Sample records for neon flying squid

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

    E-print Network

    Chen, Yong

    Influence of El Nin~o/La Nin~a on the western winter­spring cohort of neon flying squid of neon flying squid (Ommastrephes bartramii) in the northwestern Pacific Ocean. ­ ICES Journal of Marine Science, 64: 00­00. Ommastrephes bartramii is an oceanic squid distributed widely in the North Pacific

  2. Variability of Suitable Habitat of Western Winter-Spring Cohort for Neon Flying Squid in the Northwest Pacific under Anomalous Environments

    PubMed Central

    Yu, Wei; Chen, Xinjun; Yi, Qian; Chen, Yong; Zhang, Yang

    2015-01-01

    We developed a habitat suitability index (HSI) model to evaluate the variability of suitable habitat for neon flying squid (Ommastrephes bartramii) under anomalous environments in the Northwest Pacific Ocean. Commercial fisheries data from the Chinese squid-jigging vessels on the traditional fishing ground bounded by 35°-45°N and 150°-175°E from July to November during 1998-2009 were used for analyses, as well as the environmental variables including sea surface temperature (SST), chlorophyll-a (Chl-a) concentration, sea surface height anomaly (SSHA) and sea surface salinity (SSS). Two empirical HSI models (arithmetic mean model, AMM; geometric mean model, GMM) were established according to the frequency distribution of fishing efforts. The AMM model was found to perform better than the GMM model. The AMM-based HSI model was further validated by the fishery and environmental data in 2010. The predicted HSI values in 1998 (high catch), 2008 (average catch) and 2009 (low catch) indicated that the squid habitat quality was strongly associated with the ENSO-induced variability in the oceanic conditions on the fishing ground. The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii. While the fishing ground in the El Niño year of 2009 experienced anomalous cool waters and unfavorable range of Chl-a concentration and SSHA, leading to relatively low-quality squid habitats. Our findings suggest that the La Niña event in 1998 tended to result in more favorable habitats for O. bartramii in the Northwest Pacific with the gravity centers of fishing efforts falling within the defined suitable habitat and yielding high squid catch; whereas the El Niño event in 2009 yielded less favorable habitat areas with the fishing effort distribution mismatching the suitable habitat and a dramatic decline of the catch of O. bartramii. This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change. PMID:25923519

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  4. First SQUIDs

    NASA Astrophysics Data System (ADS)

    Silver, Arnold

    2014-03-01

    The Superconducting QUantum Interference Device (SQUID) is the most sensitive magnetic flux sensor and the most widely applied superconductor electronic device, whose applications range from magnetocardiography to picovoltmeters, from digital logic to quantum computing, and from non-destructive testing to Gravity Probe B, a spaceborne test of Einstein's theory of gravity. In this presentation, I describe the initial experiments and device modeling at the Ford Scientific Laboratory that produced the early versions of the SQUID during the 1960's. That history originated in an anomalous observation during microwave ENDOR experiments and led to the first report of macroscopic quantum interference in superconductors in 1964 [Phys. Rev. Letters 12 (1964)]. The SQUID is based on London's electrodynamic theory of multiply-connected superconductors [Superfluids Wiley, New York (1950)], the magnetic flux quantum (h/2e=2.07E-15 Wb), and Josephson's theory of weakly-connected superconductors [Phys. Lett. 1 (1962)]. Physically, it incorporates Josephson tunnel junctions in a low inductance, superconducting ring. Two distinct types of SQUIDs were demonstrated: first the ``dc SQUID'' and then the ``rf SQUID.'' The former has two Josephson junctions and produces a dc frequency response; the latter has only one junction and responds only at rf and microwave frequencies. The first phase, conducted by Lambe, Jaklevic, Mercereau, and Silver, used type I thin film superconductors and Josephson tunnel junctions. The second phase, conducted by Silver and Zimmerman, used bulk niobium structures with ``cat whisker'' junction technology [Phys.Rev. 157 (1967)].

  5. Fly

    NSDL National Science Digital Library

    2014-07-11

    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.

  6. Holographic SQUID

    E-print Network

    Takeuchi, Shingo

    2013-01-01

    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.

  7. Portable neon purification system

    SciTech Connect

    Richardson, R.A.; Schmitt, R.L.

    1995-08-01

    This paper describes the principle design features of a portable neon purification system and the results of the system performance testing. Neon gas replaces air in the Ring Imaging Cherenkov detector without using vacuum, in experiment E781(SELEX) at Fermilab. The portable neon purification system purifies neon gas by, first purging air with CO{sub 2}, freezing the CO{sub 2}, then cryoadsorbing the remaining contaminants. The freezer removes carbon dioxide from a neon gas mixture down to a maximum concentration of 500 parts-per-million (ppm). The charcoal bed adsorber removes nitrogen from neon gas down to a maximum concentration of 100 ppm. The original RICH vessel was designed to hold vacuum but its photomultiplier tube plates were not.

  8. NEON Airborne Remote Sensing of Terrestrial Ecosystems

    NASA Astrophysics Data System (ADS)

    Kampe, T. U.; Leisso, N.; Krause, K.; Karpowicz, B. M.

    2012-12-01

    The National Ecological Observatory Network (NEON) is the continental-scale research platform that will collect information on ecosystems across the United States to advance our understanding and ability to forecast environmental change at the continental scale. One of NEON's observing systems, the Airborne Observation Platform (AOP), will fly an instrument suite consisting of a high-fidelity visible-to-shortwave infrared imaging spectrometer, a full waveform small footprint LiDAR, and a high-resolution digital camera on a low-altitude aircraft platform. NEON AOP is focused on acquiring data on several terrestrial Essential Climate Variables including bioclimate, biodiversity, biogeochemistry, and land use products. These variables are collected throughout a network of 60 sites across the Continental United States, Alaska, Hawaii and Puerto Rico via ground-based and airborne measurements. Airborne remote sensing plays a critical role by providing measurements at the scale of individual shrubs and larger plants over hundreds of square kilometers. The NEON AOP plays the role of bridging the spatial scales from that of individual organisms and stands to the scale of satellite-based remote sensing. NEON is building 3 airborne systems to facilitate the routine coverage of NEON sites and provide the capacity to respond to investigator requests for specific projects. The first NEON imaging spectrometer, a next-generation VSWIR instrument, was recently delivered to NEON by JPL. This instrument has been integrated with a small-footprint waveform LiDAR on the first NEON airborne platform (AOP-1). A series of AOP-1 test flights were conducted during the first year of NEON's construction phase. The goal of these flights was to test out instrument functionality and performance, exercise remote sensing collection protocols, and provide provisional data for algorithm and data product validation. These test flights focused the following questions: What is the optimal remote sensing data collection protocol to meet NEON science requirements? How do aircraft altitude, spatial sampling, spatial resolution, and LiDAR instrument configuration affect data retrievals? What are appropriate algorithms to derive ECVs from AOP data? What methodology should be followed to validate AOP remote sensing products and how should ground truth data be collected? Early test flights were focused on radiometric and geometric calibration as well as processing from raw data to Level-1 products. Subsequent flights were conducted focusing on collecting vegetation chemistry and structure measurements. These test flights that were conducted during 2012 have proved to be extremely valuable for verifying instrument functionality and performance, exercising remote sensing collection protocols, and providing data for algorithm and science product validation. Results from these early flights are presented, including the radiometric and geometric calibration of the AOP instruments. These 2012 flight campaigns are just the first of a series of test flights that will take place over the next several years as part of the NEON observatory construction. Lessons learned from these early campaigns will inform both airborne and ground data collection methodologies for future campaigns as well as guide the AOP sampling strategy before NEON enters full science operations.

  9. Ionization coefficients in helium, neon and helium-neon mixtures

    Microsoft Academic Search

    J Dutton; M H Hughes; B C Tan

    1969-01-01

    The spatial growth of pre-breakdown ionization currents at values of E\\/N (E is the electric field and N the gas number density) within the range from 2·24 × 10-16 to 11·2 × 10-16 v cm2 was measured for helium, for neon and for eight different helium-neon mixtures with fractional concentrations of neon ranging from 0·05 to 0·95. For neon and

  10. 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!

  11. Positron excitation of neon

    NASA Technical Reports Server (NTRS)

    Parcell, L. A.; Mceachran, R. P.; Stauffer, A. D.

    1990-01-01

    The differential and total cross section for the excitation of the 3s1P10 and 3p1P1 states of neon by positron impact were calculated using a distorted-wave approximation. The results agree well with experimental conclusions.

  12. Future Medicine From Squid

    NSDL National Science Digital Library

    Millot, Charmaine

    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.

  13. Chimeras in SQUID Metamaterials

    E-print Network

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

    2015-04-21

    Regular lattices comprising superconducting quantum interference devices (SQUIDs) form magnetic metamaterials exhibiting extraordinary properties, including tunability, dynamic multistability, and negative magnetic permeability. The SQUIDs in a metamaterial interact through nonlocal, magnetic dipole-dipole forces that makes it possible for counter-intuitive dynamic states referred to as chimera states to appear; the latter feature clusters of SQUIDs with synchronous dynamics which coexist with clusters exhibiting asynchronous behavior. The spontaneous appearance of chimera states is demonstrated numerically for one-dimensional 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 lifetimes. The synchronization and metastability levels of the chimera states are discussed in terms of appropriate measures. Given that both one- and two-dimensional SQUID metamaterials have been already fabricated and investigated in the laboratory, the presence of a chimera state could in principle be detected with presently available experimental setups.

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

    PubMed

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

    2014-01-01

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

  15. High pressure neon arc lamp

    DOEpatents

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  16. Optical fiber feedback SQUID magnetometer

    SciTech Connect

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

    1989-04-01

    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.

  17. Principles and applications of SQUIDs

    Microsoft Academic Search

    John Clarke

    1989-01-01

    An overview of the current status of dc and RF SQUIDs (superconducting quantum interference devices) is presented. Using Nb-based thin-film technology, a number of groups can now routinely fabricate dc SQUIDS with input circuits integrated on the same chip. At 4.2 K, the dc SQUID, which operates with a constant bias current, can detect signals with an equivalent energy per

  18. SQUID With Integral Flux Concentrator

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.; Sisk, Robert C.

    1989-01-01

    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.

  19. SQUID technology for geophysical exploration

    NASA Astrophysics Data System (ADS)

    Meyer, Hans-Georg; Stolz, R.; Chwala, A.; Schulz, M.

    2005-03-01

    We report on successful tests of planar LTS SQUID gradiometers on airborne platforms such as helicopter and aircraft. The system works stable and allows profile work without any constraints. In mobile applications the gradient resolution at low frequencies is dominated by motion noise, since the parasitic areas of the SQUID gradiometer lead to strong disturbances if the gradiometer is tilted in the homogenous Earth's magnetic field. The balance can be improved further by software using data of a SQUID magnetometer triple.

  20. Japan's Squid Fishing Industry WILLIAM G. COURT

    E-print Network

    Japan's Squid Fishing Industry WILLIAM G. COURT .. Introduction Dried-squid (surume) has been an item of commerce, ceremony, and diet in Japan for hundreds of years, and squid is caught of the fishery. In 1952 squid landings reached 646,730 tons and, at 15 percent of the total, became Japan's most

  1. In Search of the Giant Squid

    NSDL National Science Digital Library

    The truth about this mysterious giant based on the exhibit by the National Museum of Natural History. A complete guide to the giant squid, including the different species of squid, how squid move, eat, and defend themselves, as well as photographs from the exhibit. Features also include information on the vessels and equipment used to investigate the giant squid, the locations where the giant squid were searched for, and a daily journal of the expedition.

  2. SQUIDs: microscopes and nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Mück, Michael

    2005-03-01

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

  3. Neon isotopes in submarine basalts

    Microsoft Academic Search

    Philippe Sarda; Thomas Staudacher; Claude J. Allègre

    1988-01-01

    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

  4. Biomagnetic susceptometer with SQUID instrumentation

    SciTech Connect

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

    1991-03-01

    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.

  5. Principles and applications of SQUIDs

    NASA Astrophysics Data System (ADS)

    Clarke, John

    1989-08-01

    An overview of the current status of dc and RF SQUIDs (superconducting quantum interference devices) is presented. Using Nb-based thin-film technology, a number of groups can now routinely fabricate dc SQUIDS with input circuits integrated on the same chip. At 4.2 K, the dc SQUID, which operates with a constant bias current, can detect signals with an equivalent energy per unit bandwidth of a few hundred h/2pi RF SQUIDs, which operate with an RF flux bias, are usually machined from bulk Nb, and have a typical energy sensitivity per unit bandwidth of 10 to the 5th to 10 to the 6th h/2pi. Both types of SQUID can be used in a wide variety of applications, including magnetometers, gradiometers, susceptometers, voltmeters, RF amplifiers, gravity-wave antennas, and gravity gradiometers. Both dc and RF SQUIDs have been fabricated from high-temperature superconductors and operated at temperatures of up to 77 K. These devices exhibit high levels of 1/f noise, which generally arises from the motion of trapped magnetic flux.

  6. Chromophores in photoproteins of a glowing squid and mollusk.

    PubMed

    Kuse, Masaki

    2014-01-01

    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

  7. SQUID holder with high magnetic shielding

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  8. 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

  9. Tracking Electromagnetic Energy With SQUIDs

    NASA Technical Reports Server (NTRS)

    2005-01-01

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

  10. Flying wings / flying fuselages

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  11. A holographic model of SQUID

    E-print Network

    Cai, Rong-Gen; Zhang, Hai-Qing

    2013-01-01

    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.

  12. A holographic model of SQUID

    E-print Network

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

    2013-12-16

    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.

  13. Rearing of Cuttlefishes and Squids

    Microsoft Academic Search

    Sang Choe; YASUO OHSHIMA

    1963-01-01

    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:

  14. Cold SQUIDs and hot samples

    SciTech Connect

    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

    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.

  15. Biomagnetic Measurements Using SQUID Instrumentation

    NASA Astrophysics Data System (ADS)

    Rassi, D.; Zhuravlev, Y.

    2000-09-01

    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.

  16. Bright Squid Found In Hawaii

    NSDL National Science Digital Library

    Randolph E. Schmid

    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.

  17. 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

  18. Night flying

    NASA Technical Reports Server (NTRS)

    Warner, Edward P

    1922-01-01

    Dr. Warner examines the utility and economy of flying at night when flying passengers. Some of the points discussed include lighted landing fields, the possibility of using airships, and the cost of landing fields.

  19. Helium and Neon in Comets

    NASA Technical Reports Server (NTRS)

    Jewitt, David

    1996-01-01

    Two comets were observed with EUVE in late 1994. Both comet Mueller and comet Borrelly are short-period comets having well established orbital elements and accurate ephemerides. Spectra of 40 ksec were taken of each. No evidence for emission lines from either Helium or Neon was detected. We calculated limits on the production rates of these atoms (relative to solar) assuming a standard isotropic outflow model, with a gas streaming speed of 1 km/s. The 3-sigma (99.7% confidence) limits (1/100,000 for He, 0.8 for Ne) are based on a conservative estimate of the noise in the EUVE spectra. They are also weakly dependent on the precise pointing and tracking of the EUVE field of view relative to the comet during the integrations. These limits are consistent with ice formation temperatures T greater than or equal to 30 K, as judged from the gas trapping experiments of Bar-Nun. For comparison, the solar abundances of these elements are He/O = 110, Ne/O = 1/16. Neither limit was as constraining as we had initially hoped, mainly because comets Mueller and Borrelly were intrinsically less active than anticipated.

  20. Microwave-free manipulation of a SQUID qubit

    E-print Network

    Fominov, Yakov

    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

  1. Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

    PubMed Central

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

    2015-01-01

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

  2. Mining Helium programs with Neon Jurriaan Hage

    E-print Network

    Utrecht, Universiteit

    Mining Helium programs with Neon Jurriaan Hage Peter van Keeken Department of Information in a first-year functional programming course using the Helium compiler. The mining of such a collection to resolve a type error. 1 #12;1 Introduction and motivation When the Helium compiler for learning Haskell

  3. A MINIATURE SQUID MAGNETOMETER FOR BIOMAGNETIC MEASUREMENTS WITH IMPROVED SELECTIVITY

    E-print Network

    Paris-Sud XI, Université de

    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

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

    E-print Network

    SCHOOL STRUCTURE OF THE SQUID LOLIGO OPALESCENS ANN C. HURLEY! ABSTRACT The squid Loligo opalescens that the main sensory modality regulating schooling is vision. Squid on opposite sides ofa clear rigid Plexiglas barrier readily schooled. The structure ofschools ofsix squid depended on size of individuals

  5. A Taste of Crispy Squid Syam Gadde, Jeff Chase

    E-print Network

    Rabinovich, Michael "Misha"

    A Taste of Crispy Squid Syam Gadde, Jeff Chase Dept. of Computer Science Duke University Durham NC cache structures in Crispy Squid, an extension to the Squid Internet Object Cache. We are evaluating] and the public­domain Squid caches [20]. Hierarchical Web caches are built as a collective of independent proxy

  6. 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

  7. Experimental Jigging for Squid off the Northeast United States

    E-print Network

    Experimental Jigging for Squid off the Northeast United States Figure 1.- Polish research vessel attraction jigging is a fishing technique specifically developed for catching squid. Jigging for squid is one of the most important methods used in coastal squid fisheries in Japan. In Japan about 95 percent

  8. 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

  9. A Mechanical Device to Sort Market Squid, Loligo opalescens

    E-print Network

    A Mechanical Device to Sort Market Squid, Loligo opalescens Introduction Squid is an excellent. Indeed, high quality squid is regarded as a gourmet food in many countries, particularly in the Orient and Mediterranean Europe. However, U.S. consumers are hesitant to buy whole squid because of its ap pearance

  10. A 200 # twostage dc SQUID amplifier for resonant detectors

    E-print Network

    A 200 # two­stage dc SQUID amplifier for resonant detectors . In a resonant GW detector/2 ) and the Bandwidth (µ[S vv /S ii ] 1/2 ) . The two­stage dc SQUID amplifier, based on commercial (Quantum Design . A feedback damping network suitable for both the resonator­SQUID system and the GW detector­SQUID system

  11. Black Flies

    NSDL National Science Digital Library

    0000-00-00

    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.

  12. The House Fly and Other Filth Flies

    NSDL National Science Digital Library

    0000-00-00

    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.

  13. Aperture effects in squid jet propulsion.

    PubMed

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

    2014-05-01

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

  14. Drain Flies (Moth Flies or Filter Flies)

    E-print Network

    Sansone, Chris; Minzenmayer, Rick

    2003-07-21

    sinks and tubs. This fly belongs to the family Psychodidae. Biology and Habits Adult drain flies are small ( 1 /6 to 1 /5 inch long), dark, and densely covered with hairs. They hold their large wings roof-like over the body when at rest, giving them a... the larval food source. Clean pipes and traps with a stiff, long- handled brush. After a thorough scrubbing, flush the lines with boiling water to remove any material left behind. There is no benefit to treat- ing drains with chlorine bleach or ammonia. 2...

  15. ASA's Chandra Neon Discovery Solves Solar Paradox

    NASA Astrophysics Data System (ADS)

    2005-07-01

    NASA's Chandra X-ray Observatory survey of nearby sun-like stars suggests there is nearly three times more neon in the sun and local universe than previously believed. If true, this would solve a critical problem with understanding how the sun works. "We use the sun to test how well we understand stars and, to some extent, the rest of the universe," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "But in order to understand the sun, we need to know exactly what it is made of," he added. It is not well known how much neon the sun contains. This is critical information for creating theoretical models of the sun. Neon atoms, along with carbon, oxygen and nitrogen, play an important role in how quickly energy flows from nuclear reactions in the sun's core to its edge, where it then radiates into space. Chandra X-ray Spectrum of II Pegasi Chandra X-ray Spectrum of II Pegasi The rate of this energy flow determines the location and size of a crucial stellar region called the convection zone. The zone extends from near the sun's surface inward approximately 125,000 miles. The zone is where the gas undergoes a rolling, convective motion much like the unstable air in a thunderstorm. "This turbulent gas has an extremely important job, because nearly all of the energy emitted at the surface of the sun is transported there by convection," Drake said. The accepted amount of neon in the sun has led to a paradox. The predicted location and size of the solar convection zone disagree with those deduced from solar oscillations. Solar oscillations is a technique astronomers previously relied on to probe the sun's interior. Several scientists have noted the problem could be fixed if the abundance of neon is in fact about three times larger than currently accepted. Attempts to measure the precise amount of neon in the Sun have been frustrated by a quirk of nature; neon atoms in the Sun give off no signatures in visible light. However, in a gas heated to millions of degrees, neon shines brightly in X-rays. Stars like the sun are covered in this super-heated gas that is betrayed by the white corona around them during solar eclipses. However, observations of the sun's corona are very difficult to analyze. Labeled Illustration of Convection in Sun-like Star Labeled Illustration of Convection in Sun-like Star To probe the neon content, Drake and his colleague Paola Testa of the Massachusetts Institute of Technology in Cambridge, Mass., observed 21 sun-like stars within a distance of 400 light years from Earth. These local stars and the sun should contain about the same amount of neon when compared to oxygen. However, these close stellar kin were found to contain on average almost three times more neon than is believed for the sun. "Either the sun is a freak in its stellar neighborhood, or it contains a lot more neon than we think," Testa said. These Chandra results reassured astronomers the detailed physical theory behind the solar model is secure. Scientists use the model of the sun as a basis for understanding the structure and evolution of other stars, as well as many other areas of astrophysics. "If the higher neon abundance measured by Drake and Testa is right, then it is a simultaneous triumph for Chandra and for the theory of how stars shine," said John Bahcall of the Institute for Advanced Study, Princeton, N.J. Bahcall is an expert in the field who was not involved in the Chandra study. Drake is lead author of the study published in this week's issue of the journal Nature. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

  16. Diffusion of neon in white dwarf stars.

    PubMed

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

    2010-12-01

    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

  17. Squid based beam current meter

    SciTech Connect

    Kuchnir, M.

