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1

[Trace elements in the statoliths of neon flying squid, Ommastrephes bartramii in the Northwest Pacific Ocean].  

PubMed

Statolith is one of the most important hard tissues of cephalopods which is widely used in the research of fisheries ecology including population structure, life history reconstruction and so on. Trace elements of 18 statoliths of neon flying squid Ommastrephes bartramii collected in the Northwest Pacific Ocean in 2007 by Chinese jigging fishing fleets were analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The results indicated that the statoliths of O. bartramii mainly contained 55 elements, and calcium (Ca), strontium (Sr), sodium (Na), phosphorus (P), potassium (K), silicon (Si), magnesium (Mg), boron (B), iron (Fe), barium (Ba) were the 10 most abundant elements. The analysis of variance showed that there was no significant difference in each element distribution between different sexual squid except for P, Si and B. Significant differences existed in the contents of Sr and Na but no significant difference was found in the contents of Ca, P, K, Si, Mg, B, Fe and Ba between different hatching populations. There were significant differences in the contents of Ca, Sr, Na, P, Mg and Ba, but no significant difference was found in the contents of K, Fe, B and Si in the statoliths among different growth zones. This study presented Sr and Na could be the best two trace elements used in the research on the population structure and life history reconstruction for O. bartramii. PMID:25509097

Lu, Hua-Jie; Chen, Xin-Jun; Ma, Jin

2014-08-01

2

Stock assessment of the autumn cohort of neon flying squid ( Ommastrephes bartramii) in the North Pacific based on past large-scale high seas driftnet fishery data  

Microsoft Academic Search

In the high seas of the North Pacific, large-scale squid driftnet fisheries targeted the autumn cohort of neon flying squid (Ommastrephes bartramii) from May to mid-September. Total annual catches during 1982–1992 ranged from 102,000 to 209,000t (149,000t on average). To assess the effect of intensive commercial driftnet fishing on this cohort, we assessed the stock based on past driftnet fishing

Taro Ichii; Kedarnath Mahapatra; Hiroshi Okamura; Yoshihiro Okada

2006-01-01

3

Fishery biology of jumbo flying squid Dosidicus gigas off Costa Rica Dome  

NASA Astrophysics Data System (ADS)

The jumbo flying squid ( Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome (4°-11°N, 90°-100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°-9°N and 91°-94°W and by 6°30'-7°30'N and 96°-97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29°C. The sex ratio of the total catch was 3.75:1 (female: male). The mantle length of the squid ranged from 211 to 355 mm (male) and from 204 to 429 mm (female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length (mm) and body weight (g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size (mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs (70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.

Chen, Xinjun; Li, Jianghua; Liu, Bilin; Li, Gang; Lu, Huajie

2014-06-01

4

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.

5

Identification of the first major allergen of a squid (Todarodes pacificus)  

Microsoft Academic Search

Background: In Japan, squid is an important seafood, and some patients with food allergies are sensitive to squid. There has been no report, however, describing the major allergens of squid. Objective: To characterize squid allergens, we isolated a major allergen from the Pacific flying squid (Todarodes pacificus) and compared it with a major allergen from a shrimp (Penaeus orientalis). Methods:

Hiroshi Miyazawa; Hiromi Fukamachi; Yoshimasa Inagaki; Gerald Reese; Carolyn B. Daul; Samuel B. Lehrer; Sakae Inouye; Masahiro Sakaguchi

1996-01-01

6

Influence of El Nin~o/La Nin~a on the western winterspring cohort of neon flying squid (Ommastrephes bartramii) in the  

E-print Network

of the autumn cohort, and a western and a central-eastern stock of the winter­ spring cohort (Nagasawa et al (Figure 2; Bower, 1996; Nagasawa et al., 1998; Yatsu et al., 1998). They can be found from subtropical

Chen, Yong

7

FLIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flies constitute a major group of nuisance species world wide in rural and urban situations. The public and health care officials can become more aware of the potential risks from flies and other urban pests by compiling the available information into an easily readable book form. Scientists from ...

8

Squid Lab  

NSDL National Science Digital Library

This online handbook features a downloadable PDF of pre-and post-visit activities for the Squid Lab, a traveling outreach program hosted by the National Aquarium in Baltimore. The hands-on activities and student sheets may be incorporated into any life science classroom. The Squid Lab begins with an overview of the cephalopods, with a particular emphasis on squid. The overall anatomy of the squid is also discussed to provide students with a preview of what they will see when the dissection begins. Students will learn about the adaptations, defense mechanisms, feeding habits, predators and reproductive strategies of squid. Step by step directions are given to guide the students through the dissection.

Baltimore, National A.

9

Squid Lab  

NSDL National Science Digital Library

This online handbook features a downloadable PDF of pre-and post-visit activities for the Squid Lab, a traveling outreach program hosted by the National Aquarium in Baltimore. The hands-on activities and student sheets may be incorporated into any life science classroom. The Squid Lab begins with an overview of the cephalopods, with a particular emphasis on squid. The overall anatomy of the squid is also discussed to provide students with a preview of what they will see when the dissection begins. Students will learn about the adaptations, defense mechanisms, feeding habits, predators and reproductive strategies of squid. Step by step directions are given to guide the students through the dissection.

2009-06-17

10

Fly  

NSDL National Science Digital Library

Fly is a seamless way to edit videos quickly and with little fuss, all from your iPhone. This application can be used to make simple edits, dissolve transitions, add split screens, and much more. Additionally, users can videos to four different devices. The site contains several helpful demos and a thorough FAQ area. This version is compatible with all devices running iOS 7.0 and newer.

2014-07-11

11

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

12

Holographic SQUID  

E-print Network

We propose a holographic model of the SQUID (Superconducting QUantum Interference Device) composed of two Josephson junctions connected each other in a circle with the magnetic flux penetrating the circuit of the SQUID and the supercurrents flowing in both Josephson junction. The gravity in this paper is the Einstein-Maxwell-complex scalar field model on the four-dimensional Anti-de Sitter Schwarzschild black brane geometry in which one space direction is compactified into a circle, and we arrange the profile of the coefficient of the time component of the gauge field having the role for the chemical potential of the cooper pair. The magnetic flux is involved by the rewriting of the surface integral of the magnetic field to the contour integral of the gauge field.

Takeuchi, Shingo

2013-01-01

13

Neon K Emission Spectrum  

Microsoft Academic Search

The neon K emission spectrum, excited by direct electron bombardment of the neon gas, has been obtained with photon counting on a single-crystal potassium-acid-phthalate (KAP) planar spectrometer. The measured relative integrated intensity of the alpha'alpha3alpha4 and alpha5alpha6 satellite groups was found to be larger than theoretical prediction, but in accord with the trend of previous comparisons for K satellites of

R. E. Lavilla

1971-01-01

14

City Lights: Vancouver's Neon Heritage  

NSDL National Science Digital Library

Based on a physical exhibit earlier this year and walking tour developed by the city of Vancouver, this site explores the art and science of neon lights. The site is composed of three sections. The first takes visitors through an electronic version of the exhibit, with twenty-nine images which include brief captions. The tour section of the site offers a virtual stroll through neon Vancouver with twenty-three images. Finally, the neon science section explains what neon is and how neon lights are made.

15

Helium Neon Laser  

NSDL National Science Digital Library

This resource, part of the Spectroscopy Lab Suite, illustrates the physics of a Helium-Neon Laser. Students can create energy levels for both the He and Ne atoms. The basic processes for light emission, including collisions and level transitions, are shown. The atomic energy levels and the pumping energy can be adjusted to achieve an output spectrum similar to the measured physical spectrum.

Zollman, Dean

16

SQUIDs for nondestructive evaluation  

Microsoft Academic Search

We attempt a comprehensive review of all published research in nondestructive evaluation (NDE) performed with the superconducting quantum interference device (SQUID) magnetometer since the first work was reported in the mid-1980s. The SQUID is the most sensitive detector of magnetic flux known. The energy sensitivity of the SQUID may make it the most sensitive detector of any kind. The research

W G Jenksy; Amir Kabir

1997-01-01

17

The Squid Challenge.  

ERIC Educational Resources Information Center

Describes an approach to the study of squid that helps students of all ages develop richer ideas about the structure of living things, how living things are adapted to their habitats, and how they interact with other organisms. Highlights include the external and internal features of the squid, squid statements and statistics, and writing…

Guillaume, Andrea M.

1997-01-01

18

Applications of HTSC SQUIDs  

NASA Astrophysics Data System (ADS)

Recently a high temperature superconductor (HTSC)-SQUID has been made with high magnetic field resolution and its application is expected to be practical for many fields. The HTSC-SQUID can work using liquid nitrogen which is handled much more easily than liquid helium, and thus a wide range of HTSC-SQUID applications is expected. This chapter describes recent HTSC-SQUIDs application researchs such as magnetocardiography, biological immunoassay, measurement of ultra low frequency to observe underground activities and a laser-SQUID microscope for LSI chip defects analysis.

Itozaki, H.; Sakuta, K.; Kobayashi, T.; Enpuku, K.; Kasai, N.; Fujinawa, Y.; Iitaka, H.; Nikawa, K.; Hidaka, M.

19

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!

20

In Search of Giant Squid  

NSDL National Science Digital Library

This site, an online exhibition from the Smithsonian Institution's National Museum of Natural History (NMNH), provides a wealth of background information on Giant Squids. The largest invertebrates on the planet, Giant Squids have aroused human curiosity for centuries. This site offers a plethora of general information about squids and includes a long list of squid links as well.

21

Micromechanical Flying Insect Michael Dickinson, Ron Fearing, Dorian Liepmann,  

E-print Network

Wing Wing Wing Wing Body #12;Summary of Wing Motion · Fruit Fly and Most Insects: High Asymmetry, High.e. to accelerate the wings #12;Flying Squid: Pulsating Wing Motion for Low Reynolds Number Flight Wing Motion Wing of Hover Fly Wing Motion = 1/fo V1 Applied Voltage Time Emulation of Elastic Storage by Resonance

California at Berkeley, University of

22

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; Times, The E.

23

Chimeras in SQUID Metamaterials  

E-print Network

Regular lattices comprising Superconducting QUantum Interference Devices (SQUIDs) form magnetic metamaterials exhibiting extraordinary properties, including tuneability, dynamic multistability, and negative magnetic permeability. The SQUIDs in a metamaterial interact through non-local, magnetic dipole-dipole forces, that makes it possible for counter-intuitive dynamic states referred to as {\\em chimera states} to appear; the latter feature clusters of SQUIDs with synchronous dynamics which coexist with clusters exhibiting asynchronous behaviour. The spontaneous appearance of {\\em chimera states} is demonstrated numerically for SQUID metamaterials driven by an alternating magnetic field in which the fluxes threading the SQUID rings are randomly initialized; then, chimera states appear generically for sufficiently strong initial excitations, which exhibit relatively long life-times. The synchronization and metastability levels of the chimera states are discussed in terms of appropriate measures. Given that SQUID metamaterials have been already fabricated and investigated in the lab, the presence of a chimera state could in principle be detected with presently available experimental set-ups.

N. Lazarides; G. Neofotistos; G. P. Tsironis

2014-11-24

24

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

PubMed

Effects of dietary firefly squid on serum and liver lipid levels were investigated. Male Wistar rats were fed a diet containing 5% freeze-dried firefly squid or Japanese flying squid for 2 weeks. There was no significant difference in the liver triacylglycerol level between the control and Japanese flying squid groups, but the rats fed the firefly squid diet had a significantly lower liver triacylglycerol content than those fed the control diet. No significant difference was observed in serum triacylglycerol levels between the control and firefly squid groups. The rats fed the firefly squid had a significantly lower activity of liver glucose-6-phosphate dehydrogenase compared to the rats fed the control diet. There was no significant difference in liver fatty acid synthetase activity among the three groups. Hepatic gene expression and lipogenic enzyme activity were investigated; a DNA microarray showed that the significantly enriched gene ontology category of down-regulated genes in the firefly squid group was "lipid metabolic process". The firefly squid group had lower mRNA level of glucose-6-phosphate dehydrogenase compared to the controls. These results suggest that an intake of firefly squid decreases hepatic triacylglycerol in rats, and the reduction of mRNA level and enzyme activity of glucose-6-phosphate dehydrogenase might be related to the mechanisms. PMID:25452266

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

2014-01-01

25

In Brief. ... Of Squid, Tarpon,  

E-print Network

In Brief. ... Of Squid, Tarpon, Blue Crab, and King Salmon · . . . During the first 9 months Russian trawler, the Argus, failed to find commercial quantities of squid off the southeastern U.S. coast Resources Department reports. How- ever, the Russians did find just enough squid to encourage them to look

26

SQUID magnetocardiography: status and perspectives  

Microsoft Academic Search

Magnetocardiography (MCG), the magnetic equivalent to electrocardiography (ECG), is one of the most promising major applications of SQUID systems. Recent advances in SQUID-system technology such as improved noise suppression techniques, better field sensitivity (in particular for HTS SQUIDs), real time options, vector magnetometers and novel signal analysis approaches have appreciably reduced the technical constraints that hindered until recently the implementation

Hans Koch

2001-01-01

27

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).

28

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

29

Dc SQUID small signal analysis  

SciTech Connect

This paper presents a Small Signal Analysis for the dc SQUID (Superconducting Quantum Interference Device). This analysis involves the linearization of the SQUID equations for a given flux and current bias. Considering the SQUID to be a two port device, an impedance matrix can be determined for a SQUID coupled to a general input circuit. Also, the two intrinsic noise sources referred to the input are computed. One advantage of this analysis over other models of the dc SQUID is that an analytic expression can be determined for the cross-correlation power spectral density of the noise sources. These results should be useful in determining the signal-to-noise ratio of low-noise SQUIDs for a given application. Other differences and similarities of the Small Signal Analysis to other dc SQUID models are discussed.

Carroll, K.R. (Maryland Univ., College Park, MD (United States). Dept. of Physics and Astronomy)

1991-03-01

30

Neon isotopes in submarine basalts  

Microsoft Academic Search

Very large neon isotopic anomalies have been accurately measured in mid-ocean ridge basalt glassy samples from diverse locations worldwide. Values for 20Ne\\/22Ne range up to ~ 13 and 21Ne\\/22Ne values range up to ~ 0.07 (present atmospheric values are 20Ne\\/22Ne = 9.8 and 21Ne\\/22Ne = 0.029). The data are highly correlated in the 20Ne\\/22Ne-21Ne\\/22Ne diagram, independent of sample location. Loihi

Philippe Sarda; Thomas Staudacher; Claude J. Allègre

1988-01-01

31

Low-noise SQUID  

SciTech Connect

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

Dantsker, E.; Clarke, J.

2000-02-08

32

The microstrip SQUID amplifier  

NASA Astrophysics Data System (ADS)

A Superconducting Quantum Interference Devices (SQUIDS) can operate at frequencies up to several GHz and can be cooled to less than 100 mK. Such characteristics make the SQUID---a flux-to-voltage transducer---an excellent candidate for use as a low-noise rf amplifier. Coupling of input signals of frequencies larger than 200 MHz, however, has been limited by the parasitic capacitance between the input coil and SQUID body. We present experimental observations of a do SQUID-based rf amplifier which circumvents this problem by incorporating the input coil as a microstrip resonator. The microstrip input configuration uses the capacitance and inductance of the input coil to form a resonant cavity capable of operating up to several GHz. The input signal is applied between the SQUID body and one end of the input coil, while the other end of the coil is left open. We present data from microstrip SQUID amplifiers with gains of up to 22 dB at 900 MHz. In order to understand the gain and input impedance of the microstrip SQUID in greater detail, we made and studied a 1:190 scale analog patterned on a double-sided printed circuit board consisting of copper deposited on a kapton sheet. The measured input impedance of the analog SQUID is successfully modeled by describing the microstrip input as a low-loss transmission line. When operated with the slit in the copper washer ground plane shorted, the input coil behaves exactly like a linear resonator with the resonant frequency given by f = 1/2?(L 0C0)1/2, where L0 and C0 are the inductance and capacitance per unit length and ? is the coil length. With the slit in the washer left open, the inductance of the input coil is significantly altered in a manner partially consistent with the Ketchen-Jaycox model in which the reflected inductance of the input coil is Li = n2L, where L is the inductance of the washer loop and n is the number of turns in the coil. We present input impedance measurements on microstrip SQUIDs cooled to 4.2 K. The low-loss transmission line model fits the real and imaginary parts of the microstrip input impedance very accurately. We map the low-loss transmission line model into an equivalent parallel RLC circuit in which a resistance R, inductance L, and capacitance C are calculated from the characteristic impedance and attenuation factor determined from the fits to the input impedance data. Using this equivalent RLC circuit, we model the microstrip SQUID and input network with a lumped circuit model which accurately predicts the observed gain of the amplifier. We find that gain is maximized when the input circuit is critically matched, with the imaginary part of the input impedance summing to zero and the real part equal to the 50O resistance of the coaxial input line. Thus, the full signal power is transmitted into the microstrip resonator and is dissipated in the equivalent resistance R.

Therrien, Roy

33

Dissect Your Squid and Eat It Too!  

ERIC Educational Resources Information Center

Introduces a science lab activity in which students dissect fresh squids in groups of four and observe the anatomy. Parent volunteers cook the squid mantle for kids to taste. Includes directions for squid dissection. (YDS)

McGinnis, Patricia

2001-01-01

34

SQUID With Integral Flux Concentrator  

NASA Technical Reports Server (NTRS)

In improved superconducting quantum interference device (SQUID), change in size and shape of superconducting ring improves coupling to external signal coil and eases coil-positioning tolerances. More rugged and easier to manufacture than conventional SQUID's with comparable electrical characteristics. Thin-film superconducting flux concentrator utilizes Meissner effect to deflect magnetic field of signal coil into central hole of SQUID. Used in magnetometers, ammeters, analog-to-digital converters, and related electronic applications in which high signal-to-noise ratios required.

Peters, Palmer N.; Sisk, Robert C.

1989-01-01

35

Small scale demand type neon liquefaction plant  

NASA Technical Reports Server (NTRS)

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 LH2 (1989 prices). A neon liquefaction plant has been designed and constructed to capture, purify, and refrigerate the neon boil-off from calorimetry experiments. Recycling the neon reduces operating costs to approximately $20/l. The system consists of a purification section, a heat exchanger, LNe and LH2 storage dewars, and a fully automated control system. After purification, neon is liquified in the heat exchanger by LH2 flowing countercurrently through stainless steel cooling coils. Hydrogen flow is automatically adjusted to keep the neon at its normal saturation temperature, 27 K. The liquid neon is then stored in a dewar placed directly below the heat exchanger.

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

1990-01-01

36

Small scale demand type neon liquefaction plant  

NASA Astrophysics Data System (ADS)

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 LH2 (1989 prices). A neon liquefaction plant has been designed and constructed to capture, purify, and refrigerate the neon boil-off from calorimetry experiments. Recycling the neon reduces operating costs to approximately $20/l. The system consists of a purification section, a heat exchanger, LNe and LH2 storage dewars, and a fully automated control system. After purification, neon is liquified in the heat exchanger by LH2 flowing countercurrently through stainless steel cooling coils. Hydrogen flow is automatically adjusted to keep the neon at its normal saturation temperature, 27 K. The liquid neon is then stored in a dewar placed directly below the heat exchanger.

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

37

Graphoepitaxial high-Tc SQUIDs  

NASA Astrophysics Data System (ADS)

The fabrication process and physical properties of graphoepitaxially engineered high-Tc direct current superconducting quantum interferometer devices (DC SQUIDs) are studied. Double buffer layers, each comprising a graphoepitaxial seed layer of YBa2Cu3O7-x and an epitaxial blocking layer of SrTiO3, were deposited over textured step edges on (001) surfaces of MgO substrates. Scanning electron microscopy and high-resolution transmission electron microscopy were used to investigate the microstructural properties of DC SQUIDs with graphoepitaxial Josephson junctions. Both direct coupled and inductively coupled high-Tc DC SQUIDs with graphoepitaxial step edge junctions and flux transformers were studied.

Faley, M. I.; Meertens, D.; Poppe, U.; Dunin-Borkowski, R. E.

2014-05-01

38

Design of a Large Bandwidth Scanning SQUID Microscope using a Cryocooled Hysteretic dc SQUID .  

E-print Network

??I present the design and analysis of a large bandwidth scanning Superconducting Quantum Interference Device (SQUID) microscope. Currently available SQUID microscopes are limited to detecting… (more)

Kwon, Soun Pil

2006-01-01

39

Biomagnetic susceptometer with SQUID instrumentation  

SciTech Connect

This paper discusses the use of a new SQUID magnetometer for noninvasive measurements of hepatic (liver) iron stores. Placement of the SQUID, detection coil, and magnetie in the dewar vacuum region significantly reduced system noise. In addition, the system incorporates multiple magnets and detection coils which may allow the discrimination of the surface skin layer from the deeper (weaker signal) true liver iron concentration. Measurements indicate an instrumental noise level {lt} 20 {mu}g/g of equivalent iron concentration.

Paulson, D.N.; Fagaly, R.L.; Toussaint, R.M. (Biomagnetic Technologies, Inc., San Diego, CA (US)); Fisher, R. (Hamburg Univ. (Germany))

1991-03-01

40

dc SQUID: Noise and optimization  

Microsoft Academic Search

A computer model is described for the dc SQUID in which the two Josephson junctions are nonhysteretic, resistively shunted tunnel junctions. In the absence of noise, current-voltage(I–V) characteristics are obtained as functions of the applied flux, Fa, SQUID inductanceL, junction critical currentI0, and shunt resistanceR. The effects of asymmetry inL, I0, andR are discussed.I–V characteristics, flux-voltage transfer functions, and low-frequency

Claudia D. Tesche; John Clarke

1977-01-01

41

Flying wings / flying fuselages  

NASA Technical Reports Server (NTRS)

The present paper has documented the historical relationships between various classes of all lifting vehicles, which includes the flying wing, all wing, tailless, lifting body, and lifting fuselage. The diversity in vehicle focus was to ensure that all vehicle types that map have contributed to or been influenced by the development of the classical flying wing concept was investigated. The paper has provided context and perspective for present and future aircraft design studies that may employ the all lifting vehicle concept. The paper also demonstrated the benefit of developing an understanding of the past in order to obtain the required knowledge to create future concepts with significantly improved aerodynamic performance.

Wood, Richard M.; Bauer, Steven X. S.

2001-01-01

42

Chromophores in photoproteins of a glowing squid and mollusk.  

PubMed

Bioluminescence is a chemical reaction process for light emission in vivo. An organic substance is normally oxidized in the protein to obtain the energy required for the light emission. Determination of the structure of the substance is one of the most important parts of bioluminescent research. Photoproteins of a flying squid and a mollusk contain chromophores that are formed by connecting an apo-protein and dehydrocoelenterazine. The chromophore has a chemical structure that can emit light in a photoprotein. The structural analysis of the chromophores in the photoproteins is described. PMID:25035971

Kuse, Masaki

2014-01-01

43

Performance of a double dc SQUID magnetometer  

SciTech Connect

This paper presents a magnetic flux sensing device that is made by using two dc Squids. The dc Squids are of similar characteristics, magnetically coupled by a common coil and are turned into the voltage state by a single dc current source. As the dc Squids are magnetically coupled, the magnetic flux noise generated by one of the dc Squids is sensed by the other one and vice versa. Then by making a differential measurement across both dc Squids, the magnetic flux noise detected by the dc Squids can be added either constructively or destructively. This means the magnetic flux noise cancellation is possible as it is demonstrated experimentally. The double dc Squid configuration can also be used in the add flux noise mode, case in which there is no loss of performance when comparing with what is possible to obtain with a single dc Squid.

Casas, J.; Miyoamoto, N.; Nakane, H.; Goto, E. (Research Development Corp. of Japan, I-280 Higashi Koigakubo, Kokubunji, Tokyo 185 (JP))

1991-03-01

44

SQUID magnetometers for low-frequency applications  

Microsoft Academic Search

We present a novel formulation for SQUID operation, which enables us to evaluate and compare the sensitivity and applicability of different devices. SQUID magnetometers for low-frequency applications are analyzed, taking into account the coupling circuits and electronics. We discuss nonhysteretic and hysteretic single-junction rf SQUIDs, but the main emphasis is on the dynamics, sensitivity, and coupling considerations of dc-SQUID magnetometers.

Tapani Ryhänen; Heikki Seppä; Risto Ilmoniemi; Jukka Knuutila

1989-01-01

45

SQUID holder with high magnetic shielding  

SciTech Connect

We discuss a SQUID holder designed for high magnetic shielding. We show how to estimate the attenuation of the magnetic field from the normal magnetic modes for an approximate geometry. The estimate agrees satisfactorily with the attenuation measured with a commercial rf SQUID installed in the holder. The holder attenuates external magnetic fields by more than 10{sup 9} at the SQUID input. With the SQUID input shorted, the response to external fields is 10{sup {minus}5} {Phi}{sub 0}/G.

Rigby, K.W.; Marek, D.; Chui, T.C.P. (Department of Physics, Stanford University, Stanford, California 94305 (US))

1990-02-01

46

SQUID holder with high magnetic shielding  

NASA Technical Reports Server (NTRS)

A SQUID holder designed for high magnetic shielding is discussed. It is shown how to estimate the attenuation of the magnetic field from the normal magnetic modes for an approximate geometry. The estimate agrees satisfactorily with the attenuation measured with a commercial RF SQUID installed in the holder. The holder attenuates external magnetic fields by more than 10 to the 9th at the SQUID input. With the SQUID input shorted, the response to external fields is 0.00001 Phi(0)/G.

Rigby, K. W.; Marek, D.; Chui, T. C. P.

1990-01-01

47

A TDMA Hybrid SQUID Multiplexer  

NASA Astrophysics Data System (ADS)

We have developed a multiplexed read-out for transition-edge sensors (TES) based on a hybrid time- and frequency-domain basis set, similar to that used in time-division multiple-access (TDMA) mobile phones. The hybrid basis set uses bandwidth more efficiently than microwave frequency-division SQUID multiplexing, making it possible to multiplex more detectors in each output line. The high open-loop bandwidth provided by our SQUID TDMA system also makes it possible to multiplex large arrays of fast, high dynamic range detectors such as fast x-ray calorimeters. In this approach, we embed the second-stage SQUID amplifier of our standard time-division multiplexer in an impedance matching circuit coupled to a broadband cryogenic high electron mobility transistor (HEMT) in a microwave reflectometer configuration. The input signals are flux coupled into the first-stage SQUID amplifiers whose signals are time-division multiplexed into the second-stage SQUID. At room temperature, the signal from the HEMT is mixed down to dc for analysis and further signal processing.

Reintsema, C. D.; Beall, J.; Doriese, W.; Duncan, W.; Ferreira, L.; Hilton, G. C.; Irwin, K. D.; Schmidt, D.; Ullom, J.; Vale, L.; Xu, Y.

2008-05-01

48

Paleomagnetic Analysis Using SQUID Microscopy  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

49

A 37 channel DC SQUID magnetometer system  

Microsoft Academic Search

A 37-channel DC SQUID magnetometer system has been built for biomagnetic studies. The SQUID loop of each magnetometer serves as the active sensing element, thereby eliminating the need for flux coupling circuits. The magnetometers are located ≃3 cm above the outer dewar bottom. The SQUIDs are directly coupled to a highly simplified readout electronics using only five wires per channel;

H. Koch; R. Cantor; D. Drung; S. N. Erne; K. P. Matthies; M. Peters; T. Ryhanen; H. J. Scheer; H. D. Hahlbohm

1991-01-01

50

The Philippines Squid Fishery: A Review  

E-print Network

The Philippines Squid Fishery: A Review ANICETO M. HERNANDO, Jr. and EFREN ED. C. FLORES Aniceto M not necessarily reflect the position of the National Marine Fisheries Service, NOAA. Introduction Squids were increasing squid production, it cannot meet the increasing demand of local, national, and foreign markets

51

Editor's Comments In Defense of the Squid  

E-print Network

Editor's Comments In Defense of the Squid · In the oveillher numher \\11 IIfFR, I made ~ome remar's tennis shoes and then tell me that you prefer tennl shoes to raw squid." My only alibi is that I have never- in either hemisphere-eaten squid pre- pared this way. Be willing to give it a try. though. · W. L

52

Experimental Squid Jigging Off the Washington Coast  

E-print Network

Experimental Squid Jigging Off the Washington Coast ROGER W. MERCER and MICHELE SUCY Introduction Service was contacted by Capta in Jerry Sweeney of the salmon charter vessel Tres Cher in regard to squid of existing literature on squid yielded several pieces of information which indicated some potential

53

Tracking Electromagnetic Energy With SQUIDs  

NASA Technical Reports Server (NTRS)

A superconducting quantum interference device (SQUID) is a gadget used to measure extremely weak signals, specifically magnetic flux. It can detect subtle changes in energy, up to 100 billion times weaker than the electromagnetic energy required to move a compass needle. SQUIDs are used for a variety of testing procedures where extreme sensitivity is required and where the test instrument need not come into direct contact with the test subject. NASA uses SQUIDs for remote, noncontact sensing in a variety of venues, including monitoring the Earth s magnetic field and tracking brain activity of pilots. Scientists at NASA s Goddard Space Flight Center have been making extensive use of this technology, from astrophysical research, to tracking the navigational paths of bees in flight to determine if they are using internal compasses. These very sensitive measurement devices have a wide variety of uses within NASA and even more uses within the commercial realm.

2005-01-01

54

A holographic model of SQUID  

NASA Astrophysics Data System (ADS)

We construct a holographic model of superconducting quantum interference device (SQUID) in the Einstein-Maxwell-complex scalar theory with a negative cosmological constant. The SQUID ring consists of two Josephson junctions which sit on two sides of a compactified spatial direction of a Schwarzschild-AdS black brane. These two junctions interfere with each other and then result in a total current depending on the magnetic flux, which can be deduced from the phase differences of the two Josephson junctions. The relation between the total current and the magnetic flux is obtained numerically.

Cai, Rong-Gen; Wang, Yong-Qiang; Zhang, Hai-Qing

2014-01-01

55

A holographic model of SQUID  

E-print Network

We construct a holographic model of superconducting quantum interference device (SQUID) in the Einstein-Maxwell-complex scalar theory with a negative cosmological constant. The SQUID ring consists of two Josephson junctions which sit on two sides of a compactified spatial direction of a Schwarzschild-AdS black brane. These two junctions interfere with each other and then result in a total current depending on the magnetic flux, which can be deduced from the phase differences of the two Josephson junctions. The relation between the total current and the magnetic flux is obtained numerically.

Cai, Rong-Gen; Zhang, Hai-Qing

2013-01-01

56

Development and commercialization of high Tc SQUID  

NASA Astrophysics Data System (ADS)

A high Tc SQUID has been developed and is going to be commercialized soon. It features low cost operation with liquid nitrogen coolant and easy operation. Therefore the high Tc SQUID becomes more useful for us than a low Tc SQUID operating with liquid helium. The high Tc SQUID was firstly commercialized by Conductus in California. This was a very pioneer work. Four companies in the US, five companies in Europe and Sumitomo Electric in Japan are now selling it commercially. These commercial SQUIDs are small equipments used for application research in laboratories. Applications are medical diagnosis, nondestructive testing, biomagnetic analysis, geological survey and so on. The high Tc SQUID is a frontier of superconductor electronics. Active research in the development of high Tc SQUID is being conducted worldwide and its commercialization is expected soon.

Itozaki, Hideo

2001-09-01

57

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

58

Rearing of Cuttlefishes and Squids  

Microsoft Academic Search

WE have succeeded (through improving the feed during the earlier stages after hatching) in rearing three species of the cuttlefish (Sepia esculenta Hoyle, Sepia subaculeata Sasaki and Sepiella maindroni de Rochebrune) and two species of the squid (Sepioteuthis lessoniana Lesson and Euprymna beryii Sasaki)1. The main points to note in rearing these animals are as follows:

Sang Choe; YASUO OHSHIMA

1963-01-01

59

Bright Squid Found In Hawaii  

NSDL National Science Digital Library

This 2004 CBS news article gives a brief summary of the initial discovery of a Hawaiian bobtail squid with reflective plates that form a built-in light, which is thought to confuse predators. The article also discusses possible mechanisms for the light production.

Randolph E. Schmid

60

How the SQUID was born  

NASA Astrophysics Data System (ADS)

I was asked to speak about the discovery and invention of the SQUID at the International Superconducting Electronics Conference (ISEC) 2005 banquet. This narrative is based on my personal recollections of the sequence of events and the motivations. I have edited the text and added figures for clarity. Although it is an old story, it may contain some useful lessons.

Silver, Arnold H.

2006-05-01

61

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

62

MFR PAPER 1257 Care and Maintenance of Squid Quality  

E-print Network

MFR PAPER 1257 Care and Maintenance of Squid Quality INTRODUCTION The squid resources in the proper handling of squid at sea and through the processing and dis- tribution stages. Typically, squid for squid is primarily a small-boat fishery, and the catch is sometimes not iced at sea. In southern New

63

Improved Sensing Coils for SQUIDs  

NASA Technical Reports Server (NTRS)

An improvement in the design and fabrication of sensing coils of superconducting quantum interference device (SQUID) magnetometers has been proposed to increase sensitivity. It has been estimated that, in some cases, it would be possible to increase sensitivity by about half or to reduce measurement time correspondingly. The pertinent aspects of the problems of design and fabrication can be summarized as follows: In general, to increase the sensitivity of a SQUID magnetometer, it is necessary to maximize the magnetic flux enclosed by the sensing coil while minimizing the self-inductance of this coil. It is often beneficial to fabricate the coil from a thicker wire to reduce its self-inductance. Moreover, to optimize the design of the coil with respect to sensitivity, it may be necessary to shape the wire to other than a commonly available circular or square cross-section. On the other hand, it is not practical to use thicker superconducting wire for the entire superconducting circuit, especially if the design of a specific device requires a persistent-current loop enclosing a remotely placed SQUID sensor. It may be possible to bond a thicker sensing-coil wire to thinner superconducting wires leading to a SQUID sensor, but it could be difficult to ensure reliable superconducting connections, especially if the bonded wires are made of different materials. The main idea is to mold the sensing coil in place, to more nearly optimum cross sectional shape, instead of making the coil by winding standard pre-fabricated wire. For this purpose, a thin superconducting wire loop that is an essential part of the SQUID magnetometer would be encapsulated in a form that would serve as a mold. A low-melting-temperature superconducting metal (e.g., indium, tin, or a lead/tin alloy) would be melted into the form, which would be sized and shaped to impart the required cross section to the coil thus formed.

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

2007-01-01

64

Diffusion of neon in white dwarf stars.  

PubMed

Sedimentation of the neutron rich isotope 22Ne may be an important source of gravitational energy during the cooling of white dwarf stars. This depends on the diffusion constant for 22Ne in strongly coupled plasma mixtures. We calculate self-diffusion constants D(i) from molecular dynamics simulations of carbon, oxygen, and neon mixtures. We find that D(i) in a mixture does not differ greatly from earlier one component plasma results. For strong coupling (coulomb parameter ?> few), D(i) has a modest dependence on the charge Z(i) of the ion species, D(i)?Z(i)(-2/3). However, D(i) depends more strongly on Z(i) for weak coupling (smaller ?). We conclude that the self-diffusion constant D(Ne) for 22Ne in carbon, oxygen, and neon plasma mixtures is accurately known so that uncertainties in D(Ne) should be unimportant for simulations of white dwarf cooling. PMID:21230741

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

2010-12-01

65

High-{Tc} rf SQUID magnetometers  

SciTech Connect

The discovery of high temperature superconductors has revived the interest in rf SQUIDS, which, in the case of conventional superconductors had been surpassed in performance by the dc SQUID. Several advantages are offered by the rf SQUID, like the requirement for only a single weak link and a low 1/f noise. With high bias frequencies (> 100 MHz) it is possible to obtain flux noise values comparable to dc SQUIDS. At present, HTS rf SQUIDs offer a field sensitivity of less than 100 fT/{radical}Hz ({at} 1 Hz). This is already sufficient for a number of serious applications. This paper reviews recent developments towards practical rf SQUIDs made of high-{Tc} superconductors.

Mueck, M. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Schicht- und Ionentechnik

1994-12-31

66

Microwave-free manipulation of a SQUID qubit  

E-print Network

Microwave-free manipulation of a SQUID qubit S. Poletto1, J. Lisenfeld1, A. Lukashenko1 M/2 0=2.07·10-15 Wb 1-junction SQUID (rf SQUID) #12;I Vs JJ with tunable critical current 0 2I0 I0 l I0 s V I 2I0 s=0 2-junction SQUID (dc SQUID) #12;Qubit (double SQUID) x For x = 0/2 the potential

Fominov, Yakov

67

Binary collision model for neon Auger spectra from neon ion bombardment of the aluminum surface  

NASA Technical Reports Server (NTRS)

A model is developed to account for the angle-resolved Auger spectra from neon ion bombardment of the aluminum surface recently obtained by Pepper and Aron. The neon is assumed to be excited in a single asymmetric neon-aluminum-collision and scattered back into the vacuum where it emits an Auger electron. The velocity of the Auger electron acquires a Doppler shift by virtue of the emission from a moving source. The dependence of the Auger peak shape and energy on the incident ion energy, angle of incidence and on the angle of Auger electron emission with respect to the surface is presented. Satisfactory agreement with the angle resolved experimental observations is obtained. The dependence of the angle-integrated Auger yield on the incident ion energy and angle of incidence is also obtained and shown to be in satisfactory agreement with available experimental evidence.

