David L.; Balco, Greg; Cassata, William S.; Renne, Paul R.; Rood, Dylan

2012-06-01

148

Functional theory of illusory conjunctions and neon colors  

Microsoft Academic Search

Illusory conjunctions are the incorrect perceptual combination of briefly presented colors and shapes. In the neon colors illusion, achromatic figures take on the color of an overlaid grid of colored lines. Both illusions are explained by a theory that assumes (a) poor location information or poor spatial resolution for some aspects of visual information and (b) that the spatial location

William Prinzmetal; Boaz Keysar

1989-01-01

149

Cosmogenic neon and helium at Reunion: Measurement of erosion rate  

Microsoft Academic Search

We report analyses of both helium and neon for olivine separates from a drill core at an altitude of 2330 m in oceanic at Piton de la Fournaise volcano. We show for the first time that cosmogenic Ne-21, like cosmogenic He-3, decreases exponentially with core depth. We obtain an attenuation length of 165 +\\/- 6 g\\/sq cm (1 sigma) for

Philippe Sarda; Thomas Staudacher; Claude J. Allegre; Andre Lecomte

1993-01-01

150

Molecular Iodine Fluorescence Using a Green Helium-Neon Laser  

ERIC Educational Resources Information Center

|Excitation of molecular iodine vapor with a green (543.4 nm) helium-neon laser produces a fluorescence spectrum that is well suited for the upper-level undergraduate physical chemistry laboratory. Application of standard evaluation techniques to the spectrum yields ground electronic-state molecular parameters in good agreement with literature…

Williamson, J. Charles

2011-01-01

151

A portable iodine stabilized helium-neon laser  

Microsoft Academic Search

A newly designed iodine stabilized helium-neon (He-Ne) laser is described which is stable to 3 x 10 to the -13th (1000-s sample time) but which exhibits an intensity dependent shift of about 8 kHz\\/W-sq cm. Closer agreement between dissimilar lasers is attained when the internal power densities are approximately equal.

Howard P. Layer

1980-01-01

152

NEON Data Products: Enabling Continental-Scale Ecological Science  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is a NSF-funded major research and facilities initiative under development, designed to address how climate change, land use change, and invasive species affect ecological science on a continental scale. The standardization of measurement methodologies, engineering practice, and data organization across NEON's sixty sites fosters the creation of ecological data products. These data products are community-approved and Observatory-vetted, and cover the breadth of NEON collection activities, including measurements of physical variables such as air, water, and soil temperature and chemistry, observations and analyses of species and habitats, and airborne spectral and LiDAR remote sensing. Together, these low-level (fundamental measurement and observation data)and high-level (integrative, continental-scale assessments) will be useful for scientists, students, educators, policymakers, and the general public. Here, we discuss the development status of NEON's data product suites, describing how they are constructed and vetted, and provide an example of how one current effort will provide several foundational data products. Further, we discuss and solicit feedback for how stakeholder communities can contribute to their veracity and validation.

Berukoff, S. J.

2011-12-01

153

Thermophysical properties of neon, argon, krypton, and xenon  

Microsoft Academic Search

Addressing the thermophysical properties of the rare gas elements - neon, argon, krypton, and xenon - this thorough work offers new research and uniform data. Tables cover properties in these elements crystalline, liquid, and gaseous states, spanning a temperature range of 0-1300 K, and for pressures up to 100 MPa. This volume contains thermodynamic properties in the solid phase and

V. A. Rabinovich; A. A. Vasserman; V. I. Nedostup; L. S. Veksler

1987-01-01

154

Neon and CO2 adsorption on open carbon nanohorns.  

PubMed

We present the results of a thermodynamics and kinetics study of the adsorption of neon and carbon dioxide on aggregates of chemically opened carbon nanohorns. Both the equilibrium adsorption characteristics, as well as the dependence of the kinetic behavior on sorbent loading, are different for these two adsorbates. For neon the adsorption isotherms display two steps before reaching the saturated vapor pressure, corresponding to adsorption on strong and on weak binding sites; the isosteric heat of adsorption is a decreasing function of sorbent loading (this quantity varies by about a factor of 2 on the range of loadings studied), and the speed of the adsorption kinetics increases with increasing loading. By contrast, for carbon dioxide there are no substeps in the adsorption isotherms; the isosteric heat is a nonmonotonic function of loading, the value of the isosteric heat never differs from the bulk heat of sublimation by more than 15%, and the kinetic behavior is opposite to that of neon, with equilibration times increasing for higher sorbent loadings. We explain the difference in the equilibrium properties observed for neon and carbon dioxide in terms of differences in the relative strengths of adsorbate-adsorbate to adsorbate-sorbent interaction for these species. PMID:23802764

Krungleviciute, Vaiva; Ziegler, Carl A; Banjara, Shree R; Yudasaka, Masako; Iijima, S; Migone, Aldo D

2013-07-19

155

A Closed Neon Liquefier System for Testing Superconducting Devices  

NASA Astrophysics Data System (ADS)

A Neon liquefier system has been developed by Southampton University (UK) and EDISON (Italy) with the aim to provide a facility for testing HTS superconducting devices using Magnesium Diboride materials, in the range 25-30K. The system consists of a liquid Neon cryostat coupled to a two stages cryocooler and a recovery system. The first stage of the cryocooler is connected to the thermal shield of the cryostat and a copper station positioned at mid point along the access neck to the liquid Neon bath to reduce heat leak and to provide pre-cooling of samples. The second stage, capable of 20W cooling power at 22K, is used to provide the cooling power for liquefaction and to refrigerate the liquid Neon bath and the superconducting device/sample during the steady state operation. The recovery system has been designed to automatically compress excess boil-off generated by a quench or a transient heating into a storage gas container. Transport measurement up to 900A can be carried out in the Ne cryostat using purposely build hybrid current leads. These leads have a copper upper section cooled by liquid Nitrogen and a superconducting lower section of Ag/AuBi2223 tapes. In this paper we report on the performance of the system and the initial measurement of superconducting samples.

Bianchetti, M.; Al-Mosawi, M. K.; Yang, Y.; Beduz, C.; Giunchi, G.

2006-04-01

156

New Neon Abundance Constraints in Wolf-Rayet Winds  

Microsoft Academic Search

The fast, dense winds which characterize Wolf-Rayet (WR) stars obscure their underlying cores, and complicate the verification of evolving core models. A powerful technique for probing WR core evolution involves measuring abundances of wind-borne nuclear processed elements. Neon in particular undergoes a remarkable abundance change during the later stages of a WR star's lifetime. By the end of carbon (WC)

J. D. T. Smith

2001-01-01

157

Desorption heat capacity of 3He adsorbed on solid neon  

Microsoft Academic Search

The desorption heat capacity of successive monolayers of 3He adsorbed on solid neon is measured and a rigid band model for the desorption is set up. The agreement between experiment and theory is good. The desorption energy varies between 55 and 25 K for the first layer as a function of coverage and is about 11 K for the second

Per Wennerström; Anders Törne; Torsten Lindqvist

1978-01-01

158

Momentum Distribution and Final State Effects in Liquid Neon  

Microsoft Academic Search

We report high precision inelastic neutron scattering measurements in liquid Neon at a temperature of 25.8 K and saturated vapour pressure. The data covers a wide range of energy and momentum transfer (2 ??1 ? Q ? 13 ??1). The atomic momentum distribution, n(p), and final state effects (FSE) can be readily extracted from this intermediate wavevector transfer data provided

R. T. Azuah; W. G. Stirling; H. R. Glyde; M. Boninsegni

1997-01-01

159

Airborne remote sensing instrumentation for NEON: Status and development  

Microsoft Academic Search

Airborne remote sensing plays a crucial role in the scaling strategy underpinning the National Ecological Observatory Network (NEON) design. 12 Airborne spectroscopy will quantify plant species type and function, and waveform LiDAR will quantify vegetation structure and heterogeneity at the scale of individual shrubs and larger plants over hundreds of square kilometers. Digital imagery at better than 30 cm resolution

Thomas U. Kampe; Brian R. Johnson; Michele Kuester; Joel McCorkel

2011-01-01

160

Presence of mature eggs in olive fruit fly, Bactrocera oleae (Diptera Tephritidae), at different constant photoperiods and at two temperatures  

Microsoft Academic Search

The effect of the constant photoperiod on presence of mature eggs in olive fruit fly was investigated. Adults of B. oleae were submitted to different photoperiodic treatments (LL:DD), at temperature of 20 °C: 9:15, 10:14, 12:12, 15:9, 16:8, continuous light (LL) and continuous dark (DD). Light was obtained from neon tubes and the light intensity, estimated inside the plexiglas cage,

Alfio RASPI; Angelo CANALE; Augusto LONI

161

Direct detection of dark matter with liquid argon and neon  

NASA Astrophysics Data System (ADS)

There is a great deal of observational evidence across a wide variety of scales that a large fraction of the universe and most of the matter in the universe is made up of some form of non-baryonic, dark matter. The most prominent candidate for dark matter is the weakly interacting massive particle or WIMP, with a mass between 1 GeV to a few TeV, and there are many current experiments aiming to detect these particles directly. The DEAP/CLEAN program seeks to detect dark matter and pp-solar neutrinos using liquid argon and liquid neon as targets. When ionizing radiation interacts in these liquids, scintillation light is produced. The timing or pulse shape of scintillation provides pulse shape discrimination (PSD) with which to identify the type of recoil that occurred in the liquid. As WIMP-nucleus scattering events would produce nuclear recoils but most of the backgrounds produce electronic recoils, PSD provides background rejection, allowing liquid argon- and neon-based detectors to achieve excellent sensitivity to dark matter. In this work, I describe the evidence for dark matter and review the state of current detection efforts. I then discuss observations of scintillation in liquid argon and liquid neon performed in prototype detectors at Yale and underground at SNOLAB in Ontario, Canada, focusing on measurements of PSD, the nuclear recoil scintillation efficiency and alpha backgrounds in these detectors. I describe the implications of these measurements for both the argon and neon components of the DEAP/CLEAN program, including simulations of a possible 10-tonne liquid neon detector. In the first appendix, I describe efforts at Yale to build a thermal column for the separation of isotopes, with applications to both dark matter and neutrinoless double-beta decay searches. In the second appendix, I describe operation of an evaporator system.

Lippincott, W. Hugh

2010-12-01

162

Flux noise in SQUIDs: Effects of deposited surface films  

NASA Astrophysics Data System (ADS)

Magnetic flux noise in SQUIDs and superconducting qubits with a spectral density S?(f) scaling as 1/(f/1 Hz)^? is understood to arise from the random reversal of spins localized at the surface of the superconducting film. We present experimental results showing the effects on S?(f) of Au, SiNx, NbN, and Al2O3 films deposited on the upper surface of Nb and NbN dc SQUID loops. For each measurement, we fabricated six identical SQUIDs on a single chip and then capped the surface of either half or all the SQUID loops. Certain capping layers, such as Au, had no discernible effect on S?(f) with regard to the magnitude, slope ?, and temperature dependence. On the other hand, some capping layers significantly reduced S?(1 Hz)---by a factor of about two in the case of SiNx. Furthermore, some layers significantly affected the value of ? and the temperature dependence of both S?(1 Hz) and ?. These results further establish the importance of the role of the surface of the SQUID loop on its flux noise. We discuss implications for microscopic models of flux noise in light of these measurements.

O'Kelley, S. R.; Anton, S. M.; Birenbaum, J. S.; Clarke, John; Hilton, G. C.; Cho, H.-M.; Irwin, K. D.; Nugroho, C. D.; Dove, A. F.; Olson, G. A.; Yoscovits, Z. R.; Orlyanchik, V.; van Harlingen, D. J.; Eckstein, J. N.

2013-03-01

163

Fabrication and characterization of a switchable flux transformer using a DC-SQUID  

Microsoft Academic Search

We have investigated a switchable flux transformer which consists of a superconducting loop and a DC-SQUID. The effective magnetic flux in the DC-SQUID was controlled by a control current, which was injected in the segment of the SQUID loop. The equation describing the behavior of the circulating current in the transformer was derived. We fabricated the flux transformer coupled with

Y. Shimazu; T. Niizeki; Y. Wada

2006-01-01

164

Effect of radiofrequency pumping conditions on Josephson generation frequency in a resistive SQUID  

Microsoft Academic Search

The dependence on the rf pumping power of the Josephson generation frequency f\\/sub J\\/ in a hysteresis SQUID with a single weak contact is detected and studied experimentally. The dependence shows up in the first plateau of the current-voltage characteristic of the oscillatory circuit associated with the resistive SQUID. When a dc current Iâ was transmitted through the SQUID in

B. V. Vasilev; G. S. Krivoi

1982-01-01

165

RANGE EXPANSION AND TROPHIC INTERACTIONS OF THE JUMBO SQUID, DOSIDICUS GIGAS, IN THE CALIFORNIA CURRENT  

Microsoft Academic Search

Although jumbo squid (Dosidicus gigas) have been oc- casional visitors to the California Current over the last century, their abundance and distribution increased be- tween 2002 and 2006. We report several time series of jumbo squid relative abundance from commercial and recreational fisheries as well as resource surveys and food habits studies. To evaluate the trophic relationships of jumbo squid,

JOHN C. FIELD; KEN BALTZ; A. JASON PHILLIPS

166

SQUID magnetometers for biomagnetism and nondestructive testing: important questions and initial answers  

Microsoft Academic Search

For two decades, academic and industrial researchers worldwide have used SQUID magnetometers to measure magnetic signals from the heart, brain, lungs, liver, nerves, skeletal muscle, stomach, intestines, eyes, and other organs, and have invested heavily in developing and promoting this technology. While there are as yet few accepted clinical applications of SQUIDs, various trends are encouraging. The introduction of SQUIDs

1995-01-01

167

Collective quantum tunneling, ultimate sensitivity of the AC SQUID, and all that  

Microsoft Academic Search

The effect of quantum tunneling of the phase variable in SQUIDs is studied as a source of zero-temperature noise in the system. It is concluded that quantum tunneling plays no role in the ultimate uncertainty principle limitation of SQUID resolution. A simple expression is derived for the latter in practical SQUIDs.

J. Kurkijärvi

1981-01-01

168

How and why do flying fish fly?  

Microsoft Academic Search

Summary 1.The review is concerned mainly with exocoetid flying fish, because little reliable information is available concerning other groups.2.Adult flying fish are of variable size (150–500 mm maximum length) and may be broadly divided into two categories: ‘two-wingers’ (e.g.Fodiator, Exocoetus, Parexocoetus) in which the enlarged pectoral fins make up most of the lifting surfaces, and ‘four-wingers’ (e.g.Cypsilurus, Hirundichthys) in which

John Davenport

1994-01-01

169

Evidence of weak plasma series resonance heating in the H-mode of neon and neon/argon inductively coupled plasmas  

NASA Astrophysics Data System (ADS)

Phase-resolved optical emission spectroscopy measurements in argon and neon inductively coupled plasmas (ICPs) have revealed a surplus of high-energy electrons in neon-containing plasmas. Differences between results of emission model analyses using neon and argon lines (as well as probe measurements) also indicate a high-energy enhancement in neon-containing plasmas. The abundance of these extra high-energy electrons is correlated with the sheath thickness near the rf antenna and can be reduced by either adding a Faraday shield (external shielding) or increasing the plasma density. A comparison of modelled and experimental values of the 13.56 MHz time modulation of select neon emission lines strongly suggests plasma series resonance heating adjacent to the ICP antenna as the source of the extra heating.

Boffard, John B.; Jung, R. O.; Lin, Chun C.; Aneskavich, L. E.; Wendt, A. E.

2012-09-01

170

Bio-application of high-Tc SQUID magnetic sensor  

NASA Astrophysics Data System (ADS)

We propose medical applications using ultra-small magnetic particles and a SQUID magnetic sensor. A high-Tc SQUID system for biological molecules (DNA) detection is one of that. This system is based on a hybridization process. Two strands in a DNA molecule are held together by hydrogen bonds between base pairs like a ladder. The two strands are referred to as being complementary to each other. One strand (sample DNA) was labeled with Fe3O4 ultra-small magnetic particles and the other (probe DNA) was anchored on a glass slide. Then they were hybridized each other on the slide. After washing the excess sample DNA, the hybridized DNA was evaluated in the presence of excitation AC field by high-Tc SQUID. The signal was initially proportional to the concentration of the sample DNA and then saturated. It means that the hybridization occurred successfully between the sample DNA and the probe DNA.

Tanaka, Saburo; Aspanut, Zarina; Kurita, Hirofumi; Toriyabe, Chika; Hatuskade, Yoshimi; Katsura, Shinji

2006-05-01

171

Ionized calcium concentrations in squid axons  

PubMed Central

Values for ionized [Ca] in squid axons were obtained by measuring the light emission from a 0.1-mul drop of aequorin confined to a plastic dialysis tube of 140-mum diameter located axially. Ionized Ca had a mean value of 20 x 10(-9) M as judged by the subsequent introduction of CaEGTA/EGTA buffer (ratio ca. 0.1) into the axoplasm, and light measurement on a second aequorin drop. Ionized Ca in axoplasma was also measured by introducing arsenazo dye into an axon by injection and measuring the Ca complex of such a dye by multichannel spectrophotometry. Values so obtained were ca. 50 x 10(-9) M as calibrated against CaEGTA/EGTA buffer mixtures. Wth a freshly isolated axon in 10 mM Ca seawater, the aequorin glow invariably increased with time; a seawater [Ca] of 2-3 mM allowed a steady state with respect to [Ca]. Replacement of Na+ in seawater with choline led to a large increase in light emission from aequorin. Li seawater partially reversed this change and the reintroduction of Na+ brought light levels back to their initial value. Stimulation at 60/s for 2-5 min produced an increase in aequorin glow about 0.1% of that represented by the known Ca influx, suggesting operationally the presence of substantial Ca buffering. Treatment of an axon with CN produced a very large increase in aequorin glow and in Ca arsenazo formation only if the external seawater contained Ca.

1976-01-01

172

Isotopically anomalous neon in meteoritic nanodiamonds: Formation during type II supernova explosions  

NASA Astrophysics Data System (ADS)

We hypothesize the formation of neon associated with isotopically anomalous xenon (Xe-HL) in meteoritic nanodiamonds and designated as Ne-X through the mixing of the Ne-HL and Ne-S subcomponents. The Ne-HL subcomponent is neon from the helium (He/C) zone of a type II supernova or a mixture of neon from this zone and its hydrogen zone, while the Ne-S subcomponent is spallation neon formed during a supernova explosion in nuclear spallation reactions induced by high-energy protons. Based on this hypothesis and the presumed abundances of neon isotopes in the zones of a high-mass (25 M ?) supernova after its explosion, we have calculated the abundances of neon components in nanodiamond separates and its grain-size fractions. Our calculations have shown the following. (1) The main source of Ne-HL is neon from the helium zone of the supernova; as a result, the 20Ne/22Ne and 21Ne/22Ne ratios for Ne-X are 0.26 ± 0.03 and 0.19 ± 0.04, respectively. The isotopic composition of Ne-X is identical to that for Ne-A2 if Ne-HL is produced by the mixing of neon from the helium and hydrogen zones in proportion 1: 1.06. (2) In meteoritic nanodiamonds, the main neon abundance is determined by neon of the P3 component (Ne-P3). Ne-P3 is retained during thermal metamorphism, because it is sited in traps of the crystal lattice of diamond with a high energy of its activation. (3) The Ne-X/Ne-P3 ratio increases with nanodiamond grain size; as a result, there is no need to invoke an additional neon component (Ne-P6) to interpret the data on neon in meteoritic nanodiamonds.

Fisenko, A. V.; Semenova, L. F.

2008-09-01

173

Output power and gain at the 5.4-micron laser transition in pure neon  

Microsoft Academic Search

The output power and gain at the 5.4-micron laser transition (3p1-3s1) in pure neon (active element length, 60 cm) are determined experimentally for various neon pressures and discharge currents. The results obtained indicate that pure-neon lasers emitting at 5.4 microns can be advantageously used for the analysis of microscopic concentrations of nitrogen oxide.

S. A. Boiko; A. I. Popov

1988-01-01

174

Using SQUIDs to Detect Charge in Cryogenic Germanium Detectors  

NASA Astrophysics Data System (ADS)

This paper describes an impedance matching network which allows charge impulses to be measured by a SQUID amplifier with an RMS charge noise of less than 100 e, assuming the SQUID amplifier has a current noise of 2 pA/sqrt{Hz}, and the current pulse has a duration of about 1 ?s or shorter. The component values are provided for an example system which has an RMS charge noise of 91 e, assuming all dissipative circuit elements are cooled to a temperature of 100 mK.

Moffatt, R. A.; Cabrera, B.; Kadribasic, F.; Pyle, M.; Wesenberg, D.; Yen, J. J.; Young, B. A.

2012-06-01

175

Swimming dynamics and propulsive efficiency of squids throughout ontogeny.  

PubMed

Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures, whereas juveniles and adults operate at higher Re and generally have more streamlined bodies, larger fins, and relatively small funnel apertures. These morphological changes and varying flow conditions affect swimming performance in squids. To determine how swimming dynamics and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV) and kinematic data were collected from an ontogenetic range of long-finned squid Doryteuthis pealeii and brief squid Lolliguncula brevis swimming in a holding chamber or water tunnel (Re = 20-20 000). Jet and fin wake bulk properties were quantified, and propulsive efficiency was computed based on measurements of impulse and excess kinetic energy in the wakes. Paralarvae relied predominantly on a vertically directed, high frequency, low velocity jet as they bobbed up and down in the water column. Although some spherical vortex rings were observed, most paralarval jets consisted of an elongated vortical region of variable length with no clear pinch-off of a vortex ring from the trailing tail component. Compared with paralarvae, juvenile and adult squid exhibited a more diverse range of swimming strategies, involving greater overall locomotive fin reliance and multiple fin and jet wake modes with better defined vortex rings. Despite greater locomotive flexibility, jet propulsive efficiency of juveniles/adults was significantly lower than that of paralarvae, even when juvenile/adults employed their highest efficiency jet mode involving the production of periodic isolated vortex rings with each jet pulse. When the fins were considered together with the jet for several juvenile/adult swimming sequences, overall propulsive efficiency increased, suggesting that fin contributions are important and should not be overlooked in analyses of the swimming performance of squids. The fins produced significant thrust and consistently had higher propulsive efficiency than did the jet. One particularly important area of future study is the determination of coordinated jet/fin wake modes that have the greatest impact on propulsive efficiency. Although such research would be technically challenging, requiring new, powerful, 3D approaches, it is necessary for a more comprehensive assessment of propulsive efficiency of the squid dual-mode locomotive system. PMID:21669828

Bartol, Ian K; Krueger, Paul S; Thompson, Joseph T; Stewart, William J

2008-05-20

176

Squid detected NMR and MRI at ultralow fields  

DOEpatents

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.

Clarke, John (Berkeley, CA); McDermott, Robert (Louisville, CO); Pines, Alexander (Berkeley, CA); Trabesinger, Andreas Heinz (CH-8006 Zurich, CH)

2007-05-15

177

TOPICAL REVIEW: Radio-frequency amplifiers based on dc SQUIDs  

NASA Astrophysics Data System (ADS)

SQUIDs are an attractive candidate for the amplification of low-level rf and microwave signals. Compared to semiconductor amplifiers, they offer lower noise and much lower power dissipation. Especially at frequencies below 1 GHz, the improvement in noise temperature compared to the best cold semiconductor amplifiers can be as high as 50; noise temperatures only slightly above the quantum limit have been achieved in this frequency range. This article will review the current status of radio-frequency amplifiers based on dc SQUIDs and provide detailed discussions of amplifier noise temperature, input and output impedance, and nonlinearities.

Mück, Michael; McDermott, Robert

2010-09-01

178

Low-noise FET amplifier for dc SQUID  

SciTech Connect

We report on the design, characterization, and operation of a low-noise FET-input differential amplifier, which is used as second stage for a dc SQUID in the electronic instrumentation of the gravitational wave detector of the Rome group at CERN. The 3-dB bandwidth of the amplifier is from 10 kHz to 1.5 MHz. At the SQUID modulation frequency of 70 kHz the voltage noise is 0.5 nV/(Hz){sup 1/2}, the current noise is 35 fA/(Hz){sup 1/2}.

Pallottino, G.V.; Lupi, T. (Dipartimento di Fisica, Universita La Sapienze,'' Rome (Italy))

1990-09-01

179

Dipole location using SQUID based measurements: Application to magnetocardiography  

NASA Astrophysics Data System (ADS)

We report a method of inferring the dipole location using iterative nonlinear least square optimization based on Levenberg-Marquardt algorithm, wherein, we use different sets of pseudo-random numbers as initial parameter values. The method has been applied to (i) the simulated data representing the calculated magnetic field distribution produced by a point dipole placed at a known position, (ii) the experimental data from SQUID based measurements of the magnetic field distribution produced by a source coil carrying current, and (iii) the actual experimentally measured magnetocardiograms of human subjects using a SQUID based system.

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

2012-07-01

180

Research on high-Tc rf SQUID and its applications  

NASA Astrophysics Data System (ADS)

We report on the research work at Peking University on optimizing high-temperature superconductor (HTS) rf superconducting quantum interference device (SQUID) systems and applying them in geophysical survey and magnetocardiography (MCG). Emphasis is placed on the design of comb-shape resonators for HTS rf SQUID systems and the experimental results of two applications: transient electromagnetics and MCG. The magnetic-field sensitivity of HTS magnetometers is now adequate for MCG applications. However, in order to be commercially used, the system still needs some improvements: development of suitable gradiometers and multi-channel systems.

Wang, F.; Ma, P.; Xie, F. X.; Yang, T.; Nie, R. J.; Liu, L. Y.; Wang, S. Z.; Dai, Y. D.

2002-12-01

181

Isolation and characterization of collagen from squid ( Ommastrephes bartrami) skin  

NASA Astrophysics Data System (ADS)

Collagen of squid ( Ommastrephes bartrami) skin was examined in the present study. Histology showed that collagen fiber in the skin was partially cross-linked with muscle fiber. Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were extracted from the skin and characterized. The results of amino acid composition and electrophoretic patterns revealed that ASC and PSC were both type I collagen, containing ?1 and ?2 chains. FTIR (fourier transform infrared spectroscopy) investigations confirmed the existence of helical arrangements in PSC of squid skin. The denaturation temperature (Td) and shrinkage temperature (Ts) of PSC were 29.4°C and 52.8°C, respectively.

Yan, Mingyan; Li, Bafang; Zhao, Xue

2009-06-01

182

A dielectric barrier discharge in neon at atmospheric pressure  

NASA Astrophysics Data System (ADS)

A dielectric barrier discharge in neon at atmospheric pressure is investigated with electrical measurement and fast photography. It is found that a stable diffuse discharge can be easily generated in a gap with a gap space of 0.5-6 mm and is identified with a glow discharge. The first breakdown voltage of the gap is considerably higher than that of the same gap working in a stable diffuse discharge mode, which indicates that Penning ionization of neon metastables from the previous discharge with inevitable gas impurities plays an important role in the decrease in the breakdown voltage. Discharge patterns are observed in a gap shorter than 1 mm. From the experiments with a wedge-like gap, it is found that the discharge patterns are formed in the area with a higher applied electric field, which suggests that a higher applied electric field may cause a transition from a diffuse glow to discharge patterns.

Ran, Junxia; Luo, Haiyun; Wang, Xinxin

2011-08-01

183

A Cyberinfrastructure for the National Ecological Observatory Network (NEON).  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is an NSF-funded project designed to provide physical and information infrastructure to support the development of continental-scale, quantitative ecological sciences. The network consists of sixty sites located in the continental US, Alaska, Hawaii, and Puerto Rico, each site hosting terrestrial and aquatic sensors and observational apparati that acquire data across multiple ecoclimatic domains. As well, an airborne remote sensing platform provides spectral and LiDAR data, and acquisition of data sets from external agencies allows for land-use studies. Together, this data is ingested, vetted, processed, and curated by a standards-based, provenance-driven, metadata-rich cyberinfrastructure, which will provide not only access to but discovery and manipulation of NEON data, and the construction of integrative data products and inputs for ecological forecasting that address fundamental processual questions in climate change, land use change, and invasive species.

Schimel, D.; Berukoff, S. J.

2011-12-01

184

Heteronuclear collisions between laser-cooled metastable neon atoms  

NASA Astrophysics Data System (ADS)

We investigate heteronuclear collisions in isotope mixtures of laser-cooled metastable (3P2) neon. Experiments are performed with spin-polarized atoms in a magnetic trap for all two-isotope combinations of the stable neon isotopes 20Ne, 21Ne, and 22Ne. We determine the rate coefficients for heteronuclear ionizing collisions to ?21,20=(3.9±2.7)×10-11 cm3/s, ?22,20=(2.6±0.7)×10-11 cm3/s, and ?21,22=(3.9±1.9)×10-11 cm3/s. We also study heteronuclear elastic collision processes and give upper bounds for heteronuclear thermal relaxation cross sections. This work significantly extends the limited available experimental data on heteronuclear ionizing collisions for laser-cooled atoms involving one or more rare gas atoms in a metastable state.

Schütz, Jan; Feldker, Thomas; John, Holger; Birkl, Gerhard

2012-08-01

185

Acoustic target strength of Japanese common squid, todarodes pacificus, and important parameters influencing its TS: swimming angle and material properties  

Microsoft Academic Search

The squids, one of the cephalopods, is important species in fisheries and ecology. If acoustic properties of squid can be well examined, especially target strength (TS), acoustic method can be provided a good tool for squid survey. The purpose of the study is to investigate the TS property of the Japanese common squid, Todarodes pacificus, and parameters influencing TS: swimming

Donhyug Kang; K. Iida; T. Mukai; Doojin Hwang

2004-01-01

186

Primitive neon isotopes in Terceira Island (Azores archipelago)  

Microsoft Academic Search

We present the first neon data, as well as new helium data, on Terceira Island (Azores archipelago, Portugal). Clear 20Ne and 21Ne excesses compared to air are observed (20Ne\\/22Ne>11.2) and moreover, the samples show a more primitive 21Ne\\/22Ne ratio than MORB, confirming that the Azores hotspot can be considered as sampling a “primitive”, relatively undegassed, reservoir. Most 4He\\/3He isotopic ratios

Pedro Madureira; Manuel Moreira; João Mata; Claude Jean Allègre

2005-01-01

187

Charge radii of neon isotopes across the sd neutron shell  

SciTech Connect

We report on the changes in mean square charge radii of unstable neon nuclei relative to the stable {sup 20}Ne, based on the measurement of optical isotope shifts. The studies were carried out using collinear laser spectroscopy on a fast beam of neutral neon atoms. High sensitivity on short-lived isotopes was achieved thanks to nonoptical detection based on optical pumping and state-selective collisional ionization, which was complemented by an accurate determination of the beam kinetic energy. The new results provide information on the structural changes in the sequence of neon isotopes all across the neutron sd shell, ranging from the proton drip line nucleus and halo candidate {sup 17}Ne up to the neutron-rich {sup 28}Ne in the vicinity of the ''island of inversion.'' Within this range the charge radius is smallest for {sup 24}Ne with N=14 corresponding to the closure of the neutron d{sub 5/2} shell, while it increases toward both neutron shell closures, N=8 and N=20. The general trend of the charge radii correlates well with the deformation effects which are known to be large for several neon isotopes. In the neutron-deficient isotopes, structural changes arise from the onset of proton-halo formation for {sup 17}Ne, shell closure in {sup 18}Ne, and clustering effects in {sup 20,21}Ne. On the neutron-rich side the transition to the island of inversion plays an important role, with the radii in the upper part of the sd shell confirming the weakening of the N=20 magic number. The results add new information to the radii systematics of light nuclei where data are scarce because of the small contribution of nuclear-size effects to the isotope shifts which are dominated by the finite-mass effect.

Marinova, K. [Institut fuer Physik, Universitaet Mainz, D-55099 Mainz (Germany); Laboratory of Nuclear Reactions, Joint Institute of Nuclear Research, 141980 Dubna (Russian Federation); Geithner, W.; Kappertz, S.; Kloos, S.; Kotrotsios, G.; Neugart, R.; Wilbert, S. [Institut fuer Physik, Universitaet Mainz, D-55099 Mainz (Germany); Kowalska, M.; Keim, M. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Blaum, K. [Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Lievens, P. [Laboratorium voor Vaste-Stoffysica en Magnetisme, K.U.Leuven, B-3001 Leuven (Belgium); Simon, H. [Institut fuer Kernphysik, TU Darmstadt, D-64289 Darmstadt (Germany)

2011-09-15

188

Atomic Mass and Nuclear Binding Energy for Ne-21 (Neon)  

NASA Astrophysics Data System (ADS)

This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Ne-21 (Neon, atomic number Z = 10, mass number A = 21).

Sukhoruchkin, S. I.; Soroko, Z. N.