    1983-11-25

    A SQUID based beam current meter has the capability of measuring the current of a beam with as little as 30 x 155 antiprotons (with a signal to noise ratio of 2). If low noise dc current is used to cancel most of the beam or an up-down counter is used to count auto-resets this sensitivity will be available at any time in the acumulation process. This current meter will therefore be a unique diagnostic tool for optimizing the performance of several Tev I components. Besides requiring liquid helium it seems that its only drawback is not to follow with the above sensitivity a sudden beam change larger than 16 ..mu..A, something that could be done using a second one in a less sensitive configuration.

  18. Density functional calculations on neon satellites

    Microsoft Academic Search

    Amlan K. Roy; B. M. Deb

    1998-01-01

    A simple density-functional formalism, within the single-determinantal approach, has been employed to calculate the non-relativistic energies and densities for various satellites in the neon atom. 2s–ns and 2p–np (n=3–6) satellites accompanying 1s ionization and several Ne+ excited states, originating from the simultaneous excitation of 2s and 2p valence electrons, are calculated. A Kohn–Sham-type differential equation is solved numerically by employing

  19. Fly School

    NSDL National Science Digital Library

    2009-04-14

    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.

  20. Electron excitation coefficients for 2p state of neon

    Microsoft Academic Search

    J. V. Bozin; G. N. Malovic; B. M. Jelenkovic; Z. Lj. Petrovic

    1997-01-01

    Electron excitation rate coefficients for the 2p state of neon atom, (from 2p1-2p10 in Paschen notation) have been measured using an electron drift-tube technique. The absolute excitation coefficients were obtained from the optical signal at the anode in Townsend neon discharges, after correction for the detector quantum efficiency. The data were obtained for the electric field to neon number density

  1. Electron excitation coefficients for 2p state of neon

    Microsoft Academic Search

    G. N. Malovi?; J. V. Božin; B. M. Jelenkovi?; Z. Lj. Petrovi?

    1997-01-01

    Electron excitation rate coefficients for the 2p state of neon atom, (from 2p1–2p10 in Paschen notation) have been measured using an electron drift-tube technique. The absolute excitation coefficients were obtained from the optical signal at the anode in Townsend neon discharges, after correction for the detector quantum efficiency. The data were obtained for the electric field to neon number density

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

    NASA Technical Reports Server (NTRS)

    Pepper, S. V.

    1986-01-01

    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.

  3. Response of thin-film SQUIDs to applied fields and vortex fields: Linear SQUIDs

    NASA Astrophysics Data System (ADS)

    Clem, John R.; Brandt, Ernst Helmut

    2005-11-01

    In this paper we analyze the properties of a dc superconducting quantum interference device (SQUID) when the London penetration depth ? is larger than the superconducting film thickness d . We present equations that govern the static behavior for arbitrary values of ?= ?2 /d relative to the linear dimensions of the SQUID. The SQUID’s critical current Ic depends upon the effective flux ? , the magnetic flux through a contour surrounding the central hole plus a term proportional to the line integral of the current density around this contour. While it is well known that the SQUID inductance depends upon ? , we show here that the focusing of magnetic flux from applied fields and vortex-generated fields into the central hole of the SQUID also depends upon ? . We apply this formalism to the simplest case of a linear SQUID of width 2w , consisting of a coplanar pair of long superconducting strips of separation 2a , connected by two small Josephson junctions to a superconducting current-input lead at one end and by a superconducting lead at the other end. The central region of this SQUID shares many properties with a superconducting coplanar stripline. We calculate magnetic-field and current-density profiles, the inductance (including both geometric and kinetic inductances), magnetic moments, and the effective area as a function of ?/w and a/w .

  4. Observation of Qubit State with a dc-SQUID and Dissipation Effect in the SQUID

    Microsoft Academic Search

    Hideaki Takayanagi; Hirotaka Tanaka; Shiro Saito; Hayato Nakano

    2002-01-01

    Two states of a flux qubit with three Josephson junctions were shown in a single measurement with a dc-SQUID. The qubit is an aluminum superconductor loop surrounded by a dc-SQUID for readout. It has two states, which have persistent currents flowing in opposite directions. The readout data for three samples with different junction sizes suggest that the probability distribution for

  5. Observation of Qubit State with a dc-SQUID and Dissipation Effect in the SQUID

    Microsoft Academic Search

    Hideaki Takayanagi; Hirotaka Tanaka; Shiro Saito; Hayato Nakano

    2003-01-01

    Two states of a flux qubit with three Josephson junctions were shown in a single measurement with a dc-SQUID. The qubit is an aluminum superconductor loop surrounded by a dc-SQUID for readout. It has two states, which have persistent currents flowing in opposite directions. The readout data for three samples with different junction sizes suggest that the probability distribution for

  6. ICP and the Squid Web Cache \\Lambda Duane Wessels

    E-print Network

    California at San Diego, University of

    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

  7. Boundary Field Theory Approach to the Renormalization of SQUID Devices

    E-print Network

    Domenico Giuliano; Pasquale Sodano

    2006-12-14

    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.

  8. Optogalvanic spectra of neon and argon in glow discharge lamps.

    PubMed

    Nestor, J R

    1982-11-15

    Optogalvanic spectra of atomic neon and argon have been obtained by irradiating miniature glow discharge lamps with a pulsed, tunable dye laser. The method is shown to be useful for wavelength calibration of tunable lasers, and the resonant lines are cataloged. Two-photon absorption lines in neon are observed when the laser is focused into a small region of the discharge. PMID:20401023

  9. Microstrip SQUID amplifiers for quantum information science

    NASA Astrophysics Data System (ADS)

    Defeo, M. P.; Plourde, B. L. T.

    2012-02-01

    Recent progress in SQUID amplifiers suggests that these devices might approach quantum-limited sensitivity in the microwave range, thus making them a viable option for measurement of superconducting quantum systems. In the microstrip SQUID amplifier configuration, gains of around 20dB are possible at frequencies of several hundred MHz, and the gain is limited by the maximum voltage modulation available from the SQUID. One route for increasing the voltage modulation involves using larger resistive shunts, however maintaining non-hysteretic device operation requires smaller junction capacitances than is possible with conventional photolithographically patterned junctions. Operating at higher frequencies requires a shorter input coil which reduces mutual inductance between the coil and washer and therefore gain. We have fabricated microstrip SQUID amplifiers using submicron Al-AlOx-Al junctions and large shunts. The input coil and SQUID washer are optimized for producing high gain at frequencies in the gigahertz range. Recent measurements of gain and noise temperature will be discussed as well as demonstrations of these devices as a first stage of amplification for a superconducting system

  10. The effects of radio frequency radiation on the dc SQUID

    SciTech Connect

    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

    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.

  11. 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

  12. Experimental Pair Trawling for Squid in New England

    E-print Network

    Experimental Pair Trawling for Squid in New England ALAN J. BLOTT Introduction In pair trawling was to test the feasibility of harvesting winter or longfin squid, Loligo pealei, in inshore waters with a bottom pair trawl. Procedure Two pair trawlers which had pre- viously been used in the squid fishery

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

    E-print Network

    533 Abstract--Three experiments were performed in an estuarine squid- trawl fishery in New South to reduce nontargeted catches of fish, while maintaining catches of the targeted broad squid (Photololigo etheridgei) and bottle squid (Loliolus noctiluca). Compared to conventional codends made with 41-mm diamond

  14. J.Z. AND THE DISCOVERY OF SQUID GIANT NERVE

    E-print Network

    Fullard, James H.

    179 J.Z. AND THE DISCOVERY OF SQUID GIANT NERVE FIBRES Richard Keynes writes about J. Z. Young's 1938 ground-breaking publication on the function of squid giant nerve fibres. A PDF file of Young to further studies at the Plymouth Marine Laboratory of some structures in the mantles of squid that he

  15. 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

  16. Low Field dc SQUID NMR on Room Temperature Samples

    E-print Network

    Sheldon, Nathan D.

    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

  17. Information Panel The Embryonic Development of the Hawaiian Bobtail Squid

    E-print Network

    McFall-Ngai, Margaret

    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

  18. Development of a Squid Skinning and Eviscerating System

    E-print Network

    Development of a Squid Skinning and Eviscerating System R. PAUL SINGH and DANIEL E. BROWN Introduction Despite its excellent food value, a North American market for squid is vir- tually non-existent. The appearance of whole squid is unappetizing to many in the market place despite its relatively low retail price

  19. Abstract--The California market squid (Loligo opalescens) has been

    E-print Network

    46 Abstract--The California market squid (Loligo opalescens) has been harvested since the 1860s 1983. The California Department of Fish and Game (CDFG) collects information on landings of squid), and their respective anomalies. We found that the squid fishery in Monterey Bay expends twice the effort

  20. "Saki-ika": Dried Squid Processing Equipment and Markets

    E-print Network

    "Saki-ika": Dried Squid Processing Equipment and Markets DANIEL J SHEEHY and SUSAN F. VIK · Introduction Squid has been widely recognized as an underutilized food fishery in the United States. Only 18. In northwest Atlantic waters, most squid landings are incidental to trawl effort for finfishes (Lux et a

  1. INTRODUCTION Squid employ a complex locomotive approach involving two

    E-print Network

    Stewart, William J.

    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

  2. Paleomagnetic analysis using SQUID microscopy Benjamin P. Weiss,1

    E-print Network

    Weiss, Benjamin P.

    Paleomagnetic analysis using SQUID microscopy Benjamin P. Weiss,1 Eduardo A. Lima,1,2 Luis E. Fong; published 19 September 2007. [1] Superconducting quantum interference device (SQUID) microscopes are a new sensitivity. Unlike standard rock magnetometers, SQUID microscopes map magnetic fields rather than measuring

  3. Squid Pax-6 and eye development.

    PubMed

    Tomarev, S I; Callaerts, P; Kos, L; Zinovieva, R; Halder, G; Gehring, W; Piatigorsky, J

    1997-03-18

    Pax-6 in vertebrates and its homolog eyeless in Drosophila are known to be essential for eye development. Here we investigate the role of Pax-6 in eye development in another major systematic group, molluscs. We demonstrate that alternatively spliced RNAs derived from a single Pax-6 gene in the squid (Loligo opalescens) are expressed in the embryonic eye, olfactory organ, brain, and arms. Despite significant sequence differences between squid Pax-6 and Drosophila eyeless in the region outside the paired- and homeodomains, squid Pax-6 is able to induce the formation of ectopic eyes in Drosophila. Our results support the idea that Pax-6 related genes are necessary for eye and olfactory system formation throughout the animal kingdom. PMID:9122210

  4. Diffusion of Neon in White Dwarf Stars

    E-print Network

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

    2010-11-29

    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.

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

    Microsoft Academic Search

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

    2003-01-01

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

  6. Biological applications of the SQUID microscope

    NASA Astrophysics Data System (ADS)

    Chemla, Yann Robert

    The recently developed "microscope" based on a high-T c dc SQUID (Superconducting QUantum Interference Device) is used to detect the magnetic fields produced by biological samples maintained at room temperature and atmospheric pressure. The microscope consists of a SQUID placed on the end of a sapphire "cold finger" thermally anchored to a liquid nitrogen reservoir inside a vacuum enclosure. A 3-mu m thick silicon nitride (SiN) membrane, located above the SQUID, acts as a vacuum window. Room temperature samples are placed on top of the window and can be brought within 15mum of the SQUID. In Part I, the SQUID microscope is used to investigate magnetotactic bacteria, microorganisms which possess a permanent dipole moment. The magnetic field produced by the motion of the bacteria in growth medium is detected by the SQUID in the microscope. Measurements are performed on both motile and nonmotile bacteria. In the nonmotile case, we obtain the power spectrum of the magnetic flux noise produced by the rotational Brownian motion of the ensemble of bacteria. Furthermore, we measure the time-dependent flux produced by the ensemble in response to an applied uniform magnetic field. In the motile case, we obtain the magnetic flux power spectra produced by the swimming bacteria. Combined, these measurements determine the average rotational drag coefficient, magnetic moment, and the frequency and amplitude of the vibrational and rotational modes of the bacteria in a unified set of measurements. In addition, the microscope can easily resolve the motion of a single bacterium. This technique can be extended to any biological substance to which a suitable magnetic label can be attached. In Part II, a technique is described for the specific, sensitive, quantitative, and rapid detection of biological targets using superparamagnetic nanoparticle labels. In this technique, a mylar film to which the targets have been bound is placed on the microscope, typically 40mum from the SQUID. A suspension of magnetic nanoparticles carrying antibodies directed against the target is added to the mixture in the well, and one-second pulses of magnetic field are applied parallel to the SQUID. In the presence of this aligning field the nanoparticles develop a net magnetization, which relaxes when the field is turned off. Unbound nanoparticles relax rapidly by Brownian rotation and contribute no measurable signal. Nanoparticles that are bound to the target on the film are immobilized and undergo Neel relaxation, producing a slowly decaying magnetic flux which is detected by the SQUID. The ability to distinguish between bound and unbound labels allows one to run homogeneous assays, which do not require separation and removal of unbound magnetic particles. The technique has been demonstrated with a model system of liposomes carrying the FLAG epitope. The SQUID microscope requires no more than (5 +/- 2) x 104 magnetic nanoparticles to register a reproducible signal. Improvements to the SQUID microscope designed to increase its sensitivity are discussed. An experiment is proposed in which the microscope is used as a single molecule probe, detecting a single magnetic label attached to a biological macromolecule like DNA.

  7. OpenSQUID: a flexible open-source software framework for the control of SQUID electronics

    E-print Network

    Jaeckel, Felix T; Boyd, S T P

    2012-01-01

    Commercially available computer-controlled SQUID electronics are usually delivered with software providing a basic user interface for adjustment of SQUID tuning parameters, such as bias current, flux offset, and feedback loop settings. However, in a research context it would often be useful to be able to modify this code and/or to have full control over all these parameters from researcher-written software. In the case of the STAR Cryoelectronics PCI/PFL family of SQUID control electronics, the supplied software contains modules for automatic tuning and noise characterization, but does not provide an interface for user code. On the other hand, the Magnicon SQUIDViewer software package includes a public application programmer's interface (API), but lacks auto-tuning and noise characterization features. To overcome these limitations, we are developing an open-source framework for controlling SQUID electronics which should provide maximal interoperability with user software, a unified user interface for electron...

  8. Drag force and jet propulsion investigation of a swimming squid

    NASA Astrophysics Data System (ADS)

    Tabatabaei, Mahdi; Bahad?r Olcay, Ali; Gokçen, Gökhan; Heperkan, Hasan A.

    2015-05-01

    In this study, CAD model of a squid was obtained by taking computer tomography images of a real squid. The model later placed into a computational domain to calculate drag force and performance of jet propulsion. The drag study was performed on the CAD model so that drag force subjected to real squid was revealed at squid's different swimming speeds and comparison has been made with other underwater creatures (e.g., a dolphin, sea lion and penguin). The drag coefficient (referenced to total wetted surface area) of squid is 0.0042 at Reynolds number 1.6x106 that is a %4.5 difference from Gentoo penguin. Besides, jet flow of squid was simulated to observe the flow region generated in the 2D domain utilizing dynamic mesh method to mimic the movement of squid's mantle cavity.

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

    SciTech Connect

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

    1991-03-01

    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.

  10. Bioelectronics: A positive future for squid proteins

    NASA Astrophysics Data System (ADS)

    Rolandi, Marco

    2014-07-01

    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.

  11. Cadmium Block of Squid Calcium Currents

    Microsoft Academic Search

    ROBERT H. CHOW

    1991-01-01

    The mechanism of Cd 2+ block of Ca *+ currents (\\/ca) was explored in squid neurons using whole-cell patch damp. Control currents activated sigmoidally, more rapidly at more positive potentials, and did not inactivate significantly. External Cd =+ up to 250 CM reduced lc~ reversibly. For small depolarizations, the current for a step of 10 ms increased to a maintained

  12. Multichannel SQUID systems for brain research

    SciTech Connect

    Ahonen, A.I.; Hamalainen, M.S.; Kajola, M.J.; Knuutila, J.E.F.; Lounasmaa, O.V.; Simola, J.T.; Vilkman, V.A. (Helsinki Univ. of Technology, Espoo (Finland). Low Temperature Lab.); Tesche, C.D. (International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center)

    1991-03-01

    This paper reviews basis principles of magnetoencephalography (MEG) and neuromagnetic instrumentation. The authors' 24-channel system, based on planar gradiometer coils and dc-SQUIDs, is then described. Finally, recent MEG-experiments on human somatotopy and focal epilepsy, carried out in the authors' laboratory, are presented.

  13. Triple Photoionization of Neon Near Threshold

    NASA Astrophysics Data System (ADS)

    Bluett, J. B.; Whitfield, S. B.; Luki?, D.; Sellin, I. A.; Azuma, Y.; Wehlitz, R.

    2002-05-01

    The threshold behavior of the triple ionization cross-section of neon was investigated using monochromatized synchotron radiation and ion time-of-flight spectroscopy. The absolute cross-section is found to follow the Wannier power law(G.H. Wannier, Phys. Rev. 90), 817 (1953). in E with an exponent of 2.27 0.25 that has a range of validity of 5.5 eV. This result is consistent with the exponent of 2.162 predicted by theory and is also consistent with the findings of Samson and Angel(J.A.R. Samson and G.C. Angel, Phys. Lett. 61), 1584 (1988).. Further tests were performed over a range of 25 eV to determine the possibility of resonances and a secondary power law for energies above 5.5 eV.

  14. Microscopic relaxation in supercritical and liquid neon

    NASA Astrophysics Data System (ADS)

    Cunsolo, A.; Pratesi, G.; Verbeni, R.; Colognesi, D.; Masciovecchio, C.; Monaco, G.; Ruocco, G.; Sette, F.

    2001-02-01

    The high frequency behavior of the dynamic structure factor, S(Q,?), of liquid and supercritical neon is investigated by inelastic x-ray scattering at different temperatures and pressure. The spectral evolution is described in terms of a single-relaxation-time viscoelastic model. The occurrence of a positive dispersion in the sound velocity is clearly visible in both investigated thermodynamic phases. The anomalies in the dispersive behavior deeply reduce at the higher temperatures, probably, as a consequence of important changes in the first shell interactions. More generally, the atomic dynamics is dominated by a relaxation process whose time scale is in the range of fast microscopic degrees of freedom (?10-13 s), and whose strength and typical time scale stay constant over all the explored liquid and supercritical regions.

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

    E-print Network

    Boyer, Edmond

    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

  16. Helium and Neon in "Blank" Stardust Aerogel Samples

    NASA Astrophysics Data System (ADS)

    Palma, R. L.; Pepin, R. O.; Westphal, A.; Schlutter, D.; Gainsforth, Z.

    2012-03-01

    Helium and neon concentrations and compositions were measured in 49 samples of "blank" aerogel from Stardust cell C2044. Five samples show interesting compositions that if related to the Track 41 impactor indicate a complicated parent particle.

  17. Moderately shielded high-Tc SQUID system for rat MCG

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    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.