Pepper, S. V.

1986-01-01

68

Mobile high- Tc DC SQUID magnetometer  

NASA Astrophysics Data System (ADS)

By optimizing the designing, we made a small size and low noise high- Tc DC SQUID readout electronics with the modulation frequency of 80 kHz. The white flux noise was about 30 ? ?0/ Hz when Sumitomo high- Tc DC SQUID sensor was used. We also proved mobile high- Tc DC SQUID magnetometer was feasible. By using a special compensation method, the SQUID magnetometer could keep locking when it swung about 20° in the earth field. Using this system and eddy-current nondestructive evaluation method, we successfully detected the defect in ferromagnetic material.

He, D. F.; Yoshizawa, M.

2003-05-01

69

SQUID detected NMR and NQR  

Microsoft Academic Search

The dc Superconducting QUantum Interference Device (SQUID) is a sensitive detector of magnetic flux, with a typical flux noise of the order 1 ??0 Hz?1\\/2 at liquid helium temperatures. Here ?0=?\\/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

Matthew P. Augustine; Dinh M. TonThat; John Clarke

1998-01-01

70

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.

0000-00-00

71

Paleomagnetism with the SQUID Microscope  

NASA Astrophysics Data System (ADS)

Rocks should preserve stable remanent magnetizations with useful directional and intensity information at levels down to ~10-15 Am2, about 1000 times below that of the noise level on today's best superconducting moment magnetometers. As a result, a more sensitive magnetometer could dramatically expand the range and variety of rock types amenable to paleomagnetic analysis. Just such an instrument is now on the horizon: the superconducting quantum interference device (SQUID) Microscope, designed by F. Baudenbacher and J. Wikswo of Vanderbilt University. The SQUID Microscope makes a map of the vertical component of the magnetic field above the surface of a sample held at room temperature and pressure. It achieves this with a spatial resolution of 250 ? m and a moment sensitivity 10,000 times that of the most recent 2G Enterprises Superconducting Rock Magnetometer (2G SRM). It can therefore provide data with a resolution comparable with that of other common petrographic techniques such as optical and electron microscopy. A major reason that the SQUID Microscope has such high sensitivity and resolution compared to the 2G SRM is that it has a much smaller pickup coil. Smaller coils are more sensitive to dipoles because they encompass less of the sample's fringing fields oriented in the opposite sense to its magnetization. Smaller coils also encompass a smaller area above the sample and so also provide higher spatial resolution. Our initial collaborative work on 30-? m thin sections of Martian meteorite ALH84001 has already demonstrated that SQUID Microscopy will enable a whole a new class of paleomagnetic analyses. Conglomerate, baked contact, and fold tests can be performed on extremely small spatial scales, vastly expanding the utility of these critical geological field tests of magnetic stability. A suite of rock-magnetic and paleomagnetic experiments can be done on individual grains in standard petrographic thin sections at very high rates, allowing the observed magnetic components to be matched with the minerals that are present. To be useful for palemagnetic studies, a scheme is needed to invert the SQUID Microscope's output data (a spatial grid of vertical components of the magnetic field) into a three-dimensional vector magnetization pattern within the sample. This problem is similar to that encountered in the inversion of aeromagnetic field data to a map of lithosphere magnetization. We have implemented an equivalent source scheme solved by conjugate gradient analysis and singular value decomposition that gives robust inversions for rock samples with spatially separated dipolar sources.

Weiss, B. P.; Baudenbacher, F. J.; Wikswo, J. P.; Kirschvink, J. L.

2002-05-01

72

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

73

A series array of DC SQUIDs  

Microsoft Academic Search

A series array of 100 DC SQUIDs has been fabricated using trilayer Nb-AlOx-Nb junctions. The SQUIDs are modulated with a common flux bias line and produce an output voltage swing of several millivolts across the array. The large output voltage will allow direct connection to room temperature electronics without the transformer coupling and resulting frequency limitations commonly associated with DC

R. P. Welty; J. M. Martinis

1991-01-01

74

Rf pumped SQUID with large output signal  

SciTech Connect

The dc SQUID had been presented for use in the rf SQUID instead of a weak link. The new device, referred to as double SQUID, possesses a large output signal (hundreds of microvolts) in operating in a hysteretic mode. For making an operating mode a double SQUID is coupled to a circuit traditional for rf SQUIDs containing a tank circuit and an rf current pumping generator. The magnetic flux being measured is recognized by the dc height of the flat part of the tank circuit I-V characteristics coupled to a double SQUID is modulated. It is this modulation that is the SQUID output signal. The experimental investigations of the double SQUID showed the validity of the assumptions under consideration. Output signals up to 690 {mu}V, noise spectral density {approx} 2 {times} 10{sup {minus}5} {phi}{sub 0}/Hz{sup 1/2} ({phi}{sub 0} is the flux quantum) and energy resolution {approx} 1.4 {times} 10{sup {minus}29}/Hz have been obtained.

Krivoy, G.S.; Komashko, V.A. (Omsk Polytechnical Inst., Mir Prospect 11, 644050 (SU))

1991-01-10

75

Mystery of the squid beak solved  

NSDL National Science Digital Library

A squid's mouth has a sharp beak that it uses to slice through the spinal cord of fish and tear them into pieces for an easy-to-eat meal. The squid beak is made out of some of the hardest material found in nature.

American Association for the Advancement of Science (AAAS;)

2008-03-27

76

SQUID magnetometers for low-frequency applications  

SciTech Connect

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

Ryhaenen, T.; Seppae, H. (Helsinki Univ. of Technology and Technical Research Centre of Finland, Espoo (Finland)); Ilmoniemi, R.; Knuutila, J. (Helsinki Univ. of Technology, Espoo (Finland))

1989-09-01

77

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 ...

78

SQUID Multiplexers for Cryogenic Detector Arrays  

NASA Technical Reports Server (NTRS)

SQUID multiplexers make it possible to build arrays of thousands of cryogenic detectors with a manageable number of readout channels. We are developing time-division SQUID multiplexers based on Nb trilayer SQUIDs to read arrays of superconducting transition-edge sensors. Our first-generation, 8-channel SQUID multiplexer was used in FIBRE, a one-dimensional TES array for submillimeter astronomy. Our second-generation 32-pixel multiplexer, based on an improved architecture, has been developed for instruments including Constellation-X, SCUBA-2, and solar x-ray astronomy missions. SCUBA-2, which is being developed for the James Clerk Maxwell Telescope, will have more than 10,000 pixels. We are now developing a third-generation architecture based on superconducting hot-electron switches. The use of SQUID multiplexers in instruments operating at above 2 K will also be discussed.

Irwin, Kent; Beall, James; Deiker, Steve; Doriese, Randy; Duncan, William; Hilton, Gene; Moseley, S. Harvey; Reintsema, Carl; Stahle, Caroline; Ullom, Joel; Vale, Leila

2004-01-01

79

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

80

Flying Cars  

NASA Technical Reports Server (NTRS)

Flying cars have nearly mythical appeal to nonpilots, a group that includes almost the whole human race. The appeal resides in the perceived utility of flying cars, vehicles that offer portal-to-portal transportation, yet break the bonds of road and traffic and travel freely through the sky at the drivers will. Part of the appeal is an assumption that flying cars can be as easy to fly as to drive. Flying cars have been part of the dream of aviation since the dawn of powered flight. Glenn Curtiss built, displayed, and maybe even flew a flying car in 1917, the Curtiss Autoplane. Many roadable airplanes were built in the 1930's, like the Waterman Arrowbile and the Fulton Airphibian. Two flying cars came close to production in the early 1950's. Ted Hall built a series of flying cars culminating in the Convaircar, sponsored by Consolidated Vultee, General Motors, and Hertz. Molt Taylor built and certified his Aerocar, and Ford came close to producing them. Three Aerocars are still flyable, two in museums in Seattle and Oshkosh, and the third owned and flown by Ed Sweeny. Flying cars do have problems, which so far have prevented commercial success. An obvious problem is complexity of the vehicle, the infrastructure, or both. Another is the difficulty of matching low power for normal driving with high power in flight. An automobile uses only about 20 hp at traffic speeds, while a personal airplane needs about 160 hp at speeds typical of flight. Many automobile engines can deliver 160 hp, but not for very long. A more subtle issue involves the drag of automobiles and airplanes. A good personal airplane can fly 30 miles per gallon of fuel at 200 mph. A good sports car would need 660 hp at the same speed and would travel only 3 miles per gallon. The difference is drag area, about 4.5 sq ft for the automobile and 1.4 sq ft for the airplane. A flying car better have the drag area of the airplane, not the car!

Crow, Steven

1996-01-01

81

Low field electron paramagnetic resonance imaging with SQUID detection  

NASA Technical Reports Server (NTRS)

In one embodiment, a flux transformer with a gradiometer pickup coil is magnetically coupled to a SQUID, and a SQUID array amplifier comprising a plurality of SQUIDs, connected in series, is magnetically coupled to the output of the SQUID. Other embodiments are described and claimed.

Hahn, Inseob (Inventor); Day, Peter K. (Inventor); Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Cohen, Mark S. (Inventor)

2012-01-01

82

A MINIATURE SQUID MAGNETOMETER FOR BIOMAGNETIC MEASUREMENTS WITH IMPROVED SELECTIVITY  

E-print Network

A MINIATURE SQUID MAGNETOMETER FOR BIOMAGNETIC MEASUREMENTS WITH IMPROVED SELECTIVITY J.A. Overweg a conventional gradiometer, so that a better flux transfer to the SQUID is possible. INTRODUCTION.- In most SQUID-magnetometer systems the external magnetic fields to be measured are coupled into the SQUID by a fluxtransformer

Paris-Sud XI, Université de

83

Squid Fishery in Texas: Biological, Economic, and Market Considerations  

E-print Network

Squid Fishery in Texas: Biological, Economic, and Market Considerations RAYMOND F. HIXON, ROGER T. HANLON, SAMUEL M. GILLESPIE, and WADE L. GRIFFIN Introduction Squids are considered to be one for squids have provided the impetus to reexamine the squid resources of the U.S. continental shelf. Most

84

Biological Considerations Relevant to the Management of Squid  

E-print Network

Biological Considerations Relevant to the Management of Squid (Loligo pealei and IIlex illecebrosus squid) and lllex illecebrosus (short-finned squid) are found in com- mercially exploited quantities aspects of the biology and population dynamics of these species relevant to the management of squid

85

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

86

Diffusion of Neon in White Dwarf Stars  

E-print Network

Sedimentation of the neutron rich isotope $^{22}$Ne may be an important source of gravitational energy during the cooling of white dwarf stars. This depends on the diffusion constant for $^{22}$Ne in strongly coupled plasma mixtures. We calculate self-diffusion constants $D_i$ from molecular dynamics simulations of carbon, oxygen, and neon mixtures. We find that $D_i$ in a mixture does not differ greatly from earlier one component plasma results. For strong coupling (coulomb parameter $\\Gamma>$ few), $D_i$ has a modest dependence on the charge $Z_i$ of the ion species, $D_i \\propto Z_i^{-2/3}$. However $D_i$ depends more strongly on $Z_i$ for weak coupling (smaller $\\Gamma$). We conclude that the self-diffusion constant $D_{\\rm Ne}$ for $^{22}$Ne in carbon, oxygen, and neon plasma mixtures is accurately known so that uncertainties in $D_{\\rm Ne}$ should be unimportant for simulations of white dwarf cooling.

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

2010-11-29

87

Trapped neon in ureilites: A new component  

NASA Astrophysics Data System (ADS)

Noble gases in five ureilites were analyzed by conventional noble gas mass spectrometry and, in one case, by closed-system combustion mass spectrometry of an acid-resistant residue. From analyses of the Hajmah ureilite a composition for trapped neon of Ne20/Ne22 = 10.4 +or- 0.3 is derived. This differs from all other known components of trapped neon. Its composition is compatible both with being fractionated solar Ne and being a mixture of solar Ne and Ne-E. The associated He has an He3/He4 ratio within the range of other trapped He compositions. Closed-system combustion data demonstrate the presence of an easily combustible fraction with low Ar36/Xe132 ratio, in accordance with the existence of a second gas component in addition to that residing in diamonds. Attempts to characterize this phase in the Nilpena ureilite reported to be diamond-free met with little success, because diamonds are present.

Ott, U.; Loehr, H. P.; Begemann, F.

88

Aperture effects in squid jet propulsion.  

PubMed

Squid are the largest jet propellers in nature as adults, but as paralarvae they are some of the smallest, faced with the inherent inefficiency of jet propulsion at a low Reynolds number. In this study we describe the behavior and kinematics of locomotion in 1 mm paralarvae of Dosidicus gigas, the smallest squid yet studied. They swim with hop-and-sink behavior and can engage in fast jets by reducing the size of the mantle aperture during the contraction phase of a jetting cycle. We go on to explore the general effects of a variable mantle and funnel aperture in a theoretical model of jet propulsion scaled from the smallest (1 mm mantle length) to the largest (3 m) squid. Aperture reduction during mantle contraction increases propulsive efficiency at all squid sizes, although 1 mm squid still suffer from low efficiency (20%) because of a limited speed of contraction. Efficiency increases to a peak of 40% for 1 cm squid, then slowly declines. Squid larger than 6 cm must either reduce contraction speed or increase aperture size to maintain stress within maximal muscle tolerance. Ecological pressure to maintain maximum velocity may lead them to increase aperture size, which reduces efficiency. This effect might be ameliorated by nonaxial flow during the refill phase of the cycle. Our model's predictions highlight areas for future empirical work, and emphasize the existence of complex behavioral options for maximizing efficiency at both very small and large sizes. PMID:24501132

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

2014-05-01

89

First demonstration of transcontinental SQUID magnetometry (Invited)  

NASA Astrophysics Data System (ADS)

We present the first simultaneous measurements from an ultra-sensitive dual-node transcontinental SQUID magnetometer network, available in real time on the internet. A three-axis low temperature SQUID sensor at LSBB Underground Research Laboratory, Rustrel, France (43.841 N, 5.484 E) and a two-axis high temperature SQUID sensor at SANSA Space Science in Hermanus, South Africa (34.424 S, 19.223 E), form the sensitive nodes of the network. Data are measured and GPS time stamped continuously at 125 Hz. The low-Tc SQUID at LSBB URL (known as a [SQUID]2 system) is inside a shielded steel capsule underneath 500 meters of karstic rock, which allows a low magnetic noise floor. The less sensitive high-Tc SQUID at SANSA Space Science is completely unshielded, and housed only in a magnetically neutral hut, 50 metres from a calibrated fluxgate node of the INTERMAGNET network, to protect it against the weather. The network, which is more sensitive than observatory fluxgate magnetometers, detects Earth's magnetosphere pulsations, Schumann waves, mesopause resonance, breathing modes of the Earth and oceanic swell. Our goal is further to extract directional or polarization information if earthquake precursors are observed again, as with the Sichuan-Wenchuan earthquake on 12 May 2008. In the medium term, we are exploring the possibility to extend the network with more spatially distributed SQUID sensors, such as at the South African National Antarctic Expedition's SANAE IV base in Antarctica.

Fourie, C.; Febvre, P.; Pozzo di Borgo, E.; Waysand, G.; Gouws, D.; Saunderson, E.; Henry, S.; Gaffet, S.; Janse van Vuuren, L.; Lochner, E. T.; Matladi, T.; Kwisanga, C.

2013-12-01

90

A 37 channel dc SQUID magnetometer system  

SciTech Connect

This paper reports on a 37 channel dc SQUID magnetometer system built for biomagnetic studies. The SQUID loop of each magnetometer serves as the active sensing element, thereby eliminating the need for flux coupling circuits. The magnetometers are located {approx equal}3 cm above the outer dewar bottom. The SQUIDs are directly coupled to a highly simplified read-out electronics using only 5 wires per channel; no helium temperature impedance matching circuits are required. Each channel can be independently inserted into or remove from the dewar.

Koch, H.; Cantor, R.; Drung, D.; Erne, S.N.; Matthies, K.P.; Peters, M.; Ryhanen, T.; Scheer, H.J.; Hahlbohn, H.D. (Physikalisch-Technische Bundesanstalt, Institut Berlin, Abbestr. 10-12, D-1000 Berlin (DE))

1991-03-01

91

1 MHz bandwidth true NMR SQUID amplifier  

SciTech Connect

We have developed an integrated dc SQUID magnetometer with additional positive feedback (APF) for low frequency true NMR applications. The APF scheme allows direct coupled read out from the SQUID to room temperature electronics and eliminates the need for the conventional modulation scheme, thereby greatly simplifying the flux-locked loop electronics. We have configured our SQUID system for the specific needs of sensitive NMR measurements which include large bandwidth and high slew rate. We have achieved a bandwidth of 1.2 MHz and a slew rate greater than 10{sup 5}{Phi}{sub 0}/s for frequencies above 10 kHz.

Thomasson, S.L.; Gould, C.M. [Univ. of Southern California, Los Angeles, CA (United States)

1995-10-01

92

The design and analysis of a DC SQUID for a SQUID microscope.  

E-print Network

??Thesis (MScEng (Electrical and Electronic Engineering)) – Stellenbosch University, 2008. This thesis relates to the analysis and design of a SQUID microscope. Superconductor theory is discussed… (more)

Burger, Willem Adriaan

2008-01-01

93

Measurement of Excitation Energy of Neon Prefragments  

NASA Astrophysics Data System (ADS)

Projectile fragmentation forms the basis for beam production at radioactive beam facilities such as the National Superconducting Cyclotron Laboratory (NSCL), yet uncertainties remain about the specifics of the production mechanism. For example, very little is known about the excitation energy of the precursors of the observed final fragments. In the present work, neon isotopes produced in the fragmentation of a ^32Mg beam at 86 MeV/nucleon on a Beryllium target, ranging in mass loss from ?A = 3-10, were observed and the coincident neutrons were detected using the Modular Neutron Array (MoNA). A strong correlation between the neutron multiplicities and fragmentation mass loss was observed, and the variation compares well to that from a statistical evaporation model.

Mosby, M.; Morrissey, D. J.; Thoennessen, M.

2011-10-01

94

76 FR 68642 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Amendment 11 AGENCY: National...the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan, developed...longfin squid, Illex squid, and butterfish; and the establishment of a...

2011-11-07

95

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

96

Reproducible step-edge junction SQUIDs  

Microsoft Academic Search

High-Tc superconducting YBCO SQUIDs have been developed based on step-edge junctions. The step-edges were fabricated by using electron-beam lithography and Ar-ion milling on SrTiO3 substrates. The V(?) peak-to-peak voltage is around 10 ?V, and the IcRn product is 150 ?V at 77 K. The SQUIDs prepared on the same substrate show reproducible parameters within 30%. At 77 K the noise

Y. Q. Shen; Z. J. Sun; R. Kromann; T. Holst; P. Vase; T. Freltoft

1995-01-01

97

Amino acid sequence of squid troponin C  

Microsoft Academic Search

The complete amino acid sequence of squid Todarodes pacificus troponin C (TnC), which was shown to bind only 1 mol Ca2+\\/mol, was determined by both the Edman and cDNA methods. The squid TnC is composed of 147 amino acids including an unblocked Pro at the N-terminus and the calculated molecular weight is 17003.9. Among the four potential Ca2+-binding sites, namely

Takao Ojima; Tomokatsu Ohta; Kiyoyoshi Nishita

2001-01-01

98

Binge flying  

Microsoft Academic Search

Recent popular press suggests that ‘binge flying’ constitutes a new site of behavioural addiction. We theoretically appraise and empirically support this proposition through interviews with consumers in Norway and the United Kingdom conducted in 2009. Consistent findings from across two national contexts evidence a growing negative discourse towards frequent short-haul tourist air travel and illustrate strategies of guilt suppression and

James E. S. Higham; Christina T. Cavaliere

2011-01-01

99

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

100

Acceleration of neon pellets to high speeds for fusion applications  

NASA Astrophysics Data System (ADS)

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 ˜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.

Combs, S. K.; Love, T. L.; Jernigan, T. C.; Milora, S. L.; Frattolillo, A.; Migliori, S.

1996-03-01

101

Interactive Fly  

NSDL National Science Digital Library

This site is award-winning and comprehensive. It thoroughly discusses genes, tissues, biochemical paths, and developmental processes in the fruit fly, Drosophila. Its gene index identifies genes with their functions, maternal and zygotically transcribed genes, genes important to behavior and genes in conserved pathways. Its tissue and organ development section shows stages and an atlas, as well as genes and processes in gastrulation, histogenesis, morphogenesis, organogenesis, imaginal discs, adult formation, oogenesis and spermatogenesis.

PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

2005-09-13

102

ICP and the Squid Web Cache \\Lambda Duane Wessels  

E-print Network

ICP and the Squid Web Cache \\Lambda Duane Wessels k claffy August 13, 1997 Abstract We describe the structure and functionality of the Internet Cache Protocol (ICP) and its implementation in the Squid Web

California at San Diego, University of

103

Boundary Field Theory Approach to the Renormalization of SQUID Devices  

E-print Network

We show that the quantum properties of some Josephson SQUID devices are described by a boundary sine Gordon model. Our approach naturally describes multi-junction SQUID devices and, when applied to a single junction SQUID (the rf-SQUID), it reproduces the known results of Glazman and Hekking. We provide a detailed analysis of the regimes accessible to an rf-SQUID and to a two-Josephson junction SQUID device (the dc-SQUID). We then compute the normal component of the current-response of a SQUID device to an externally applied voltage and show that the equation describing the current-voltage characteristic function reduces to well-known results when the infrared cutoff is suitably chosen. Our approach helps in establishing new and interesting connections between superconducting devices, quantum brownian motion, fermionic quantum wires and, more generally, quantum impurity problems.

Domenico Giuliano; Pasquale Sodano

2006-08-27

104

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

105

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

106

The effects of radio frequency radiation on the dc SQUID  

SciTech Connect

The effects of radio frequency radiation on the dc SQUID are examined. Simulations show how the shape of the SQUID transfer characteristic is distorted by radio frequency interference (RFI). How this affects three commonly used SQUID modulation methods is discussed, and the results explain why the authors experimentally observe the bias current reversing readout method to be the least susceptible to RFI. The commonly seen increase in the low frequency flux noise power spectrum of dc SQUIDs in unshielded environments is also explained.

Koch, R.H.; Foglietti, V.; Rozen, J.R.; Stawiasz, K.G.; Ketchen, M.B.; Lathrop, D.K.; Sun, J.Z.; Gallagher, W.J. [IBM Thomas J. Watson Research Center, Yorktown Heights, NY (United States)

1994-12-31

107

DC-SQUID electronics based on adaptive positive feedback; Experiments  

SciTech Connect

This paper demonstrates that the dc-SQUID read-out electronics can be realized utilizing positive feedback without deteriorating the SQUID noise performance. The required gain rise is achieved by interconnecting the SQUID output and a flux modulation coil via a cooled FET acting as a voltage-controlled resistor, different SQUIDs with different types of FETs have been studied experimentally. Possibilities to build an adaptive control of the feedback gain produced by the positive feedback are briefly discussed.

Seppa, H. (Metrology Research Inst., VTT, Technical Research Centre of Finland, Otakaari 7B, SF-02150 Espoo (FI)); Ahonen, A.; Knuutila, J.; Simola, J.; Vilkman, V. (Low Temperature Lab., Helsinki Univ. of Technology, SF-02150 Espoo (FI))

1991-03-01

108

ORIGINAL RESEARCH Genetic determinants of swimming motility in the squid  

E-print Network

ORIGINAL RESEARCH Genetic determinants of swimming motility in the squid light-organ symbiont for the colo- nization of the light-emitting organ of the Hawaiian bobtail squid, Euprymna scolopes are able to colonize a subset of juvenile squid to light-producing levels. Thirty-three genes required

McFall-Ngai, Margaret

109

Low Field dc SQUID NMR on Room Temperature Samples  

E-print Network

Low Field dc SQUID NMR on Room Temperature Samples and Single Crystal UPt3 by Aya Shibahara is the technique of dc SQUID NMR. Firstly the application of the technique for broadband spectroscopy on room temperature samples is described. The mo- tivation behind this work was to try to obtain SQUID NMR signals

Sheldon, Nathan D.

110

The Foreign Squid Fishery Off the Northeast United States Coast  

E-print Network

The Foreign Squid Fishery Off the Northeast United States Coast DAVID J. KOLATOR and DOUGLAS P LONG Introduction Squid has long been a popular food fish in the foreign market and thus a highly sought marine resource by the foreign fishing fleet. Foreign vessels began reporting incidental catches of squid off

111

INTRODUCTION Squid employ a complex locomotive approach involving two  

E-print Network

2009 INTRODUCTION Squid employ a complex locomotive approach involving two separate systems, the pulsed jet and movement of the lateral fins (Bartol et al., 2001b). However, many studies involving squid of squid may play important roles in lift and thrust production at various speeds. In fact, based on force

Stewart, William J.

112

Information Panel The Embryonic Development of the Hawaiian Bobtail Squid  

E-print Network

Information Panel The Embryonic Development of the Hawaiian Bobtail Squid (Euprymna scolopes the growing interest in Hawaiian bobtail squid (Euprymna scolopes) as a contemporary cephalopod developmental, and potential uses of E. scolopes as model organisms, see The Hawaiian Bobtail Squid (Euprymna scolopes

McFall-Ngai, Margaret

113

Evolution of graded refractive index in squid lenses  

E-print Network

Evolution of graded refractive index in squid lenses Alison M. Sweeney1,*, David L. Des Marais1 be minimized. Squid lens S-crystallin proteins are evolution- arily derived from the glutathione S underlying the production and maintenance of camera-like optics in squid lenses. Keywords: graded refractive

Johnsen, Sönke

114

Many loliginid squid populations depend entirely upon the reproduc-  

E-print Network

306 Many loliginid squid populations depend entirely upon the reproduc- tive output- mens, 2000; Semmens and Moltschani- wskyj, 2000). In California waters, Loligo opalescens (market squid, also known as the opalescent inshore squid [FAO]) live only 6-12 months (Butler et al., 1999) and die

115

SQUID MEASUREMENTS OF MAGNETIC VORTICES IN VERY UNDERDOPED  

E-print Network

SQUID MEASUREMENTS OF MAGNETIC VORTICES IN VERY UNDERDOPED YTTRIUM Superconducting QUantum Interference Device (SQUID) susceptometer ­ a new tool for the study of local magnetic in the cuprate superconductor YBa2Cu3O6+x . These studies demonstrate that the scanning SQUID susceptometer can

Moler, Kathryn A.

116

"SQUID Susceptometry Imaging of Magnetic Nanoparticles" Solomon Diamond  

E-print Network

"SQUID Susceptometry Imaging of Magnetic Nanoparticles" Solomon Diamond 2010-2011 We have completed for synchronized recording of the SQUID system, encoder, and a fluxgate magnetometer and also developed software for magnetic field simulation and data analysis. We have demonstrated experimentally that the SQUID system can

Shepherd, Simon

117

NANO-SQUID SUSCEPTOMETRY AND FLUCTUATION EFFECTS IN SUPERCONDUCTING RINGS  

E-print Network

NANO-SQUID SUSCEPTOMETRY AND FLUCTUATION EFFECTS IN SUPERCONDUCTING RINGS A DISSERTATION SUBMITTED of two generations of Scanning Superconducting Quantum Interference Device (SQUID) sensors, and the use to taking images of the magnetic field. The second chapter describes a generation of SQUIDs with FIB

Moler, Kathryn A.

118

Orientation dependence of broadband acoustic backscattering from live squid  

E-print Network

Orientation dependence of broadband acoustic backscattering from live squid Wu-Jung Lee, Andone C squid (Loligo pealeii) was conducted using linear chirp signals (60­103 kHz) with data collected over with an analytical prolate spheroid model and a three-dimensional numerical model with randomized squid shape, both

Stanton, Tim

119

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

120

Scanning SQUID microscope differentiation of ferromagnetic steelphases  

SciTech Connect

We have studies the remanent magnetization of ferromagneticsteel with five different microstructures using a microscope based on ahigh-transition-temperature dc Superconducting QUantum InterferenceDevice (SQUID). We prepared the samples using different heat treatments,beginning with the same material composition. We magnetized each samplein turn in a magnetic field of 50 mT, and studied the remanentmagnetization by scanning the sample over the SQUID using atwo-dimensional (2D) translation stage with a range of 50 mm X 50 mm.With a sample-to-SQUID separation of 400-500(mu)m, this procedure yieldeda 2D magnetic field image produced by the local remanent magnetization ofthe sample. In addition, we have obtained microstructural informationusing optical imaging, allowing us to correlate the magnetic images withthe underlying microstructure.

Shaw, T.J.; Chan, J.W.; Kang, S.-H.; McDermott, R.; Morris Jr.,J.W.; Clarke, John

1999-09-01

121

Power gain of a SQUID amplifier  

NASA Astrophysics Data System (ADS)

The power gain of a dc superconducting quantum interference device (SQUID) amplifier, with tuned input and output circuits, is computed as a function of the current and magnetic biases. A gain of 20300 is found at 1.5 GHz and 3470 at 3.0 GHz, implying a frequency dependence to the gain of approximately 1/omega-squared. The gain, as derived from the resistively shunted junction model, is compared with the gain of a simplified model based on the dc magnetic response V(phi). This comparison shows that the V(phi) description of the SQUID can lead to large errors.

McDonald, D. G.

1984-03-01

122

Impedance Magnetocardiography using High-Tc SQUIDs  

NASA Astrophysics Data System (ADS)

We report on Impedance Magnetocardiography (IMCG) measurements using High-Tc SQUID magnetometers in an unshielded environment. A low amplitude high frequency ac current is passed through the body through outer electrodes. Variations in blood flow during the cardiac cycle generate currents that give rise to time varying magnetic fields. Potential applications related to blood flow include imaging of blood perfusion in the myocardium, the detection of pulmonary embolisms (PE's), and studies of the effects of anticoagulants on PE's. An electromagnetic model is used to predict the SQUID response to changes in tissue conductivity and blood volume during the cardiac cycle.

Vajrala, V.; Nawarathna, D.; Claycomb, J. R.; Prodan Miller, C., Jr.

2003-03-01

123

Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package.  

PubMed

Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed 'flashing' is characterized by a global oscillation (2-4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed 'flickering' was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species. PMID:25609785

Rosen, Hannah; Gilly, William; Bell, Lauren; Abernathy, Kyler; Marshall, Greg

2015-01-15

124

Design of a hysteretic SQUID as the readout for a dc SQUID  

SciTech Connect

This paper present a design for an optimal hysteretic SQUID readout circuit for a DC SQUID, thus eliminating the need for bulky output transformers or resonance matching circuits. The hysteretic readout system, which is based in part on standard sampling theory, is compared to another similar system and shown to be superior in terms of slew rate and immunity of electromagnetic interference. The circuit will be useful in optimizing the performance of biomagnetic systems.

Gershenson, M. (Naval Coastal Systems Center, Panama City, FL (United States))

1991-03-01

125

Hydrogen bonding between neon and hydrogen fluoride M. Losonczy and J. W. Moskowitz*  

E-print Network

-neon and for hydrogen fluoride-neon linear hydrogen bonds will be borne out by later more extensive calculations. IIHydrogen bonding between neon and hydrogen fluoride M. Losonczy and J. W. Moskowitz* Chemistry Department, New York University, Washington Square College, New York, New York JOOO3 F. H. Stillinger Bell

Stillinger, Frank

126

Fly ash and fly ash concrete  

Microsoft Academic Search

Fly ash is a residue that results from the combustion of ground or powdered coal. Historically, fly ash has been referred to as a pozzolan and is used to reduce the amount of portland cement in concrete. However, in many Western States fly ashes have cementitious properties as well as pozzolanic properties, and they are capable of producing good strengths

Dunstan; E. R. Jr

1984-01-01

127

Fast imaging of intact and shattered cryogenic neon pellets  

NASA Astrophysics Data System (ADS)

Compact condensed-matter injection technologies are increasingly used in magnetic fusion. One recent application is in disruption mitigation. An imaging system with less-than-100-µm- and sub-µs-resolution is described and used to characterize intact and shattered cryogenic neon pellets. Shattered pellets contain fine particles ranging from tens of µm to about 7 mm. Time-of-flight analyses indicate that pellets could slow down if hitting the wall of the guide tube. Fast high-resolution imaging systems are thus useful to neon and other condensed-matter injector development.

Wang, Zhehui; Combs, S. K.; Baylor, L. R.; Foust, C. R.; Lyttle, M. S.; Meitner, S. J.; Rasmussen, D. A.

2014-11-01

128

Fast imaging of intact and shattered cryogenic neon pellets.  

PubMed

Compact condensed-matter injection technologies are increasingly used in magnetic fusion. One recent application is in disruption mitigation. An imaging system with less-than-100-µm- and sub-µs-resolution is described and used to characterize intact and shattered cryogenic neon pellets. Shattered pellets contain fine particles ranging from tens of µm to about 7 mm. Time-of-flight analyses indicate that pellets could slow down if hitting the wall of the guide tube. Fast high-resolution imaging systems are thus useful to neon and other condensed-matter injector development. PMID:25430370

Wang, Zhehui; Combs, S K; Baylor, L R; Foust, C R; Lyttle, M S; Meitner, S J; Rasmussen, D A

2014-11-01

129

Diffuse ?-mode atmospheric pressure radio-frequency discharge in neon  

NASA Astrophysics Data System (ADS)

In this work, a radio-frequency (RF) atmospheric pressure glow discharge burning in neon between planar metal electrodes is achieved for the first time. The RF discharge can operate in two stable modes: in a diffuse ?-mode with uniformly covered electrode surfaces and in a constricted ?-mode. Similarities are revealed when the discharge is compared against the RF atmospheric pressure glow discharge in helium, namely both discharges show a discontinuity and a hysteresis in the current-voltage characteristic at the mode transition; the spatio-temporal profiles of the light emission in the ?-mode from neon, helium and atomic oxygen are also similar.

Navrátil, Z.; Dosoudilová, L.; Josepson, R.; Dvo?ák, P.; Trunec, D.

2014-08-01

130

Fast Imaging of Intact and Shattered Cryogenic Neon Pellets  

SciTech Connect

Compact condensed-matter injection technologies are increasingly used in magnetic fusion. One recent application is in disruption mitigation. An imaging system with less-than-100- m- and sub- s-resolution is described and used to characterize intact and shattered cryogenic neon pellets. Shattered pellets contain fine particles ranging from tens of m to about 7 mm. Time-of-flight analyses indicate that pellets could slow down if hitting the wall of the guide tube. Fast high-resolution imaging systems are thus useful to neon and other condensed-matter injector development.

Wang, Zhehui [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Combs, Stephen Kirk [ORNL] [ORNL; Baylor, Larry R [ORNL] [ORNL; Foust, Charles R [ORNL] [ORNL; Lyttle, Mark S [ORNL] [ORNL; Meitner, Steven J [ORNL] [ORNL; Rasmussen, David A [ORNL] [ORNL

2014-01-01

131

Boiling incipience and convective boiling of neon and nitrogen  

NASA Technical Reports Server (NTRS)

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 and convective boiling heat transfer coefficients in uniformly heated flow channels. The accuracy of the correlating equations was then evaluated. A technique was also developed to calculate the position of boiling incipience in a uniformly heated flow channel. Comparisons made with the experimental data showed a prediction accuracy of + or - 15 percent.

Papell, S. S.; Hendricks, R. C.

1977-01-01

132

SQUID Amplifier System for Vibrating Wire Resonators  

Microsoft Academic Search

We describe a simple coupling scheme of superconducting vibrating wire resonators to a SQUID amplifier for achieving supreme signal to noise characteristics. Our construction resulted in a gain factor near 108?0\\/V at 1kHz with an amplifier noise level of about 20 ??0\\/\\u000a

J. Martikainen; J. T. Tuoriniemi

2001-01-01

133

Sodium Extrusion by Internally Dialyzed Squid Axons  

Microsoft Academic Search

A method has been developed which allows a length of elec- trically excitable squid axon to be internally dialyzed against a continuously flowing solution of defined composition. Tests showed that diffusional exchange of small molecules in the axoplasm surrounding the dialysis tube occurred with a half-time of 2-5 rain, and that protein does not cross the wall of the dialysis

F. J. Brinley; L. J. MULLINS

1967-01-01

134

Monolithic 77 K dc SQUID magnetometer  

SciTech Connect

We report the first fabrication of a monolithic dc SQUID magnetometer that operates above 77 K. We have used bi-epitaxial grain boundary Josephson junctions in YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) to produce the SQUID itself while the flux transformer consists of heteroepitaxial layers of YBCO/SrTiO{sub 3}/LaAlO{sub 3}/SrTiO{sub 3}/YBCO. In the circuit fabricated, the SQUID is built on top of the epitaxial layers of the flux transformer. We have used dry etching, ion-beam cleaning, and photolithographic processing to pattern all the layers. Via contacts and step coverage of the epitaxial wire layers have been achieved without significant degradation of the superconducting properties of any of the three YBCO layers. The magnetometer enhances the magnetic field sensitivity of the bare SQUID by a factor of 127, giving an effective area, {ital d}{Phi}/{ital dB}, of 1.9 mm{sup 2}.