189

Neon puffing experiments in the JIPP T-IIU tokamak  

Microsoft Academic Search

Large amounts of neon were puffed into the discharge of the JIPP T-IIU tokamak, producing values of effective ion charge, Z sub eff, as large as 6 or 7 at linear average electron density bar n sub e, up to 3.5 x 10 to the 13th\\/cu cm. Electron temperatures, T sub e, rise to about twice those obtained in hydrogen

E. Meservey; K. Toi; R. Ando; R. Bell; S. Hirokura; R. Hulse; K. Kawahata; Y. Kawasumi; S. Morita; I. Ogawa

1988-01-01

190

Secondary ionization mechanisms in the electrical breakdown of neon  

Microsoft Academic Search

The formative time lags for nickel electrodes in neon have been measured over the reduced-pressure range 20-60 torr (reduced to 0°C) and the E\\/N range (field per unit concentration) from 4·3 × 10-16 to 7·5 × 10-16 v cm2. A temporal growth theory by Davidson, with adjustable parameters, was used to calculate theoretical formative time lags to fit the experimental

M J Fulker

1967-01-01

191

Isotopes of cosmic ray elements from neon to nickel  

Microsoft Academic Search

Results obtained from a balloon exposure of a cosmic ray detector flown in 1977 are reported. The charge resolution ranged from 0.19 to 0.21 charge units between neon and nickel and the mass resolution for nuclei stopped in the emulsions ranged from 0.40 to 0.70 amu for A between 20 and 60 amu. This was enough to correctly identify almost

C. J. Waddington; P. S. Freier; R. K. Fickle; N. R. Brewster

1981-01-01

192

Multilayer isotherms of neon adsorbed on exfoliated graphite  

Microsoft Academic Search

Isotherms of neon adsorbed on compressed exfoliated graphite were measured, using a standard volumetric method, in the temperature\\u000a interval of 12–24 K for the four first layers. The critical temperatures for the first three layers were determined to be\\u000a 16.01.0, 19.01.0 K, and 18.01.0 K, respectively. From the isotherms, the isosteric heats of adsorption were calculated\\u000a as a function of

F. Hanono; C. E. N. Gatts; E. Lerner

1985-01-01

193

Equation of state for solid neon to 20 kbar  

Microsoft Academic Search

Piston-displacement equation-of-state (EOS) data to 20 kbar which are consistent with existingP=0 thermal expansion and bulk modulus data are given for solid neon for three isotherms (4.2, 13.5, and 19.9 K). A Mie-Grüneisen EOS can be used to correlate these results with data from directCVmeasurements at several molar volumes if the Grüneisen parameter is assumed to be proportional to the

M. S. Anderson; R. Q. Fugate; C. A. Swenson

1973-01-01

194

Momentum distribution and final state effects in liquid neon  

Microsoft Academic Search

We report high precision inelastic neutron scattering measurements in liquid Neon at a temperature of 25.8 K and saturated\\u000a vapour pressure. The data covers a wide range of energy and momentum transfer (2 ?1?Q?13?1 The atomic momentum distribution,n(p), and final state effects (FSE) can be readily extracted from this intermediate wavevector transfer data provided a suitable\\u000a method of analysis is

R. T. Azuah; W. G. Stirling; H. R. Glyde; M. Boninsegni

1997-01-01

195

Adsorption of 4He on neon-coated exfoliated graphite  

Microsoft Academic Search

Adsorption isotherms of 4He on Grafoil coated with a monolayer of neon were made for the temperature range of 2–10 K and in the pressure range of 0.10–15.00 Torr, using a standard volumetric method. From these isotherms the isosteric heats of adsorption were calculated as a function of coverage. The binding energy of 4He on Ne was obtained from the

F. Hanono; E. Lerner

1980-01-01

196

Phases of neon monolayers adsorbed on basal plane graphite  

Microsoft Academic Search

The first monolayer of neon adsorbed on exposed basal planes of graphite has been explored in detail by means of heat capacity measurements on 15 different coverages ranging from 0.06 to 0.91 monolayer for 1.25< T<20 K. Experimental resolution and reproducibility were enhanced by means of an on-line minicomputer. The heat capacity signatures indicate a 2D triple point at 13.5

G. B. Huff; J. G. Dash

1976-01-01

197

Phases of neon monolayers adsorbed on basal plane graphite  

Microsoft Academic Search

The first monolayer of neon adsorbed on exposed basal planes of graphite has been explored in detail by means of heat capacity measurements on 15 different coverages ranging from 0.06 to 0.91 monolayer for 1.25TTt,bulk=24.54 K) as well as several other transitions in the adsorbed films. Vapor pressure measurements extend from 0.5 monolayer to 1.5 monolayers for 19TTc,bulk=44.40 K).

G. B. Huff; J. G. Dash

1976-01-01

198

Equation of state for solid neon to 20 kbar  

Microsoft Academic Search

Piston-displacement equation-of-state (EOS) data to 20 kbar which are consistent with existing P=0 thermal expansion and bulk modulus data are given for solid neon for three isotherms (4.2, 13.5, and 19.9 K). A Mie-Grüneisen EOS can be used to correlate these results with data from direct C V measurements at several molar volumes if the Grüneisen parameter is assumed to

M. S. Anderson; R. Q. Fugate; C. A. Swenson

1973-01-01

199

Neon in carbon nanopores: wetting, growth mechanisms, and cluster structures  

Microsoft Academic Search

A low-temperature, high-energy (50 keV) electron diffraction study of size-dependent structures and growth mechanisms of neon samples in multiporous ``amorphous'' carbon films is presented. Electron diffractograms are analyzed on the basis of the assumption that there exists a cluster size distribution in deposits formed in the substrate, and multi-shell structures such as icosahedra, decahedra, and fcc and hcp clusters are

N. V. Krainyukova

2007-01-01

200

Experimental thermal expansions for solid neon, 2–14 K  

Microsoft Academic Search

Linear thermal expansion measurements are reported for free-standing samples of solid neon at temperatures from 2 to 14 K. After normalization, the results agree well with x-ray data in an overlap region between 8 and 14 K. The T = 0 Grüneisen parameter ?o = 2.58(±0.05) is in excellent agreement with the results obtained from high-pressure equation of state data.

J. C. Holste; C. A. Swenson

1975-01-01

201

Scintillation yield and time dependence from electronic and nuclear recoils in liquid neon  

NASA Astrophysics Data System (ADS)

We have performed measurements of scintillation light in liquid neon, observing a signal yield in our detector as high as (3.5 ± 0.4) photoelectrons/keV. We measure pulse shape discrimination efficiency between electronic and nuclear recoils in liquid neon from 50 to 300 keV nuclear recoil energy. We also measure the Leff parameter in liquid neon between 30 and 370 keV nuclear recoil energy, observing an average Leff=0.24 above 50 keV. We observe a dependence of the scintillation time distribution and signal yield on the pressure and temperature of the liquid neon.

Lippincott, W. H.; Coakley, K. J.; Gastler, D.; Kearns, E.; McKinsey, D. N.; Nikkel, J. A.

2012-07-01

202

On the mechanism of populating 3p levels of neon under pumping by a hard ioniser  

NASA Astrophysics Data System (ADS)

The effect of quenching additives on the luminescence properties of helium — neon mixtures under pumping by ? particles emitted from 210Po atoms is considered. It is concluded that, under excitation by a heavy charged particle, the population of the 3p'[1/2]0 level of neon is not related to the dissociative recombination of molecular ions. It is suggested that the most likely channels for populating the 3p level are the excitation transfer from metastable helium atoms to neon atoms and direct excitation of neon by nuclear particles and secondary electrons.

Khasenov, M. U.

2011-03-01

203

On the mechanism of populating 3p levels of neon under pumping by a hard ioniser  

SciTech Connect

The effect of quenching additives on the luminescence properties of helium - neon mixtures under pumping by {alpha} particles emitted from {sup 210}Po atoms is considered. It is concluded that, under excitation by a heavy charged particle, the population of the 3p'[1/2]{sub 0} level of neon is not related to the dissociative recombination of molecular ions. It is suggested that the most likely channels for populating the 3p level are the excitation transfer from metastable helium atoms to neon atoms and direct excitation of neon by nuclear particles and secondary electrons. (lasers and active media)

Khasenov, M U [Fotonika LLC, ul. Utegen batyra 112, 050062 Almaty (Kazakhstan)

2011-03-31

204

Helium-neon laser improves skin repair in rabbits.  

PubMed

The purpose of this study was to evaluate the influence of helium-neon laser on skin injury in rabbits. For this purpose, 15 New Zealand rabbits underwent bilateral skin damage in leg. Helium-neon laser light, at a fluence of 6?J?cm2 and wavelength of 632.8?nm, was applied on the left legs (laser group). The right leg lesions (control group) served as negative control. All sections were histopathologically analyzed using HE sections. The results showed little infiltration of inflammatory cells, with proliferation of fibroblasts forming a few fibrous connective tissue after 1 week post-injury. The lesion on the 3rd week was characterized by granulation tissue, which formed from proliferated fibrous connective tissue, congested blood vessels and mild mononuclear cell infiltration. On the 5th week, it was observed that debris material surrounded by a thick layer of connective tissue and dense collage, fibroblasts cells present in the dermis covered by a thick epidermal layer represented by keratinized epithelium. Taken together, our results suggest that helium-neon laser is able to improve skin repair in rabbits at early phases of recovery. PMID:23057697

Peccin, Maria Stella; Renno, Ana Claudia Muniz; de Oliveira, Flavia; Giusti, Paulo Ricardo; Ribeiro, Daniel Araki

2012-12-01

205

Rethermalizing collisions between magnetically trapped metastable neon atoms  

NASA Astrophysics Data System (ADS)

The successful Bose-Einstein Condensation (BEC) of alkali atoms has stimulated several groups to extend the range to metastable rare gas atoms. In 2001 this resulted in the achievement of BEC with metastable helium atoms (He^*) [1,2]. The only other rare gas atom suitable for achieving BEC is neon. The goal of our group is BEC of metastable neon (Ne^*). A condensate of metastable rare gas atoms is of special interest because their large internal energy enables real time diagnostics of the sample during condensation, giving new insight into the dynamics of the phase transition. Crucial for achieving BEC is a large (positive) scattering length. For He^* a good estimate of the order of magnitude of the scattering length was known. For neon no such theoretical estimate exists, therefore, experimental data on the value of the scattering length is necessary to determine whether or not BEC is feasible for Ne^*. In recent thermalization experiments involving two RF-knives, similar to the scheme used by Aspect et al. [3], we have observed rethermalizing collisions in our magnetic trap. Moreover, preliminary measurements point in the direction of a large absolute value of the scattering length. In this presentation we will discuss these thermalization experiments, and hope to present a value of the scattering length. [1] A. Robert et al., Science 292, 461 (2001). [2] F.P. Dos-Santos et al., Phys. Rev. Lett. 86, 3459 (2001). [3] A. Browaeys et al., Phys. Rev. A. 64, 034703 (2001).

Mogendorff, V. P.; Claessens, B. J.; Kuppens, S. J. M.; Vredenbregt, E. J. D.; Beijerinck, H. C. W.

2002-05-01

206

Sound radiation around a flying fly  

NASA Astrophysics Data System (ADS)

Many insects produce sounds during flight. These acoustic emissions result from the oscillation of the wings in air. To date, most studies have measured the frequency characteristics of flight sounds, leaving other acoustic characteristics-and their possible biological functions-unexplored. Here, using close-range acoustic recording, we describe both the directional radiation pattern and the detailed frequency composition of the sound produced by a tethered flying (Lucilia sericata). The flapping wings produce a sound wave consisting of a series of harmonics, the first harmonic occurring around 190 Hz. In the horizontal plane of the fly, the first harmonic shows a dipolelike amplitude distribution whereas the second harmonic shows a monopolelike radiation pattern. The first frequency component is dominant in front of the fly while the second harmonic is dominant at the sides. Sound with a broad frequency content, typical of that produced by wind, is also recorded at the back of the fly. This sound qualifies as pseudo-sound and results from the vortices generated during wing kinematics. Frequency and amplitude features may be used by flies in different behavioral contexts such as sexual communication, competitive communication, or navigation within the environment.

Sueur, Jérôme; Tuck, Elizabeth J.; Robert, Daniel

2005-07-01

207

Specific heats of solid natural neon at five molar volumes and of the separated neon isotopes at P =0  

Microsoft Academic Search

Direct measurements of the constant volume specific heatCvare reported for solid natural neon at several molar volumes (13.39–12.39 cm3\\/mole) at temperatures from 1 K to the melting line. All samples were solidified in a high-pressure bomb at the melting line (maximum conditions of 53 K and 2.5 kbar) and molar volumes for the melting line are given. The extrapolations of

R. Q. Fugate; C. A. Swenson

1973-01-01

208

Specific heats of solid natural neon at five molar volumes and of the separated neon isotopes at P=0  

Microsoft Academic Search

Direct measurements of the constant volume specific heat C v are reported for solid natural neon at several molar volumes (13.39 12.39 cm3\\/mole) at temperatures from 1 K to the melting line. All samples were solidified in a high-pressure bomb at the melting line (maximum conditions of 53 K and 2.5 kbar) and molar volumes for the melting line are

R. Q. Fugate; C. A. Swenson

1973-01-01

209

A determination of the neon isotopic composition of the mantle  

NASA Astrophysics Data System (ADS)

From the analysis of mantle-derived samples, several authors have proposed that the neon isotopic composition of the mantle was close to solar (21{Ne}/22{Ne}=13.8) (Marty, 1989, Honda et al., 1991), with additional nucleogenic 21{Ne} and possibly 22{Ne} due to Wethrlill reactions. This interpretation has been challenged by Trieloff et al. (2000; 2002) who claimed that the primitive mantle neon is different from solar wind Ne component and rather resembles to neon-B, a meteoritic Ne end-member. Trieloff's conclusion was based on the scarcity of precise data from plume-derived samples showing 20{Ne}/22{Ne} ratios higher than the Ne-B value of 12.5. A notable exception is the Kola carbonatite-ultramafic complex, Russia, has crystallized at depth, preventing extensive degassing and atmospheric contamination. (Marty et al., 1998). Here we report the results of a detailed study of separated mineral phases aimed to determine precisely the isotopic composition of the mantle neon. Mineral separate analysis showed that titano-magnetite in olivinite is the carrier of the highest 20{Ne}/22{Ne} component (12.82 ± 0.13 n=5, 1{?}). Statistical t-test indicates that titano-magnetite has a 21{Ne}/22{Ne} ratio higher than 12.6 at 95{%} confidence. Because such Ne still contains nucleogenic component, correction for this contribution results in a 20{Ne}/22{Ne} mantle end-member value definitely higher than 13. Such value for mantle neon supports direct incorporation of solar nebula gas rather than contribution of meteoritic solar component as a source volatile of the Earth and places constraint on the timing of accretional processes in the terrestrial region. B. Marty et al., EPSL 164, 179-192 (1998). M. Honda et al., Nature 349, 149-151 (1991). B. Marty., EPSL 94, 45-56 (1989). M. Trieloffet al., Science 288, 1036-1038 (2000). M. Trieloff et al., EPSL 200, 297-313 (2002).

Yokochi, R.; Marty, B.

2003-04-01

210

A Better Fly Trap  

NSDL National Science Digital Library

In this activity, learners observe fly behavior and then build a flytrap. They make more observations, compare the effectiveness of different traps, and modify their traps to increase their effectiveness. In doing so, learners consider what variables make for an effective trap as well as learning how to study the behavior of an animal. Even pesky flies provide an interesting challenge.

Science, Lawrence H.

1979-01-01

211

Liquid helium cryostat for SQUID-based MRI receivers  

Microsoft Academic Search

We describe a liquid helium cryostat, developed to cool SQUID-based receivers in low field MRI systems. The cryostat has a 4L liquid helium capacity, a hold time of over 3 days and accommodates 10cm diameter receiver coils. New vacuum insulation methods reduce the noise level by at least an order of magnitude compared to existing commercial designs. The minimum detectable

H. C. Seton; J. M. S. Hutchison; D. M. Bussell

2005-01-01

212

Quorum sensing in the squid-Vibrio symbiosis.  

PubMed

Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization. PMID:23965960

Verma, Subhash C; Miyashiro, Tim

2013-08-07

213

dc SQUIDs as linear displacement detectors for embedded micromechanical resonators  

NASA Astrophysics Data System (ADS)

Superconducting quantum interference devices (SQUIDs) can detect tiny amounts of magnetic flux and are also used to study macroscopic quantum effects. We employ a dc SQUID as a linear detector of the displacement of an embedded micromechanical resonator with a femtometer sensitivity. We discuss the measurement method, including operation in high magnetic field and a cryogenic amplification scheme which allows us to reach a resolution which is only a factor 4.4 above the standard quantum limit.RésuméLes magnétomètres à base de SQUID (Superconducting QUantum Interference Device) sont sensibles à de très faibles variations de flux magnétique et sont ainsi utilisés pour l'étude d'effets quantiques à l'échelle macroscopique. Nous avons réalisé une mesure linéaire du déplacement d'un microrésonateur mécanique enchâssé dans la boucle supraconductrice d'un dc SQUID. En utilisant un fort champ magnétique et un amplificateur fonctionnant en régime cryogénique, cette méthode de mesure nous a permis d'atteindre une résolution qui n'est que 4,4 fois la limite quantique.

Etaki, Samir; Poot, Menno; Onomitsu, Koji; Yamaguchi, Hiroshi; van der Zant, Herre S. J.

2011-12-01

214

A high-resolution, SQUID-based vibrating coil susceptometer  

NASA Astrophysics Data System (ADS)

A superconducting quantum interference device (SQUID) plays an important role in the development of ultrasensitive electric and magnetic measurement systems. SQUID instrumentation offers diversified applications with its ability to make measurements where other methodologies could not be applied. A high sensitivity magnetic measurement technique to measure the magnetic susceptibility of extremely small volume samples using a SQUID vibrating coil magnetometer (SVCM) has been developed. In this setup, position differentiating detection (PDD) of magnetic flux from the sample has been coupled with the SQUID magnetometer. The sensitivity of the setup depends on the vibrating amplitude of the pick-up coil. The pick-up coil of the SVCM has been steadily vibrated with a maximum amplitude of 75 µm close to the sample at the resonant frequency using bimorph piezoelectric bender type actuators. An equivalent circuit model for the piezoelectric actuator has been constructed, and its resonance frequency has also been cross-checked by simulation software. The vibration of actuators for a wide range of temperatures (4.2 K-300 K) has been controlled by a negative feedback circuit. The detailed design, construction and performance of the SVCM have been described.

Manivannan, N.; Arumugam, S.; Kasthurirengan, S.; Anand, N. B.

2008-12-01

215

Timing of squid migration reflects North Atlantic climate variability  

Microsoft Academic Search

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 south-west England over a 19-year period. We show that

David W. Sims; Martin J. Genner; Alan J. Southward; Stephen J. Hawkins

2001-01-01

216

Liquid Junction and Membrane Potentials of the Squid Giant Axon  

Microsoft Academic Search

The potential differences across the squid giant axon membrane, as measured with a series of microcapillary electrodes filled with concentrations of KCI from 0.03 to 3.0 M or sea water, are consistent with a constant mem- brane potential and the liquid junction potentials calculated by the Hender- son equation. The best value for the mobility of an organic univalent ion,

KENNETH S. COLE; JOHN W. MOORE

2009-01-01

217

Experimental Jigging for Squid off the Northeast United States.  

National Technical Information Service (NTIS)

Illex illecebrosus is very agressive and exhibits an attractive taxis toward light which lends very well to night light jigging. Squid jigging is a fishing technique that is relatively simple in operation when compared with a trawl fishery. Since the jigg...

D. Long W. F. Rathjen

1980-01-01

218

Detection of Zooplankton Prey in Squid Paralarvae with Immunoassay  

Microsoft Academic Search

Sustainable management of economically important squid requires monitoring of changes in their abundance, which are related inter alia, to their success in the food chain. the highest mortality is expected in the paralarval stages, which are prone to starvation. Causes of starvation may be linked to the lack of suitable prey. A multiple detection system was developed for the simultaneous

J. D. Venter; S. van Wyngaardt; J. A. Verschoor; M. R. Lipi?ski; H. M. Verheye

1999-01-01

219

A Numerical Treatment of the Rf SQUID: II. Noise Temperature  

SciTech Connect

We investigate rf SQUIDs (Superconducting QUantum Interference Devices), coupled to a resonant input circuit, a readout tank circuit and a preamplifier, by numerically solving the corresponding Langevin equations and optimizing model parameters with respect to noise temperature. We also give approximate analytic solutions for the noise temperature, which we reduce to parameters of the SQUID and the tank circuit in the absence of the input circuit. The analytic solutions agree with numerical simulations of the full circuit to within 10%, and are similar to expressions used to calculate the noise temperature of dc SQUIDs. The best device performance is obtained when {beta}{sub L}{prime} {triple_bond} 2{pi}LI{sub 0}/{Phi}{sub 0} is 0.6-0.8; L is the SQUID inductance, I{sub 0} the junction critical current and F{sub 0} the flux quantum. For a tuned input circuit we find an optimal noise temperature T{sub N,opt} {approx} 3Tf/f{sub c}, where T, f and f{sub c} denote temperature, signal frequency and junction characteristic frequency, respectively. This value is only a factor of 2 larger than the optimal noise temperatures obtained by approximate analytic theories carried out previously in the limit {beta}{sub L}{prime} << 1. We study the dependence of the noise temperature on various model parameters, and give examples using realistic device parameters of the extent to which the intrinsic noise temperature can be realized experimentally.

Kleiner, Reinhold; Koelle, Dieter; Clarke, John

2007-01-15

220

Integrated low-temperature superconductor SQUID gradiometers for nondestructive evaluation  

Microsoft Academic Search

We describe an eddy current nondestructive evaluation system using a low-temperature superconductor magnetic field sensor in an electromagnetically unshielded environment. The sensor comprises a niobium dc superconducting quantum interference device (SQUID) integrated with a first-order gradiometric pickup coil to reject spatially uniform interference fields but remain sensitive to flaw induced fields. We demonstrate its use in locating and mapping subsurface

Uho Klein; Morag E. Walker; Chris Carr; D. M. McKirdy; C. M. Pegrum; G. B. Donaldson; A. Cochran; H. Nakane

1997-01-01

221

Cloning and biochemical characterization of astacin-like squid metalloprotease.  

PubMed

We have cloned four cDNAs encoding astacin-like squid metalloproteases (ALSMs)-I and -II from the Japanese common squid and ALSMs-I and -III from the spear squid. Analysis of the deduced amino acid sequences revealed that ALSMs possess a signal peptide and a pro-sequence followed by an astacin-like catalytic domain and an MAM (meprin, A5 protein, receptor protein-tyrosine phosphatase mu) domain. Phylogenetic analysis revealed that ALSM corresponds to a new cluster of astacins. To analyze the function of the MAM domain, wild-type ALSM and an MAM-truncated mutant were expressed in a baculovirus expression system. The expressed protein encoding full-length ALSM hydrolyzed myosin heavy chain as effectively as native ALSM, whereas the MAM-truncated mutant possessed no protease activity, suggesting that the MAM domain contributes to substrate recognition. ALSM has been isolated from squid liver and mantle muscle. However, analysis with a specific antibody generated against ALSM indicated the presence of ALSM in a wide variety of tissues. ALSM was located in the extracellular matrix of mantle muscle cells. Thus, ALSM is a secreted protease, as are other members of the astacin family. The extracellular localization raises the possibility of substrates other than myosin. The physiological role of ALSM remains unknown, at this time. PMID:12417025

Yokozawa, Yuya; Tamai, Hitomi; Tatewaki, Shuntaro; Tajima, Takaho; Tsuchiya, Takahide; Kanzawa, Nobuyuki

2002-11-01

222

Macroscopic quantum tunneling in a dc SQUID: Instanton splitting  

Microsoft Academic Search

The theory of macroscopic quantum tunneling is applied to a current-biased dc SQUID which constitutes a system of two interacting quantum degrees of freedom coupled to the environment. The decay probability is obtained in the exponential approximation for the overdamped case. Close to the critical driving force of the system, the decay of the metastable state is determined by a

C. Morais Smith; B. Ivlev; G. Blatter

1994-01-01

223

A technique to demonstrate energy level quantization in a SQUID  

Microsoft Academic Search

An integrated circuit has been designed to investigate the quantization of energy levels in an RF SQUID. The experiment is very similar to the rapid-sweep technique of Silvestrini et al., except that it is accomplished by using superconducting digital electronic circuitry as the experimental apparatus. This allows the system being studied to be very well isolated from its environment.

Marc J Feldman

2000-01-01

224

FlyNome  

NSDL National Science Digital Library

FlyNome is the brainchild of _Drosophila_ researcher, Christopher Yohn, of the Skirball Institute in New York City. Yohn created this Web site out of the frustration involved in trying to find the stories behind the names of fruit fly genes. New to the Scout Report, FlyNome "is intended to be a resource for the _Drosophila_ community by serving as a reliable tool to which fly researchers can refer and contribute." Users may search the database by gene symbol, full gene name, name of contributor, or simply browse all entries. FlyNome will also track down stories (by request) for genes not currently in the database. The site also includes useful Web links and a FAQ page.

225

SQUID Microscopy: Magnetic Images of Room Temperature Samples  

NASA Astrophysics Data System (ADS)

We use a microscope based on a high-Tc Superconducting Quantum Interference Device (SQUID) to study room temperature samples. The SQUID, which measures magnetic flux, is mounted on a sapphire rod and maintained at 77 K inside a vacuum chamber. A sample, separated from the vacuum chamber by a window, is placed above the SQUID, and the entire microscope is enclosed within a magnetic shield. The sample can be scanned over the SQUID to obtain a magnetic image. We have used the microscope to study magnetotactic bacteria, which have a permanent magnetic dipole moment of about 1.5 x 10-16 Am^2. The bacteria, suspended in an aqueous medium, are placed in a cell which is separated from the vacuum chamber by a 3 micron thick SiN membrane. The sample is brought as close as 15 micron to the SQUID, and the magnetic flux noise from the motion of the bacteria is measured. Data from non-motile cells, which undergo Brownian motion, give us information about the distribution of lengths of the bacteria. By applying a magnetic field, we can determine the average dipole moment. Noise measurements of the live bacteria give us the rates of flagellar rotation and body-roll, as well as the amplitudes of the vibrational and precessional motions. Another application of the microscope is non-destructive evaluation of steel. We have investigated the effects of both thermal and mechanical stresses on the remnant magnetization of steel. A third application of the microscope is in studying the properties of ferromagnetic nanocrystals of Co and Fe_3O_4.

Grossman, Helene

1998-10-01

226

Dichroism in the above-threshold two-colour photoionization of singly charged neon  

Microsoft Academic Search

In this work we report on the ionization of a gaseous neon target by combining extreme ultraviolet (XUV) radiation from the Free Electron Laser in Hamburg with an intense synchronized optical laser. Applying energy-resolved photoelectron spectroscopy, the dependence of the electrons ejected from singly charged neon (Ne+) on the relative polarization of the XUV and optical laser fields was investigated.

V Richardson; W B Li; T J Kelly; J T Costello; L A A Nikolopoulos; S Düsterer; D Cubaynes; M Meyer

2012-01-01

227

Interactions of 10.5 Gev/C Pions with Neon Nuclei.  

National Technical Information Service (NTIS)

The interactions of 10.5-GeV/c pions with neon nuclei were studied and compared with pi p interactions. The average number of charged pions from neon interactions is 3.45 +- .03; of nucleons, 4.45 +- .13. The charged pion multiplicity distribution for neo...

W. M. Yeager

1976-01-01

228

Mass transfer of helium, neon, argon, and xenon through a steady-state upper mantle  

Microsoft Academic Search

We have examined the steady-state upper mantle model for helium, neon, argon, and xenon following the mass transfer approach presented by Kellogg and Wasserburg (1990) for helium and Porcelli and Wasserburg (1995a) for xenon. The model explains the available observational data of mantle helium, neon, argon, and xenon isotope compositions and provides specific predictions regarding the rare gas isotopic compositions

D. Porcelli; G. J. Wasserburg

1995-01-01

229

The solubility of neon, nitrogen and argon in distilled water and seawater  

Microsoft Academic Search

Large discrepancies in published neon and nitrogen solubility data limit the interpretation of oceanic measurements of these gases. We present new solubility measurements for neon, nitrogen and argon in distilled water and seawater, over a temperature range of 1–30?C. Water was equilibrated with air at measured temperatures, salinities and pressures. Dissolved Ne concentrations were then determined by isotope dilution using

Roberta C. Hamme; Steven R. Emerson

2004-01-01

230

Helium, neon, argon, krypton and xenon in gas emanations from Yellowstone and Lassen volcanic National Parks  

Microsoft Academic Search

The abundance of helium, neon, argon, krypton and xenon were measured in gas emanations from thermal springs in Yellowstone National Park, Wyoming and Lassen National Park, California. The determinations were made using an isotope dilution procedure. The isotopic composition of argon and the relative abundances of argon, neon, krypton and xenon indicate that these gases originated from the atmosphere through

E. Mazor; G. J. Wasserburg

1965-01-01

231

Using NEON to Measure Adaptation of Vegetation to Changes in Environmental Forcing  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is a national-scale research platform for documenting and analyzing the impacts of climate change, land-use change, and invasive species on ecology. NEON features sensor networks and experiments linked by cyberinfrastructure to record and archive ecological data for at least 30 years. NEON partitions the United States into 20 ecoclimatic domains. Each domain hosts one fully instrumented core site in a wildland area and two re-locatable sites, which aims to capture ecologically significant gradients (e.g. landuse). Using standardized protocols and an open data policy, NEON data will be gathered from the level of the gene and organism to populations and communities, with extrapolations to the continental scale. In conjunction with environmental data, NEON will conduct field observations and analyses of biological specimens to track biodiversity, population dynamics, productivity, phenology, infectious disease, biogeochemistry and ecohydrology. Here we present a few examples of the type of research NEON will enable using this data. The NEON network will measure and scale many environmental factors that affect vegetation, e.g. temperature, precipitation, and nutrient availability. Direct monitoring of vegetation will enable the study of acclimatory and adaptive changes in vegetation properties over different time scales. Such data will improve the representation of vegetation responses to environmental change in models. The vision behind NEON aims to advance our ability to quantitatively predict ecological change.

Martin, P. H.; Kao, R.; Gibson, C.

2009-12-01

232

Ionized Neon Spectral Lines Stark Widths for Stellar Plasma Research and Modeling  

Microsoft Academic Search

Neon is the most abundant element in the Universe after H, He, O and C and it is one of products of hydrogen and helium burning in orderly evolution of stellar interiors. After hydrogen, helium and carbon burning periodes in massive stars starts neon burning. Stark broadening parameters of Ne II spectral lines are of importance in astrophysics for a

Milan S. Dimitrijevic; Vladimir Milosavljevic; Stevan Djeniz

2001-01-01

233

Mantle deformation and noble gases: Helium and neon in oceanic mylonites  

Microsoft Academic Search

In an effort to constrain the behavior of noble gases during mantle deformation, we present new helium and neon data in mylonites from subaerial St. Peter and St. Paul Archipelago (Mid-Atlantic Ridge) and the submarine Southwest Indian Ridge. Coupled vacuum crushing and melting experiments show that most of the helium and neon within the mylonites is contained in the mineral

Mark D. Kurz; Jessica M. Warren; Joshua Curtice

2009-01-01

234

Solar abundances of oxygen and neon derived from solar wind observations  

Microsoft Academic Search

Context: Recently, a revision of the solar abundances of C, N, and O to substantially lower values has led to a controversy on solar opacities in the solar standard model and to the suggestion to revise the solar abundance of neon upward by as much as a factor of 1.6 leading to enhanced solar neon\\/oxygen abundance ratios by a factor

P. Bochsler

2007-01-01

235

Experimental Investigation of the Electrical and Optical Characteristics of an Inductively Coupled Discharge in Neon  

Microsoft Academic Search

An experimental investigation of the electrical and optical characteristics of an inductively coupled discharge in neon is performed in a wide range of conditions of discharge burning, namely, discharge tube diameters of 20, 34, and 58 mm, neon pressures of 10 to 600 Pa, discharge currents of 1 to 30 A, and current frequencies of 25 and 250 kHz. The

M. V. Isupov; I. M. Ulanov; A. Yu. Litvintsev

2004-01-01

236

Analysis of the parameters of plasma of an inductively coupled discharge in neon  

Microsoft Academic Search

An experimental investigation is performed of the electrical and spectral characteristics of plasma of an electrodeless neon light source operating on the principle of inductively coupled discharge. The investigations are performed under the optimal conditions of discharge burning (neon pressure of ˜1 torr, current frequency of 250 kHz, and discharge current of 3 to 10 A) corresponding to the high

M. V. Isupov; I. M. Ulanov

2005-01-01

237

How Things Fly  

NSDL National Science Digital Library

Provided by the National Air and Space Museum, this site allows users to visit the special exhibit How Things Fly. In How Do Things Fly? the following topics are discussed in a question and answer format: Can you fly?, Air is "stuff"!, Balloons, Animal flight, Airplanes, and Spacecraft. The physics behind flight for each topic is at a general level, making this site an excellent source for K-12 education. Specific science activities, along with recommended reading, are found in the Resource Center. Additional links contain interesting comments and activities for particular topics.