  18. Viscosity and Thermal Conductivity of Binary Gas Mixtures: Argon-Neon, Argon-Helium, and Neon-Helium

    Microsoft Academic Search

    E. Thornton; W. A. D. Baker

    1962-01-01

    The coefficients of viscosity and thermal conductivity of the binary gas mixtures argon-neon, argon-helium and neon-helium, have been determined over the full range of composition of each mixture at a pressure of 70 cm of mercury and at a temperature in the range 18.0 to 18.3 °C. The experimental values are compared with theoretical values based on the Lennard-Jones (6-12)

  19. SQUID-based multichannel system for Magnetoencephalography

    E-print Network

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

    2013-01-01

    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

  20. A modular low noise 7-channel SQUID-magnetometer

    Microsoft Academic Search

    O. Dossel; B. David; M. Fuchs; W. H. Kullmann; K. M. Ludeke

    1991-01-01

    A modular low-noise seven-channel SQUID-magnetometer for biomagnetic measurements was developed. The DC-SQUIDs are prepared by thin film technology based on the materials NbN-MgO-NbN, and show a flux noise below 10 ??0\\/?Hz. The signal is picked up with first-order wire-wound gradiometers of 2-cm diameter and coupled to the SQUIDs by integrated coupling coils. Individual channels can be replaced from the system,

  1. MFR PAPER 1023 While the world squid etch octupl d

    E-print Network

    MFR PAPER 1023 While the world squid etch octupl d between 1938 and 1968, th r"SOlJrC potent/aIls stili enormous Northwest Atlantic Squids WARREN F. RATHJEN In 19 the \\\\{ fld \\..,Idl II qUId ,1Il1l" FAO f'isheries ircular o. 1~9) re- \\Ie\\\\ of v. orld squid ..Inu ,)CIl'PU" potentials. \\ oss andlcateu

  2. The Renormalization Effects in the Microstrip-SQUID Amplifier

    E-print Network

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

    2011-10-25

    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.

  3. Digital filter design approach for SQUID gradiometers

    SciTech Connect

    Bruno, A.C.; Ribeiro, P.C.

    1988-04-15

    A review of the traditional method for designing gradiometers is made. A nonrecursive digital filter model for the gradiometer is presented, giving a new set of parameters for the gradiometer identification. Some designs are analyzed using the proposed set. As an example, a true differentiator is designed to be used as the SQUID input coil. It is shown that the differentiator has the same noise rejection as the conventional gradiometer but provides more signal sensitivity.

  4. Investigation of noise sources in SQUID electronics

    Microsoft Academic Search

    T. R. Clem; M. J. Goldstein; J. W. Purpura; L. H. Allen; J. H. Claassen

    1989-01-01

    The performance of SQUID (superconducting quantum interference device)-based electronics may be degraded from that found in laboratory operation. Investigations on superconducting tubes, wires, and sheets have been conducted to identify contributions to such noise. Results have been obtained for bulk and thin-film samples utilizing both the conventional low-temperature materials and the new high-temperature oxide materials. Experiments have been conducted to

  5. Odorant Responsiveness of Squid Olfactory Receptor Neurons

    PubMed Central

    Mobley, Arie Sitthichai; Michel, William C.; Lucero, Mary T.

    2008-01-01

    In the olfactory organ of the squid, Lolliguncula brevis there are five morphological types of olfactory receptor neurons (ORNs). Previous work to characterize odor sensitivity of squid ORNs was performed on only two of the five types in dissociated primary cell cultures. Here we sought to establish the odorant responsiveness of all five types. We exposed live squid or intact olfactory organs to excitatory odors plus the activity marker, agmatine (AGB), an arginine derivative that enters cells through non-selective cation channels. An antibody against AGB was used to identify odorant-activated neurons. We were able to determine the ORN types of AGB-labeled cells based on their location in the epithelium, morphology and immunolabeling by a set of metabolites: arginine, aspartate, glutamate, glycine and glutathione. Of 389 neurons identified from metabolite-labeled tissue, 3% were type 1, 32% type 2, 33% type 3, 15% type 4 and 17% type 5. Each ORN type had different odorant specificity with type 3 cells showing the highest percentages of odorant-stimulated AGB labeling. Type 1 cells were rare and none of the identified type 1 cells responded to the tested odorants, which included glutamate, alanine and AGB. Glutamate is a behaviorally attractive odorant and elicited AGB labeling in types 2 and 3. Glutamate-activated AGB labeling was significantly reduced in the presence of the adenylate cyclase inhibitor, SQ22536 (80 ?M). These data suggest that the five ORN types differ in their relative abundance and odor responsiveness and that the adenylate cyclase pathway is involved in squid olfactory transduction. PMID:18484602

  6. Directly coupled YBCO dc SQUID magnetometers

    NASA Astrophysics Data System (ADS)

    Petersen, P. R. E.; Shen, Y. Q.; Sager, M. P.; Holst, T.; Larsen, B. H.; Bindslev Hansen, J.

    1999-11-01

    YBa2Cu3O7-x magnetometers have been made on 10 mm × 10 mm MgO substrates by directly coupling the magnetometer pick-up loop to a dc SQUID with narrow strip lines. The dc SQUIDs were made with YBa2Cu3O7-x step-edge Josephson junctions. The layout of the magnetometer pick-up loop was chosen as a compromise between maximizing the loop effective area and minimizing the loop inductance. The SQUID was designed to have LS~100 pH in order to obtain icons/Journals/Common/beta" ALT="beta" ALIGN="TOP"/>L = 2I0LS/icons/Journals/Common/Phi" ALT="Phi" ALIGN="TOP"/>0icons/Journals/Common/approx" ALT="approx" ALIGN="TOP"/>1 with the single-junction critical current I0~10 µA. We have made magnetometers with white noise levels down to 55 fT Hz-1/2 and a 1/f knee at 1 Hz (ac biased). Noise measurements were made on a field-cooled magnetometer. The noise measured at 1 Hz when cooled in `zero field' was 175 fT Hz-1/2. When cooled in magnetic fields of B = 50 µT and B = 100 µT we measured the noise at 1 Hz to be 430 fT Hz-1/2 and 1.3 pT Hz-1/2, respectively.

  7. Multistage Zeeman deceleration of metastable neon

    SciTech Connect

    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

    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.

  8. Fly on the Ceiling

    NSDL National Science Digital Library

    2012-10-30

    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.

  9. Flying qualities research challenges

    NASA Technical Reports Server (NTRS)

    Sliwa, Steven M.; George, Frank L.

    1987-01-01

    Traditional flying qualities requirements for airplane dynamics are based on airplane modal response characteristics derived from linear small-perturbation analysis. These requirements are supported by a large experimental data base. The challenge to the flying qualities community is to demonstrate how flying qualities, the control system and aircraft configuration are still closely linked. This is evident in the definition of flying qualities and, as far as pilots are concerned, that flying qualities are still the measure of overall design success.

  10. Virtual fly

    NSDL National Science Digital Library

    0000-00-00

    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 Â?HelpÂ? 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".

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

    SciTech Connect

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

    2011-12-10

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

  12. Purification and Liquefacttion of Neon Using a Helium Refrigeration Cycle

    NASA Astrophysics Data System (ADS)

    Boeck, S.

    2010-04-01

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

  13. Heritability and fitness-related consequences of squid personality traits

    Microsoft Academic Search

    D. L. SINN; L. A. APIOLAZA; N. A. MOLTSCHANIWSKYJ

    2006-01-01

    Dumpling squid, Euprymna tasmanica, show consistent individual differences in behaviour that can be classified according to indices reflecting shy-bold, activity and reactivity responses. Using crosses of wild-caught single males to multiple females with known behavioural phenotypes, this study estimated patterns of additive genetic and residual variance in these behavioural traits from offspring of squid in two contexts, a threat (antipredator)

  14. Chaos and phase locking in normal squid axons

    NASA Astrophysics Data System (ADS)

    Matsumoto, Gen; Aihara, Kazuyuki; Hanyu, Yoshiro; Takahashi, Nobuyuki; Yoshizawa, Shuji; Nagumo, Jin-ichi

    1987-08-01

    By using periodic current stimulation, chaotic potential responses could be evoked in squid axons immersed in normal seawater. the occurence of intermittent chaos arose through a subcritical period-doubling bifurcation, indicating some similarity of the dynamical structures between the Rayleigh-Bénard convection and the squid axon systems.

  15. Read-out electronics for DC squid magnetic measurements

    DOEpatents

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

    2002-01-01

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

  16. Estimating Orientation of Flying Fruit Flies

    PubMed Central

    Cheng, Xi En; Wang, Shuo Hong; Qian, Zhi-Ming; Chen, Yan Qiu

    2015-01-01

    The recently growing interest in studying flight behaviours of fruit flies, Drosophila melanogaster, has highlighted the need for developing tools that acquire quantitative motion data. Despite recent advance of video tracking systems, acquiring a flying fly’s orientation remains a challenge for these tools. In this paper, we present a novel method for estimating individual flying fly’s orientation using image cues. Thanks to the line reconstruction algorithm in computer vision field, this work can thereby focus on the practical detail of implementation and evaluation of the orientation estimation algorithm. The orientation estimation algorithm can be incorporated into tracking algorithms. We rigorously evaluated the effectiveness and accuracy of the proposed algorithm by running experiments both on simulation data and on real-world data. This work complements methods for studying the fruit fly’s flight behaviours in a three-dimensional environment. PMID:26173128

  17. Capacitively-Coupled SQUID Bias for Time Division Multiplexing

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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.

  18. Kinetics experiments on neon-like x-ray lasers

    SciTech Connect

    Fields, D.J.; Walling, R.S.; Fry, A.R.; Shimkaveg, G.M.; Phillips, T.W.; Osterheld, A.L.; MacGowan, B.J.; Da Silva, L.B.; Stewart, R.E.; Goldstein, W.H.; Matthews, D.L.; Eckart, M.J.

    1990-12-18

    Recent results from experiments with neon-like x-ray lasers are discussed. Lasing in an Ag amplifier is demonstrated. The strong J=2-1 transitions are shown to have large gains. A J=0-1 transition at 81.57 {Angstrom} is the shortest lasing transition yet observed in neon-like ions. A quasi-cw laser is demonstrated in experiments with germanium amplifiers. A substantial difference is shown to exist between the spectroscopy of lasers produced in exploding foils and slab targets. Experiments with over-ionized germanium lasers are also discussed.

  19. Triple Photoionization of Neon and Argon Near Threshold

    NASA Astrophysics Data System (ADS)

    Bluett, Jaques B.; Luki?, Dragan; Sellin, Ivan A.; Whitfield, Scott B.; Wehlitz, Ralf

    2003-05-01

    The threshold behavior of the triple ionization cross-section of neon and argon was investigated using monochromatized synchrotron radiation and ion time-of-flight spectrometry. The Ne^3+ and Ar^3+ cross-sections are found to follow the Wannier power law(G.H. Wannier, Phys. Rev. 90), 817 (1953). consistent with a Wannier exponent of 2.162 predicted by theory. This is also consistent with the findings of Samson and Angel(J.A.R. Samson and G.C. Angel, Phys. Lett. 61), 1584 (1988). for the case of Ne. In the case of argon we find a much shorter range of validity than for neon.

  20. Fast imaging of intact and shattered cryogenic neon pellets

    SciTech Connect

    Wang, Zhehui, E-mail: zwang@lanl.gov [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Combs, S. K.; Baylor, L. R.; Foust, C. R.; Lyttle, M. S.; Meitner, S. J.; Rasmussen, D. A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-11-15

    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.

  1. Boiling incipience and convective boiling of neon and nitrogen

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  2. Peaked density profiles due to neon injection on FTU

    NASA Astrophysics Data System (ADS)

    Mazzotta, C.; Bañón Navarro, A.; Gabellieri, L.; Marinucci, M.; Pucella, G.; Told, D.; Tudisco, O.; Apruzzese, G.; Artaserse, G.; Sozzi, C.; the FTU Team

    2015-07-01

    Neon injection in FTU can cause a spontaneous increase of the line-average density by a factor 2. The recent experiments were devoted to characterize the plasma response to the neon injection at different densities and plasma currents. A qualitative estimate from UV spectroscopy measurements indicates that the density behaviour cannot be attributed simply to the stripped electrons from the puffed impurity, but a modification of particle transport should be invoked in order to explain the spontaneous rise and the higher peaking. JETTO transport and GENE gyrokinetic codes analyses, as well as a calculation of the electron diffusion coefficients D and pinch velocity U, contribute to feature the peaking effect.

  3. The Ubiquitous SQUID: From Axions to Cancer

    NASA Astrophysics Data System (ADS)

    Clarke, John

    2011-03-01

    I briefly review the principles, practical implementation and applications of the dc SQUID (Superconducting QUantum Interference Device), an ultrasensitive detector of magnetic flux. Cosmological observations show that a major constituent of the universe is cold dark matter (CDM). A candidate particle for CDM is the axion which, in the presence of a magnetic field, is predicted to decay into a photon with energy given by the axion mass, ranging from 0.001 to 1 meV. The axion detector constructed at LLNL consists of a cooled, tunable cavity surrounded by a 7-T superconducting magnet. Photons from the axion decay would be detected by a cooled semiconductor amplifier. To search for the axion over an octave of frequency, however, would take two centuries. Now at the University of Washington, Seattle the axion detector will be upgraded by cooling it to 50 mK and installing a near-quantum limited SQUID amplifier. The scan time will be reduced by three orders of magnitude to a few months. In medical physics, we use an ultralow-field magnetic resonance imaging (ULFMRI) system with SQUID detection to obtain images in a magnetic field of 0.132 mT, four orders of magnitude lower than in conventional MRI. An advantage of low fields is that different types of tissue exhibit much greater contrast in the relaxation time T1 than in high fields. We have measured T1 in ex vivo specimens of surgically removed healthy and malignant prostate tissue. The percentage of tumor in each specimen is determined with pathology. The MRI contrast between two specimens from a given patient scales with the difference in the percentage of tumor; in healthy tissue T1 is typically 50 percent higher than in a tumor. These results suggest that ULFMRI with T1-weighted contrast may have clinical applications to imaging prostate cancer and potentially other types of cancer. Supported by DOE BES and HEP, and NIH

  4. Intrapopulation structure of winter-spawned Argentine shortfin squid, Illex argentinus

    E-print Network

    1 Intrapopulation structure of winter-spawned Argentine shortfin squid, Illex argentinus of the important commercial squid Illex argentinus were studied by using bio- logical data from about 25 thousand until April, composed predominantly of June- and July-hatched squid. Squid grow and mature rapidly

  5. Quantum dynamics in a camel-back potential of a dc SQUID E. Hoskinson1

    E-print Network

    Paris-Sud XI, Université de

    Quantum dynamics in a camel-back potential of a dc SQUID E. Hoskinson1 , F. Lecocq1 , N. Didier2 Josephson junctions (dc SQUID), with near-zero current bias and flux bias near half a flux quantum. We SQUID and the rf SQUID phase qubit have been extensively studied [2­6]. In each of these devices

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

    E-print Network

    Richards, Paul L.

    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

  7. Controlling Blow Flies 

    E-print Network

    Tomberlin, Jeffery K.

    2005-10-05

    Blow flies lay their eggs on animal remains and can spread disease. To control blow flies, it is important to remove dead animals and dispose of them properly, and to use effective insecticides when necessary....

  8. Black Flies: Simulium spp.

    NSDL National Science Digital Library

    0000-00-00

    A thorough resource about this annoying biting fly, including distribution, life cycle, damage caused, management, and some selected references. Several images are included, and personal recommendations for avoiding them. There is also a link to general biting fly management.

  9. Base distance optimization for SQUID gradiometers

    SciTech Connect

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

    1998-12-31

    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.

  10. Optogalvanic and optoacoustic detections in a neon positive column

    Microsoft Academic Search

    A. Sasso; M. G. di Vito; E. Arimondo

    1988-01-01

    The optogalvanic effect in the positive column of a neon discharge is investigated in combination with the simultaneous observations of the optoacoustic effect and the electroacoustic effect, a modification in the discharge temperature produced by an external electrical modulation of the current. The observations of current and power dissipated in the discharge are analyzed through a discharge model for the

  11. Quantum-corrected pair distribution function of liquid neon

    NASA Astrophysics Data System (ADS)

    Barocchi, F.; Neumann, M.; Zoppi, M.

    1985-06-01

    By means of computer simulation we have calculated the quantum-corrected pair distribution function g(r) of liquid neon up to the term ?6 of the Wigner-Kirkwood series expansion. The agreement between calculation and the experimental data at T~=35 K of De Graaf and Mozer is now, for the first time, satisfactory.

  12. Molecular Iodine Fluorescence Using a Green Helium-Neon Laser

    ERIC Educational Resources Information Center

    Williamson, J. Charles

    2011-01-01

    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…

  13. On the Appearance of Helium and Neon in Vacuum Tubes

    Microsoft Academic Search

    J. J. Thomson; HUBERT S. PATTERSON

    1913-01-01

    AT the last meeting of the Chemical Society, Sir William Ramsay, Prof. Collie, and Mr. Patterson described some experiments which they regard as proving the transmutation of other elements into helium and neon. I have been making experiments of a somewhat similar character for some time, and though the investigation is not yet finished, the results I have obtained up

  14. The NEON Aquatic Network: Expanding the Availability of Biogeochemical Data

    NASA Astrophysics Data System (ADS)

    Vance, J. M.; Bohall, C.; Fitzgerald, M.; Utz, R.; Parker, S. M.; Roehm, C. L.; Goodman, K. J.; McLaughlin, B.

    2013-12-01

    Aquatic ecosystems are facing unprecedented pressure from climate change and land-use practices. Invasive species, whether plant, animal, insect or microbe present additional threat to aquatic ecosystem services. There are significant scientific challenges to understanding how these forces will interact to affect aquatic ecosystems, as the flow of energy and materials in the environment is driven by multivariate and non-linear biogeochemical cycles. The National Ecological Observatory Network (NEON) will collect and provide observational data across multiple scales. Sites were selected to maximize representation of major North American ecosystems using a multivariate geographic clustering method that partitioned the continental US, AK, HI, and Puerto Rico into 20 eco-climatic domains. The NEON data collection systems and methods are designed to yield standardized, near real-time data subjected to rigorous quality controls prior to public dissemination through an online data portal. NEON will collect data for 30 years to facilitate spatial-temporal analysis of environmental responses and drivers of ecosystem change, ranging from local through continental scales. Here we present the NEON Aquatic Network, a multi-parameter network consisting of a combination of in situ sensor and observational data. This network will provide data to examine biogeochemical, biological, hydrologic and geomorphic metrics at 36 sites, which are a combination of small 1st/2nd order wadeable streams, large rivers and lakes. A typical NEON Aquatic site will host up to two in-stream sensor sets designed to collect near-continuous water quality data (e.g. pH/ORP, temperature, conductivity, dissolved oxygen, CDOM) along with up to 8 shallow groundwater monitoring wells (level, temp., cond.), and a local meteorological station (e.g. 2D wind speed, PAR, barometric pressure, temperature, net radiation). These coupled sensor suites will be complemented by observational data (e.g. water/sediment chemistry, aquatic organisms, geomorphology). The aquatic network will produce ~212 low-level data products for each site. NEON will produce several higher level data products such as measurements of whole-stream metabolism, gross primary productivity, ecosystem respiration, and fluxes of nitrogen, phosphorous and carbon that will enable users to analyze processes on a gross scale. These data may be integrated with NEON's terrestrial and airborne networks to bridge the gap between aquatic and terrestrial biogeochemical research. The NEON Aquatic Network is poised to greatly expand our ability to create more robust biogeochemical models. For example, hydrologic and stable isotope data will allow investigation of terrestrial-aquatic carbon flux. Constraints provided by NEON's terrestrial and atmospheric data concurrent with remotely sensed data will facilitate the scaling to regional and continental scales, potentially leading to greater accuracy in the global carbon budget. The NEON Aquatic Network represents a powerful tool that will give the scientific community access to standardized data over spatiotemporal scales that are needed to answer fundamental questions about natural ecological variability and responses to changes in the environment.

  15. Decoherence and Recoherence in a Vibrating RF SQUID

    E-print Network

    Eyal Buks; M. P. Blencowe

    2006-09-19

    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.

  16. Stochastic Resonance for a SQUID with Dichotomous Resistance

    NASA Astrophysics Data System (ADS)

    Li, Jing-Hui

    2014-03-01

    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).

  17. RF-SQUID to DC-SQUID upgrade of a 28-channel magnetoencephalography (MEG) system

    NASA Astrophysics Data System (ADS)

    Diekmann, V.; Jürgens, R.; Becker, W.; Elias, H.; Ludwig, W.; Vodel, W.