Lee, L.P.; Char, K.; Colclough, M.S.; Zaharchuk, G. (Conductus, Inc., Sunnyvale, California (USA))

1991-12-02

135

ICP and the Squid Web Cache  

Microsoft Academic Search

We describe the structure and functionality of the Internet Cache Protocol (ICP) and itsimplementation in the Squid Web Caching software. ICP is a lightweight message format usedfor communication among Web caches. Caches exchange ICP queries and replies to gatherinformation to use in selecting the most appropriate location from which to retrieve an object.We present background on the history of ICP,

Duane Wessels

1997-01-01

136

One Period of Exploration with the Squid.  

ERIC Educational Resources Information Center

Presents a lab that can be offered after students have learned the basic anatomy and physiology of the various phyla, the primary objective of which is to explore and apply their acquired knowledge to a new situation. Involves exploring the anatomy and life-style of the squid. (JRH)

Bradley, James V.; Ng, Andrew

1997-01-01

137

ICP and the Squid web cache  

Microsoft Academic Search

We describe the structure and functionality of the Internet cache protocol (ICP) and its implementation in the Squid web caching software. ICP is a lightweight message format used for communication among Web caches. Caches exchange ICP queries and replies to gather information to use in selecting the most appropriate location from which to retrieve an object. We present background on

Duane Wessels; K. Claffy

1998-01-01

138

Squid Dissection: From Pen to Ink.  

ERIC Educational Resources Information Center

Introduces students to dissection, which is an important part of scientific discovery. Students not only gain an understanding of the anatomy of a squid, but also develop a sense of responsibility and respect for the animal that they are using as a learning tool. (Author/SOE)

Brown, Cindy; Kisiel, Jim

2003-01-01

139

Patch voltage clamp of squid axon membrane  

Microsoft Academic Search

Summary A small area (patch) of the external surface of a squid axon can be “isolated” electrically from the surrounding bath by means of a pair of concentric glass pipettes. The seawater-filled inner pipette makes contact with the axon and constitutes the external access to the patch. The outer pipette is used to direct flowing sucrose solution over the area

Harvey M. Fishman

1975-01-01

140

Bioelectronics: A positive future for squid proteins  

NASA Astrophysics Data System (ADS)

Protein-based protonic conductivity plays an important role in nature, but has been explored little outside of a biological setting. Now, proton conductors have been developed based on the squid protein reflectin, and integrated with devices for potential bioelectronic applications.

Rolandi, Marco

2014-07-01

141

High-gain weakly nonlinear flux-modulated Josephson parametric amplifier using a SQUID-array  

E-print Network

High-gain weakly nonlinear flux-modulated Josephson parametric amplifier using a SQUID-array X devices (SQUIDs). This amplifier is parametrically pumped by modulating the flux threading the SQUIDs be obtained with a single SQUID of the same inductance, due to the smaller nonlinearity of the SQUID array. 1

Boyer, Edmond

142

Choreography of the squid's "nuptial dance".  

PubMed

A mass spawning of squid resembles, at first glance, a chaotic "nuptial dance" (1). But for the first time, we have applied 3-D, radio-linked acoustic positioning (RAP) to this confusing process, and our early results now reveal a choreography that is, in fact, well organized in time and space. Remote tracking with RAP of individual Loligo vulgaris reynaudii off South Africa has provided insights into the daily sequence of behaviours that lead these animals to aggregate for sexual selection. Each dawn, the squid navigate for several kilometers, towards the shore, to small, well-defined zones near egg beds on the substrate. After several hours of circling above the egg beds, a pelagic, 3-D lek-like aggregation of large males forms: females are drawn in, and the aggregation condenses as the females and males pair, mate, and lay eggs. Smaller "sneaker males" remain on the periphery of the mating arena and, from this station, attempt extra-pair copulations (EPCs). The mating system of squids is thus unexpectedly complex, rivaling those of mammals and birds (2, 3). Commercial squid-jigging fishermen in South Africa have recently been attracted to the spawning grounds, and they have been successful. Moreover, their activities may be selective for large males. Thus, attention should be devoted to ensuring that such targeted fishing does not alter the characteristics of squid population genetics. Remote tracking and video observations, in combination with genetic analyses, may offer a new opportunity to monitor mating effort and reproductive success, and thus to manage the fishery. PMID:9145496

Sauer, W H; Roberts, M J; Lipinski, M R; Smale, M J; Hanlon, R T; Webber, D M; O'Dor, R K

1997-04-01

143

Fly on the Ceiling  

NSDL National Science Digital Library

In this math lesson, learners play two different games to help them understand coordinates. First, learners read the book, "The Fly on the Ceiling," by Julie Glass. Then, learners play "Fly Tic-Tac-Toe," a game similar to tic-tac-toe but with coordinates, and "Swat the Flies," a game similar to Battleship but with flies. Each game requires two players.

Lessonplans, Utah

2012-10-30

144

Moderately shielded high-Tc SQUID system for rat MCG  

NASA Astrophysics Data System (ADS)

Recently, we have developed a 5-channel high-Tc SQUID system with one signal channel intended for rat magnetocardiography (MCG) in moderately shielded or "quiet" real environment. This system is an adapted version of a human MCG system which has been improved with respect to user-friendliness and stability. A dewar with a cold-warm distance of 7 mm and a refill cycle time of up to one week is utilized. The implemented high-Tc SQUIDs are single-layer devices with grain boundary junctions fabricated at KRISS with laser ablation on 10 mm × 10 mm STO substrates. In order to cancel environmental magnetic noise, three of the five SQUIDs are arranged to build an axial software first-order or second-order gradiometer with a base line of 35 mm. The other two SQUIDs are used for balancing. To overcome previous system instabilities, we have implemented an Earth field compensation for each SQUID. For this, the SQUIDs were mounted in capsules containing integrated field compensation coils. The three Earth field components are measured with an additional triaxial fluxgate, and compensated at the SQUID locations using the low-noise current source of the SQUID readout electronics. This way, the SQUIDs can be cooled and operated in a low residual field that improves system stability and reduces low-frequency SQUID noise. It is even possible to slowly move the dewar in the Earth field (dynamic field compensation). Different noise cancellation procedures were optimized and compared employing a periodic signal source.

Bechstein, S.; Kim, I.-S.; Drung, D.; Novikov, I.; Schurig, Th

2010-06-01

145

SIMPLODE: An imploding gas puff plasma model. 1. Neon  

NASA Astrophysics Data System (ADS)

A non-LTE dynamic pinch model - SIMPLODE - has been developed and applied to describing the implosion dynamics of a K-shell radiating gas puff. Numerical simulations have been carried out with neon gas puffs and compared with recent experimental results obtained on GAMBLE II. In addition, the influence of the Plasma Erosion Opening Switch on the K-shell yield is investigated.

Davis, J.; Agritellis, C.; Duston, D.

1985-07-01

146

Cosmogenic neon from precompaction irradiation of Kapoeta and Murchison  

NASA Technical Reports Server (NTRS)

Neon from hand-picked Murchison and Kapoeta grains, selected on the basis of the presence or absence of solar flare particle tracks, was analyzed in order to delineate the precompaction history of this material. The irradiated grains showed large enrichments of cosmogenic neon relative to the unirradiated grains. Galactic cosmic ray (GCR) exposure ages for the unirradiated grains yield the nominal values reported for the recent exposure history of these meteorites. Apparent minimum precompaction galactic exposure ages of 28 m.y. and 56 m.y. would have been obtained for Murchison and Kapoeta, respectively, if the cosmogenic effects in the irradiated grains were due to GCR irradiation. Since this seems unreasonably long, the cosmogenic neon in the irradiated grains may be due to spallation by solar cosmic rays. This, however, would require a more active early sun. The isotopic composition of the cosmogenic neon in these grains suggests a harder energy spectrum than is characteristic of present solar flares. Lack of apparent solar wind effects may require some kind of shielding, such as nebular gas.

Caffee, M. W.; Hohenberg, C. M.; Swindle, T. D.; Goswami, J. N.

1983-01-01

147

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

148

78 FR 46903 - Control Date for Qualifying Landings History and to Limit Speculative Entry into the Illex Squid...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Fishery; Atlantic Mackerel, Squid and Butterfish Fishery Management Plan AGENCY: National...The Atlantic Mackerel, Squid, and Butterfish (MSB) Fishery Management Plan (FMP...the Illex squid, longfin squid, and butterfish fisheries, subject to Federal...

2013-08-02

149

Jet flow in steadily swimming adult squid.  

PubMed

Although various hydrodynamic models have been used in past analyses of squid jet propulsion, no previous investigations have definitively determined the fluid structure of the jets of steadily swimming squid. In addition, few accurate measurements of jet velocity and other jet parameters in squid have been reported. We used digital particle imaging velocimetry (DPIV) to visualize the jet flow of adult long-finned squid Loligo pealei (mantle length, L(m)=27.1+/-3.0 cm, mean +/-S.D.) swimming in a flume over a wide range of speeds (10.1-59.3 cm s(-1), i.e. 0.33-2.06 L(m) s(-1)). Qualitatively, squid jets were periodic, steady, and prolonged emissions of fluid that exhibited an elongated core of high speed flow. The development of a leading vortex ring common to jets emitted from pipes into still water often appeared to be diminished and delayed. We were able to mimic this effect in jets produced by a piston and pipe arrangement aligned with a uniform background flow. As in continuous jets, squid jets showed evidence of the growth of instability waves in the jet shear layer followed by the breakup of the jet into packets of vorticity of varying degrees of coherence. These ranged from apparent chains of short-lived vortex rings to turbulent plumes. There was some evidence of the complete roll-up of a handful of shorter jets into single vortex rings, but steady propulsion by individual vortex ring puffs was never observed. Quantitatively, the length of the jet structure in the visualized field of view, L(j), was observed to be 7.2-25.6 cm, and jet plug lengths, L, were estimated to be 4.4-49.4 cm using average jet velocity and jet period. These lengths and an average jet orifice diameter, D, of 0.8 cm were used to calculate the ratios L(j)/D and L/D, which ranged from 9.0 to 32.0 and 5.5 to 61.8, respectively. Jets emitted from pipes in the presence of a background flow suggested that the ratio between the background flow velocity and the jet velocity was more important than L/D to predict jet structure. Average jet velocities in steadily swimming squid ranged from 19.9 to 85.8 cm s(-1) (0.90-2.98 L(m) s(-1)) and were always greater in magnitude than swimming speed. Maximum instantaneous fluid speeds within squid jets ranged from 25.6 to 136.4 cm s(-1). Average jet thrust determined both from jet velocity and from three-dimensional approximations of momentum change in successive jet visualizations showed some differences and ranged from 0.009 to 0.045 N over the range of swimming speeds observed. The fraction by which the average jet velocity exceeded the swimming speed, or 'slip', decreased with increasing swimming speed, which reveals higher jet propulsive efficiency at higher swimming speeds. Jet angle, subtended from the horizontal, decreased from approximately 29 degrees to 7 degrees with increasing swimming speed. Jet frequency ranged from 0.6 to 1.3 Hz in the majority of swimming sequences, and the data suggest higher frequencies at the lowest and highest speeds. Jet velocity, angle, period and frequency exhibited increased variability at speeds between 0.6 and 1.4 L(m) s(-1). This suggests that at medium speeds squid enjoy an increased flexibility in the locomotive strategies they use to control their dynamic balance. PMID:15767313

Anderson, Erik J; Grosenbaugh, Mark A

2005-03-01

150

Virtual fly  

NSDL National Science Digital Library

3D virtual image of a blow fly (Family Calliphoridae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

151

75 FR 70187 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Specifications and Management...for Atlantic mackerel, squid, and butterfish (MSB). This action proposes to modify...with no TALFF specified for squid. For butterfish, the regulations specify that a...

2010-11-17

152

78 FR 14230 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 7 AGENCY...SUMMARY: NMFS is changing the butterfish mortality cap on the longfin squid fishery...the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan. This...

2013-03-05

153

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Control Date for Loligo and Illex Squid AGENCY...proposed rulemaking for the Atlantic mackerel, squid, and butterfish (MSB) fisheries. This rulemaking could institute...

2010-01-08

154

50 CFR 648.25 - Atlantic Mackerel, squid, and butterfish framework adjustments to management measures.  

Code of Federal Regulations, 2012 CFR

...false Atlantic Mackerel, squid, and butterfish framework adjustments to management...the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.25 Atlantic Mackerel, squid, and butterfish framework adjustments to...

2012-10-01

155

50 CFR 648.27 - Observer requirements for the longfin squid fishery.  

Code of Federal Regulations, 2013 CFR

...for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.27 Observer requirements...A vessel issued a longfin squid and butterfish moratorium permit, as specified...A vessel issued a longfin squid and butterfish moratorium permit, as specified...

2013-10-01

156

75 FR 37739 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Adjustment to the Loligo...the Atlantic Mackerel, Squid, and Butterfish Fisheries Management Plan, which modified...the Atlantic Mackerel, Squid, and Butterfish Fisheries in the Federal Register...

2010-06-30

157

50 CFR 648.22 - Atlantic mackerel, squid, and butterfish specifications.  

Code of Federal Regulations, 2012 CFR

...false Atlantic mackerel, squid, and butterfish specifications. 648.22 Section...the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.22 Atlantic mackerel, squid, and butterfish specifications. (a) Initial...

2012-10-01

158

77 FR 58507 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 5 AGENCY...the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan (MSB FMP...the Atlantic Mackerel, Squid, and Butterfish FMP, other provision of the...

2012-09-21

159

50 CFR 648.27 - Observer requirements for the longfin squid fishery.  

Code of Federal Regulations, 2012 CFR

...for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.27 Observer requirements...A vessel issued a longfin squid and butterfish moratorium permit, as specified...A vessel issued a longfin squid and butterfish moratorium permit, as specified...

2012-10-01

160

50 CFR 648.26 - Mackerel, squid, and butterfish possession restrictions.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Mackerel, squid, and butterfish possession restrictions. 648.26...for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.26 Mackerel, squid, and butterfish possession restrictions. (a)...

2013-10-01

161

50 CFR 648.25 - Atlantic Mackerel, squid, and butterfish framework adjustments to management measures.  

Code of Federal Regulations, 2013 CFR

...false Atlantic Mackerel, squid, and butterfish framework adjustments to management...the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.25 Atlantic Mackerel, squid, and butterfish framework adjustments to...

2013-10-01

162

77 FR 7544 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Amendment 11; Correction...the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan. DATES: Effective...the Atlantic Mackerel, Squid, and Butterfish (MSB) Fishery Management Plan...

2012-02-13

163

50 CFR 648.26 - Mackerel, squid, and butterfish possession restrictions.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Mackerel, squid, and butterfish possession restrictions. 648.26...for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.26 Mackerel, squid, and butterfish possession restrictions. (a)...

2012-10-01

164

78 FR 3346 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Specifications and Management...mackerel, and 2013 specifications for butterfish. Specifications for longfin squid and...changes to the longfin squid fishery, the butterfish mortality cap to avoid 1-2 week...

2013-01-16

165

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

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 7 AGENCY...SUMMARY: NMFS proposes changing the butterfish mortality cap on the longfin squid fishery...the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan,. This...

2012-12-13

166

76 FR 8306 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Specifications and Management...the Atlantic mackerel, squid, and butterfish (MSB) fisheries. Specifically, this...with no TALFF specified for squid. For butterfish, the regulations specify that a...

2011-02-14

167

77 FR 69426 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Specifications and Management...mackerel, and 2013 specifications for butterfish. Specifications for longfin squid and...longfin squid fishery, as well as the butterfish mortality cap to avoid 1-2 week...

2012-11-19

168

Coupled Serial and Parallel Non-uniform SQUIDs  

SciTech Connect

In this work we numerical model series and parallel non-uniform superconducting quantum interference device (SQUID) array. Previous work has shown that series SQUID array constructed with a random distribution of loop sizes, (i.e. different areas for each SQUID loop) there exists a unique 'anti-peak' at the zero magnetic field for the voltage versus applied magnetic field (V-B). Similar results extend to a parallel SQUID array where the difference lies in the arrangement of the Josephson junctions. Other system parameter such as bias current, the number of loops, and mutual inductances are varied to demonstrate the change in dynamic range and linearity of the V-B response. Application of the SQUID array as a low noise amplifier (LNA) would increase link margins and affect the entire communication system. For unmanned aerial vehicles (UAVs), size, weight and power are limited, the SQUID array would allow use of practical 'electrically small' antennas that provide acceptable gain.

Longhini, Patrick; In, Visarath [Space and Naval Warfare Systems Center, 53560 Hull Street, San Diego, CA 92152-5001 (United States); Berggren, Susan; Palacios, Antonio [Nonlinear Dynamics Group Department of Mathematics and Statistics San Diego State University, San Diego, CA 92182 (United States); Leese de Escobar, Anna

2011-04-19

169

A method for simulating a flux-locked DC SQUID  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

170

Transfer of 60 Co from midwater squid to sperm whales  

Microsoft Academic Search

Sperm whales are notable squid-eaters. They feed mainly on medium to large-sized cephalopods at midwater levels and defecate near the surface. This suggests the existence of an upward transport of60Co by sperm whales from the mesopelagic zone (150–1,200 m). To elucidate this squid-whale route for this artificial radionuclide,60Co content was determined in squid and in predator whales captured by commercial

Takeshi Umezut; Hiroshi Ebihara; Y?ko Minamisako; Hiroshi Watanabe

1984-01-01

171

The Renormalization Effects in the Microstrip-SQUID Amplifier  

E-print Network

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.

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

2011-10-25

172

Fundamental characteristics of the QFP measured by the dc SQUID  

SciTech Connect

This paper describes the fundamental characteristics of the Quantum Flux Parametron (QFP) measured by a new method in which the output signals of the QFP are detected with a dc SQUID. The dc SQUID linearly and continuously converts the output current of the QFP to voltage, allowing the output signal of the QFP to be measured as the voltage of the dc SQUID. Thus, the fundamental characteristics of the QFP have been experimentally confirmed in detail.

Shimizu, N.; Harada, Y.; Miyamoto, N.; Hosoya, M. (Quantum Magneto Flux Logic Project, Research Development Corp. of Japan, 1-280 Higashi-koigakubo, Kokubunji, Tokyo 185 (JP)); Goto, E. (Dept. of Information Science, Univ. of Tokyo, Bunkyo-ku, Tokyo 113 (JP))

1989-06-01

173

Practical SQUID Instrument for Nondestructive Testing  

NASA Technical Reports Server (NTRS)

We report on the development of a scanning eddy-current imaging system designed to detect deep subsurface flaws in conducting materials. A high transition temperature (high-T c) superconducting quantum interference device (SQUID) magnetometer is employed to provide the required sensitivity at low frequencies, while a combination of small cylindrical high-Tc superconducting and A-metal shields enable the instrument to be scanned in a magnetically noisy environment, rather than the object under test. The shields are arranged to prevent unwanted excitation and ambient noise fields from reaching the SQUID, and to enhance spatial resolution and minimize undesirable edge effects. Thus far, the instrument has successfully detected cracks and pits through 10 layers of aluminum, with a combined thickness of 5 cm at room temperature.

Tralshawala, N.; Claycomb, J. R.; Miller, John H., Jr.

1997-01-01

174

Low Temperature SQUID for NDE Applications  

NASA Technical Reports Server (NTRS)

We have developed a low temperature SuperConducting Quantum Interference Device - SQUID measurement system for detection of defects deep under the surface of aluminum structures using eddy current techniques. The system uses a two dimensional planar inducer with two different excitation frequencies to induce a current in the sample. We have developed a data analysis software program that enabled us to distinguish between round defects (holes), straight defects (slots) and slots close to holes simulating cracks starting from rivets in aluminum structures. We were able to detect defects that are 8mm below the surface. We have also measured the change in phase of the detected signal as a function of depth of the defect. This relationship can be used to determine the depth of hidden flaws. Using this analysis software with the high temperature SQUID system at NASA Langley we were able to detect slots close to holes in layered aluminum sample.

Wincheski, Buzz (Technical Monitor); Selim, Raouf

2003-01-01

175

Practical SQUID instrument for nondestructive testing  

SciTech Connect

We report on the development of a scanning eddy-current imaging system designed to detect deep subsurface flaws in conducting materials. A high transition temperature (high-T{sub c}) superconducting quantum interference device (SQUID) magnetometer is employed to provide the required sensitivity at low frequencies, while a combination of small cylindrical high-T{sub c} superconducting and {mu}-metal shields enable the instrument to be scanned in a magnetically noisy environment, rather than the object under test. The shields are arranged to prevent unwanted excitation and ambient noise fields from reaching the SQUID, and to enhance spatial resolution and minimize undesirable edge effects. Thus far, the instrument has successfully detected cracks and pits through 10 layers of aluminum, with a combined thickness of 5 cm at room temperature. {copyright} {ital 1997 American Institute of Physics.}

Tralshawala, N.; Claycomb, J.R.; Miller, J.H. Jr. [Texas Center for Superconductivity, University of Houston, Houston, Texas 77204-5932 (United States)] [Texas Center for Superconductivity, University of Houston, Houston, Texas 77204-5932 (United States)

1997-09-01

176

SQUID-based multichannel system for Magnetoencephalography  

E-print Network

Here we present a multichannel system based on superconducting quantum interference devices (SQUIDs) for magnetoencephalography (MEG) measurements, developed and installed at Istituto di Cibernetica (ICIB) in Naples. This MEG system, consists of 163 full integrated SQUID magnetometers, 154 channels and 9 references, and has been designed to meet specifications concerning noise, dynamic range, slew rate and linearity through optimized design. The control electronics is located at room temperature and all the operations are performed inside a Magnetically Shielded Room (MSR). The system exhibits a magnetic white noise level of approximatively 5 fT/Hz1=2. This MEG system will be employed for both clinical and routine use. PACS numbers: 74.81.Fa, 85.25.Hv, 07.20.Mc, 85.25.Dq, 87.19.le, 87.85.Ng

Rombetto, S; Vettoliere, A; Trebeschi, A; Rossi, R; Russo, M

2013-01-01

177

Supersensitive SQUID/magnetostrictor detecting system  

SciTech Connect

It is shown that using the state-of-the-art quantum interferometer (SQUID) with the resolution 10{sup -6} {Phi}{sub 0} Hz{sup -1/2} = 2.07 Multiplication-Sign 10{sup -21} Wb Hz{sup -1/2}, coupled to a magnetostrictor, playing the role of tensomagnetic transducer, it is possible to construct a system for detecting pressure variations with the ultimate sensitivity of 10{sup -13} Pa Hz{sup -1/2} and for measuring specific elongation with the sensitivity of 10{sup -24} Hz{sup -1/2}. The analysis of physical grounds of the inverse magnetostriction effect demonstrates concrete ways to essentially higher efficiency of tensomagnetic conversion. The estimates performed demonstrate the possibility of using the SQUID/magnetostrictor system as a detector of gravitational waves. Other possibilities of using this system for solving both fundamental and applied problems are also considered. (experimental techniques)

Golovashkin, Aleksander I; Zherikhina, L N; Tskhovrebov, Andrei M; Izmailov, G N

2012-12-31

178

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

179

Low Field Squid MRI Devices, Components and Methods  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

180

Low field SQUID MRI devices, components and methods  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

181

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. PMID:23418818

2013-01-01

182

Low field SQUID MRI devices, components and methods  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

183

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 ~ 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

184

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

185

Single SQUID frequency-domain multiplexer for large bolometer arrays  

SciTech Connect

We describe the development of 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. We have built an eight-channel prototype and demonstrated channel separation and signal recovery.

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

2001-08-20

186

Physiological color change in squid iridophores  

Microsoft Academic Search

Evidence is presented that changes in the optical properties of active iridophores in the dermis of the squidLolliguncula brevis are the result of changes in the ultrastructure of these cells. At least two mechanisms may be involved when active cells change from non-iridescent to iridescent or change iridescent color. One is the reversible change of labile, detergent-resistant proteinaceous material within

Kay M. Cooper; Roger T. Hanlon; Bernd U. Budelmann

1990-01-01

187

SQUID Microsusceptometry of Mesoscopic Aluminum Rings  

Microsoft Academic Search

We have studied the magnetic response of a mesoscopic aluminum ring using an integrated SQUID microsusceptometer. The flux and temperature dependence of the susceptibility just below the critical temperature (1.26 K) are described very well by Ginzburg-Landau theory. By fitting our data to the Ginzburg-Landau prediction we are able to accurately measure the sample parameters. We have studied two types

Xiaxian Zhang; John C. Price

1996-01-01

188

Sodium Fluxes in Internally Dialyzed Squid Axons  

Microsoft Academic Search

The effects which alterations in the concentrations of internal sodium and high energy phosphate compounds had on the sodium influx and efflux of internally dialyzed squid axons were examined. Nine naturally occurring high energy phosphate compounds were ineffective in supporting significant sodium extrusion. These compounds were: AcP, PEP, G-3-P, ADP, AMP, GTP, CTP, PA, and UTP. 1 The compound d-ATP

F. J. Brinley; L. J. MULLINS

1968-01-01

189

Ceramic HTSC SQUID-based galvanometer  

SciTech Connect

A highly sensitive galvanometer operating at liquid-nitrogen temperature for direct and low-frequency current measurements was developed on the basis of a HTSC SQUID. The direct-current sensitivity of the galvanometer is approximately 0.5 nA at an internal resistance of about 20 ohms. Its energy resolution in the white noise region is 2 x 10 exp 21 J/Hz. 11 refs.

Uchaikin, S.V.; Hiep, L.H. (Joint Inst. for Nuclear Research, Dubna (Russian Federation))

1992-06-01

190

Brave New Biosphere: Story of a Squid  

NSDL National Science Digital Library

This Why Files informative page is part of a series that features the narrative of Bob, the bobtail squid. Bob describes the symbiotic relationship formed between his ancestors and the bioluminescent bacteria that offer him protection from predators. The next page in this series describes the relationship from the enslaved bacteria's perspective and features scientist Margaret McFall-Ngai. Links are provided to glossary terms and a bibliography.

Files, The W.

191

Controlling Blow Flies  

E-print Network

or rural settings. Based on their appearance, they can be separated into two groups ? green bottle flies and blue bottle flies. Green bottle flies are metallic green, but sometimes have a bronze tint. They are active during warm months of the year. Blue... bottle flies are metallic blue to black or purple and are active during cooler months of the year. Life Cycle The blow fly life cycle has four stages of development. A single blow fly can lay up to 2,000 eggs during its life. Eggs are de- posited...

Tomberlin, Jeffery K.

2005-10-05

192

Fabrication and characterization of shunted ?-SQUID  

SciTech Connect

In order to eliminate hysteresis, we have fabricated and characterized niobium based shunted micron size superconducting quantum interference devices (?-SQUIDs). We find a wide temperature range where these ?-SQUIDs are non-hysteretic in nature and show a very good I{sub c} vs. B oscillations in hysteretic regime and V vs. B oscillations in non-hysteretic regime. Here we report the characteristics of a shunted- ?-SQUID (Wf38LS72D5). In this device we have achieved a large voltage modulation, in non-hysteretic regime, at various temperatures including such as 1.1 mV at 6.62 K with a transfer function V{sub ?}?=?7.2mV/?{sub 0}. The figures within the original article PDF file, as supplied to AIP Publishing, were affected by a PDF-processing error. Consequently, the article re-flowed and pagination increased from 3 to 4 pages. This article was updated on 14 May 2014 to correct the PDF-processing error, with the scientific content remaining unchanged. Readers are advised that the replacement article PDF file contains an additional blank page to preserve the original pagination.

Kumar, Nikhil, E-mail: knikhil@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur - 208016 (India); Fournier, T.; Courtois, H.; Gupta, Anjan K. [Institute Neel, CNRS and Université Joseph Fourier, 25 Avenue des Martyrs, BP 166, 38042, Grenoble (France)

2014-04-24

193

Fractionation of terrestrial neon by hydrodynamic hydrogen escape from ancient steam atmospheres  

NASA Technical Reports Server (NTRS)

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 too massive to escape from the modern atmosphere. Steam atmospheres are a likely, if intermittent, feature of the accreting Earth. They occur because, on average, the energy liberated during accretion places Earth above the runaway greenhouse threshold, so that liquid water is not stable at the surface. It is found that steam atmospheres should have lasted some ten to fifty million years. Hydrogen escape would have been vigorous, but abundant heavy constituents would have been retained. There is no lack of plausible candidates; CO2, N2, or CO could all suffice. Neon can escape because it is less massive than any of the likely pollutants. Neon fractionation would have been a natural byproduct. Assuming that the initial Ne-20/Ne-22 ratio was solar, it was found that it would have taken some ten million years to effect the observed neon fractionation in a 30 bar steam atmosphere fouled with 10 bars of CO. Thicker atmospheres would have taken longer; less CO, shorter. This mechanism for fractionating neon has about the right level of efficiency. Because the lighter isotope escapes much more readily, total neon loss is pretty minimal; less than half of the initial neon endowment escapes.

Zahnle, K.

1991-01-01

194

100 h SQUID AMPLIFIERS FOR THE ULTRACRYOGENIC GRAVITATIONAL WAVE DETECTORS  

E-print Network

100 �h SQUID AMPLIFIERS FOR THE ULTRACRYOGENIC GRAVITATIONAL WAVE DETECTORS PAOLO FALFERI, MICHELE of the cryogenic resonant de­ tectors is the noise temperature of the dc SQUID amplifier used to detect the signal factor Q, the minimum detectable energy is given by the amplifier noise temperature times the Boltzmann

195

Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers  

Microsoft Academic Search

SUMMARY Squid paralarvae (hatchlings) rely predominantly on a pulsed jet for locomotion, distinguishing them from the majority of aquatic locomotors at low\\/intermediate Reynolds numbers (Re), which employ oscillatory\\/undulatory modes of propulsion. Although squid paralarvae may delineate the lower size limit of biological jet propulsion, surprisingly little is known about the hydrodynamics and propulsive efficiency of paralarval jetting within the intermediate

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

2009-01-01

196

Swimming dynamics and propulsive efficiency of squids throughout ontogeny  

E-print Network

Swimming dynamics and propulsive efficiency of squids throughout ontogeny Ian K. Bartol,1,Ã? Paul S Synopsis Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV) and kinematic

Hynes, Wayne L.

197

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

198

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

199

Effect of parasitic capacitance on dc SQUID performance  

SciTech Connect

This paper reports on the effect of parasitic capacitance C{sub p} on dc SQUID characteristics and noise performance studied using a test structure consisting of 11 identical SQUID washers with Nb films of various widths covering the slit. The measured IV characteristics are in good agreement with simulations based on a simple lumped circuit model.

Ryhanen, T.; Cantor, R.; Drung, D.; Koch, H. (Physikalisch-Technische Bundesanstalt, Institut Berlin, Abbestr. 10-12, D-1000 Berlin 10 (DE)); Seppa, H. (VTT Metrology Research Inst., Technical Research Center of Finland, Otakaari 7B, SF-02150 Espoo (FI))

1991-03-01

200

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

201

Capacitively-Coupled SQUID Bias for Time Division Multiplexing  

NASA Astrophysics Data System (ADS)

The multiplexing scheme presented in this paper is part of the readout chain of the QUBIC instrument devoted to cosmic microwave background polarization observations. It is based on time domain multiplexing using superconducting quantum interference devices (SQUIDs) to read out a large array of superconducting bolometers. The originality of the multiplexer presented here lies in the use of capacitors for the SQUID addressing. Capacitive coupling allows us to bias many SQUIDs in parallel (in a 2D topology), with low crosstalk and low power dissipation of the cryogenic front-end readout. However, capacitors in series with the SQUID require a modification of the addressing strategy. This paper presents a bias reversal technique adopted to sequentially address the SQUIDs through capacitors using a cryogenic SiGe integrated circuit. We further present the different limitations of this technique and how to choose the proper capacitance for a given multiplexing frequency and current source compliance.

Prêle, D.; Voisin, F.; Piat, M.; Martino, J.; Decourcelle, T.; Chapron, C.

2014-08-01

202

Small-signal analysis for dc SQUID amplifiers  

SciTech Connect

A small-signal analysis is presented for the dc SQUID (Superconducting QUantum Interference Device) coupled to a general-input impedance. This method differs from previous calculations by introducing perturbations of the SQUID variables into all of the equations describing a dc SQUID rather than just those describing the input circuit and the continuity of the wave function phase around the SQUID loop. From this method, one is able to determine analytic expressions for the impedance matrix, the power spectral densities of the two conjugate noise sources, and the cross-correlation power spectral density in terms of the well-known solutions of an isolated dc SQUID. Results presented are compared with the results of other techniques.

Carroll, K.R. (Univ. of Maryland, College Park (United States))

1991-03-01

203

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

204

Planar thin film SQUID with integral flux concentrator  

NASA Technical Reports Server (NTRS)

A thin film SQUID is disclosed having improved flux concentration combined with simplicity of design and fabrication. The SQUID starts with a wafer like substrate having simple planar geometry. A large area of superconducting film is coated on the substrate, with a small open or uncoated area remaining at its center to define a SQUID loop, and a gap in the film formed, beginning at the outer circumferential edge of the substrate and extending radially inward to the open area. A Josephson junction is formed across the gap near the open area to interrupt the electrical continuity of the SQUID loop. A coil is attached to the surface of the substrate, electrically insulated from the superconducting film, and is energized to induce flux within the SQUID which is concentrated within the open area.

Peters, Palmer N. (inventor); Sisk, Robert C. (inventor)

1988-01-01

205

Isotopic effects in the neon fixed point: uncertainty of the calibration data correction  

NASA Astrophysics Data System (ADS)

The neon triple point is one of the defining fixed points of the International Temperature Scale of 1990 (ITS-90). Although recognizing that natural neon is a mixture of isotopes, the ITS-90 definition only states that the neon should be of ‘natural isotopic composition’, without any further requirements. A preliminary study in 2005 indicated that most of the observed variability in the realized neon triple point temperatures within a range of about 0.5?mK can be attributed to the variability in isotopic composition among different samples of ‘natural’ neon. Based on the results of an International Project (EUROMET Project No. 770), the Consultative Committee for Thermometry decided to improve the realization of the neon fixed point by assigning the ITS-90 temperature value 24.5561?K to neon with the isotopic composition recommended by IUPAC, accompanied by a quadratic equation to take the deviations from the reference composition into account. In this paper, the uncertainties of the equation are discussed and an uncertainty budget is presented. The resulting standard uncertainty due to the isotopic effect (k = 1) after correction of the calibration data is reduced to (4 to 40)??K when using neon of ‘natural’ isotopic composition or to 30??K when using 20Ne. For comparison, an uncertainty component of 0.15?mK should be included in the uncertainty budget for the neon triple point if the isotopic composition is unknown, i.e. whenever the correction cannot be applied.

Steur, Peter P. M.; Pavese, Franco; Fellmuth, Bernd; Hermier, Yves; Hill, Kenneth D.; Seog Kim, Jin; Lipinski, Leszek; Nagao, Keisuke; Nakano, Tohru; Peruzzi, Andrea; Sparasci, Fernando; Szmyrka-Grzebyk, Anna; Tamura, Osamu; Tew, Weston L.; Valkiers, Staf; van Geel, Jan

2015-02-01

206

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

207

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

208

Oregon Sea Grant Marine Education Program at Hatfield Marine Science Center Squid Dissection  

E-print Network

adaptations they have for survival in the marine environment. Background Squid are invertebrates, meaning by numerous species of fish, birds, marine mammals and even other squid, and form a very important link organisms, squid have developed a number of specialized adaptations that help them avoid predators. Squid

Wright, Dawn Jeannine

209

ECOSYSTEMS AND SUSTAINABILITY Temporal and ontogenetic variation in the diet of squid  

E-print Network

ECOSYSTEMS AND SUSTAINABILITY Temporal and ontogenetic variation in the diet of squid (Loligo online: 6 May 2011 Ã? Springer Science+Business Media B.V. 2011 Abstract The squid Loligo forbesii by squid of all sampled sizes, although occurrence of gobies was generally more frequent in smaller squids

Pierce, Graham

210

A Single SQUID Multiplexer for Arrays of Low Temperature Sensors Jongsoo Yoona)  

E-print Network

1 A Single SQUID Multiplexer for Arrays of Low Temperature Sensors Jongsoo Yoona) , John Clarkea and experimental evaluation of a superconducting quantum interference device (SQUID) mul- tiplexer for an array, in turn, is inductively coupled to the readout SQUID. The flux-locked loop of the SQUID is used to null

Richards, Paul L.

211

The market squid (Loligo opalescens) (also known as the opalescent inshore  

E-print Network

661 The market squid (Loligo opalescens) (also known as the opalescent inshore squid, FAO [Roper et with declines in other fisheries off the U.S. West Coast. Market squid is a short-lived species (Jackson, 1994. For exam- ple, squid landings plummeted during the 1997-98 El Niño but reached a record high

212

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

213

Fly ash carbon passivation  

DOEpatents

A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

La Count, Robert B; Baltrus, John P; Kern, Douglas G

2013-05-14

214

Impedance of the Microstrip SQUID Amplifier  

NASA Astrophysics Data System (ADS)

We present measurements of the input impedance of microstrip SQUID amplifiers cooled to 4.2 K. A low-loss transmission line model fits the real and imaginary parts of this impedance quite accurately. We map the low-loss transmission line model into an equivalent parallel RLC circuit in which a resistance R, inductance L, and capacitance C are calculated from the characteristic impedance and attenuation factor determined from fits to the input impedance data. Using this equivalent RLC circuit, we model the microstrip SQUID and input network with a lumped circuit model which accurately predicts the observed gain of the amplifier. We find that the gain is maximized when the input circuit is critically matched, with the imaginary part of the input impedance summing to zero and the real part equal to the 50 ohm resistance of the coaxial input line. Work in progress is aimed at expressing the equivalent circuit parameters in terms of the device parameters. This work was supported by DOE.