1999-01-01

238

Fruit Fly Phlebotomy  

NSDL National Science Digital Library

The tiny fruit fly is a popular guinea pig for genetic research but just try strapping one of them down for a blood sample. Until now, researchers have had to squeeze dozens of flies at once to get enough blood to study. But now, scientists at the University of Illinois at Chicago have extracted blood from a single fruit fly larva, collecting as little as 50 billionths of a liter with an ultra-thin vacuum tube. Analytical chemist Scott Shippy says the technique could help scientists study human tissue as well, like the retinal cells in the eye.

Science Update (AAAS;)

2008-04-21

239

Adsorption of nitrogen, argon, and neon on sintered copper and of neon on argon-coated sintered copper at low temperatures  

Microsoft Academic Search

The results of measurements of adsorption isotherms are given for nitrogen, argon, and neon on bare sintered copper and on sintered copper covered with a monolayer of argon. The temperatures employed where 77.3 K for the N2 and argon, and 17.26, 20.22, 22.64, 25.71, and 27.00 K for the neon, and the pressure range was from 0.25 to 200 Torr.

E. Lerner; J. G. Daunt

1972-01-01

240

Nonlinear dynamics modulation in a neon glow discharge plasma  

NASA Astrophysics Data System (ADS)

In dynamics modulation, two modes in a driven neon glow discharge alternate as the dominant mode as their response to the driving force alternates between spatiotemporal and temporal periodic pulling. This phenomenon was first noted by Koepke, Weltmann, and Selcher (Bull. Am. Phys. Soc. 40, 1716 (1995)), who saw two limited but representative cases and proposed a mechanism (Phys. Rev. E 62, 2773 (2000)) by which it occurs. The intent of this dissertation is to document experimentally and test the dynamics modulation mechanism they proposed. Using a new extension of a previous mathematical treatment of periodic pulling, the resulting experimental data are used to verify the predicted mechanism. A numerical model is also presented that reproduces the signature of dynamics modulation and further supports the validity of the mechanism. For two pairs of mode frequencies, three complete data series as driving frequency is increased are presented. Each of these data series shows the progression of the system from pure spatiotemporal behavior, through dynamics modulation, and ending at entrainment in the upper mode. Ionization wave modes are examined using time series recorded using a photodiode with a narrow band filter that selectively passes the primary neon spectral line at 640 nm. The system was periodically driven using a narrow-band ring dye laser tuned to a wavelength near the metastable neon transition at 588.35 nm. The amplitude of the driving force was decreased (increased) by tuning the laser away from (nearer to) the center of the neon line, while the driving frequency was controlled by an acousto-optic modulator chopping the laser beam at the desired frequency. Arnol'd tongue boundaries identifying the edges of frequency entrainment regions in the driving amplitude-driving frequency plane were established for four different discharge currents. The (upward) dynamics modulation behavior seen by Koepke, Weltmann, and Selcher was reproduced and additional data were acquired for two additional representative cases of downward modulations, previously undocumented. The upward modulations are used to verify the mechanism, while the downward modulations exhibit qualitatively different behavior. These differences are discussed. Two coupled van der Pol equations were chosen to model the mechanism described by Koepke, Weltmann, and Selcher, and the resulting time series was solved with a Runge-Kutta routine whose parameters could be adjusted as the simulation proceeded. The model successfully reproduces the qualitative behavior of dynamics modulation and reinforces the experimental verification of the proposed mechanism, but lacks sufficient complexity for a complete quantitative comparison.

Miller, Paul M.

241

Multiply charged neon clusters: failure of the liquid drop model?  

PubMed

We have analyzed the stability and fission dynamics of multiply charged neon cluster ions. The critical sizes for the observation of long-lived ions are n2=284 and n3=656 for charge states 2 and 3, respectively, a factor 3 to 4 below the predictions of a previously successful liquid-drop model. The preferred fragment ions of fission reactions are surprisingly small (2

Mähr, I; Zappa, F; Denifl, S; Kubala, D; Echt, O; Märk, T D; Scheier, P

2007-01-08

242

Fluorescence of protonated pyrene and coronene in neon matrices  

NASA Astrophysics Data System (ADS)

Fluorescence spectra of protonated pyrene and coronene in solid neon have been observed. Laser excitation of the Sn ? S0 transitions of the cations results in an extended, vibrationally-resolved S1 ? S0 fluorescence with onset at 487.8 and 695.4 nm for protonated pyrene and coronene, respectively. Vibrational assignment of the spectra has been made on the basis of the calculated frequencies of normal modes in the ground electronic state. The astrophysical relevance of the frequencies inferred for these protonated cations is discussed.

Garkusha, Iryna; Fulara, Jan; Maier, John P.

2012-10-01

243

Nuclear quantum effects on the stability of cationic neon clusters  

NASA Astrophysics Data System (ADS)

The stable structures of cationic neon clusters containing up to 57 atoms have been located using a diatomic-in-molecules potential energy surface and basin-hopping hierarchical optimization. The effects of vibrational delocalization were included either in the harmonic approximation, or by performing Langevin molecular dynamics simulations coupled to a quantum thermal bath at T=0. For most clusters, zero-point motion is sufficiently high to blur the picture of a single well-defined structure. However, structural diversity of the ground state wavefunction is found to be lower at sizes 14, 21, and 56, which correspond to special stabilities in experimental mass spectra.

Calvo, F.; Naumkin, F. Y.; Wales, D. J.

2012-11-01

244

What Is The Neon Abundance Of The Sun?  

Microsoft Academic Search

We have evolved a series of thirteen complete solar models that utilize\\u000adifferent assumed heavy element compositions. Models that are based upon the\\u000aheavy element abundances recently determined by Asplund, Grevesse, and Sauval\\u000a(2005) are inconsistent with helioseismological measurements. However, models\\u000ain which the neon abundance is increased by 0.4-0.5 dex to log N(Ne) = 8.29 +-\\u000a0.05 (on the

John N. Bahcall; Sarbani Basu; Aldo M. Serenelli

2005-01-01

245

Neon Isotope and Lambda Hypernuclei with the Nijmegen Hyperon Interaction  

NASA Astrophysics Data System (ADS)

We optimize the nuclear parameterization for the description of Ne isotope in the deformed Skyrme-Hartree-Fock model, and succeed in providing an overall good description of the nuclear deformation in this model, which is consistent with the available experimental data and microscopic model results. The addition of a ? hyperon, based on a realistic Nijmegen hyperon-nucleon potential, is found to have no large effect on the shape of the isotopic nuclei, indicating that the neon isotopic nuclei might not be good candidates for studying the deformation effect of hyperon in future experiments.

Li, A.

2013-08-01

246

Ommatidia of blow fly, house fly, and flesh fly: implication of their vision efficiency  

Microsoft Academic Search

This work aims to elucidate the number of ommatidia or facets (the outwardly visible units of each ommatidium) for compound\\u000a eyes in blow flies [Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart), Chrysomya nigripes (Aubertin), Lucilia cuprina (Wiedemann)], house flies (Musca domestica L.), and flesh flies (Liosarcophaga dux Thomson) by manual counts of the corneal spreads. The head of the fly in

Kabkaew L. Sukontason; Tarinee Chaiwong; Somsak Piangjai; Sorawit Upakut; Kittikhun Moophayak; Kom Sukontason

2008-01-01

247

Muscoid-fly Octosporeosis.  

National Technical Information Service (NTIS)

The objective of the project is to gather information on Octosporea muscaedomesticae (Protozoa: Microsporidia), the causative agent of an intestinal octosporeosis in muscoid flies. How this agent might be manipulated in the applied biological control of n...

J. P. Kramer

1972-01-01

248

Powered Parachute Flying Handbook.  

National Technical Information Service (NTIS)

The Powered Parachute Flying Handbook is designed as a technical manual for applicants who are preparing for a powered parachute category rating and for currently certificated powered parachute pilots who wish to improve their knowledge. Certificated flig...

2007-01-01

249

Evaluation of a pulse-discharge helium ionisation detector for the determination of neon concentrations by gas chromatography.  

PubMed

A pulse-discharge helium ionisation detector, PDHID (Valco, PD-D2-I) with sample introduced to the discharge zone is shown to be applicable for reliable determinations of neon by gas chromatography. The detection level of 80 pg was obtained, but the dependence between detector response and neon mass was non-linear. However, for the discharge gas doped with 33 ppm of neon, a linear response to the neon mass up to 10(-5) g and the detection level of 0.5 ng were obtained. The method can be used for measuring neon concentrations in groundwater systems for hydrogeological purposes. PMID:15124819

Lasa, J; Mochalski, P; Pusz, J

2004-05-01

250

Design a Flying Machine  

NSDL National Science Digital Library

The purpose of this activity is for the students to draw a design for their own flying machine. They will apply their knowledge of aircraft design and the forces acting on them. The students will start with a brainstorming activity where they come up with creative uses for every day objects. They will then use their creativity and knowledge of airplanes to design their own flying machine.

Integrated Teaching And Learning Program

251

Selenium in fly ash.  

PubMed

Selenium, at concentrations exceeding 200 parts per million (ppm) (dry weight), has been found in white sweet clover voluntarily growing on beds of fly ash in central New York State. Guinea pigs fed such clover concentrated selenium in their tissues. The contents of the honey stomachs of bees foraging on this seleniferous clover contained negligible selenium. Mature vegetables cultured on 10 percent (by weight) fly ash-amended soil absorbed up to 1 ppm of selenium. Fly ashes from 21 states contained total selenium contents ranging from 1.2 to 16.5 ppm. Cabbage grown on soil containing 10 percent (by weight) of these fly ashes absorbed selenium (up to 3.7 ppm) in direct proportion (correlation coefficient r = .89) to the selenium concentration in the respective fly ash. Water, aquatic weeds, algae, dragonfly nymphs, polliwogs, and tissues of bullheads and muskrats from a fly ash-contaminated pond contained concentrations of selenium markedly elevated over those of controls. PMID:1251212

Gutenmann, W H; Bache, C A; Youngs, W D; Lisk, D J

1976-03-01

252

Plastic-molded LTS DC-SQUIDs for multichannel biomagnetic measurement systems  

Microsoft Academic Search

A plastic molding technique for SQUIDs has been developed to protect the chip from moisture damage. A 1.5-mm-thick layer of molding compound (epoxy resin, elastic resin, and silica powder) was poured over Ketchen-type DC-SQUID that has Nb\\/AlOx\\/Nb Josephson junctions. The moisture resistance of these plastic-molded SQUIDs was examined by subjecting them to temperature and humidity storage tests (60°C, 90% relative

Yukihiro Utaka; T. Kido; K. Kudo

1997-01-01

253

High T c SQUIDs: the ultra sensitive sensors for non-destructive testing and biomagnetism  

Microsoft Academic Search

This paper reviews the theory and applications of SQUID magnetometers, in view of recent progress in SQUID technology and since the discovery of high-Tc superconductors (HTS). With their unrivalled sensitivity for magnetic flux and, consequently, for magnetic fields, voltages and currents, SQUID magnetometers have succeeded in a variety of applications, particularly in fields where a non-invasive, non-destructive type of detection

A. E. Mahdi; D. J. Mapps

2000-01-01

254

The trophic link between squid and the emperor penguin Aptenodytes forsteri at Pointe Géologie, Antarctica  

Microsoft Academic Search

Cephalopod beaks retrieved from stomachs of dead emperor penguin chicks at Pointe Géologie, Terre Adélie, provide information\\u000a on taxonomic and size composition of the penguin’s squid diet, on the trophic range of the squid species preyed upon and on\\u000a the fractional trophic impact of the penguin on the whole food web. Emperor penguins prey upon four squid species (Psychroteuthis glacialis,

Ilka Zimmer; Uwe Piatkowski; Thomas Brey

2007-01-01

255

Investigation of Low-Frequency Excess Flux Noise in DC SQUIDs at mK Temperatures  

Microsoft Academic Search

The excess low-frequency flux noise in dc super- conducting quantum interference devices (SQUIDs) operated at ultra-low temperatures was studied. A large number of single SQUIDs as well as SQUID arrays from 16 wafers fabricated over a period of six years were characterized at 4.2 K and 320 mK. Considering the large spread in the low-frequency noise at 4.2 K, there

Dietmar Drung; Jörn Beyer; Jan-Hendrik Storm; Margret Peters; Thomas Schurig

2011-01-01

256

Cooling performance of hybrid refrigerant of solid nitrogen and small amount of neon for the purpose of HTS power applications  

NASA Astrophysics Data System (ADS)

We have investigated cooling performance of a hybrid refrigerant of solid nitrogen and small amount of neon by using a short sample of Bi-2223/Ag tape as a cooling target. Solid nitrogen is expected as a heat capacitor for HTS applications operated below triple point temperature of nitrogen, and we have proposed in our previous study a method for overcoming the problem of its thermal contact with a cooling target with the aid of small amount of liquid neon. This paper discusses the phase state as well as the quantity of neon required for such an improvement. Nitrogen gas was introduced into a sample chamber through a mass flow controller, and then was liquefied and solidified by a Gifford-McMahon cryocooler. After that, in order to improve thermal contact of the solid nitrogen with the sample, neon gas was also introduced into the chamber at 25 K where neon can be liquefied. Cooling performance of such a hybrid refrigerant with different inputs of neon was evaluated by measuring temperature rise of the sample with the transportation of overcurrent. As a result, neon could suppress the temperature rise even in gas state, and the existence of liquid neon could additionally suppress the temperature rise. Furthermore, the required proportion of the liquid neon to the solid nitrogen was very small. From these results, we concluded that introducing neon until neon can be liquefied was the best way to make the most of the potential of the hybrid refrigerant.

Higashikawa, K.; Nakamura, T.

2009-11-01

257

Liquid helium cryostat for SQUID-based MRI receivers  

NASA Astrophysics Data System (ADS)

We describe a liquid helium cryostat, developed to cool SQUID-based receivers in low field MRI systems. The cryostat has a 4 L liquid helium capacity, a hold time of over 3 days and accommodates 10 cm diameter receiver coils. New vacuum insulation methods reduce the noise level by at least an order of magnitude compared to existing commercial designs. The minimum detectable field at 425 kHz, with a 5 cm diameter circular coil, was estimated to be 0.018 fT/Hz1/2 from Q-factor measurements and 0.035 fT/Hz1/2 by direct measurement with a SQUID amplifier. Further measurements indicated that most of this field noise probably originates with dielectric losses in the cryostat’s fibreglass shells.

Seton, H. C.; Hutchison, J. M. S.; Bussell, D. M.

2005-05-01

258

Establishment of 37 channel SQUID system for magnetocardiography  

NASA Astrophysics Data System (ADS)

We report the development of a thirty seven channel SQUID based Magnetocardiography (MCG) system for the measurement of biomagnetic fields originating from the human heart. These fields are extremely weak and can be non-invasively measured only by using SQUID sensors. The system can simultaneously record biomagnetic signals at thirty seven spatial locations on the chest with a total coverage area of 300 cm2. The typical noise level of the system is measured to be about 2.5 fTrms/cm/?Hz for most gradiometer channels and around 7.3 fTrms/?Hz for magnetometer channels. The measurement of Magnetocardiogram (MCG) from human heart carried out using this system is shown.

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

2012-06-01

259

Low-frequency Flux Noise in SQUIDs and Superconducting Qubits  

NASA Astrophysics Data System (ADS)

Superconducting qubits are a leading candidate for scalable quantum information processing. In order to realize the full potential of these qubits, it is necessary to develop a more complete understanding of the microscopic physics that governs dissipation and dephasing of the quantum state. In the case of the Josephson phase and flux qubits, the dominant dephasing mechanism is an apparent low-frequency magnetic flux noise with a 1/f spectrum. The origin of this excess noise is not understood. We report the results of SQUID measurements that explore the dependence of the excess low-frequency flux noise on SQUID inductance, geometry, materials, and temperature. We discuss contributions to the measured noise from temperature fluctuations, trapped vortices in the superconducting films, and surface magnetic states in the native oxides of the superconductors. We discuss implications of our measurements for qubit dephasing.

Sendelbach, Steven; Hover, David; Kittel, Achim; Mueck, Michael; McDermott, Robert

2008-03-01

260

Hysteresis in superconducting short weak links and ? -SQUIDs  

NASA Astrophysics Data System (ADS)

Thermal hysteresis in a micron-size superconducting quantum interference device ( ? -SQUID), with weak links as Josephson junctions, is an obstacle for improving its performance for magnetometry. Following the “hot-spot” model of Skocpol [J. Appl. Phys. 45, 4054 (1974)]10.1063/1.1663912 and by incorporating the temperature dependence of the superconductor thermal conductivity under a linear approximation, we find a much better agreement with the observed temperature dependence of the retrapping current in short superconducting Nb-based weak links and ? -SQUIDs. In addition, using the temperature dependence of the critical current, we find that above a certain temperature hysteresis disappears. We analyze the current-voltage characteristics and the weak link temperature variation in both the hysteretic and nonhysteretic regimes. We also discuss the effect of the weak link geometry in order to widen the temperature range of hysteresis-free operation.

Hazra, Dibyendu; Pascal, Lætitia M. A.; Courtois, Hervé; Gupta, Anjan K.

2010-11-01

261

Optimizing the Gain and Noise Temperature of Microstrip SQUID Amplifiers  

NASA Astrophysics Data System (ADS)

Micrrostrip SQUID amplifiers (MSA) offer near quantum-limited sensitivity and gains greater than 20 dB at frequencies around 1 GHz. These properties make them desirable for applications ranging from dark-matter axion detection to dispersive readout of superconducting qubits. The input of the MSA is a microstrip transmission line in the shape of a square spiral coil surrounding the hole in the SQUID washer that serves as the ground plane. Near the fundamental resonance, there is strong flux coupling between the input coil and SQUID. To obtain maximum performance it is necessary to know the complete set of complex scattering parameters. We present measurements of the scattering parameters of MSAs cooled to 4.2 K. The input impedance is found by measuring the reverse scattering parameter (S11) and is described well by a low-loss transmission line model. We map the low-loss transmission line model into an equivalent parallel RLC circuit that accurately predicts the observed gain given by the forward scattering parameter (S21). This information is used to optimize the input and output matching circuitry to achieve optimal noise temperature and gain. We will present results for the gain, dynamic range, linearity and noise temperature of these optimized MSAs at 30-500 mK as a function of frequency and SQUID bias. We will compare the results to the prediction of the circuit model and to the theoretical expectation that the lowest noise temperature occurs off-resonance. This work is in collaboration with John Clarke and a portion of this work was supported by DOE.

Kinion, Darin

2009-03-01

262

Experimental Pair Trawling for Squid in New England  

Microsoft Academic Search

were chartered by the New England Fisheries Development Program (NEFDP) to fish up to 12 days in Nan­ tucket Sound during the spawning sea­ son when squid are inshore in shoal water. They were the 85-foot (26-m) Karen Sue with 300 hp and the 57-foot (17.4-m) Susan and Lori with 335 hp. A fisheries engineer from the Glouces­ ter Laboratory

ALAN J. BLOTT

263

Actin-dependent organelle movement in squid axoplasm  

Microsoft Academic Search

STUDIES of organelle movement in axoplasm extruded from the squid giant axon have led to the basic discoveries of microtubule-dependent organelle motility1-3 and the characterization of the microtubule-based motor proteins kinesin and cytoplasmic dynein4,5. Rapid organelle movement in higher animal cells, especially in ,neurons, is considered to be microtubule-based. The role of actin filaments, which are also abundant in axonal

Sergei A. Kuznetsov; George M. Langford; Dieter G. Weiss

1992-01-01

264

Detecting damage in steel with scanning SQUID microscopy  

SciTech Connect

A ''Holy Grail'' of NDE research is a non-destructive method for measuring fatigue damage prior to crack initiation. High-Tc scanning SQUID microscopy may be a useful tool. Because of the exceptional magnetic sensitivity of this technique, fatigue damage can be detected well before microcrack initiation, and in the absence of other obvious microstructure or property changes. Given the spatial resolution of the technique, undamaged material can be located and used to set internal standards.

Lee, Tae-Kyu; Clatterbuck, David; Morris Jr., J.W.; Shaw, T.J.; McDermott R.; Clarke, John

2001-09-04

265

LTS SQUID gradiometer system for in vivo magnetorelaxometry  

Microsoft Academic Search

A system for spatially resolved magnetorelaxometry in spatially expanded objects (e.g. for in vivo investigations) in a disturbed environment is presented. The system is based on an LTS SQUID gradiometer with a field gradient sensitivity of 30 fT cm-1 Hz-1\\/2 and an intrinsic balance of some 10-5. A Helmholtz coil of 80 cm diameter allows the magnetization of the samples

L. Warzemann; J. Schambach; P. Weber; W. Weitschies; R. Kötitz

1999-01-01

266

High-Tc SQUID gradiometer system for immunoassays  

Microsoft Academic Search

A high-Tc dc SQUID (superconducting quantum interference device) gradiometer was developed for magnetic immunoassays where magnetic nanoparticles are used as markers to detect biological reactions. The gradiometer was fabricated on a 5 × 10 mm2 SrTiO3 bicrystal substrate and has a gradiometer resolution of 2.1 pT cm-1 Hz-1\\/2. A magnetic signal was detected from a sample of 1 µl of

F. Öisjöen; P. Magnelind; A. Kalabukhov; D. Winkler

2008-01-01

267

SQUID-Based Multiplexers for Transition Edge Sensor Readout  

Microsoft Academic Search

Theoretical background behind frequency- and time- domain multiplexing is given in the context of cryogenic readout of TES arrays. Some questions related to practical MUX implementation are covered, in particular the noise folding and dynamic range of the SQUID amplifier. Emphasis is on frequency domain multiplexing for X-ray sensors. (5-06) Frequency-Domain Multiplexing for Large-Scale Bolometer Arrays, (invited) Helmuth Spieler (LBNL)

Mikko Kiviranta; Heikki Seppä; Jan van der Kuur; Piet de Korte

2002-01-01

268

Macroscopic quantum interference phenomena in a 4-terminal SQUID  

NASA Astrophysics Data System (ADS)

A new kind of superconducting device, a 4-terminal SQUID, has been fabricated. It consists of a Josephson 4-terminal junction of which two terminals are short-circuited by a superconducting ring and the other two are connected to a current source, forming the transport circuit. Oscillations in the voltage at constant currents through the transport circuit are observed when a magnetic field applied to the ring changes.

Vleeming, B. J.; Zakarian, A. V.; Omelyanchouk, A. N.; de Bruyn Ouboter, R.

1996-02-01

269

Population dynamics in a metastable neon magneto-optical trap  

NASA Astrophysics Data System (ADS)

We observe the population dynamics within a metastable neon magneto-optical trap (MOT) through the measurement of the average squared Clebsch-Gordan coefficient C2 over a range of laser detunings. The magnitude of C2 is dependent on the internal quantum state of an atom interacting with the light field and is found to show a strong dependence on the applied laser detuning. Previously it has been reported [Townsend , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.52.1423 52, 1423 (1995)] that trapped atoms in a MOT are pumped towards the states that interact most strongly with the local field and therefore the measured value of C2 is larger than the average over all possible transitions. For the 3P2-to-3D3 cooling transition in metastable neon the average C2 value is equal to 0.46; however, we have measured 0.29±0.03

Glover, R. D.; Calvert, J. E.; Sang, R. T.

2013-02-01

270

Primitive neon isotopes in Terceira Island (Azores archipelago) [rapid communication  

NASA Astrophysics Data System (ADS)

We present the first neon data, as well as new helium data, on Terceira Island (Azores archipelago, Portugal). Clear 20Ne and 21Ne excesses compared to air are observed ( 20Ne/ 22Ne > 11.2) and moreover, the samples show a more primitive 21Ne/ 22Ne ratio than MORB, confirming that the Azores hotspot can be considered as sampling a "primitive", relatively undegassed, reservoir. Most 4He/ 3He isotopic ratios range between 80,000 and 63,500 (˜ 9 to 11.5 R/Ra), being similar to those previously reported by [1] [M. Moreira, R. Doucelance, B. Dupré, M. Kurz, C.J. Allègre, Helium and lead isotope geochemistry in the Azores archipelago, Earth Planet. Sci. Lett. 169 (1999) 189-205] . A more primitive 4He/ 3He ratio of ˜ 50,000 (R/Ra ˜ 15) was obtained in one sample, but we cannot completely exclude the possibility of a cosmogenic 3He contribution for this sample. Our study illustrates that the neon systematics can be more capable than helium to constrain the ultimate origin of hotspots in geodynamic settings dominated by plume-ridge interaction.

Madureira, Pedro; Moreira, Manuel; Mata, João; Allègre, Claude Jean

2005-05-01

271

Electronic Transitions of Protonated PAHs in 6 K Neon Matrices  

NASA Astrophysics Data System (ADS)

Protonated polycyclic aromatic hydrocarbons (H-PAH+s) are fundamental intermediates in organic chemistry and have been studied several decades ago in strong acidic solutions by NMR, IR and optical methods. Recently, they have been considered as possible carriers of certain diffuse interstellar bands (DIBs). According to TD-DFT calculations, such cations despite their closed-shell electronic structure could have strong transitions in the visible, where DIBs are detected. Diffuse interstellar absorption bands provide an unambiguous identification of interstellar molecules if their laboratory electronic spectra match astronomical observations. Therefore, the gas-phase spectroscopic measurements on H-PAH+s are necessary; they are limited currently to electronic spectra of protonated naphthalene and some larger protonated linear acenes. In the present contribution electronic absorption spectra of small H-PAH+s, anthracene, phenanthrene, pyrene and others, isolated in 6 K neon matrices are reported. The experimental setup is described. The cations of interest were produced in a hot-cathode discharge source, mass selected and codeposited with neon. The corresponding neutral species were produced in the same matrices by photobleaching the sample. The observed electronic transitions of the investigated species are compared to ab initio calculations, providing starting point for gas-phase measurements.

Garkusha, I.; Fulara, J.; Nagy, A.; Erattupuzha, S. M.; Maier, J. P.

2011-05-01

272

Statistical characterization of voltage-biased SQUIDs with weakly damped junctions  

NASA Astrophysics Data System (ADS)

Recently, it has been shown that voltage-biased readout of SQUIDs with weakly damped junctions (large Stewart-McCumber parameter ?c, 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 ? fabricated on 5 × 5 mm2 chips. The field-to-flux transfer coefficient ?B/?? of the magnetometers was 1.5 nT/?0, 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/??, are given. Nearly all the SQUIDs could be stably operated in the voltage bias mode and their ?V/?? reached a large mean value of 380 ?V/?0. 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 ??0 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.

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

273

Identified ion channels in the squid nervous system.  

PubMed

Our modern understanding of channels as discrete voltage-sensitive and ion-selective entities comes largely from a series of classical studies using the squid giant axon. This system has also been critical for understanding how transporters and synaptic transmission operate. This review outlines attempts to assign molecular identities to the extensively studied physiological properties of this system. As it turns out, this is no simple task. Molecular candidates for voltage-gated Na(+), K(+), and Ca(2+) channels, as well as ion transporters have been isolated from the squid nervous system. Both physiological and molecular approaches have been used to equate these cloned gene products with their native counterparts. In the case of the delayed rectifier K(+) conductance, the most thoroughly studied example, two major issues further complicate the equation. First, the ability of K(+) channel monomers to form heteromultimers with unique properties must be considered. Second, squid K(+) channel mRNAs are extensively edited, a process that can generate a wide variety of channel proteins from a common gene. The giant axon system is beginning to play an important role in understanding the biological relevance of this latter process. PMID:12904686

Rosenthal, J J C; Gilly, W F

274

Low-frequency nuclear quadrupole resonance with a dc SQUID  

SciTech Connect

Conventional pure nuclear quadrupole resonance (NQR) is a technique well suited for the study of very large quadrupolar interactions. Numerous nuclear magnetic resonance (NMR) techniques have been developed for the study of smaller quadrupolar interactions. However, there are many nuclei which have quadrupolar interactions of intermediate strength. Quadrupolar interactions in this region have traditionally been difficult or unfeasible to detect. This work describes the development and application of a SQUID NQR technique which is capable of measuring intermediate strength quadrupolar interactions, in the range of a few hundred kilohertz to several megahertz. In this technique, a dc SQUID (Superconducting QUantum Interference Device) is used to monitor the longitudinal sample magnetization, as opposed to the transverse magnetization, as a rf field is swept in frequency. This allows the detection of low-frequency nuclear quadrupole resonances over a very wide frequency range with high sensitivity. The theory of this NQR technique is discussed and a description of the dc SQUID system is given. In the following chapters, the spectrometer is discussed along with its application to the study of samples containing half-odd-integer spin quadrupolar nuclei, in particular boron-11 and aluminum-27. The feasibility of applying this NQR technique in the study of samples containing integer spin nuclei is discussed in the last chapter. 140 refs., 46 figs., 6 tabs.

Chang, J.W.

1991-07-01

275

NEON: Transforming Environmental Data into Free, Open Information  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) will collect data across the United States on the impacts of climate change, land use change and invasive species on natural resources and biodiversity. NEON is a project of the U.S. National Science Foundation (NSF), with many other U.S. agencies and NGOs cooperating. The Observatory’s construction plans call for 60 sites distributed across 20 ecoclimatic Domains. Data will be collected from strategically selected sites within each Domain and synthesized into information products that can be used to describe changes in the nation’s ecosystem through space and time. Sites are arrayed across different land-use types in order to understand large-scale environmental drivers affect biodiversity, ecohydrology, biogeochemistry, and disease ecology across the US continent. NEON is an instrument that listens to the pulse of the US continental ecosystem: infrastructure deployed at these sites will collect an average of over 500 primary measurements at each site, including annual high-resolution airborne LiDAR and hyperspectral data. These primary measurements will be transformed by a state-of-the-art cyberinfrastruture into over 100 higher-order data products. All measurements, data products, algorithms used to compute the data products, and protocols used to collect the primary measurements will be freely available to the public and assessable over the internet. The information products, including selected socio-economic datasets from cooperating Federal agencies, will be served in standard formats, grid-sizes, and geographical projections. This type of information is anticipated to have a wide range of uses, including ecological forecasting, education, public engagement, socio-economic analyses, decision support for climate-change adaptation and mitigation, resource management, and environmental risk management. Open data, interoperability, an open and integrated observation infrastructure, public engagement, and a deliberate approach to making sure that research data can be repurposed for operational purposes are the cornerstones of the NEON strategy: they facilitate the repurposing of credible, reliable data and information for multiple purposes. Often, the same data is useful in an undergraduate course on correlations as it is for public discourse on the effects of increased precipitation on stream water quality. This suggests a strategy for evolving an ecosystem of institutions whose primary responsibility is contributing to an open information commons that creates and curates credible sources of data and information products with clearly documented provenance, quality protocols, uncertainty estimates, and other qualitative descriptors. This information commons is deliberately designed to be tapped by another ecosystem of institutions whose individual missions revolve around some combination of discovery (e.g. research, forecasting, innovation), learning (e.g. public engagement, informal and formal learning, education research), and solutions (e.g. science and technology policy). This talk explores how the NEON information commons is envisioned to interact with this other community of institutions, and how the cornerstone principles enable that community to better focus their creative capabilities around their respective core missions.

Wee, B.

2010-12-01

276

Interpretation of helium and neon isotopic heterogeneity in Icelandic basalts  

NASA Astrophysics Data System (ADS)

New noble gas data from stepwise heating of nine samples from the Reykjanes Peninsula, Iceland, show total gas 3He/ 4He ratios ranging from relatively low values of 11±1 R/ Ra to higher values of 21±2 R/ Ra (where Ra=atmospheric 3He/ 4He ratio). These values are similar to previously measured ratios in Icelandic basalts, and higher than the average mid-ocean ridge basalt (MORB) 3He/ 4He ratio of ˜8.5 R/ Ra. Significantly, new neon isotopic data from five of these samples lie on, or above, the MORB trend in the neon three-isotope plot. These data provide the first strong evidence for a MORB-like neon isotopic component in Icelandic basalts. The remaining data lie on or near the air-solar mixing line, or within 1? of the atmospheric ratio. The combined new and previously published Icelandic mantle neon isotopic ratios range from MORB-like to solar-like compositions. The possible origins of this significant noble gas isotopic heterogeneity are evaluated in terms of two previously published models, the plume source model and the binary mixing model [Moreira et al., Earth Panet. Sci. Lett. 185 (2001) 15-23]. The plume source model is evaluated by comparison of the calculated 3He/ 22Ne elemental ratios from Iceland with the published estimates of the 3He/ 22Ne ratios in the solar nebula (1.9) and MORB (˜10). Most Icelandic 3He/ 22Ne (calculated) ratios are between ˜1 and 12 and suggest the Icelandic plume source is quite heterogeneous, but alternative explanations are possible. The heterogeneous Icelandic helium and neon isotopic ratios that give rise to the range in calculated 3He/ 22Ne ratios are also consistent with binary mixing between solar-like Icelandic plume- and MORB-derived noble gases. These end-members have specifically defined isotopic ratios but elemental ratios that may be variably modified. A large degree of recent relative elemental fractionation of He/Ne ratios in the Icelandic plume and MORB end-members would be needed to produce the observed range in isotopic ratios. The binary mixing model was further evaluated by comparison of Icelandic data with those from the Shona Ridge, a locality where binary mixing is believed to occur. In a plot of calculated 3He/ 22Ne and 21Ne/ 22Ne ratios, the Icelandic and Shona Ridge data form divergent linear trends that can be reconciled with binary mixing and that, interestingly, intersect at values of 1.6 and 0.036, respectively. These values are similar to the estimated solar nebula composition (1.9 and 0.0328). Such low calculated 3He/ 22Ne ratios have not been determined previously in terrestrial mantle-derived samples and may suggest that the plume source contains a component that is relatively unfractionated compared with the primordial solar nebula composition. Published steady-state upper mantle models require that the 3He/ 22Ne ratios in the plume (lower mantle) and MORB (upper mantle) sources are about equal to each other. The calculated 3He/ 22Ne ratio of near 1.6, inferred to represent the Icelandic and Shona Ridge mantle plume source composition, is dissimilar from the estimated MORB 3He/ 22Ne ratio of near 10. This appears to suggest the upper mantle is not at steady state with respect to the plume source mantle. The results of this study do not rule out the possible existence of Icelandic plume source noble gas elemental and isotopic heterogeneity. However, they do suggest that evidence for plume source heterogeneity may be obscured as a result of relatively shallow-level elemental fractionation and binary mixing processes.