    1996-05-01

    A Dornier 28-channel magnetoencephalography (MEG) system equipped with RF-SQUIDs and control electronics made by CTF (Port Coquitlam, BC, Canada) was upgraded by replacing the RF-SQUIDs with DC-SQUIDs developed at the University of Jena, Germany. New preamplifiers were designed that emulate the function of the system's original RF amplifiers. This allowed the continuing use of the system's control electronics without any modification. Retaining these control devices was instrumental for preserving the system's unique ability to derive software-defined gradiometer measurements from its magnetometer signals, and also saved a considerable investment of control software tailored to the characteristics of these devices. The performance of the upgraded system compares favourably to that of other multichannel instruments; its software gradiometer channels typically attain an overall sensitivity of 0957-0233/7/5/017/img7 (an improvement by a factor of three over the original RF system) and suppress residual noise inside the shielded room by 40 to 60 dB. Also described are the procedures used to calibrate the system, to eliminate crosstalk between neighbouring channels, and to determine the coefficients for optimum suppression of ambient noise by the software gradiometer.

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

    NASA Technical Reports Server (NTRS)

    Zahnle, K.

    1991-01-01

    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.

  19. Development of a low temperature SQUID gradiometer for magnetic microcalorimeters

    NASA Astrophysics Data System (ADS)

    Oshima, T.; Tsuchiya, A.; Sato, K.; Yamasaki, N. Y.; Morooka, T.

    2006-04-01

    We will report on the performance of a first order SQUID gradiometer developed for the readout of the magnetic microcalorimeters. The SQUID is designed to operate at temperatures below 0.1 K with flux noise level lower than 1 ??0/?{Hz} in a magnetic field of 3.5 mT at its washers. It has a baseline of 500 ?m and washer size of 50 ?m in diameter. To produce an ambient magnetic field in a persistent current mode, field coils with a superconducting short equipped with a heater as a switch are integrated on the same chip. Care was taken to decrease the heat input generated by shunt resistors and cooling fins were attached to them to minimize the over-heating of the electrons in the shunts. In order not to degrade the performance by the readout circuit, the SQUID gradiometer is connected to and read out through a low noise series SQUID amplifier.

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

    E-print Network

    Hanlon, Roger T.

    2133 Introduction Cephalopods (squid, cuttlefish, octopus) can produce a variety of body patterns to the behavior of these animals (Young, 1971). Indeed, Octopus vulgaris can quickly learn to visually

  1. Nonstandard applications of superconducting quantum interferometers: SQUIDS (Review)

    SciTech Connect

    Odegnal, M.

    1985-01-01

    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.

  2. A Slice of Apple Fly

    NSDL National Science Digital Library

    2014-07-22

    In this activity, learners build an instrument for catching and observing flies. Learners act as entomologists, attract flies into a jar using a slice of apple, and then observe the flies' behavior. Learners distinguish between male and female flies and study fly reproduction. The learning time for this activity can vary significantly, depending on how long learners want to observe the flies. Learners release the flies outside at the end of the activity.

  3. SQUID-amplified photon detection: from cosmology to material science

    NASA Astrophysics Data System (ADS)

    Irwin, Kent

    2014-03-01

    Superconducting photon detectors amplified by SQUIDs are playing an increasingly important role in science ranging from cosmology to materials characterization. The most widely used superconducting photon detector uses a superconducting transition-edge sensor (TES), which is a superconducting film biased in the narrow transition region between the normal and superconducting state. The film is voltage biased, and the current flowing through it is measured with a SQUID. An incident photon increases the resistance of the TES, which reduces the current through the SQUID. Large arrays of SQUID-coupled TES detectors are read out by cryogenic multiplexing of the SQUIDs with a time-division, frequency-division, or code-division multiplexing scheme. SQUID-coupled TES detectors are now widely deployed in ground- and balloon-borne observatories to measure the cosmic microwave background (CMB) radiation. By measuring the power and the polarization of the CMB, new constraints have been placed on cosmological parameters, as well as the absolute masses and number of neutrino species. Experiments are now being conducted to search for the signature of gravitational waves in the polarization of the cosmic microwave background, which would provide strong evidence of inflation at GUT energy scales. Remarkably, very similar sensor arrays to those developed for CMB measurements can also be used for spectroscopic measurements at synchrotron and free-electron laser x-ray light sources. SQUID-coupled TES sensors provide spectroscopic resolution previously only achieved with dispersive detectors based on gratings and crystal diffraction, but with the high efficiency of semiconductor x-ray detectors. I will describe experiments using SQUID-coupled TES arrays for x-ray emission and x-ray absorption spectroscopy of materials, and plans to develop much larger arrays for next-generation light sources.

  4. Two-stage S-band DC SQUID amplifier

    Microsoft Academic Search

    Georgy V. Prokopenko; Dmitry V. Balashov; Sergey V. Shitov; Valery P. Koshelets; Jesper Mygind

    1999-01-01

    A 6 mm×6 mm chip comprising two identical DC SQUID based amplifiers (SQAs) has been designed, fabricated and tested as a two-stage RF amplifier in a frequency range 3.5-4.0 GHz. Each SQA consists of a double washer type DC SQUID with novel integrated input resonant circuit. The reflection coefficient of both input and output of the SQA has been measured

  5. Vigilance and antipredator responses of Caribbean reef squid

    Microsoft Academic Search

    Jennifer A. Mather

    2010-01-01

    Antipredator responses, especially those of open-ocean squid, have been seldom studied in the natural environment. Sepioteuthis sepioidea, observed by snorkellers near the shore in early morning\\/late afternoon, produced an average of eight moves of over 1?m per hour, apparently mostly antipredator behaviours. Close approaches by herbivorous parrotfish elicited no response in 74% of encounters; otherwise, squid produced agonistic zebra stripes

  6. Development of SQUID-Based System for Nondestructive Evaluation

    Microsoft Academic Search

    R. Nagendran; M. P. Janawadkar; M. Pattabiraman; J. Jayapandian; R. Baskaran; L. S. Vaidhyanathan; Y. Hariharan; A. Nagesha; M. Valsan; K. B. S. Rao; B. Raj

    2007-01-01

    This article describes the development of a superconducting quantum interference device (SQUID)-based system for nondestructive evaluation. The setup incorporates an in-house developed thin-film-based Nb SQUID with readout flux locked loop electronics and consists of a liquid helium cryostat with adjustable stand-off distance, a precision XY- thetas scanner for studying both flat and cylindrical samples, and a data acquisition system. The

  7. Quantum analysis of a linear DC SQUID mechanical displacement detector

    E-print Network

    M. P. Blencowe; E. Buks

    2007-07-19

    We provide a quantum analysis of a DC SQUID mechanical displacement detector within the sub-critical Josephson current regime. A segment of the SQUID loop forms the mechanical resonator and motion of the latter is transduced inductively through changes in the flux threading the loop. Expressions are derived for the detector signal response and noise, which are used to evaluate the position and force detection sensitivity. We also investigate cooling of the mechanical resonator due to back reaction noise from the detector.

  8. Flying Robots and Flying Cars Heinrich H. Blthoff

    E-print Network

    Flying Robots and Flying Cars Heinrich H. Bülthoff Biological Cybernetics Research at the Max Flying Robots -- Human Robot Interaction group at MPI Tübingen Flying Cars -- European Project (my. Robuffo Giordano Human Robot Interaction group Bilateral shared control of Flying Robots M. Cognetti, V

  9. Fly ash carbon passivation

    DOEpatents

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

    2013-05-14

    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.

  10. Development of 1.3GHz HTc rf SQUID

    NASA Astrophysics Data System (ADS)

    Liu, Xin-Yuan; Xie, Fei-Xiang; Meng, Shu-Chao; Dai, Yuan-Dong; Li, Zhuang-Zhi; Ma, Ping; Yang, Tao; Nie, Rui-Juan; Wang, Fu-Ren

    2004-01-01

    A new HTc rf SQUID working at around 1.3GHz has been developed to avoid electromagnetic interference such as growing mobile communication jamming. This new system works in a frequency range from 1.23 to 1.42GHz (centred at 1.3GHz), which is not occupied by commercial communication. The sensor used in the 1.3GHz rf SQUID is made of a HTc coplanar superconducting resonator and a large-area HTc superconducting film concentrator. We have achieved in the 1.3GHz HTc rf SQUID system a minimal flux noise of 2.5×10-5Phi0/(Hz)1/2 and a magnetic field sensitivity of 38fT/(Hz)1/2 in white noise range, respectively. The effective area of the concentrator fabricated on a 15×15mm2 substrate is 1.35mm2. It is shown that the 1.3GHz rf SQUID system has a high field sensitivity. Design and implementation of 1.3GHz HTc rf SQUID offers a promising direction of rf SQUID development for higher working frequency ranges.

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

    NASA Astrophysics Data System (ADS)

    Schimel, D.; Berukoff, S. J.

    2011-12-01

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

  12. Discovery of solar wind neon in the Allende meteorite

    NASA Technical Reports Server (NTRS)

    Heymann, D.; Palma, R. L.

    1986-01-01

    Insert gases have been measured in seven sieve fractions of a disaggregated sample of the Allende meteorite. The disaggregation was done by ultrasonic treatment in water and by freeze-thawing. This sample consititutes the first gas-rich portion known to occur in the Allende meteorite. The composition of the trapped neon is solar, i.e., Neon-B, and the gas-rich samples contain more trapped Ne-20 than Ar-36. The set of sieve fractions show an anticorrelation of Ne-20 content and grain size. Gas-richness seems to be quite common among the CV3 meteorites with Allende added to the earlier known cases of Mokoia, Vigarano, and Efremovka.

  13. Neon time-of-flight backscattering spectrometry for surface analysis 

    E-print Network

    Garcia, Richard Michael

    2001-01-01

    OF SCIENCE August 2001 Major Subject: Nuclear Engineering NEON TIME-OF-FLIGHT BACKSCATTERING SPECTROMETRY FOR SURFACE ANALYSIS A Thesis by RICHARD MICHAEL GARCIA Submitted to Texas AkM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE Approved as to style and content by: Ron R. Hart (Chair of Committee) Frederick R. Best (Member) Richard B. Gri fin (Member) Alan E. Waltar (Head of Department) August 2001 Major Subject: Nuclear Engineering...

  14. Optical Heterodyne Measurement of Neon Laser's Millimeter Wave Difference Frequency

    Microsoft Academic Search

    J. L. Hall; W. W. Morey

    1967-01-01

    We report detection and measurement of the millimeter wave difference frequency between two near laser lines at 1.152 ?. The two spectral transitions, separated by 2.26 Å, oscillate in pure neon in a single laser device, producing about 150 ?W total power in several longitudinal modes. The many resulting 51.3-kmc beat frequencies have been studied by optical heterodyne techniques. A

  15. [Warble fly: an update].

    PubMed

    Sol, J; Sampimon, O C

    1997-05-15

    The cycle of the warble fly, the possibilities for detection and treatment and the prevalence in Europe are described. In the Netherlands in 1953 a warble fly law was enacted. The eradication of warble fly in the Netherlands was completed in the early eighties. Therefore prevention of a reinfestation is necessary by control of imported cattle and of farms along the border with Belgium and Germany. PMID:9381455

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  17. The Electron Impact Excitation of Neon and Xenon

    NASA Astrophysics Data System (ADS)

    Gastineau, John Edward

    Absolute electron impact excitation optical cross sections of ninety-seven transitions in xenon have been measured using the optical method, over an energy range of 10 to 100 eV. The cross sections are generally pressure dependent over the range of 3 to below 0.10 mT, and are increasingly pressure dependent at electron energies above 50 eV. This is a much lower range for pressure effects than is seen in other gases. The apparent cross sections of the lowest lying p levels, configuration 5p('5)6p, labeled 2p in Paschen's notation, have been calculated from the appropriate optical cross sections. The low pressure limiting cross sections for the 2p(,1), 2p(,3), 2p(,6), 2p(,9), and 2p(,10) levels were reached. The apparent cross sections of xenon at energies well above threshold are generally an order of magnitude larger than those of helium and neon, with xenon cross sections being near 10('-18) cm('2). The xenon excitation functions are more sharply peaked than the functions of neon or helium. The cascade contributions at 3 mT to six (2p(,5-10)) levels were partially measured, and at 50 eV the apparent cross sections are 10-50% cascade. The form of the pressure dependence of the xenon 2p levels and of several cascade levels to the 2p levels were studied. All cross sections that were pressure dependent tended toward asymptotic limits at pressure of 2 to 3 mT. Radiation trapping of resonant levels was determined to be the dominate source of the pressure dependence, as the pressure dependence was made less severe by reducing the size of the collision chamber. The 2p levels, which are not resonant, are pressure dependent from receiving cascade from resonant levels. The neon 2p levels are similarly pressure dependent, chiefly from pressure dependent cascade from resonant levels. Absolute apparent cross sections for the 2p states were determined at pressures below 0.25 mT. The pressure dependence in neon is milder and occurs at higher pressure than in xenon. The decay components of several neon 2p and 2p cascade levels were studied with time resolved spectroscopy. Levels that showed pressure dependence in the above experiments also show significant decay components of lifetime more than 0.5 (mu)s.

  18. SQUID use for Geophysics: finding billions of dollars

    NASA Astrophysics Data System (ADS)

    Foley, Catherine

    2014-03-01

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

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

    E-print Network

    Wright, Dawn Jeannine

    in oceanic food webs. There is also a large commercial fishery for squid as they are highly prized by humans The Squid Dissection program at Hatfield Marine Science Center is designed to be a 50- minute lab

  20. SQUID detected NMR in microtesla magnetic fields

    NASA Astrophysics Data System (ADS)

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

    2004-09-01

    We have built an NMR system that employs a superconducting quantum interference device (SQUID) detector and operates in measurement fields of 2-25 ?T. 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 ?T 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.

  1. Activation of fly ash

    DOEpatents

    Corbin, David R. (New Castle, DE); Velenyi, Louis J. (Lyndhurst, OH); Pepera, Marc A. (Northfield, OH); Dolhyj, Serge R. (Parma, OH)

    1986-01-01

    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.

  2. A Better Fly Trap

    NSDL National Science Digital Library

    Lawrence Hall of Science

    1979-01-01

    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.

  3. Mutant Fruit Flies

    NSDL National Science Digital Library

    0000-00-00

    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.

  4. The UT 19-channel DC SQUID based neuromagnetometer.

    PubMed

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

    1991-01-01

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

  5. Detection of Magnetically-Tagged Antigens with a SQUID Microscope

    NASA Astrophysics Data System (ADS)

    Chemla, Y. R.; Grossman, H. L.; Clarke, John; Poon, Y. S.; Alper, M. D.; Stevens, R. C.

    2000-03-01

    We describe a novel immunoassay using a SQUID microscope to detect magnetically-tagged antigens. The SQUID microscope consists of a Superconducting QUantum Interference Device, cooled to 77K inside a vacuum enclosure, thermally isolated from a room-temperature sample which may be positioned to within 15? m of the SQUID. At this distance we are able to detect a dipole moment of 10-17 Am^2 in a 1 Hz bandwidth, corresponding to one single-domain 35nm magnetite nanoparticle. A substrate of liposomes labeled with the FLAG epitope is placed on the microscope and immersed in a solution of superparamagnetic nanoparticles coated with anti-FLAG antibodies. A pulse of magnetic field aligns the magnetic moments parallel to the SQUID. Subsequently, the SQUID detects the decay of the remanent magnetization of the magnetic tags bound to the antigens, whereas unbound magnetic nanoparticles relax very rapidly by Brownian rotation and do not contribute to the signal. We also explore the possible use of nanoparticles extracted from magnetotactic bacteria as magnetic tags.

  6. 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.

  7. Inspection of aircraft parts with high remanent magnetization by eddy current SQUID NDE

    Microsoft Academic Search

    M. V. Kreutzbruck; U. Baby; A. Theiss; M. Muck; C. Heiden

    1999-01-01

    We have developed an eddy current NDE system based on HTS rf SQUIDs as magnetic field sensors. Due to their high field sensitivity even at very low frequencies, SQUIDs are especially suitable for applications where a large eddy current penetration depth is required. We have used 3 GHz rf SQUIDs in our system made from YBCO thin films with a

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

    Microsoft Academic Search

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

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

  9. DEVELOPMENT AND APPLICATION OF AN OBJECTIVE METHOD FOR CLASSIFYING LONG-FINNED SQUID, LOLIGO PEALEI,

    E-print Network

    DEVELOPMENT AND APPLICATION OF AN OBJECTIVE METHOD FOR CLASSIFYING LONG-FINNED SQUID, LOLIGO PEALEI, INTO SEXUAL MATURITY STAGES WILLIAM K. MACY III! ABSTRACT An objective method of classifying long-finned squid by an appli- cation of the method. Each summer schools of long-finned squid, Loli- go pealei Lesueur, 1821

  10. 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

  11. FEEDING BEHAVIOR, FOOD CONSUMPTION, GROWTH, AND RESPIRATION OF THE SQUID LOLIGO OPALESCENS RAISED

    E-print Network

    FEEDING BEHAVIOR, FOOD CONSUMPTION, GROWTH, AND RESPIRATION OF THE SQUID LOLIGO OPALESCENS RAISED IN THE LABORATORY ANN C. HURLEY' ABSTRACT The squid Loligo opalescens was raised in the laboratory to a maximum age of 100 days on a diet of Artemia nauplii and adults. Newly hatched squid (2.7 mm mantle length) readily

  12. Halide Peroxidase in Tissues That Interact With Bacteria in the Host Squid Euprymna scolopes

    E-print Network

    McFall-Ngai, Margaret

    Halide Peroxidase in Tissues That Interact With Bacteria in the Host Squid Euprymna scolopes Andrea, a squid that maintains a beneficial association with the luminous bacterium Vibrio fischeri. Using three the activity of the squid enzyme with that of human myeloperoxi- dase. One of these methods, the diethanolamine

  13. Video Article Obtaining Hemocytes from the Hawaiian Bobtail Squid Euprymna scolopes and

    E-print Network

    McFall-Ngai, Margaret

    Video Article Obtaining Hemocytes from the Hawaiian Bobtail Squid Euprymna scolopes and Observing.V. (2010). Obtaining Hemocytes from the Hawaiian Bobtail Squid Euprymna scolopes and Observing between the Hawaiian bobtail squid, Euprymna scolopes and the bioluminescent bacterium Vibrio fischeri has

  14. Physics 6, 123 (2013) A SQUID Analog with a Bose-Einstein Condensate

    E-print Network

    Sato, Yuki

    2013-01-01

    Physics 6, 123 (2013) Viewpoint A SQUID Analog with a Bose-Einstein Condensate Yuki Sato Rowland SQUID C. Ryu, P. W. Blackburn, A. A. Blinova, and M. G. Boshier Phys. Rev. Lett. 111, 2013 ­ Published November 11, 2013 Superconducting Quantum Interference Devices (specifically, dc-SQUIDs) are the world

  15. TUNABLE ELECTRODYNAMIC ENVIRONMENT AND COULOMB BLOCKADE WITH 1D SQUID ARRAYS

    E-print Network

    Haviland, David

    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

  16. A MICROWAVE RESISTIVE SQUID FOR NOISE THERMOMETRY R. J. SOULEN and T. F. FINNEGAN

    E-print Network

    Paris-Sud XI, Université de

    305 A MICROWAVE RESISTIVE SQUID FOR NOISE THERMOMETRY R. J. SOULEN and T. F. FINNEGAN Institute for Basic Standards, National Bureau of Standards Washington, DC 20234, USA Résumé. 2014 Un SQUID température plus rapides. On décrit les perfor- mances d'un SQUID résistif travaillant à 10 GHz. La

  17. MFR PAPER 1275 Shortfin Squid, I/lex i/lecebrosus,

    E-print Network

    MFR PAPER 1275 Shortfin Squid, I/lex i/lecebrosus, Attacks on Trawl-Captured Fish SALVATORE A. TESTAVERDE Figure I.-Silver hake. Merluccius bilillearis, with wounds inflicted by shontin squid. commun.) increasingly large catches of shortfin squid, Illex illecebrosus, from the Gulf of Maine

  18. Recent Developments in the Squid, II/ex il/ecebrosus, Fishery

    E-print Network

    Recent Developments in the Squid, II/ex il/ecebrosus, Fishery of Newfoundland, Canada GEOFFREY V. HURLEY Introduction Since 1975 the nominal catches of the short-finned squid, fllex illece- brosus (Le was due in part to the worldwide development of fisheries for under- utilized marine species such as squid

  19. 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

  20. Role of Aerobic and Anaerobic Circular Mantle Muscle Fibers in Swimming Squid: Electromyography

    E-print Network

    Hynes, Wayne L.

    Role of Aerobic and Anaerobic Circular Mantle Muscle Fibers in Swimming Squid: Electromyography IAN muscle of squids and cuttle- fishes consists of distinct zones of aerobic and anaerobic muscle fibers with video footage were recorded from brief squid Lolli- guncula brevis (5.0­6.8 cm dorsal mantle length, 10

  1. Ontogenetic Changes in Fibrous Connective Tissue Organization in the Oval Squid, Sepioteuthis

    E-print Network

    Kier, William M.