Therrien, Roy; Kinion, Darin; Mueck, Michael; Clarke, John

2003-03-01

215

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

216

Bicrystal YBCO dc squids with low noise  

SciTech Connect

We have fabricated 12 dc SQUIDs by laser depositing YBa[sub 2]Cu[sub 3]O[sub 7-x] on a SrTiO[sub 3] bicrystal substrate with a misorientation angle of 24*. At 77K all twelve devices had acceptable values of critical current, resistance and voltage modulation produced by an external magnetic field. The white noise energy of one device with an estimated inductance of 41 pH was 1.8 [times] 10[sup [minus]30] JHz[sup [minus]1]. The noise power scaled as 1/f at frequencies below about 1kHz, however, by using a bias current reversal scheme we were able to reduce this noise by two orders of magnitude at 1 Hz, to a value of about 1.5 [times] 10[sup [minus]29] JHz[sup [minus]1]. We made a magnetometer by coupling the SQUID to a flux transformer with a 5-turn input coil. The measured magnetic field gain was 60, and the white noise 36fT Hz[sup [minus][1/2

Miklich, A.H.; Koelle, D.; Dantsker, E.; Nemeth, D.T.; Kingston, J.J.; Kromann, R.F.; Clarke, J.

1992-08-01

217

Bicrystal YBCO dc squids with low noise  

SciTech Connect

We have fabricated 12 dc SQUIDs by laser depositing YBa{sub 2}Cu{sub 3}O{sub 7-x} on a SrTiO{sub 3} bicrystal substrate with a misorientation angle of 24*. At 77K all twelve devices had acceptable values of critical current, resistance and voltage modulation produced by an external magnetic field. The white noise energy of one device with an estimated inductance of 41 pH was 1.8 {times} 10{sup {minus}30} JHz{sup {minus}1}. The noise power scaled as 1/f at frequencies below about 1kHz, however, by using a bias current reversal scheme we were able to reduce this noise by two orders of magnitude at 1 Hz, to a value of about 1.5 {times} 10{sup {minus}29} JHz{sup {minus}1}. We made a magnetometer by coupling the SQUID to a flux transformer with a 5-turn input coil. The measured magnetic field gain was 60, and the white noise 36fT Hz{sup {minus}{1/2}}. However, the transformer produced relatively large levels of 1/f flux noise, not reduced by the bias reversal scheme, that limited the noise at 1 Hz to 1.7 pT Hz{sup {minus}{1/2}}. A single-layer magnetometer with a single-turn pick up loop is briefly described.

Miklich, A.H.; Koelle, D.; Dantsker, E.; Nemeth, D.T.; Kingston, J.J.; Kromann, R.F.; Clarke, J.

1992-08-01

218

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

219

Cross-linking Chemistry of Squid Beak*  

PubMed Central

In stark contrast to most aggressive predators, Dosidicus gigas (jumbo squids) do not use minerals in their powerful mouthparts known as beaks. Their beaks instead consist of a highly sclerotized chitinous composite with incremental hydration from the tip to the base. We previously reported l-3,4-dihydroxyphenylalanine (dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material. Here, we present a more complete characterization of the sclerotization chemistry and describe additional cross-links from D. gigas beak. All cross-links presented in this report share common building blocks, a family of di-, tri-, and tetra-histidine-catecholic adducts, that were separated by affinity chromatography and high performance liquid chromatography (HPLC) and identified by tandem mass spectroscopy and proton nuclear magnetic resonance (1H NMR). The data provide additional insights into the unusually high cross-link density found in mature beaks. Furthermore, we propose both a low molecular weight catechol, and peptidyl-dopa, to be sclerotization agents of squid beak. This appears to represent a new strategy for forming hard tissue in animals. The interplay between covalent cross-linking and dehydration on the graded properties of the beaks is discussed. PMID:20870720

Miserez, Ali; Rubin, Daniel; Waite, J. Herbert

2010-01-01

220

Recent Results of a New Microwave SQUID Multiplexer  

NASA Technical Reports Server (NTRS)

We are developing a proof-of-concept microwave SQUID multiplexer containing four SQUIDs coupled to GHz frequency resonant circuits and fed with a single microwave readout line. The resonators are half-wave coplanar waveguide sections and are similar to the structures used for the microwave kinetic inductance detectors developed in our group. Optimal values for the interdigital gap capacitors were determined to maximize the sensitivity of the transmitted and reflected microwave signal with respect to changes in the dynamic resistance of the SQUID. The dc current-bias line for the SQUID has an in-line inductive high frequency filter to minimize coupling between the bias line and resonator. A high frequency modulation scheme is proposed to eliminate the need for individual flux biasing of the SQUIDs, which extends the dynamic range of the readout. In this scheme a common modulation signal is imposed on each SQUID and the received signal is demodulated at one and two times the modulation frequency to maintain sensitivity at any flux state. We present the recent results of the microwave SQUID multiplexer system operating at a readout frequency range of 10 - 11GHz.

Hahn, Inseob; Limketkai, B.; Bumble, B.; LeDuc, H. G.

2007-01-01

221

Multistability and self-organization in disordered SQUID metamaterials  

NASA Astrophysics Data System (ADS)

Planar arrays of magnetoinductively coupled rf SQUIDs (Superconducting QUantum Interference Devices) belong to the emergent class of superconducting metamaterials that encompass the Josephson effect. These SQUID-based metamaterials acquire their electromagnetic properties from the resonant characteristics of their constitutive elements, i.e., the individual rf SQUIDs. In its simplest version, an rf SQUID consists of a superconducting ring interrupted by a Josephson junction. We investigate numerically the response of a two-dimensional rf SQUID metamaterial with respect to the driving frequency of an externally applied alternating magnetic field in the presence of disorder arising from critical current fluctuations of the Josephson elements; in effect, the resonance frequencies of individual SQUIDs are distributed randomly around a mean value. Bistability is observed in the current amplitude-frequency curves both in ordered and disordered SQUID metamaterials; moreover, bistability is favored by disorder through the improvement of synchronization between SQUID oscillators. Relatively weak disorder widens significantly the bistability region by helping the system to self-organize and leads to nearly homogeneous states that change smoothly with varying driving frequency. Also, the total current of the metamaterial is enhanced, compared with that of uncoupled SQUIDs, through the synergetic action of coupling and synchronization. The existence of simultaneously stable states that provide either high or low total current, allows the metamaterial to exhibit different magnetic responses that correspond to different values of the effective magnetic permeability. At low power of the incident field, high current amplitude states exhibit extreme diamagnetic properties corresponding to negative magnetic permeability in a narrow frequency interval.

Lazarides, N.; Tsironis, G. P.

2013-08-01

222

Alpha and beta particle induced scintillations in liquid and solid neon  

Microsoft Academic Search

Scintillations induced by alpha and beta particles in liquid and solid neon are studied and their light yield measured. Charged particle scintillation in neon is primarily in the extreme ultraviolet (EUV). We detect this EUV light by converting it to blue using a wavelength shifting fluor and detecting the blue light with a photomultiplier tube. It is observed that liquid

R. A. Michniak; R. Alleaume; D. N. McKinsey; J. M. Doyle

2002-01-01

223

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

224

Applications of neon, nitrogen, argon and oxygen to physical, chemical and biological cycles in the ocean  

E-print Network

Applications of neon, nitrogen, argon and oxygen to physical, chemical and biological cycles;#12;University of Washington Abstract Applications of neon, nitrogen, argon and oxygen to physical, chemical and biological cycles in the ocean by Roberta Claire Hamme Chair of Supervisory Committee: Professor Steven R

Hamme, Roberta C.

225

Mechanisms controlling the global oceanic distribution of the inert gases argon, nitrogen and neon  

E-print Network

Mechanisms controlling the global oceanic distribution of the inert gases argon, nitrogen and neon formation. We present argon, nitrogen, and neon data from the subtropical and subpolar North Pacific-mediated gas exchange. This result suggests that these three processes are the first order controls

Emerson, Steven R.

226

Inexpensive THz Focal Plane Array Imaging Using Miniature Neon Indicator Lamps as Detectors  

Microsoft Academic Search

Development of focal plane arrays (FPAs) for mm wavelength and THz radiation is presented in this paper. The FPA is based upon inexpensive neon indicator lamp Glow Discharge Detectors (GDDs) that serve as pixels in the FPA. It was shown in previous investigations that inexpensive neon indicator lamp GDDs are quite sensitive to mm wavelength and THz radiation. The diameters

Daniel Rozban; Assaf Levanon; Hezi Joseph; Avihai Akram; Amir Abramovich; Natan S. Kopeika; Yitzhak Yitzhaky; Alexander Belenky; Orly Yadid-Pecht

2011-01-01

227

Spectroscopic study of neon emission and retention in the Tore Supra ergodic divertor  

Microsoft Academic Search

In order to assess the capability of the Tore Supra ergodic divertor (ED) to retain impurities in the low confinement edge region, spectroscopic observations of a divertor neutraliser plate are reported. The neutral neon density is deduced from these measurements; it increases strongly (up to 1.5×1017 m?3 per injected Pa l) when the plasma approaches detachment. The central neon density

R. Guirlet; J. Hogan; Y. Corre; C. De Michelis; A. Escarguel; W. Hess; P. Moniergarbet; B. Schunke

2001-01-01

228

Mantle hotspot neon in basalts from the Northwest Lau Back-arc Basin  

E-print Network

Mantle hotspot neon in basalts from the Northwest Lau Back-arc Basin J. E. Lupton,1 R. J. Arculus,2 2012; published 28 April 2012. [1] The neon isotope compositions of basalts from the Northwest Lau Back-arc Basin reflect three-component mixing between an ocean island basalt (OIB) mantle hotspot component, mid

Graham, David W.

229

Decoherence and Recoherence in a Vibrating RF SQUID  

E-print Network

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 oscillations between the two lowest energy states of the RF SQUID. We address the feasibility of experimental observation of decoherence and recoherence, namely decay and rise of the visibility, in such a system.

Eyal Buks; M. P. Blencowe

2006-07-16

230

A dc SQUID for use below 1 K  

SciTech Connect

For detection of weak signals, and for use on ultralow temperature experiments, it would be useful to have a robust superconducting quantum interference device (SQUID) amplifier that works below 1 K. We report on a test of a commercial SQUID amplifier that has lower noise than others we have tested, and works well while attached to a 50-mK chamber. The SQUID noise was improved only modestly when cooled from 4 K to 50 mK. The best energy resolution measured was 2200 [h bar].

Geng, Z.K.; Adams, P.W.; Hamilton, W.O.; Johnson, W.W.; Solomonson, N.D. (Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (United States))

1993-05-01

231

Decoherence and Recoherence in a Vibrating RF SQUID  

E-print Network

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 oscillations between the two lowest energy states of the RF SQUID. We address the feasibility of experimental observation of decoherence and recoherence, namely decay and rise of the visibility, in such a system.

Buks, E; Buks, Eyal

2006-01-01

232

Stochastic Resonance for a SQUID with Dichotomous Resistance  

NASA Astrophysics Data System (ADS)

We investigate the response to the ac current for a superconducting quantum interference device (SQUID) with a dichotomous resistance. It is shown that, for some suitably selected parameters' values, stochastic resonance appears for the amplitude of the stationary average voltage of the SQUID versus the correlation time of the dichotomous noise. Our result can provide some useful insights for the investigation of the response of the SQUID (especially for the ones with the nano junctions) to the temporal-periodic signal (including the input ac current, the irradiation microwave, the detected temporal-periodic signal, and the added ac voltage).

Li, Jing-Hui

2014-03-01

233

HTS ion damage Josephson junction technology for SQUID arrays  

NASA Astrophysics Data System (ADS)

The high temperature superconducting (HTS) Josephson Junction (JJ) ion damage technology we are developing is well suited for making large SQUID arrays. We have studied arrays of similar SQUIDs together with large SQIFs (Superconducting Quantum Interference Filter) with 2000 SQUIDs of different loop areas. Magnetic field sensitivity has been measured in both types of devices as a function of bias current and temperature. The effects of the barrier thickness (from 20 to 80 nm) and JJ length (2 or 5 ?m) on characteristics have been investigated.

Ouanani, S.; Kermorvant, J.; Crété, D.-G.; Lemaître, Y.; Mage, J.-C.; Marcilhac, B.; Bergeal, N.; Malnou, M.; Lesueur, J.; Mailly, D.; Ulysse, C.

2014-05-01

234

Flying Over Atoms  

NSDL National Science Digital Library

Flying Over Atoms provides tools for teaching about atoms and solid surfaces in an introductory chemistry course. Flying Over Atoms introduces and stimulates interest in atomic surfaces and current methods for imaging at the atomic scale. Flying over Atoms uses Scanning Tunneling Microscope (STM) data and the software program Vistapro, published by Rom Tech, Inc. (not provided) to allow students to create QuickTime movies of atomic landscapes.

235

Deep-Sea Research I 51 (2004) 15171528 The solubility of neon, nitrogen and argon in distilled water  

E-print Network

Deep-Sea Research I 51 (2004) 1517­1528 The solubility of neon, nitrogen and argon in distilled of these gases. We present new solubility measurements for neon, nitrogen and argon in distilled water reserved. Keywords: Gas solubility; Saturation; Neon; Nitrogen; Argon; Inert gases 1. Introduction

Emerson, Steven R.

236

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

NASA Astrophysics Data System (ADS)

A low-temperature, high-energy (50keV) 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 probed for different sizes up to approximately 3×104 atoms. The analysis is based on a comparison of precise experimental and calculated diffracted intensities with the help of a minimization procedure for the reliability factor R. Highly reproducible discrete distribution functions of sizes and structures are found. The time-dependent evolution of diffractograms at earlier stages of growth is revealed. Initially distinct diffraction peaks gradually "disappear," although the total electron beam absorption attests that the deposited neon is preserved in the porous substrate. We ascribe this effect to diffusion-like gas penetration from larger to smaller pores, which results in a highly dispersed or even disordered substance. Evidently, the clusters that grow initially during deposition are later soaked up by a sponge-like substrate due to capillary forces.

Krainyukova, N. V.

2007-06-01

237

Helium-neon laser treatment transforms fibroblasts into myofibroblasts.  

PubMed Central

The differentiation of myofibroblastic cells from normal human gingival fibroblasts in vitro has been established by transmission electron microscopy and quantitated by immunohistochemistry, using antigelsolin monoclonal antibodies. Untreated control cultures were compared to cultures exposed to Helium-Neon (He-Ne) laser irradiation. A direct and massive transformation of the cultured fibroblasts into myofibroblasts was observed as early as 24 hours after laser treatment, whereas control cultures were comprised of only resting fibroblasts and active fibroblasts. This in vitro induction of myofibroblasts may be analogous to that which occurs in vivo. Therefore we undertook a similar study using biopsies from gingival tissues after wisdom tooth extraction. Myofibroblasts were present in the connective tissue of laser-treated gums 48 hours after irradiation, but not in untreated contralateral control tissues. These data provide evidence that the primary biologic effect of the Helium-Neon laser on connective tissue is the rapid generation of myofibroblasts from fibroblasts. The induction of a phenotype with contractile properties may have clinical significance in the acceleration of the wound-healing process. Images Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:2372040

Pourreau-Schneider, N.; Ahmed, A.; Soudry, M.; Jacquemier, J.; Kopp, F.; Franquin, J. C.; Martin, P. M.

1990-01-01

238

Infrared spectra of small molecular ions trapped in solid neon  

NASA Astrophysics Data System (ADS)

The infrared spectrum of a molecular ion provides a unique signature for that species, gives information on its structure, and is amenable to remote sensing. It also serves as a comparison standard for refining ab initio calculations. Experiments in this laboratory trap molecular ions in dilute solid solution in neon at 4.2 K in sufficient concentration for observation of their infrared spectra between 450 and 4000 cm!1. Discharge-excited neon atoms produce cations by photoionization and/or Penning ionization of the parent molecule. The resulting electrons are captured by other molecules, yielding anions which provide for overall charge neutrality of the deposit. Recent observations of ions produced from C2H4 and BF3 will be discussed. Because of their relatively large possibility of having low-lying excited electronic states, small, symmetric molecular cations are especially vulnerable to breakdown of the Born-Oppenheimer approximation. Some phenomena which can result from this breakdown will be discussed. Ion-molecule reaction rates are sufficiently high that in some systems absorptions of dimer cations and anions are also observed. When H2 is introduced into the system, the initially-formed ion may react with it. Among the species resulting from such ion-molecule reactions that have recently been studied are O4+, NH4+, HOCO+, and HCO2!.

Jacox, Marilyn E.

2015-01-01

239

Helium-neon laser treatment transforms fibroblasts into myofibroblasts  

SciTech Connect

The differentiation of myofibroblastic cells from normal human gingival fibroblasts in vitro has been established by transmission electron microscopy and quantitated by immunohistochemistry, using antigelsolin monoclonal antibodies. Untreated control cultures were compared to cultures exposed to Helium-Neon (He-Ne) laser irradiation. A direct and massive transformation of the cultured fibroblasts into myofibroblasts was observed as early as 24 hours after laser treatment, whereas control cultures were comprised of only resting fibroblasts and active fibroblasts. This in vitro induction of myofibroblasts may be analogous to that which occurs in vivo. Therefore we undertook a similar study using biopsies from gingival tissues after wisdom tooth extraction. Myofibroblasts were present in the connective tissue of laser-treated gums 48 hours after irradiation, but not in untreated contralateral control tissues. These data provide evidence that the primary biologic effect of the Helium-Neon laser on connective tissue is the rapid generation of myofibroblasts from fibroblasts. The induction of a phenotype with contractile properties may have clinical significance in the acceleration of the wound-healing process.

Pourreau-Schneider, N.; Ahmed, A.; Soudry, M.; Jacquemier, J.; Kopp, F.; Franquin, J.C.; Martin, P.M. (CNRS Unite 1175, Marseille (France))

1990-07-01

240

Improved Microwave Amplifiers Based on the dc SQUID  

NASA Astrophysics Data System (ADS)

The dc SQUID can be used as a sensitive microwave amplifier if the signal to be amplified is suitably coupled to the SQUID. We have designed and fabricated microwave amplifiers in which a coil integrated on top of the SQUID is operated as a half-wavelength-microstrip resonator. Such amplifiers have a power gain of up to 100 at 1 GHz, and 4 at 8 GHz. When cooled to millikelvin temperatures, sensitivities close to the quantum limited could be obtained at 500 MHz. By applying negative feedback and adding a few passive components, the input and output impedances of the amplifiers can be brought close to 50 ohms, with only a modest reduction in gain. The robust match to 50 ohms makes it possible to cascade multiple SQUID gain stages, and thereby enhance device performance. We describe novel configurations of the input resonator that allow operation at higher frequencies, and discuss application of these amplifiers to the readout of superconducting quantum circuits.

Chen, Yung-Fu; Hover, David; Maurer, Leon; Sendelbach, Steve; McDermott, Robert; Mueck, Michael

2010-03-01

241

Introduction Cephalopods (squid, cuttlefish, octopus) can produce a variety of  

E-print Network

2133 Introduction Cephalopods (squid, cuttlefish, octopus) can produce a variety of body patterns) is equally impressive, such as the zebra display in cuttlefish and the passing cloud display of various

Hanlon, Roger T.

242

Signal and noise characteristics of bi-SQUID  

NASA Astrophysics Data System (ADS)

We present an improved analytic theory, numerical simulation, and analysis of noise characteristics of a bi-SQUID in comparison with those of a dc SQUID in an open loop configuration. The analytic theory which had been developed earlier, neglecting a pulse component of the difference of the phases of Josephson junctions, is now completed taking into account the pulse component. In the bi-SQUID, the additional Josephson junction introduces another source of fluctuations and changes its transfer function, nonlinear dynamics, and the noise spectrum transformation. Some increase in the reduced-to-input noise at low values of applied magnetic flux comes from the nonlinear flux to phase difference transformation that was introduced in bi-SQUID as a way to linearize its voltage response.

Kornev, V. K.; Sharafiev, A. V.; Soloviev, I. I.; Mukhanov, O. A.

2014-11-01

243

Development of a colorimetric sensor array for squid spoilage assessment.  

PubMed

The aim of this work was to develop and evaluate a rapid, easy-to-use optoelectronic system for the shelf-life assessment of squid in cold storage. For this purpose, an optoelectronic nose was designed, which consisted of an array containing six sensing materials prepared by combining different dyes and two inorganic supports (aluminium oxide and silica gel). Samples were packaged with the colorimetric array and kept in cold storage for 12days. Squid spoilage was monitored simultaneously by the colorimetric array and by the physico-chemical and microbial analyses during storage. Samples exceeded the acceptability limits for microbial counts on the third day. PCA analysis carried out with CIELab showed that the colorimetric array was able to discriminate between fresh squid fit for consumption and spoiled squid. The statistical models obtained by PLS, with the optoelectronic nose, successfully predicted CO2 and O2 content in the headspace as well as microbial growth. PMID:25577086

Zaragozá, Patricia; Fuentes, Ana; Ruiz-Rico, María; Vivancos, José-Luis; Fernández-Segovia, Isabel; Ros-Lis, José V; Barat, José M; Martínez-Máñez, Ramón

2015-05-15

244

SCHOOL STRUCTURE OF THE SQUID LOLIGO OPALESCENS ANN C. HURLEY!  

E-print Network

3 m rectangular Plexiglas2 tank which was filled to a depth of 0.4 m. The tank was painted flat. In the laboratory, the squid were maintained in a 3-m diameter circular tank with rapidly circulating seawater

245

Squid as nutrient vectors linking Southwest Atlantic marine ecosystems  

NASA Astrophysics Data System (ADS)

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

Arkhipkin, Alexander I.

2013-10-01

246

Nonstandard applications of superconducting quantum interferometers: SQUIDS (Review)  

SciTech Connect

Some applications of superconducting quantum interferometers are studied. The problems of quantum noise in the Josephson junction are discussed, theoretical estimates of their magnitude are given, and ways for achieving the limiting sensitivity of SQUIDs are indicated. Applications of SQUIDs in checking some basic physical laws (Newton's law, the principle of equivalence of inertial and gravitational masses, general relativity), in elementary particle physics (search for quarks and magnetic monopoles), in geophysics (magnetotelluric measurements, gradiometric measurements, gravimetric experiments, etc.), and in ultra-low-temperature physics (nuclear gyroscope, SQUIDs and NMR, ultra-low-temperature thermometry) are described. Both past and future experiments are studied and some further applications of SQUID-based magnetometers are indicated.

Odegnal, M.

1985-01-01

247

Experimental Realization of Josephson Junctions for an Atom SQUID  

NASA Astrophysics Data System (ADS)

We report the creation of a pair of Josephson junctions on a toroidal dilute gas Bose-Einstein condensate (BEC), a configuration that is the cold atom analog of the well-known dc superconducting quantum interference device (SQUID). We observe Josephson effects, measure the critical current of the junctions, and find dynamic behavior that is in good agreement with the simple Josephson equations for a tunnel junction with the ideal sinusoidal current-phase relation expected for the parameters of the experiment. The junctions and toroidal trap are created with the painted potential, a time-averaged optical dipole potential technique which will allow scaling to more complex BEC circuit geometries than the single atom-SQUID case reported here. Since rotation plays the same role in the atom SQUID as magnetic field does in the dc SQUID magnetometer, the device has potential as a compact rotation sensor.

Ryu, C.; Blackburn, P. W.; Blinova, A. A.; Boshier, M. G.

2013-11-01

248

Weld quality evaluation using a high temperature SQUID array  

SciTech Connect

This paper presents preliminary data for evaluating weld quality using high temperature SQUIDS. The SQUIDS are integrated into an instrument known as the SQUID Array Microscope, or SAMi. The array consists of ll SQUIDs evenly distributed over an 8.25 mm baseline. Welds are detected using SAMi by using an on board coil to induce eddy currents in a conducting sample and measuring the resulting magnetic fields. The concept is that the induced magnetic fields will differ in parts of varying weld quality. The data presented here was collected from three stainless steel parts using SAMi. Each part was either solid, included a good weld, or included a bad weld. The induced magnetic field's magnitude and phase relative to the induction signal were measured. For each sample considered, both the magnitude and phase data were measurably different than the other two samples. These results indicate that it is possible to use SAMi to evaluate weld quality.

Clark, D. D. (David D.); Espy, M. A. (Michelle A.); Kraus, Robert H., Jr.; Matlachov, A. N. (Andrei N.); Lamb, J. S. (Jessica S.)

2002-01-01

249

Double dc SQUID for flux-locked-loop operation  

SciTech Connect

A novel double dc superconducting quantum interference device (SQUID) is proposed. It consists of two SQUIDs with different geometries in cascade configuration. The structure makes the device particularly suitable for flux-locked-loop operation without need of a room-temperature heterodyne modulation circuitry and a matching network between the SQUID and the preamplifier, thus simplifying the readout electronic system. The noise performance is calculated as a function of the electrical parameters of the device. The noise contribution of the room-temperature preamplifier can be made negligible using {lt}m1; 2p{gt}appropriate SQUID parameters while the slew rate of the system can approach 10{sup 6}{Phi}{sub 0}/s.

Foglietti, V. (IESS-CNR, Via Cineto Romano 42, Roma, Italy (IT))

1991-07-22

250

Dc-SQUID sensor system for multichannel neuromagnetometry  

SciTech Connect

This paper reports on various DC-SQUID sensor configurations developed for use in the authors' 19-channel neuromagetometer. Apart from the standard type, resistively and indictively shunted SQUIDs were made, allowing for a large screening factor {beta} ({gt}1). In this way signal coupling from the pick-up coil to the SQUID is facilitated and capactive coupling between the input coil and the SQUID washer can be decreased. The number of turns of the input coil is decreased further by allowing for an inductance mismatch in the input circuit. Although theoretically both measures give rise to an increased field noise of the sensor, they may lead to a reduction of the excess noise and the noise balance may become positive.

Houwman, E.P.; Veldhuis, D.; Flokstra, ter Brake, H.J.M.; Jaszczuk, W.; Rogalla, H. (Univ. of Twente, Faculty of Applied Physics, P.O. Box 217, 7500 AE Enschede (NL)); Martinez, A. (Universidad de Zaragoza, E.T.S.I.I. Maria Zambrano 50, 50015 Zaragoza (ES))

1991-03-01

251

Experimental realization of Josephson junctions for an atom SQUID.  

PubMed

We report the creation of a pair of Josephson junctions on a toroidal dilute gas Bose-Einstein condensate (BEC), a configuration that is the cold atom analog of the well-known dc superconducting quantum interference device (SQUID). We observe Josephson effects, measure the critical current of the junctions, and find dynamic behavior that is in good agreement with the simple Josephson equations for a tunnel junction with the ideal sinusoidal current-phase relation expected for the parameters of the experiment. The junctions and toroidal trap are created with the painted potential, a time-averaged optical dipole potential technique which will allow scaling to more complex BEC circuit geometries than the single atom-SQUID case reported here. Since rotation plays the same role in the atom SQUID as magnetic field does in the dc SQUID magnetometer, the device has potential as a compact rotation sensor. PMID:24289693

Ryu, C; Blackburn, P W; Blinova, A A; Boshier, M G

2013-11-15

252

SQUID Microsusceptometry of Mesoscopic Aluminum Rings  

NASA Astrophysics Data System (ADS)

We have studied the magnetic response of a mesoscopic aluminum ring using an integrated SQUID microsusceptometer. The flux and temperature dependence of the susceptibility just below the critical temperature (1.26 K) are described very well by Ginzburg-Landau theory. By fitting our data to the Ginzburg-Landau prediction we are able to accurately measure the sample parameters. We have studied two types of fluctuation effects: thermally induced phase slip transtions between metastable states, and the equilibrium fluctutation susceptibility just above the mean-field critical temperature. The phase slip rate varies by over five orders of magnitude when the applied flux is changed by as little as one hundredth of a flux quantum. We compare the phase slip rates with predtions of an Ambegaokar-Langer type theory. The fluctuation susceptibilty is visible over a 20 mK region just above the critical tempearture. The magnitude of the fluctuation susceptibility is larger than predicted by a thermodynamic theory.

Zhang, Xiaxian; Price, John C.

1996-03-01

253

NEON, Establishing a Standardized Network for Groundwater Observations  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is establishing a standardized set of data collection systems comprised of in-situ sensors and observational sampling to obtain data fundamental to the analysis of environmental change at a continental scale. NEON will be collecting aquatic, terrestrial, and atmospheric data using Observatory-wide standardized designs and methods via a systems engineering approach. This approach ensures a wealth of high quality data, data algorithms, and models that will be freely accessible to all communities such as academic researchers, policy makers, and the general public. The project is established to provide 30 years of data which will enable prediction and forecasting of drivers and responses of ecological change at scales ranging from localized responses through regional gradients and up to the continental scale. The Observatory is a distributed system of sites spread across the United States, including Alaska, Hawaii, and Puerto Rico, which is subdivided into 20 statistically unique domains, based on a set of 18 ecologically important parameters. Each domain contains at least one core aquatic and terrestrial site which are located in unmanaged lands, and up to 2 additional sites selected to study domain specific questions such as nitrogen deposition gradients and responses of land use change activities on the ecosystem. Here, we present the development of NEON's groundwater observation well network design and the timing strategy for sampling groundwater chemistry. Shallow well networks, up to 100 feet in depth, will be installed at NEON aquatic sites and will allow for observation of localized ecohydrologic site conditions, by providing basic spatio-temporal near-real time data on groundwater parameters (level, temperature, conductivity) collected from in situ high-resolution instrumentation positioned in each well; and biannual sampling of geochemical and nutrient (N and P) concentrations in a subset of wells for each site. These data will be used to calculate several higher level data products such as hydrologic gradients which drive nutrient fluxes and their change over time. When coupled with other NEON data products, these data will allow for examining surface water/groundwater interactions as well as additional terrestrial and aquatic linkages, such as riparian vegetation response to changing ecohydrologic conditions (i.e. groundwater withdraw for irrigation, land use change) and natural sources (i.e. drought and changing precipitation patterns). This work will present the well network arrays designed for the different types of aquatic sites (1st/2nd order streams, larger rivers, and lakes) including variations on the well network designs for sites where physical constraints hinder a consistent design due to topographic (steep topography, wetlands) or physical constraints (such as permafrost). A generalized sampling strategy for each type of environment will also be detailed indicating the time of year, largely governed by hydrologic conditions, when sampling should take place to provide consistent groundwater chemistry data to allow for analyzing geochemical trends spatially across the network and through time.

Fitzgerald, M.; Schroeter, N.; Goodman, K. J.; Roehm, C. L.

2013-12-01

254

Highly Sensitive and Easy-to-Use SQUID Sensors  

Microsoft Academic Search

We have developed a novel family of low-noise superconducting quantum interference devices (SQUIDs) to cover a wide range of applications. These sensors are robust and easy to use without compromising noise performance. They are optimized for operation with our high-speed direct-coupled flux-locked loop (FLL) electronics XXF-1. For the readout of cryogenic detectors, series arrays of 16 SQUIDs with 3 nH

D.. Drung; C.. Assmann; J.. Beyer; A.. Kirste; M.. Peters; F.. Ruede; T.. Schurig

2007-01-01

255

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.

256

Sensitive high-Tc SQUID magnetometers for unshielded operation  

Microsoft Academic Search

We have developed sensitive highly reliable high-Tc SQUID magnetometers a reproducible SNS junction fabrication process. In order to enable unshielded operation in the earth's field, we have incorporated flux dams into direct-coupled SQUID magnetometers. By using up to four pickup coils in parallel, each with its own flux dam, an effective area of 0.57 mm2 has been achieved on 24

M. S. Dilorio; K. Yang; S. Yoshizumi; S. G. Haupt; D. Haran; R. H. Koch; F. P. Milliken; J. R. Rozen; D. K. Lathrop; S. Kumar

1999-01-01

257

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

NASA Technical Reports Server (NTRS)

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

258

Characterization of thermal aging of duplex stainless steel by SQUID  

SciTech Connect

Thermal aging is a growing concern for long-term-aged duplex stainless steel piping in nuclear power plants. Superconducting QUantum Interference Device (SQUID) was used for the detection of thermal aging of SUS329 rolled duplex stainless steel and SCS16 cast duplex stainless steel. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the changes in electromagnetic properties due to thermal aging.

Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F. [Nuclear Fuel Industries, Ltd., Osaka (Japan)

1995-08-01

259

Chaos generated noise in radio frequency SQUID magnetometers  

SciTech Connect

In this paper we consider from a theoretical viewpoint the interaction between a single macroscopic quantum object (a SQUID ring) and a classical circuit apparatus (a radio frequency resonant circuit). We demonstrate that chaotic solutions exist for this coupled system over a wide range of parameters and that this chaotic behaviour is determined by the quantum state of the SQUID ring. {copyright} {ital 1996 American Institute of Physics.}

Diggins, J.; Ralph, J.F.; Spiller, T.P.; Clark, T.D.; Prance, H.; Prance, R.J. [Physics Division, School of Mathematical and Physical Sciences, University of Sussex, Brighton, Sussex, BN1 9QH (United Kingdom); Brouers, F. [Physics Department, University of Liege, Sart Tilman, Liege 4000 (Belgium)

1996-05-01

260

SQUID magnetometry applied as non-invasive electroanalytic chemical technique  

SciTech Connect

This paper reports on a SQUID magnetometer, employed as a highly sensitive ammeter, used to perform standard electroanalytic chemical measurements non- invasively. Specifically, the magnetic fields generated by the net ionic movement in the solution of a driven electrochemical system is detected by the gradiometer coils. The SQUID signal can then be compared to conventional current measurements. One such standard measurement investigated is Cyclic Voltametry (CV) which determines the I-V characteristics of an electrochemical system yielding critical kinetic parameters.

Jette, B.D.; MacVicar, M.L.A. (Specialty Materials Lab., Massachusetts Inst. of Technology, Cambridge, MA (US))

1991-03-01

261

Mutant Fruit Flies  

NSDL National Science Digital Library

A general audience discussion of common fruit fly mutations. The site includes simplified illustrations, and a discussion of fruit fly chromosomes. Presented by Exploratorium at the museum of science art and human perception at the Palace of Fine Arts San Francisco.

0000-00-00

262

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.

2013-02-25

263

Activation of fly ash  

DOEpatents

Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

Corbin, D.R.; Velenyi, L.J.; Pepera, M.A.; Dolhyj, S.R.

1986-08-19

264

High-{Tc} DC SQUID and flux transformer development  

SciTech Connect

A description is presented of the fabrication and properties of high {Tc} DC SQUIDS and flux transformers fabricated by dry processing of pulsed laser ablated YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (YBCO) thin films. SQUIDs have been fabricated with either bicrystal substrate or step edge junctions. For all devices fabricated thus far, measurements indicate a similar character to the flux noise spectra with a significant 1/f noise component below 100--500 Hz. The transfer function and energy sensitivities as a function of SQUID inductances in the range 60--200 pH have been measured for bicrystal DC SQUIDs and compared with estimates. Various techniques have been employed to improve the magnetic field sensitivity of the uncoupled DC SQUID toward more practical levels including the use of large area washers, single layer magnetometers and 3-level flux transformers fabricated from trilayers of YBCO/SrTiO{sub 3}/YBCO. The properties of open input coils are presented as well as the performance of closed loop transformers coupled via flip chip geometry to the SQUID washer. A white magnetic noise level of {approx} 130 fT rms/{radical}Hz above 200 Hz has been reached with a flux transformer with a 15 turn input coil and pick-up loop area of 13 mm{sup 2}.

Fife, A.A.; Angus, V.; Betts, K. [CTF Systems Inc., Port Coquitlam, British Columbia (Canada)] [and others

1994-12-31

265

DC and RF Measurements of Serial Bi-SQUID Arrays  

E-print Network

SQUID arrays are promising candidates for low profile antennas and low noise amplifier applications. We present the integrated circuit designs and results of DC and RF measurements of the wideband serial arrays based on integration of linear bi-SQUID cells forming a Superconducting Quantum Interference Filter (bi-SQUID SQIF). Various configurations of serial arrays designs are described. The measured linearity, power gain, and noise temperature are analyzed and compared. The experimental results are matched to results of mathematical modeling. A serial bi-SQUID SQIF arrays are mounted into a coplanar waveguide (CPW) and symmetrically grounded to corresponding sides of CPW. The RF output comes out from the central common line, which is also used for DC biasing and forms a symmetrical balanced output. The signal and DC flux biasing line is designed as coplanar lines passed in parallel over each bi-SQUID cell in a bidirectional fashion concentrating magnetic flux inside of each cell. Serial bi-SQUID SQIF arrays ...