Dixon, Eleanor T.

2003-01-01

277

Predicting helium and neon adsorption and separation on carbon nanotubes by Monte Carlo simulation.  

PubMed

The adsorption of helium and neon mixtures on single-walled carbon nanotubes (SWCNTs) was investigated at various temperatures (subcritical and supercritical) and pressures using canonical Monte Carlo (CMC) simulation. Adsorption isotherms were obtained at different temperatures (4, 40, 77 and 130 K) and pressures ranging from 1 to 16 MPa. Separation factors and isosteric enthalpies of adsorption were also calculated. Moreover, the adsorption isotherms were obtained at constant specific temperatures (4 and 40 K) and pressures (0.2 and 1.0 MPa) as a function of the amount adsorbed. All of the adsorption isotherms for an equimolar mixture of helium and neon have a Langmuir shape, indicating that no capillary condensation occurs. Both the helium and the neon adsorption isotherms exhibit similar behavior, and slightly more of the helium and neon mixture is adsorbed on the inner surfaces of the SWCNTs than on their outer surfaces. More neon is adsorbed than helium within the specified pressure range. The data obtained show that the isosteric enthalpies for the adsorption of neon are higher than those for helium under the same conditions, which means that adsorption of neon preferentially occurs by (15, 15) SWCNTs. Furthermore, the isosteric enthalpies of adsorption of both gases decrease with increasing temperature. PMID:20559855

Bolboli Nojini, Zabiollah; Abbas Rafati, Amir; Majid Hashemianzadeh, Seyed; Samiee, Sepideh

2010-06-18

278

SQUID detected NMR and NQR. Superconducting Quantum Interference Device.  

PubMed

The dc Superconducting QUantum Interference Device (SQUID) is a sensitive detector of magnetic flux, with a typical flux noise of the order 1 muphi0 Hz(-1/2) at liquid helium temperatures. Here phi0 = h/2e is the flux quantum. In our NMR or NQR spectrometer, a niobium wire coil wrapped around the sample is coupled to a thin film superconducting coil deposited on the SQUID to form a flux transformer. With this untuned input circuit the SQUID measures the flux, rather than the rate of change of flux, and thus retains its high sensitivity down to arbitrarily low frequencies. This feature is exploited in a cw spectrometer that monitors the change in the static magnetization of a sample induced by radio frequency irradiation. Examples of this technique are the detection of NQR in 27Al in sapphire and 11B in boron nitride, and a level crossing technique to enhance the signal of 14N in peptides. Research is now focused on a SQUID-based spectrometer for pulsed NQR and NMR, which has a bandwidth of 0-5 MHz. This spectrometer is used with spin-echo techniques to measure the NQR longitudinal and transverse relaxation times of 14N in NH4ClO4, 63+/-6 ms and 22+/-2 ms, respectively. With the aid of two-frequency pulses to excite the 359 kHz and 714 kHz resonances in ruby simultaneously, it is possible to obtain a two-dimensional NQR spectrum. As a third example, the pulsed spectrometer is used to study NMR spectrum of 129Xe after polariza-tion with optically pumped Rb. The NMR line can be detected at frequencies as low as 200 Hz. At fields below about 2 mT the longitudinal relaxation time saturates at about 2000 s. Two recent experiments in other laboratories have extended these pulsed NMR techniques to higher temperatures and smaller samples. In the first, images were obtained of mineral oil floating on water at room temperature. In the second, a SQUID configured as a thin film gradiometer was used to detect NMR in a 50 microm particle of 195Pt at 6 mT and 4.2 K. PMID:9650797

Augustine, M P; TonThat, D M; Clarke, J

1998-03-01

279

Measurement and modelling of neon radiation profiles in radiating boundary discharges in ASDEX Upgrade  

NASA Astrophysics Data System (ADS)

The radiation and transport characteristics of ASDEX Upgrade discharges with a neon-driven radiative mantle are modelled using a one-dimensional radial impurity transport code that has been coupled to a simple divertor model describing particle recycling and pumping. The code is well suited to describing the measured impurity line radiation, total, soft x-ray and bremsstrahlung radiation in regions of the plasma that are not dominated by two-dimensional effects. The recycling and pumping behaviour of neon as well as the bulk transport of neon for radiative boundary scenarios are discussed.

Dux, R.; Kallenbach, A.; Bessenrodt-Weberpals, M.; Behringer, K.; Bosch, H.-S.; Fuchs, J. C.; Gehre, O.; Mast, F.; Poschenrieder, W.; Murmann, H.; Salzmann, H.; Schweinzer, J.; Suttrop, W.; ASDEX Upgrade Team; NI Team

1996-07-01

280

Formation-flying interferometry  

NASA Astrophysics Data System (ADS)

There are many advantages to space-based interferometry, but monolithic, single-spacecraft platforms set limits on the collecting area and baseline length. These constraints can be overcome by distributing the optical elements of the interferometer over a system of multiple spacecraft flying in precise formation, opening up new realms of angular resolution and sensitivity. While the principles of interferometry are the same as for structurally-connected systems, formation-flying interferometers must integrate a wide range of technologies to provide an optically stable platform capable of finding, tracking and measuring fringes. This paper discusses some of the key differences between formation-flying and structurally-connected interferometers, including formation configurations, controlling beam shear, station-keeping, and the importance of delay and delay rate estimation in determining the instrument sensitivity. Proposed future formation-flying interferometer missions include the Terrestrial Planet Finder (TPF), Darwin, the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS), the Stellar Imager, the Micro-Arcsecond Xray Imaging Mission (MAXIM), and its precursor, MAXIM Pathfinder. In addition, Life Finder and Planet Imager have been identified as two formation-flying missions capable of detailed characterization of habitable exo-planets. The parameters for these missions are compared and described briefly.

Lay, Oliver P.; Blackwood, Gary H.

2003-02-01

281

Spin exchange optical pumping of neon and its applications  

NASA Astrophysics Data System (ADS)

Hyperpolarized noble gases are used in a variety of applications including medical diagnostic lung imaging, tests of fundamental symmetries, spin filters, atomic gyroscopes, and atomic magnetometers. Typically 3He is utilized because large 3He polarizations on the order of 80% can be achieved. This is accomplished by optically pumping an alkali vapour which polarizes a noble gas nucleus via spin exchange optical pumping. One hyperpolarized noble gas application of particular importance is the K-3He co-magnetometer. Here, the alkali atoms optically pump a diamagnetic noble gas. The magnetic holding field for the alkali and noble gas is reduced until both species are brought into hybrid magnetic resonance. The co-magnetometer exhibits many useful attributes which make it ideal for tests of fundamental physics, such as insensitivity to magnetic fields. The co-magnetometer would demonstrate increased sensitivity by replacing 3He with polarized 21Ne gas. Tests of CPT violation using co-magnetometers would be greatly improved if one utilizes polarized 21Ne gas. The sensitivity of the nuclear spin gyroscope is inversely proportional to the gyromagnetic ratio of the noble gas. Switching to neon would instigate an order of magnitude gain in sensitivity over 3He. In order to realize these applications the interaction parameters of 21Ne with alkali metals must be measured. The spin-exchange cross section sigmase, and magnetic field enhancement factor kappa0 are unknown, and have only been theoretically calculated. There are no quantitative predictions of the neon-neon quadrupolar relaxation rate Gammaquad. In this thesis I test the application of a K-3He co-magnetometer as a navigational gyroscope. I discuss the advantages of switching the buffer gas to 21Ne. I discuss the feasibility of utilizing polarized 21Ne for operation in a co-magnetometer, and construct a prototype 21Ne co-magnetometer. I investigate polarizing 21Ne with optical pumping via spin exchange collisions and measure the spin exchange rate coefficient of K and Rb with Ne to be 2.9 x 10-20cm 3/s and 0.81 x 10-19cm3/s. We measure the magnetic field enhancement factor kappa0 to be 30.8 +/- 2.7, and 35.7 +/- 3.7 for the K-Ne, and the Rb-Ne pair. We measure the quadrupolar relaxation coefficient to be 214 +/- 10 Amagat?s. Furthermore the spin destruction cross section of Rb, and K with 21 Ne is measured to be 1.9 x 10-23cm2 and 1.1 x 10-23cm2.

Ghosh, Rajat K.

282

Mechanism of the tunable structural color of neon tetra  

NASA Astrophysics Data System (ADS)

Many examples of the structural color can be found in butterfly wings, beetle's elytra and bird feathers. Since the color-producing microstructures of these examples mainly consist of stable materials, for example, dried cuticles in insects and keratin and melanin granules in bird feathers, it is impossible to actively change the microstructure. On the other hand, some fish have the tunability in their structural colors. For example, a small tropical fish, neon tetra, has a longitudinal stripe that looks blue-green in the day time, while it changes into deep violet at night. This fact clearly indicates the variability in the microstructure. It is known that the iridophore of the stripe part of neon tetra contains two stacks of thin light-reflecting platelets that are made of guanine crystal. Since the arrangement of the platelets is observed periodic, the stack is thought to cause the structural color through the multilayer thin-film interference. Consequently, the variability in the color is thought to originate from the variation in the distance between the platelets. Two explanations have been proposed so far for the distance variation. Lythoge and Shand considered that the distance is controlled by osmotic pressure that induces the inflow of the water into the iridophore[1]. On the other hand, Nagaishi et al. proposed a different model, called Venetian blind model, in which the inclination angle of the platelets is varied, resulting in the change in the distance[2]. Recently, we have performed detailed optical measurements on the iridophore of neon tetra. We have paid particular attention to the direction of the reflected light, since the Venetian blind model expects that the direction varies with the color change owing to the tilt of the platelets. We present the experimental results and quantitatively discuss the validity of the Venetian blind model. [4pt] [1] J. N. Lythgoe, and J. Shand, J Physiol. 325, 23-34 (1982). [0pt] [2] H. Nagaishi, N. Oshima, and R. Fujii, Comp. Biochem. Physiol. 95A, 337-341 (1990).

Yoshioka, Shinya

2010-03-01

283

A preliminary investigation of the use of subcutaneous tagging in Caribbean reef squid Sepioteuthis sepioidea (Cephalopoda: Loliginidae)  

Microsoft Academic Search

This paper describes a new method developed to directly measure size and temperature specific growth rates of individual wild squid. Our tag and recapture method is complimentary to previously employed statolith aging methods but provides finer scale detail. The Caribbean reef squid, Sepioteuthis sepioidea, is an ideal model organism for field work on squid life-history as they live in shallow

S. E. Replinger; J. B. Wood

2007-01-01

284

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

Federal Register 2010, 2011, 2012, 2013

...Alaska; Sculpins, Sharks, Squid, and Octopus in the Gulf of Alaska AGENCY: National...fishing for sculpins, sharks, squid, and octopus in the Gulf of Alaska (GOA). This action...TAC) of sculpins, sharks, squid, and octopus in the GOA. DATES: Effective 1200...

2011-01-19

285

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

Microsoft Academic Search

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

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

2009-01-01

286

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

Microsoft Academic Search

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

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

1995-01-01

287

The set-up of a high temperature superconductor radio-frequency SQUID microscope for magnetic nanoparticle detection  

Microsoft Academic Search

SQUID (superconducting quantum interference device) microscopes are versatile instruments for biosensing applications, in particular for magnetic nanoparticle detection in immunoassay experiments. We are developing a SQUID microscope based on an HTS rf SQUID magnetometer sensor with a substrate resonator. For the cryogenic set-up, a configuration was realized in which the cryostat is continuously refilled and kept at a constant liquid

M. Schmidt; H.-J. Krause; M. Banzet; D. Lomparski; J. Schubert; W. Zander; Y. Zhang; R. Akram; M. Fardmanesh

2006-01-01

288

Helium and Neon Abundances and Compositions in Cometary Matter  

SciTech Connect

Materials trapped and preserved in comets date from the earliest history of the solar system. Particles captured by the Stardust spacecraft from comet Wild 2 are indisputable cometary matter available for laboratory study. Here they report measurements of noble gases in Stardust material. neon isotope ratios are within the range observed in 'phase Q', a ubiquitous, primitive organic carrier of noble gases in meteorites. Helium displays {sup 3}He/{sup 4}He ratios twice those in phase Q and in Jupiter's atmosphere. Abundances per gram are surprisingly large, suggesting implantation by ion irradiation. The gases are carried in high temperature igneous grains similar to particles found in other Stardust studies. Collectively the evidence points to gas acquisition in a hot, high ion flux nebular environment close to the young Sun.

Marty, B; Palma, R L; Pepin, R O; Zimmmermann, L; Schlutter, D J; Burnard, P G; Westphal, A J; Snead, C J; Bajt, S; Becker, R H; Simones, J E

2007-10-15

289

Nitrogen and neon retention in plasma-facing materials  

NASA Astrophysics Data System (ADS)

Tungsten plate was exposed in the TEXTOR tokamak during nitrogen-assisted discharges. In order to determine material mixing on tungsten, the plate was examined ex situ with ion beam analysis techniques including time-of-flight heavy ion elastic recoil detection analysis and also with X-ray photoelectron spectroscopy. Nitrogen content in the range from 1.3 × 1015 to 3.4 × 1015 cm-2 is measured in the outermost surface layer (20 nm) of the W plate. Photoelectron spectroscopy detects nitrogen both in the elemental and compound form, i.e. tungsten nitride (WN/W2N). Nitrogen is measured even in hot areas free from deuterium. Also neon co-implantation into the plasma-facing components has been identified following Ne-cooled pulses.

Rubel, M.; Philipps, V.; Marot, L.; Petersson, P.; Pospieszczyk, A.; Schweer, B.

2011-08-01

290

Solid neon moderated electrostatic or magnetic positron beam  

SciTech Connect

A high intensity variable energy positron beam has been constructed at Brookhaven National Laboratory (BNL). Positrons from a 97mCi {sup 22}Na source are moderated by a thin layer of solid neon. A magnetic guiding system delivered up to 5{times}10{sup 6}e{sup +}/sec to an experiment. Currently tests are under way to facilitate the operation with the magnetic guiding system or -- for other experimental sites -- with an electrostatic beam transport. The electrostatic lenses are fabricated from {mu}-metal. No compensation of the earth magnetic field is required. Several experiments can utilize the beam on a time sharing basis. In the near future the source will be replaced by {sup 64}Cu which has a much higher activity. Beam intensities up to 10{sup 9}e{sup +}/sec are expected.

Weber, M.; Schwab, A. [Bielefeld Univ. (Germany). Fakultaet fuer Physik; Becker, D.; Lynn, K.G. [Brookhaven National Lab., Upton, NY (United States)

1991-12-31

291

What Is the Neon Abundance of the Sun?  

NASA Astrophysics Data System (ADS)

We have evolved a series of 13 complete solar models that utilize different assumed heavy-element compositions. Models that are based upon the heavy-element abundances recently determined by Asplund and coworkers are inconsistent with helioseismological measurements. However, models in which the neon abundance is increased by 0.4-0.5 dex to logN(Ne)=8.29+/-0.05 [on the scale in which logN(H)=12] are consistent with the helioseismological measurements even though the other heavy-element abundances are in agreement with the determinations of Asplund et al. These results sharpen and strengthen an earlier study by Antia & Basu. The predicted solar neutrino fluxes are affected by the uncertainties in the composition by less than their 1 ? theoretical uncertainties.

Bahcall, John N.; Basu, Sarbani; Serenelli, Aldo M.

2005-10-01

292

Solid neon moderated electrostatic or magnetic positron beam  

SciTech Connect

A high intensity variable energy positron beam has been constructed at Brookhaven National Laboratory (BNL). Positrons from a 97mCi {sup 22}Na source are moderated by a thin layer of solid neon. A magnetic guiding system delivered up to 5{times}10{sup 6}e{sup +}/sec to an experiment. Currently tests are under way to facilitate the operation with the magnetic guiding system or -- for other experimental sites -- with an electrostatic beam transport. The electrostatic lenses are fabricated from {mu}-metal. No compensation of the earth magnetic field is required. Several experiments can utilize the beam on a time sharing basis. In the near future the source will be replaced by {sup 64}Cu which has a much higher activity. Beam intensities up to 10{sup 9}e{sup +}/sec are expected.

Weber, M.; Schwab, A. (Bielefeld Univ. (Germany). Fakultaet fuer Physik); Becker, D.; Lynn, K.G. (Brookhaven National Lab., Upton, NY (United States))

1991-01-01

293

Helium and neon abundances and compositions in cometary matter.  

PubMed

Materials trapped and preserved in comets date from the earliest history of the solar system. Particles captured by the Stardust spacecraft from comet 81P/Wild 2 are indisputable cometary matter available for laboratory study. Here we report measurements of noble gases in Stardust material. Neon isotope ratios are within the range observed in "phase Q," a ubiquitous, primitive organic carrier of noble gases in meteorites. Helium displays 3He/4He ratios twice those in phase Q and in Jupiter's atmosphere. Abundances per gram are surprisingly large, suggesting implantation by ion irradiation. The gases are probably carried in high-temperature igneous grains similar to particles found in other Stardust studies. Collectively, the evidence points to gas acquisition in a hot, high ion-flux nebular environment close to the young Sun. PMID:18174437

Marty, Bernard; Palma, Russell L; Pepin, Robert O; Zimmermann, Laurent; Schlutter, Dennis J; Burnard, Peter G; Westphal, Andrew J; Snead, Christopher J; Bajt, Sasa; Becker, Richard H; Simones, Jacob E

2008-01-01

294

The infrared spectrum of HOOH+ trapped in solid neon  

NASA Astrophysics Data System (ADS)

When a Ne:H2O2 mixture is codeposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, three new, photosensitive absorptions appear which can be assigned to the three infrared-active vibrational fundamentals of trans-HOOH+. When the Ne:H2O2 deposition system is pretreated with the vapors of D2O, the product absorptions include new peaks which can be attributed to vibrational fundamentals of trans-HOOD+ and trans-DOOD+. Density functional calculations of the vibrational fundamentals of the three hydrogen peroxide cation isotopologues support the proposed assignments. Broad, photosensitive product absorptions also appear near the positions of vibrational transitions of O3-, and may be contributed by a weakly bound complex of that species with H2O.

Thompson, Warren E.; Lugez, Catherine L.; Jacox, Marilyn E.

2012-10-01

295

Determination of the Solubility of Neon in Water and Extracted Human Fat.  

National Technical Information Service (NTIS)

A gas chromatographic technic in conjunction with a modified Van Slyke apparatus is described for the determination of the Bunsen absorption coefficient (alpha) for neon in water, olive oil, and extracted human fat. Essentially, the method consists of a d...

K. G. Ikels

1964-01-01

296

Ionization Equilibrium of Selected Elements from Neon to Tungsten of Interest in Tokamak Plasma Research.  

National Technical Information Service (NTIS)

Ionization equilibrium calculations have been extended to 12 selected elements from neon to tungsten, in order to cover all elements found in Tokamak plasmas (either naturally present or purposely added). (Atomindex citation 10:446745)

C. Breton C. de Michelis M. Finkenthal M. Mattioli

1978-01-01

297

In Search of Giant Squid: An Expedition Into the Depths of the Last Frontier  

NSDL National Science Digital Library

Plumbing the depths of the world's oceans for a creature that has historically touched the depths of human fears, the In Search of Giant Squid site chronicles the Smithsonian expeditions to learn more about the elusive Giant Squid, which has never been observed in its natural habitat.

298

Characteristics of a Switchable Superconducting Flux Transformer with a Dc-Squid  

Microsoft Academic Search

We have investigated the flux transfer characteristics of a switchable flux transformer comprising a superconducting loop and a DC-SQUID. This system can be used to couple multiple flux qubits with a controllable coupling strength. Its characteristics were measured by using a flux input coil and a DC-SQUID for readout coupled to the transformer loop in a dilution refrigerator. The observed

Y. Shimazu; T. Niizeki

2008-01-01

299

Circulating current in a superconducting loop interrupted by a DC-SQUID with asymmetry  

Microsoft Academic Search

A superconducting loop interrupted by a DC-SQUID may be applied for coupling flux qubits with controllable coupling strength. In reality, complete switching off cannot be realized due to the asymmetry in the Josephson junctions in the DC-SQUID. We studied the effect of the asymmetry on the flux transfer characteristic. Numerical calculation showed that the leakage of the input flux in

Y. Shimazu; T. Niizeki; Z. Wada; Y. Saito

2007-01-01

300

Population structure between environmentally transmitted vibrios and bobtail squids using nested clade analysis  

Microsoft Academic Search

Squids from the genus Euprymna (Cephalopoda: Sepiolidae) and their symbiotic bacteria Vibrio fischeri form a mutualism in which vibrios inhabit a complex light organ within the squid host. A host-mediated daily expulsion event seeds surrounding seawater with symbiotically capable V. fischeri that environmentally colonize newly hatched axenic Euprymna juveniles. Competition experiments using native and non-native Vibrio have shown that this

B. W. JONES; J. E. LOPEZ; J. HUTTENBURG; M. K. NISHIGUCHI

2006-01-01

301

Nutritive value of squid and hydrolyzed protein supplement in shrimp feed  

Microsoft Academic Search

Though some protein sources like squid and protein hydrolysates are assumed as growth enhancers for shrimp, little is known about the biochemical basis of this phenomenon. Low, heat-dried squid (Dosidicus gigas) (SQ) and two commercial protein hydrolysates from fish (FH) and krill (Euphasia sp.) (KH) were assayed in feeding trials with Penaeus vannamei. Feeds were prepared with the tested proteins

Julio Humberto Córdova-Murueta; Fernando Luis Garc??a-Carreño

2002-01-01

302

Feasibility of detecting artificial magnetic anomalies in hydrofractured rock by superconducting gradiometer-SQUID systems  

Microsoft Academic Search

A study of the signal physics of magnetic anomaly detection by superconducting gradiometer-SQUID systems to determine the feasibility of possible applications to the geothermal energy program is described. The system would make full use of the incredible sensitivity of the superconducting quantum interference device (SQUID) which can be in the range of 10¹¹ Oe. In addition to magnetic anomalies in

Overton; W. C. Jr

1976-01-01

303

The properties of HTS Josephson junctions and DC SQUIDs fabricated on MgO bicrystals  

Microsoft Academic Search

We have fabricated HTS Josephson Junctions and DC SQUIDs using MgO bicrystals and YBCO thin films grown by PLD. The electrical and noise properties of the junctions have been measured. The SQUIDs have been designed and fabricated for use in our NDE programme. For this reason, their performance in unshielded environments is discussed here

E. J. Romans; T. G. Henrici; C. Carr; J. C. MacFarlane; C. M. Pegrum; G. B. Donaldson

1997-01-01

304

Planar SQUID gradiometers fabricated on 24° and 30° SrTiO 3 bicrystals  

Microsoft Academic Search

HTS dc SQUID gradiometers have been fabricated on 24° and 30° SrTiO3 bicrystal substrates with slots and flux dams in the SQUID washers. The spatial response of such devices has been measured experimentally and compared with modelled results. Single layer devices, in terms of gradient sensitivity, have characteristics that deviate only slightly from idealized first order gradiometers. The low frequency

C. Carr; A. Eulenburg; E. Romans; C. M. Pegrum; G. B. Donaldson

1999-01-01

305

Fully quantum-mechanical model of a SQUID ring coupled to an electromagnetic field  

Microsoft Academic Search

A quantum system comprising of a monochromatic electromagnetic field coupled to a superconducting quantum interference device (SQUID) ring with sinusoidal nonlinearity is studied. A magnetostatic flux Phix is also threading the SQUID ring, and is used to control the coupling between the two systems. It is shown that for special values of Phix the system is strongly coupled. The time

M. J. Everitt; P. B. Stiffell; T. D. Clark; A. Vourdas; J. F. Ralph; H. Prance; R. J. Prance

2001-01-01

306

A high-Tc flip-chip SQUID gradiometer for mobile underwater magnetic sensing  

Microsoft Academic Search

We report on the development of a magnetic gradient tensor sensor based on high- Tc SQUIDs for marine surveying applications. The proposed system uses six planar gradiometers incorporated into a hexagonal pyramid structure where the combined output will provide a measure of the gradient tensor. This report focuses on the development and characterization of long baseline high- Tc SQUID gradiometers

S. T. Keenan; J. A. Young; C. P. Foley; J. Du

2010-01-01

307

Improvement of sensitivity of multisample biological immunoassay system using HTS SQUID and magnetic nanoparticles  

Microsoft Academic Search

Recently, we have developed a prototype magnetic immunoassay system using a high temperature superconductor (HTS) superconducting quantum interference device (SQUID) to investigate the performance and usability of the magnetic immunoassay. In this study, we improved the immunoassay system to heighten the sensitivity of the immunoassay measurement. To reduce the SQUID-to-sample distance, we introduced a structure to compensate for thermal shrinkage

A. Tsukamoto; K. Saitoh; N. Sugita; H. Kuma; Y. Sugiura; S. Hamaoka; N. Hamasaki; K. Enpuku

2006-01-01

308

Electromagnetic nondestructive evaluation: moving HTS SQUIDs, inducing field nulling and dual frequency measurements  

Microsoft Academic Search

We have previously shown that simple, single layer HTS SQUIDs can be used effectively in electromagnetic nondestructive evaluation (NDE) using eddy current techniques in a magnetically unshielded environment. HTS SQUID systems for NDE applications are expected to be small and portable allowing non-stationary measurements to be carried out in the Earth's field above a stationary sample. Here we present application-oriented

C. Carr; D. Mc A. McKirdy; E. J. Romans; G. B. Donaldson; A. Cochran

1997-01-01

309

The Quality of Squid Held in Chilled Seawater Versus Conventional Shipboard Handling.  

National Technical Information Service (NTIS)

The two objectives of this work were to compare the fresh shelf life of squid held in chilled seawater (CSW) after being caught versus squid held in the traditional manner--iced down in boxes or iced down in pens aboard ship, and to compare the organolept...

V. G. Ampola

1980-01-01

310

SiGe Integrated Circuit/SQUID Hybrid Cryogenic Multiplexer for Superconducting Bolometer Array  

NASA Astrophysics Data System (ADS)

The development of large superconducting bolometer (Transition Edge Sensor: TES) arrays requires ultra low noise amplification and multiplexing electronics. The use of a first transducer stage such as a SQUID (Superconducting QUantum Interference Device) allows ultimate performance in terms of noise. However, the linearization of the SQUID characteristic requires low noise amplification. Furthermore, to realize a time domain multiplexer with SQUIDs, switched biasing is also needed. We have designed an Integrated Circuit (IC) in standard BiCMOS SiGe technology for the readout and the control of a SQUID multiplexer. It includes a low noise amplifier with multiplexed inputs, switched current sources for SQUIDs, and digital circuit for the addressing with only one room temperature clock signal. We have successfully tested this integrated circuit down to 2 K. To validate the operation of a SQUID multiplexer controlled by this SiGe cryogenic IC, we have developed a 2×2 SQUID hybrid demonstrator. It consists of four commercial SQUIDs connected to a SiGe IC.

Prêle, D.; Voisin, F.; Oger, R.; Chapron, C.; Bréelle, E.; Piat, M.

2009-12-01

311

Quantum dynamical structure factor of liquid neon via a quasiclassical symmetrized method.  

PubMed

We apply the phase integration method for quasiclassical quantum time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)] to compute the dynamic structure factor of liquid neon. So far the method had been tested only on model systems. By comparing our results for neon with experiments and previous calculations, we demonstrate that the scheme is accurate and efficient also for a realistic model of a condensed phase system showing quantum behavior. PMID:23406109

Monteferrante, Michele; Bonella, Sara; Ciccotti, Giovanni

2013-02-01

312

Method and apparatus for cooling high temperature superconductors with neon-nitrogen mixtures  

DOEpatents

Apparatus and methods for cooling high temperature superconducting materials (HTSC) to superconductive temperatures within the range of 27.degree. K. to 77.degree. K. using a mixed refrigerant consisting of liquefied neon and nitrogen containing up to about ten mole percent neon by contacting and surrounding the HTSC material with the mixed refrigerant so that free convection or forced flow convection heat transfer can be effected.

Laverman, Royce J. (South Holland, IL); Lai, Ban-Yen (Hinsdale, IL)

1993-01-01

313

Electron Ejection from an Atomically Clean Tungsten Surface by Helium and Neon Metastable Atoms  

Microsoft Academic Search

The absolute electron yield gammam of helium and neon metastable atoms incident on an atomically clean polycrystalline tungsten surface has been determined. The value of gammam for helium excited by 28-volt electrons is 0.306+\\/-0.025, where 1S0 and 3S1 yields are equal within an experimental error of 20%; the value of gammam for neon is 0.215+\\/-0.020. The contribution of each of

D. A. Maclennan

1966-01-01

314

Preservation of near-solar neon isotopic ratios in Icelandic basalts  

Microsoft Academic Search

Neon isotopic ratios measured in olivine and basaltic glass from Iceland are the most primitive observed so far in terrestrial mantle-derived samples. Ratios were measured in gas released from olivine and basaltic glass from a total of 10 samples from the Reykjanes Peninsula, Iceland, and one sample from central Iceland. The neon isotopic ratios include solar-like, mid-ocean ridge basalt (MORB)-like

Eleanor T. Dixon; Masahiko Honda; Ian McDougall; Ian H. Campbell; Ingvar Sigurdsson

2000-01-01

315

A determination of the neon isotopic composition of the deep mantle  

Microsoft Academic Search

The neon isotopic composition of the deep mantle, which allows to investigate formation processes of the Earth, is subject to debate. We have analyzed Ne trapped in fluid inclusions from plume-related Devonian rocks from the Kola Peninsula, Russia. The lower limit for pristine neon in the deep mantle is set at 20Ne\\/22Ne?13.0±0.2, close to the solar wind (SW) value. We

Reika Yokochi; Bernard Marty

2004-01-01

316

Shattering the myth of the resonantly photo-pumped neon-like titanium laser  

Microsoft Academic Search

Several years ago neon-like titanium (Z = 22) was made to lase at 326 â« on the 3p â 3s (J = 0 â 1) transition. At the time it was suggested that the lasing may be due to resonantly photo-pumping the neon-like titanium 2p â 4d lines using 3s â 2p and 3d â 2p lines in carbon-like and

J. Nilsen; B. J. MacGowan; L. B. Da Silva; J. C. Moreno; J. A. Koch

1993-01-01

317

Revisitation of the luminance conditions for the occurrence of the achromatic neon color spreading illusion  

Microsoft Academic Search

This paper develops the idea (Bressan, 1993) that neon spreading derives from the perceptual scissioning of ordinary assimilation\\u000a color, a process identical to that occurring with nonillusory colors in phenomenal transparency. It is commonly held that\\u000a the critical elements in achromatic neon spreading patterns must be of luminance intermediate between that of the embedding\\u000a lines and of the background. The

Paola Bressan

1993-01-01

318

Role for cheR of Vibrio fischeri in the Vibrio-Squid Symbiosis  

PubMed Central

Upon hatching, the Hawaiian squid Euprymna scolopes is rapidly colonized by its symbiotic partner, the bioluminescent marine bacterium Vibrio fischeri. V. fischeri cells present in the seawater enter the light organ of juvenile squid in a process that requires bacterial motility. In this study, we investigated the role chemotaxis may play in establishing this symbiotic colonization. Previously we reported that V. fischeri migrates toward numerous attractants, including N-acetylneuraminic acid (NANA), a component of squid mucus. However, whether or not migration toward an attractant such as squid-derived NANA helps the bacterium to localize toward the light organ is unknown. When tested for the ability to colonize juvenile squid, a V. fischeri chemotaxis mutant defective for the methyltransferase CheR was outcompeted by the wild-type strain in co-inoculation experiments, even when the mutant was present in 4-fold excess. Our results suggest that the ability to perform chemotaxis is an advantage during colonization, but not essential.

DeLoney-Marino, Cindy R.; Visick, Karen L.