    Ontogenetic Changes in Fibrous Connective Tissue Organization in the Oval Squid, Sepioteuthis lessoniana, the oval squid. Outer tunic fiber angle (the angle of a tunic collagen fiber relative to the long axis of the squid) decreased from 33.5° in newly hatched animals to 17.7° in the largest animals

  2. 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

  3. 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

  4. Although there are similarities in reproductive behavior among several squid species, our obser-

    E-print Network

    Although there are similarities in reproductive behavior among several squid species, our obser earlier who reported 12-15 pairs of squids in a semicircle (Turcol ), indi- cate that the social structure:53-57. 1965. Observations on the mating behavior of the squid Sepioteuthis sepioidea. Bull. Mar. Sci. 15

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

    E-print Network

    Ruby, Edward G.

    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

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

    E-print Network

    McFall-Ngai, Margaret

    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 sepiolid squids (Cephalopoda: Sepiolidae), and luminous bacteria (from the genera Vibrio and Photobacterium

  7. A 200 h two-stage dc SQUID amplifier for resonant gravitational wave detectors

    E-print Network

    A 200 h two-stage dc SQUID amplifier for resonant gravitational wave detectors Andrea Vinante1 commercial chips a two-stage dc Superconducting Quantum Interference Device (SQUID) was developed in order to be used as low noise amplifier on the resonant gravitational wave detector AURIGA. The SQUID was coupled

  8. 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

  9. Quantum phase transition and Coulomb blockade with one-dimensional SQUID arrays

    E-print Network

    Haviland, David

    Quantum phase transition and Coulomb blockade with one-dimensional SQUID arrays Michio Watanabe a-dimensional arrays of small-capacitance super- conducting quantum interference devices (SQUIDs), where an external; Fig. 1. A scanning electron micrograph of a one-dimensional SQUID array. The electromagnetic

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

    E-print Network

    Loss, Daniel

    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

  11. Tunable Electrodynamic Environment and Coulomb Blockade with 1D SQUID Arrays

    E-print Network

    Haviland, David

    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

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

    E-print Network

    Zok, Frank

    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

  13. Stabilization and optimization of a two-stage dc SQUID coupled to a high Q resonator

    E-print Network

    1 Stabilization and optimization of a two-stage dc SQUID coupled to a high Q resonator Andrea Padova and INFN, Sezione di Padova, Via Marzolo 8, I-35131, Padova, Italy Abstract A two-stage dc SQUID the behaviour of the SQUID on a resonant gravitational wave detector. A capacitive damping network

  14. Low field DC SQUID nuclear magnetic resonance on single crystal UPt3

    E-print Network

    Le Roy, Robert J.

    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

  15. A modular low noise 7-channel SQUID-magnetometer

    SciTech Connect

    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

    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.

  16. Flux noise in SQUIDs: Electron versus nuclear spins

    NASA Astrophysics Data System (ADS)

    de Sousa, Rogerio; Laforest, Stephanie

    2015-03-01

    Superconducting Quantum Interference Devices (SQUIDs) are limited by intrinsic flux noise whose origin is unknown. We develop a method to accurately calculate the flux produced by spin impurities in realistic superconducting thin film wires, and show that the flux produced by each spin is much larger than anticipated by former calculations. Remarkably, the total flux noise power due to electron spins at the thin side surface of the wires is found to be of similar magnitude as the one due to electrons at the wide top surface of the wires. In addition, flux noise due to lattice nuclear spins in the bulk of the wires is found to be a sizable fraction of the total noise for some SQUID geometries. We discuss the relative importance of electron and nuclear spin species in determining the total noise power, and propose strategies to design SQUIDs with lower flux noise. We acknowledge support from the Canadian agency NSERC through its Discovery and Engage programs.

  17. Signal detection in l/f noise of SQUID magnetometers

    NASA Technical Reports Server (NTRS)

    Cabrera, B.; Anderson, J. T.

    1978-01-01

    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.

  18. Application of SQUIDs for registration of biomagnetic signals

    NASA Astrophysics Data System (ADS)

    Voitovych, I. D.; Primin, M. A.; Sosnytskyy, V. N.

    2012-04-01

    Supersensitive magnetometric systems based on low-temperature SQUIDs have been designed to conduct research in cardiology (magnetocardiography) and to examine distribution of magnetic nanoparticles in biologic objects. Such SQUID magnetometric systems are distinguished by their noise immunity enabling research in nonscreened rooms. High repeatability of research outcomes has been confirmed. The use of magnetocardiographic systems has permitted a new screening information technology to be developed to diagnose heart diseases at early stages. Magnetic imaging of heart's action currents is an ideal way to test local electrical heterogeneity of myocardium. It is shown that magnetocardiography has a significant potential for both basic science of analysis of heart's biosignals and clinical cardiologic practice. A SQUID magnetometric system measuring magnetic signals radiated by the organs of laboratory animals is described. Information technology for automatic recording and transforming magnetometric data has been developed; the measurement of signals over rats' livers while injecting intravenously the nanoparticles of iron oxides and lead solutions are presented.

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

    E-print Network

    Graham, David W.

    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

  20. The melting curve of neon at high pressure W. L. Vos and J. A. Schouten

    E-print Network

    Vos, Willem L.

    from the point of view of melting, the most inter- esting elements are the rare gasesThe melting curve of neon at high pressure W. L. Vos and J. A. Schouten van der Waals Laboratorium October 1990; accepted 19 November 1990) We have measured the melting curve of neon to 54.5 kbar and 328 K

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

    Microsoft Academic Search

    D. Porcelli; G. J. Wasserburg

    1995-01-01

    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

  2. LBNL-42730 1 Collisional Perturbation of States in Atomic Ytterbium by Helium and Neon

    E-print Network

    Budker, Dmitry

    LBNL-42730 1 Collisional Perturbation of States in Atomic Ytterbium by Helium and Neon D, CA 94720 Results of an investigation of collisional de-excitation of the metastable 6s6p 3 P0 state in atomic ytterbium by helium and neon buffer gases are reported. We find upper limits for the quenching

  3. HIGH RESOLUTION OPTICAL SPECTROSCOPY IN NEON USING A TUNABLE LASER AND AN EXCITED ATOMIC BEAM

    E-print Network

    Boyer, Edmond

    L-161 HIGH RESOLUTION OPTICAL SPECTROSCOPY IN NEON USING A TUNABLE LASER AND AN EXCITED ATOMIC BEAM Résumé. 2014 La structure hyperfine de trois raies d'absorption du néon a été étudiée à l'aide d'un laser absorption lines of neon have been investigated using a single mode tunable dye laser illuminating an atomic

  4. In situ measurements of neon in the thermosphere

    NASA Technical Reports Server (NTRS)

    Potter, W. E.; Kayser, D. C.

    1976-01-01

    The open source neutral mass spectrometer on the Atmosphere Explorer-C satellite has measured neon in the thermosphere. The absolute density of Ne is close to that predicted by using the ground level fraction by volume of Ne along with the assumption of diffusive equilibrium above 100 km. Data is presented for both geomagnetically quiet and disturbed circular orbits. At 290 km, a typical low latitude value of Ne is 3.0 x 10 to the 4th/cu cm. At this altitude Ne appears to be predominantly controlled by temperature except during magnetic disturbances, when offsetting forces due to wind systems may be present.

  5. Self-broadening of non-resonance ? - ? neon lines

    Microsoft Academic Search

    P. J. Leo; D. F. T. Mullamphy; G. Peach; V. Venturi; I. B. Whittingham

    1996-01-01

    Quantum close-coupled calculations of the collisional self-broadening of neon lines involving transitions whose lower level is either a metastable or intercombination level, 0953-4075\\/29\\/20\\/014\\/img8 and 0953-4075\\/29\\/20\\/014\\/img9, and upper level is 0953-4075\\/29\\/20\\/014\\/img10, 0953-4075\\/29\\/20\\/014\\/img11 or 0953-4075\\/29\\/20\\/014\\/img12 are presented for temperatures of 77 and 273 K. These calculations are based on the quantum-mechanical impact theory of Baranger in which the interatomic interaction is represented

  6. The study of photoionization of neon-like Ar IX

    NASA Astrophysics Data System (ADS)

    Liang, Liang; Chao, Zhou; Xie, Zun-Xian

    2009-02-01

    The photoionization of the ground state of neon-like is investigated and the autoionizing spectrum of 2 s22 p52P 1/2ns, nd and 2 s2 p62S 1/2np Rydberg series of Ar IX are studied by using the Breit-Pauli Hamiltonian within the R-matrix theory combine with the QB method of Quigly-Berrington [L. Quigley, K.A. Berrington, J. Pelan, Comput. Phys. Commun. 144 (1998) 225]. We predict the energies and widths of four Rydberg series of Ar IX.

  7. Theoretical dielectric satellite lines of the neon X resonance line

    SciTech Connect

    Bhalla, C.P.; Karim, K.R.

    1986-08-01

    Calculations of the atomic parameters for the dielectric satellite lines of the Ne X resonance line are presented. These satellite lines correspond to transition from doubly excited states of heliumlike neon with electron configurations n-italicl-italic n-italic'l-italic'. The values of n-italic and n-italic' considered in this paper are 2, 3, and 4 with all allowed values of l-italic and l-italic'. The atomic model used in the present calculation is the self-consistent Hartree--Fock--Slater model with the inclusion of effects arising from the spin-orbit coupling and the electron configuration interaction.

  8. Squid detected NMR and MRI at ultralow fields

    DOEpatents

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

    2008-12-16

    Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

  9. Post-spawning egg care by a squid.

    PubMed

    Seibel, Brad A; Robison, Bruce H; Haddock, Steven H D

    2005-12-15

    Gonatus onyx is one of the most abundant cephalopods in the Pacific and Atlantic Oceans and is an important prey species for a variety of vertebrate predators, but a full understanding of its life history has been hampered because spawning occurs at great depths, where observation is difficult. Here we describe post-spawning egg care, or brooding, in this deep-sea squid. Our finding is unexpected because this behaviour differs from the reproductive habits of all other known squid species. PMID:16355206

  10. SQUID-based Resonant Detection of Axion Dark Matter

    E-print Network

    Popov, Vladimir

    2014-01-01

    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.

  11. Polarization rotation by an rf-SQUID metasurface

    E-print Network

    Caputo, J -G; Maimistov, A I

    2015-01-01

    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.

  12. Detecting in-situ active corrosion by a SQUID magnetometer

    NASA Astrophysics Data System (ADS)

    Li, Delin; Ma, Yupei; Flanagan, William F.; Lichter, Barry D.; Wikswo, John P.

    1995-09-01

    The magnetic field distributions above the surface of in-situ active corroding 2024-T3 and 7075-T6 aircraft aluminum alloy plates have been measured using a high-resolution superconducting quantum interference device (SQUID) magnetometer. The magnetic field distributions and their variation with time are clearly different for the two aluminum alloys in an identical solution and for 2024-T3 in two different solutions. It is believed that these results demonstrate theability of SQUID to noninvasively detect in-situ active corrosion in aircraft aluminum alloys in a way that present corrosion-detection methods do not allow.

  13. Squid detected NMR and MRI at ultralow fields

    DOEpatents

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

    2007-05-15

    Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

  14. A SIMPLE ULTRA HIGH RESOLUTION SQUID RESISTANCE BRIDGE B.R. Barnard and A.D. Caplin

    E-print Network

    Paris-Sud XI, Université de

    A SIMPLE ULTRA HIGH RESOLUTION SQUID RESISTANCE BRIDGE B.R. Barnard and A.D. Caplin Physics performance improves on that of the conventional SQUID potentiometric circuit by up to two orders of magnitude circuit for the measurement of small resistances with a SQUID is shown in figure la : the SQUID

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

    E-print Network

    Le Roy, Robert J.

    A simple three-channel dc SQUID system using time domain multiplexing M. Mück and M. Korn Justus) Conventional multichannel superconducting quantum interference device (SQUID) systems require a SQUID read-out circuit for each channel, as well as many wires connecting each individual SQUID and feedback coil

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

    E-print Network

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

    2010-10-21

    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.

  17. Operation MexFly

    NSDL National Science Digital Library

    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

    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.

  18. Venus fly trap

    NSDL National Science Digital Library

    Paul Lenz (None; )

    2006-01-26

    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.

  19. Fat Fruit Flies

    E-print Network

    Hacker, Randi

    2010-08-11

    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 ...

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

    Microsoft Academic Search

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

    2008-01-01

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

  1. Electron-impact excitation of neon and xenon

    SciTech Connect

    Gastineau, J.E.

    1986-01-01

    Absolute electron impact excitation optical cross sections of 97 transitions in xenon were measured, using the optical method, over an energy range of 10 to 100 eV. The cross sections are generally pressured-dependent over the range of 3 to below 0.10 mT, and are increasingly pressured-dependent at electron energies about 50 eV. This is a much lower range for pressure effects than is seen in other gases. The apparent cross sections of the lowest-lying p levels, configuration 5p/sup 5/6p, labeled 2p in Paschen's notation, were calculated from the appropriate optical cross sections. The form of the pressure dependence on the xenon 2p levels and of several cascade levels to the 2p levels were studied. All cross sections that were pressure dependent tended toward asymptotic limits at pressure of 2 to 3 mT. The neon 2p levels are similarly pressure-dependent, chiefly from pressure-dependent cascade from resonant levels. Absolute apparent cross sections for the 2p states were determined at pressures below 0.25 mT. The pressure dependence in neon is milder and occurs at higher pressure than in xenon.

  2. New Design of Neon Refrigerator for Hts Power Machines

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Hirai, H.; Takaike, A.; Hirokawa, M.; Aizawa, Y.; Kamioka, Y.; Okamoto, H.; Hayashi, H.; Shiohara, Y.

    2010-04-01

    In 2007, we developed a prototype refrigerator with a small turbo-expander to provide adequate cooling power (2 kW at 70 K) for HTS (High Temperature Superconductor) power machines. The reverse-Brayton cycle with neon gas as a working fluid was adopted in the refrigerator. The prototype refrigerator does not have enough COP (Coefficient of Performance) for practical HTS applications, and the purpose of this study is to research the information required for designing a new neon refrigerator with improved performance. We take the same refrigeration cycle and working fluid as the prototype one adopted, but a lower process pressure of 1 MPa/0.5 MPa is chosen instead of 2 MPa/1 MPa. The lower process pressure is required by the turbo-compressor design and the refrigeration process is analyzed by using a newly developed process simulator. Also, a heat-exchanger configuration is studied to make the refrigerator size small. The new refrigerator will have a cooling power of 2.5 kW at 65 K, and a COP of 0.06 at 80 K.

  3. Ever Fly a Tetrahedron?

    NSDL National Science Digital Library

    Kenneth King

    2004-01-01

    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.

  4. Just Let Me Fly

    Microsoft Academic Search

    Jim McGovern

    2011-01-01

    ‘Just Let Me Fly’ is a three act play by Jim McGovern. The underlying genre is tragedy with some dry humour and incidental music. The main theme is academic rivalry and the feeling of being repressed or bullied. The context is a department of aeronautical engineering at a university. An audio play variant is also available: ‘Fly Faster.’\\u000aThe main

  5. NEON: Transforming Environmental Data into Free, Open Information

    NASA Astrophysics Data System (ADS)

    Wee, B.

    2010-12-01

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

  6. A review of SQUID magnetometry applied to nondestructive evaluation

    Microsoft Academic Search

    Harold Weinstock; Bolling AFB

    1991-01-01

    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.

  7. Neritic squid resources and cuttlefish resources in Japan

    Microsoft Academic Search

    Yutaka Natsukari; Masatoki Tashiro

    1991-01-01

    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

  8. Metal detector based on high- T c RF SQUID

    Microsoft Academic Search

    D. F He; M. Yoshizawa

    2002-01-01

    Metal detector has many applications in food industries, wood board plants, safety security and landmine searching. Using eddy-current method, we constructed a metal detector based on high-Tc RF SQUID, and aluminum particle as small as 10 mg could be easily detected. A small ferrous particle in food wrapped by aluminum film could also be detected when a lower excitation frequency

  9. A fully portable, cryocooler-based HTS SQUID NDE instrument

    Microsoft Academic Search

    C. Carr; J. C. Macfarlane; G. B. Donaldson

    2003-01-01

    We have recently introduced a novel cryocooler-based HTS SQUID NDE instrument. The system incorporates a closed-cycle cooler that is connected to the inner and outer copper thermal batteries which then allows simultaneous cooling of both masses. Once the inner has been cooled to a temperature of approximately 40 K and the outer to a slightly higher temperature of around 70

  10. A dc SQUID based low-noise 4 GHz amplifier

    Microsoft Academic Search

    Georgy V. Prokopenko; Sergey V. Shitov; Valery P. Koshelets; Dmitry B. Balashov; Jesper Mygind

    1997-01-01

    The dc SQUID based RF amplifier (SQA) looks very attractive as an IF amplifier for integration with a SIS mixer and a flux-flow oscillator (FFO) in a fully superconducting submillimeter wave receiver suitable for space applications. Important advantages of the SQA are its low noise, extremely low power consumption, and complete compatibility with the fabrication process currently used for SIS

  11. Crystallographic Study of the LUMI Intermediate of Squid Rhodopsin

    PubMed Central

    Murakami, Midori; Kouyama, Tsutomu

    2015-01-01

    Upon absorption of light, the retinal chromophore in rhodopsin isomerizes from the 11-cis to the trans configuration, initiating a photoreaction cycle. The primary photoreaction state, bathorhodopsin (BATHO), relaxes thermally through lumirhodopsin (LUMI) into a photoactive state, metarhodopsin (META), which stimulates the conjugated G-protein. Previous crystallographic studies of squid and bovine rhodopsins have shown that the structural change in the primary photoreaction of squid rhodopsin is considerably different from that observed in bovine rhodopsin. It would be expected that there is a fundamental difference in the subsequent thermal relaxation process between vertebrate and invertebrate rhodopsins. In this work, we performed crystallographic analyses of the LUMI state of squid rhodopsin using the P62 crystal. When the crystal was illuminated at 100 K with blue light, a half fraction of the protein was converted into BATHO. This reaction state relaxed into LUMI when the illuminated crystal was warmed in the dark to 170 K. It was found that, whereas trans retinal is largely twisted in BATHO, it takes on a more planar configuration in LUMI. This relaxation of retinal is accompanied by reorientation of the Schiff base NH bond, the hydrogen-bonding partner of which is switched to Asn185 in LUMI. Unlike bovine rhodopsin, the BATHO-to-LUMI transition in squid rhodopsin was accompanied by no significant change in the position/orientation of the beta-ionone ring of retinal. PMID:26024518

  12. HfTi-nanoSQUID gradiometers with high linearity

    NASA Astrophysics Data System (ADS)

    Bechstein, S.; Ruede, F.; Drung, D.; Storm, J.-H.; Kieler, O. F.; Kohlmann, J.; Weimann, T.; Schurig, T.

    2015-02-01

    We have developed a family of HfTi nanoSQUID gradiometers for different applications. These Nb-based nanoSQUIDs contain overdamped superconductor-normal conductor-superconductor (SNS) Josephson junctions with HfTi as a normal conducting barrier. The lateral dimensions of the junctions are about 200 nm × 200 nm, and the barrier thickness is nominally 30 nm. In order to enhance their practical use, the nanoSQUIDs are implemented with gradiometric SQUID and feedback loops, gradiometric transformers, and rf filters. The devices can be operated in an excitation field of up to a few mT with very low levels of nonlinearity. Due to the small loop size and the resulting low loop inductance, a white noise level down to 110 n?0/?Hz was achieved. The 1/f noise with a typical corner frequency below 1 kHz is dominated by critical current fluctuations. It can be reduced by applying bias reversal. A noise level of 600 n?0/?Hz was achieved at 1 Hz in a two-stage flux locked loop with bias reversal.

  13. Deterministic prediction and chaos in squid axon response

    NASA Astrophysics Data System (ADS)

    Mees, A.; Aihara, K.; Adachi, M.; Judd, K.; Ikeguchi, T.; Matsumoto, G.

    1992-09-01

    We make deterministic predictive models of apparently complex squid axon response to periodic stimuli. The result provides evidence that the response is chaotic (and therefore partially predictable) and implies the possibility of identifying deterministic chaos in other kinds of noisy data even when explicit models are not available.

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

    SciTech Connect

    Kleiner, Reinhold; Koelle, Dieter; Clarke, John

    2007-01-15

    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.