Prokopenko, G V; de Escobar, A Leese; Taylor, B; de Andrade, M C; Berggren, S; Longhini, P; Palacios, A; Nisenoff, M; Fagaly, R L

2012-01-01

266

A scanning SQUID microscope with 200 MHz bandwidth  

NASA Astrophysics Data System (ADS)

We developed a scanning DC SQUID microscope with novel readout electronics capable of wideband sensing of RF magnetic fields from 50 to 200 MHz and simultaneously providing closed-loop response at kHz frequencies. To overcome the 20 MHz bandwidth limitation of traditional closed-loop SQUIDs, a flux-modulated closed-loop simultaneously locks the SQUID quasi-static flux and flux-biases the SQUID for amplification of the RF flux up to ?0/4 in amplitude. Demodulating the SQUID voltage with a double lock-in technique yields a signal representative of both the amplitude and phase of the RF flux. This provides 80 dB of a linear dynamic range with a flux noise density of 4 ??0 Hz-1/2 at 200 MHz for a Y Ba2Cu3O7 bi-crystal SQUID at 77 K. We describe the electronics’ performance and present images for RF magnetic field of the travelling wave in a coplanar waveguide, the standing wave in an open-circuited microstrip, and a surface mounted device antenna.

Talanov, Vladimir V.; Lettsome, Nesco M., Jr.; Borzenets, Valery; Gagliolo, Nicolas; Cawthorne, Alfred B.; Orozco, Antonio

2014-04-01

267

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.

268

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

269

Comprehensive X-Ray Absorption Models for Oxygen and Neon  

NASA Astrophysics Data System (ADS)

We propose to perform state-of-the-art R-matrix calculations for the oxygen and neon photoabsorption cross sections to improve upon earlier, incomplete data. Several important higher-order effects will be addressed: orbital relaxation, Auger line broadening, two-electron shake, and elimination of pseudoresonances. The computed atomic cross sections will first be fit by a recently-developed analytical fitting formula, and then benchmarked further to experimental and Chandra observed absorption lines. The resulting data will be uploaded into the AtomDB, XSPEC, and ISIS databases for spectral modeling use. These definitive cross sections will resolve an outstanding discrepancy between XSTAR and SPEX spectral modeling predictions of molecular (dust and/or ice) abundances in the ISM.

Gorczyca, Thomas

2013-09-01

270

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

271

Flies, genes, and learning.  

PubMed

Flies can learn. For the past 25 years, researchers have isolated mutants, engineered mutants with transgenes, and tested likely suspect mutants from other screens for learning ability. There have been notable surprises-conventional second messenger systems co-opted for intricate associative learning tasks, two entirely separate forms of long-term memory, a cell-adhesion molecule that is necessary for short-term memory. The most recent surprise is the mechanistic kinship revealed between learning and addictive drug response behaviors in flies. The flow of new insight is likely to quicken with the completion of the fly genome and the arrival of more selective methods of gene expression. PMID:11520934

Waddell, S; Quinn, W G

2001-01-01

272

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

273

Differential gene expression in bacterial symbionts from loliginid squids demonstrates variation between mutualistic and  

E-print Network

and loliginid squids (Mollusca: Cephalopoda). Despite the existence of multiple strain colonization between of the light organs of bobtail squids in the genus Euprymna (Mollusca: Cephalopoda) (Jones and Nishiguchi,

McFall-Ngai, Margaret

274

76 FR 74724 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Amendment 11 AGENCY: National Marine Fisheries...implementing Amendment 11 to the Atlantic Mackerel, Squid, and Butterfish (MSB) Fishery Management Plan (FMP). This final...

2011-12-01

275

77 FR 51853 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 6 and...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 6 AGENCY...species, including Atlantic mackerel, butterfish, Atlantic bluefish, spiny...

2012-08-27

276

77 FR 40527 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the 2012 Trimester 2 Directed Longfin...species managed under the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan (FMP). The procedures for...

2012-07-10

277

76 FR 51272 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the 2011 Trimester 2 Directed Loligo...species managed under the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan (FMP). The procedures for...

2011-08-18

278

75 FR 32745 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Scoping Process AGENCY: National Marine Fisheries...Management Plan (FMP) for Atlantic Mackerel, Squid, and Butterfish (MSB) and to prepare an EIS to analyze the impacts of...

2010-06-09

279

77 FR 67305 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Atlantic Mackerel, Squid, and Butterfish Fisheries; Specifications and...revised 2012 specifications for the butterfish fishery, which is managed as...Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan....

2012-11-09

280

77 FR 23635 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Specifications and Management...the Atlantic Mackerel, Squid, and Butterfish fisheries. DATES: Effective April...interim final rule to implement 2012 butterfish fishery specifications was...

2012-04-20

281

Operation MexFly  

NSDL National Science Digital Library

This activity is an environmental study of the effects of spraying malathion on Mexican fruit flies. In 1990, the city of El Cajon experienced an infestation of Mexican fruit flies, necessitating an aerial spraying of the insecticide malathion. The local community had a varied and wide-spread reaction to the procedure. A colleague and I collaborated to create a series of lessons about the Mexican fruit fly, the insecticide malathion and risk assessment. It was an opportunity to do cross disciplinary teaching, enabling students to see interrelationships between biology, chemistry and local government. The lesson includes background reading for discussion on the Mexican fruit fly, insecticides, and LD-50s. Students complete a short lab on serial dilutions, with risk analysis application problems and a Town Hall meeting to decide if the spraying should take place or develop alternatives.

BEGIN:VCARD VERSION:2.1 FN:Susan E. Emerson N:E. Emerson; Susan ORG:Grossmont High School REV:2005-04-11 END:VCARD

1995-06-30

282

Venus fly trap  

NSDL National Science Digital Library

Time-lapse photos or video show progressions from the start of an event to the end of the event. These time-lapse photos illustrate the growth of a single Venus fly trap. Biological processes require time.

Paul Lenz (None;)

2006-01-26

283

Closed-cycle refrigerator-cooled scanning SQUID microscope for room-temperature samples  

Microsoft Academic Search

We have designed, built, and operated a scanning superconducting quantum interference device (SQUID) microscope that uses a closed-cycle refrigerator to cool a YBa2Cu3O7 (YBCO) dc SQUID to 77 K. The SQUID is mounted in custom vacuum housing that has a thin sapphire window that maintains thermal isolation of the SQUID while allowing samples to be imaged in air at room

E. F. Fleet; S. Chatraphorn; F. C. Wellstood; L. A. Knauss; S. M. Green

2001-01-01

284

Development of advanced SQUID system for nondestructive evaluation of material degradation in power plants  

SciTech Connect

A newer and more advanced version of the SQUID sensor system for estimating the degradation of materials in power plants have been developed. The miniaturized SQUID sensor developed for nondestructive measurement is 262 mm high, 152 mm in diameter, and 5 kg in weight, making it only one-twelfth the size and one-tenth the weight of a conventional SQUID sensor. Tests have demonstrated that the new SQUID sensor can successfully estimate fatigue damage in Type 316 stainless steel.

Otaka, M.; Hayashi, E. [Hitachi, Ltd., Ibaraki (Japan)

1995-08-01

285

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,

286

Ever Fly a Tetrahedron?  

NSDL National Science Digital Library

Few things capture the spirit of spring like flying a kite. Watching a kite dance and sail across a cloud-spotted sky is not only a visually appealing experience, it also provides a foundation for studies in science and mathematics. In this kite-building and flying activity, students use inexpensive and readily-available materials to construct a simple tetrahedron kite, then design an experiment to test how changing one variable in the kite's design affects its performance.

King, Kenneth

2004-03-01

287

LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON  

PubMed Central

Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was approximately as predicted theoretically on the basis of the poorly conducting dielectric characteristics of the membrane previously determined. For the large majority of the axons, the impedance reached a maximum at a low frequency and the reactance then vanished at a frequency between 150 and 300 cycles per second. Below this frequency, the reactance was inductive, reaching a maximum and then approaching zero as the frequency was decreased. The inductive reactance is a property of the axon and requires that it contain an inductive structure. The variation of the impedance with interpolar distance indicates that the inductance is in the membrane. The impedance characteristics of the membrane as calculated from the measured longitudinal impedance of the axon may be expressed by an equivalent membrane circuit containing inductance, capacity, and resistance. For a square centimeter of membrane the capacity of 1 µf with dielectric loss is shunted by the series combination of a resistance of 400 ohms and an inductance of one-fifth henry. PMID:19873252

Cole, Kenneth S.; Baker, Richard F.

1941-01-01

288

SQUID detected NMR in microtesla magnetic fields.  

PubMed

We have built an NMR system that employs a superconducting quantum interference device (SQUID) detector and operates in measurement fields of 2-25 microT. The system uses a pre-polarizing field from 4 to 30 mT generated by simple room-temperature wire-wound coils that are turned off during measurements. The instrument has an open geometry with samples located outside the cryostat at room-temperature. This removes constraints on sample size and allows us to obtain signals from living tissue. We have obtained 1H NMR spectra from a variety of samples including water, mineral oil, and a live frog. We also acquired gradient encoded free induction decay (FID) data from a water-plastic phantom in the microT regime, from which simple projection images were reconstructed. NMR signals from samples inside metallic containers have also been acquired. This is possible because the penetration skin depth is much greater at the low operating frequencies of this system than for conventional systems. Advantages to ultra-low field NMR measurements include lower susceptibility artifacts caused by high strength polarizing and measurement fields, and negligible line width broadening due to measurement field inhomogeneity, reducing the burden of producing highly homogeneous fields. PMID:15324752

Matlachov, Andrei N; Volegov, Petr L; Espy, Michelle A; George, John S; Kraus, Robert H

2004-09-01

289

Upgrade of the neon soft X-ray spectrometer for Alcator C-Mod  

E-print Network

In order to study plasma rotation, temperature, and impurity density, a Neon Soft X-ray Spectrometer (NeSoXs) was installed on the Alcator C-Mod tokamak. This spectrometer used a spherically bent mica crystal as the ...

Podpaly, Yuri Anatoly

2007-01-01

290

The UT 19-channel DC SQUID based neuromagnetometer.  

PubMed

A 19-channel DC SQUID based neuromagnetometer is under construction at the University of Twente (UT). Except for the cryostat all elements of the system are developed at the UT. It comprises 19 wire-wound first-order gradiometers in a hexagonal configuration. The gradiometers are connected to planar DC SQUIDs fabricated with a Nb/Al, AlO kappa/Nb technology. For this connection we developed a method to bond a Nb wire to a Nb thin-film. The SQUIDs are placed in compartmentalised Nb modules. Further, external feedback is incorporated in order to eliminate cross talk between the gradiometers. The electronics basically consist of a phase-locked loop operating with a modulation frequency of 100 kHz. Between SQUID and preamplifier a small transformer is used to limit the noise contribution of the preamplifier. In the paper the overall system is described, and special attention is paid to the SQUID module (bonding, compartments, external-feedback setup, output transformer). PMID:1807878

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

1991-01-01

291

Coupled non-uniform bi-squid: A numerical investigation  

NASA Astrophysics Data System (ADS)

This work investigates through numerical simulations a novel device that improvesdynamic range and linearity. The standard DC SQUID can increase in linearity by adding athird junction, changing to a device known as the bi-SQUID. It is known that the dynamicrange can increase by connecting SQUIDs in series, and it has been shown that nonuniformityin the loops sizes in arrays of SQUIDs can produce a unique 'anti'-peak at thezero magnetic flux (device know as a SQIF). Thus, combining these ideas we can improvethe dynamic range and design a highly linear device with a unique 'anti'-peak. Hence, this device can be referred to as a bi-SQIF or non-uniform bi-SQUID array. Results have shown that the maximum voltage swing increase proportional to N, where N is the number of loops connected in series. The spur free dynamic range also improves as N increases, which is directly related to the linearity of the device. Therefore, we have designed a device which can lead to improvements which can be applicable to low noise amplifier (LNA), and provide a platform for creating "electrically" small antennas.

Longhini, Patrick; Berggren, Susan; Palacios, Antonio; In, Visarath; Leese de Escobar, Anna

2012-06-01

292

NeOn-project.org NeOn: Lifecycle Support for Networked Ontologies  

E-print Network

server and the NeOn toolkit. This integration uses a web service connection from the Alignment server to an OntoLight web service interface. Document Identifier: NEON/2008/D3.3.3/v1.0 Date due: October 31st 38334 Saint-Ismier, France S14DP Sheffield, United Kingdom Contact person: Jérôme Euzenat Contact person

Paris-Sud XI, Université de

293

Intense atomic and molecular beams via neon buffer-gas cooling  

Microsoft Academic Search

We realize a continuous, intense, cold molecular and atomic beam source based on buffer-gas cooling. Hot vapor (up to 600 K) from an oven is mixed with cold (15 K) neon buffer gas, and then emitted into a high-flux beam. The novel use of cold neon as a buffer gas produces a forward velocity distribution and low-energy tail that is

David Patterson; Julia Rasmussen; John M. Doyle

2009-01-01

294

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

295

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

E-print Network

Protein synthesis in a solitary benthic cephalopod, the Southern dumpling squid (Euprymna tasmanica-history Protein synthesis Squid Tissue protein synthesis Rates of protein synthesis were measured in the whole-dose of 3 H phenylalanine for the measurement of protein synthesis with different size squid and to make

McFall-Ngai, Margaret

296

Tenderizing Squid Mantle by Marination at Different pH and Temperature Levels  

Microsoft Academic Search

The very tough muscle tissues of broadtail shortfin squid (Illex coindetii) cause considerable marketing limitations. A tenderizing process involving the activation of squid mantle intramuscular proteases to counteract this problem was investigated. The effects of pH, temperature, and incubation time on the final texture of squid mantle rings were assessed by tensile tests, where strain was measured for given levels

A. Collignan; D. Montet

1998-01-01

297

Sequence and phylogenetic analysis of squid myosin-V: A vesicle motor in nerve cells  

Microsoft Academic Search

We have shown that vesicles in the axoplasm of the squid giant axon move on actin filaments and that movement is inhibited by myosin V-specific antibodies (Tabb et al., 1998). In the study reported in this article, experiments were performed to clone and sequence the cDNA for squid brain myosin V. Five proteolytic fragments of purified squid brain myosin V

Bradley J. Molyneaux; Mary K. Mulcahey; Phillip Stafford; George M. Langford

2000-01-01

298

Can length frequency analysis be used to determine squid growth? – An assessment of ELEFAN  

Microsoft Academic Search

Jackson, G. D., Alford, R. A., and Choat, J. H. 2000. Can length frequency analysis be used to determine squid growth? - An assessment of ELEFAN. - ICES Journal of Marine Science, 57: 948-954. Current scientific literature presents two viewpoints regarding squid growth. One view suggests that squid have long life spans and asymptotic growth. This viewpoint exists primarily as

George D. Jackson; Ross A. Alford; J. Howard Choat

2000-01-01

299

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

300

The squid family Gonatidae plays an important role in the ecosystems  

E-print Network

733 The squid family Gonatidae plays an important role in the ecosystems of the North Pacific. In the Sea of Okhotsk, the annual production of gonatid squids is more than half that of fish production Pacific and the processes influencing the production of gonatid squids in this region, information

301

SCANNING SQUID MICROSCOPY ON IRON PNICTIDE AND TIME-REVERSAL SYMMETRY-BREAKING  

E-print Network

SCANNING SQUID MICROSCOPY ON IRON PNICTIDE AND TIME-REVERSAL SYMMETRY-BREAKING SUPERCONDUCTORS and SQUID sensors used in this work. Chapter 2: We fabricated GaAs/AlxGa1-xAs two-dimensional electron gas generate the internal field. We perform SQUID magnetometry scans of Sr2RuO4 and PrOs4Sb12, and find

Moler, Kathryn A.

302

Gradiometric micro-SQUID susceptometer for scanning measurements of mesoscopic samples  

E-print Network

Gradiometric micro-SQUID susceptometer for scanning measurements of mesoscopic samples Martin E April 2008; published online 28 May 2008 We have fabricated and characterized micro-SQUID susceptometers of the sample; modulation coils to allow setting the SQUID at its optimum bias point independent of the applied

Moler, Kathryn A.

303

Tunable Electrodynamic Environment and Coulomb Blockade with 1D SQUID Arrays  

E-print Network

Tunable Electrodynamic Environment and Coulomb Blockade with 1D SQUID Arrays D. B. Haviland, M arrays of small capacitance SQUIDs have been used to make a tunable elec­ trodynamic environment for a single, small capac­ itance Josephson junctions. The tunability of the SQUID arrays when used

Haviland, David

304

TUNABLE ELECTRODYNAMIC ENVIRONMENT AND COULOMB BLOCKADE WITH 1D SQUID ARRAYS  

E-print Network

TUNABLE ELECTRODYNAMIC ENVIRONMENT AND COULOMB BLOCKADE WITH 1D SQUID ARRAYS M. WATANABE RIKEN, 2 of small-capacitance SQUIDs have been used to make a tunable electrodynamic environment for a single, small-capacitance Josephson junction. The tunability of the SQUID arrays when used in the measurement leads allows us

Haviland, David

305

SQUID rings as macroscopic quantum objects: The quantum-classical interface  

SciTech Connect

We consider the interaction of a SQUID ring in the ultra small capacitance quantum limit. We show that the energy level structure of such a SQUID ring, arising from its quantum mechanical behaviour, leads to a novel spectroscopy. We give examples of the way in which this spectroscopy is made manifest through the interation of SQUID ring with a classical circuit apparatus. (AIP)

Prance, R.J.; Whiteman, R.; Prance, H.; Clark, T.D.; Diggins, J.; Ralph, J.F.; Spiller, T.P.; Clippingdale, A. [Physics Department, University of Sussex, Brighton, Sussex, BN1 9QH (United Kingdom); Widom, A.; Srivastava, Y. [Physics Department, Northeastern University, Boston, Massachusetts 02115 (United States)

1996-05-01

306

SCANNING SQUID MICROSCOPY ON IRON PNICTIDE AND TIME-REVERSAL SYMMETRY-BREAKING  

E-print Network

SCANNING SQUID MICROSCOPY ON IRON PNICTIDE AND TIME-REVERSAL SYMMETRY-BREAKING SUPERCONDUCTORS;Abstract Chapter 1 briefly describes the scanning probe microscope system and SQUID sensors used field. We perform SQUID magnetometry scans of Sr2RuO4 and PrOs4Sb12, and find no superconductivity

Moler, Kathryn A.

307

Low field DC SQUID nuclear magnetic resonance on single crystal UPt3  

E-print Network

Low field DC SQUID nuclear magnetic resonance on single crystal UPt3 R. Koorber a,*, A. Casey a , B, Abbestrasse 2-12, D-10587 Berlin, Germany c Northwestern University, Evanston, IL 60208, USA Abstract A SQUID pulsed NMR on 195 Pt. The system uses a multiloop DC SQUID with additional positive feedback and operates

Le Roy, Robert J.

308

MFR PAPER 128C Strandings of Shortfin Squid, II/ex  

E-print Network

MFR PAPER 128C Strandings of Shortfin Squid, II/ex illecebrosus, in New England in Fall 1976 F. E 02642. Figure (.-Shore area of grealest strandings (shaded) of shon fin squid in Cape Cod Bay during fall 1976, and numbers of this squid caught per h-hour low at otter trawl stations in fall I975

309

27 SQUID amplifier operating with high-Q resonant input load Paolo Falferia  

E-print Network

27 SQUID amplifier operating with high-Q resonant input load Paolo Falferia and Michele Bonaldi characterization of a low-noise two-stage superconducting quantum interference device SQUID amplifier developed. To evaluate the back action voltage noise, the SQUID is strongly coupled to a high-Q macroscopic electrical

310

Reference: Bid. Bull. 192: 364-374. (June. 1997) Laboratory Culture of the Sepiolid Squid  

E-print Network

Reference: Bid. Bull. 192: 364-374. (June. 1997) Laboratory Culture of the Sepiolid Squid Eupvymna, was cultured through one complete life cycle in 4 months. Paralarval squid hatchlings were actively planktonic and diurnal quiescence. Squids were aggressive predators that preferred actively swimming prey up to 2- 4

Ruby, Edward G.

311

Jumbo squid beaks: Inspiration for design of robust organic composites Ali Miserez a  

E-print Network

Jumbo squid beaks: Inspiration for design of robust organic composites Ali Miserez a , Youli Li b of the jumbo squid (Dosidicus gigas). Its main constituents are chitin fibers (15­20 wt.%) and histidine of the present article is on another hard but unmineralized biomolecular material: the beaks of the jumbo squid

Zok, Frank

312

Digestive efficiency and dry-matter digestibility in Steller sea lions fed herring, pollock, squid, and  

E-print Network

Digestive efficiency and dry-matter digestibility in Steller sea lions fed herring, pollock, squid of a single species: herring, pollock, and squid. Two of the animals were also fed pink salmon. Dry), pollock: 93.9 ± 1.4%, salmon: 93.4 ± 0.5%, squid: 90.4 ± 1.3%). Steller sea lions appear to digest prey

313

Motion detection of a micromechanical resonator embedded in a d.c. SQUID  

E-print Network

LETTERS Motion detection of a micromechanical resonator embedded in a d.c. SQUID S. ETAKI1,2 *, M.s.j.vanderzant@tudelft.nl Published online: 31 August 2008; doi:10.1038/nphys1057 Superconducting quantum interference devices (SQUIDs into SQUIDs to achieve controlled entanglement of the resonator ground state and a qubit3 as well

Loss, Daniel

314

ELIZABETH H. AMARAL and H. ARNOLD CARR Experimental Fishing for Squid  

E-print Network

ELIZABETH H. AMARAL and H. ARNOLD CARR Experimental Fishing for Squid With Lights in Nantucket Sound Nantucket Sound squid survey areas. Elizabeth H. Amaral and H. Arnold Carr consecutive years and has caught squid in them each year. He first be- came interested in this type of project

315

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

E-print Network

The Quality of Squid Held in Chilled Seawater Versus Conventional Shipboard Handling VINCENT G. AMPOLA liest tow of each trip were always placed in Pen A, and the squid/ice/ seawater ratio was adjusted provided a workable slush into which the freshly caught squid were submerged. During each trip, the top

316

FOUR NEW SPECIES OF SQUID (OEGOPSIDA: ENOPLOTEUTHIS) FROM THE CENTRAL PACIFIC AND A DESCRIPTION OF ADULT  

E-print Network

FOUR NEW SPECIES OF SQUID (OEGOPSIDA: ENOPLOTEUTHIS) FROM THE CENTRAL PACIFIC AND A DESCRIPTION enoplo- teuthid squids are deepwater animals that are not easily accessible or profitableto fish, they are not at present generally exploited commercially. In Toyama Bay, Sea of Japan, however, the enoploteuthid squid

317

Ontogenetic Changes in Mantle Kinematics During Escape-Jet Locomotion in the Oval Squid,  

E-print Network

Ontogenetic Changes in Mantle Kinematics During Escape-Jet Locomotion in the Oval Squid of Sepioteuthis lessoniana, the oval squid. Changes in mantle diameter during the jet were measured from digi mantle diameter) during an escape jet was significantly greater in hatchlings than in older, larger squid

Kier, William M.

318

Squid Catches Resulting From Trawl Surveys off the Southeastern United States  

E-print Network

Squid Catches Resulting From Trawl Surveys off the Southeastern United States J. DAVID WHITAKER Introduction The importance of the squid fishery off the northeastern United States has grown considerably since 1964 with re- cent squid catches by foreign fleets av- eraging 50,000 t (110,231 ,000 pounds

319

NMR/MRI with hyperpolarized gas and high Tc SQUID  

DOEpatents

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

Schlenga, Klaus (Eggenstein, DE); de Souza, Ricardo E. (Recife, BR); Wong-Foy, Annjoe (Berkeley, CA); Clarke, John (Berkeley, CA); Pines, Alexander (Berkeley, CA)

2000-01-01

320

nSQUID arrays as conveyers of quantum information  

NASA Astrophysics Data System (ADS)

We have considered the quantum dynamics of an array of nSQUIDs—two-junction SQUIDs with negative mutual inductance between their two arms. Effective dual-rail structure of the array creates additional internal degree of freedom for the fluxons in the array, which can be used to encode and transport quantum information. Physically, this degree of freedom is represented by electromagnetic excitations localized on the fluxon. We have calculated the spatial profile and frequency spectrum of these excitations. Their dynamics can be reduced to two quantum states, so that each fluxon moving through the array carries with it a qubit of information. Coherence properties of such a propagating qubit in the nSQUID array are characterized by the dynamic suppression of the low-frequency decoherence due to the motion-induced spreading of the noise spectral density to a larger frequency interval.

Deng, Qiang; Averin, D. V.

2014-12-01

321

Microwave SQUID Multiplexer for the Readout of Metallic Magnetic Calorimeters  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

322

Imaging radio-frequency fields using a scanning SQUID microscope  

SciTech Connect

Using a liquid-nitrogen-cooled scanning SQUID magnetic microscope, we have developed a technique for broadband imaging of radio-frequency (rf) and microwave fields with a spatial resolution of about 15 [mu]m. We have produced images of the amplitude of 50 MHz fields with an rms noise of 2.6 nT and a 300 [mu]m/s scan rate. Detection is accomplished by using the nonlinearity of the voltage-flux characteristic of the SQUID to rectify the rf fields. Our present technique is limited by cavity mode resonances in the SrTiO[sub 3] substrate of our SQUID sensor. Using a small excitation probe, we have directly imaged these resonances at frequencies up to about 12.5 GHz.

Black, R.C.; Wellstood, F.C. (Center for Superconductivity Research, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)); Dantsker, E.; Miklich, A.H.; Koelle, D.; Ludwig, F.; Clarke, J. (Department of Physics, University of California and Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

1995-03-06

323

Signal detection in l/f noise of SQUID magnetometers  

NASA Technical Reports Server (NTRS)

It is shown that the variance on the SQUID power spectrum in the l/f low frequency region is well behaved, i.e., any small frequency band may be treated as white noise in standard power spectrum estimation theory. Specifically a calibration signal is examined at 0.017 Hz with an equivalent energy referred to the SQUID input coil of 1 times 10 to the -30th J and a digitally recorded and analyzed record of 140 hr duration obtained an optimum S/N better than 400. The results are in good agreement with theory. In addition no deviation from the l/f dependence of the noise energy spectrum is seen down to frequencies below 10 to the -5th Hz. A commercially available SQUID and electronics system were used.

Cabrera, B.; Anderson, J. T.

1978-01-01

324

A modular low noise 7-channel SQUID-magnetometer  

SciTech Connect

This paper reports on a modular low noise 7-channel SQUID-magnetometer for biomagnetic measurements. The DC-SQUIDs are prepared by thin film technology based on the materials NbN-MgO-NbN and show a flux noise below 10{mu}{phi}{sub 0}/square root of Hz. The signal is picked up with first order wirewound gradiometers of 2cm diameter and coupled to the SQUIDs by integrated coupling coils. Individual channels can be replaced from the system and various gradiometers can be used giving a flexible modular system. The electronics are based on the flux locked loop method extended by a new bias modulation technique to reduce 1/f noise. The overall system noise is below 20 ft. square root Hz. Biomagnetic measurements on auditory evoked fields have been carried out.

Dossel, O.; David, B.; Fuchs, M.; Kullmann, W.H.; Ludeke, K.M. (Philips GmbH, Forshchungslaboratorium Hamburg, Postfach 54 08 40, 2000 Hamburg 54 (DE))

1991-03-01

325

A three channel SQUID-system using a multiplexed readout  

SciTech Connect

This paper reports on conventional multichannel SQUID systems which require a number of wires connecting the individual SQUIDs and feedback coils to the room temperature electronics. In order to reduce the heat transport by these wires and to avoid the accompanied increased helium losses, we studied the possibility of using a multiplexed readout, requiring only a fraction of feed lines than needed by conventional systems. The authors used rf-SQUIDs in our experiments to avoid additional wires for dc-bias currents. A bias frequency of 100 MHz was chosen to achieve a sufficiently low flux-noise. The influence of modulation frequency and multiplexing frequency on the stability of the flux-locked loop and on the slew rate of the system was studied in some detail.

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

1991-03-01

326

Improved Readout Scheme for SQUID-Based Thermometry  

NASA Technical Reports Server (NTRS)

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

Penanen, Konstantin

2007-01-01

327

Analysis of a dc SQUID readout scheme with voltage feedback circuit and low-noise preamplifier  

NASA Astrophysics Data System (ADS)

We analyzed the dc SQUID with voltage feedback circuit (VFC) and a low-noise room-temperature preamplifier to evaluate the feasibility of a low-noise SQUID direct-coupled readout scheme (DRS), possibly eliminating the need for a two-stage scheme employing a SQUID preamplifier. The passive VFC, connected in parallel to the SQUID, consists of a resistor Rs in series with an inductor L s. This inductor is coupled to the SQUID by a mutual inductance Ms. The purpose of the VFC is to increase the SQUID’s flux-to-voltage transfer coefficient ?V/??, thus reducing the preamplifier noise contribution ??preamp. However, at the same time, VFC introduces the thermal noise of Rs, ??R, which may not be negligible. Generally, the noise of the readout scheme, ??readout, may thus include both ??preamp and ??R, i.e., ??readout2 = ??preamp2 + ??R2. To characterize the SQUID operation with VFC we introduced two dimensionless parameters, r = Rs/Rd and ? = (M s/Mdyn) - (Rs/R d), where Rd and Mdyn = 1/(?i/??) are dynamic properties of the SQUID itself. For assumed intrinsic SQUID parameters, we then numerically analyzed the dependence of ??readout noise components on r and ? to determine their suitable ranges and the minimum of ??readout. To verify our analysis, we experimentally characterized, in liquid helium, three niobium SQUIDs with VFC, having suitably chosen r and ?. The measured SQUID system flux noise was on the order of 1 ??0/?Hz, comparable to the intrinsic noise of the SQUID itself. The deduced equivalent voltage noise was comparable to that of a SQUID preamplifier in the two-stage readout. Simple single-stage ultra-low-noise SQUID DRS readout was thus demonstrated.

Zeng, Jia; Zhang, Yi; Schmelz, Matthias; Mück, Michael; Krause, Hans-Joachim; Braginski, Alex I.; Lee, Yong-Ho; Stolz, Ronny; Kong, Xiangyan; Xie, Xiaoming; Meyer, Hans-Georg; Offenhäusser, Andreas; Jiang, Mianheng

2014-08-01

328

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. PMID:818340

1976-01-01

329

Effects of Storage Temperature on the Quality of Frozen Squid  

NASA Astrophysics Data System (ADS)

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

Kozima, Tsuneo; Ohtaka, Tateo

330

Multiloop integrated dc SQUID low noise RF amplifier  

NASA Astrophysics Data System (ADS)

A new type of multiloop dc SQUID in the form of a second order gradiometer with integrated input coil and extremely low stray capacitances was designed to improve SQUID amplifier parameters. For decreasing the loop inductance four partial loops were connected in parallel. Single input turns placed inside each loop were connected in series to increase the input coil inductance for better impedance matching. The amplifier noise temperature lower than 0.5 K and power gain nearly 20 dB were measured at 430 MHz for 60 MHz bandwidth in the case of tuned amplifier.

Tarasov, Michael; Prokopenko, George; Belitsky, Victor; Filippenko, Ludmila

331

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

332

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); Pines, Alexander (Berkeley, CA); McDermott, Robert F. (Monona, WI); Trabesinger, Andreas H. (London, GB)

2008-12-16

333

Polarization rotation by an rf-SQUID metasurface  

E-print Network

We study the transmission and reflection of a plane electromagnetic wave through a two dimensional array of rf-SQUIDs. The basic equations describing the amplitudes of the magnetic field and current in the split-ring resonators are developed. These yield in the linear approximation the reflection and transmission coefficients. The polarization of the reflected wave is independent of the frequency of the incident wave and of its polarization; it is defined only by the orientation of the split-ring. The reflection and transmission coefficients have a strong resonance that is determined by the parameters of the rf-SQUID; its strength depends essentially on the incident angle.

Caputo, J -G; Maimistov, A I

2015-01-01

334

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

335

SQUID-based Resonant Detection of Axion Dark Matter  

E-print Network

A new method for searching for Dark Matter axions is proposed. It is shown that a two-contact SQUID can detect oscillating magnetic perturbations induced by the axions in a strong inhomogeneous magnetic field. A resonant signal is a steplike response in the SQUID current-voltage characteristic at a voltage corresponding to the axion mass with a height depending on the axion energy density near the Earth. The proposed experimental technique appears to be sensitive to the axions with masses $m_a\\lesssim 10^{-4}$ eV, which is well-motivated by current researches both in cosmology and in particle physics.

Vladimir Popov

2014-10-24

336

A review of SQUID magnetometry applied to nondestructive evaluation  

SciTech Connect

This paper reports on the development of the SQUID as the most sensitive instrument known for the measurement of changes in magnetic flux has presented new opportunities for its use for nondestructive evaluation (NDE) of electrically conducting and ferromagnetic structures. This presentation will review the preliminary studies of this application within the past few years in order to serve as an introduction to those that follow. It will include early work by the author which explored the ability of a SQUID to detect defects in a buried pipe and to detect fatigue in steel structures.

Weinstock, H. (Air Force Office of Scientific Research, Bolling AFB, DC (United States))

1991-03-01

337

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

338

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

339

Scanning high-Tc SQUID imaging system for magnetocardiography  

NASA Astrophysics Data System (ADS)

A scanning magnetocardiography (MCG) system constructed from SQUID sensors offers potential to basic or clinical research in biomagnetism. In this work, we study a first order scanning electronic high-Tc (HTS) SQUID MCG system for biomagnetic signals. The scanning MCG system was equipped with an x-y translation bed powered by step motors. Using noise cancellation and ?-metal shielding, we reduced the noise level substantially. The established scanning HTS MCG system was used to study the magnetophysiology of hypercholesterolaemic (HC) rabbits. The MCG data of HC rabbits were analysed. The MCG contour map of HC rabbits provides experimental models for the interpretation of human cardiac patterns.

Yang, Hong-Chang; Wu, Tsung-Yeh; Horng, Herng-Er; Wu, Chau-Chung; Yang, S. Y.; Liao, Shu-Hsien; Wu, Chiu-Hsien; Jeng, J. T.; Chen, J. C.; Chen, Kuen-Lin; Chen, M. J.

2006-05-01

340

Two methods for a first order hardware gradiometer using two HTS SQUIDs  

SciTech Connect

Two different systems for noise cancellation (first order gradiometers) have been developed using two similar high temperature superconducting (HTS) SQUIDs. Analog gradiometry is accomplished in hardware by either (1) subtracting the signals from the sensor and background SQUIDs at a summing amplifier (parallel technique) or (2) converting the inverted background SQUID signal to a magnetic field at the sensor SQUID (series technique). Balance levels achieved are 2000 and 1000 at 20 Hz for the parallel and series methods respectively. The balance level as a function of frequency is also presented. The effect which time delays in the two sets of SQUID electronics have on this balance level is presented and discussed.

Espy, M.A.; Flynn, E.R.; Kraus, R.H. Jr.; Matlachov, A.

1998-12-31

341

Hysteresis and intermittency in a nano-bridge based suspended DC-SQUID  

E-print Network

We study voltage response of nano-bridge based DC-SQUID fabricated on a Si\\_{3}N\\_{4} membrane. Such a configuration may help in reducing 1/f noise, which originates from substrate fluctuating defects. We find that the poor thermal coupling between the DC-SQUID and the substrate leads to strong hysteretic response of the SQUID, even though it is biased by an alternating current. In addition, when the DC-SQUID is biased near a threshold of spontaneous oscillations, the measured voltage has an intermittent pattern, which depends on the applied magnetic flux through the SQUID.

Segev, Eran; Shtempluck, Oleg; Xue, Fei; Buks, Eyal

2010-01-01

342

Hysteresis and intermittency in a nano-bridge based suspended DC-SQUID  

E-print Network

We study voltage response of nano-bridge based DC-SQUID fabricated on a Si\\_{3}N\\_{4} membrane. Such a configuration may help in reducing 1/f noise, which originates from substrate fluctuating defects. We find that the poor thermal coupling between the DC-SQUID and the substrate leads to strong hysteretic response of the SQUID, even though it is biased by an alternating current. In addition, when the DC-SQUID is biased near a threshold of spontaneous oscillations, the measured voltage has an intermittent pattern, which depends on the applied magnetic flux through the SQUID.

Eran Segev; Oren Suchoi; Oleg Shtempluck; Fei Xue; Eyal Buks

2010-10-21

343

TerraFly  

NSDL National Science Digital Library

Associated with the School of Computer Science at Florida International University, the High Performance Database Research Center (HPDRC) released TerraFly in November 2001, a Web-based application that allows users to view Geographic Information Systems (GIS) images. In agreement with TerraFly, the United States Geological Survey (USGS) provides the project with many of its satellite images in exchange for a public service: free Web-based access to its application. Through a rather sophisticated Java applet, users have a bird's eye view of the images, much like other Internet services have provided in the past, such as TerraServer (last reviewed in the June 28, 1998 Scout Report). TerraFly, though, improves the still picture delivery of these services by enabling users to view the images continuously and seamlessly, giving the user a feeling of "flying over" the photographed land areas. Different resolutions are available, and the interface is extremely slick though somewhat complicated initially. Users of low bandwidth or active memory should be wary; the applet demands a lot from your computer. Also, even though access to the Web-based application is free through the USGS agreement, users should be aware that the TerraFly Project seems to have mostly commercial motivations. Note: This reviewer had difficulty using Terrafly with Mac Netscape 4.7; however, Mac Internet Explorer functioned properly. This site is also reviewed in the April 5, 2002 NSDL Physical Sciences Report.