2011-01-01

319

Robotic 3D SQUID imaging system for practical nondestructive evaluation applications  

NASA Astrophysics Data System (ADS)

A robotic three-dimensional (3D) scanning superconducting quantum interference device (SQUID) imaging system was developed for practical nondestructive evaluation (NDE) applications. The major feature of this SQUID NDE system is that the SQUID sensor itself scans in 3D by traveling over the surface of an object during testing without the need for magnetic shielding. This imaging system consists of (i) DC-SQUID gradiometer for effective movement of the sensor, (ii) SQUID sensor manipulator utilizing an articulated-type robot used in industry, (iii) laser charge-coupled-device (CCD) displacement sensor to measure the 3D coordinates of points on the surface of the object, and (iv) computer-aided numerical interpolation scheme for 3D surface reconstruction of the object. The applicability of this system for NDE was demonstrated by successfully detecting artificial damage of cylindrical-shaped steel tubes.

Isawa, K.; Nakayama, S.; Ikeda, M.; Takagi, S.; Tosaka, S.; Kasai, N.

2005-11-01

320

Axoplasmic RNA species synthesized in the isolated squid giant axon.  

PubMed

Isolated squid stellate nerves and giant fiber lobes were incubated for 8 hr in Millipore filtered sea water containing [3H]uridine. The electrophoretic patterns of radioactive RNA purified from the axoplasm of the giant axon and from the giant fiber lobe (cell bodies of the giant axon) demonstrated the presence of RNA species with mobilities corresponding to tRNA and rRNA. The presence of labeled rRNAs was confirmed by the behavior of the large rRNA component (31S) which, in the squid, readily dissociates into its two constituent moyeties (17S and 20S). Comparable results were obtained with the axonal sheath and the stellate nerve. In all the electrophoretic patterns, additional species of radioactive RNA migrated between the 4S and the 20S markers, i.e. with mobilities corresponding to presumptive mRNAs. Chromatographic analysis of the purified RNAs on oligo(dT)cellulose indicated the presence of labeled poly(A)+ RNA in all tissue samples. Radioactive poly(A)+ RNA represented approximately 1% of the total labeled RNA in the axoplasm, axonal sheath and stellate nerve, but more than 2% in the giant fiber lobe. The labeled poly(A)+ RNAs of the giant fibre lobe showed a prevalence of larger species in comparison to the axonal sheath and stellate nerve. In conclusion, the axoplasmic RNAs synthesized by the isolated squid giant axon appear to include all the major classes of axoplasmic RNAs, that is rRNA, tRNA and mRNA. PMID:2457819

Rapallino, M V; Cupello, A; Giuditta, A

1988-07-01

321

Multiplexing of Hot-Electron Nanobolometers Using Microwave SQUIDs  

NASA Astrophysics Data System (ADS)

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 (~?s 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 ?0/2 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.

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

2009-12-01

322

Flies as forensic indicators.  

PubMed

Synanthropic flies, particularly calliphorids, are initiators of carrion decomposition and, as such, are the primary and most accurate forensic indicators of time of death. The relevant biology and forensic applications of the egg, larva, pupa, and young adult are discussed for various species, with emphasis on thermal history and age markers. PMID:1941921

Greenberg, B

1991-09-01

323

Go Fly a Kite  

ERIC Educational Resources Information Center

This article describes an "art kite" activity. The idea is to construct and decorate a non-flying kite that they could display for an art exhibit. Through the activity, students learn to give and take suggestions from one another, improve the quality of their work and set a wonderful atmosphere of collaboration. (Contains 1 online resource.)

Klopack, Ken

2009-01-01

324

Proficiency Flying Programs.  

National Technical Information Service (NTIS)

The Directive implements Section 715, P.L. 92-204 and prescribes Department of Defense policy for the effective and economical conduct of proficiency flying programs. It incorporates the provisions of DoD Directive 1340.4, March 19, 1971, and ASD(M&RA) mu...

J. Shanahan

1972-01-01

325

Flying High with Spring.  

ERIC Educational Resources Information Center

Presents an art activity for first grade that uses multicolor scratch paper. Explains that students make scratch-drawings of bird nests, then, as a class, discuss types of birds and bird positions (such as sitting or flying), and finally each creates a bird to add to the nest. (CMK)

Harrington, Carolyn Lang

2000-01-01

326

Project Report Flying Freedom  

Microsoft Academic Search

The Flying Freedom project is a part of the Communication Systems Design course at the Royal Institute of Technology, Stockholm, Sweden. The project started in February and ended in the end on June 2001. The project team has delivered a system architecture and protocol design to improve the functionality of the commercial Freedom System, from the Canadian company Zero-Knowledge Systems.

Per Heselius; Martin Hedenfalk

2001-01-01

327

A scanning SQUID microscope for imaging high-frequency magnetic fields  

NASA Astrophysics Data System (ADS)

This thesis examines the design and operation of a large-bandwidth scanning SQUID microscope for spatially imaging high frequency magnetic fields. Towards this end, I present results on a cryo-cooled 4.2 K scanning SQUID microscope with a bandwidth of dc to 2 GHz and a sensitivity of about 52.4 nT per sample. By using a thin-film hysteretic Nb dc-SQUID and a pulsed sampling technique, rather than a non-hysteretic SQUID and a flux-locked loop, the bandwidth limitation of existing scanning SQUID microscopes is overcome. The microscope allows for non-contact images of time-varying magnetic field to be taken of room-temperature samples with time steps down to 50 ps and spatial resolution ultimately limited by the size of the SQUID to about 10 mum. The new readout scheme involves repeatedly pulsing the bias current to the dc SQUID while the voltage across the SQUID is monitored. Using a fixed pulse amplitude and applying a fixed dc magnetic flux allows the SQUID to measure the applied magnetic flux with a sampling time set by the pulse length of about 400 ps. To demonstrate the capabilities of the microscope, I imaged magnetic fields from 0 Hz (static fields) up to 4 GHz. Samples included a magnetic loop, microstrip transmission lines, and microstrip lines with a break in order to identify and isolate electrical opens in circuits. Finally, I discuss the operation and modeling of the SQUID and how to further increase the bandwidth of the microscope to allow bandwidth of upwards of 10 GHz.

Vlahacos, Constantine P.

328

Quantum dynamics in a camelback potential of a dc SQUID.  

PubMed

We investigate a quadratic-quartic anharmonic oscillator formed by a potential well between two potential barriers. We realize this novel potential with a dc SQUID at near-zero current bias and flux bias near half a flux quantum. Escape out of the central well can occur via tunneling through either of the two barriers. We find good agreement with a generalized double-path macroscopic quantum tunneling theory. We also demonstrate an "optimal line" in current and flux bias along which the oscillator, which can be operated as a phase qubit, is insensitive to decoherence due to low-frequency current fluctuations. PMID:19392556

Hoskinson, E; Lecocq, F; Didier, N; Fay, A; Hekking, F W J; Guichard, W; Buisson, O; Dolata, R; Mackrodt, B; Zorin, A B

2009-03-06

329

Sensitivity and spatial resolution of square loop SQUID magnetometers  

NASA Astrophysics Data System (ADS)

We calculate the flux threading the pick-up coil of a square SQUID magnetometer in the presence of a current dipole source. The result reproduces that of a circle coil magnetometer calculated by Wikswo [J.P. Wikswo, AIP Conf. Proc. 44 (1978) 145] with only small differences. However it has a simpler form so that it is possible to derive from it closed form expressions for the current dipole sensitivity and the spatial resolution. The results are useful to assess the overall performance of the device and allow the comparison of magnetometers with different detection coil size.

Rombetto, S.; Vettoliere, A.; Granata, C.; Russo, M.; Nappi, C.

2008-12-01

330

Magnetic evaluation of a solar panel using HTS-SQUID  

NASA Astrophysics Data System (ADS)

The magnetic evaluation system of a solar panel using HTS-SQUID has been proposed and developed. A normal pick-up coil was applied to detect the tangential magnetic field to the panel surface. Since the detected field could be related to the currents of the solar panels, the electric properties of the solar panels could be evaluated. In this work, the evaluation of the electric properties of the commercial solar panels as well as the electric circuits made by the discrete devices on the circuit board was visualized.

Kiwa, Toshihiko; Fukudome, Yohei; Miyazaki, Shingo; Saari, Mohd Mawardi; Sakai, Kenji; Tsukada, Keiji

2013-11-01

331

Issues relating to airborne applications of HTS SQUIDs  

NASA Astrophysics Data System (ADS)

Airborne application of HTS SQUIDs is the most difficult environment for their successful deployment. In order to operate with the sensitivity required for a particular application, there are many issues to be addressed such as the need for very wide dynamic range electronics, motion noise elimination, immunity to large changing magnetic fields and cultural noise sources. This paper reviews what is necessary to achieve an airborne system giving examples in geophysical mineral exploration. It will consider issues relating to device design and fabrication, electronics, dewar design, suspension system requirements and noise elimination methods.

Foley, C. P.; Leslie, K. E.; Binks, R. A.; Lam, S. H. K.; Du, J.; Tilbrook, D. L.; Mitchell, E. E.; Macfarlane, J. C.; Lee, J. B.; Turner, R.; Downey, M.; Maddever, A.

2002-12-01

332

Quantum Behavior of the dc SQUID phase qubit.  

NASA Astrophysics Data System (ADS)

We analyze the quantum behavior of a SQUID phase qubit in which one junction acts as a qubit while the other filters out any external low frequency bias current noise. We solve Schr"odinger's equation for the two dimensional Hamiltonian of the system at zero temperature assuming no dissipation. We obtain the states and from these the energy levels, tunneling rates, and expectation values of the currents in the junctions. We use these results to show how this design isolates the system from noise without affecting the essential nature of the qubit. This work is funded by the NSA, NSF Grant EIA 0323261, and the Center for Superconductivity Research.

Mitra, Kaushik; Strauch, F. W.; Paik, Hanhee; Dutta, S. K.; Lewis, R. M.; Palomaki, T. A.; Przybysz, A. J.; Cooper, B. K.; Dragt, A. J.; Anderson, J. R.; Lobb, C. J.; Wellstood, F. C.

2007-03-01

333

Evidence of Microstates in dc SQUID Phase Qubits  

NASA Astrophysics Data System (ADS)

We report experimental results consistent with external quantum systems coupling to a Josephson junction phase qubit. When the energy level spacing for the qubit is made equal to that of the fixed external system the coupling lifts the degeneracy. By applying microwaves to excite transitions in the qubit, we are able to map out the splittings in the spectrum due to the coupling. This effect has been seen in both an Al/AlOx/Al and a Nb/AlOx/Nb dc SQUID phase qubit. This work is supported by the NSA, NSF Grant EIA 0323261, and the Center for Superconductivity Research.

Palomaki, Tauno; Dutta, Sudeep; Lewis, Rupert; Przybysz, Anthony; Paik, Hanhee; Mitra, Kaushik; Cooper, Ben; Kwon, Hyeokshin; Dragt, Alex; Anderson, J. R.; Lobb, Chris; Wellstood, Fred

2007-03-01

334

Fear of flying: an overview.  

PubMed

Flying gives the aviator a sense of power and control. Aviators challenge their own skills and test the physical limitations of the plane. They must maintain the balance between fear and joy, sacrifice and love, and risks and rewards of flying in order to continue to fly without reservation. Flying is dangerous. The danger is both real and symbolic, generating fears and anxiety. Interpretation of fear of flying spans from the psychoanalytic-endogenous on one side to the behaviouristic-exogenous on the other side. Unless strictly understood, both models should be taken to consider the interaction between the endogenous and exogenous factors. The therapy of the fear of flying is based on the correlation between the symptoms and underlying dynamics. The prognosis depends on the ability to work through those psychodynamic conflicts. Aviators may continue to fly if the symptoms are minor and the motivation to resolve conflicts is high. PMID:11276969

Jureti?, Z

2000-12-01

335

Evidence for myosin motors on organelles in squid axoplasm.  

PubMed Central

Squid axoplasm has proved a rich source for the identification of motors involved in organelle transport. Recently, squid axoplasmic organelles have been shown to move on invisible tracks that are sensitive to cytochalasin, suggesting that these tracks are actin filaments. Here, an assay is described that permits observation of organelles moving on unipolar actin bundles. This assay is used to demonstrate that axoplasmic organelles move on actin filaments in the barbed-end direction, suggesting the presence of a myosin motor on axoplasmic organelles. Indeed, axoplasm contains actin-dependent ATPase activity, and a pan-myosin antibody recognized at least four bands in Western blots of axoplasm. An approximately 235-kDa band copurified in sucrose gradients with KI-extracted axoplasmic organelles, and the myosin antibody stained the organelle surfaces by immunogold electron microscopy. The myosin is present on the surface of at least some axoplasmic organelles and thus may be involved in their transport through the axoplasm, their movement through the cortical actin in the synapse, or some other aspect of axonal function. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4

Bearer, E L; DeGiorgis, J A; Bodner, R A; Kao, A W; Reese, T S

1993-01-01

336

Neural control of tuneable skin iridescence in squid  

PubMed Central

Fast dynamic control of skin coloration is rare in the animal kingdom, whether it be pigmentary or structural. Iridescent structural coloration results when nanoscale structures disrupt incident light and selectively reflect specific colours. Unlike animals with fixed iridescent coloration (e.g. butterflies), squid iridophores (i.e. aggregations of iridescent cells in the skin) produce dynamically tuneable structural coloration, as exogenous application of acetylcholine (ACh) changes the colour and brightness output. Previous efforts to stimulate iridophores neurally or to identify the source of endogenous ACh were unsuccessful, leaving researchers to question the activation mechanism. We developed a novel neurophysiological preparation in the squid Doryteuthis pealeii and demonstrated that electrical stimulation of neurons in the skin shifts the spectral peak of the reflected light to shorter wavelengths (greater than 145 nm) and increases the peak reflectance (greater than 245%) of innervated iridophores. We show ACh is released within the iridophore layer and that extensive nerve branching is seen within the iridophore. The dynamic colour shift is significantly faster (17 s) than the peak reflectance increase (32 s), revealing two distinct mechanisms. Responses from a structurally altered preparation indicate that the reflectin protein condensation mechanism explains peak reflectance change, while an undiscovered mechanism causes the fast colour shift.

Wardill, T. J.; Gonzalez-Bellido, P. T.; Crook, R. J.; Hanlon, R. T.

2012-01-01

337

Temperature dependence of tetrodotoxin effect in squid giant axons.  

PubMed Central

1. The effects of temperature changes from 30 to 5 degrees C on some properties of giant axons of the squid Doryteuthis plei were studied under voltage-clamp conditions. 2. The maximum inward sodium current of giant axons held at their normal resting potential decreases from 8 to 2 mA/cm2 when the temperature is lowered from 21 to 5 degrees C. 3. The effect of tetrodotoxin on those axons and its steady-state kinetics are markedly temperature dependent. It appears that there are two types of receptors in squid axon membranes, which differ in their temperature dependence. 4. One group of receptors (type 1) increases its affinity for the toxin when the temperature is increased (maximum affinity at 30 degrees C, K1 = 0.03 +/- 0.01 nM). The other group of receptors (type 2) shows an increase in its affinity when the temperature is lowered (maximum affinity at 5 degrees C, K2 = 0.07 +/- 0.02 nM). At 10 degrees C the two populations have the same affinity (K1 = K2 = 0.67 +/- 0.06 nM).

Sevcik, C

1982-01-01

338

High-Tc SQUID Magnetometers for Industrial Applications  

NASA Astrophysics Data System (ADS)

We have developed high-Tc SQUID magnetometers for use in a variety of industrial applications. Relatively inexpensive direct-coupled magnetometers have been developed for low-frequency applications including fetal-magnetocardiography. A manufacturable process has been developed to reproducibly fabricate high-resistance (up to 6 ?) SNS step-edge junctions with YBa_2Cu_3O_7-x as the superconductor and Ag-Au alloy as the normal metal. Magnetic field sensitivities at 77K of 22 ft/Hz^1/2 at 1 KHz and 32 ft/Hz^1/2 at 1 Hz have been achieved in a well-shielded laboratory environment. Current effort is focused on operation in an unshielded environment using flux dams(Milliken et al. Appl. Phys. Lett. 71 1857 (1997)) in conjunction with narrow superconducting pickup coils placed in parallel. An integrated magnetometer process has also been optimized for use in high-frequency applications. The integrated megnetometer utilizes two layers of YBa_2Cu_3O_7-x and one layer of deposited SrTiO_3, all on the same 24 mm x 5 mm substrate. The applications under development include the detection of the explosive material in non-metallic land mines using nuclear quadrupole resonance as well as the non-destructive evaluation of non-metallic composites using nuclear magnetic resonance. For operation in the MHz regime, these applications demand a high quality insulator layer and a robust SQUID that can withstand high current transients.

Diiorio, Mark; Yang, Kai-Yueh; Yoshizumi, Shozo; Haupt, Steven; Haran, Don; Koch, Roger; Lathrop, Dan; Trammel, Hoke

1998-03-01

339

NDE of coated-conductor using HTS SQUID array  

NASA Astrophysics Data System (ADS)

We developed a non-destructive evaluation (NDE) system using an HTS SQUID array in order to examine rare-earth (RE)-123 HTS coated conductors striated into multi-filamentary lines. The 5-channel HTS SQUID gradiometer array was composed of ramp-edge junctions with LaErBaCuO and SmBaCuO electrode layers, and fabricated by using an HTS multi layer fabrication technique. The planar gradiometers with 1 × 1 mm2 pickup loops and a baseline of 1 mm detected the vertical element of magnetic field gradient induced around defects by an eddy current. The gradiometer array cooled by thermal conduction from a liquid nitrogen bath was placed above the coated conductor on the main stage with a lift-off of about 1.5 mm. A coated conductor was fed from a reel to reel, and cooled blow its Tc by stages connected to Gifford-Mcmahon (GM) coolers. By employing a 3 kHz induction current generating the maximum field of 0.14 mT, we could identify a distribution of defects in a long-length non-striated conductor. Furthermore, we could detect and distinguish three kinds of defects, existence of a spotty normal-state region, electrical short between striated filaments, and delamination of the superconducting layer from the Hastelloy tape for each filamentary superconducting line at a high speed up to 30 m/h.

Hato, T.; Adachi, S.; Sutoh, Y.; Hata, K.; Oshikubo, Y.; Machi, T.; Tanabe, K.

2009-10-01

340

Model of Auctioneer Estimation of Swordtip Squid (Loligo edulis) Quality  

NASA Astrophysics Data System (ADS)

The knowledge of experienced auctioneers regarding the circulation of marine products is an essential skill and is necessary for evaluating product quality and managing aspects such as freshness. In the present study, the ability of an auctioneer to quickly evaluate the freshness of swordtip squid (Loligo edulis) at fish markets was analyzed. Evaluation characteristics used by an auctioneer were analyzed and developed using a fuzzy logic model. Forty boxes containing 247 swordtip squid with mantles measuring 220 mm that had been evaluated and assigned to one of five quality categories by an auctioneer were used for the analysis and the modeling. The relationships between the evaluations of appearance, body color, and muscle freshness were statistically analyzed. It was found that a total of four indexes of the epidermis color strongly reflected evaluations of appearance: dispersion ratio of the head, chroma on the head-end mantle and the difference in the chroma and brightness of the mantle. The fuzzy logic model used these indexes for the antecedent-part of the linguistic rules. The results of both simulation and evaluations demonstrate that the model is robust, with the predicted results corresponding with more than 96% of the quality assignments of the auctioneers.

Nakamura, Makoto; Matsumoto, Keisuke; Morimoto, Eiji; Ezoe, Satoru; Maeda, Toshimichi; Hirano, Takayuki

341

[Comparative study of substrate and inhibitory specificity of monoamine oxidase in the optic ganglia of squids].  

PubMed

Comparative study of substrate specificity of monoamine oxidase (MAO) of optic ganglia of the Pacific squid Todarodes pacificus and the Commander squid Berryteuthis magister has been carried out. The enzyme of the Pacific squid, unlike that of the Commander squid, has been established to be able to deaminate not only tyramine, tryptamine, serotonin, benzylamine, and beta-phenylethylamine, but also histamine--substrate of diamine oxidase (DAO). In relation to all studied substrates, the MAO activity of optic ganglia of T. pacificus is several times higher as compared with B. magister. In the case of deamination of serotonin this difference was the greatest and amounted to 5 times. Semicarbazide, the classic DAO inhibitor, at a concentration of 10 mM did not inhibit catalytic activity of both studied enzymes. The substrate-inhibitory analysis with use of deprenyl and chlorogiline, specific inhibitors of different MAO forms, indicates homogeneity of the enzyme of the Pacific squid and heterogeneity of the Commander squid enzyme whose composition seems probably to contain at least two MAO forms. There are obtained quantitative differences in substrate specificity and reaction capability with respect to the inhibitors chlorgiline and deprenyl for MAO of optic ganglia of the studied squid species. These differences probably can be explained by significant differences in the evolutionary level of these biological species. PMID:20583578

Iagodina, O V

342

Phonotaxis in flying crickets  

Microsoft Academic Search

1.The effects of two-tone stimuli on the high frequency bat-avoidance steering behavior of flying crickets (Teleogryllus oceanicus) were studied during tethered flight. Similarly, the effects of two-tone stimuli on the ultrasound sensitive auditory interneuron, Int-1, which elicits this behavior, were studied using intracellular staining and recording techniques.2.When a low frequency tone (3–8 kHz) was presented simultaneously with an aversive high

Thomas G. Nolen; Ronald R. Hoy

1986-01-01

343

Detection of small magnetic fields using thick BSCCO film RF squid operating at 77 K  

NASA Astrophysics Data System (ADS)

A high Tc RF SQUID fabricated from thick BSCCO film using naturally present grain boundary weak links has been used for measuring small magnetic fields originating from an analogue quartz wrist watch and magnetic rock samples. For these measurements, the samples were kept at ambient temperature at a distance of ?4 cm from the SQUID, which was operated in the 'locked mode' at 77 K. The flux noise density of the SQUID in the white noise region was 5 × 10 -4 ? 0 Hz - 1/2 at 77 K.

Khare, N.; Gupta, A. K.; Chaudhry, S.

344

Development and Implementation of a 1 GHz SQUID amplifier for the Axion Dark Matter Experiment  

NASA Astrophysics Data System (ADS)

The Axion Dark Matter eXperiment (ADMX) was designed to detect ultra-weakly interacting relic axion particles by searching for their conversion to microwave photons in a resonant cavity positioned in a strong magnetic field. Given the extremely low expected axion-photon conversion power we have designed, built and operated a microwave receiver based on a Superconducting QUantum Interference Device (SQUID). We describe the implementation of a SQUID amplifier in the ADMX microwave receiver chain and discuss progress made at the Washington Micro-Fabrication Facility toward the production of SQUID amplifiers from a Nb-AlxOy-Nb trilayer.

Wagner, Andrew

2012-02-01

345

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

SciTech Connect

Axions in the {mu}eV 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. The first result from such an axion search using a superconducting first-stage amplifier (SQUID) is reported. The SQUID amplifier, replacing a conventional GaAs field-effect transistor amplifier, successfully reached axion-photon coupling sensitivity in the band set by present axion models and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.

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

2009-10-21

346

Protein synthesis in a solitary benthic cephalopod, the Southern dumpling squid (Euprymna tasmanica).  

PubMed

Rates of protein synthesis were measured in the whole body and tissues of southern dumpling squid Euprymna tasmanica to validate the use of a flooding-dose of (3)H phenylalanine for the measurement of protein synthesis with different size squid and to make a preliminary investigation into the effects of feeding regime. In smaller (2.8+/-0.5 g, mean+/-SE) and larger (14.8+/-2.2 g) squid whole body fractional rates of protein synthesis were 9.45+/-1.21 and 1.49+/-0.29% d(-1), respectively. Differences in total whole body protein content meant there was no difference in absolute rates of whole body protein synthesis between the larger and smaller squid. In larger squid, fractional rates of protein synthesis were significantly higher in the digestive gland (9.24+/-1.63% d(-1)) than in the arm tissue (1.43+/-0.31% d(-1)), which were significantly higher than in the anterior (0.56+/-0.13% d(-1)) and posterior (0.36+/-0.04% d(-1)) mantle. In smaller squid there were no differences in protein synthesis between tissues and high individual variation, due to differences in feeding, was a likely cause. Consequently, the effect of feeding regime on protein synthesis was compared between two groups of individually held squid: daily-feeding and minimal-feeding squid. The daily-feeding squid had significantly higher feed intake, gained mass and had a significantly higher growth rate than the minimal-feeding squid which lost mass. Whole body protein synthesis was significantly higher in the daily-feeding squid as was the protein content of the digestive gland, anterior and posterior mantle. There were few other differences in indices of protein metabolism. Individual squid showed differences in growth and protein metabolism, and there were significant relationships between growth rate and both rates of protein synthesis and protein degradation. Thus, higher individual growth was a consequence of increased protein synthesis, decreased protein degradation and, therefore, increased efficiency of retaining synthesised protein. PMID:19223018

Carter, Chris G; Lynch, Kerri A; Moltschaniwskyj, Natalie A

2009-02-15

347

Retinal degeneration in the fly.  

PubMed

Many genes are functionally equivalent between flies and humans. In addition, the same, or similar, mutations cause disease in both species. In fact, nearly three-fourths of all human disease genes have related sequences in Drosophila. The fly has a relatively small genome, made up of about 13,600 genes in four pairs of chromosomes. However, despite the dramatic differences in size and apparent complexity between humans and flies--we have less than twice as many genes as a fly--our genome is estimated to be made up of only 20,000-25,000 genes contained in 23 pairs of chromosomes. Therefore, despite the fly's perceived simplicity, or our perceived complexity, our genetic makeup may not be all that different. Its versatility for genetic manipulation and convenience for unraveling fundamental biological processes continue to guarantee the fly a place in the spotlight for unraveling the basis of and therapeutic treatments for human eye diseases. PMID:22183359

Colley, Nansi Jo

2012-01-01

348

Neutrino oscillation signatures of oxygen-neon-magnesium supernovae  

SciTech Connect

We discuss the flavor conversion of neutrinos from core-collapse supernovae that have oxygen-neon-magnesium (ONeMg) cores. Using the numerically calculated evolution of the star up to 650 ms post bounce, we find that, for the normal mass hierarchy, the electron neutrino flux in a detector shows signatures of two typical features of an ONeMg-core supernova: a sharp step in the density profile at the base of the He shell and a faster shock wave propagation compared to iron core supernovae. Before the shock hits the density step (t < or approx. 150 ms), the survival probability of electron neutrinos above {approx}20 MeV of energy is about {approx}0.68, in contrast to values of {approx}0.32 or less for an iron core supernova. The passage of the shock through the step and its subsequent propagation cause a decrease of the survival probability and a decrease of the amplitude of oscillations in the Earth, reflecting the transition to a more adiabatic propagation inside the star. These changes affect the lower energy neutrinos first; they are faster and more sizable for larger {theta}{sub 13}. They are unique of ONeMg-core supernovae, and give the possibility to test the speed of the shock wave. The time modulation of the Earth effect and its negative sign at the neutronization peak are the most robust signatures in a detector.

Lunardini, C. [Arizona State University, Tempe, Arizona 85287-1504 (United States); RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States); Mueller, B.; Janka, H.-Th. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching (Germany)

2008-07-15

349

Neon turbo-Brayton cycle refrigerator for HTS power machines  

NASA Astrophysics Data System (ADS)

We developed a prototype turbo-Brayton refrigerator whose working fluid is neon gas. The refrigerator is designed for a HTS (High Temperature Superconducting) power transformer and its cooling power is more than 2 kW at 65 K. The refrigerator has a turboexpander and a turbo-compressor, which utilize magnetic bearings. These rotational machines have no rubbing parts and no oil-components. Those make a long maintenance interval of the refrigerator. The refrigerator is very compact because our newly developed turbo-compressor is volumetrically smaller than a displacement type compressor in same operating specification. Another feature of the refrigerator is a wide range operation capability for various heat-loads. Cooling power is controlled by the input-power of the turbo-compressor instead of the conventional method of using an electric heater. The rotational speed of the compressor motor is adjusted by an inverter. This system is expected to be more efficient. We show design details, specification and cooling test results of the new refrigerator in this paper.

Hirai, Hirokazu; Hirokawa, M.; Yoshida, Shigeru; Nara, N.; Ozaki, S.; Hayashi, H.; Okamoto, H.; Shiohara, Y.

2012-06-01

350

Effect of helium-neon laser on musculoskeletal trigger points  

SciTech Connect

Cold lasers have been proposed recently as a therapeutic tool for treating a wide variety of pathological conditions, including wounds, arthritis, orthopedic problems, and pain. These proposed therapeutic effects largely have been unsubstantiated by research. A randomized, double blind study was undertaken to ascertain the effect of a helium-neon (He-Ne) laser on the resistance of areas of skin overlying musculoskeletal trigger points. These areas usually demonstrate decreased skin resistance when compared with the surrounding tissue. Thirty patients with musculoskeletal trigger points were assigned randomly to either an experimental or a placebo group. In addition to standard physical therapy, each patient received three 15-second applications of a He-Ne laser or placebo stimulation from an identical unit that did not emit a laser. The results of a two-way analysis of covariance with one repeated measure showed a statistically significant increase (p less than .007) in skin resistance. This increase in an abnormal skin resistance pattern may accompany the resolution of pathological conditions.

Snyder-Mackler, L.; Bork, C.; Bourbon, B.; Trumbore, D.

1986-07-01

351

Energy-transfer processes in neon-hydrogen mixtures excited by electron beams  

NASA Astrophysics Data System (ADS)

Energy- and charge-transfer processes in neon-hydrogen mixtures (500-1400 hPa neon and 0.001-3 hPa hydrogen partial pressures) excited by a pulsed low-energy (~10 keV) electron beam were investigated using time-resolved spectroscopy. Time spectra of the hydrogen Lyman-? line, neon excimer emission (second continuum), and neon atomic lines (3p-3s transitions) were recorded. The time-integrated intensity of the Lyman-? emission was measured for the same range of gas mixtures. It is shown that direct energy transfer from Ne2* excimers and neon atoms in the four lowest excited states as well as recombination of H3+ ions are the main channels populating atomic hydrogen in the n=2 state. A rate constant of (4.2+/-1.4)×10-11 cm3 s-1 was obtained for the charge transfer from Ne2+ ions to molecular hydrogen. A lower limit for the depopulation rate constant of Ne2* excimers by molecular hydrogen (combination of energy transfer and ionization) was found to be 1.0×10-10 cm3 s-1.

Morozov, A.; Krücken, R.; Ulrich, A.; Wieser, J.; McCarthy, T.

2005-12-01

352

NEON ground validation capabilities for airborne and space-based imagers  

NASA Astrophysics Data System (ADS)

Airborne remote sensing measurements provide the capability to quantitatively measure biochemical and biophysical properties of vegetation at regional scales, therefore complementing surface and satellite measurements. The National Ecological Observatory Network (NEON) will build three airborne systems to allow for routine coverage of NEON sites (60 sites nationally) and the capacity to respond to investigator requests for specific projects. Each airborne system will consist of an imaging spectrometer, waveform lidar and high-resolution digital camera. Remote sensing data gathered with this instrumentation needs to be quantitative and accurate in order to derive meaningful information about ecosystem properties and processes. Also, comprehensive and long-term ecological studies require these data to be comparable over time, between coexisting sensors and between generations of follow-on sensors. NEON's calibration plan for the airborne instrument suite relies on intensive laboratory, on-board, ground-based characterization as well as inter-sensor comparisons. As part of these efforts, NEON organized a pathfinder mission in September 2010 to test prototype techniques and procedures for field sampling and sensor validation. Imaging spectroscopy data from AVIRIS and waveform lidar data were acquired in addition to ecological field sampling at the Ordway-Swisher Biological Station near Gainesville, Florida. This paper presents NEON's capabilities for validation of at-sensor radiance of airborne and space-based sensors and shows results from the September 2010 pathfinder mission.

McCorkel, Joel; Kuester, Michele; Johnson, Brian R.; Kampe, Thomas U.

2011-09-01

353

[Medical supply of long flies].  

PubMed

The article presents a characteristics of main negative factors, disimproving a functional condition and working capacity of airmen in long flies: long stay in a working pose, necessity of using of summer form, of defense form and oxygen-breath means, peculiarities of eating in fly, solving of nature-imposed necessity, relative sensor deprivation, sameliness of environment, high level of noise, hypokinesia, high nervous-emotional tension in conditions of air refueling, temperature fall, difference of barometric pressure, desynchronisms. Were given practical recommendations on maintenance of functional and working capacity of members of flying staff, realizing long flies. PMID:20698321

Belevitin, A B; Tsygan, V N; Blagitin, A A; Lizogub, I N

2010-05-01

354

Investigation of the statistical nature and structure of the electrical breakdown time delay in gas diodes filled with neon  

Microsoft Academic Search

The electrical breakdown time delay in gas diodes filled by neon at the low pressures is investigated experimentally and theoretically. Experimental results are obtained measuring the characteristics of gas diodes filled by spectroscopically pure neon. In order to discard any systematic trend during the measurement procedure, checking of the measured values randomness preceded the statistical analysis of the experimental results.