  15. SQUID-Based Low Field MRI System for Small Animals

    Microsoft Academic Search

    Junichi Hatta; Masakazu Miyamoto; Yoshiaki Adachi; Jun Kawai; Gen Uehara; Hisashi Kado

    2011-01-01

    Low field MRI and MEG are based on the ability of SQUID sensors to detect femtotesla magnetic fields. We are now developing a low field MRI system which can be integrated with the MEG system for small animals. The fast switching of the po- larizing field inherently induces large transient signals in low field MRI experiments. We have optimized our

  16. Magnetic biosensor using a high transition temperature SQUID

    NASA Astrophysics Data System (ADS)

    Grossman, Helene Lila

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

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

    PubMed

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

    2011-04-01

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

  18. Squid dances: an ethogram of postures and actions of Sepioteuthis sepioidea squid with a muscular hydrostatic system

    Microsoft Academic Search

    Jennifer A. Mather; Ulrike Griebel; Ruth A. Byrne

    2010-01-01

    A taxonomy of the movement possibilities for any species, within the constraints of its neural and skeletal systems, should be one of the foundations of the study of its behaviour. Caribbean reef squid, Sepioteuthis sepioidea, appear to have many degrees of freedom in their movement as they live in a three-dimensional habitat and have no fixed skeleton but rather a

  19. Mechanism of the tunable structural color of neon tetra

    NASA Astrophysics Data System (ADS)

    Yoshioka, Shinya

    2010-03-01

    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).

  20. Continued investigation of the atomic physics of flashlamp pumped cesium-neon lasers

    NASA Astrophysics Data System (ADS)

    Chang, C. S.

    1983-05-01

    In the present report, we are primarily concerned with atomic processes in a high pressure gas discharge. The theoretical endeavor is highlighted in a detailed calculation of spectral line profile, which are essential to meaningfully model an arc lamp performance. We also examine the effect of neon as a buffer gas in a high pressure cesium discharge tube. Under the conduction of comparable cesium and neon pressures, we concluded that neon buffer gas is beneficial to the overall lamp performance. The detailed discussion can be found in Reference 2.

  1. Use of activated charcoal for the purification of neon in the CLEAN experiment

    NASA Astrophysics Data System (ADS)

    Harrison, M. K.; Lippincott, W. H.; McKinsey, D. N.; Nikkel, J. A.

    2007-01-01

    Passage of neon gas through activated charcoal is planned to be the primary method of removing impurities from the liquid neon scintillator in the CLEAN experiment. In order to quantify this technique, the breakout curves for hydrogen, nitrogen, argon and krypton impurities in neon-saturated activated charcoal were measured. Adsorption coefficients and the number of theoretical stages were measured for hydrogen in the temperature range between 300 and 80 K, nitrogen between 300 and 200 K, and argon between 300 and 190 K. The adsorption coefficient for krypton was measured at 300 K.

  2. 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.

  3. Quadrupole collectivity of neutron-rich Neon isotopes

    E-print Network

    R. R. Rodriguez-Guzman; J. L. Egido; L. M. Robledo

    2003-02-04

    The angular momentum projected Generator Coordinate Method, with the quadrupole moment as collective coordinate and the Gogny force (D1S) as the effective interaction, is used to describe the properties of the ground state and low-lying excited states of the even-even Neon isotopes $^{20-34}$Ne, that is, from the stability valley up to the drip-line. It is found that the ground state of the N=20 nucleus $^{30}$Ne is deformed but to a lesser extent than the N=20 isotope of the Magnesium. In the calculations, the isotope $^{32}$Ne is at the drip-line in good agreement with other theoretical predictions. On the other hand, rather good agreement with experimental data for many observables is obtained.

  4. Nitrogen and neon retention in plasma-facing materials

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

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

  5. Research Into a Neon Spectral Line Profile of Dusty Plasma

    E-print Network

    Pikalev, Aleksandr

    2014-01-01

    Ordered dusty structures influence plasma conditions. This influence can be revealed, when plasma spectral characteristics change, as dusty particles are injected. For example, a variation in the atomic temperature leads to a variation in the profiles of spectral lines. We studied the profile of a 585 nm neon spectral line in the dusty structures. The structures levitated in a positive column of a glow discharge at a pressure of 50-150 Pa and with a current of 1-9 mA. We scanned the profile with the use of a Fabry-Perot interferometer, by changing the air pressure between the interferometer mirrors. To process the data, a special algorithm was developed. The algorithm is resistant to a noise and a scanning speed instability. We have found an upper bound of the impact of dusty structures on the profile width. The appearance of macroparticles changes the atomic plasma temperature less than by 10 K.

  6. Solid neon moderated electrostatic or magnetic positron beam

    SciTech Connect

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

    1991-12-31

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

  7. Solid neon moderated electrostatic or magnetic positron beam

    SciTech Connect

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

    1991-01-01

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

  8. Single fly tethered paradigms.

    PubMed

    van Swinderen, Bruno

    2011-12-01

    The most successful approaches for studying visual perception and visual learning in Drosophila have been single fly paradigms in which tethered individuals respond to different visual stimuli, as described here. The equipment and protocols involved are quite sophisticated and differ depending on whether behavior or electrophysiology will be pursued. For either approach, flies must first be secured to a metal wire. This is typically performed by first cooling flies down to 4°C and then gluing them to a copper or tungsten wire with ultraviolet (UV)-activated cement. For electrophysiology, tethering requires a few extra steps to accommodate the placement of electrodes. Prepared individuals are then placed inside a cylindrical arena where images can be presented, or in front of a computer screen or even in front of a laptop. Flight dynamics or brain activity in response to visual stimuli is recorded by using a variety of specialized and/or commercially available electronic devices. PMID:22135659

  9. Flies and the mouth.

    PubMed

    Hassona, Yazan; Scully, Crispian; Aguida, Miranda; de Almeida, Oslei Paes

    2014-05-01

    Oral infections caused by flies are rarely encountered in clinical practice, and consequently, there is a paucity of information in the medical and dental literature about these conditions. In the present article, we present a concise review on oral myiasis or fly-blown disease. A variety of fly species can infest the oral tissues and produce an exotic clinical picture. Oral myiasis is mainly encountered in the tropics and subtropics, but can also be encountered in the western part of the world due to the increase of globalization, immigration, and global warming. Commonly-reported symptoms of oral myiasis include pain, swelling, itchy sensation, and feeling of something moving in the mouth. The surgical debridement of infected tissue with the removal of maggots is the treatment of choice in most cases of oral myiasis. PMID:24574273

  10. Interactive Fly: Maternally transcribed genes

    NSDL National Science Digital Library

    PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

    2006-11-13

    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.

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

    E-print Network

    Podpaly, Yuri Anatoly

    2007-01-01

    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 ...

  12. CRISSY PASCUAL / Union-Tribune Bruce Nauman's sculpture in neon, "Vices and

    E-print Network

    Bewley, Thomas

    CRISSY PASCUAL / Union-Tribune Bruce Nauman's sculpture in neon, "Vices and Virtues," switches Fleischner's "La Jolla Project" (1984) ­ Its 71 blocks of pink and gray granite are like sculptural building

  13. Effect of metastable neon atoms in a positive column of glow discharge with dust particles

    NASA Astrophysics Data System (ADS)

    Shumova, V. V.; Polyakov, D. N.; Vasilyak, L. M.

    2014-12-01

    The diffusion/drift model of the positive column of glow discharge in neon was used for the analysis of the role of neon metastable atoms in the interaction between neon plasma and dust particles. The radial profiles of electrons and metastable atoms were simulated in the typical range of neon pressure and discharge current where dust particles may form dense dust structures changing the plasma properties. The results showed the nonlocal effect of dust particles on the plasma composition. Within the dust structure, the metastable atom concentration was shown to be higher than in the discharge without dust particles at the same discharge parameters; the ratio of concentrations of metastable atoms and electrons may increase with increasing dust particle concentration in a certain range of discharge parameters. The partial contribution of metastable atoms to the ionization was found to be higher than their losses on the surface of dust particles and increased when the gas pressure was increased.

  14. 2012 National Ecological Observatory Network, Inc. ALL RIGHTS RESERVED. An inside-out look at NEON

    E-print Network

    in Environmental Sciences. Washington DC: National Academies Press. NRC (National Research Council). 2003. NEON: Addressing the Nation's Environmental Challenges. Washington DC: National Academies Press. #12;© 2012, 3 large rivers, 8 lakes 4. STREON sites (10): Experiments in nutrient

  15. Positron scattering on helium, neon and argon above 4 eV

    Microsoft Academic Search

    B. Jaduszliwer; D. A. L. Paul

    1974-01-01

    The authors have measured the transmission of a positron beam through helium, neon and argon gases from 4 eV up to the positronium\\u000a formation thresholds. A variable longitudinal magnetic field affects the transmission and allows some degree of phase shift\\u000a separation, analogously to the performance of an angular distribution experiment. The results for neon and argon are presented.

  16. The Mid and Near-Infrared Spectra of Water and Water Dimer Isolated in Solid Neon

    Microsoft Academic Search

    D. Forney; M. E. Jacox; W. E. Thompson

    1993-01-01

    Spectra have been obtained between 700 and 8000 cm-1 for H216O, and between 700 and 5000 cm-1 for deuterium and\\/or oxygen-18-enriched water, trapped in solid neon at approximately 5 K. Samples with Ne:water mole ratios between 400 and 6400 were studied. As in the heavier rare-gas solids, isolated water molecules can undergo relatively free rotation in solid neon, and nuclear

  17. Emission anomalous optical magnetic resonances in a mixture of even neon isotopes

    SciTech Connect

    Saprykin, E. G.; Sorokin, V. A., E-mail: Vlad_sorokin@ngs.ru; Shalagin, A. M. [Siberian Branch, Russian Academy of Sciences, Institute of Automation and Electrometry (Russian Federation)

    2013-04-15

    Unusual resonances have been detected in the dependence of the discharge glow in neon on the longitudinal magnetic field. The resonances appear in fairly high magnetic fields and are observed only at low gas pressures and exclusively in a mixture of {sup 20}Ne and {sup 22}Ne isotopes. This phenomenon is an evidence of collective resonant radiation processes involving atoms of different neon isotopes.

  18. Dielectronic recombination data for dynamic finite-density plasmas. VII. The neon isoelectronic sequence

    NASA Astrophysics Data System (ADS)

    Zatsarinny, O.; Gorczyca, T. W.; Korista, K.; Badnell, N. R.; Savin, D. W.

    2004-11-01

    Dielectronic recombination (DR) and radiative recombination (RR) data for neon-like ions forming sodium-like systems has been calculated as part of the assembly of a DR database necessary for modelling of dynamic and/or finite-density plasmas (Badnell et al. \\cite{Bad03}). Dielectronic recombination coefficients for neon-like ions from Na+ to Zn20+, as well as Kr26+, Mo32+, Cd38+, and Xe44+, are presented and the results discussed.

  19. ATP-dependent bioluminescence in the firefly squid, Watasenia scintillans.

    PubMed

    Tsuji, F I

    1985-07-01

    The Japanese firefly squid, Watasenia scintillans, emits intense flashes of light from three tiny luminous organs that are located at the tip of each of a pair of ventral arms. Light is also produced from hundreds of other minute organs that are scattered over the body. The luminescence is due to an ATP-dependent reaction, with an optimal pH of 8.80. The decay of light intensity follows first-order kinetics and the decay constant is independent of initial ATP concentration. The light emission also requires MgCl(2), a soluble component, and an insoluble component that is membrane bound. Squids represent a major group of organisms unrelated to fireflies in which ATP is required for bioluminescence. PMID:16593580

  20. ATP-dependent bioluminescence in the firefly squid, Watasenia scintillans

    PubMed Central

    Tsuji, Frederick I.

    1985-01-01

    The Japanese firefly squid, Watasenia scintillans, emits intense flashes of light from three tiny luminous organs that are located at the tip of each of a pair of ventral arms. Light is also produced from hundreds of other minute organs that are scattered over the body. The luminescence is due to an ATP-dependent reaction, with an optimal pH of 8.80. The decay of light intensity follows first-order kinetics and the decay constant is independent of initial ATP concentration. The light emission also requires MgCl2, a soluble component, and an insoluble component that is membrane bound. Squids represent a major group of organisms unrelated to fireflies in which ATP is required for bioluminescence. Images PMID:16593580

  1. High-speed operation of HTS SQUID-array interface circuits with a cryocooler

    Microsoft Academic Search

    Masahiro Horibe; Yoshinobu Tarutani; Keiichi Tanabe

    2004-01-01

    The authors evaluated the operation of high-temperature superconducting quantum interference device (SQUID)-array interface circuits (IFCs) with normal-metal control lines. Transimpedance amplification was obtained at an operating speed of 1 Gb\\/s using a cryocooler. The effect of the number of SQUIDs connected in series and the number of arrays connected in parallel on the level of output from the SQUID-array IFCs

  2. Development of a Neon Cryogenic Turbo-Expander with Magnetic Bearings

    NASA Astrophysics Data System (ADS)

    Hirai, H.; Hirokawa, M.; Yoshida, S.; Kamioka, Y.; Takaike, A.; Hayashi, H.; Okamoto, H.; Shiohara, Y.

    2010-04-01

    A cryogenic turbo-expander with active magnetic bearings was made and tested in a reverse-Brayton cycle refrigerator using neon as working fluid. Turbine isentropic efficiency is a very important factor for the refrigerator since it affects the performance of the refrigerator significantly. Properties of neon are suitable for the working fluid in a refrigerator to cool HTS (High Temperature Superconducting) applications. The neon refrigerator needs a very small and high speed turbo-expander. But there are few studies of isentropic efficiencies of cryogenic turbo-expander using neon gas. Thus the experiment to get the design information was carried out. A prototype of neon refrigerator was made for HTS applications in 2007. Its cooling power was 2 kW at temperature of 70 K and operated in process pressure between 2 MPa and 1 MPa. To improve the performance of the neon refrigerator, the process pressure was changed to 1 MPa˜0.5 MPa. Under this process pressure, isentropic efficiencies for two types of turbine impellers were obtained. The test results were included in to the turbine design program so that we could predict the isentropic efficiencies of the turbo-expander more accurately. Details of the turbo-expander design and test results are described in this report.

  3. A theoretical study on heat production in squid giant axon.

    PubMed

    Nogueira, R de A; Conde Garcia, E A

    1983-09-01

    The heat produced by action currents during the upstroke of the action potential in the squid axon has been calculated. Equations were developed and it was demonstrated that the phase plane area, obtained from nerve action potential upstroke, is a measure of the heat liberated at the axoplasmic level. Assuming the Hodgkin and Huxley model, it was possible to show that the axoplasmic heat is a constant fraction of the total Joule heating. PMID:6314059

  4. ATP-Dependent Bioluminescence in the Firefly Squid, Watasenia Scintillans

    Microsoft Academic Search

    Frederick I. Tsuji

    1985-01-01

    The Japanese firefly squid, Watasenia scintillans, emits intense flashes of light from three tiny luminous organs that are located at the tip of each of a pair of ventral arms. Light is also produced from hundreds of other minute organs that are scattered over the body. The luminescence is due to an ATP-dependent reaction, with an optimal pH of 8.80.

  5. Jumbo squid beaks: Inspiration for design of robust organic composites

    Microsoft Academic Search

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

    2007-01-01

    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

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

    Microsoft Academic Search

    Mingyan Yan; Bafang Li; Xue Zhao

    2009-01-01

    Collagen of squid (Ommastrephes bartrami) skin was examined in the present study. Histology showed that collagen fiber in the skin was partially cross-linked with\\u000a muscle fiber. Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were extracted from the skin and characterized.\\u000a The results of amino acid composition and electrophoretic patterns revealed that ASC and PSC were both type I collagen, containing

  7. Modeling and Simulation of a Microstrip-SQUID Amplifier

    E-print Network

    G. P. Berman; O. O. Chumak; D. I. Kamenev; D. Kinion; V. I. Tsifrinovich

    2011-09-23

    Using a simple lumped-circuit model, we numerically study the dependence of the voltage gain and noise on the amplifier's parameters. Linear, quasi-linear, and nonlinear regimes are studied. We have shown that the voltage gain of the amplifier cannot exceed a characteristic critical value, which decreases with the increase of the input power. We have also shown that the spectrum of the voltage gain depends significantly on the level of the Johnson noise generated by the SQUID resistors.

  8. Intracellular calcium buffering capacity in isolated squid axons

    Microsoft Academic Search

    F. J. BRINLEY; T. TIFFERT; A. SCARPA; L. J. MULLINS

    1977-01-01

    A B S TRA C T Changes in ionized calcium were studied in axons isolated from living squid by measuring absorbance of the Ca binding dye Arsenazo III using multiwavelength differential absorption spectroscopy. Absorption changes mea- sured in situ were calibrated in vitro with media of ionic composition similar to axoplasm containing CaEGTA buffers. Calcium loads of 50-2,500 \\/zmol\\/kg axo-

  9. Formation-flying interferometry

    Microsoft Academic Search

    Oliver P. Lay; Gary H. Blackwood

    2003-01-01

    There are many advantages to space-based interferometry, but monolithic, single-spacecraft platforms set limits on the collecting area and baseline length. These constraints can be overcome by distributing the optical elements of the interferometer over a system of multiple spacecraft flying in precise formation, opening up new realms of angular resolution and sensitivity. While the principles of interferometry are the same

  10. Go Fly a Kite

    ERIC Educational Resources Information Center

    Klopack, Ken

    2009-01-01

    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.)

  11. Fly on the Wall

    ERIC Educational Resources Information Center

    Berry, Dave; Korpan, Cynthia

    2009-01-01

    This paper describes the implementation of a peer observation program at the University of Victoria called the Lecture Club. The observers are not interactive during the class--they are the proverbial flies on the wall. The paper identifies the program as self-developmental, discussing the attributes of this learning-to-teach and peer-sharing…

  12. Statistical characterization of voltage-biased SQUIDs with weakly damped junctions

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    Recently, it has been shown that voltage-biased readout of SQUIDs with weakly damped junctions (large Stewart-McCumber parameter ?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.

  13. SQUID-based instrumentation for ultralow-field MRI

    NASA Astrophysics Data System (ADS)

    Zotev, Vadim S.; Matlashov, Andrei N.; Volegov, Petr L.; Urbaitis, Algis V.; Espy, Michelle A.; Kraus, Robert H., Jr.

    2007-11-01

    Magnetic resonance imaging at ultralow 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, a seven-channel SQUID system designed for simultaneous 3D ULF MRI and magnetoencephalography (MEG) is described. The system includes seven second-order SQUID gradiometers characterized by magnetic field resolutions of 1.2-2.8 fT Hz-1/2. It is also equipped with five sets of coils for 3D Fourier imaging with pre-polarization. Essential technical details of the design are discussed. The system's ULF MRI performance is demonstrated by multi-channel 3D images of a preserved sheep brain acquired at 46 µT measurement field with pre-polarization at 40 mT. The imaging resolution is 2.5 mm × 2.5 mm × 5 mm. The ULF MRI images are compared to images of the same brain acquired using conventional high-field MRI. Different ways to improve imaging SNR are discussed.

  14. SQUID array for magnetic inspection of prestressed concrete bridges

    NASA Astrophysics Data System (ADS)

    Krause, H.-J.; Wolf, W.; Glaas, W.; Zimmermann, E.; Faley, M. I.; Sawade, G.; Mattheus, R.; Neudert, G.; Gampe, U.; Krieger, J.

    2002-03-01

    For detection of tendon ruptures in prestressed members of bridges, a four-channel SQUID system was developed. The tendons are magnetized by scanning a yoke electromagnet over the concrete surface along the hidden member. Four HTS dc-SQUID magnetometers with ramp-type junctions, optimized for high-field performance, are mounted in an orientation-independent liquid nitrogen cryostat. The SQUIDs are integrated as a linear array within the yoke and operated in magnetic fields up to 15 mT, recording the stray field during magnetization as well as the remanent field after switching off the excitation. Unwanted signals from stirrups of the mild steel reinforcement are suppressed with two types of techniques: either the comparison of remanent field signals after changing the magnetization direction of the stirrups, or a best fit of typical stirrup signals to the stray field signal and their subtraction. Subsequent correlation analysis with the dipolar signal of a typical void yields rupture signal amplitudes. A finite element program was written to simulate stray field and remanent field traces of typical steel configurations. Excellent agreement with measured data was found. Results of measurements on a prestressed highway bridge are presented. Signal amplitudes above the threshold values were verified as originating from ruptures of the steel tendon by opening the bridge deck.

  15. Tunable Anomalous Supercurrent in a topological tri-junction SQUID

    NASA Astrophysics Data System (ADS)

    Kurter, C.; Finck, A. D. K.; Ghaemi, P.; Hor, Y. S.; van Harlingen, D. J.