2001-01-01

344

NMR of room temperature samples with a flux-locked dc SQUID  

SciTech Connect

Superconducting quantum interference devices (SQUID`s) are the most sensitive detectors of magnetic fields. Since SQUID`s detect the magnetic flux rather than its rate of change, they can be used to great advantage to measure nuclear magnetic resonance (NMR) signals at low fields and frequencies. The authors have used a dc (direct-current) SQUID operated in flux-locked mode to significantly improve upon the previous low-field NMR results performed using an RF (radio-frequency) SQUID. The increase in sensitivity gained by using the dc SQUID has helped in reducing the signal acquisition time by a factor of more than 100 compared with the earlier measurements using an RF SQUID. The authors have also obtained a simple one-dimensional T{sub 1}-contrasted NMR image of a two-component sample consisting of mineral oil and tap water at room temperature. The results highlight the sensitivity of the SQUID as an NMR detector and the promise of using SQUID`s in NMR imaging at low fields for both medical applications and for materials` nondestructive evaluation.

Kumar, S.; Avrin, W.F.; Whitecotton, B.R. [Quantum Magnetics, Inc., San Diego, CA (United States)] [Quantum Magnetics, Inc., San Diego, CA (United States)

1996-11-01

345

Development of nano and micro SQUIDs based on Al tunnel junctions  

NASA Astrophysics Data System (ADS)

Superconducting quantum interference devices (SQUIDs) with nano (micro)-meter dimensions are called nano (micro)-SQUIDs. The high sensitivity for flux and position of nano (micro)-SQUIDs can be applied to detect local magnetic fields induced by vortices and the magnetization of mesoscopic superconductors. Nano-SQUIDs based on carbon-nanotube junctions and niobium weak junctions are well known. However, such nano-SQUIDs are not suitable for large-scale integrated circuits and mass production. Therefore, we employ a combination of lithography using the Niemeyer-Dolan technique and the inductively coupled plasma reactive-ion etching technique to fabricate nano-SQUIDs. Here, we report the fabrication of nano (micro)-SQUIDs based on superconducting aluminum tunnel junctions and their application for vortex formation into mesoscopic chiral superconducting Sr2RuO4[1-3].

Ishiguro, Ryosuke; Watanabe, Eiichiro; Sakuma, Daisuke; Shinozaki, Tomoya; Tsuchiya, Shogo; Nago, Yusuke; Osato, Hirotaka; Tsuya, Daiju; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Nomura, Shintaro; Takayanagi, Hideaki; Maeno, Yoshiteru

2014-12-01

346

Numerical Simulation of SQUID Magnetometer Considering Equivalent Electrical Circuit of Josephson Junction  

NASA Astrophysics Data System (ADS)

A SQUID is a highly sensitive magnetic sensor. However, a defect of SQUID is high susceptibility to magnetic noise. The high robustness of SQUID with respect to magnetic noise enables to widen the range of applications. We have striven to clarify the mechanism of weakness in magnetic noise by means of numerical electromagnetic field simulation to support a SQUID development. However, a Josephson junction was modeled as a constant resistance and a SQUID behaviour was not correctly simulated in the previous paper. Therefore, the non-linear current-voltage characteristic of the Josephson junction is newly taken into account the simulation to represent the SQUID behaviour. As the results, the phenomena of the step-increasing magnetic flux and the spike voltage that could not be reproduced in the previous paper is simulated. It is successful to qualitatively evaluate the SQUID behaviour, i.e. it becomes possible to represent superconducting-to-voltage and voltage-to-superconducting state transitions.

Terauchi, Naoya; Noguchi, So; Igarashi, Hajime

347

Compton profile of neon: Experimental study beyond the impulse approximation  

SciTech Connect

High-precision relative energy-loss spectra of 25 keV electrons scattered from neon atoms are measured in the momentum transfer range 0.5 a.u.

Lahmam-Bennani, A.; Duguet, A.; Rouault, M.

1983-02-15

348

Time delays for attosecond streaking in photoionization of neon  

NASA Astrophysics Data System (ADS)

We revisit the time-resolved photoemission in neon atoms as probed by attosecond streaking. We calculate streaking time shifts for the emission of 2p and 2s electrons and compare the relative delay as measured in a recent experiment by Schultze et al. [Science 328, 1658 (2010), 10.1126/science.1189401]. The B-spline R-matrix method is employed to calculate accurate Eisenbud-Wigner-Smith time delays from multielectron dipole transition matrix elements for photoionization. The additional laser field-induced time shifts in the exit channel are obtained from separate, time-dependent simulations of a full streaking process by solving the time-dependent Schrödinger equation on the single-active-electron level. The resulting accurate total relative streaking time shifts between 2s and 2p emission lie well below the experimental data. We identify the presence of unresolved shake-up satellites in the experiment as a potential source of error in the determination of streaking time shifts.

Feist, Johannes; Zatsarinny, Oleg; Nagele, Stefan; Pazourek, Renate; Burgdörfer, Joachim; Guan, Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

2014-03-01

349

Quantum scattering of neon from a nanotextured surface.  

PubMed

Phonon exchange is the usual cause of decoherence in atom-surface scattering. By including quantum effects in the treatment of Debye-Waller scattering, we show that phonon exchange becomes ineffective when the relevant phonon frequencies are high. The result explains the surprising observation of strong elastic scattering of Ne from a Cu(100) surface nanotextured with a c(2 × 2) Li adsorbate structure. We extend a previous model to describe the phonon spectra by an Einstein oscillator component with an admixture of a Debye spectrum. The Einstein oscillator represents the dominant, high frequency vibration of the adsorbate, normal to the surface, while the Debye spectrum represents the substrate contribution. Neon scattering is so slow that exciting the adsorbate mode has a low probability and is impossible if the incident energy is below the threshold. Thus, adsorbate vibrations are averaged out. A theoretical discussion and calculation shows that under such circumstances the vibrations of a light adsorbate do not contribute to the Debye-Waller effect, with the result that Ne scattering at thermal energies is quantum mechanical and largely elastic, explaining the high reflectivity and the diffraction peaks observed experimentally. PMID:21715773

Levi, A C; Huang, C; Allison, W; Maclaren, D A

2009-06-01

350

Neutrino oscillation signatures of oxygen-neon-magnesium supernovae  

E-print Network

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 ~ 150 ms), the survival probability of electron neutrinos is about 0.68, in contrast to values of 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_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.

C. Lunardini; B. Mueller; H. -Th. Janka

2007-12-18

351

Interstellar oxygen, nitrogen and neon in the heliosphere  

NASA Technical Reports Server (NTRS)

Oxygen, nitrogen and neon pick-up ions of interstellar origin were detected for the first time with the Solar Wind Ion Spectrometer (SWICS) on board Ulysses. The interstellar origin of these ions is established by the following criteria: (a) they are singly charged, (b) they have the broad velocity distributions characteristic of pick-up ions, with an upper limit of twice the solar wind speed, (c) their relative abundance as a function of distance from the sun corresponds to the theoretical expectation, and (d) there is no relation to a planetary or cometary source. The interstellar abundance ratios He(+)/O(+), N(+)/O(+), Ne(+)/O(+) were investigated. At approximately 5.25 AU in the outermost part of Ulysses' trajectory He(+)/O(+) = 175(sup +70 sub -50) N(+)/O(+) = 0.13(sup +0.05 sub -0.05) and Ne(+)/O(+) = 0.18(sup +0.10 sub -0.07) were determined. For the interstellar gas passing through the termination region and entering the heliosphere (He/O)(sub 0) = 290(sup +190 sub -100), (N/O)(sub 0) = 0.13(sup +0.06 sub -0.06) and (Ne/O)(sub 0) = 0.20(sup +0.12 sub -0.09) were obtained from the pick-up ion measurements. Upper limits for the relative abundances of C(+) and C were also determined.

Geiss, J.; Gloeckler, G.; Mall, U.; Von Steiger, R.; Galvin, A. B.; Ogilvie, K. W.

1994-01-01

352

Fly ash collection  

SciTech Connect

To a coal-fired furnace that uses electrostatic precipitation or a mechanical collector to collect fly ash, a mix of magnesia-alumina or magnesia-talc is added above the fireball (2600*-3300* F.). The additive increases the mean particle size of the fly ash and reduces its surface resistivity, thereby causing improved collection in the electrostatic precipitators or mechanical collector. Fine particulates containing heavy metals tend to be agglomerated; thus the invention permits recovery of substantial amounts of heavy metal contaminants that would otherwise be lost as stack emission.

Bain, D.I.; Carter, D.A.; Dixit, S.N.

1981-03-17

353

Interactive Fly: Maternally transcribed genes  

NSDL National Science Digital Library

The maternally transcribed genes section of the award-winning and comprehensive site: Interactive fly. It thoroughly discusses genes, tissues, biochemical paths, and developmental processes in the fruit fly, Drosophila.

PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

2006-11-13

354

Neritic squid resources and cuttlefish resources in Japan  

Microsoft Academic Search

Knowledge concerning biology of two loliginids and three sepiids which are found in the Japanese waters was reviewed including unpublished information of the authors.The swordtip squid, Photololigo edulis, is one of the most important resources for the coastal fisheries of Kyushu and the prefectures facing the southwest Japan Sea. This species is the only species of genus Photololigo found along

Yutaka Natsukari; Masatoki Tashiro

1991-01-01

355

Vampire squid: detritivores in the oxygen minimum zone  

PubMed Central

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

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

2012-01-01

356

A review of SQUID magnetometry applied to nondestructive evaluation  

Microsoft Academic Search

The development of the SQUID as the most sensitive instrument known for the measurement of changes in magnetic flux has presented new opportunities for its use for nondestructive evaluation (NDE) of electrically conducting and ferromagnetic structures. The preliminary studies of this application within the past few years are reviewed in order to serve as an introduction to those that follow.

Harold Weinstock; Bolling AFB

1991-01-01

357

Vampire squid: detritivores in the oxygen minimum zone.  

PubMed

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

Hoving, Hendrik J T; Robison, Bruce H

2012-11-22

358

Abstract--Three experiments were performed in an estuarine squid-  

E-print Network

increased and physical bycatch reduction devices (BRDs) were placed in codends. These modifications aimed). Experiments in gear configuration to reduce bycatch in an estuarine squid-trawl fishery James P. Scandol, Australia The incidental catch of nontarget organisms (termed "bycatch") by com- mercial fishing gears

359

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

360

SQUID amplifiers for infrared detectors and other applications  

SciTech Connect

The advantages of superconducting processing circuitry for focal plane arrays include low power consumption and the possibility of integrating processing circuitry and detectors on the same substrate. The latter configuration allows for reduction in the number of leads to the readout system and therefore removes a significant bottle neck to processing the massive quantities of data coming from large IR FPAs. All signal processing steps may be executed with superconducting circuit elements. Amplification in superconducting circuitry is performed with the SQUID (Superconducting Quantum Interference Device) amplifier. The present phase I SBIR is being used to investigate a scheme for multiplexing many inputs into one SQUID amplifier. This will reduce the number of SQUID amplifiers needed which is a significant improvement because typical high-gain, multiturn-input SQUIDs are the largest element of superconductivity circuitry. The anticipated payoff of this research is in shrinking the size needed for superconducting circuitry that will be integrated onto IR FPA's. In addition, this method should add very little or no noise to the intrinsic detector noise, thus avoiding any degradation in sensitivity when individual detectors are integrated into the array.

Osterman, D.

1990-12-14

361

SQUID-based instrumentation for ultra-low-field MRI  

E-print Network

Magnetic resonance imaging at ultra-low fields (ULF MRI) is a promising new imaging method that uses SQUID sensors to measure the spatially encoded precession of pre-polarized nuclear spin populations at a microtesla-range measurement field. In this work, design and performance of a seven-channel SQUID system for simultaneous 3D ULF MRI and MEG are described. The system consists of seven axial second-order SQUID gradiometers, characterized by magnetic field resolutions of 1.2 - 2.8 fT/rtHz. It also includes five sets of coils for 3D Fourier imaging with pre-polarization. Design components used for rapid switching of the pre-polarizing field and for protecting the SQUIDs from the pre-polarizing pulses are discussed. The system's performance is demonstrated by multi-channel 3D images of a preserved sheep brain acquired at 46 microtesla measurement field with 2.5 mm x 2.5 mm x 5 mm imaging resolution. The ULF MRI images exhibit greater contrast than images of the same brain obtained using conventional high-field...

Zotev, V S; Matlashov, A N; Urbaitis, A V; Kraus, R H

2007-01-01

362

Single channel recordings of K+ currents in squid axons  

Microsoft Academic Search

Ionic currents from individual K+ channels in squid axon membrane have been recorded. At hyperpolarizing membrane voltages, unit events occur as widely spaced rectangular pulses with short interruptions. The frequency of occurrence of the units increases strongly when the membrane is depolarized.

Franco Conti; Erwin Neher

1980-01-01

363

A YBCO RF-SQUID magnetometer and its applications  

NASA Technical Reports Server (NTRS)

An applicable RF-superconducting quantum interference detector (SQUID) magnetometer was made using a bulk sintered yttrium barium copper oxide (YBCO). The temperature range of the magnetometer is 77 to 300 K and the field range 0 to 0.1T. At 77 K, the equivalent flux noise of the SQUID is 5 x 10 to minus 4 power theta sub o/square root of Hz at the frequency range of 20 to 200 Hz. The experiments show that the SQUID noise at low-frequency end is mainly from 1/f noise. A coil test shows that the magnetic moment sensitivity delta m is 10 to the minus 6th power emu. The RF-SQUID is shielded in a YBCO cylinder with a shielding ability B sub in/B sub ex of about 10 to the minus 6th power when external dc magnetic field is about a few Oe. The magnetometer is successfully used in characterizing superconducting thin films.

Luwei, Zhou; Jingwu, Qiu; Xienfeng, Zhang; Zhiming, Tank; Yongjia, Qian

1990-01-01

364

Isolation and Ultrastructural Characterization of Squid Synaptic Vesicles  

PubMed Central

Synaptic vesicles contain a variety of proteins and lipids that mediate fusion with the pre-synaptic membrane. Although the structures of many synaptic vesicle proteins are known, an overall picture of how they are organized at the vesicle surface is lacking. In this paper, we describe a better method for the isolation of squid synaptic vesicles, and characterize the results. For highly pure and intact synaptic vesicles from squid optic lobe, glycerol density gradient centrifugation was the key step. Different electron microscopic methods show that vesicle membrane surfaces are largely covered with structures corresponding to surface proteins. Each vesicle contains several stalked globular structures extending from the vesicle surface that are consistent with the V-ATPase. BLAST search of a squid EST library identifies 10 V-ATPase subunits, which are expressed in the squid stellate ganglia. Negative stain tomography demonstrates directly that vesicles flatten during the drying step of negative staining, and furthermore shows details of individual vesicles and other proteins at the vesicle surface. PMID:21551445

Pekkurnaz, Gulcin; Fera, Andrea; Zimmerberg-Helms, Jessica; DeGiorgis, Joseph A.; Bezrukov, Ludmila; Blank, Paul S.; Mazar, Julia; Reese, Thomas S.; Zimmerberg, Joshua

2013-01-01

365

Kendall Hunt Dissection of a Squid: Part 2  

NSDL National Science Digital Library

The purpose of this 9-minute video is to illustrate notable anatomical structures of the market squid (Loligo opalescens) to prepare teachers to lead a dissection of this species; however, this video is not meant to be viewed by students. Presented as a workshop at the NMEA Annual Conference, July 2010.

2012-01-01

366

SQUID gradiometry for magnetocardiography using different noise cancellation techniques  

Microsoft Academic Search

Magnetocardiographic (MCG) measurements in unshielded environment require efficient noise cancellation techniques. We have applied two software gradiometry methods to analyze the time series of signal and reference data recorded outside magnetic shielding with high temperature superconducting quantum interference device (HTS SQUID) based gradiometers. One method uses adaptive frequency dependent gradiometer coefficients determined in the Fourier domain to subtract the reference

M. Bick; K. Sternickel; G. Panaitov; A. Effern; Y. Zhang; H.-J. Krause

2001-01-01

367

Leaching characteristics of fly ash  

Microsoft Academic Search

The disposal of fly ash as a byproduct of thermic power stations, results in significant environmental problems. The leaching of coal fly ash during disposal is of concern for possible contamination, especially for the aquatic environment when ash is in contact with water. The aim of this study was to investigate the leaching behaviour of fly ashes currently disposed in

Aysenur Ugurlu

2004-01-01

368

Fat Fruit Flies  

E-print Network

Broadcast Transcript: Breaking news from South Korea's hi-tech frontline. With the help of drosophila, or the fruit fly, scientists here have discovered strands of genetic material that control growth in the body. They're called micro-RNA and people...

Hacker, Randi

2010-08-11

369

Wisdom from the fly.  

PubMed

Arguably, almost all research in Drosophila can be considered basic research, yet many of the most essential and fundamental concepts of human genetics were first decoded in the fly. Although the fly genome, which is organized into only four chromosomes, is approximately one-twentieth the size of the human genome, it contains roughly the same number of genes, and up to 75% of human disease-related genes have Drosophila homologues [1]. The fly was prized for its simplicity and utility even before such compelling homology with humans was apparent. Since Thomas Hunt Morgan began his seminal experiments over a century ago (Table 1), the Drosophila system has revealed countless key mechanisms by which cells function, including the factors that maintain chromatin and the signaling pathways that control cell fate determination and organism development. More recently, the fly has emerged as a critical neurobiological tool and disease model for a range of genetic disorders. In this review, we present a brief retrospective of Drosophila as an indispensable genetic system and discuss some of the many contributions, past and present, of this facile system to human genetics. PMID:25161083

Rieder, Leila E; Larschan, Erica N

2014-11-01

370

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

371

Cockroaches, House flies  

NSDL National Science Digital Library

Chapters 5-10 of a World Health Organization PDF on medical pests of importance in PDF format. Chatpers 5,6 cover Cockroaches and House flies respectively, remaining chapters go on to discuss guinea worm, fresh water snails, and proper pesticide application. These are extremely thorough control strategy texts with a great deal of information.

0002-11-30

372

Fly a Leaf  

NSDL National Science Digital Library

In this outdoor, windy day activity, learners "fly" and race leaves along a line to discover which types of leaves catch the most wind. Which leaves are the best fliers? Why? Learners think about wind as an important environmental and physical factor, and how plants must adapt to its influence. What a fun way to take advantage of a windy day!

Science, Lawrence H.

1982-01-01

373

The Laminar Flame Speedup by Neon-22 Enrichment in White Dwarf Supernovae  

E-print Network

Carbon-oxygen white dwarfs contain neon-22 formed from alpha-captures onto nitrogen during core He burning in the progenitor star. In a white dwarf (type Ia) supernova, the neon-22 abundance determines, in part, the neutron-to-proton ratio and hence the abundance of radioactive nickel-56 that powers the lightcurve. The neon-22 abundance also changes the burning rate and hence the laminar flame speed. We tabulate the flame speedup for different initial carbon and neon-22 abundances and for a range of densities. This increase in the laminar flame speed--about 30% for a neon-22 mass fraction of 6%--affects the deflagration just after ignition near the center of the white dwarf, where the laminar speed of the flame dominates over the buoyant rise, and in regions of lower density ~ 10^7 g/cm3 where a transition to distributed burning is conjectured to occur. The increase in flame speed will decrease the density of any transition to distributed burning.

David A. Chamulak; Edward F. Brown; Francis X. Timmes

2006-12-18

374

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.

2011-10-01

375

The Microstrip SQUID Amplifier: Searching for the Axion  

NASA Astrophysics Data System (ADS)

The axion detector [1] at LLNL requires a very low noise amplifier in the 1-GHz frequency range. In the first generation detector, the cavity was cooled to 1.5 K and the amplifier was a HEMT (High Electron Mobility Transistor) with a noise temperature TN of 1.7 K. Thus, the system noise temperature Ts was 3.2 K. In an attempt to achieve significantly lower noise temperatures, we fabricated amplifiers based on the dc SQUID [2] (Superconducting QUantum Interference Device). The theory [3] for SQUID amplifiers with a resonant input circuit predicts that an optimized device at sufficiently low temperatures should be quantum limited, that is, TN = hf/k at frequency f. To extend the operating frequency to the gigahertz range, we developed the Microstrip SQUID Amplifier (MSA) in which the input coil forms a microstrip with the SQUID washer [4, 5]. When the length of the coil corresponds to a half-wavelength of the signal, the gain is typically 20 dB. We measured the gain and noise [6] of an MSA in which the resistive shunts of the junctions were coupled to cooling fins to reduce hot electron effects [7]. At 0.62 GHz, we achieved a minimum noise temperature TN = 48±5mK for a bath temperature of 50 mK and at a frequency below resonance, as predicted. The quantum limit is 30 mK. Since the time for the axion detector to scan a given frequency range scales as Ts2, replacing the HEMT with a SQUID and cooling the cavity to 50 mK potentially reduces the scan time by three orders of magnitude.

Clarke, John

2009-12-01

376

Volume 40, number 4 OPTICS COMMUNICATIONS 15 January 1982 COLOR CENTER LASER OPTOGALVANIC SPECTROSCOPY OF LITHIUM, BARIUM, NEON  

E-print Network

SPECTROSCOPY OF LITHIUM, BARIUM, NEON AND ARGON RYDBERG STATES IN HOLLOW CATHODE DISCHARGES Marianne H operating in the range 3600-4100 cm-`. Transitions in lithium and barium atoms sputtered from the cathodes of Rydberg transitions in lithium, barium, neon and ar- gon using a color center laser operating

Cohen, Ronald C.

377

mm wave and THz imaging using very inexpensive neon-indicator lamp detector focal-plane arrays  

Microsoft Academic Search

Development of focal plane arrays (FPA) for mm wavelength and THz radiation is presented in this paper. The FPA is based upon inexpensive neon indicator lamp Glow Discharge Detectors (GDDs) that serve as pixels in the FPA. It was shown in previous investigations that inexpensive neon indicator lamps GDDs are quite sensitive to mm wavelength and THz radiation. The diameter

D. Rozban; A. Levanon; A. Akram; A. Abramovich; N. S. Kopeika; H. Joseph; Y. Yitzthaky; A. Belenky; O. Yadid-Pecht

2011-01-01

378

Liquid neon heat transfer as applied to a 30 tesla cryomagnet  

NASA Technical Reports Server (NTRS)

A 30-tesla magnet design is studied which calls for forced convection liquid neon heat transfer in small coolant channels. The design also requires suppressing boiling by subjecting the fluid to high pressures through use of magnet coils enclosed in a pressure vessel which is maintained at the critical pressure of liquid neon. This high pressure reduces the possibility of the system flow instabilities which may occur at low pressures. The forced convection heat transfer data presented were obtained by using a blowdown technique to force the fluid to flow vertically through a resistance heated, instrumented tube.

Papell, S. S.; Hendricks, R. C.

1975-01-01

379

Test What You Fly?  

NASA Technical Reports Server (NTRS)

It was the first time on any NASA project I know of that all the instruments on an observatory came off for rework or calibration after the full range of environmental tests, and then were reintegrated at the launch center without the benefit of an observatory environmental retest. Perhaps you've heard the expression, 'Test what you fly, fly what you test'? In theory, it's hard to argue with that. In this case, I was willing to take the risk of not testing what I flew. As the project manager for the Advanced Composition Explorer (ACE) mission, I was the one who ultimately decided what risks to take, just as it was my responsibility to get buy-in from the stakeholders.

Margolies, Don

2002-01-01

380

Two-stage SQUID systems and transducers development for MiniGRAIL  

NASA Astrophysics Data System (ADS)

We present measurements on a two-stage SQUID system based on a dc-SQUID as a sensor and a DROS as an amplifier. We measured the intrinsic noise of the dc-SQUID at 4.2 K. A new dc-SQUID has been fabricated. It was specially designed to be used with MiniGRAIL transducers. Cooling fins have been added in order to improve the cooling of the SQUID and the design is optimized to achieve the quantum limit of the sensor SQUID at temperatures above 100 mK. In this paper we also report the effect of the deposition of a Nb film on the quality factor of a small mass Al5056 resonator. Finally, the results of Q-factor measurements on a capacitive transducer for the current MiniGRAIL run are presented.

Gottardi, L.; Podt, M.; Bassan, M.; Flokstra, J.; Karbalai-Sadegh, A.; Minenkov, Y.; Reinke, W.; Shumack, A.; Srinivas, S.; de Waard, A.; Frossati, G.

2004-03-01

381

Wide-band tuneability, nonlinear transmission, and dynamic multistability in SQUID metamaterials  

NASA Astrophysics Data System (ADS)

Superconducting metamaterials comprising rf SQUIDs (Superconducting QUantum Interference Devices) have been recently realized and investigated with respect to their tuneability, permeability and dynamic multistability properties. These properties are a consequence of intrinsic nonlinearities due to the sensitivity of the superconducting state to external stimuli. SQUIDs, made of a superconducting ring interrupted by a Josephson junction, possess yet another source of nonlinearity, which makes them widely tuneable with an applied dc dlux. A model SQUID metamaterial, based on electric equivalent circuits, is used in the weak coupling approximation to demonstrate the dc flux tuneability, dynamic multistability, and nonlinear transmission in SQUID metamaterials comprising non-hysteretic SQUIDs. The model equations reproduce the experimentally observed tuneability patterns, and predict tuneability with the power of an applied ac magnetic magnetic field. Moreover, the results indicate the opening of nonlinear frequency bands for energy transmission through SQUID metamaterials, for sufficiently strong ac fields.

Tsironis, G. P.; Lazarides, N.; Margaris, I.

2014-09-01

382

Some phenomena due to SQUID input properties when local feedback is present  

NASA Astrophysics Data System (ADS)

We have constructed a two-stage SQUID amplifier, in which series-mixing local feedback has been used to screen the SQUID input inductances and hence to boost the power gain of the amplifier. 2.9 pA/Hz1/2 current noise and 2.9 nH input inductance of the lower SQUID stage imply energy resolution of 18 times Planck constant at 4.2 K, which, arguably, can be further improved by input inductance screening. The upper stage consists of a 184-series 4-parallel SQUID array, which, when used alone, shows lower than 0.03 ??0/Hz2 flux noise, but which as a part of the two-stage amplifier is operated at a higher flux noise level to provide robust, EMI-tolerant output signal. The series-mixing feedback also facilitates negative SQUID input impedance, which would allow self-oscillating SQUID-based frequency domain multiplexing.

Kiviranta, Mikko; Grönberg, Leif; Beev, Nikolai; van der Kuur, Jan

2014-05-01

383

Origami Flying Disk  

NSDL National Science Digital Library

In this three-part activity, learners use paper to explore Bernoulli's Principle — fast-moving air has lower pressure than non-moving air. First, learners observe what happens when they hold a paper strip between their lips and blow. Then, learners conduct another test to examine how airplane wings provide lift. Finally, learners make an origami flying disc using only paper, tape, and their newfound knowledge of Bernoulli's Principle.

Cy Tymony

2011-01-01

384

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

385

Inspection of thermal aging of primary piping systems in nuclear power plants with SQUID magnetometer  

SciTech Connect

Superconducting quantum interference device (SQUID) was used for the detection of thermal aging of duplex stainless steels. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the material property changes due to thermal aging at the operating temperature of light water reactors. Besides, the change in the SQUID output was more significant as the unaged specimens had more ferrite content.

Isobe, Y.; Aoki, K.; Nakayasu, F. [Nuclear Fuel Industries Ltd., Osaka (Japan)

1996-09-01

386

Reducing systematic errors in measurements made by a SQUID magnetometer  

NASA Astrophysics Data System (ADS)

A simple method is described which reduces those systematic errors of a superconducting quantum interference device (SQUID) magnetometer that arise from possible radial displacements of the sample in the second-order gradiometer superconducting pickup coil. By rotating the sample rod (and hence the sample) around its axis into a position where the best fit is obtained to the output voltage of the SQUID as the sample is moved through the pickup coil, the accuracy of measuring magnetic moments can be increased significantly. In the cases of an examined Co1.9Fe1.1Si Heusler alloy, pure iron and nickel samples, the accuracy could be increased over the value given in the specification of the device. The suggested method is only meaningful if the measurement uncertainty is dominated by systematic errors - radial displacement in particular - and not by instrumental or environmental noise.

Kiss, L. F.; Kaptás, D.; Balogh, J.

2014-11-01

387

High-resolution magnetic mapping using a SQUID magnetometer array  

SciTech Connect

This paper reports on a four-channel, high-resolution, Superconducting Quantum Interference Device (SQUID) magnetometer array used to map magnetic fields from various samples. Each SQUID has a 3 mm diameter pickup coil located 4.4 mm from the adjacent channel. The spacing between the cryogenic array and the room temperature sample is adjustable from 1.5 mm to 4.0 mm. We mapped the field from a 350 {mu}m diameter hole in an 11 cm {times} 15 cm {times} 60 {mu}m copper sheet that was carrying a current of 100 mA. Field shape and strength were compared with predictions from analytical and finite element models, which indicate that this technique should be able to detect an order of magnitude smaller flaws in flat plates.

Staton, D.J.; Ma, Y.P.; Sepulveda, N.G.; Wikswo, J.P. Jr. (Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics and Astronomy)

1991-03-01

388

Nested Sphere Model for SQUID-based Impedance Magnetocardiography  

NASA Astrophysics Data System (ADS)

An axisymmetric FEM model is used to predict the SQUID response to changes in tissue conductivity and blood volume during the cardiac cycle. The heart is modeled as a nested sphere inside a cylindrical conducting thorax. The current density and resulting magnetic field is calculated during end systolic, end diastolic and diastolic phases. Modeling results are compared to Impedance Magnetocardiography (IMCG) measurements made using a High-Tc SQUID magnetometer in an unshielded environment .In this measurements, a low amplitude ac current is passed through the body through outer electrodes. Variations in blood flow during the cardiac cycle perturb currents that give rise to time varying magnetic fields amplitudes. Applications to inductive IMCG will be discussed.

Vajrala, Vijayanand; Nawarathna, Dharmakeerthi; Claycomb, James; Miller, John

2004-03-01

389

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

390

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

NASA Astrophysics Data System (ADS)

Cephalopods are an important prey resource for fishes, seabirds, and marine mammals, and are also voracious predators on crustaceans, fishes, squid and zooplankton. Because of their high feeding rates and abundance, squids have the potential to exert control on the recruitment of commercially important fishes. In this review, we synthesize the available information for two intrinsic markers (?15N and ?13C isotopic values) in squids for all oceans and several types of ecosystems to obtain a global view of the trophic niches of squids in marine ecosystems. In particular, we aimed to examine whether the trophic positions and trophic widths of squid species vary among oceans and ecosystem types. To correctly compare across systems, we adjusted squid ?15N values for the isotopic variability of phytoplankton at the base of the food web provided by an ocean circulation-biogeochemistry-isotope model. Studies that focused on the trophic ecology of squids using isotopic techniques were few, and most of the information on squids was from studies on their predators. Our results showed that squids occupy a large range of trophic positions and exploit a large range of trophic resources, reflecting the versatility of their feeding behavior and confirming conclusions from food-web models. Clear differences in both trophic position and trophic width were found among oceans and ecosystem types. The study also reinforces the importance of considering the natural variation in isotopic values when comparing the isotopic values of consumers inhabiting different ecosystems.

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

2013-10-01

391

76 FR 13887 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish (MSB...  

Federal Register 2010, 2011, 2012, 2013, 2014

...States; Atlantic Mackerel, Squid, and Butterfish (MSB) Fishery; Revision of 2011 Butterfish Specifications AGENCY: National Marine...This emergency action increases the butterfish allowable biological catch (ABC)...

2011-03-15

392

Time-division SQUID multiplexers with reduced sensitivity to external magnetic fields  

E-print Network

Time-division SQUID multiplexers are used in many applications that require exquisite control of systematic error. One potential source of systematic error is the pickup of external magnetic fields in the multiplexer. We present measurements of the field sensitivity figure of merit, effective area, for both the first stage and second stage SQUID amplifiers in three NIST SQUID multiplexer designs. These designs include a new variety with improved gradiometry that significantly reduces the effective area of both the first and second stage SQUID amplifiers.

Stiehl, G M; Hilton, G C; Irwin, K D; Mates, J A B; Reintsema, C D; Zink, B L

2010-01-01

393

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

394

Jumbo squid beaks: Inspiration for design of robust organic composites  

Microsoft Academic Search

The hard tissues found in some invertebrate marine organisms represent intriguing paradigms for robust, lightweight materials. The present study focuses on one such tissue: that comprising the beak of the jumbo squid (Dosidicus gigas). Its main constituents are chitin fibers (15–20wt.%) and histidine- and glycine-rich proteins (40–45%). Notably absent are mineral phases, metals and halogens. Despite being fully organic, beak

Ali Miserez; Youli Li; J. Herbert Waite; Frank Zok

2007-01-01

395

High-Tc SQUID Magnetometers for Industrial Applications  

Microsoft Academic Search

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 Omega) 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

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

1998-01-01

396

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

397

The Temperature Dependence of High-TC SQUID Magnetometers  

Microsoft Academic Search

We have investigated the response of the flux-locked output of several high-TC SQUID magnetometers to small changes in temperature and for magnetic fields 0-30 mu T. The temperature response DT ? d phiS \\/dT is observed to be linear in the applied magnetic field Ba and can be as large as 500 m phio \\/K where phiS is the flux

R. H. Koch; F. P. Milliken; S. L. Brown; R. A. Altman; W. J. Gallagher; S. G. Haupt; D. K. Lathrop

1997-01-01

398

Superconducting state in a circular SQUID shaped mesoscopic film  

NASA Astrophysics Data System (ADS)

Using a thin-film approach to the time-dependent Ginzburg-Landau theory, we have studied the magnetization and order parameter profile in a thin mesoscopic superconductor in the so-called SQUID geometry. Our sample is circular with a hole at the center connected to the outer rim by a very thin slit. We have also studied the influence of the boundary conditions in the thin slit on the magnetization curve of the sample.

Barba-Ortega, J.; Aguilar, Jose L.; González, Jesús D.

2014-11-01

399

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

400

Some Factors Influencing Sodium Extrusion by Internally Dialyzed Squid Axons  

Microsoft Academic Search

Squid giant axons were internally dialyzed by a technique pre- viously described. In an axon exposed to cyanide seawater for 1 hr and dialyzed with an ATP-free medium, the Na efflux had a mean value of 1.3 pmole\\/cm~sec when (Na)~ was 88 re_M, in quantitative agreement with flux ratio calculations for a purely passive Na movement. When ATP at a

L. J. Mullins; F. J. BRINLEY

1967-01-01

401

Absolute calibration and beam background of the Squid Polarimeter  

SciTech Connect

The problem of beam background in Squid Polarimetry is not without residual benefits. The authors may deliberately generate beam background by gently kicking the beam at the spin tune frequency. This signal may be used to accomplish a simple and accurate absolute calibration of the polarimeter. The authors present details of beam background calculations and their application to polarimeter calibration, and suggest a simple proof-of-principle accelerator experiment.

Blaskiewicz, M.M.; Cameron, P.R.; Shea, T.J. [and others

1996-12-31

402

Integrated SQUID-gradiometer system for magnetocardiography without magnetic shielding  

Microsoft Academic Search

First-order planar superconducting quantum interface device (SQUID) gradiometers were fabricated on the basis of the Nb\\/AlOX\\/Nb technology developed at IPHT Jena. The gradiometers have two pickup loops each with quadratic dimensions of 2 cm and a baseline of 4 cm, integrated on chip. The intrinsic noise corresponds to a field resolution in one loop better than 3 fT\\/?Hz. Because of

Ronny Stolz; V. Zakosarenko; N. Bondarenko; M. Schulz; L. Fritzsch; N. Oukhanski; H.-G. Meyer

2003-01-01

403

The Winnowing: Establishing the Squid-Vibrio Symbiosis  

NSDL National Science Digital Library

This Nature Reviews Microbiology article examines the symbiosis between the squid Euprymna scolopes and its luminous bacterial symbiont, Vibrio fischeri. Using image-rich illustrations, it depicts the progression of light-organ colonization as a series of steps and discusses the advent of genomic approaches used to study this model system. A subscription is required to access the full-text version of this article.

Nyholm, Spencer V.; Mcfall-Ngai, Margaret; Microbiology, Nature R.

404

Pest Control on the "Fly"  

NASA Technical Reports Server (NTRS)

FlyCracker(R), a non-toxic and environmentally safe pesticide, can be used to treat and control fly problems in closed environments such as milking sheds, cattle barns and hutches, equine stables, swine pens, poultry plants, food-packing plants, and even restaurants, as well as in some outdoor animal husbandry environments. The product can be applied safely in the presence of animals and humans, and was recently permitted for use on organic farms as livestock production aids. FlyCracker's carbohydrate technology kills fly larvae within 24 hours. By killing larvae before they reach the adult stages, FlyCracker eradicates another potential breeding population. Because the process is physical-not chemical-flies and other insects never develop resistance to the treatment, giving way to unlimited use of product, while still keeping the same powerful effect.