Cedomir A. Maluckov; Jugoslav P. Karamarkovic; Miodrag K. Radovic

2006-01-01

355

Nuclear Moments and Differences in Mean Square Charge Radii of Short-Lived Neon Isotopes by Collinear Laser Spectroscopy  

Microsoft Academic Search

The nuclear moments and charge radii of short-lived neon isotopes were measured by the use of collinear laser spectroscopy at the on-line mass separator ISOLDE at CERN. After a general introduction the semiclassical theory of atomic spectra is given and the relevant properties are calculated for neon. The atomic physics section is followed by a description of the experimental setup

R W Geithner; R Neugart

2002-01-01

356

Neon Isotope Heterogeneity in the Terrestrial Mantle: Implication for the Acquisition of Volatile Elements in Terrestrial Planets  

Microsoft Academic Search

Neon presents a primordial isotope heterogeneity in the terrestrial mantle. Ne coming from the deep mantle is solar-like whereas neon sampled from the convective mantle is typical of Ne trapped in gas-rich meteorites,implying different acquisition processes.

B. Marty; R. Yokochi; C. J. Ballentine

2005-01-01

357

Are oxygen and neon enriched in PNe and is the current solar Ne\\/O abundance ratio underestimated?  

Microsoft Academic Search

A thorough critical literature survey has been carried out for reliable measurements of oxygen and neon abundances of planetary nebulae (PNe) and HII regions. By contrasting the results of PNe and of HII regions, we aim to address the issues of the evolution of oxygen and neon in the interstellar medium (ISM) and in the late evolutionary phases of low-

W. Wang; X.-W. Liu

2008-01-01

358

Liquid Helium and Liquid Neon-Sensitive, Low Background Scintillation Media for the Detection of Low Energy Neutrinos  

Microsoft Academic Search

The use of liquid helium and neon as scintillators for neutrino detection is investigated. Several unique properties of these cryogens make them promising candidates for real-time solar neutrino spectroscopy: large ultraviolet scintillation yields from ionizing radiation, transparency to their own scintillation light, and low levels of radioactive impurities. When neutrinos scatter from electrons in liquid helium or neon, ultraviolet light

D. N. McKinsey; J. M. Doyle

2000-01-01

359

Coupling of Retinal, Protein, and Water Dynamics in Squid Rhodopsin  

PubMed Central

The light-induced isomerization of the retinal from 11-cis to all-trans triggers changes in the conformation of visual rhodopsins that lead to the formation of the activated state, which is ready to interact with the G protein. To begin to understand how changes in the structure and dynamics of the retinal are transmitted to the protein, we performed molecular dynamics simulations of squid rhodopsin with 11-cis and all-trans retinal, and with two different force fields for describing the retinal molecule. The results indicate that structural rearrangements in the binding pocket, albeit small, propagate toward the cytoplasmic side of the protein, and affect the dynamics of internal water molecules. The sensitivity of the active-site interactions on the retinal force-field parameters highlights the coupling between the retinal molecule and its immediate protein environment.

Jardon-Valadez, Eduardo; Bondar, Ana-Nicoleta; Tobias, Douglas J.

2010-01-01

360

[Immunoactive peptide obtained from the optical ganglia of squid].  

PubMed

The data on the effect of a peptide from the squid optic ganglia named gangliin on some parameters of animal natural resistance are presented. It was shown that the prophylactic use of the peptide in mice 24 hours before their contamination with the lethal dose of E. coli protected 40 to 60 per cent of the animals from death. Gangliin accelerated elimination of E. coli from the host and increased the absorptive and digestive activity of the macrophages and polymorphonuclear leukocytes. With the use of gangliin it was possible to correct the phagocytosis defects in infectious processes having the phagocytic protection mechanism. Moreover, gangliin was supposed to be efficient in control of long-term persistence of various microbes in the cells of the system of mononuclear phagocytes. PMID:1953188

Besednova, N N; Zaporozhets, T S; Sergienko, A K; Krylova, N V; Epshte?n, L M; Borovskaia, G A

1991-07-01

361

SQUID-Detected Microtesla MRI in the presence of Metal  

SciTech Connect

In magnetic resonance imaging (MRI) performed at fields of 1 T and above, the presence of a metal insert can distort the image because of susceptibility differences within the sample and modification of the radiofrequency fields by screening currents. Furthermore, it is not feasible to perform nuclear magnetic resonance (NMR) spectroscopy or acquire a magnetic resonance image if the sample is enclosed in a metal container. Both problems can be overcome by substantially lowering the NMR frequency. Using a microtesla imaging system operating at 2.8 kHz, with a superconducting quantum interference device (SQUID) as the signal detector, we have obtained distortion-free images of a phantom containing a titanium bar and three-dimensional images of an object enclosed in an aluminum can; in both cases high-field images are inaccessible.

Moessle, Michael; Han, Song-I.; Myers, Whittier; Lee, Seung-Kyun; Kelso, Nathan; Hatridge, Michael; Pines, Alexander; Clarke, John

2006-09-06

362

SQUID measurements for thermal aging of stator windings  

NASA Astrophysics Data System (ADS)

Conventional non-destructive diagnostic tests for aging of dielectric insulation on high voltage cables and stator windings are limited to measurements of lumped electrical parameters. Commonly used step voltage tests may lead to breakdown of the insulation and damage to the system. A map of spatial distribution of the electrical properties of the cable may provide the information about the age-related failure. Our approach uses a Superconducting Quantum Interference Device (SQUID) magnetometer to map the magnetic field due to charging current through the cable. We have performed a series of experiments which demonstrate that we can image magnetically the distribution of charging currents and the perturbations in this distribution that result from localized changes in dielectric constant, and we can discriminate thermally aged stator windings from new ones. .

Ma, Yu Pei; Wikswo, John P.; Fitzpatrick, Gerald

2001-04-01

363

Spawning strategy in Atlantic bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)  

NASA Astrophysics Data System (ADS)

This study aimed to determine the spawning strategy in the Atlantic bobtail squid Sepiola atlantica, in order to add new information to the knowledge of its reproductive strategy. A total of 12 females that spawned in aquaria were examined. Characteristics of the reproductive traits and egg clutches were similar to those of other known Sepiolidae. Clutch size varied from 31 up to 115 eggs. Females of this species had incorporated up to 1.58 times of their body weight into laid eggs. The size of laid eggs showed a positive correlation with maternal body size, supporting the idea that female size is a determinant of egg size. Our data suggest that S. atlantica is an intermittent terminal spawner , and that its spawning strategy comprises group-synchronous ovary maturation, multiple egg laying, and deposition of egg clutches in different locations. The obtained data provide insights for future comparative studies on reproductive allocation.

Rodrigues, Marcelo; Garcí, Manuel E.; Troncoso, Jesús S.; Guerra, Ángel

2011-03-01

364

Relativistic dynamics of domain wall in one-dimensional SQUID array  

NASA Astrophysics Data System (ADS)

We investigate the dynamics of a domain wall in a one-dimensional array of superconducting quantum interference device (SQUID) composed of three conventional Josephson junctions and a ?-junction. The domain wall is formed between two domains with oppositely circulating current through the SQUID loop. It is shown that the SQUIDs in this array can be approximately described by a double sine-Gordon (DSG) model which obeys Einstein's special theory of relativity. We conduct numerical simulations of a discrete DSG equation and show that the domain wall propagates solitonically through the SQUID array and exhibits quasi-relativistic behavior, such as the Lorentz contraction and the relativistic time dilation, which agrees reasonably well with the predictions from a relativistic equation of motion of a particle, whose rest mass is extremely small compared to that of a single electron.

Nishida, Munehiro; Aoki, Yuushi; Fujii, Toshiyuki

2012-12-01

365

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

PubMed Central

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.

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

2012-01-01

366

75 FR 5537 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013

...Fisheries; Specifications and Management Measures AGENCY: National Marine Fisheries Service...implements 2010 specifications and management measures for Atlantic mackerel, squid, and butterfish...These specifications and management measures promote the utilization and...

2010-02-03

367

Rapid changes in intracellular free calcium concentration. Detection by metallochromic indicator dyes in squid giant axon.  

PubMed Central

The metallochromic indicator dyes, arsenazo III and chlorophosphonazo III, were used in squid giant axons to detect rapidly the very small influxes of calcium that occur as a result of changes of membrane potential.

Brown, J E; Cohen, L B; De Weer, P; Pinto, L H; Ross, W N; Salzberg, B M

1975-01-01

368

Ionic currents in isolated and in situ squid Schwann cells  

PubMed Central

Ionic currents from Schwann cells isolated enzymatically from the giant axons of the squids Loligo forbesi, Loligo vulgaris and Loligo bleekeri were compared with those obtained in situ. Macroscopic and single channel ionic currents were recorded using whole-cell voltage and patch clamp. In the whole-cell configuration, depolarisation from negative holding potentials evoked two voltage-dependent currents, an inward current and a delayed outward current. The outward current resembled an outwardly rectifying K+ current and was activated at ?40 mV after a latent period of 5-20 ms following a step depolarisation. The current was reduced by externally applied nifedipine, Co2+ or quinine, was not blocked by addition of apamin or charibdotoxin and was insensitive to externally applied l-glutamate or acetylcholine. The voltage-gated inward current was activated at ?40 mV and was identified as an L-type calcium current sensitive to externally applied nifedipine. Schwann cells were impaled in situ in split-open axons and voltage clamped using discontinuous single electrode voltage clamp. Voltage dependent outward currents were recorded that were kinetically identical to those seen in isolated cells and that had similar current-voltage relations. Single channel currents were recorded from excised inside-out patches. A single channel type was observed with a reversal potential close to the equilibrium potential for K+ (EK) and was therefore identified as a K+ channel. The channel conductance was 43.6 pS when both internal and external solutions contained 150 mm K+. Activity was weakly dependent on membrane voltage but sensitive to the internal Ca2+ concentration. Activity was insensitive to externally or internally applied l-glutamate or acetylcholine. The results suggest that calcium channels and calcium-activated K+ channels play an important role in the generation of the squid Schwann cell membrane potential, which may be controlled by the resting intracellular Ca2+ level.

Inoue, Isao; Tsutsui, Izuo; Joan Abbott, N; Brown, Euan R

2002-01-01

369

Solar wind neon from Genesis: implications for the lunar noble gas record.  

PubMed

Lunar soils have been thought to contain two solar noble gas components with distinct isotopic composition. One has been identified as implanted solar wind, the other as higher-energy solar particles. The latter was puzzling because its relative amounts were much too large compared with present-day fluxes, suggesting periodic, very high solar activity in the past. Here we show that the depth-dependent isotopic composition of neon in a metallic glass exposed on NASA's Genesis mission agrees with the expected depth profile for solar wind neon with uniform isotopic composition. Our results strongly indicate that no extra high-energy component is required and that the solar neon isotope composition of lunar samples can be explained as implantation-fractionated solar wind. PMID:17110575

Grimberg, Ansgar; Baur, Heinrich; Bochsler, Peter; Bühler, Fritz; Burnett, Donald S; Hays, Charles C; Heber, Veronika S; Jurewicz, Amy J G; Wieler, Rainer

2006-11-17

370

A stochastic, local mode study of neon-liquid surface collision dynamics.  

PubMed

Equations of motion for a fast, light rare gas atom passing over a liquid surface are derived and used to infer the dynamics of neon collisions with squalane and perfluorinated polyether surfaces from experimental data. The equations incorporate the local mode model of a liquid surface via a stochastic process and explicitly account for impulsive collisional energy loss to the surface. The equations predict angular distributions for scattering of neon that are in good quantitative agreement with experimental data. Our key dynamical conclusions are that experimental angular distributions derive mainly from local mode surface topography rather than from structural features of individual surface molecules, and that the available data for these systems can be accounted for almost exclusively by single collisions between neon atoms and the liquid surface. PMID:21042647

Packwood, Daniel M; Phillips, Leon F

2010-11-01

371

Magnetic nanoparticle relaxation measured by a low-Tc SQUID system  

Microsoft Academic Search

A low-Tc SQUID system was developed for measuring magnetic relaxation of polymer-coated magnetic nanoparticles (MNPs) in a liquid carrier (e.g. water). The system consists of two low-Tc SQUIDs which are electronically combined to form an axial gradiometer using high-bandwidth directly coupled FLL electronics. The system is operated in a magnetically shielded room. The magnetic relaxation of the investigated MNPs in

A. Haller; S. Hartwig; H. Matz; J. Lange; T. Rheinländer; R. Kötitz; W. Weitschies; L. Trahms

1999-01-01

372

Use of a DC SQUID receiver preamplifier in a low field MRI system  

Microsoft Academic Search

We have used tuned receiver coils coupled to a dc SQUID preamplifier in a small scale magnetic resonance imaging (MRI) system operating at 425 kHz (B0=0.01 T). The coil and SQUID are cooled to 4.2 K in a modified biomagnetic cryostat. The modifications provide transparency to rf signals originating outside the cryostat while maintaining an acceptably low liquid helium boiloff

H. C. Seton; D. M. Bussell; J. M. S. Hutchison; D. J. Lurie

1995-01-01

373

Cryogenic current comparators with optimum SQUID readout for current and resistance quantum metrology  

Microsoft Academic Search

This thesis describes the development of several systems based on the Cryogenic Current Comparator with optimum SQUID readout, for current and resistance metrology applications. the CCC-SQUID is at present the most accurate current comparator available. A (type I) CCC consists basically of a superconducting tube containing two sets of windings N1 and N2, carrying the two currents I1 and I2

María Elena Bartolomé Porcar

2002-01-01

374

Characterizations of Chitosan Sponges Prepared from Shrimp Shell (Penaeus monodon) and Squid Pen (Loligo formosana)  

Microsoft Academic Search

Chitosan is a deacethylated product of chitin which is a major component of prawn shell and squid pen. Structurally, the linear polymer chains of chitin from prawn shell are arranged by anti-parallel fashion, ? -form while the chains from squid pen are arranged by parallel fashion, -form. Since the compatible biopolymers exhibit anti-bacterial, anti-fungal, enhance wound healing and hemostatic activities,

Ausa Chandumpai; Monta Jumreanrak; Kongpat Pongpaiboon; Waykin Nopanitaya

375

High-performance high-Tc SQUID sensors for multichannel systems in magnetically disturbed environment  

Microsoft Academic Search

We have fabricated and characterized high-Tc SQUID sensors that are suited for operation in multichannel systems in magnetically disturbed environment. Utilizing the superior properties of our 30° SrTiO3 bicrystal junctions, we are able to fabricate high-performance single-layer direct-coupled SQUID magnetometers. System noise levels down to 24 fT Hz-1\\/2 and typical 1\\/f corners of 4 Hz-1\\/2 were obtained for devices having

F. Ludwig; J. Beyer; D. Drung; S. Bechstein; T. Schurig

1999-01-01

376

Bi-SQUIDs with submicron cross-type Josephson tunnel junctions  

Microsoft Academic Search

We present and discuss results for the experimental evaluation of bi-SQUIDs with shunted submicron cross-type Josephson tunnel junctions characterized by low capacitance. Such a technology, meant for SQUID sensors, was developed to enable unshielded operation of the sensors and to avoid unwanted flux trapping. The obtained voltage response swing is as high as 60 µV. The observed differences between the

A Sharafiev; I Soloviev; V Kornev; M Schmelz; R Stolz; V Zakosarenko; S Anders; H-G Meyer

2012-01-01

377

Characterization of the bacterial diversity in Indo-West Pacific loliginid and sepiolid squid light organs.  

PubMed

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

Guerrero-Ferreira, Ricardo; Gorman, Clayton; Chavez, Alba A; Willie, Shantell; Nishiguchi, Michele K

2012-08-12

378

Flexible Robot Manipulators and Grippers: Relatives of Elephant Trunks and Squid Tentacles  

Microsoft Academic Search

\\u000a Elephants and squids have continuously flexible appendages that are well adapted for manipulating and gripping. In this paper\\u000a we briefly review the overall structural forms and motions of elephant trunks and squid tentacles. We then discuss how we\\u000a incorporated some of their biological characteristics in the design of a flexible arm manipulator with open loop control (Part\\u000a 1) and in

J. F. Wilson; D. Li; Z. Chen; R. T. George

379

Detection of Fatigue Damage Prior to Crack Initiation withScanning SQUID Microscopy  

SciTech Connect

The remanence fields of fatigued ferritic steel specimens were measured using a scanning microscope based on a high transition temperature Superconducting Quantum Interference Device (SQUID). The results show an overall increase of remanence until dislocation density saturates and an additional local remanence increase after saturation during cyclic loading. Because of the combined magnetic and spatial resolution of the SQUID microscope, these local changes of dislocation structures can be detected before a crack actually initiates, and identify the sites where crack nucleation will occur.

Lee, Tae-Kyu; Morris Jr., J.W.; Lee, Seungkyun; Clarke, John

2005-11-07

380

SQUID measurements of magnetic vortices in very underdoped yttrium-barium-copper-oxide  

Microsoft Academic Search

This dissertation describes the first demonstration of a scanning Superconducting QUantum Interference Device (SQUID) susceptometer---a new tool for the study of local magnetic properties of materials---and applies it to a series of studies of vortices in the cuprate superconductor YBa2Cu 3O6+x. The susceptometer is comprised of a scanning SQUID with an 8mum pickup loop and an integrated 21mum diameter field

Brian Willard Gardner

2005-01-01

381

High-temperature single-layer SQUID gradiometers with long baseline and parasitic effective area compensation  

Microsoft Academic Search

First-order HTS SQUID gradiometers were fabricated on 30 × 10 mm2 bicrystal substrates. These devices have a baseline of 13 mm, intrinsic balance levels of ~1\\/700 and a typical gradient sensitivity at 1 kHz of 79 fT cm-1 Hz-1\\/2. A two-SQUID coupling scheme is discussed that further enhances the device's ability to reject uniform fields.

C. M. Pegrum; A. Eulenburg; E. J. Romans; C. Carr; A. J. Millar; G. B. Donaldson

1999-01-01

382

Phylogeny and Historical Biogeography of the Loliginid Squids (Mollusca: Cephalopoda) Based on Mitochondrial DNA Sequence Data  

Microsoft Academic Search

The cephalopod taxon Loliginidae (Cephalopoda: Myopsida) is a species-rich group of tropical and temperate shallow-water squids, many of which are commercial fisheries objects and neurophysiological research organisms. The worldwide distribution of these squids could make Loliginidae a useful case study in shallow-water marine biogeography, but the phylogeny of the group is unknown. To clarify loliginid phylogeny, regions of two mitochondrial

Frank E. Anderson

2000-01-01

383

Trace metal levels in the raw and tinned squid Loligo patagonica.  

PubMed

The cadmium, silver, lead, copper, zinc, manganese, iron and mercury levels in the edible and inedible tissues of raw and tinned Loligo patagonica squid were determined using flame atomic absorption spectrometry (AAS) for Cd, Ag, Pb, Cu, Zn, Mn and Fe and cold-vapour AAS for Hg. The mean values obtained relative to the wet-weight (mg/kg) for the edible parts (skinless mantle, arms and crone and fin) of the raw and tinned (mantle) squid, and in whole raw and tinned squid, were: 0.32, 0.32, 0.31, 4.3, 3.2 and 3.0 for Cd, 1.0, 0.34, 0.77, 0.27, 0.59 and 0.44 for Pb, 7.8, 5.5, 11, 33, 22 and 26 for Cu, 12, 13, 12, 19, 16 and 17 for Zn, 0.38, 0.45, 0.48, 0.75, 0.48 and 0.73 for Mn and 2.7, 2.3, 3.4, 3.4, 2.2 and 9.4 for Fe, respectively. The content of silver and mercury in the mantle of the tinned squid were 0.18 and 0.012 mg/kg, respectively. As a consequence of whole squid processing, highly elevated levels of cadmium, and also somewhat higher levels of some of the other trace metals, were found in the edible parts of the tinned squid. The content of cadmium in the edible parts of the squid in all instances exceed, and for edible parts of the tinned whole squid considerably exceed, the proposed tolerance limit for cadmium in fishery products (0.05 mg/kg). PMID:2792467

Falandysz, J

384

Electronic gradiometry for NDE in an unshielded environment with stationary and moving HTS SQUIDs  

Microsoft Academic Search

Difficulties in the fabrication of multilayer high-temperature superconductor (HTS) devices have led to recent interest in the use of simpler HTS SQUID magnetometers in electronic gradiometers. One application of such systems is electromagnetic non-destructive evaluation. We have developed a prototype two-SQUID system and we present recent results in this paper. We first demonstrate the level of interference suppression by comparing

C. Carr; A. Cochran; J. Kuznik; D. Mc A. McKirdy; G. B. Donaldson

1996-01-01

385

A high temperature superconductor dc SQUID planar gradiometer measurement system for routine inspections  

Microsoft Academic Search

We have developed a high temperature superconductor (HTS) dc SQUID gradiometric measurement system for routine applications in non-destructive evaluations. Low values of the white flux noise and white field gradient noise were measured for gradiometers operating at 77 K. Low frequency noise was suppressed using an ac bias technique, even in a magnetically unshielded environment. First-order planar dc SQUID flip-chip

M. I. Faley; U. Poppe; V. Yu Slobodchikov; Yu V. Maslennikov; K. Urban

2004-01-01

386

Defect profiles identification of conducting materials using HTS-SQUID gradiometer with multiple frequencies  

NASA Astrophysics Data System (ADS)

This paper is concerned with a quantitative nondestructive evaluation of conducting materials using high temperature superconducting quantum interference devices (HTS-SQUIDs). A mathematical model of the nondestructive evaluation system is described by a three dimensional eddy current model. The forward analyses using the finite element model are implemented for conducting materials with a depth-varying crack. A computational method based on the genetic algorithm is proposed for recovering internal defect profiles with HTS-SQUID data. .

Kojima, F.; Kawai, R.; Kasai, N.; Hatsukade, Y.

2001-04-01

387

Effects of Electromagnetic Radiation From Digital Wireless Telephone Frequencies on a Double Relaxation Oscillation SQUID  

Microsoft Academic Search

In this paper, the effects of electromagnetic fields from the frequency band of digital wireless telephones on a superconducting quantum interference device (SQUID) were experimentally investigated. A first-order planar gradiometer based on the double relaxation oscillation SQUID (DROS) was operated without low-frequency magnetic shielding, and was exposed to radiated electromagnetic fields in the frequency range of 300 MHz-2 GHz. The

Tae-Weon Kang; Yong-Ho Lee; Sung-Ho Won; Jin-Mok Kim; Ki-Dam Kim

2009-01-01

388

Optimization of NDE Characterization Parameters for a RF-SQUID Based System Using FEM Analysis  

Microsoft Academic Search

We have investigated the dependence of the optimal non destructive evaluation (NDE) characterization on different excitation parameters in an eddy current SQUID NDE system for samples with known flaw depths. The considered parameters in our study include the configuration of the excitation-coil and its current frequency. The system is based on a high-TC YBCO gradiometer RF-SQUID sensor with a flux

Mehdi Fardmanesh; Farrokh Sarreshtedari; Arash Pourhashemi; Elnaz Ansari; Mohammad A. Vesaghi; Juergen Schubert; Marko Banzet; Hans-Joachim Krause

2009-01-01

389

Studies of Magnetic Vortices in Superconductor Networks and Clusters by Scanning SQUID Microscopy  

Microsoft Academic Search

We have developed a Scanning SQUID Microscope (SSM) to study the configuration of trapped magnetic vortices in two-dimensional superconductor arrays and clusters. The SSM scans a dc SQUID detector over the array surface, achieving better than 10mum spatial resolution over a scan range up to 1cm x 1cm and a magnetic flux sensitivity of about 10^{-4}Phi_ {rm O}. We have

Lan Ngoc Vu

1993-01-01

390

NOVA: Spies that Fly  

NSDL National Science Digital Library

Spies that Fly is a NOVA episode that originally aired in January 2003. This page of the television broadcast's online companion provides a fascinating historical account of unmanned aerial vehicles (UAV's). It will probably come as a surprise that the earliest UAV listed on this site was flown over four decades before the first manned airplane took off. From their modest beginnings, UAV's have evolved into extremely high tech instruments; the six-inch Black Widow UAV is one of the most extraordinary items described online. The Web site also shows some of the records for UAV technology.

391

See How It Flies  

NSDL National Science Digital Library

This website contains an online book about the physics of airplanes and flight. Its main topics cover perceptions of pilots, procedures for piloting, and the science principles behind flying. This book is intended to appeal to pilots and everyone else who is interested in how airplanes behave. The idea is to concentrate on ideas that are useful in the cockpit, and to explain them as clearly as possible. In addition to describing how the airplane behaves, this book describes in some detail why the airplane behaves that way.

Denker, John

2010-12-15

392

Flying wires at Fermilab  

SciTech Connect

Transverse beam profile measurement systems called ''Flying Wires'' have been installed and made operational in the Fermilab Main Ring and Tevatron accelerators. These devices are used routinely to measure the emittance of both protons and antiprotons throughout the fill process, and for emittance growth measurements during stores. In the Tevatron, the individual transverse profiles of six proton and six antiproton bunches are obtained simultaneously, with a single pass of the wire through the beam. Essential features of the hardware, software, and system operation are explained in the rest of the paper. 3 refs., 4 figs.

Gannon, J.; Crawford, C.; Finley, D.; Flora, R.; Groves, T.; MacPherson, M.

1989-03-01

393

Squid-Derived Chitin Oligosaccharides Are a Chemotactic Signal during Colonization by Vibrio fischeri  

PubMed Central

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.

Schaefer, Amy L.; Brennan, Caitlin A.; Heath-Heckman, Elizabeth A. C.; DeLoney-Marino, Cindy R.; McFall-Ngai, Margaret J.

2012-01-01

394

Effect of radiofrequency pumping conditions on Josephson generation frequency in a resistive SQUID  

SciTech Connect

The dependence on the rf pumping power of the Josephson generation frequency f/sub J/ in a hysteresis SQUID with a single weak contact is detected and studied experimentally. The dependence shows up in the first plateau of the current-voltage characteristic of the oscillatory circuit associated with the resistive SQUID. When a dc current I/sub 0/ was transmitted through the SQUID in the experiments, the frequency f/sub J/ was found to be less at the edges of the plateau than in the middle, with the difference increasing at smaller currents I/sub 0/. The length of the nonlinear initial part of the characteristic f/sub J/(I/sub 0/) is greater at the edges of the plateau than at the center. The shape of the envelope of the amplitude-modulated voltage in the circuit associated with the resistive SQUID also depends on the rf pumping power and is not a symmetric triangle at the edges of the plateau. These features of the SQUID are attributed to the dependence of the low-frequency component of the current amplitude (average current) in a resistive SQUID on the rf pump power, and do not indicate a violation of the fundamental Josephson relation for the generation frequency when there is weak coupling. The above dependence of f/sub J/ on I/sub 0/ must be allowed for in measuring infralow voltages, particularly in noise thermometry for temperatures in the 10/sup -3/ K range.

Vasil'ev, B.V.; Krivoi, G.S.

1982-02-01

395

Multiplexed HTS rf SQUID magnetometer array for eddy current testing of aircraft rivet joints  

NASA Astrophysics Data System (ADS)

Using three rf SQUID magnetometers, a multiplexed SQUID array was implemented. The SQUIDs are positioned in line with 7 mm spacing and operated using one feedback electronics with sequential read out demodulation at different radio frequencies (rf). The cross-talk between SQUID channels was determined to be negligible. To show the performance of the SQUID array, eddy current (EC) measurements of aluminum aircraft samples in conjunction with a differential (double-D) EC excitation and lock-in readout were carried out. With computer-controlled continuous switching of the SQUIDs during the scan, three EC signal traces of the sample are obtained simultaneously. We performed measurements with an EC excitation frequency of 135 Hz to localize an artificial crack (sawcut flaw) of 20 mm length in an aluminum sheet with 0.6 mm thickness. The flaw was still detected when covered with aluminum of up to 10 mm thickness. In addition, measurements with varying angles between scanning direction and flaw orientation are presented. .

Gärtner, S.; Krause, H.-J.; Wolters, N.; Lomparski, D.; Wolf, W.; Schubert, J.; Kreutzbruck, M. V.; Allweins, K.

2002-05-01

396

Biodiversity among luminescent symbionts from squid of the genera Uroteuthis, Loliolus and Euprymna (Mollusca: Cephalopoda)  

PubMed Central

Luminescent bacteria in the family Vibrionaceae (Bacteria: ?-Proteobacteria) are commonly found in complex, bilobed light organs of sepiolid and loliginid squids. Although morphology of these organs in both families of squid is similar, the species of bacteria that inhabit each host has yet to be verified. We utilized sequences of 16S ribosomal RNA, luciferase ?-subunit (luxA) and the glyceraldehyde-3-phosphate dehydrogenase (gapA) genes to determine phylogenetic relationships between 63 strains of Vibrio bacteria, which included representatives from different environments as well as unidentified luminescent isolates from loliginid and sepiolid squid from Thailand. A combined phylogenetic analysis was used including biochemical data such as carbon use, growth and luminescence. Results demonstrated that certain symbiotic Thai isolates found in the same geographic area were included in a clade containing bacterial species phenotypically suitable to colonize light organs. Moreover, multiple strains isolated from a single squid host were identified as more than one bacteria species in our phylogeny. This research presents evidence of species of luminescent bacteria that have not been previously described as symbiotic strains colonizing light organs of Indo-West Pacific loliginid and sepiolid squids, and supports the hypothesis of a non-species-specific association between certain sepiolid and loliginid squids and marine luminescent bacteria.

Guerrero-Ferreira, R. C.; Nishiguchi, M. K.

2012-01-01

397

A Numerical Treatment of the Rf SQUID: I. General Properties andNoise Energy  

SciTech Connect

We investigate the characteristics and noise performance of rf Superconducting Quantum Interference Devices (SQUIDs) by solving the corresponding Langevin equations numerically and optimizing the model parameters with respect to noise energy. After introducing the basic concepts of the numerical simulations, we give a detailed discussion of the performance of the SQUID as a function of all relevant parameters. The best performance is obtained in the crossover region between the dispersive and dissipative regimes, characterized by an inductance parameter {beta}{prime}{sub L} {triple_bond} 2{pi}LI{sub 0}/{Phi}{sub 0} {approx} 1; L is the loop inductance, I{sub 0} the critical current of the Josephson junction, and {phi}{sub 0} the flux quantum. In this regime, which is not well explored by previous analytical approaches, the lowest (intrinsic) values of noise energy are a factor of about 2 above previous estimates based on analytical approaches. However, several other analytical predictions, such as the inverse proportionality of the noise energy on the tank circuit quality factor and the square of the coupling coefficient between the tank circuit and the SQUID loop, could not be well reproduced. The optimized intrinsic noise energy of the rf SQUID is superior to that of the dc SQUID at all temperatures. Although for technologically achievable parameters this advantage shrinks, particularly at low thermal fluctuation levels, we give an example for realistic parameters that leads to a noise energy comparable to that of the dc SQUID even in this regime.

Kleiner, Reinhold; Koelle, Dieter; Clarke, John

2007-01-15

398

Effect of voltage source internal resistance on the SQUID bootstrap circuit  

NASA Astrophysics Data System (ADS)

The voltage-biased SQUID bootstrap circuit (SBC) is suitable for achieving simple and low-noise direct readout of dc SQUIDs. In practice, an ideal voltage bias is difficult to realize because of non-zero internal resistance Rin of the bias voltage source. In order to clearly observe the influence of Rin on the SBC parameters (namely the flux-to-current transfer coefficient (?I/??)SBC and the dynamic resistance Rd(SBC)) and the noise performance, we introduced an additional adjustable resistor Rad at room temperature to simulate a variable Rin between the SQUID and the preamplifier. We found that the measured SQUID flux noise does not rise, even though Rad increases significantly. This result demonstrates that a highly resistive connection can be inserted between the liquid-helium-cooled SQUID and the room-temperature readout electronics in the SBC scheme, thus reducing the conductive heat loss of the system. This work will be significant for developing multichannel SBC readout systems, e.g. for biomagnetism, and systems using SQUIDs as amplifiers, for example, in TES-array readout.

Dong, Hui; Zhang, Guofeng; Wang, Yongliang; Zhang, Yi; Xie, Xiaoming; Krause, Hans-Joachim; Braginski, Alex I.; Offenhäusser, Andreas

2012-01-01

399

Development of a HTS SQUID module for use with an external pickup coil  

NASA Astrophysics Data System (ADS)

We have developed HTS SQUID modules applicable to various systems, such as nondestructive evaluation and low-field NMR/MRI systems. The SQUID module consists of a directly coupled HTS planar gradiometer and a HTS multi-turn input coil, which are fabricated on separate substrates and stacked with a flip-chip configuration. Two types of input coils, 26-turns and 59-turns, are fabricated. The SQUID module is mounted on a printed circuit board with large electrodes for soldering to the external pickup coil. The mutual inductances between the input coil and SQUID varied from 0.5 to 2.3 nH, depending on the number of turns of the input coil and the inductance of the SQUID. The SQUID modules with an external pickup coil made of normal metal showed a lower cut-off frequency of 45 Hz and a field noise as low as 35 fT Hz-1/2 (>4 kHz).