    2014-03-01

    There has been intense interest in realizing Majorana fermions (MFs) in solid-state systems. Circuits of Josephson junctions (JJs) made of closely spaced s-wave superconductors on 3D topological insulators have been proposed to host zero energy Andreev bound states (ABSs) that act like MFs. Here, we present signatures of an anomalous supercurrent carried by topologically non-trivial low energy ABSs in a Nb/Bi2Se3/Nb tri-junction SQUID where two of the three superconducting leads are connected by a loop. An electrostatic top gate allows strong modulation of the supercurrent despite a high bulk contribution to the normal state conductance. In response to a magnetic field threading flux within the superconducting loop, we find unconventional SQUID oscillations enclosed by an envelope associated with a clear diffraction pattern, indicating spatially uniform and symmetric JJs. At a critical gate voltage, when the trivial 2DEG at the surface is nearly depleted, we observe a sharp drop in the critical current, signaling a topological phase transition in which the nature of the supercurrent-carrying states is transformed. This transition is accompanied by qualitative changes in the SQUID oscillations, magnetic diffraction pattern, and temperature dependence of the critical current. We acknowledge funding from Microsoft Station-Q.

  16. Parasitic effects in SQUID-based radiation comb generators

    E-print Network

    Riccardo Bosisio; Francesco Giazotto; Paolo Solinas

    2015-05-23

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

  17. A planar second-order DC SQUID gradiometer.

    PubMed

    Carelli, P; Chiaventi, L; Leoni, R; Pullano, M; Schirripa Spagnolo, G

    1991-01-01

    In this work we describe a DC SQUID gradiometer, sensitive to the second spatial derivative of the magnetic field. The sensitive area of the gradiometer is the inductive body of the DC SQUID itself. The isoflux line distribution generated by a dipolar source, obtained by performing magnetic measurements with an array of such detectors, is relatively complicated, but its localisation capability is similar to that one usually achieves with axial detector arrays. Planar gradiometers also show a better resolution for near sources and a stronger rejection of far disturbances. The final device is expected to have an inductance of a few hundreds of pH in order to obtain performances typical of a low noise DC SQUID. The pick-up coils will be the combination of four square holes of 500 microns side with a 1.05 cm baseline. Due to the magnetic field concentration (in the final device it can be a factor 10) the gradiometer will have a sensitivity of 10(-11) T m-2 Hz-1/2 and a field sensitivity of about 2 fT Hz-1/2. Some preliminary results, obtained on detectors with an intermediate area between the prototype and final device, are reported here. The process used to fabricate this second-order gradiometer is based on Nb-NbO chi-PbAuIn Josephson tunnel junctions. Some possible improvements will also be described. PMID:1807874

  18. Triple-Point Temperature and the Isotopic Composition of Three Commercial Neon Gases

    NASA Astrophysics Data System (ADS)

    Yang, I.; Gam, K. S.; Joung, W.; Kim, Y.-G.

    2015-04-01

    The triple-point temperature of neon, T_{tp-Ne} , is known to have dependence on the isotopic composition. Recently, the Technical Annex for the International Temperature Scale of 1990 was updated to specify the method of correction for the isotopic reference ratio of neon. In this study, to confirm this correction in the Technical Annex independently, the effects of the isotopic composition of neon on T_{tp-Ne} for three commercial neon gas sources were studied. For the measurement of the isotopic composition, a gas mass spectrometer was used to compare the sample gases with a reference neon gas whose isotopic composition was known with high precision by a gravimetric method. For the measurement of T_{tp-Ne} , an open-cell type cryostat for the realization of low-temperature fixed points was used. The physical cell and the thermal environment around it remained very similar for all T_{tp-Ne} measurements with the neon gases due to the nature of the open-cell type system. Therefore, the difference in T_{tp-Ne} among different samples could be measured with a relatively low uncertainty, canceling many systematic effects that are common to all measurements. Our result was consistent with the correction in the Technical Annex. Furthermore, because one of the commercial neon gases was the bottle that was used for KRISS measurements in the international comparison CCT-K2, it is now possible to correct the measurement for the reference isotopic ratio and compare it with other measurements for which isotopic composition data are available.

  19. Metal atom (Zn, Cd and Mg) luminescence in solid neon

    NASA Astrophysics Data System (ADS)

    Healy, Brendan; Kerins, Paul; McCaffrey, John G.

    2012-08-01

    Luminescence spectroscopy of the metal atoms Mg, Zn and Cd isolated in solid neon is recorded using pulsed synchrotron radiation excitation of the ns1np1 1P1-ns2 1S0 resonance (n = 3, 4 and 5 respectively) transitions. Two features, a dominant band and a red-shoulder, are identified in the UV absorption spectra of Zn/Ne and Cd/Ne. Excitation of these features yields distinct emission bands with the red-shoulder absorption producing the smaller, Stokes-shifted emission. Nanosecond decaytime measurements, made with the time correlated single photon counting technique indicate the emission bands arise from the spin singlet 1P1?1S0 transition. Hence, it is concluded that the duplication of absorption and emission features in the Cd/Ne and Zn/Ne systems arises from metal atom occupancy in two distinct sites. In contrast, Mg/Ne luminescence consists of single excitation and emission bands, indicative of occupancy in just one site. The occurrence of distinct photophysical characteristics of the linewidths, Stokes shift and lifetimes in the Mg/Ne system, compared with those recorded for Zn/Ne and Cd/Ne, is rationalized in terms of a different site occupancy for atomic Mg. Accurate interaction potentials for the ground states of the M . Ne diatomics are used to analyse site occupancies and interpret this contrasting behavior.

  20. Type Ia supernovae from exploding oxygen-neon white dwarfs

    E-print Network

    Marquardt, Kai S; Ruiter, Ashley J; Seitenzahl, Ivo R; Ohlmann, Sebastian T; Kromer, Markus; Pakmor, Ruediger; Roepke, Friedrich K

    2015-01-01

    The progenitor problem of Type Ia supernovae (SNe Ia) is still unsolved. Most of these events are thought to be explosions of carbon-oxygen (CO) white dwarfs (WDs), but for many of the explosion scenarios, particularly those involving the externally triggered detonation of a sub-Chandrasekhar mass WD (sub-M Ch WD), there is also a possibility of having an oxygen-neon (ONe) WD as progenitor. We simulate detonations of ONe WDs and calculate synthetic observables from these models. The results are compared with detonations in CO WDs of similar mass and observational data of SNe Ia. We perform hydrodynamic explosion simulations of detonations in initially hydrostatic ONe WDs for a range of masses below the Chandrasekhar mass (M Ch), followed by detailed nucleosynthetic postprocessing with a 384-isotope nuclear reaction network. The results are used to calculate synthetic spectra and light curves, which are then compared with observations of SNe Ia. We also perform binary evolution calculations to determine the nu...

  1. Effect of helium-neon laser on musculoskeletal trigger points

    SciTech Connect

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

    1986-07-01

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

  2. Neutrino oscillation signatures of oxygen-neon-magnesium supernovae

    SciTech Connect

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

    2008-07-15

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

  3. Neutrino oscillation signatures of oxygen-neon-magnesium supernovae

    E-print Network

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

    2008-06-16

    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.

  4. Helium and neon in lunar ilmenites of different antiquities

    NASA Technical Reports Server (NTRS)

    Nier, A. O.; Schlutter, D. J.

    1994-01-01

    Helium and neon were extracted from individual lunar ilmenite grains, approximately 100 micrometers in diameter, using a pulsed step-heating technique. Grains from lunar samples 71501 and 79035, believed to have been exposed to solar corpuscular radiation at greatly different times, were studied. The results found were consistent with the hypothesis that in addition to solar-wind-implanted gas, a second more deeply implanted component was present in both species of grains. Average isotopic ratios were determined giving equal weight to each of the particles. As found in depth studies employing chemical etching, both the He-3/He-4 and Ne-20/Ne-22 ratios were lower in the more deeply implanted gas than in the solar wind component. The He-3/He-4 ratio in the solar wind component of the more ancient grains was lower than that in the more recently exposed ones, whereas no difference was found for the more deeply embedded He. In the deeply embedded component of the ancient grains, the He-4/Ne-20 ratio was approx. 2x that found in the more recently exposed grains. In the shallowly implanted component, the ratio varied greatly from grain to grain, preventing comparison with the solar wind elemental composition.

  5. Biochemical changes associated with fast fermentation of squid processing by-products for low salt fish sauce

    Microsoft Academic Search

    Wei Xu; Gang Yu; Changhu Xue; Yong Xue; Yan Ren

    2008-01-01

    In order to enhance the economical values of squid processing by-products and reduce the environmental problems caused by the wastes from squid processing, the possibility of utilizing squid processing by-products for low salt fish sauce production was investigated. Low salt fish sauce was prepared experimentally from squid processing by-products, according to three different manufacturing techniques (A, B and C) with

  6. Origami Flying Disk

    NSDL National Science Digital Library

    Cy Tymony

    2011-01-01

    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.

  7. Noise sources and dissipation mechanisms of a 120 # SQUID amplifier Paolo Falferi, a) Michele Bonaldi, and Antonella Cavalleri

    E-print Network

    Noise sources and dissipation mechanisms of a 120 # SQUID amplifier Paolo Falferi, a) Michele device #SQUID#, based on a commercial sensor, is strongly coupled to an electrical resonator at 11 k of the noise generated by this system, the back action noise of the SQUID amplifier is estimated. The minimum

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

    E-print Network

    Benoit-Bird, Kelly J.

    Extreme plasticity in life-history strategy allows a migratory predator (jumbo squid) to cope (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically years. An El Ni~no event in 2009­2010, was accompanied by a collapse of this fishery, and squid

  9. BOHDAN M. SLABYJ, GORDON E. RAMSDELL, and RUTH H. TRUE Quality of Squid, II/ex illecebrosus,

    E-print Network

    BOHDAN M. SLABYJ, GORDON E. RAMSDELL, and RUTH H. TRUE Quality of Squid, II/ex illecebrosus, Mantles Canned in Oil Introduction Squid meat is equal to fish meat in protein content (16-20 percent). Compared with other marine ani- mals eaten by man, squid provide a relatively higher yield of edible parts

  10. Analysis of the Optimal Channel Density of the Squid Giant Axon Using a Reparameterized HodgkinHuxley Model

    E-print Network

    Levy, William B.

    Analysis of the Optimal Channel Density of the Squid Giant Axon Using a Reparameterized Hodgkin Friesen, and William B Levy. Analysis of the optimal channel density of the squid giant axon using optimal channel density is more than twice as high as the actual squid channel density. When the available

  11. Suppression of energy-relaxation-induced decoherence in -type three-level SQUID flux qubits: A dark-state approach

    E-print Network

    Chu, Shih-I

    Suppression of energy-relaxation-induced decoherence in -type three-level SQUID flux qubits: A dark level in the -type three-level SQUID flux qubits. We show that the energy-relaxation-induced decoherence quantum inter- ference device (SQUID), decoherence induced by energy re- laxation does not pose a serious

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

    E-print Network

    Romalis, Mike

    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

  13. Geographic, seasonal and ontogenetic variation in cadmium and mercury concentrations in squid (Cephalopoda: Teuthoidea) from UK waters

    E-print Network

    Paris-Sud XI, Université de

    1 Geographic, seasonal and ontogenetic variation in cadmium and mercury concentrations in squid (Todarodes sagittatus and Todaropsis eblanae) squid species collected from research cruise and fishery of the spawning season and in squid from the English Channel and the Scottish West Coast. It is likely

  14. Range Expansion of the Jumbo Squid in the NE Pacific: N Decrypts Multiple Origins, Migration and Habitat

    E-print Network

    Range Expansion of the Jumbo Squid in the NE Pacific: d15 N Decrypts Multiple Origins, Migration perturbations, the highly voracious jumbo squid Dosidicus gigas reached unprecedented northern latitudes along geographic origins that were initially detected by highly variable bulk d15 N values in gladii for squid

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

    E-print Network

    Boyer, Edmond

    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

  16. Environment, krill and squid in the Monterey Bay: from fisheries to life histories and backagain

    Microsoft Academic Search

    Teresa Isha; E. J. Dick; Paul V. Switzer; Marc Mangel

    The fishery for market squid in California is extremely valuable and only recently subject to regulations (in that sense, it is one of the last great open-access fisheries on the western coast of North America). We briefly review the history of the fishery for Loligo opalescens, on an annual time scale. Within-season analyses suggest that cohorts of squid persist offshore

  17. Compensation electronics for larger dynamic range of a SQUID based nondestructive evaluation system

    Microsoft Academic Search

    M. V. Kreutzbruck; A. Theiss; M. Mück; C. Heiden

    1999-01-01

    We have developed a compensation system for any given SQUID sensor which allows sensitive eddy current measurements above 100 Hz in the presence of strong and slowly varying background fields. High Tc SQUIDs have been used successfully in nondestructive evaluation (NDE) systems based on eddy current excitation when searching for defects in conductive samples such as aircraft parts. Due to

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  19. 77 FR 67305 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ...butterfish acceptable biological catch (ABC) to 4,200 mt (from 3,622 mt), and...current 2012 acceptable biological catch (ABC) for butterfish (3,622 mt) was too...longfin squid fishery derived from this ABC may close the longfin squid fishery...

  20. Confocal immunocytochemistry of embryonic and juvenile Hawaiian bobtail squid (Euprymna scolopes) tissues.

    PubMed

    Lee, Patricia N; McFall-Ngai, Margaret J; Callaerts, Patrick; de Couet, H Gert

    2009-11-01

    The Hawaiian bobtail squid Euprymna scolopes is a cephalopod whose small size, short lifespan, rapid growth, and year-round availability make it suitable as a model organism. This protocol describes the preparation of whole juvenile squids by whole-mount immunocytochemistry for visualization by confocal microscopy. PMID:20150059

  1. Current sensing noise thermometry using a low Tc DC SQUID preamplifier

    Microsoft Academic Search

    C. P. Lusher; Junyun Li; V. A. Maidanov; M. E. Digby; H. Dyball; A. Casey; J. Nyéki; V. V. Dmitriev; B. P. Cowan; J. Saunders

    2001-01-01

    We describe here the design and performance of a current sensing noise thermometer using a low Tc DC SQUID as the front end amplifier. The DC SQUID is used to measure the thermal noise current in a resistor and the temperature is then obtained from the Nyquist formula. The thermometer is fast, absolute and precise and is usable over a

  2. Scanning Electron Microscopy of Squid, Loligo peale;: Raw, Cooked, and Frozen Mantle

    E-print Network

    Scanning Electron Microscopy of Squid, Loligo peale;: Raw, Cooked, and Frozen Mantle W. STEVEN The main body portion of a squid is the cone-shaped mantle which encloses the viscera. Early studies description of the entire mantle structure as it relates · to locomotory function, and Moon and Hulbert (1975

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

    E-print Network

    Kier, William M.

    Ontogenetic Changes in Mantle Kinematics During Escape-Jet Locomotion in the Oval Squid investigated the kinematics of mantle movement during escape jet behavior in an ontogenetic series of Sepioteuthis lessoniana, the oval squid. Changes in mantle diameter during the jet were measured from digi

  4. Z-Gate Operation on a Superconducting Flux Qubit via Its Readout SQUID

    E-print Network

    Jin, X.?Y.

    Detuning a superconducting qubit from its rotating frame is one means to implement a Z-gate operation. In this work, we implement a Z gate by pulsing a current through the qubit’s readout dc SQUID. While the dc SQUID acts ...

  5. Control of the Electromagnetic Environment for Single Josephson Junctions Using Arrays of dc SQUIDs

    E-print Network

    Haviland, David

    Control of the Electromagnetic Environment for Single Josephson Junctions Using Arrays of dc SQUIDs-pair tunneling when the zero-bias resistance of the SQUID arrays is much higher than h/e2 26 k. I. INTRODUCTION The small-capacitance superconducting tunnel junction is a novel macroscopic quantum system [1],[2], which

  6. Pollution prevention and biochemical oxygen demand reduction in a squid processing facility

    Microsoft Academic Search

    Eugene Park; Richard Enander; Stanley M. Barnett; Chong Lee

    2001-01-01

    Fish processing, especially squid, creates high strength biochemical oxygen demand (BOD) wastewater that must be pretreated prior to sewer discharge. This study evaluated (1) new squid processing techniques, (2) advanced biological\\/chemical treatment technologies to meet local wastewater discharge regulations, and (3) recycling opportunities for materials formerly discarded as waste. Low technology modifications such as improved housekeeping\\/management systems were implemented in

  7. Pest Control on the "Fly"

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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.

  8. SQUID magnetometry from nanometer to centimeter length scales

    NASA Astrophysics Data System (ADS)

    Hatridge, Michael Jonathan

    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.

  9. Quantum entanglement of two flux qubits induced by an auxiliary SQUID

    E-print Network

    Shi, T

    2006-01-01

    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.

  10. Quantum entanglement of two flux qubits induced by an auxiliary SQUID

    E-print Network

    T. Shi; Z. Song

    2006-11-08

    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.

  11. Planar-type MgB2 SQUIDs utilizing a multilayer process

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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.

  12. Quantum analysis of a nonlinear microwave cavity-embedded dc SQUID displacement detector

    E-print Network

    P. D. Nation; M. P. Blencowe; E. Buks

    2008-06-25

    We carry out a quantum analysis of a dc SQUID mechanical displacement detector, comprising a SQUID with mechanically compliant loop segment, which is embedded in a microwave transmission line resonator. The SQUID is approximated as a nonlinear, current dependent inductance, inducing an external flux tunable, nonlinear Duffing self-interaction term in the microwave resonator mode equation. Motion of the compliant SQUID loop segment is transduced inductively through changes in the external flux threading SQUID loop, giving a ponderomotive, radiation pressure type coupling between the microwave and mechanical resonator modes. Expressions are derived for the detector signal response and noise, and it is found that a soft-spring Duffing self-interaction enables a closer approach to the displacement detection standard quantum limit, as well as cooling closer to the ground state.

  13. Stochastic resonance in an RF SQUID with shunted ScS junction

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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.

  14. NEON Data Products: Supporting the Validation of GCOS Essential Climate Variables

    NASA Astrophysics Data System (ADS)

    Petroy, S. B.; Fox, A. M.; Metzger, S.; Thorpe, A.; Meier, C. L.

    2014-12-01

    The National Ecological Observatory Network (NEON) is a continental-scale ecological observation platform designed to collect and disseminate data that contributes to understanding and forecasting the impacts of climate change, land use change, and invasive species on ecology. NEON will collect in-situ and airborne data over 60 sites across the US, including Alaska, Hawaii, and Puerto Rico. The NEON Biomass, Productivity, and Biogeochemistry protocols currently direct the collection of samples from distributed, gradient, and tower plots at each site, with sampling occurring either multiple times during the growing season, annually, or on three- or five-year centers (e.g. for coarse woody debris). These data are processed into a series of field-derived data products (e.g. Biogeochemistry, LAI, above ground Biomass, etc.), and when combined with the NEON airborne hyperspectral and LiDAR imagery, are used support validation efforts of algorithms for deriving vegetation characteristics from the airborne data. Sites are further characterized using airborne data combined with in-situ tower measurements, to create additional data products of interest to the GCOS community, such as Albedo and fPAR. Presented here are a summary of tower/field/airborne sampling and observation protocols and examples of provisional datasets collected at NEON sites that may be used to support the ongoing validation of GCOS Essential Climate Variables.

  15. Build a Fruit Fly Trap

    NSDL National Science Digital Library

    2011-08-20

    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.

  16. Pupil light reflex in the Atlantic brief squid, Lolliguncula brevis.

    PubMed

    McCormick, Lillian R; Cohen, Jonathan H

    2012-08-01

    Coleoid behavioral ecology is highly visual and requires an eye capable of forming images in a variety of photic conditions. A variable pupil aperture is one feature that contributes to this visual flexibility in most coleoids, although pupil responses have yet to be quantitatively documented for squid. The pupil light reflex (PLR) of the Atlantic brief squid, Lolliguncula brevis, was analyzed by directly exposing one eye of individual squid to light stimuli of varying irradiance and imaging the reflex, while simultaneously recording from the opposite, indirectly stimulated eye to determine whether the constriction was consensual between eyes. A PLR was measured in L. brevis, with an asymmetrical constriction observed under increasing irradiance levels that was not consensual between eyes, although a response of some level was observed in both eyes. Response thresholds ranged between 12.56 and 12.66 log photons cm(-2) s(-1). The PLR was rapid and dependent upon the stimulus irradiance, achieving half-maximum constriction within 0.49-1.2 s. The spectral responsivity of the PLR was analyzed by measuring the magnitude of the reflex in the eye directly stimulated by light of equal quantal intensity at wavelengths from 410 to 632 nm. The responsivity curve showed a maximum at 500 nm, indicating the eye is especially well suited for vision at twilight. These results, when considered in the context of the ambient light characteristics, show that the PLR of L. brevis contributes to a dynamic visual system capable of adjusting to the highly variable composition of light in its estuarine habitat. PMID:22786645

  17. Multiplexing of Hot-Electron Nanobolometers Using Microwave SQUIDs

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  18. Horse fly and Deer fly Control Phil Pellitteri, UW-Madison Insect Diagnostic Lab

    E-print Network

    Balser, Teri C.