2002-01-01

405

Fabrication and characterization of shunted μ-SQUID  

NASA Astrophysics Data System (ADS)

In order to eliminate hysteresis, we have fabricated and characterized niobium based shunted micron size superconducting quantum interference devices (?-SQUIDs). We find a wide temperature range where these ?-SQUIDs are non-hysteretic in nature and show a very good Ic vs. B oscillations in hysteretic regime and V vs. B oscillations in non-hysteretic regime. Here we report the characteristics of a shunted- ?-SQUID (Wf38LS72D5). In this device we have achieved a large voltage modulation, in non-hysteretic regime, at various temperatures including such as 1.1 mV at 6.62 K with a transfer function V? = 7.2mV/?0. The figures within the original article PDF file, as supplied to AIP Publishing, were affected by a PDF-processing error. Consequently, the article re-flowed and pagination increased from 3 to 4 pages. This article was updated on 14 May 2014 to correct the PDF-processing error, with the scientific content remaining unchanged. Readers are advised that the replacement article PDF file contains an additional blank page to preserve the original pagination.

Kumar, Nikhil; Fournier, T.; Courtois, H.; Gupta, Anjan K.

2014-04-01

406

Design and applications of a scanning SQUID microscope  

SciTech Connect

The scanning SQUID (Superconducting Quantum Interference Device) microscope is an extremely sensitive instrument for imaging local magnetic fields. The authors describe one such instrument which combines a novel pivoting lever mechanism for coarse-scale imaging with a piezoelectric tube scanner for fine-scale scans. The magnetic field sensor is an integrated miniature SQUID magnetometer. This instrument has a demonstrated magnetic field sensitivity of <10{sup {minus}6} gauss/{radical}Hz at a spatial resolution of {approximately}10 {micro}m. The design and operation of this scanning SQUID microscope are described, and several illustrations of the capabilities of this technique are presented. The absolute calibration of this instrument with an ideal point source, a single vortex trapped in a superconducting film, is shown. The use of this instrument for the first observation of half-integer flux quanta, in tricrystal thin-film rings of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}, is described. The half-integer flux quantum effect is a general test of the symmetry of the superconducting order parameter. One such test rules out symmetry-independent mechanisms for the half-integer flux quantum effect, and proves that the order parameter in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} has lobes and nodes consistent with d-wave symmetry.

Kirtley, J.R.; Ketchen, M.B.; Tsuei, C.C.; Sun, J.Z.; Gallagher, W.J.; Yu-Jahnes, L.S.; Gupta, A.; Stawiasz, K.G.; Wind, S.J.

1995-11-01

407

Build a Fruit Fly Trap  

NSDL National Science Digital Library

In this construction activity, students use a 2-liter bottle to build a fly trap. There is not much supporting information besides the directions, but the trap can be used to examine fly behavior, and it might also be redesigned by students. In the construction part of the activity, younger learners will need help and supervision from an older learner or adult, but any age learner can do independent observation of fly behavior once insects are inside the trap.

Wisconsin-Madison, Universitiy O.

2007-01-01

408

Porous materials from fly ash  

SciTech Connect

Large quantity of fly ash is generated every year from the electric power plants. Due to the shortage of disposal sites and tighter regulations, new viable ways of utilizing fly ash are needed. The formation of a porous material comprising fly ash was investigated. It was found that a porous material can be made by mixing fly ash with phosphoric acid, followed by heat treatment. The porous material is light-weight (bulk density {approximately} 1 g/cm{sup 3}), machinable, and with reasonable strength. Due to the high percentage of close porosity, the porous material has a great potential for thermal insulation applications.

Moeller, J.G.; Shih, W.H. [Drexel Univ., Philadelphia, PA (United States). Dept. of Materials Engineering

1996-12-31

409

FORMATION AND INTERACTION OF HOLLOW NEON ATOMS AT AN ALUMINUM SURFACE  

Microsoft Academic Search

Theoretical and experimental methods were used to study the interaction of Ne 9+ ions with an Al surface. Theoretical models were applied to visualize the shape and dimension of hollow neon atoms formed above and below the surface. Atomic Hartree-Fock calculations were performed to determine the large hollow atoms produced with electrons in high Rydberg levels above the surface. Inside

N. Stolterfoht; D. Niemann; M. Grether; A. Spieler; A. Arnau

1998-01-01

410

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

411

Helium isotope effect and solubility of helium and neon in distilled water and seawater  

NASA Astrophysics Data System (ADS)

Solubilities of helium and neon were determined in distilled water and seawater equilibrated with the atmosphere in the 0-20°C temperature range. Small differences were found between the present results and those of Weiss. The isotopic fractionation of helium in solution was found to resemble closely the trend determined by Benson and Krause.

Top, Z.; Eismont, W. C.; Clarke, W. B.

1987-07-01

412

Helium-neon laser radiation effect on some teratogenic processes in fish embryos  

NASA Astrophysics Data System (ADS)

Helium-neon laser irradiation increased production of normal fish hatchlings as a result of eggs irradiation at gastrulation and embryonal motorics stages and negatively influenced at organogenesis stage. Role of main contributing factors-embryos survival and morphological anomalies in this process is investigated.

Uzdensky, Anatoly B.; Gorbacheva, Ludmila T.; Vorob'eva, Olga A.; Son, Chor-gun

2001-07-01

413

Building complex heterogeneous measurement and data systems: Combining ecology and systems engineering at NEON  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is an NSF-funded facility to enable the understanding of how ecological processes occurring on multiple spatial and temporal scales are inter-related, through the deployment of measurement and observation infrastructure across the continental US, Alaska, Hawaii, and Puerto Rico. Two overriding features of NEON's design are an emphasis on the integration of system engineering principles with this infrastructure deployment, and the deep involvement, since its inception, of the ecological community in helping to define, shape, and realize NEON's potential. This synergy is being leveraged to build a novel, unique facility that will be both nimble and long-lived. We discuss first how traditional systems engineering principles, typically applied only to instrumental systems, are being applied to the wide array of NEON measurement and observation infrastructure, both to achieve construction completion but also to serve as a consistent and informative guide to building infrastructure for ecological and environmental research. We also describe how the scientific and engineering community has contributed to these activities, and derive some important guiding principles within their synergy.

Berukoff, S. J.

2013-12-01

414

Strong interaction effects in the 2p-1s transition in pionic neon  

NASA Astrophysics Data System (ADS)

We present experimental results for the 2p-1s transition energy and the natural line-width of the 1s state in pionic neon. The line width if?=14.5 ± 3.0 keV is in substantial agreement with semiphenomenological low-energy pion-nucleus interaction theories in the region A ? 20.

Eckhause, M.; Kane, F. R.; Kane, J. R.; Martin, P.; Miller, G. H.; Spence, C. B.; Welsh, R. E.

1972-07-01

415

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

416

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

417

NEON Collaborative Data Collection Campaign at Pacific South West Site in California  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is a continental-scale observatory that will collect biological, chemical and geophysical data over the continental United States in order to study biodiversity, landcover change, climate change and invasive species. In June 2013, a large-scale data collection took place over NEON's Pacific South West (PSW) site 17 in CA, USA. Data were collected in the San Joaquin Experimental Range and the Sierra National Forest. NEON's AOP (Airborne Observation Platform) acquired high spatial resolution hyperspectral data (~1m pixels), waveform lidar, discrete lidar, and RGB imagery over all three sites. A field team simultaneously collected atmospheric and vegetation inventory data, including tree locations, height, diameter-at-breast-height (DBH), species, and spectral data. The NEON collect was centered within a collaboration of multiple research entities, including NASA, Rochester Institute of Technology (RIT), University of Massachusetts (Boston; UMB, and Lowell; UML), Boston University (BU), and the University of Wisconsin, Madison (UWM). NASA's AVIRIS and MASTER sensors were flown over a wider area encompassing the NEON sites, with AVIRIS acquiring hyperspectral data (224 bands) at approximately 30m spatial resolution, and MASTER acquiring multispectral thermal data (50 bands) at approximately 50m spatial resolution. These data will be downscaled to approximate theoretical HyspIRI data (60m spatial resolution) as part of a large collection of preparatory research. Concurrently, a variety of university teams were active in the field: RIT collected ground-based lidar, leaf area index (LAI), herbaceous biomass measurements, wide-angle photographs, and spectral measurements. Data were collected over 20 80x80m sites, centered on existing 20x20m NEON sites. This data set will be used to inform synthetic scene design and to study the impact of sub-pixel structural variation on pixel-level spectral response; The BU, UMB, and UML team surveyed three sites in the Sierras with their terrestrial waveform lidar (DWEL) and collected Trac measurements of LAI, while UMB collected additional discrete ground-based lidar scans and additional forestry measures at San Joaquin and the Sierras; A team from the UWM collected leaf-level reflectance and transmission spectra and measured leaf-level gas exchange and chlorophyll fluorescence. This multifaceted collaboration, funded by the NSF NEON and NASA HyspIRI Preparatory Science programs, will support key scientific developments by combining the expertise from multiple sensing modalities. This experiment highlights the advantages of data and skills sharing in remote sensing applications. An overview of the larger effort and individual early science will be presented.

Kampe, T. U.; Leisso, N.; Krause, K.; Musinsky, J.; Petroy, S. B.; Wasser, L. A.; Cawse-Nicholson, K.; van Aardt, J. A.; Schaaf, C.; Strahler, A. H.; Serbin, S. P.

2013-12-01

418

A transparent and transferable framework to interpret data quality of NEON's terrestrial sensor measurements  

NASA Astrophysics Data System (ADS)

A fundamental role of the National Ecological Observatory Network (NEON) is to offer high quality and transparent data to the community. Yet, data is seemingly useless without the ability to assess its validity. Therefore, it is essential for NEON to implement a method that allows users to assess the quality of its data. Since tower-based sensors represent a large portion of NEON's automated measurements, it is critical that any ambiguity in sensor measurements are captured and quantified. Initial data quality of tower sensor measurements will be based on a suite of quality assurance and quality control (QA/QC) analyses as well as sensor flags. This will result in 'data products' (data produced by NEON) being accompanied with a set of 'quality flags' (QA/QC and sensor flags). However, the magnitude of data that will be generated by NEON requires developing a framework for summarizing data quality information. In order to accommodate varying use cases and levels of expertise, such a framework should provide several levels of detail. NEON is not alone in this challenge, as there is a continued need for large data sets to answer the research questions of tomorrow. Thus, a framework was created with the intention of meeting the needs of NEON, while maintaining interoperability across disciplines. The framework consists of presenting quality information for each data product through two separate schemes; a quality report and a quality summary. The quality report presents the results of specific quality flags as they relate to individual observations. For example, the quality report for a thirty-minute temperature average, sampled at a rate of 1 Hz, allows the user to differentiate the 1800 outcomes for the QA/QC analyses and sensor flags. The quality summary instead provides a 'quality metric' for each quality flag. A quality metric summarizes, as a percentage, the results of the QA/QC analyses and sensor flags for the observations that were used to calculate a data product. Included in the quality summary is a final quality flag, which allows users to quickly assess whether a data product has been deemed valid or invalid. The final quality flag assesses whether the observations used to create a data product exceeded a predetermined threshold value of failed QA/QC analyses and sensor flags. This objective approach assesses the quality of a data product and retains several levels of detail in order to facilitate data transparency and usability. Furthermore, this framework can aid in problem tracking and resolution, should sensor or system malfunctions arise.

Smith, D.; Metzger, S.; Taylor, J. R.

2013-12-01

419

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

Federal Register 2010, 2011, 2012, 2013, 2014

NMFS is prohibiting directed fishing for sculpins, sharks, squid, and octopus in the Gulf of Alaska (GOA). This action is necessary to prevent exceeding the 2011 total allowable catch (TAC) of sculpins, sharks, squid, and octopus in the...

2011-01-19

420

Vision in flying insects.  

PubMed

Vision guides flight behaviour in numerous insects. Despite their small brain, insects easily outperform current man-made autonomous vehicles in many respects. Examples are the virtuosic chasing manoeuvres male flies perform as part of their mating behaviour and the ability of bees to assess, on the basis of visual motion cues, the distance travelled in a novel environment. Analyses at both the behavioural and neuronal levels are beginning to unveil reasons for such extraordinary capabilities of insects. One recipe for their success is the adaptation of visual information processing to the specific requirements of the behavioural tasks and to the specific spatiotemporal properties of the natural input. PMID:12490262

Egelhaaf, Martin; Kern, Roland

2002-12-01

421

Robber Flies (Asilidae)  

NSDL National Science Digital Library

This Web site focuses on "one of the largest and most abundant families of present day insects" -- the Robber Flies. Maintained by Fritz Geller-Grimm of the Museum Wiesbaden in Germany and Cornell University graduate student Torsten Dikow, the site includes a variety of information on many aspects of these insects. The Asilidae section contains many resources that are most appropriate for an advanced or research audience, including identification keys, species and distribution databases, and literature references. The Dipterology and Entomology sections include plenty of more general information suitable for a variety of audiences.

2008-09-15

422

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.

423

Flying tryps: survival and maturation of trypanosomes in tsetse flies.  

PubMed

Survival in and colonization of the tsetse fly midgut are essential steps in the transmission of many species of African trypanosomes. In the fly, bloodstream trypanosomes transform into the procyclic stage within the gut lumen and later migrate to the ectoperitrophic space, where they multiply, establishing an infection. Progression of the parasite infection in the fly depends on factors inherent to the biology of trypanosomes, tsetse, and the bloodmeal. Flies usually eradicate infection early on with both pre-existing and inducible factors. Parasites, in contrast, respond to these stimuli by undergoing developmental changes, allowing a few to both survive and migrate within the tsetse. Here we discuss parasite and fly factors determining trypanosome colonization of the tsetse, focusing mainly on the midgut. PMID:23507033

Dyer, Naomi A; Rose, Clair; Ejeh, Nicholas O; Acosta-Serrano, Alvaro

2013-04-01

424

Effect of addition of hydrogen to neon buffer gas of copper bromide vapor laser on its spectral and temporal characteristics  

NASA Astrophysics Data System (ADS)

The effect of addition of hydrogen to the neon buffer gas of copper bromide vapor laser on its output of green (510.6 nm) and yellow (578.2 nm) spectral components is reported. The increase of average power of the laser output and its distribution in the two spectral components is studied as a function of percentage of hydrogen in neon at different input electrical powers. The change in pulse-duration and temporal separation between onsets of the green and yellow components with change of percentage of hydrogen in neon at different input electrical powers is also reported.

Tiwari, G. N.; Shukla, P. K.; Mishra, R. K.; Shrivastava, V. K.; Khare, R.; Nakhe, S. V.

2015-03-01

425

Flies, clocks and evolution.  

PubMed Central

The negative feedback model for gene regulation of the circadian mechanism is described for the fruitfly, Drosophila melanogaster. The conservation of function of clock molecules is illustrated by comparison with the mammalian circadian system, and the apparent swapping of roles between various canonical clock gene components is highlighted. The role of clock gene duplications and divergence of function is introduced via the timeless gene. The impressive similarities in clock gene regulation between flies and mammals could suggest that variation between more closely related species within insects might be minimal. However, this is not borne out because the expression of clock molecules in the brain of the giant silk moth, Antheraea pernyi, is not easy to reconcile with the negative feedback roles of the period and timeless genes. Variation in clock gene sequences between and within fly species is examined and the role of co-evolution between and within clock molecules is described, particularly with reference to adaptive functions of the circadian phenotype. PMID:11710984

Rosato, E; Kyriacou, C P

2001-01-01

426

Passive Baited Sequential Fly Trap  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sampling fly populations associated with human populations is needed to understand diel behavior and to monitor population densities before and after control operations. Population control measures are dependent on the results of monitoring efforts as they may provide insight into the fly behavior ...

427

Wasps as Fly-Killers  

Microsoft Academic Search

YOUR correspondent at p. 385, vol. xxx., may be informed that in this part of the world wasps enter dwellings by the open windows in summer-time, and hunt house-flies unmercifully, leaving the dead flies in hundreds on the floors, ready to be swept into a dustpan. This occurs only in the country, and where wasps' nests are near by. Westwood

George Lawson

1884-01-01

428

Improving the sensitivity of a high-Tc SQUID at MHz frequency using a normal metal transformer  

Microsoft Academic Search

Superconducting quantum interference devices (SQUIDs) can be used to detect the signals of nuclear quadrupole resonance (NQR). The NQR frequencies of some interesting materials are in the order of MHz. However, the sensitivity of a high-Tc SQUID is normally not enough to detect the weak NQR signals. To improve the sensitivity of a high-Tc SQUID at MHz frequency, we used

D. F. He; H. Itozaki; M. Tachiki

2006-01-01

429

A simple three-channel dc SQUID system using time domain multiplexing M. Mck and M. Korn  

E-print Network

. By connecting all the SQUIDs and all the feedback coils in series, this time domain multiplexed system requires and its feedback coil. Some time ago, we proposed a three-channel rf SQUID system with time domainA simple three-channel dc SQUID system using time domain multiplexing M. Mück and M. Korn Justus

Le Roy, Robert J.

430

Nonlinear Phenomena in Complex Systems, vol. 11, no. 2 (2008), pp. 250 -258 Dissipative Discrete Breathers in rf SQUID Metamaterials  

E-print Network

Breathers in rf SQUID Metamaterials N. Lazarides, G. P. Tsironis, and M. Eleftheriou Department of Physics of dissipative discrete breathers (DDBs) in rf superconducting quantum interference device (SQUID) arrays in both one and two dimensions is investigated numerically. In an rf SQUID array, the nonlinearity which

Tsironis, Giorgos P.

431

Enhancement of SQUID-Detected NMR Signals with Hyperpolarized Liquid 129 in a 1 T Magnetic Field  

E-print Network

Enhancement of SQUID-Detected NMR Signals with Hyperpolarized Liquid 129 Xe in a 1 T Magnetic Field using a commercial high-Tc SQUID magnetometer with a signal-to-noise ratio of up to 1000 from a single-to-noise ratio (SNR) still decreases linearly with the magnetic field. Here we report on the first use of SQUIDs

Romalis, Mike

432

SQUID DETECTION OF EPR IN DILUTE CMN* R.V.Chamberlin, L.A. Moberly and O.G. Symko  

E-print Network

SQUID DETECTION OF EPR IN DILUTE CMN* R.V.Chamberlin, L.A. Moberly and O.G. Symko Dept. of Physios, University of Utah, Salt Lake City, Utah 84112, U.S.A. Abstract.- We demonstrate the applicability of SQUID-lattice relaxation times. The very high sensitivity of a SQUID magne- tometer makes it an ideal instrument for every

Boyer, Edmond

433

Pax6 in the sepiolid squid Euprymna scolopes: evidence for a role in eye, sensory organ and brain development  

E-print Network

Pax6 in the sepiolid squid Euprymna scolopes: evidence for a role in eye, sensory organ and brain of a Pax6 orthologue from the sepiolid squid Euprymna scolopes and its developmental expression pattern Elsevier Science Ireland Ltd. All rights reserved. Keywords: Pax6; Squid; Euprymna scolopes; Eye; Sensory

McFall-Ngai, Margaret

434

A YBCO RF-squid variable temperature susceptometer and its applications  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

435

Ordinary SQUID interferometers and superfluid helium matter wave interferometers: The role of quantum fluctuations  

SciTech Connect

When comparing the operation of a superfluid helium matter wave quantum interferometer (He SQUID) with that of an ordinary direct-current quantum interferometer (dc SQUID), we estimate their resolution limitation that correspond to quantum fluctuations. An alternative mode of operation of the interferometer as a unified macroquantum system is considered.

Golovashkin, A. I.; Zherikhina, L. N., E-mail: zherikh@sci.lebedev.ru; Tskhovrebov, A. M. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Izmailov, G. N.; Ozolin, V. V. [Moscow Aviation Institute (State Technical University) (Russian Federation)

2010-08-15

436

THE EVOLUTIONARY ECOLOGY OF A SEPIOLID SQUID-VIBRIO ASSOCIATION: FROM CELL TO ENVIRONMENT  

E-print Network

THE EVOLUTIONARY ECOLOGY OF A SEPIOLID SQUID-VIBRIO ASSOCIATION: FROM CELL TO ENVIRONMENT S the evolution of these beneficial partnerships. The symbiosis between sepiolid squids (Cephalopoda: Sepiolidae, receptors, cell/cell interactions). Here, we examine the transition between these forces effecting

McFall-Ngai, Margaret

437

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

438

Multiplexed Readout of MMC Detector Arrays Using Non-hysteretic rf-SQUIDs  

NASA Astrophysics Data System (ADS)

Metallic magnetic calorimeters (MMCs) are widely used for various experiments in fields ranging from atomic and nuclear physics to X-ray spectroscopy, laboratory astrophysics or material science. Whereas in previous experiments single pixel detectors or small arrays have been used, for future applications large arrays are needed. Therefore, suitable multiplexing techniques for MMC arrays are currently under development. A promising approach for the readout of large arrays is the microwave SQUID multiplexer that employs non-hysteretic rf-SQUIDs to create a frequency shift of high resonators that is in accordance with the detector signal and that can be monitored by using standard microwave measurement techniques. In this paper we discuss the design of a recently developed and fabricated 64 pixel detector array with integrated microwave SQUID multiplexer that was produced to test the suitability of this readout technique. The characterization of dc-SQUIDs with virtually identical washer design compared to the rf-SQUIDs of the SQUID multiplexer revealed that the crucial SQUID parameters such as the critical current of the Josephson junctions or the washer inductance are close to the design values and anticipates a successful operation of the SQUID multiplexer.

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

2014-08-01

439

A Monoclonal Antibody Against Kinesin Inhibits Both Anterograde and Retrograde Fast Axonal Transport in Squid Axoplasm  

Microsoft Academic Search

One of our monoclonal antibodies against the heavy chain of bovine kinesin (H2) also recognized the heavy chain of squid kinesin. The immunofluorescence pattern of H2 in axoplasm was similar to that seen in mammalian cells with antibodies specific for kinesin light and heavy chains, indicating that squid kinesin is also concentrated on membrane-bounded organelles. Although kinesin is assumed to

Scott T. Brady; K. Kevin Pfister; George S. Bloom

1990-01-01

440

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.

441

Multichannel SQUID System With Integrated Magnetic Shielding for Magnetocardiography of Mice  

Microsoft Academic Search

A multichannel low transition temperature SQUID magnetometer system with integrated superconducting magnetic shielding is described, which is intended for recording the magnetocardiogram (MCG) of mice in a biolaboratory environment. The Dewar has a horizontal warm bore surrounded by a superconducting niobium shield. The mouse is situated in the center of the warm bore close to the SQUID magnetometers while its

R.. Ackermann; F.. Wiekhorst; A.. Beck; D.. Gutkelch; F.. Ruede; A.. Schnabel; U.. Steinhoff; D.. Drung; J.. Beyer; C.. Assmann; L.. Trahms; H.. Koch; T.. Schurig; R.. Fischer; M.. Bader; H.. Ogata; H.. Kado

2007-01-01

442

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

NASA Technical Reports Server (NTRS)

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

Lu, D. F.

1995-01-01

443

Stochastic resonance in an RF SQUID with shunted ScS junction  

NASA Astrophysics Data System (ADS)

Using a point (superconductor-constriction-superconductor, ScS) contact in a single-Josephson-junction superconducting quantum interference device (RF SQUID) provides stochastic resonance conditions at any arbitrary small value of loop inductance and contact critical current, unlike SQUIDs with more traditional tunnel (superconductor-insulator-superconductor, SIS) junctions. This is due to the unusual potential energy of the ScS RF SQUID which always has a barrier between two wells, thus making the device bistable. This paper presents the results of a numerical simulation of the stochastic dynamics of the magnetic flux in an ScS RF SQUID loop affected by band-limited white Gaussian noise and low-frequency sine signals of small and moderate amplitudes. The difference in stochastic amplification of RF SQUID loops incorporating ScS and SIS junctions is discussed.

Turutanov, O. G.; Golovanevskiy, V. A.; Lyakhno, V. Yu.; Shnyrkov, V. I.

2014-02-01

444

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

E-print Network

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) allows for a substantially larger flux-locked loop bandwidth as compared to a SQUID flux-locked loop that includes a room temperature amplifier. The bandwidth, linearity, noise performance, and dynamic range of the LISA are sufficient for its use in our target application: the multiplexed readout of transition-edge sensor bolometers.

Lanting, T; Spieler, H; Lee, A T; Yamamoto, Y

2009-01-01

445

Quantum entanglement of two flux qubits induced by an auxiliary SQUID  

E-print Network

We revisit a theoretical scheme to create quantum entanglement of two three-levels superconducting quantum interference devices (SQUIDs) with the help of an auxiliary SQUID. In this scenario, two three-levels systems are coupled to a quantized cavity field and a classical external field and thus form dark states. The quantum entanglement can be produced by a quantum measurement on the auxiliary SQUID. Our investigation emphasizes the quantum effect of the auxiliary SQUID. For the experimental feasibility and accessibility of the scheme, we calculate the time evolution of the whole system including the auxiliary SQUID. To ensure the efficiency of generating quantum entanglement, relations between the measurement time and dominate parameters of the system are analyzed according to detailed calculations.

Shi, T

2006-01-01

446

Planar-type MgB2 SQUIDs utilizing a multilayer process  

NASA Astrophysics Data System (ADS)

We report planar-type MgB2 DC SQUIDs fabricated using a multilayer process. The SQUIDs employed sandwich-type MgB2/MgO/MgB2 Josephson junctions and a MgB2 wiring layer. The SQUIDs showed large voltage modulation above 500 ?V at 15 K and operated in a broad temperature range from 15 to 37 K with a transfer function as high as 2.3 mV/?0. The minimum SQUID noise was measured at 26 K in a cryocooler, yielding a white noise around 10 ??0/Hz1/2 and 1/f corner frequency near 10 Hz. The result demonstrates great promise of MgB2 SQUIDs for practical applications.

Cunnane, Daniel; Galan, Elias; Chen, Ke; Xi, X. X.

2013-11-01

447

Quantum entanglement of two flux qubits induced by an auxiliary SQUID  

E-print Network

We revisit a theoretical scheme to create quantum entanglement of two three-levels superconducting quantum interference devices (SQUIDs) with the help of an auxiliary SQUID. In this scenario, two three-levels systems are coupled to a quantized cavity field and a classical external field and thus form dark states. The quantum entanglement can be produced by a quantum measurement on the auxiliary SQUID. Our investigation emphasizes the quantum effect of the auxiliary SQUID. For the experimental feasibility and accessibility of the scheme, we calculate the time evolution of the whole system including the auxiliary SQUID. To ensure the efficiency of generating quantum entanglement, relations between the measurement time and dominate parameters of the system are analyzed according to detailed calculations.

T. Shi; Z. Song

2006-11-01

448

High- Tc dc SQUID readout electronics with low noise and high bandwidth  

NASA Astrophysics Data System (ADS)

Using AD797 low noise op amps and 2SA1048 low noise transistors, we have developed a composite preamplifier for use in dc SQUID readout electronics. This preamplifier has a small dc drift and super low noise at high frequencies. The equivalent input voltage noise of the preamplifier is about 0.35 nV/?Hz from 100 kHz to 10 MHz. Using this preamplifier, we developed dc SQUID readout electronics having low noise and high bandwidth. Used with a 3 mm 2 high- Tc dc SQUID, the white flux noise was about 18 ?? 0/?Hz above 100 kHz and the FLL bandwidth was about 2 MHz. This readout electronics can be used for the applications of SQUID-based NDE and SQUID-based NQR.

He, D. F.; Itozaki, H.

2006-10-01

449

SQUID magnetometry from nanometer to centimeter length scales  

NASA Astrophysics Data System (ADS)

Information stored in magnetic fields plays an important role in everyday life. This information exists over a remarkably wide range of sizes, so that magnetometry at a variety of length scales can extract useful information. Examples at centimeter to millimeter length scales include measurement of spatial and temporal character of fields generated in the human brain and heart, and active manipulation of spins in the human body for non-invasive magnetic resonance imaging (MRI). At micron length scales, magnetometry can be used to measure magnetic objects such as flux qubits; at nanometer length scales it can be used to study individual magnetic domains, and even individual spins. The development of Superconducting QUantum Interference Device (SQUID) based magnetometer for two such applications, in vivo prepolarized, ultra-low field MRI of humans and dispersive readout of SQUIDs for micro- and nanoscale magnetometry, are the focus of this thesis. Conventional MRI has developed into a powerful clinical tool for imaging the human body. This technique is based on nuclear magnetic resonance of protons with the addition application of three-dimensional magnetic field gradients to encode spatial information. Most clinical MRI systems involve magnetic fields generated by superconducting magnets, and the current trend is to higher magnetic fields than the widely used 1.5-T systems. Nonetheless, there is ongoing interest in the development of less expensive imagers operating at lower fields. The prepolarized, SQUID detected ultra-low field MRI (ULF MRI) developed by the Clarke group allows imaging in very weak fields (typically 132 muT, corresponding to a resonant frequency of 5.6 kHz). At these low field strengths, there is enhanced contrast in the longitudinal relaxation time of various tissue types, enabling imaging of objects which are not visible to conventional MRI, for instance prostate cancer. We are currently investigating the contrast between normal and cancerous prostate tissue in ex vivo prostate specimens in collaboration with the UCSF Genitourinary Oncology/Prostate SPORE Tissue Core. In characterizing pairs of nominally normal and cancerous tissue, we measure a marked difference in the longitudinal relaxation times, with an average value of cancerous tissue 0.66 times shorter than normal prostate tissue. However, in vivo imaging is required to definitively demonstrate the feasibility of ULF MR imaging of prostate cancer. To that end, we have worked to improve the performance of the system to facilitate human imaging. This is accomplished by increasing the prepolarizing field amplitude, and minimizing magnetic noise in the SQUID detector. We have achieved polarizing fields as high as 150 mT and SQUID effective field noise below 1 fT Hz-1/2, enabling us to demonstrate proof-of-principle in vivo images of the human forearm with 2 x 2 x 10 mm3 resolution in 6 minutes. On a much smaller spatial scale, there is currently fundamental and technological interest in measuring and manipulating nanoscale magnets, particularly in the quantum coherent regime. The observation of the dynamics of such systems requires a magnetometer with not only exceptional sensitivity but also high gain, wide bandwidth and low backaction. We demonstrate a dispersive magnetometer consisting of a two-junction SQUID in parallel with an integrated, lumped-element capacitor. Input flux signals are encoded as a phase modulation of the microwave drive tone applied to the magnetometer, resulting in a single quadrature voltage signal. For strong drive power, the nonlinearity of the resonator results in quantum limited, phase sensitive parametric amplification of this signal. We have achieved a bandwidth of 20 MHz---approximately two orders of magnitude higher than dispersive devices of comparable sensitivity---with an effective flux noise of 0.29 muphi0 Hz-12 . This performance is in excellent agreement with our theoretical model.

Hatridge, Michael Jonathan

450

NEON: Contributing continental-scale long-term environmental data for the benefit of society  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is a NSF funded national investment in physical and information infrastructure. Large-scale environmental changes pose challenges that straddle environmental, economic, and social boundaries. As we develop climate adaptation strategies at the Federal, state, local, and tribal levels, accessible and usable data are essential for implementing actions that are informed by the best available information. NEON's goal is to enable understanding and forecasting of the impacts of climate change, land use change and invasive species on continental-scale ecology by providing physical and information infrastructure. The NEON framework will take standardized, long-term, coordinated measurements of related environmental variables at each of its 62 sites across the nation. These observations, collected by automated instruments, field crews, and airborne instruments, will be processed into more than 700 data products that are provided freely over the web to support research, education, and environmental management. NEON is envisioned to be an integral component of an interoperable ecosystem of credible data and information sources. Other members of this information ecosystem include Federal, commercial, and non-profit entities. NEON is actively involved with the interoperability community via forums like the Foundation for Earth Science Information Partners and the USGS Community for Data Integration in a collective effort to identify the technical standards, best practices, and organizational principles that enable the emergence of such an information ecosystem. These forums have proven to be effective innovation engines for the experimentation of new techniques that evolve into emergent standards. These standards are, for the most part, discipline agnostic. It is becoming increasingly evident that we need to include socio-economic and public health data sources in interoperability initiatives, because the dynamics of coupled natural-human systems cannot be understood in the absence of data about the human dimension. Another essential element is the community of tool and platform developers who create the infrastructure for scientists, educators, resource managers, and policy analysts to discover, analyze, and collaborate on problems using the diverse data that are required to address emerging large-scale environmental challenges. These challenges are very unlikely to be problems confined to this generation: they are urgent, compelling, and long-term problems that require a sustained effort to generate and curate data and information from observations, models, and experiments. NEON's long-term national physical and information infrastructure for environmental observation is one of the cornerstones of a framework that transforms science and information for the benefit of society.

Wee, B.; Aulenbach, S.

2011-12-01

451

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.

452

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

453

Spitzer Finds Cosmic Neon and Sulfur's Sweet Spot  

NASA Astrophysics Data System (ADS)

Elemental abundances are the fossil remnants of the life history of a galaxy. Abundance ratios indicate the effects of star formation and the release of nuclear processed heavy elements via planetary nebulae and supernovae, plus other mechanisms. By deriving the elemental abundances and judicious modeling, astronomers are able to determine the relative importance of these processes in the chemical evolution of a galaxy. Modeling requires the input of nucleosynthetic yields from stellar evolution and supernova calculations. Since most fusion reaction rates cannot be measured in any earthly laboratory, the observed elemental ratios provide good tests of fusion reaction rate calculations. This proposal addresses the means by which we determine elemental abundances. H II regions are the prime laboratory for the measurement of the most abundant elements- He, C, N, O, Ne, S, and Ar, (usually with respect to hydrogen)- because these elements have strong lines in the ionization states produced by the Lyman continuum photons from massive O-stars. With Spitzer's Infrared Spectrograph (IRS) Short-High (SH) module (wavelength range 9.9-19.6 microns), we have the unique opportunity to measure lines from the two ions of neon (Ne+ & Ne++) and the two most abundant ions of sulfur (S++ & S+3) that are seen in H II regions: [Ne II] 12.8, [Ne III] 15.6, [S III] 18.7, and [S IV] 10.5 microns. These co-spatial/coeval spectra enable unprecedented accuracy for the measurement of these four lines and the estimate of the Ne/S abundance ratio. In Spitzer Cycles 1, 2, and 4 we measured respectively the Ne/S ratios for the galaxies M83 (a barred spiral), M33 (a local group spiral), and NGC 6822 (a local group dwarf irregular). With other GO programs, in Cycle 1 we measured the abundances in two Milky Way H II regions & the Arched Filaments in the Galactic Center, and in Cycle 5, the Orion Nebula. We propose to estimate the Ne and S abundances in many more H II regions, both extragalactic and Galactic, using archival Spitzer IRS-SH spectra. We wish to determine how much the true Ne/S ratio varies. There is a hint from our prior data that there is some metallicity dependence. We will also measure the abundances of other ions, including Si+, Fe+, and Fe++, for those sources that were also measured with the Spitzer IRS Long-High (LH) module (wavelength range 19-37 microns). The abundant elements Si and Fe are refractory and depleted onto dust grains; we will estimate the depletion from these gas-phase measurements. The LH also covers the [S III] 33.5 micron line that together with the 18.7 line provides a diagnostic of electron density. In addition to the nebular abundances, geometry, and density structure, photoionization models of H II region require input of an ionizing spectral energy distribution (SED) as predicted by stellar atmosphere models. Our four 'major' Spitzer program lines probe ions with ionization potentials 21.6 (Ne+), 41.0 (Ne++), 23.3 (S++), and 34.8 eV (S+3); thus, the ionic ratios derived from the observations are sensitive to this part of the ionizing SED, which often differs considerably between the stellar atmosphere models. In support of this project, Co-I Pauldrach will compute an extensive new set of O-star atmosphere models that use different metallicities than the Solar values used previously. This is a needed advance in order to do more refined comparisons between predictions and observation. The Spitzer-derived ionic ratios we have studied appear to provide a strong discriminant between the various state-of-the-art atmosphere models. Our work will help test/validate which set appears to be most realistic, and provide feedback to that community. Using the best SEDs provides the most reliable photoionization models for H II regions.

Rubin, Robert

454

Journal of Low Temperature Physics, Vol. 110, Nos. 5/6, 1998 The Superfluid 4He Analog of the RF SQUID  

E-print Network

SQUID K. Schwab, N. Bruckner, and Richard Packard Physics Department, University of California, Berkeley, fabrication, and performance of a superfluid 4He device which is the analog of the superconducting RF SQUID. INTRODUCTION This paper describes a superfluid analog of the superconducting RF SQUID.1 Whereas an RF SQUID

Packard, Richard E.