Tsukamoto, A.; Adachi, S.; Oshikubo, Y.; Tanabe, K.; Enpuku, K.

2013-01-01

400

Studies on two calcium-binding proteins from squid optic lobe  

SciTech Connect

Investigations focused on the physicochemical and functional properties of squid calcium-binding protein (SCaBP) and squid calmodulin (SCaM). The physiochemical studies included characterization of Ca/sup 2 +/- and Mg/sup 2 +/-binding properties, and the effects of metal ion-binding on protein conformation. These studies were performed using various ionic conditions, including those physiological for the squid. Ca/sup 2 +/-binding by SCaBP, SCaM, and bovine brain calmodulin (BCaM) (for comparison) was measured by equilibrium dialysis. All three proteins bound 4 Ca/sup 2 +/ per mol protein under each set of ionic conditions. Under conditions physiological for the squid, both the squid proteins bound Ca/sup 2 +/ over a similar range of free Ca/sup 2 +/ concentrations. Ca/sup 2 +/ - and Mg/sup 2 +/-induced changes in the conformation of the proteins were studied by polyacrylamide gel electrophoresis, fluphenazine-Sepharose affinity chromatography, and ultraviolet absorption difference spectroscopy. The functional studies focused on the identification of squid optic lobe proteins which interacted with SCaBP and SCaM in a Ca/sup 2 +/- dependent manner. These proteins were identified by SCaBP- and SCaM-Sepharose affinity chromatography, an immunoblotting technique using a polyclonal anti-SCaBP antibody, and a /sup 125/I-calmodulin overlay procedure.

Sheldon, A.

1988-01-01

401

Single SQUID multiplexer for arrays of voltage-biased superconducting bolometers  

SciTech Connect

We describe a frequency domain superconducting quantum interference device (SQUID) multiplexer which monitors a row of low-temperature sensors simultaneously with a single SQUID. Each sensor is ac biased with a unique frequency and all the sensor currents are added in a superconducting summing loop. A single SQUID measures the current in the summing loop, and the individual signals are lock-in detected after the room temperature SQUID electronics. The current in the summing loop is nulled by feedback to eliminate direct crosstalk. In order to avoid the accumulation of Johnson noise in the summing loop, a tuned bandpass filter is inserted in series with each sensor. For a 32-channel multiplexer for Voltage-biased Superconducting Bolometer (VSB) with a time constant {approx}1msec, we estimate that bias frequencies in the range from {approx}500kHz to {approx}600kHz are practical. The major limitation of our multiplexing scheme is in the slew rate of a readout SQUID. We discuss a ''carrier nulling'' technique which could be used to increase the number of sensors in a row or to multiplex faster bolometers by reducing the required slew rate for a readout SQUID.

Yoon, Jongsoo; Clarke, John; Gildemeister, J.M.; Lee, Adrian T.; Myers, M.J.; Richards, P.L.; Skidmore, J.T.; Spieler, H.G.

2001-08-20

402

The Virtual Transgenic Fly Lab  

NSDL National Science Digital Library

The lab will familiarize you with the science and techniques used to make transgenic flies. Transgenic organisms, which contain DNA that is inserted experimentally, are used to study many biological processes. In this lab, you will create a transgenic fly to study circadian rhythms.

Peter J. Bruns, Ph.D. (Howard Hughes Medical Institute;)

2008-04-16

403

Flying hot-wire anemometry  

Microsoft Academic Search

A flying hot-wire arrangement has been developed for the measurement of the velocity characteristics of the flow around airfoils, and particularly in regions where negative values of instantaneous velocity occur. The mechanism and signal processing system are described and appraised by comparing stationary and flying wire measurements obtained in the trailing edge region of a flap at an angle of

B. E. Thompson; J. H. Whitelaw

1984-01-01

404

Large sticky traps for capturing house flies and stable flies in dairy calf greenhouse facilities.  

PubMed

Large sticky traps were evaluated for stable fly, Stomoxys calcitrans (L.), and house fly, Musca domestica L., (Diptera: Muscidae) capture under field conditions in 5 dairy calf greenhouse facilities in New York. The farm with the highest stable fly capture had the highest house fly capture, and the farm with the lowest stable fly capture had the lowest house fly capture, suggesting that fly management practices greatly influenced trap captures. In general, stable fly populations, as reflected by increased trap capture, generally rose during the summer. Numbers of flies counted on calves did not increase, however, suggesting that the traps greatly reduced the potential stable fly pressure on the calves as the fly population increased. Estimated number of stable flies and house flies captured during this 10-wk study exceeded 142,000 and 900,000, respectively. Producers were generally pleased with the trap performance and most felt that these traps reduced flies in their calf greenhouses to acceptable levels. PMID:15591381

Kaufman, P E; Rutz, D A; Frisch, S

2005-01-01

405

Interatomic Coulombic decay of fixed-in-space neon dimers  

NASA Astrophysics Data System (ADS)

The detailed theoretical and experimental analysis of the angular distributions of electrons from interatomic Coulombic decay (ICD) of the Ne dimer in the molecular frame is performed. In the initial state the doubly charged dimer ion has one 2s vacancy and one 2p vacancy on one atom. After the ICD process the neutral neon atom is ionized and the triply charged molecular ion dissociates into singly and doubly charged atomic ions, Ne2+(2p-2)+Ne+(2p-1). From the coincident measurement of kinetic energy release (KER) of the ions and the ICD electron the decay channel can be identified unambiguously. The most detailed experimental data have been obtained for the singlet dicationic state Ne2+(2p-2)[1D]. Different KER energies correspond to different internuclear distances at which the ICD process takes place. In experiment the data have been presented for three regions of KER energies, and the corresponding calculations have been performed for three fixed internuclear distances. In calculations we imply that all the electrons in Ne2 to a good approximation are localized. However, we need to retain the molecular character of the dimer wave functions which opens the possibility for the ICD process. To do it, we calculate at first the Hartree-Fock ground state wave functions of the neutral Ne2 dimer using the standard procedure for homonuclear diatomic molecules corresponding to the D?h symmetry group. For the doubly charged ion Ne22+ with two vacancies on one atom the symmetry is lowered to C?v, and we are looking now for the set of one-electron Hartree-Fock wave functions which are localized either on the left or on the right atom as a linear combination of symmetry-adopted wave functions. The theory correctly reproduces the experimental data and predicts the sharp variation of the angular distributions as a function of internuclear distance.

Semenov, S. K.; Kreidi, K.; Jahnke, T.; Weber, Th.; Havermeier, T.; Grisenti, R. E.; Liu, X.; Morisita, Y.; Schmidt, L. Ph. H.; Schöffler, M. S.; Odenweller, M.; Neumann, N.; Foucar, L.; Titze, J.; Ulrich, B.; Sturm, F.; Kim, H. K.; Ueda, K.; Czasch, A.; Jagutzki, O.; Cherepkov, N. A.; Dörner, R.

2012-04-01

406

Electron thermalization in gases. II. Neon, argon, krypton, and xenon  

NASA Astrophysics Data System (ADS)

Following the theoretical procedure outlined in an earlier paper [J. Chem. Phys. 72, 1657 (1980)], hereinafter referred as I, the present work in an extension to the other rare gases. The following quantities are computed and evaluated: thermalization time and the position distribution at thermalization, time-dependent relaxation rates and evolutions of the directed velocity, width of the positional distribution, and the diffusion coefficient. A Newtonian cooling law has been demonstrated when the effective electron temperature is close to the gas temperature with an equation for the relaxation time of the excess electron temperature. Weighted moments of the form Mn=T have been calculated for n=1 to 10, where ?m is the momentum transfer cross section and the symbol <--->T denotes averaging with respect to the equilibrium electron velocity distribution at T. The fifth and the seventh moments are related, respectively, to the energy loss rate when is >>T and to the Newtonian cooling rate then ?T. As in I the thermalization parameters are largely independent of initial velocity if the initial electron kinetic energy is much greater than that for the Ramsauer minimum (Ar, Kr, and Xe). Otherwise the thermalization time is considerably reduced. A somewhat analogous situation in neon is attributed to the ''incipient'' Ramsauer effect. Thermalization time at gas temperature ~300 K increases, according to the present work, in the sequence He, Xe, Kr, Ne, Ar which is contributed jointly by the mass ratio and the behavior of momentum transfer cross section at low energies including the presence or absence of the Ramsauer effect. Comparison with experiments have been made where possible.

Mozumder, A.

1980-06-01

407

Fully differential single-photon double ionization of neon and argon.  

PubMed

Triply differential cross sections are calculated for one-photon double ionization of neon and argon at various photon energies and electron energy sharings by using a frozen-core treatment to represent the remaining electrons of the residual ion. Angular distributions agree well with all existing experimental data, showing that in spite of its simplicity the method can treat the double ionization of complex targets reliably. A comparison of the cross sections for helium, neon, and argon into the same final state symmetry at the same relative excess energies reveals a distinctive signature of the role of electron correlation in each target. PMID:23679717

Yip, F L; Rescigno, T N; McCurdy, C W; Martín, F

2013-04-22

408

Fully Differential Single-Photon Double Ionization of Neon and Argon  

NASA Astrophysics Data System (ADS)

Triply differential cross sections are calculated for one-photon double ionization of neon and argon at various photon energies and electron energy sharings by using a frozen-core treatment to represent the remaining electrons of the residual ion. Angular distributions agree well with all existing experimental data, showing that in spite of its simplicity the method can treat the double ionization of complex targets reliably. A comparison of the cross sections for helium, neon, and argon into the same final state symmetry at the same relative excess energies reveals a distinctive signature of the role of electron correlation in each target.

Yip, F. L.; Rescigno, T. N.; McCurdy, C. W.; Martín, F.

2013-04-01

409

Electron Excitation Coefficients in Helium, Neon, Oxygen and Methane at High E/N  

SciTech Connect

Swarm analysis is performed by comparing experimental and calculated transport coefficients. Comparisons are repeated until a satisfactory agreement is achieved after modifications of the cross sections. We have made an analysis of our excitation coefficient data for neon and methane by using detailed Monte Carlo simulation scheme. In this work we also present experimental electron excitation coefficients for other gases: helium, neon and oxygen. We used a drift tube technique to measure the absolute emission intensities in low current self sustained Townsend type discharges.

Nikitovic, Zeljka D. [Institute of Physics, P.O.B. 68, 11080 Belgrade (Serbia and Montenegro)

2006-12-01

410

Thermodynamics of a closed-cycle gas flow system for cooling a HTc DC-squid magnetometer  

Microsoft Academic Search

A multichannel high-Tc dc-SQUID based heart-magnetometer is currently under development in our laboratory. The system is cooled by a cooler that, due to its magnetic interference, has to be separated from the SQUID unit. In the present prototype system a closed-cycle gas flow was chosen as the interface between the SQUID unit and the cooler (a Leybold Heraeus RG 210).

P. J. van den Bosch; H. J. M. Ter Brake; G. C. van den Eijkel; J. P. Boelens; H. J. Holland; J. F. C. Verberne; H. Rogalla

1994-01-01

411

Thermodynamics of a closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer  

Microsoft Academic Search

A multichannel high-Tc dc-SQUID based heart-magnetometer is currently under development in our laboratory. The system is cooled by a cooler that, due to its magnetic interference, has to be separated from the SQUID unit. In the present prototype system a closed-cycle gas flow was chosen as the interface between the SQUID unit and the cooler (a Leybold Heraeus RG 210).

Bosch van den P. J; Brake ter H. J. M; Eijkel van den G. C; J. P. Boelens; H. J. Holland; J. F. C. Verberne; H. Rogalla

1994-01-01

412

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

DOEpatents

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.

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

1981-05-22

413

Antioxidative properties of aqueous and aroma extracts of squid miso prepared with Aspergillus oryzae-inoculated koji  

Microsoft Academic Search

To evaluate the antioxidative properties of a newly developed fermented paste (squid miso) prepared from squid mantle flesh with Aspergillus oryzae-inoculated koji, we used in vitro models, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, nitric oxide (NO) and carbon-centered radical-scavenging activity (RSA), reducing power ability (RPA), and linoleic acid oxidation. The antioxidant activity of volatile compounds, which were extracted from squid miso by

Anupam Giri; Kazufumi Osako; Akira Okamoto; Emiko Okazaki; Toshiaki Ohshima

2011-01-01

414

Low-frequency noise reduction in SQUID measurements using laser switching. Final report, 15 Jan 90-15 Jan 92  

SciTech Connect

The purpose of this study is to reduce SQUID noise in measurements which are intrinsically low frequency or dc. Such low frequency measurements fall below the 1/f knee of the noise energy spectrum and the SQUID performance is degraded substantially below the often quoted white noise levels. They intend to improve the low frequency noise using input circuit modulation at a frequency above the 1/f knee, up-converting the signal in frequency. In their scheme the noise should approach the SQUID white noise floor and the slew rates should approach the original SQUID system slew rate.

Cabrera, B.

1992-06-01

415

A Comparison of Theory and Experiment for PhotoIonization Cross-Sections. I. Neon and the Elements from Boron to Neon  

Microsoft Academic Search

The quantal theory of the continuous photo-electric absorption of radiation is briefly summarized, particular attention being given to the alternative formulae available and to the accuracy to be expected in practical calculations. Detailed calculations are described for the photo-ionization cross-section of neon, a system for which it is understood that experimental data should be available in the near future. The

M. J. Seaton

1951-01-01

416

Evidence of weak plasma series resonance heating in the H-mode of neon and neon/argon inductively coupled plasmas  

NASA Astrophysics Data System (ADS)

The shape of the electron energy distribution function (EEDF) in low-temperature plasmas governs the relative rates of electron-impact processes that determine key discharge properties. Comparison of EEDFs measured with probes and optical emission [1] in argon and neon inductively coupled plasmas (ICP) has revealed a surplus of high-energy electrons in neon-containing plasmas. The abundance of these extra high energy electrons is correlated with the sheath thickness near the rf antenna and can be reduced by either adding a Faraday shield or increasing the plasma density. These trends suggest an association of the surplus high-energy electrons with stochastic heating of electrons in capacitively-coupled electric fields in the sheath adjacent to the antenna. Conventional stochastic heating, however, is found to be insufficient to account for the EEDF observations, and a comparison of modeled and experimental values of the 13.56 MHz time modulation of select neon emission lines strongly suggests plasma series resonance (PSR) heating adjacent to the ICP antenna as the source of the extra high-energy electrons. [4pt] [1] Plasma Sources Sci. Technol. 20, (2011) 055006.

Wendt, A. E.; Boffard, John B.; Jung, R. O.; Lin, Chun C.; Aneskavich, L. E.

2012-10-01

417

The flying radiation case  

SciTech Connect

The Los Alamos foil implosion program has the goal of producing an intense, high-energy density x-ray source by converting the energy of a magnetically imploded plasma into radiation and material energy. One of the methods for converting the plasma energy into thermal energy and radiation and utilizing it for experiments is called the flying radiation case (FRC). In this paper the authors shall model the FRC and provide a physical description of the processes involved. An analytic model of a planar FRC in the hydrodynamic approximation is used to describe the assembly and shock heating of a central cushion by a conducting liner driver. The results are also used to benchmark a hydrodynamics code for modeling an FRC. They then use a radiation-hydrodynamics computational model to explore the effects of radiation production and transport when a gold plasma assembles on a CH cushion. Results are presented for the structure and evolution of the radiation hohlraum.

Brownell, J.H.; Bowers, R.L. [Los Alamos National Lab., NM (United States). Applied Theoretical and Computational Physics Div.

1997-04-01

418

Virtual FlyLab  

NSDL National Science Digital Library

This site is maintained by Robert Deshamais and Gary Novak of California State University at Los Angeles. Users can play the role of a research geneticist while learning the principles of genetic inheritance. Users design matings between male and female fruit flies carrying one or more genetic mutations and then click the "mate" button. The program applies known Mendelian rules to produce offspring and then asks users to deduce the rules based on the "experimental" results. The program can demonstrate such genetic mechanisms as: Mendelian ratios for dominant/recessive traits, modifications of Mendelian ratios due to sex-linkage, monozygous lethals, or epistasis. Virtual Flylab seeks "to provide students with an experience in scientific reasoning and so does not provide information on the nature of the mutations; students must discover these for themselves". The resources at this site can serve as a supplement to a genetics lecture or lab or as a review of basic genetics.

1996-01-01

419

Optical parameters of the tunable Bragg reflectors in squid.  

PubMed

Cephalopods (e.g. octopus, squid and cuttlefish) dynamically tune the colour and brightness of their skin for camouflage and communication using specialized skin cells called iridocytes. We use high-resolution microspectrophotometry to investigate individual tunable Bragg structures (consisting of alternating reflectin protein-containing, high-refractive index lamellae and low-refractive index inter-lamellar spaces) in live and chemically fixed iridocytes of the California market squid, Doryteuthis opalescens. This subcellular, single-stack microspectrophotometry allows for spectral normalization, permitting use of a transfer-matrix model of Bragg reflectance to calculate all the parameters of the Bragg stack-the refractive indices, dimensions and numbers of the lamellae and inter-lamellar spaces. Results of the fitting analyses show that eight or nine pairs of low- and high-index layers typically contribute to the observed reflectivity in live cells, whereas six or seven pairs of low- and high-index layers typically contribute to the reflectivity in chemically fixed cells. The reflectin-containing, high-index lamellae of live cells have a refractive index proportional to the peak reflectivity, with an average of 1.405 ± 0.012 and a maximum around 1.44, while the reflectin-containing lamellae in fixed tissue have a refractive index of 1.413 ± 0.015 suggesting a slight increase of refractive index in the process of fixation. As expected, incremental changes in refractive index contribute to the greatest incremental changes in reflectivity for those Bragg stacks with the most layers. The excursions in dimensions required to tune the measured reflected wavelength from 675 (red) to 425 nm (blue) are a decrease from ca 150 to 80 nm for the high-index lamellae and from ca 120 to 50 nm for the low-index inter-lamellar spaces. Fixation-induced dimensional changes also are quantified, leading us to suggest that further microspectrophotometric analyses of this iridocyte system can be used as a model system to quantify the effects of various methods of tissue fixation. The microspectrophotometry technique described can be expected to provide deeper insights into the molecular and physical mechanisms governing other biophotonically active cells and structures. PMID:23740489

Ghoshal, Amitabh; Demartini, Daniel G; Eck, Elizabeth; Morse, Daniel E

2013-06-05

420

Fly-by-Wire Flight Control Systems.  

National Technical Information Service (NTIS)

The purpose of this paper is to provide the reader with an introduction to fly-by-wire and an outline of state-of-the-art fly-by-wire techniques. An outline of the philosophy of fly-by-wire flight control systems is given, the evolution of fly-by-wire is ...

J. P. Sutherland

1967-01-01

421

Dewatered sewage biosolids provide a productive larval habitat for stable flies and house flies (Diptera: Muscidae).  

PubMed

Species diversity and seasonal abundance of muscoid flies (Diptera: Muscidae) developing in biosolid cake (dewatered biosolids) stored at a wastewater treatment facility in northeastern Kansas were evaluated. Emergence traps were deployed 19 May through 20 October 2009 (22 wk) and 27 May through 18 November 2010 (25 wk). In total, 11,349 muscoid flies were collected emerging from the biosolid cake. Stable flies (Stomoxys calcitrans (L.)) and house flies (Musca domestica (L.)), represented 80 and 18% of the muscoid flies, respectively. An estimated 550 stable flies and 220 house flies per square-meter of surface area developed in the biosolid cake annually producing 450,000 stable flies and 175,000 house flies. Stable fly emergence was seasonally bimodal with a primary peak in mid-July and a secondary peak in late August. House fly emergence peaked with the first stable fly emergence peak and then declined gradually for the remainder of the year. House flies tended to emerge from the biosolid cake sooner after its deposition than did stable flies. In addition, house fly emergence was concentrated around midsummer whereas stable fly emergence began earlier in the spring and continued later into the fall. Biosolid age and temperature were the most important parameters affecting emergence for house flies and stable flies, whereas precipitation was not important for either species. This study highlights the importance of biosolid cake as a larval developmental habitat for stable flies and house flies. PMID:22493845

Doud, C W; Taylor, D B; Zurek, L

2012-03-01

422

Magnetic-field-free measurements of the total cross sections for positron scattering from neon  

NASA Astrophysics Data System (ADS)

Magnetic-field-free measurements of the absolute total cross sections (TCS) for positron-neon scattering have been performed. In the energy range of 9-15 eV, the present results are larger than those of the other groups except for the Toronto group.

Nagumo, K.; Nitta, Y.; Hoshino, M.; Tanaka, H.; Nagashima, Y.

2012-03-01

423

Photoelectron angular correlation pattern in sequential two-photon double ionization of neon  

NASA Astrophysics Data System (ADS)

We apply an angular momentum coupling formalism to describe the angular correlation pattern in sequential two-photon double ionization of neon. Comparison with previous work (Fritzsche et al 2008 J. Phys. B: At. Mol. Opt. Phys. 41 165601) reveals some important differences which are discussed in terms of various ionization mechanisms and their theoretical implementations in two alternative approaches.

Kheifets, A. S.

2009-07-01

424

Experimental verification of dynamics modulation in a periodically-driven neon glow discharge plasma  

NASA Astrophysics Data System (ADS)

Two ionization wave modes in a driven neon glow discharge alternate as the dominant mode as their response to the driving force alternates between spatiotemporal and temporal periodic pulling. This phenomenon, termed dynamics modulation, was first noted by Koepke, Weltmann, and Selcher [1], who saw two limited but representative cases and proposed a mechanism [2] by which it occurs. Dynamics modulation is reproduced experimentally in a neon glow discharge plasma. The system is periodically driven near a non-dominant mode using a narrow-band ring dye laser tuned to a wavelength near the metastable neon transition at 588.35 nm. A spatially-fixed photodiode with a narrow band filter that selectively passes the primary neon spectral line at 640 nm is used to acquire the time series of luminosity oscillations. These experimental data are used to verify the proposed mechanism and explore the resulting implications for spontaneous unidirectional mode transitions that occur with a change in discharge current.[4pt] [1] M. E. Koepke, K.-D. Weltmann, and C. A. Selcher, Bull. Am. Phys. Soc. 40, 1716 (1995).[0pt] [2] K. -D. Weltmann, M. E. Koepke, and C. A. Selcher, Phys. Rev. E 62, 2773, (2000).

Miller, P. M.; Koepke, M. E.; Gunell, H.

2010-11-01

425

Cross-Relaxation Effects in the Saturation of the 6328-Å Neon-Laser Line  

Microsoft Academic Search

We report experiments which show that saturation of the inhomogeneously broadened 6328-Å neon-laser line is strongly affected by cross relaxation which tends to redistribute the excited atoms over the Maxwellian velocity distribution and thus leads to partially homogeneous line saturation. Our results for Ne20 discharges agree well with theoretical calculations based on a \\

P. W. Smith; R. Hänsch

1971-01-01

426

Helium, neon, and argon systematics of the European subcontinental mantle: Implications for its geochemical evolution  

Microsoft Academic Search

In this study we present a comprehensive noble gas study of mantle xenoliths from various European Cenozoic volcanic provinces. The main body of samples is from the Massif Central, France, and the Eifel, Germany. Smaller subsets of samples are from Spitsbergen and the Graz Basin, Austria. In all the helium, neon, and argon isotopic abundances of a total of forty-five

T. J. Dunaim; H. Baur

1995-01-01

427

Neural Dynamics of Form Perception: Boundary Completion, Illusory Figures, and Neon Color Spreading  

Microsoft Academic Search

A real-time visual processing theory is used to analyze real and illusory contour formation, contour and brightness interactions, neon color spreading, complementary color induction, and filling-in of discounted illuminants and scotomas. The theory also physically interprets and generalizes Land's retinex theory. These phenomena are traced to adaptive processes that overcome limitations of visual uptake to synthesize informative visual representations of

Stephen Grossberg; Ennio Mingolla

1985-01-01

428

Studium der Stationären und Laufenden Schichtung in der Entladung in Neon Mit Hilfe eines Lokalen Hochfrequenzfeldes  

Microsoft Academic Search

Zusammenfassung Es wurde ein Verfahren zur Erregung von stationären Schichten, der Schichtungswelle und der laufenden Schichten in der Gleichstromentladung ausgearbeitet, das auf der Einwirkung eines Hochfrequenzfeldes auf einen kurzen Abschnitt der positiven Säule beruht. Dieses Verfahren wurde zum Studium aller drei angeführten Schichtungsarten in Neon benützt, insbesondere jedoch zum Studium des Zusammenhanges zwischen den laufenden und den stationären Schichten.

M. Šícha; V. Veselý; J. Studnicka; J. Prostejovský; M. Novák

1962-01-01

429

Mechanisms controlling the global oceanic distribution of the inert gases argon, nitrogen and neon  

Microsoft Academic Search

Dissolved inert gas measurements in the ocean yield important information about processes that occur during water mass formation. We present argon, nitrogen, and neon data from the subtropical and subpolar North Pacific and the subtropical North Atlantic. All three gases were supersaturated at the surface. In the deep ocean, Ar and N2 were undersaturated while Ne re- mained supersaturated. All

Roberta C. Hamme; Steven R. Emerson

2002-01-01

430

A Magnus opus: Helium, neon, and argon isotopes in a North Sea oilfield  

Microsoft Academic Search

This study of the Magnus oilfield, located in the East Shetland Basin, northern North Sea, represents the most detailed investigation of noble gas isotope systematics in a liquid hydrocarbon reservoir yet undertaken. Samples from nine producing wells across this Middle Jurassic field were taken and the helium, neon, and argon isotopic ratios and abundances in the oil were determined. Both

C. J. Ballentine; M. L. Coleman

1996-01-01

431

A Micro-Analysis of the Helium and Neon Contents of Air  

Microsoft Academic Search

The first part of the paper deals with the quantitative separation of gases by fractional adsorption, the theoretical conditions of which had to be investigated before a really accurate helium analysis could be undertaken. The second part describes the micro-method and apparatus used for the determination of the helium and neon contents of atmospheric air, and discusses questions affecting the

E. Gluckauf

1946-01-01

432

Vermicompost Effects on the Growth and Flowering of Petunia hybrida 'Dream Neon Rose  

Microsoft Academic Search

The effects of vermicompost of an animal manure origin on the growth and flowering of Petunia hybrida 'Dream Neon Rose' grown under glasshouse conditions were determined. Petunia seeds were germinated, transplanted into media and grown-on for 150 days. The traditional base medium (control) was a mix ture of 70% farm soil and 30% sand (v\\/v). Treatments were either vermicompost incorporated

E. Chamani; D. C. Joyce; A. Reihanytabar

2008-01-01

433

Helium-neon laser radiation effect on fish embryos and larvae  

Microsoft Academic Search

Helium-neon laser irradiation (HNLI) is an effective biostimulating agent but its influence on embryonal processes is almost unknown. We have studied fish embryos and larvae development, viability, and growth after HNLI of fish eggs at different stages. With this aim carp, grass carp, sturgeon, and stellared sturgeon eggs were incubated in Petri plates or in fish-breeding apparatuses and were irradiated

Anatoly B. Uzdensky

1994-01-01

434

Specific heats of dilute neon inside a long single-walled carbon nanotube  

Microsoft Academic Search

An elegant formula for coordinates of carbon atoms in a unit cell of a single-walled nanotube (SWNT) is presented and the potential of neon (Ne) inside an infinitely long SWNT is analytically derived under the condition of the Lennard-Jones potential between Ne and carbon atoms. Specific heats of dilute Ne inside a long (20, 20) SWNT are calculated at different

Z. C. Tu; Z. C. Ou-Yang

2003-01-01

435

Adsorption measurements of argon, neon, krypton, nitrogen, and methane on activated carbon up to 650 MPa  

Microsoft Academic Search

The physisorption of argon, krypton, neon, nitrogen, and methane on GAC activated carbon has been measured in the above critical region by a dielectric method. The measurements were done at room temperature and at pressures up to 650 MPa corresponding to reduced densities of up to 3.25. With the exception of nitrogen, all the measured excess adsorption isotherms show a

P. Malbrunot; D. Vidal; J. Vermesse; R. Chahine; T. K. Bose

1992-01-01

436

Capture Cross Sections of the Neon Isotopes and the S-Process Neutron Balance.  

National Technical Information Service (NTIS)

The neutron capture cross sections of the three stable neon isotopes have been measured by the time-of-flight method in the energy range from 5 to 200 keV, using hydrogen free fast liquid scintillator detectors and the Maier-Leibnitz pulse height weightin...

J. Almeida

1982-01-01

437

Neon Lights up a Controversy: The Solar Ne/O Abundance  

NASA Astrophysics Data System (ADS)

The standard solar model was so reliable that it could predict the existence of the massive neutrino. Helioseismology measurements were so precise that they could determine the depth of the convection zone. This agreement between theory and observation was the envy of all astrophysics-until recently, when sophisticated three-dimensional hydrodynamic calculations of the solar atmosphere reduced the metal content by a factor of almost 2. Antia & Basu suggested that a higher value of the solar neon abundance, ANe/AO=0.52, would resolve this controversy. Drake & Testa presented evidence in favor of this idea from a sample of 21 Chandra stars with enhanced values of the neon abundance, ANe/AO=0.41. In this Letter, we have analyzed solar active region spectra from the archive of the Flat Crystal Spectrometer on the Solar Maximum Mission, a NASA mission from the 1980s, as well as full-Sun spectra from the pioneering days of X-ray astronomy in the 1960s. These data are consistent with the standard neon-to-oxygen abundance value, ANe/AO=0.15 (Grevesse & Sauval). We conclude, therefore, that the enhanced-neon hypothesis will not resolve the current controversy.

Schmelz, J. T.; Nasraoui, K.; Roames, J. K.; Lippner, L. A.; Garst, J. W.

2005-12-01

438

Connected Triple Excitations in Coupled-Cluster Calculations of Hyperpolarizabilities: Neon.  

National Technical Information Service (NTIS)

We have calculated the second hyperpolarizability gamma of neon using the CCSD(T) method. The accuracy of the CCSD(T) approach has been established by explicit comparison with the single, double and triple excitation coupled-cluster (CCSDT) method using e...

J. E. Rice G. E. Scuseria T. J. Lee P. R. Taylor J. Almloef

1992-01-01

439

Statistical analysis of electrical breakdown time delay distributions in neon tube at 13.3 mbar  

Microsoft Academic Search

Results of the statistical analysis of the electrical breakdown time delay for a neon-filled tube at 13.3 mbar are presented in this paper. Experimental distributions of the breakdown time delay were established on the basis of 1000 successive and independent measurements, deviating from usual exponential distribution. Breakdown time delay distributions are numerically generated from the composition of two parameters, which

Cedomir A. Maluckov; Jugoslav P. Karamarkovic; M. K. Radovic

2003-01-01

440

New Models And Distributions Of The Electrical Breakdown Time Delay In Neon  

Microsoft Academic Search

The measurements of the electrical breakdown time delay dt in DC neon glow discharge for a wide range of working voltages and at different preionization levels are presented. The statistical breakdown time delay ts and the discharge formative time ft are experimentally separated and theoretical models of their dependencies on the overvoltage and number densities of residual charges during relaxation

S. N. Stamenkovic

2010-01-01

441

Fluctuations and correlations of the formative and statistical time delay in neon  

Microsoft Academic Search

The fluctuations and correlations of the formative tf and statistical time delay ts in neon are studied by electrical breakdown time delay measurements. The measurements were carried out at different preionization levels (afterglow periods) and the Gaussian distributions for the formative time were obtained to about 20 ms in afterglow. The formative time increases linearly with the afterglow period consistently

V Lj Markovi?; S R Goci?; S N Stamenkovi?

2009-01-01

442

Metastable and charged particle decay in neon afterglow studied by the breakdown time delay measurements  

NASA Astrophysics Data System (ADS)

Memory effect-the long time variation of the electrical breakdown time delay on the relaxation time td(?) in neon-was explained by the Ne(3P2) (1s5) metastable state remaining from the preceding glow [Dj. A. Bošan, M. K. Radovi?, and Dj. M. Krmpoti?, J. Phys. D 19, 2343 (1986)]. However, the authors neglected the quenching processes that reduce the effective lifetime of metastable states several orders of magnitude below that of the memory effect observations. In this paper the time delay measurements were carried out in neon at the pressure of 6.6 mbar in a gas tube with gold-plated copper cathode, and the approximate and exact numerical models are developed in order to study the metastable and charged particle decay in afterglow. It was found that the metastable hypothesis completely failed to explain the afterglow kinetics, which is governed by the decay of molecular neon ions and molecular nitrogen ions produced in Ne2+ collisions with nitrogen impurities; i.e., Ne2++N2-->N2++2Ne. Charged particle decay is followed up to hundreds of milliseconds in afterglow, from ambipolar to the free diffusion limit. After that, the late afterglow kinetics in neon can be explained by the nitrogen atoms recombining on the cathode surface and providing secondary electrons that determine the breakdown time delay down to the cosmic rays and natural radioactivity level.

Markovi?, V. Lj.; Goci?, S. R.; Stamenkovi?, S. N.; Petrovi?, Z. Lj.

2007-10-01

443

[Effect of helium-neon laser radiation on the radiosensitivity of Escherichia coli K-12 cells].  

PubMed

A study was made of the combined effect of laser radiation (helium-neon laser, lambda = 633 nm) and X-rays on bacteria of different genotypes. The sensitivity of cells to X-rays was decreased by pre- and post-irradiation with laser. In the latter case, the radio-modifying effect of laser was more pronounced. PMID:3898212

Voskanian, K Sh; Simonian, N V; Avakian, Ts M; Arutiunian, A G

444

Effect of illumination of a neon discharge on the electron energy distribution  

Microsoft Academic Search

It is found experimentally that the illumination of a neon discharge results in reductions of both the electron density and the metastable population and thus there is evidence for cumulative ionization. In addition there is a downward trasfer of electrons in velocity space.

M. G. Drouet; J. P. Novak

1971-01-01

445

The influence of neutral gas temperature on the parameters of ionization waves in neon  

Microsoft Academic Search

In the present paper, the influence of cooling down the neutral gas to a temperature of 77°K on the parameters of ionization waves excited in the positive column of a d. c. glow discharge in neon is studied. After the cooling, the group velocity, phase velocity, frequency and relaxation time of the waves of varietyp decreased and they increased in

K. Masek; V. Pe?ina

1968-01-01

446

Investigation of an He-Ne laser at various 3s-2p transitions of neon  

Microsoft Academic Search

Lasing was achieved on a series of 3s2-2p transitions of neon in resonators without selective elements. Good agreement was found between calculated and measured gain values. Attention is given to the parameters of mass-produced devices that can operate at the above-mentioned transitions.

Ia. M. Bondarchuk; V. G. Leont'ev; V. E. Privalov; G. I. Solov'eva

1988-01-01

447

PRODUCTION OF A SLOW, MONOENERGETIC METASTABLE NEON BEAM FOR ATOM DIFFRACTION STUDIES  

Microsoft Academic Search

We present characterization results from a series of atom-optical elements designed to produce a slow, monochromatic metastable neon atomic beam source. These elements include a two dimensional optical collimator, a Zeeman slower and a hexapole magnetic bender. The beam will be diffracted from various gratings for studies of the van der Waals forces governing atom-surface interactions.

A. J. Palmer; J. Beardmore; T. Hourigan; M. Baker; R. T. Sang

448

Neon and Sulfur Abundances of Planetary Nebulae in the Magellanic Clouds  

Microsoft Academic Search

The chemical abundances of neon and sulfur for 25 planetary nebulae (PNe) in the Magellanic Clouds are presented. These abundances have been derived using mainly infrared data from the Spitzer Space Telescope. The implications for the chemical evolution of these elements are discussed. A comparison with similarly obtained abundances of Galactic PNe and H II regions and Magellanic Cloud H

J. Bernard-Salas; S. R. Pottasch; S. Gutenkunst; P. W. Morris; J. R. Houck

2008-01-01

449

Molecular mechanics and molecular dynamics analysis of Drexler-Merkle gears and neon pump  

Microsoft Academic Search

Over the past two years at the Materials and Process Simulation Center, we have been developing simulation approaches for studying the molecular nanomachine designs pioneered by Drexler and Merkle. These nanomachine designs, such as planetary gears and neon pump, are described with atomistic details and involve up to 10 000 atoms. With the Dreiding and universal force fields, we have

T Caginyx; A Jaramillo-Boterozk; G. Gao; W. A. Goddard III

1998-01-01

450

Acoustic Studies of Liquid-Vapor Critical Behavior of Neon and Helium in Aerogels  

Microsoft Academic Search

We have used an acoustic resonator to study the liquid-vapor coexistence curve and critical region of simple fluids (neon and helium) confined in high porosity silica aerogels. A diverging isothermal compressibility at a critical point appears as a sharp minimum in the sound velocity. The low frequencies of the resonator (a few kHz) allow a more direct probe of the

Tobias Herman; John Beamish

2002-01-01

451

Second sound waves in orthodeuterium, parahydrogen quantum crystals and neon crystals  

Microsoft Academic Search

The possibility of second sound wave propagation in isotopic pure ideal single crystals of orthodeuterium, parahydrogen, and neon is studied. The same collision frequencies as those used in Callaway's model to describe experimental data on thermal conductivity are used to find the region of existence of second-sound waves, which lies in the region of the maximum value of the thermal

V. D. Khodusov; A. A. Blinkina

2009-01-01

452

Aquatic Biogeochemical Prototype Activities at the National Ecological Observatory Network (NEON)  

NASA Astrophysics Data System (ADS)

NEON is currently prototyping select data collections in order to develop robust protocols and procedures to be used across a gradient of stream systems, evaluating morphological mapping tools, and designing lightweight equipment and secure, stable, non-intrusive sensor installations. Here we present the status of the Aquatic prototype efforts that are occurring at the D15 Candidate Core Aquatic site: Red Butte Creek, Utah. Prototype activities include discharge and reaeration measurements, development of a stream reaeration rating curve, and water chemistry sampling. We are measuring reaeration, a measure of gas exchange across the air-water interface, using a continuous injection of SF6, an inert gas. In addition, Cl-, a conservative tracer, is added to the stream to account for dilution by groundwater inputs. As part of the NEON Prototype effort, we re-designed a lightweight, easy-to- use pump system for the addition of this conservative tracer during reaeration measurements. This pump, which costs a fraction of commercially available pumps, has performed well during field-testing and meets NEON’s needs and requirements for the injection of the conservative tracer. The NEON prototype efforts will help ensure that the data collected across the Observatory, including the 36 aquatic sites across 19 ecoclimatic domains, will enable researchers to investigate and model ecosystems response to climate change and landuse change at multiple spatial and temporal scales. The Observatory will collect data from both in-situ sensors and field data collections to produce measurements using consistent and standardized procedures and protocols across the United States. During Observatory Operations, these data will be available to the public on the web in near-real time.

Goodman, K. J.; Powell, H.; Cilke, T.; Price, A.

2010-12-01

453

RECTIFICATION AND INDUCTANCE IN THE SQUID GIANT AXON  

PubMed Central

Previous measurements have shown that the electrical properties of the squid axon membrane are approximately equivalent to those of a circuit containing a capacity shunted by an inductance and a rectifier in series. Selective ion permeability of a membrane separating two electrolytes may be expected to give rise to the rectification. A quasi-crystalline piezoelectric structure of the membrane is a plausible explanation of the inductance. Some approximate calculations of behavior of an axon with these membrane characteristics have been made. Fair agreement is obtained with the observed constant current subthreshold potential and impedance during the foot of the action potential. In a simple case a formal analogy is found between the calculated membrane potential and the excitability defined by the two factor formulations of excitation. Several excitation phenomena may then be explained semi-quantitatively by further assuming the excitability proportional to the membrane potential. Some previous measurements and subthreshold potential and excitability observations are not consistent with the circuit considered and indicate that this circuit is only approximately equivalent to the membrane.

Cole, Kenneth S.

1941-01-01

454

Optimization of the R-SQUID noise thermometer  

SciTech Connect

The Josephson junction can be used to convert voltage into frequency and thus it can be used to convert voltage fluctuations generated by Johnson noise in a resistor into frequency fluctuations. As a consequence, the temperature of the resistor can be defined by measuring the variance of the frequency fluctuations. Unfortunately, the absolute determination of temperature by this approach is disturbed by several undesirable effects: a rolloff introduced by the bandwidth of the postdetection filter, additional noise caused by rf amplifiers, and a mixed noise effect caused by the nonlinearity of the Josephson junction together with rf noise in the tank circuit. Furthermore, the variance is a statistical quantity and therefore the limited number of frequency counts produces inaccuracy in a temperature measurement. In this work the total inaccuracy of the noise thermometer is analyzed and the optimal choice of the parameters is derived. A practical way to find the optimal conditions for the Josephson junction noise thermometer is discussed. The inspection shows that under the optimal conditions the total error is dependent only on the temperature under determination, the equivalent noise temperature of the preamplifier, the bias frequency of the SQUID, and the total time used for the measurement.

Seppae, H.

1986-02-01

455

Metabolic efficiency with fast spiking in the squid axon  

PubMed Central

Fundamentally, action potentials in the squid axon are consequence of the entrance of sodium ions during the depolarization of the rising phase of the spike mediated by the outflow of potassium ions during the hyperpolarization of the falling phase. Perfect metabolic efficiency with a minimum charge needed for the change in voltage during the action potential would confine sodium entry to the rising phase and potassium efflux to the falling phase. However, because sodium channels remain open to a significant extent during the falling phase, a certain overlap of inward and outward currents is observed. In this work we investigate the impact of ion overlap on the number of the adenosine triphosphate (ATP) molecules and energy cost required per action potential as a function of the temperature in a Hodgkin–Huxley model. Based on a recent approach to computing the energy cost of neuronal action potential generation not based on ion counting, we show that increased firing frequencies induced by higher temperatures imply more efficient use of sodium entry, and then a decrease in the metabolic energy cost required to restore the concentration gradients after an action potential. Also, we determine values of sodium conductance at which the hydrolysis efficiency presents a clear minimum.

Moujahid, Abdelmalik; d'Anjou, Alicia

2012-01-01

456

Voltage-independent gating transitions in squid axon potassium channels.  

PubMed Central

We have investigated the actions of internal and external Zn2+ on squid axon K channel ionic and gating currents. As has been noted previously, application of Zn2+ to either membrane surface substantially slowed the activation of these channels with little or no change in deactivation. Internal Zn2+ (near 200-300 nM) slowed channel activation by up to sixfold over the range of membrane voltages from -30 to +50 mV. External Zn2+ (10 mM) produced an approximate twofold slowing of activation from -40 to +40 mV. We found that the changes in ionic current activation kinetics were accompanied by less than a twofold slowing of channel-gating currents in a narrow range of potentials near -30 mV. There was, at most, only a few percent reduction of charge movement associated with Zn2+ application. We conclude that these ions interact with channel components involved in weakly voltage-dependent conformational changes. Although there are some differences in detail, the general similarity of the actions of both internal and external Zn2+ on channel function suggests that the modified channel-gating step involves amino acids accessible to both the internal and external membrane surface.

Spires, S; Begenisich, T

1995-01-01

457

Ionic Current Measurements in the Squid Giant Axon Membrane  

PubMed Central

The concepts, experiments, and interpretations of ionic current measurements after a step change of the squid axon membrane potential require the potential to be constant for the duration and the membrane area measured. An experimental approach to this ideal has been developed. Electrometer, operational, and control amplifiers produce the step potential between internal micropipette and external potential electrodes within 40 microseconds and a few millivolts. With an internal current electrode effective resistance of 2 ohm cm.2, the membrane potential and current may be constant within a few millivolts and 10 per cent out to near the electrode ends. The maximum membrane current patterns of the best axons are several times larger but of the type described by Cole and analyzed by Hodgkin and Huxley when the change of potential is adequately controlled. The occasional obvious distortions are attributed to the marginal adequacy of potential control to be expected from the characteristics of the current electrodes and the axon. Improvements are expected only to increase stability and accuracy. No reason has been found either to question the qualitative characteristics of the early measurements or to so discredit the analyses made of them.

Cole, Kenneth S.; Moore, John W.

1960-01-01

458

Effect of Detergent on Electrical Properties of Squid Axon Membrane  

PubMed Central

The effects of detergents on squid giant axon action and resting potentials as well as membrane conductances in the voltage clamp have been studied. Anionic detergents (sodium lauryl sulfate, 0.1 to 1.0 mM; dimethyl benzene sulfonate, 1 to 20 mM, pH 7.6) cause a temporary increase and a later decrease of action potential height and the value of the resting potential. Cationic detergent (cetyl trimethyl ammonium chloride, 6 x 10-5M or more, pH 7.6) generally brings about immediate and irreversible decreases in the action and resting potentials. Non-ionic detergent (tween 80, 0.1 M, pH 7.6) causes a slight reversible reduction of action potential height without affecting the value of the resting potential. Both anionic and cationic detergents generally decrease the sodium and potassium conductances irreversibly. The effect of non-ionic detergent is to decrease the sodium conductance reversibly, leaving the potassium conductance almost unchanged.

Kishimoto, Uichiro; Adelman, William J.

1964-01-01

459

Squid Axon Membrane Response to White Noise Stimulation  

PubMed Central

The current from a white noise generator was applied as a stimulus to a space-clamped squid axon in double sucrose gap. The membrane current and the voltage response of the membrane were then amplified, recorded on magnetic tape, and the stimulus was cross-correlated with the response. With subthreshold stimuli, a cross-correlation function resembling that obtained from a resonant parallel circuit is obtained. As the intensity of the input noise is increased, the cross-correlation function resembles that obtained from a less damped oscillatory circuit. When the noise intensity is further increased so that an appreciable frequency of action potentials is observed, an additional component appears in the experimental cross-correlogram. The subthreshold cross-correlogram is analyzed theoretically in terms of the linearized Hodgkin-Huxley equations. The subthreshold axon approximates a parallel resonant circuit. The circuit parameters are temperature dependent, with resonant frequency varying from approximately 100 Hz at 10°C to approximately 250 Hz at 20°C. The Q10 of the resonant frequency is equal to 1.9. These values are in agreement with values found previously for subthreshold oscillations following a single action potential.

Guttman, Rita; Feldman, Lance; Lecar, Harold

1974-01-01

460

High-Tc SQUID gradiometer system for immunoassays  

NASA Astrophysics Data System (ADS)

A high-Tc dc SQUID (superconducting quantum interference device) gradiometer was developed for magnetic immunoassays where magnetic nanoparticles are used as markers to detect biological reactions. The gradiometer was fabricated on a 5 × 10 mm2 SrTiO3 bicrystal substrate and has a gradiometer resolution of 2.1 pT cm-1 Hz-1/2. A magnetic signal was detected from a sample of 1 µl of Fe3O4 nanoparticles in a 40 mg ml-1 solution kept in a microcavity fabricated on Si wafers with Si3N4 membranes using MEMS (micro-electro-mechanical-systems) technology. It was found that volumes as small as 0.3 nl in principle would be detectable with our present device. This corresponds to a total number of particles of 2.2 × 107. The estimated average dipole moment per particle is 4.8 × 10-22 A m2. We are aiming at reading out immunoassays by detecting the Brownian relaxation of magnetic nanoparticles, and we also intend to integrate MEMS technology into our system.

Öisjöen, F.; Magnelind, P.; Kalabukhov, A.; Winkler, D.

2008-03-01

461

Mean square flux noise in SQUIDs and qubits: numerical calculations  

NASA Astrophysics Data System (ADS)

The performance of SQUIDs and superconducting qubits based on magnetic flux is degraded by the presence of magnetic flux noise with a spectral density scaling approximately inversely with frequency. It is generally accepted that the noise arises from the random reversal of spins on the surface of the superconductors. We introduce a numerical method of calculating the mean square flux noise \\langle {\\Phi }_{{}}^{2}\\rangle from independently fluctuating spins on the surface of thin-film loops of arbitrary geometry. By reciprocity, \\langle {\\Phi }_{{}}^{2}\\rangle is proportional to , where B(r) is the magnetic field generated by a circulating current around the loop and r varies over the loop surface. By discretizing the loop nonuniformly, we efficiently and accurately compute the current distribution and resulting magnetic field, which may vary rapidly across the loop. We use this method to compute \\langle {\\Phi }_{{}}^{2}\\rangle in a number of scenarios in which we systematically vary physical parameters of the loop. We compare our simulations to an earlier analytic result predicting that \\langle {\\Phi }_{{}}^{2}\\rangle \\propto R/W in the limit where the loop radius R is much greater than the linewidth W. We further show that the previously neglected contribution of edge spins to \\langle {\\Phi }_{{}}^{2}\\rangle is significant—even dominant—in narrow-linewidth loops.

Anton, S. M.; Sognnaes, I. A. B.; Birenbaum, J. S.; O'Kelley, S. R.; Fourie, C. J.; Clarke, John

2013-07-01

462

Studies of Phlebotomine Sand Flies.  

National Technical Information Service (NTIS)

A biosystematic review of the bloodsucking psychodid flies of Colombia was completed. Of the 105 taxa studied, 14 represent previously underscribed forms. Each species is keyed, figured and discussed. An extensive bibliography is provided. The review, to ...

D. G. Young

1977-01-01

463

Studies of Phlebotomine Sand Flies.  

National Technical Information Service (NTIS)

A preliminary key to the phlebotomine sand flies of Kenya was prepared as an aid to identification. The need for fresh material readily apparent. Further progress was made on illustrating important features of New World species, necessary for inclusion in...

D. G. Young

1980-01-01

464

Interactive Fly: Germ Band Extension  

NSDL National Science Digital Library

In situ images from an award-winning and comprehensive site, The Interactive Fly. Entering through an expression pattern, this site thoroughly discusses each genes and shows its expression relative to other genes at this stage.

PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

2006-12-12

465

Interactive Fly: CNS Expression Images  

NSDL National Science Digital Library

In situ images from an award-winning and comprehensive site, The Interactive Fly. Entering through an expression pattern, this site thoroughly discusses each genes and shows its expression relative to other genes at this stage.

PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

2006-12-12

466

Flying and Your Child's Ears  

MedlinePLUS

... Tips for Easing Ear Pain Flying's Effects on Ears Many of us have felt that weird ear- ... equalization happen more easily. Continue Tips for Easing Ear Pain Some simple things to try during air ...

467

Managing the Fruit Fly Experiment.  

ERIC Educational Resources Information Center

|Describes a sophisticated version of the fruit fly experiment for teaching concepts about genetics to biology students. Provides students with the opportunity to work with live animals over an extended period. (JRH)|

Jeszenszky, Arleen W.

1997-01-01

468

Mobile HTS-SQUID NDE system with robot arm and active shielding using fluxgate  

NASA Astrophysics Data System (ADS)

A robot-arm-based mobile HTS-SQUID NDE system was developed for inspection of advanced structures such as hydrogen fuel cell tanks. In order to realize stable operation of HTS-SQUID exposed in Earth’s field and robot arm’s noise without flux trapping, flux jumping and unlocking during motion, a new active magnetic shielding (AMS) technique using fluxgate was introduced. The high sensitive fluxgate, which could measure magnetic field of up to several 10 ?T, was mounted near an HTS-SQUID gradiometer on the robot arm to measure the ambient noise and feed back its output to a compensation coil, which surrounded both SQUID and fluxgate to cancel the ambient noise around them. The AMS technique successfully enabled the HTS-SQUID gradiometer to be moved at 10 mm/s by the robot arm in unshielded environment without flux trapping, jumping and unlocking. Detection of hidden slots in multi-layer composite-metal structures imitating the fuel cell tank was demonstrated.

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

2008-09-01

469

Quality changes in squid (Loligo duvaucelli) tubes chilled with dry ice and water ice.  

PubMed

Squid tubes were packed with 100% (w/w of squid) dry ice (PI), 20% dry ice and 50% water ice (PII) and 50% water ice (PIII) in polyethylene bags and store in thermocole boxes at room temperature (32 ± 2°C) for 24 h. Quality changes curing storage were studied. Lowest temperature of -30.3°C was attained in PI while it was 15-16°C in PII and PIII at 1 h of storage. The gas compositions in packages initially were 21% O2, 0.4% CO2 and 78.1% N2 in PI, PII and PIII, respectively. During storage for 24 h highest level of 82.5% CO2 was noticed in PII. Fresh squid tubes had bacterial flora of Hafnia, Pseudomonas, Bacillus, Flavobacterium and Alcaligens. Hafnia constituted 74% of the flora. Alcaligenes (47%), Alteromonas (30%) and Alcaligenes (56%) were dominant in squid tubes stored in 100% dry ice, in the combination package, and in 100% water ice, respectively. Increase in total volatile base nitrogen and trimethylamine nitrogen, no definite trend in free fatty acid values in all packages while increase in pH in PI and PIII and no consistent changes in PI were noticed during storage for 24 h. The PI had lowest bacterial counts and PIII the highest. Squids stored in PI and PII were sensorily acceptable after 24 and 18 h, respectively. PMID:23572660

Jeyasekaran, G; Jeya Shakila, R; Sukumar, D; Ganesan, P; Anandaraj, R

2010-09-08

470

Development of SQUID microscope for localization and imaging of material defects (NDE)  

SciTech Connect

Dramatic progress was made in FY1997, the first full year of implementing a new technique for detecting and imaging material defects in nuclear weapon components. Design, fabrication, and initial tests of a ``SQUID Microscope`` has been completed utilizing the extraordinary sensitivity of High-Critical-Temperature (HTC) Superconducting QUantum Interference Device (SQUID) technology. SQUIDs, the most sensitive magnetic field detectors known, are used to sense magnetic anomalies caused by the perturbation of an induction field by defects in the material under examination. Time variation of the amplitude (A) and angle ({theta}) of an induction field with unique spatial distribution allows examination of material defects as a function of depth and orientation within the sample. Variation of the frequency of amplitude variation, {Omega}(A), enables depth selection in a given sample. Scanning the sample in physical, A, and {theta} space enables detection and localization of defects to high precision. A few examples of the material defects anticipated for study include cracks, stress fractures, corrosion, separation between layers, and material inclusions. Design and fabrication of a prototype SQUID Microscope has been completed during FY97. Extensive testing of the physical, thermal, precision mechanical, and vacuum performance of the SQUID microscope were performed. First preliminary tests of the integrated system have been performed and initial results were obtained in the first week of September 1997, more than 3 months ahead of schedule.

Kraus, R.H. Jr.; Espy, M.; Atencio, L.

1997-10-01

471

Neuroanatomy: decoding the fly brain.  

PubMed

Despite their relatively small brains, with only about 100,000 neurons, fruit flies show many complex behaviours. Understanding how these behaviours are generated will require a wiring diagram of the brain, and significant progress is being made towards this goal. One study has labelled 16,000 individual neurons and generated a coarse wiring diagram of the whole fly brain, identifying subnetworks that may carry out local information processing. PMID:21215929

Kohl, Johannes; Jefferis, Gregory S X E

2011-01-11

472

Seafloor mapping and landscape ecology analyses used to monitor variations in spawning site preference and benthic egg mop abundance for the California market squid ( Doryteuthis opalescens)  

Microsoft Academic Search

The California squid fishery is concentrated largely on nearshore squid spawning aggregations. Because of this practice a central concern for sustainable squid fisheries in California is to determine whether reproductive activities and subsequent egg laying occur at rates that are sufficient to support harvestable populations of this sub-annual species. Using high-resolution data collected via acoustic mapping methodology, we estimated a

Mary A. Young; Rikk G. Kvitek; Pat J. Iampietro; Corey D. Garza; Richard Maillet; Roger T. Hanlon

2011-01-01

473

Impact of visible implant elastomer tags on the growth rate of captive Caribbean reef squid Sepioteuthis sepioidea  

Microsoft Academic Search

Laboratory growth studies and field work based on statoliths provide differing growth data for cephalopods. The goal of this study was to determine if visible implant elastomer (VIE) tags impact growth or mortality rates of Caribbean reef squid, Sepioteuthis sepioidea, Blainville. Five tanks with six tagged and six untagged squid in each were tested. There was no statistical difference in

Kimberly M. Zeeh; James B. Wood

2009-01-01

474

Squid-based picovoltmeter for measuring resistance of metals at low temperatures and volt-ampere characteristics of superconductor structures  

Microsoft Academic Search

This paper describes apparatus for measuring the electrical conductivity of metals and alloys at low temperatures as well as for recording the volt-ampere characteristics of superconductor structures in which the voltmeter is a radio-frequency squid with negative voltage feedback from the output of the electronic unit of the squid to the input measuring circuit. The principal components of the apparatus

Krasnopolin

1986-01-01

475

Experimental study on the effect of diet on fatty acid and stable isotope profiles of the squid Lolliguncula brevis  

Microsoft Academic Search

Fatty acid and stable isotope analyses have previously been used to investigate foraging patterns of fish, birds, marine mammals and most recently cephalopod species. To evaluate the application of these methods for dietary studies in squid, it is important to understand the degree to which fatty acid and stable isotope signatures of prey species are reflected in the squids' tissue.

Gabriele Stowasser; Graham J. Pierce; Colin F. Moffat; Martin A. Collins; John W. Forsythe

2006-01-01

476

Non-Destructive Testing (NDT) of Metal Cracks Using a High TC RF-Squid and Eddy Current Method.  

National Technical Information Service (NTIS)

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 chea...

1995-01-01

477

Factors influencing the embryonic development and hatchling size of the oceanic squid Illex coindetii following in vitro fertilization  

Microsoft Academic Search

Egg masses of oceanic squid accidently collected in the wild have been observed only from a few spawning events in aquaria, and as a consequence, the study of their embryos and hatchlings is very limited. Here, we used in vitro fertilization techniques to understand the abiotic factors that influenced egg development and hatchling performance of the ommastrephid squid Illex coindetii

Roger Villanueva; Daniel Quintana; Giuliano Petroni; Anna Bozzano

2011-01-01

478

Tempus Fugit: Time Flies  

NSDL National Science Digital Library

This online exhibit from a prominent American museum explores the character of time -- its impact on our daily lives and its ability to shape and reform human consciousness. Tempus Fugit: Time Flies is a superb exhibit from the Nelson Atkins Museum of Art that uses items from the museum to exemplify different understandings of time. The exhibit features sections on 20th Century Time, World Times, and Conservation Time. Twentieth-century time considers the changing nature of time in the technological age by examining the innovations in graphic and plastic arts inspired by an altered sense of time. The exhibit includes works by Muybridge, Edward Hopper, Salvador Dali, Kandinsky, Rothko, Roy Lichtenstein, and others. The second section, World Times, focuses on the different conceptions of time embodied in art from primitive times to the present and ranges from ancient Native American to Medieval Europe to ancestral Africa to the deeply cosmological perceptions of time in ancient Indian civilizations. Conservation Time takes visitors behind the scenes to see how conservation science can uncover the history of a work's composition and the changes wrought upon it over the course of its lifetime. The Website also offers ideas for teaching using the exhibits. In sum, this is an elegantly constructed and intelligent Website. To be sure, users will want to set aside some time for it as the graphics enforce their own meditative pace upon the viewer.

479

SQUID systems for non-destructive testing by AC field mapping  

NASA Astrophysics Data System (ADS)

The authors describe a low-temperature liquid-helium SQUID system with high spatial resolution and a wider bandwidth than usual for an all-metal cryostat and which also provides access for a mechanism to balance the pick-up coils. They discuss the effects of these properties on ac field measurement and present experimental results from small slits which mimic growing fatigue cracks. Related work on high-temperature superconducting devices indicates that they will offer important advantages over low-temperature SQUIDs, particularly in terms of cryogenic design which has been so restrictive in low-temperature systems. The authors suggest that even relatively poor high-temperature-superconductor SQUID performance will be acceptable if these advantages can be exploited.

Cochran, A.; Morgan, L. N. C.; Bowman, R. M.; Kirk, K. J.; Donaldson, G. B.

1993-03-01

480

Detecting fatigue damage in 2.25Cr-1Mo steel with scanning SQUID gradiometry  

NASA Astrophysics Data System (ADS)

In order to develop a new method for detecting fatigue damage nondestructively in 2.25Cr-1Mo steel, which is used in high temperature steam piping of fossil power plants and petroleum chemical facilities, fractured and interrupted samples in low-cycle fatigue (LCF) tests were investigated using scanning superconducting quantum interference device (SQUID) gradiometer. High temperature LCF experiments on 2.25Cr-1Mo steel were conducted to obtain various fatigue damage ratio, Df. Simultaneously, we also examined the fatigued samples by optical microscopy, electron back scatter diffraction pattern, magnetic force microscopy and hardness measurements to analyze the damage level. Except for a couple of samples, SQUID integrated intensity decreased with increasing Df, suggesting the potential of SQUID to evaluate fatigue damage in 2.25Cr-1Mo steel.

Isawa, K.; Hasegawa, S.; Miyaguchi, K.

2009-10-01

481

Genetic screening for prey in the gut contents from a giant squid (Architeuthis sp.).  

PubMed

Giant squids (Architeuthis sp.) remain mysterious; they have evaded observation and are rarely taken from their deep sea habitat. Information on the diet of Architeuthis is scarce due to the limited number of specimens with morphologically recognizable remains in their digestive tracts. We explored the use of polymerase chain reaction (PCR)-based methods for detection of DNA in the prey remains and amorphous slurry from an Architeuthis gut sample. The DNA region amplified varied in size, allowing separation of fish and squid components. Sequence comparisons identified fish prey as Macruronus novaezelandiae. Isolation of Architeuthis DNA from an ingested tentacle and the presence of chitin fragments indicate cannibalism occurs in giant squid. Denaturing gradient gel electrophoresis was used to screen for less common DNA types, revealing a high frequency of PCR-generated false alleles, but no additional prey species. PMID:15743905

Deagle, B E; Jarman, S N; Pemberton, D; Gales, N J

2005-03-02

482

RF Amplifiers Based on DC SQUID for 3-4 GHz Band  

NASA Astrophysics Data System (ADS)

DC SQUID based RF Amplifiers (SRFAs) are known to dissipate very little power and can be integrated on-chip with existing micro-fabricated circuits for low-noise, low temperature measurements. The SRFA chip has 4 independent channels, which amplify at different signal frequencies and have integrated output filters, which prevent the leakage of high frequency resonances associated with the Josephson frequency. A compact two-layer input signal coil is integrated with the washer of the SQUID (L=20 pH) and planar capacitors for tuned frequency and impedance matching. The input reflected power is further reduced using proven balanced configuration on the SQUID. The shunt resistors are made from a multilayer film Ti(2 nm)/Pd(55 nm)/Ti(2 nm), which allow the SRFA to operate down to 0.4 K. Low-noise SRFAs have been tested with an operating frequency range of 3-4 GHz.

Prokopenko, G. V.; Osborn, K. D.; Shitov, S. V.; Maezawa, M.; Sirois, A. J.; Cicak, K.; Simmonds, R. W.

2006-03-01

483

Characterization of magnetite nanoparticles for SQUID-relaxometry and magnetic needle biopsy  

PubMed Central

Magnetite nanoparticles (Chemicell SiMAG-TCL) were characterized by SQUID-relaxometry, susceptometry, and TEM. The magnetization detected by SQUID-relaxometry was 0.33% of that detected by susceptometry, indicating that the sensitivity of SQUID-relaxometry could be significantly increased through improved control of nanoparticle size. The relaxometry data were analyzed by the moment superposition model (MSM) to determine the distribution of nanoparticle moments. Analysis of the binding of CD34-conjugated nanoparticles to U937 leukemia cells revealed 60,000 nanoparticles per cell, which were collected from whole blood using a prototype magnetic biopsy needle, with a capture efficiency of >65% from a 750 µl sample volume in 1 minute.

Adolphi, Natalie L.; Huber, Dale L.; Jaetao, Jason E.; Bryant, Howard C.; Lovato, Debbie M.; Fegan, Danielle L.; Venturini, Eugene L.; Monson, Todd C.; Tessier, Trace E.; Hathaway, Helen J.; Bergemann, Christian; Larson, Richard S.; Flynn, Edward R.

2009-01-01

484

A post-SQUID ac amplifier aimed for multiplexed detector readouts  

NASA Astrophysics Data System (ADS)

We have built a room temperature amplifier based on Si JFETs (junction field effect transistors) intended for ac-coupled SQUID (superconducting quantum interference device) readouts, such as in frequency-domain multiplexed transition-edge sensor systems. The amplifier operates at 5 MHz centre frequency where it has the measured noise temperature of 27 K for a 60 ? load, which includes the noise from the active termination and the room temperature transformer. When it was driven from a SQUID with an on-chip matching transformer, flux noise of 0.45 ??0 Hz-1/2 was obtained. Additionally, we consider the potential of the recently introduced SiGe bipolar transistors for the same application. The dynamic range considerations for SQUID multiplexers, which require the use of an amplifier with a low noise temperature, are briefly discussed.

Kiviranta, Mikko; Virtanen, Antti; Seppä, Heikki; Penttilä, Jari; Hassel, Juha; Helistö, Panu

2006-05-01

485

Dispersive readout of a flux qubit using a microstrip SQUID amplifier  

NASA Astrophysics Data System (ADS)

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. We demonstrate a dispersive readout scheme in which a three junction aluminum flux qubit is inductively coupled to a 1-2 GHz oscillator formed by a capacitively shunted SQUID. The SQUID in this readout oscillator acts as a nonlinear, flux-dependent inductor so that the oscillator resonance frequency depends on the state of the qubit. Readout is performed by microwave reflectometry; the reflected signal is amplified using a microstrip SQUID amplifier (MSA) with a noise temperature of a few hundred millikelvin. This noise temperature is an order of magnitude lower than that of the HEMT (high electron mobility transistor) amplifier that follows the MSA. We report measurements in both the linear (weak drive) and the bistable (strong drive) oscillator regimes.

Hoskinson, E. M.; Slichter, D. H.; Johnson, J. E.; Macklin, C.; Naaman, O.; Clarke, John; Siddiqi, I.

2010-03-01