455

Sensitive RF-SQUIDs and magnetometers operating at 77 K  

Microsoft Academic Search

Large 6-mm×6-mm and 8-mm×8-mm flux-focusing washer structures with inductances LS between 25 pH and 500 pH were fabricated from epitaxial, c-axis YBa2Cu3O7 films. Double step-edge junctions having a low 1\\/f noise were incorporated in these washers to form RF-SQUIDs (superconducting quantum interference devices). A high tank circuit frequency near 150 MHz was chosen to reduce noise and improve the sensitivity

Y. Zhang; M. Miick; K. Herrmann; W. Zander; A. i. Braginski; C. Heiden

1993-01-01

456

Effect of the magnetic-flux variations on SQUID stability  

SciTech Connect

The oscillation dynamics of a nonhysteretic, one-contact superconducting quantum interferometer under low-frequency modulation of an external magnetic flux is studied. It is shown that even in the case of adiabatic, equilibrium, and nonhysteretic operation modes of a superconducting ring enclosed by a weak link, there can appear chaotic oscillations. The conditions of chaos arising are considered analytically and numerically; mechanisms and destruction scenarios of periodic oscillations are studied. The stochastic instability could impose limitations on the increase in sensitivity of nonhysteretic SQUIDs, which was earlier predicted to be high enough.

Bulgakov, S.A.; Ryabov, V.B.; Shnyrkov, V.I.; Vavriv, D.M. (Inst. of Radio Astronomy, Kharkov (Ukrainian SSR))

1991-06-01

457

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

458

Flying radio frequency undulator  

NASA Astrophysics Data System (ADS)

A concept for the room-temperature rf undulator, designed to produce coherent X-ray radiation by means of a relatively low-energy electron beam and pulsed mm-wavelength radiation, is proposed. The "flying" undulator is a high-power short rf pulse co-propagating together with a relativistic electron bunch in a helically corrugated waveguide. The electrons wiggle in the rf field of the -1st spatial harmonic with the phase velocity directed in the opposite direction in respect to the bunch velocity, so that particles can irradiate high-frequency Compton's photons. A high group velocity (close to the speed of light) ensures long cooperative motion of the particles and the co-propagating rf pulse.

Kuzikov, S. V.; Savilov, A. V.; Vikharev, A. A.

2014-07-01

459

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

E-print Network

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- and intermediate-mass stars (LIMS), as well as the currently hotly disputed solar Ne/O abundance ratio. Through the comparisons, we find that neon abundance and Ne/O ratio increase with increasing oxygen abundance in both types of nebulae, with positive correlation coefficients larger than 0.75. The correlations suggest different enrichment mechanisms for oxygen and neon in the ISM, in the sense that the growth of neon is delayed compared to oxygen. The differences of abundances between PNe and HII regions, are mainly attributed to the results of nucleosynthesis and dredge-up processes that occurred in the progenitor stars of PNe. We find that both these alpha-elements are significantly enriched at low metallicity (initial oxygen abundance oxygen in intermediate mass stars (IMS) of low initial metallicities and in more massive stars, a conjecture that requires verification by further theoretical studies. This result also strongly suggests that both the solar neon abundance and the Ne/O ratio should be revised upwards by ~0.22 dex from the Asplund, Grevesse & Sauval values or by ~0.14 dex from the Grevesse & Sauval values.

W. Wang; X. -W. Liu

2008-06-13

460

Angle-resolved Auger electron spectra induced by neon ion impact on aluminum  

NASA Technical Reports Server (NTRS)

Auger electron emission from aluminum bombarded with 1 to 5 keV neon ions was studied by angle-resolved electron spectroscopy. The position and shape of the spectral features depended on the incident ion energy, angle of ion incidence, and electron take-off angle with respect to the aluminum surface. These spectral dependencies were interpreted in terms of the Doppler shift given to the Auger electron velocity by the excited atom ejected into the vacuum. For oblique ion incidence it is concluded that a flux of high energy atoms are ejected in a direction close to the projection of the ion beam on the target surface. In addition, a new spectral feature was found and identified as due to Auger emission from excited neon in the aluminum matrix.

Pepper, S. V.; Aron, P. R.

1986-01-01

461

Up to fourth virial coefficients from simple and efficient internal-coordinate sampling: Application to neon  

NASA Astrophysics Data System (ADS)

A simple and efficient internal-coordinate importance sampling protocol for the Monte Carlo computation of (up to fourth-order) virial coefficients bar{B}_n of atomic systems is proposed. The key feature is a multivariate sampling distribution that mimics the product structure of the dominating pairwise-additive parts of the bar{B}_n. This scheme is shown to be competitive over routine numerical methods and, as a proof of principle, applied to neon: The second, third, and fourth virial coefficients of neon as well as equation-of-state data are computed from ab initio two- and three-body potentials; four-body contributions are found to be insignificant. Kirkwood-Wigner quantum corrections to first order are found to be crucial to the observed agreement with recent ab initio and experimental reference data sets but are likely inadequate at very low temperatures.

Wiebke, Jonas; Pahl, Elke; Schwerdtfeger, Peter

2012-07-01

462

Branches of 33S(p,?)34Cl at Oxygen-Neon Nova Temperatures  

E-print Network

Recent simulations of classical novae on oxygen-neon white-dwarf stars indicate that the isotopic ratio 32S/33S has the potential to be a remarkable indicator of presolar grains of nova origin. The 33S(p,\\gamma)34Cl reaction influences this ratio directly by destroying 33S in novae. Additionally, \\beta-delayed \\gamma-rays from the metastable state of 34Cl (t_{1/2} = 32 min) have been suggested to be potential nova observables. We have measured the branches for known 33S(p,\\gamma)34Cl resonances that are activated at temperatures relevant to oxygen-neon novae. We provide the first reliable uncertainties on these branches and the first upper limits for several previously unmeasured branches.

B. M. Freeman; C. Wrede; B. G. Delbridge; A. Garcia; A. Knecht; A. Parikh; A. L. Sallaska

2011-05-02

463

Prediction of thermal acoustic oscillations (TAOs) in the CLAES solid CO2/neon system  

NASA Technical Reports Server (NTRS)

Results are presented of a study initiated to investigate the possibility that the existence of thermal acoustic oscillations (TAOs) in the Cryogenic Limb Atmospheric Etalon Spectrometer (CLAES) neon plumbing system ground configuration could be the cause of higher-than-predicted heat rates measured during thermal ground testing. Tests were conducted between warm boundary temperatures ranging from 40 to 100 K, which simulated the actual test conditions of the CLAES CO2/neon system. TAOs were observed between 6 and 106 Torr, which agreed with the analytical predictions, and verified the possible existence of TAOs in the CLAES system during ground testing. The presence of TAOs was eventually confirmed in the CLAES system during a subsequent thermal test and were determined to have caused the higher heat rates measured during the prior thermal test.

Spradley, I. E.; Yuan, S. W. K.

1991-01-01

464

Inhomogeneous gas model for electron mobility in high density neon gas  

E-print Network

Experimental studies of electron mobilities in Neon as a function of the gas density have persistently shown mobilities up to an order of magnitude smaller than expected and predicted. A previously ignored mechanism (gas in--homogeneity which is negligible in the thermal mobilities for He and other gases) is found to reproduce the observed Neon mobilities accurately and simply at five temperatures with just one variable parameter. Recognizing that a gas is not a homogeneous medium, a variation in local density combined with the quantum multi--scattering theory, shifts the energy and cross section -- which in turn changes the collision probability and finally the mobilities. A lower density where a momentum transfer interaction occurs moves the mobility strongly in the same direction as the anomalous experiments. By going backwards from the observed mobilities, the collision frequency at each temperature and density is made to reproduce the experimental data by looking for the local (as opposed to average) den...

Borghesani, A F

2002-01-01

465

Design study of steady-state 30-tesla liquid-neon-cooled magnet  

NASA Technical Reports Server (NTRS)

A design for a 30-tesla, liquid-neon-cooled magnet was reported which is capable of continuous operation. Cooled by nonboiling, forced-convection heat transfer to liquid neon flowing at 2.8 cu m/min in a closed, pressurized heat-transfer loop and structurally supported by a tapered structural ribbon, the tape-wound coils with a high-purity-aluminum conductor will produce over 30 teslas for 1 minute at 850 kilowatts. The magnet will have an inside diameter of 7.5 centimeters and an outside diameter of 54 centimeters. The minimum current density at design field will be 15.7 kA/sq cm.

Prok, G. M.; Brown, G. V.

1976-01-01

466

Up to fourth virial coefficients from simple and efficient internal-coordinate sampling: application to neon.  

PubMed

A simple and efficient internal-coordinate importance sampling protocol for the Monte Carlo computation of (up to fourth-order) virial coefficients ?B(n) of atomic systems is proposed. The key feature is a multivariate sampling distribution that mimics the product structure of the dominating pairwise-additive parts of the ?B(n). This scheme is shown to be competitive over routine numerical methods and, as a proof of principle, applied to neon: The second, third, and fourth virial coefficients of neon as well as equation-of-state data are computed from ab initio two- and three-body potentials; four-body contributions are found to be insignificant. Kirkwood-Wigner quantum corrections to first order are found to be crucial to the observed agreement with recent ab initio and experimental reference data sets but are likely inadequate at very low temperatures. PMID:22779666

Wiebke, Jonas; Pahl, Elke; Schwerdtfeger, Peter

2012-07-01

467

Flying qualities criteria for superaugmented aircraft  

NASA Technical Reports Server (NTRS)

An overview of Dryden superaugmented aircraft flying qualities research is presented. This includes F-8 digital fly by wire flight experiments, orbiter flying qualities, shuttle improvements, AFTI/F-16, flying qualities and control system alternatives, Vertical Motion Simulator Shuttle evaluation and Total in Flight Simulator pitch rate criteria.

Berry, D. T.

1984-01-01

468

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

SciTech Connect

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, the authors present their study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology.

Lu, D.F.; Fan, C.; Ruan, J.Z.; Han, S.G.; Wong, K.W.; Sun, G.F. [Kansas Univ., Lawrence, KS (United States)

1995-04-01

469

Effect of helium-neon and infrared laser irradiation on wound healing in rabbits  

Microsoft Academic Search

We examined the biostimulating effects of helium-neon laser radiation (HeNe; 632.8 nm), pulsed infrared laser radiation (IR; 904 nm), and the two combined on skin wound healing in New Zealand white rabbits. Seventy-two rabbits received either (1) no exposure, (2) 1.65 J\\/cm2 HeNe, (3) 8.25 J\\/cm2 pulsed IR, or (4) both HeNe and IR together to one of two dorsal

Berton Braverman; Robert J. McCarthy; Anthony D. Ivankovich; Danon E. Forde; Michael Overfield; Mahapna S. Bapna

1989-01-01

470

Numerical model of an ac plasma display panel cell in neon-xenon mixtures  

Microsoft Academic Search

We present a self-consistent 1D model of the discharge initiated in an ac plasma display panel cell. The model is based on a two-moments fluid description of electron and ion transport, coupled with Poisson’s equation, and with a set of kinetic equations characterizing the evolution of the population of excited states leading to UV emission in neon-xenon mixtures. Results are

J. Meunier; Ph. Belenguer; J. P. Boeuf

1995-01-01

471

Autoionization resonances in the neon isoelectronic sequence using relativistic multichannel quantum-defect theory  

NASA Astrophysics Data System (ADS)

Studies of 2 s ?n p autoionization resonances in the neon isoelectronic sequence using relativistic multichannel quantum-defect theory are reported. The relativistic random-phase approximation is used to calculate the quantum-defect parameters. The autoionization resonances are characterized using Fano resonance parameters. The results are compared with available experimental and theoretical data, and the behavior of the resonances as a function of Z is discussed.

Nrisimhamurty, M.; Aravind, G.; Deshmukh, P. C.; Manson, S. T.

2015-01-01

472

Measurement of the elastic scattering cross section of neutrons from argon and neon  

E-print Network

Background: The most significant source of background in direct dark matter searches are neutrons that scatter elastically from nuclei in the detector's sensitive volume. Experimental data for the elastic scattering cross section of neutrons from argon and neon, which are target materials of interest to the dark matter community, were previously unavailable. Purpose: Measure the differential cross section for elastic scattering of neutrons from argon and neon in the energy range relevant to backgrounds from (alpha,n) reactions in direct dark matter searches. Method: Cross-section data were taken at the Triangle Universities Nuclear Laboratory (TUNL) using the neutron time-of-flight technique. These data were fit using the spherical optical model. Results: The differential cross section for elastic scatting of neutrons from neon at 5.0 and 8.0 MeV and argon at 6.0 MeV was measured. Optical-model parameters for the elastic scattering reactions were determined from the best fit to these data. The total elastic scattering cross section for neon was found to differ by 6% at 5.0 MeV and 13% at 8.0 MeV from global optical-model predictions. Compared to a local optical-model for 40Ar, the elastic scattering cross section was found to differ from the data by 8% at 6.0 MeV. Conclusions: These new data are important for improving Monte-Carlo simulations and background estimates for direct dark matter searches and for benchmarking optical models of neutron elastic scattering from these nuclei.

S. MacMullin; M. Kidd; R. Henning; W. Tornow; C. R. Howell; M. Brown

2012-12-12

473

University of Virginia Physical Science SOL Activities: Neon Bulbs & Motion of Charge  

NSDL National Science Digital Library

This item is a lesson plan featuring the neon bulb, an object that can be lighted either by electric current or by static charge. Accompanied by detailed background information, this lesson promotes conceptual understanding of electron transfer. It includes printable data sheets for use in the physics classroom. No math is required. This lesson is part of a larger collection generated by the University of Virginia Department of Physics outreach program.

Morse, Robert

2006-11-07

474

Some properties of ionization waves of variety R in a neon glow discharge  

Microsoft Academic Search

The parameters of ther-ionization waves in a neon discharge were measured at two neutral gas temperatures (298°K and 77°K). The experimental results of the measurements of the artificially excitedr-ionization waves over the region of the homogeneous positive column in discharge tubes with different radius (from 0·5 cm to 1·2 cm) are reported. The results are arranged as simple functions of

V. Pe?ina

1969-01-01

475

Liquid-gas transition of neon in quasi-one-dimensional environments  

NASA Astrophysics Data System (ADS)

We characterize the behavior of a system of Ne20 atoms in a pure one-dimensional environment between 12 and 30 K by means of path integral Monte Carlo calculations. This is a reasonable model to describe neon absorbed inside a narrow carbon nanotube. When embedded in a bundle of those tubes, this quasi-one-dimensional system can undergo a liquid-gas phase transition if nanotubes are narrow and close enough.

Brualla, L.; Gordillo, M. C.

2003-08-01

476

K Shell Ionizations of Carbon, Nitrogen, Oxygen, Fluorine and Neon by Proton and Alpha Particle Bombardments  

Microsoft Academic Search

The K Auger electron spectra have been measured for carbon, nitrogen, oxygen, fluorine and neon excited by protons and alpha particles of 0.5-2.6 MeV. In comparison with the spectra obtained by electron impact, the satellite lines have grown more intensively as projectiles become heavier. This indicates the presence of a contribution of simultaneous L shell ionization. A quantitative analysis has

Naoto Kobayashi; Nobuhiro Maeda; Hiroshi Hori; Masakatsu Sakisaka

1976-01-01

477

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

478

SQUID-detected ultra-low field MRI  

NASA Astrophysics Data System (ADS)

MRI remains the premier method for non-invasive imaging of soft-tissue. Since the first demonstration of ULF MRI the trend has been towards ever higher magnetic fields. This is because the signal, and efficiency of Faraday detectors, increases with ever higher magnetic fields and corresponding Larmor frequencies. Nevertheless, there are many compelling reasons to continue to explore MRI at much weaker magnetic fields, the so-called ultra-low field or (ULF) regime. In the past decade many excellent proof-of-concept demonstrations of ULF MRI have been made. These include combined MRI and magnetoencephalography, imaging in the presence of metal, unique tissue contrast, and implementation in situations where a high magnetic field is simply impractical. These demonstrations have routinely used pulsed pre-polarization (at magnetic fields from ˜10 to 100 mT) followed by read-out in a much weaker (1-100 ?T) magnetic fields using the ultra-sensitive Superconducting Quantum Interference Device (SQUID) sensor. Even with pre-polarization and SQUID detection, ULF MRI suffers from many challenges associated with lower magnetization (i.e. signal) and inherently long acquisition times compared to conventional >1 T MRI. These are fundamental limitations imposed by the low measurement and gradient fields used. In this review article we discuss some of the techniques, potential applications, and inherent challenges of ULF MRI.

Espy, Michelle; Matlashov, Andrei; Volegov, Petr

2013-03-01

479

SQUID-detected ultra-low field MRI  

NASA Astrophysics Data System (ADS)

MRI remains the premier method for non-invasive imaging of soft-tissue. Since the first demonstration of ULF MRI the trend has been towards ever higher magnetic fields. This is because the signal, and efficiency of Faraday detectors, increases with ever higher magnetic fields and corresponding Larmor frequencies. Nevertheless, there are many compelling reasons to continue to explore MRI at much weaker magnetic fields, the so-called ultra-low field or (ULF) regime. In the past decade many excellent proof-of-concept demonstrations of ULF MRI have been made. These include combined MRI and magnetoencephalography, imaging in the presence of metal, unique tissue contrast, and implementation in situations where a high magnetic field is simply impractical. These demonstrations have routinely used pulsed pre-polarization (at magnetic fields from ?10 to 100 mT) followed by read-out in a much weaker (1-100 ?T) magnetic fields using the ultra-sensitive Superconducting Quantum Interference Device (SQUID) sensor. Even with pre-polarization and SQUID detection, ULF MRI suffers from many challenges associated with lower magnetization (i.e. signal) and inherently long acquisition times compared to conventional >1 T MRI. These are fundamental limitations imposed by the low measurement and gradient fields used. In this review article we discuss some of the techniques, potential applications, and inherent challenges of ULF MRI.

Espy, Michelle; Matlashov, Andrei; Volegov, Petr

2013-04-01

480

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 mm 2 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

481

SQUID-Detected In Vivo MRI at Microtesla Magnetic Fields  

SciTech Connect

We use a low transition temperature (T{sub c}) Super-conducting Quantum Interference Device (SQUID) to perform in vivo magnetic resonance imaging (MRI) at magnetic fields around 100 microtesla, corresponding to proton Larmor frequencies of about 5 kHz. In such low fields, broadening of the nuclear magnetic resonance lines due to inhomogeneous magnetic fields and susceptibility variations of the sample are minimized, enabling us to obtain high quality images. To reduce environmental noise the signal is detected by a second-order gradiometer, coupled to the SQUID, and the experiment is surrounded by a 3-mm thick Al shield. To increase the signal-to-noise ratio (SNR), we prepolarize the samples in a field up to 100 mT. Three-dimensional images are acquired in less than 6 minutes with a standard spin-echo phase-encoding sequence. Using encoding gradients of {approx}100 {micro}T/m we obtain three-dimensional images of bell peppers with a resolution of 2 x 2 x 8 mm{sup 3}. Our system is ideally suited to acquiring images of small, peripheral parts of the human body such as hands and arms. In vivo images of an arm, acquired at 132 {micro}T, show 24-mm sections of the forearm with a resolution of 3 x 3 mm{sup 2} and a SNR of 10. We discuss possible applications of MRI at these low magnetic fields.

Moble, Michael; Myers, Whittier R; Lee, SeungKyun; Kelso, Nathan; Hatridge, Michael; Pines, Alexander; Clarke, John

2005-06-01

482

Neural control of tuneable skin iridescence in squid.  

PubMed

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. PMID:22896651

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

2012-10-22

483

Hierarchical, self-similar structure in native squid pen.  

PubMed

The structure of native squid pen (gladius) was investigated in two different species on different length scales. By combining microscopy, atomic force microscopy (AFM), and X-ray diffraction, the experiments probed length scales from millimetres down to nanometres. The gladii showed a hierarchical, self-similar structure in the optical experiments with fibres of different size oriented along the long axis of the gladius. The fibre-like structure was reproduced at the nanoscale in AFM measurements and fibres with diameters of 500 ?m, 100 ?m, 10 ?m, 2 ?m and 0.2 ?m were observed. Their molecular structure was determined using X-ray diffraction. In the squid gladius, the chitin molecules are known to form nano-crystallites of monoclinic lattice symmetry wrapped in a protein layer, resulting in ?-chitin nano-fibrils. Signals corresponding to the ?-coil protein phase and ?-chitin crystallites were observed in the X-ray experiments and their orientation with respect to the fibre-axis was determined. The size of a nano-fibril was estimated from the X-ray experiments to be about 150 × 300 Å. About 100 of these nano-fibrils are needed to form a 0.2 ?m thick micro-fibre. We found that the molecular structure is highly anisotropic with ?90% of the ?-coils and ?-chitin crystallites oriented along the fibre-axis, indicating a strong correlation between the macroscale structure and molecular orientation. PMID:24957525

Yang, Fei-Chi; Peters, Robert D; Dies, Hannah; Rheinstädter, Maikel C

2014-08-14

484

Impact of SQUIDs on functional imaging in neuroscience  

NASA Astrophysics Data System (ADS)

This paper provides an overview on the basic principles and applications of magnetoencephalography (MEG), a technique that requires the use of many SQUIDs and thus represents one of the most important applications of superconducting electronics. Since the development of the first SQUID magnetometers, it was clear that these devices could be used to measure the ultra-low magnetic signals associated with the bioelectric activity of the neurons of the human brain. Forty years on from the first measurement of magnetic alpha rhythm by David Cohen, MEG has become a fundamental tool for the investigation of brain functions. The simple localization of cerebral sources activated by sensory stimulation performed in the early years has been successively expanded to the identification of the sequence of neuronal pool activations, thus decrypting information of the hierarchy underlying cerebral processing. This goal has been achieved thanks to the development of complex instrumentation, namely whole head MEG systems, allowing simultaneous measurement of magnetic fields all over the scalp with an exquisite time resolution. The latest trends in MEG, such as the study of brain networks, i.e. how the brain organizes itself in a coherent and stable way, are discussed. These sound applications together with the latest technological developments aimed at implementing systems able to record MEG signals and magnetic resonance imaging (MRI) of the head with the same set-up pave the way to high performance systems for brain functional investigation in the healthy and the sick population.

Della Penna, Stefania; Pizzella, Vittorio; Romani, Gian Luca

2014-04-01

485

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. PMID:22896651

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

2012-01-01

486

Scanning SQUID microscopy of local superconductivity in inhomogeneous combinatorial ceramics.  

PubMed

Although combinatorial solid-state chemistry promises to be an efficient way to search for new superconducting compounds, the problem of determining which compositions are strongly diamagnetic in a mixed-phase sample is challenging. By means of reactions in a system of randomly mixed starting components (Ca, Sr, Ba, La, Y, Pb, Bi, Tl, and Cu oxides), samples were produced that showed an onset of diamagnetic response above 115?K in bulk measurements. Imaging of this diamagnetic response in ceramic samples by scanning SQUID microscopy (SSM) revealed local superconducting areas with sizes down to as small as the spatial resolution of a few micrometers. In addition, locally formed superconducting matter was extracted from mixed-phase samples by magnetic separation. The analysis of single grains (d<80??m) by X-ray diffraction, elemental analysis, and bulk SQUID measurements allowed Tl2Ca3Ba2Cu4O12, TlCaBaSrCu2O(7-?), BaPb(0.5)Bi(0.25)Tl(0.25)O(3-?), TlBa2Ca2Cu3O9, Tl2Ba2CaCu2O8, and YBa2Cu3O7 phases to be identified. SSM, in combination with other diagnostic techniques, is therefore shown to be a useful instrument to analyze inhomogeneous reaction products in the solid-state chemistry of materials showing magnetic properties. PMID:25303177

Iranmanesh, Mitra; Stir, Manuela; Kirtley, John R; Hulliger, Jürg

2014-11-24

487

Dynamics of the Internal Water Molecules in Squid Rhodopsin  

PubMed Central

Understanding the mechanism of G-protein coupled receptors action is of major interest for drug design. The visual rhodopsin is the prototype structure for the family A of G-protein coupled receptors. Upon photoisomerization of the covalently bound retinal chromophore, visual rhodopsins undergo a large-scale conformational change that prepares the receptor for a productive interaction with the G-protein. The mechanism by which the local perturbation of the retinal cis-trans isomerization is transmitted throughout the protein is not well understood. The crystal structure of the visual rhodopsin from squid solved recently suggests that a chain of water molecules extending from the retinal toward the cytoplasmic side of the protein may play a role in the signal transduction from the all-trans retinal geometry to the activated receptor. As a first step toward understanding the role of water in rhodopsin function, we performed a molecular dynamics simulation of squid rhodopsin embedded in a hydrated bilayer of polyunsaturated lipid molecules. The simulation indicates that the water molecules present in the crystal structure participate in favorable interactions with side chains in the interhelical region and form a persistent hydrogen-bond network in connecting Y315 to W274 via D80. PMID:19348742

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

2009-01-01

488

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

NASA Astrophysics Data System (ADS)

We will present results which show lasing on the 3p yields 3s (J equals 0 yields 1) transition in neon-like chromium (Z equals 24), iron (Z equals 24), iron (Z equals 26), and nickel (Z equals 28) at 285, 255, and 231 angstroms respectively. This destroys the myth of titanium being unique and makes highly unlikely that the previously mentioned photo-pumping mechanism is playing a significant role in the titanium laser. The chromium, iron, and nickel experiments all require a prepulse in order to lase and our calculations suggest that the prepulse is an exciting new way to create a uniform low density plasma when illuminating a thick slab target. This allows the proper conditions for gain and laser propagation for low Z neon-like ions and may also be applicable to other systems such as low Z nickel-like ions. We also will present experiments done on other low-Z materials and offer an explanation as to how the hyperfine effect is destroying the gain of neon-like ions with odd Z.

Nilsen, Joseph; MacGowan, Brian J.; Da Silva, Luiz B.; Moreno, Juan C.; Koch, Jeffrey A.; Scofield, James H.

1994-02-01

489

Infrared spectrum of the NH4-d(n)+ cation trapped in solid neon.  

PubMed

The NH4+ cation has been stabilized in solid neon in sufficient concentration for the identification of both of its infrared-active vibrational fundamentals, which appear within a few wavenumbers of the gas-phase band centers. Systematic alteration of the concentrations and positions of introduction of NH3 and H2 in the discharge sampling experiments demonstrated that the highest yield of NH4+ resulted when both the NH3 and the H2 were introduced downstream from a discharge through pure neon. In this configuration, each of these molecules can be ionized by excited neon atoms and their resonance radiation (16.6 eV to 16.85 eV), but fragmentation is minimized. Both infrared-active vibrational fundamentals of ND4+ and several fundamentals of each of the partially deuterium-substituted isotopomers of NH4+ were also identified. Evidence is presented for complexation of NH4+ with an H atom or with one or more H2 molecules. PMID:19791360

Jacox, Marilyn E; Thompson, Warren E

2005-03-01

490

Neon in condensed phase: quantitative calculations of structural, thermodynamic and transport properties from pure theory  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulations are performed with a new ab initio neon—neon pair potential for pressures between 20 and 1000 MPa and temperatures between 100 and 600 K in the supercritical phase as well as for a point in the liquid phase of neon. Many properties, such as the pair distribution function g, the enthalpy H, the internal energy U, the molar heat capacities CV,m and CP,m, the speed of sound c, the adiabetic and isothermal compressibilities ? S and ? T, the thermal pressure coefficient ? V, the differential Joule-Thompson coefficient ?, the self-diffusion coefficient D, the thermal conductivity ? and the shear viscosity ?, are calculated and compared to the values obtained with a previous ab initio potential, to see the influence of the improvement in the quantum chemical calculation of the potential curve on the different properties. The typical deviations from experimental values, where available, are below 5% in the supercritical state. For several properties where experimental data are not available the calculated values give reliable predictions. For the liquid the errors are much larger, partially due to quantum effects, but probably also due to the stronger influence of the neglected many-body interactions and of the remaining errors in the two-particle potential.

Eggenberger, Rolf; Huber, Hanspeter; Welker, Marc

1994-10-01

491

PRESOLAR GRAINS FROM NOVAE: EVIDENCE FROM NEON AND HELIUM ISOTOPES IN COMET DUST COLLECTIONS  

SciTech Connect

Presolar grains in meteorites and interplanetary dust particles carry non-solar isotopic signatures pointing to origins in supernovae, giant stars, and possibly other stellar sources. There have been suggestions that some of these grains condensed in the ejecta of classical nova outbursts, but the evidence is ambiguous. We report neon and helium compositions in particles captured on stratospheric collectors flown to sample materials from comets 26P/Grigg-Skjellerup and 55P/Tempel-Tuttle that point to condensation of their gas carriers in the ejecta of a neon (ONe) nova. The absence of detectable {sup 3}He in these particles indicates space exposure to solar wind irradiation of a few decades at most, consistent with origins in cometary dust streams. Measured {sup 4}He/{sup 20}Ne, {sup 20}Ne/{sup 22}Ne, {sup 21}Ne/{sup 22}Ne, and {sup 20}Ne/{sup 21}Ne isotope ratios, and a low upper limit on {sup 3}He/{sup 4}He, are in accord with calculations of nucleosynthesis in neon nova outbursts. Of these, the uniquely low {sup 4}He/{sup 20}Ne and high {sup 20}Ne/{sup 22}Ne ratios are the most diagnostic, reflecting the large predicted {sup 20}Ne abundances in the ejecta of such novae. The correspondence of measured Ne and He compositions in cometary matter with theoretical predictions is evidence for the presence of presolar grains from novae in the early solar system.

Pepin, Robert O.; Palma, Russell L. [Department of Physics, University of Minnesota, Minneapolis, MN 55455 (United States); Gehrz, Robert D. [Department of Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Starrfield, Sumner, E-mail: pepin001@umn.edu [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)

2011-12-01

492

Comprehensive Study of Neon HXR and SXR Emitted from APF Plasma Focus Device  

NASA Astrophysics Data System (ADS)

Experimental results related to HXR and SXR properties of Neon plasma on the APF plasma focus device is presented. The experiments were carried on over a wide range of neon pressure and at voltages 11, 12 and 13 kV using plastic scintillator (NE102A) coupled with high gain PMT and six filtered photo PIN diodes. For the charging voltages of 11-13 kV with 2.17-3.04 kJ stored energy, the optimum operating pressure in neon is found to be in the range of 3.5-5 torr and the highest HXR emission was observed in the pressure of 5 torr at the voltage 13 kV and the maximum average HXR production is (9.84 ± 0.59) ×10-7 volt sec. The behavior of SXR intensities were registered by different filters and it was found out that Al-Mylar 6 ?m and Cu 10 ?m has the highest and lowest amount of X-ray transmission.

Baghdadi, R.; Etaati, G. R.; Habibi, M.; Amrollahi, R.; Roomi, A.

2011-12-01

493

Development of an image processing system in splendid squid quality classification  

NASA Astrophysics Data System (ADS)

Agricultural products typically exhibit high variance in quality characteristics. To assure customer satisfaction and control manufacturing productivity, quality classification is necessary to screen off defective items and to grade the products. This article presents an application of image processing techniques on squid grading and defect discrimination. A preliminary study indicated that surface color was an efficient determinant to justify quality of splendid squids. In this study, a computer vision system (CVS) was developed to examine the characteristics of splendid squids. Using image processing techniques, squids could be classified into three different quality grades as in accordance with an industry standard. The developed system first sifted through squid images to reject ones with black marks. Qualified squids were graded on a proportion of white, pink, and red regions appearing on their bodies by using fuzzy logic. The system was evaluated on 100 images of squids at different quality levels. It was found that accuracy obtained by the proposed technique was 95% compared with sensory evaluation of an expert.

Masunee, Niyada; Chaiprapat, Supapan; Waiyagan, Kriangkrai

2013-07-01

494

[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

2010-01-01

495

Influence of Squid Liver Powder on Accumulation of Cadmium in Serum, Kidney and Liver of Mice  

PubMed Central

In this study, the effect of squid liver powder intake on accumulation of cadmium in mice was investigated. Subjects were divided into 4 groups including the control group (CON), squid liver powder group with lipids not removed (SLP100), and squid liver powder groups with lipids removed (LFSLP50 and LFSLP100). Feed intake and food efficiency ratio of squid liver powder groups was significantly higher than the CON. As a result of investigating cadmium content in hair, serum, liver, and kidney during intake of squid liver powder, all groups showed increase in cadmium accumulation through consistent, long-term intake. Especially, cadmium content in liver and kidney of LFSLP100 was significantly higher than the content of SLP100 and CON. As a result of pathological observation on liver and kidney tissues according to squid liver powder diet, LFSLP100 showed most serious pathological symptoms. In case of kidney tissues, degeneration was significantly more severe in LFSLP100 compared to other groups. Such results suggest that cadmium concentration in human body can be increased by ingestion of whole squid including internal organs and that tissues can be damaged by increased cadmium concentration. More specific and systematic studies are deemed necessary. PMID:24471103

Kim, Byoung-Mok; Lee, Soo-Young; Jeong, In-Hak

2013-01-01

496

Instrumentation of a resonant gravitational radiation detector with a planar thin-film dc SQUID  

SciTech Connect

The instrumentation of a low-temperature three-mode gravitationa1 radiation antenna incorporating a low-noise dc SQUID provided by IBM is described. The feedback circuitry necessary to maintain the linearity and dynamic range of the SQUID was found to drive the resonant system due to high coupling between the input coil and the feedback coil of the SQUID. In order for this type of planar thin-film dc SQUID to be useful for gravitational radiation detectors and other applications requiring high Q input circuits, a solution to this feedback problem is needed. To this end, the nonlinear equations describing the dc SQUID with linear feedback are solved in terms of an isolated SQUID. The important feedback parameters for a high Q resonant system are found to be the slew rate of the electronics and the coupling constant ratio ..cap alpha../sup 2//sub i//sub f//..cap alpha../sup 2//sub f/, where ..cap alpha../sup 2//sub i//sub f/ is the energy coupling efficiency between the feedback coil and input coil and ..cap alpha../sup 2//sub f/ is the energy coupling efficiency between the feedback coil and the SQUID loop. Methods to reduce the effect of the feedback on the input circuit are also discussed.

Folkner, W.M.; Moody, M.V.; Richard, J.; Carroll, K.R.; Tesche, C.D.

1989-06-15

497

Low frequency magnetic resonance with a dc SQUID (Superconducting QUantum Interference Device)  

SciTech Connect

Conventional NMR and NQR spectrometers use transistor-based detectors, which are responsive only to voltage. This forces the experimenter to convert the sample magnetization to a voltage, a process that is less efficient at low frequencies when the Faraday induction effect is used. However, the SQUID directly measures the magnetization, so there is no frequency dependent sensitivity to the sample magnetization. Of course, many other devices also measure magnetic field directly, but none has the low frequency sensitivity of the SQUID. Chapter 2 presents the theory required to extend conventional magnetic resonance to z-axis magnetic resonance, a form most efficient for the SQUID. The operating principles of the SQUID, as well as the techniques used to convert the SQUID response into a useful output voltage, are outlined in Chapter 3. The SQUID spectrometer constructed for these experiments is described in Chapter 4. Also in this chapter are a discussion of the design considerations for a SQUID spectrometer, and indications of the overall performance of our instrument. Experimental results on NQR and low frequency NMR are found in Chapters 5 and 6, respectively. 96 refs., 38 figs., 5 tabs.

Connor, C.

1989-10-01

498

Make and Fly a Helicopter  

NSDL National Science Digital Library

Learners follow the template to build and fly a paper helicopter. They can attempt many experiments (shortening the blades, adding weight to the helicopter) and see how the flight of the helicopter is affected.

Museum of Science and Industry, Chicago

2012-01-01

499

Characterisation of Turkish fly ashes  

Microsoft Academic Search

The mineralogical, morphological, physical and chemical properties of seven different fly ashes from eastern, central and western lignite and bituminous coal fields in Turkey are compared in this study. The mineral matter in the fly ashes, determined by means of X-ray diffraction, is dominated mainly by anhydrite, lime, quartz and hematite + ferrite spinel. The three low-calcium ashes—Soma, Seyitomer and

Oktay Bayat

1998-01-01

500

Aminoglycoside-induced damage in the statocyst of the longfin inshore squid, Doryteuthis pealeii.  

PubMed

Squid are a significant component of the marine biomass and are a long-established model organism in experimental neurophysiology. The squid statocyst senses linear and angular acceleration and is the best candidate for mediating squid auditory responses, but its physiology and morphology are rarely studied. The statocyst contains mechano-sensitive hair cells that resemble hair cells in the vestibular and auditory systems of other animals. We examined whether squid statocyst hair cells are sensitive to aminoglycosides, a group of antibiotics that are ototoxic in fish, birds, and mammals. To assess aminoglycoside-induced damage, we used immunofluorescent methods to image the major cell types in the statocyst of longfin squid (Doryteuthis pealeii). Statocysts of live, anesthetized squid were injected with either a buffered saline solution or neomycin at concentrations ranging from 0.05 to 3.0 mmol l(-1). The statocyst hair cells of the macula statica princeps were examined 5 h post-treatment. Anti-acetylated tubulin staining showed no morphological differences between the hair cells of saline-injected and non-injected statocysts. The hair cell bundles of the macula statica princeps in aminoglycoside-injected statocysts were either missing or damaged, with the amount of damage being dose-dependent. The proportion of missing hair cells did not increase at the same rate as damaged cells, suggesting that neomycin treatment affects hair cells in a nonlethal manner. These experiments provide a reliable method for imaging squid hair cells. Further, aminoglycosides can be used to induce hair cell damage in a primary sensory area of the statocyst of squid. Such results support further studies on loss of hearing and balance in squid. PMID:25216502

Scharr, Alexandra L; Mooney, T Aran; Schweizer, Felix E; Ketten, Darlene R

2014-08-01