    Horse fly and Deer fly Control Phil Pellitteri, UW-Madison Insect Diagnostic Lab There are over thirty species of blood feeding horse flies (Tabanus, Hybomitra) and deer flies (Chrysops) found until they get an opportunity to bite. Deer flies and horse flies can be active from May until September

  19. Dye-coupling in the early squid embryo

    Microsoft Academic Search

    Hans-Jürg Marthy; Brian Dale

    1989-01-01

    Functional cell-to-cell communicaton pathways were studied in pre-organogenetic squid embryos using the fluorescent dyes Lucifer Yellow-CH (LY) and Fluorescein-isothiocyanate Dextran (FITC-D). LY (M.Wt.450) micro-injected into ectoderm or mes-endoderm cells spread extensively over the embryo, flowing laterally along each germ layer, crossing germ layer boundaries and also the cell-to-yolk syncytium boundary. In contrast, when FITC-D (M.Wt.9000 or 17,500) was micro-injected into

  20. Optimum ion channel properties in the squid giant axon

    NASA Astrophysics Data System (ADS)

    Adair, Robert K.

    2004-04-01

    Evolutionary pressures are presumed to act so as to maximize the efficiency of biological systems. However, the utility of that premise is marred by the difficulties in defining and evaluating both the efficiency of systems and the character of the available variation space. Following Hodgkin and Adrian, we examine the character of voltage gated ion channels in the nonmyelinated giant axons of the squid and find that both the channel densities and channel transition rates have values that nearly optimize signal sensitivity as well as signal velocity.

  1. In a Tiny Squid, Bacterial Toxin Governs Organ Development

    NSDL National Science Digital Library

    EurekAlert!

    This EurekAlert! kids news article features information about the toxic molecule, tracheal cytotoxin, which is responsible for forming a light producing organ in the Bobtail squid-bacteria symbiosis. This toxin has been discovered to have both good and bad effects depending on the type of bacteria and host involved in the symbiosis: on one hand, it could cause disease and massive tissue damage, while on the other, it is vitally important in organ development. These recently discovered effects may force biologists to re-think the relationship between the world's many microorganisms and their host plants/animals.

  2. Resonance eigenstates of the SQUID-qubit system

    E-print Network

    Alec Maassen van den Brink

    2006-06-14

    We study the complex-valued resonance spectrum of a dc-SQUID coupled to a flux qubit, where the former is treated in the cubic and the latter in the two-level approximation. It is shown that this spectrum is well-defined and contains most of the relevant information on the escape process. Thus, the language of resonance states is precise and well-adapted to switching- (or trigger-) type qubit readout, and a worthwhile complement to the various descriptions of continuous qubit measurement. Initial progress is analytic, but nonperturbative numerical methods have been formulated and should soon yield accurate results for all parameter values.

  3. Synchronization of multiple coupled rf-SQUID flux qubits

    NASA Astrophysics Data System (ADS)

    Harris, R.; Brito, F.; Berkley, A. J.; Johansson, J.; Johnson, M. W.; Lanting, T.; Bunyk, P.; Ladizinsky, E.; Bumble, B.; Fung, A.; Kaul, A.; Kleinsasser, A.; Han, S.

    2009-12-01

    A practical strategy for synchronizing the properties of compound Josephson junction (CJJ) radio frequency monitored superconducting quantum interference device (rf-SQUID) qubits on a multi-qubit chip has been demonstrated. The impact of small (~1%) fabrication variations in qubit inductance and critical current can be minimized by the application of a custom-tuned flux offset to the CJJ structure of each qubit. This strategy allows for a simultaneous synchronization of the qubit persistent current and tunnel splitting over a range of external bias parameters that is relevant for the implementation of an adiabatic quantum processor.

  4. Studies of neutral ytterbium atoms in a solid neon matrix

    NASA Astrophysics Data System (ADS)

    Xu, Chenyu

    Ytterbium (Yb) atoms frozen in a solid neon (Ne) matrix qualitatively retain the structure of free atoms. Most of the Yb transitions are found to be blue-shifted in both absorption and emission spectra. Transitions also acquire significantly broadened linewidth, which can be a few nanometers for outer-shell transitions and as narrow as 0.03 nm (or 120 GHz) for inner-shell transitions. We explicitly demonstrate that the linewidth broadening is homogeneous for the 6s2 1S 0 - 6s6p 1 P1 transition. Splitting of transitions is observed as well, and is attributed to the broken spherical symmetry of the Yb trapping sites in solid Ne. The lifetimes of 6s6p 3 P0,1 in both 171Yb and 172Yb are measured in solid Ne using the spectrally-resolved fluorescence-decay technique. The finite vacuum lifetime of 6s6p 3P0 in 171Yb is due to the hyperfine quenching, and gives the natural linewidth of the Yb clock transition. With the measurements in solid Ne, we extract this vacuum lifetime for the first time after correcting for various medium effects. One effect is the index-of-refraction dependence of the spontaneous emission, of which we perform an independent calibration based on the 6s6p 3P1 lifetime in vacuum and in solid Ne. We obtain a vacuum decay rate of (4.42+/-0.35) x10--2 s--1for 6s6p 3P0 in 171Yb, which agrees with a recent calculation. The feasibility of optically polarizing 171Yb nuclei in solid Ne is discussed. The excitation rate of Yb transitions in solid Ne is suppressed by the same factor by which the absorption linewidth is broadened. The optical pumping efficiency for nuclear spins is estimated to be further suppressed by four orders of magnitude due to the presence of the crystal field.

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

    E-print Network

    Packard, Richard E.

    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

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

    Microsoft Academic Search

    W. Wang; X.-W. Liu

    2008-01-01

    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-

  7. New constraints on the HIMU mantle from neon and helium isotopic compositions of basalts from the CookAustral Islands

    E-print Network

    Mukhopadhyay, Sujoy

    New constraints on the HIMU mantle from neon and helium isotopic compositions of basalts from: helium neon isotopes HIMU mantle Cook­Austral Islands High 4 He/3 He ratios of 100000 to 160 000 found of recycled oceanic crust in the HIMU mantle source. However, significantly higher 4 He/3 He ratios

  8. NEON: the first continental-scale ecological observatory with airborne remote sensing of vegetation canopy biochemistry and structure

    Microsoft Academic Search

    Thomas U. Kampe; Brian R. Johnson; Michele Kuester; Michael Keller

    2010-01-01

    The National Ecological Observatory Network (NEON) is an ecological observation platform for discovering, understanding and forecasting the impacts of climate change, land use change, and invasive species on continental-scale ecology. NEON will operate for 30 years and gather long-term data on ecological response changes and on feedbacks with the geosphere, hydrosphere, and atmosphere. Local ecological measurements at sites distributed within

  9. Nova LMC (Large Magellanic Cloud) 1990 No. 1: The first extragalactic neon Nova

    SciTech Connect

    Sonneborn, G. (National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center Colorado Univ., Boulder, CO (USA). IUE Regional Data Analysis Facility); Shore, S.N. (Computer Sciences Corp., El Segundo, CA (USA) Colorado Univ., Boulder, CO (USA). IUE Regional Data Analysis Facility); Starrfield, S.G. (Arizona State Univ., Tempe, AZ (USA). Dept. of Physics and Astron

    1990-01-01

    IUE observations of Nova LMC 1990 No. 1, the first neon (or ONeMg) nova observed outside the Galaxy, were obtained from 17 January 1990 through March 1990, with especially dense coverage during the first 25 days of the outburst. (The neon'' nova categorization is based on the detection of forbidden Ne III-V lines in optical spectra; the ultraviolet neon lines were not detected.) During the first 30 days of the outburst, the radiative losses were dominated by the N V {lambda}1240 and C IV {lambda}1550 lines. The maximum ejection velocity was approximately 8000 km/s, based on the blue absorption edge of the C IV P-Cygni profile. Early in the outburst of Nova LMC 1990 No. 1 the UV luminosity alone was {approximately} 3 {times} 10{sup 38} erg/sec, implying that the bolometric luminosity was well in excess of the Eddington luminosity for a one solar mass object. 9 refs., 4 figs.

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

    PubMed

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

    2006-11-17

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

  11. 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.

  12. SQUID-Detected In Vivo MRI at Microtesla Magnetic Fields

    SciTech Connect

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

    2005-06-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

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

  14. Temperature characteristics of excitation in space-clamped squid axons.

    PubMed

    Guttman, R

    1966-05-01

    Temperature characteristics of excitability in the squid giant axon were measured for the space-clamped axon with the double sucrose gap technique. Threshold strength-duration curves were obtained for square wave current pulses from 10 microsec to 10 msec and at temperatures from 5 degrees C to 35 degrees C. The threshold change of potential, at which an action potential separated from a subthreshold response, averaged 17 mv at 20 degrees C with a Q(10) of 1.15. The average threshold current density at rheobase was 12 microa/cm(2) at 20 degrees C with a Q(10) of 2.35 compared to 2.3 obtained previously. At short times the threshold charge was 1.5.10(-8) coul/cm(2). This was relatively independent of temperature and occasionally showed a minimum in the temperature range. At intermediate times and all temperatures the threshold currents were less than for both the single time constant model and the two factor excitation process as developed by Hill. FitzHugh has made computer investigations of the effect of temperature on the excitation of the squid axon membrane as represented by the Hodgkin-Huxley equations. These are in general in good agreement with our experimental results. PMID:5961351

  15. SQUID-detected ultra-low field MRI

    NASA Astrophysics Data System (ADS)

    Espy, Michelle; Matlashov, Andrei; Volegov, Petr

    2013-03-01

    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.

  16. SQUID-detected ultra-low field MRI

    NASA Astrophysics Data System (ADS)

    Espy, Michelle; Matlashov, Andrei; Volegov, Petr

    2013-04-01

    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.

  17. SQUID-detected ultra-low field MRI.

    PubMed

    Espy, Michelle; Matlashov, Andrei; Volegov, Petr

    2013-04-01

    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. PMID:23452838

  18. SQUID-detected ultra-low field MRI.

    PubMed

    Espy, Michelle; Matlashov, Andrei; Volegov, Petr

    2013-03-01

    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 100mT) 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 >1T 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. PMID:23333456

  19. Neural control of tuneable skin iridescence in squid

    PubMed Central

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

    2012-01-01

    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

  20. Impact of SQUIDs on functional imaging in neuroscience

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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.

  1. Liquid neon heat transfer as applied to a 30 tesla cryomagnet

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    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.

  2. 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 ...

  3. The Flying University

    NASA Astrophysics Data System (ADS)

    Friesen, Catherine

    The Flying University is solo theater performance framed as an academic lecture about Marie Curie and her discovery of radium, delivered to a group of women who have gathered in secret to further their education. As the lecture proceeds, the professor brings in her own research based on a study of Esther Horsch (1905-1991) who lived on a farm in central Illinois. She introduces data from Esther's journals, personal memories, and dreams about Esther's life. The professor's investigation of radium plays at the intersections of magical and mundane, decay and the transformation of life, and the place of ambition in these two women's lives. The intention of this piece is to explore these themes, which are full of mystery, through the traces of the daily lives of Mme. Curie and Esther. Their words and photos are used as roots from which to imagine the things that echo beyond their familiar work; elemental and also fantastically radiant. The Flying University was written and performed by Catherine Friesen April 27-29, 2012 in the Center for Performance Experiment at Hamilton College as part of the University of South Carolina MFA Acting Class of 2013 showcase, Pieces of Eight.

  4. Development of an image processing system in splendid squid quality classification

    NASA Astrophysics Data System (ADS)

    Masunee, Niyada; Chaiprapat, Supapan; Waiyagan, Kriangkrai

    2013-07-01

    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.

  5. Auditory neuroscience in fruit flies.

    PubMed

    Kamikouchi, Azusa

    2013-07-01

    Since the first analysis of the Drosophila courtship song more than 50 years ago, the molecular and neural mechanisms underlying the acoustic communication between fruit flies has been studied extensively. The results of recent studies utilizing a wide array of genetic tools provide novel insights into the anatomic and functional characteristics of the auditory and other mechanosensory systems in the fruit fly. Johnston's hearing organ, the antennal ear of the fruit fly, serves as a complex sensor not only for near-field sound but also for gravity and wind. These auditory and non-auditory signals travel in parallel from the fly ear to the brain, feeding into neural pathways similar to the auditory and vestibular pathways of the human brain. This review discusses these recent findings and outlines auditory neuroscience in flies. PMID:23707240

  6. High-gain dc SQUID magnetometers with NbN nanobridges

    SciTech Connect

    Irie, A.; Hamasaki, K.; Yamashita, T. (Dept. of Electronics, Nagaoka Univ. of Technology, Kamitomioka-Machi 1603-1, Nagoka-shi, Niigata 940-21 (JP)); Matsui, T.; Komiyama, B. (Communication Research Lab., Ministry of Posts and Telecommunication, Koganei, Tokyo 184 (JP))

    1991-03-01

    This paper reports on high-gain dc SQUIDs using NbN nanobridges fabricated for magnetometers with high sensitivity, and their device parameters and intrinsic energy sensitivity have been evaluated. The slit inductance of the square washer SQUID was reduced by using the co-planar edge structure of the low inductance. The junction capacitance was typically 15 {approximately} 40 ft. The maximum voltage modualtion was about 110 {mu}V for the NbN nanobridge SQUID with an inductance of 0.18nH.

  7. Recombinant Globular Tail Fragment of Myosin-V Blocks Vesicle Transport in Squid Nerve Cell Extracts

    Microsoft Academic Search

    Jeremiah R. Brown; Kyle R. Simonetta; Leslie A. Sandberg; Phillip Stafford; George M. Langford

    Figure 1. (A) Western blot analyses of immunoprecipitation (IP) experiments using the GST-MyoV-tail. Clarified squid optic lobe homogenate was Triton X-100 extracted, incubated with the recombinant tail fragment fo r2ha t4°C, and recovered usinga-GST. (Lane 1) Squid myosin-V enriched fraction (S5B) probed with a-P196, a polyclonal squid myosin-V antibody (* denotes band of interest). (Lane 2) IP-GST-MyoV-tail probed with a-P196.

  8. Modlisation du SQUID rf en rflectomtrie : impdance la frquence de pompe, influence du bruit de fond

    E-print Network

    Paris-Sud XI, Université de

    1389 Modélisation du SQUID rf en réflectométrie : impédance à la fréquence de pompe, influence du, accepté le 29 juillet 1987) . Résumé. 2014 Les échanges d'énergie d'un circuit bouchon et d'un SQUID rf'abord précisée ; cette méthode, valide pour un SQUID largement hystérétique et faiblement couplé (k ~ 1) à un

  9. A SQUID readout system for a superconducting gyroscope. [superconducting quantum interference device

    NASA Technical Reports Server (NTRS)

    Hendricks, J. B.

    1975-01-01

    A design of a read out system for a superconducting gyroscope to be used in an orbiting gyroscope relativity experiment is discussed. The 'London Moment' of the superconducting rotor, which lies along the spin axis of the rotor, will be measured with a SQUID-type magnetometer. The SQUID will be built around the gyro rotor, with a very close spacing to give an inductance between 10 millionths and 1 millionth Hy. A SQUID of this design should resolve 2.07 times 10 to the minus 19th weber. The angular resolution of the gyroscope will then be 0.0035 arc-second, which is sufficient for the intended experiment.

  10. Flying radio frequency undulator

    SciTech Connect

    Kuzikov, S. V.; Vikharev, A. A. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod (Russian Federation)

    2014-07-21

    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.

  11. Spitzer finds cosmic neon's and sulfur's sweet spot: part III, NGC 6822

    Microsoft Academic Search

    R. H. Rubin; I. A. McNabb; J. P. Simpson; R. J. Dufour; A. W. A. Pauldrach; S. W. J. Colgan; T. W. Craven; E. D. Gitterman; C. C. Lo

    2010-01-01

    We observed several H ii regions in the dwarf irregular galaxy NGC 6822 using the infrared spectrograph on the Spitzer Space Telescope. Our aim is twofold: first, to examine the neon to sulfur abundance ratio in order to determine how much it may vary and whether or not, it is fairly `universal' second, to discriminate and test the predicted ionizing

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

    NASA Astrophysics Data System (ADS)

    Berukoff, S. J.

    2013-12-01

    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.

  13. Angular Dependence of the Scattering of Metastable Helium Atoms in Helium and Neon

    Microsoft Academic Search

    H. L. Richards; E. E. Muschlitz Jr.

    1964-01-01

    A molecular beam method has been used to perform scattering experiments with an atomic beam of metastable helium atoms in helium and neon. The atomic beam, in which some of the atoms had been excited by electron impact, was passed through a scattering chamber containing gas at low pressures and subsequently detected by electron ejection from gold surfaces. The 21S

  14. Polyvinyltoluene scintillators for relative ion dosimetry: an investigation with Helium, Carbon and Neon beams.

    E-print Network

    Boyer, Edmond

    and the relative dose. Keywords: Scintillation detectors, dosimetry, ion radiation effects, ion the beam or to monitor the dose during irradiation: ionisation chambers, nuclear tracks detectors with Helium, Carbon and Neon beams. David Broggio et al. 2 I. Introduction Different kinds of radiation

  15. Molecular simulation of the vapourliquid phase coexistence of neon and argon using ab initio potentials

    E-print Network

    -body interactions. For argon, simulations are compared with results obtained from NPH-ensemble molecular dynamics decades quantum chemistry was mainly used to calculate properties of single molecules. In the 1970sMolecular simulation of the vapour­liquid phase coexistence of neon and argon using ab initio

  16. Many-body and quantum effects in the radial distribution function of liquid neon and argon

    Microsoft Academic Search

    Elena Ermakova; Jan Solca; Hanspeter Huber; Dominik Marx

    1995-01-01

    Most simulations of liquids are performed in the framework of classical mechanics and the approximation of additivity of pair potentials. Besides errors due to the approximate pair potential, this leads to errors due to quantum effects and the neglect of many-body interactions. By calculating the radial distribution function from pure theory for liquid neon and argon with a quantum effective

  17. Helium, neon, and argon systematics of the European subcontinental mantle: Implications for its geochemical evolution

    Microsoft Academic Search

    T. J. Dunaim; H. Baur

    1995-01-01

    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

  18. Deep mantle neon and xenon preserve a record of early planetary differentiation and heterogeneous volatile accretion

    E-print Network

    Mukhopadhyay, Sujoy

    1 Deep mantle neon and xenon preserve a record of early planetary differentiation mantle outgassing and volatile loss from Earth1,2 . The low ratios of radiogenic to non-radiogenic xenon used as evidence for the existence of a relatively undegassed primitive deep mantle reservoir1

  19. A Magnus opus: Helium, neon, and argon isotopes in a North Sea oilfield

    Microsoft Academic Search

    C. J. Ballentine; M. L. Coleman

    1996-01-01

    This study of the Magnus oilfield, located in the East Shetland Basin, northern North Sea, represents the most detailed investigation of noble gas isotope systematics in a liquid hydrocarbon reservoir yet undertaken. Samples from nine producing wells across this Middle Jurassic field were taken and the helium, neon, and argon isotopic ratios and abundances in the oil were determined. Both

  20. Analysis of cold cathode glow neon discharges without anode glow or positive column †

    Microsoft Academic Search

    H. M. GRIMLEY; K. G. EMELEUS

    1971-01-01

    Plasma data given previously for the negative glow and Faraday dark space of near-normal cold cathode discharges in neon are supplemented by results, described briefly, for similar discharges without positive column or anode glow. The axial plasma electron concentration curves, which are sharply peaked near the cathode dark space when the cathode rays are strongly attenuated towards the anode, flatten

  1. The negative glow and Faraday dark space in near-normal neon discharges†

    Microsoft Academic Search

    G. A. WOOLSEY; R. M. REYNOLDS; W. B. MONTGOMERY; K. G. EMELEUS

    1969-01-01

    Radial and axial electrostatic probe measurements have been made of the negative glow and Faraday dark space of some weakly ‘ anomalous ’ cold cathode discharges in neon at pressures near 1 torr. These have been analysed and discussed with the aim of extending previous diffusion theories. Either an anode glow or positive column was present. The axial plasma electron

  2. LOW-ENERGY METASTABLE AUTOIONIZING STATES IN NITROGEN, OXYGEN, AND NEON (*)

    E-print Network

    Paris-Sud XI, Université de

    L-7 LOW-ENERGY METASTABLE AUTOIONIZING STATES IN NITROGEN, OXYGEN, AND NEON (*) K. O. GROENEVELD, G. Abstract. 2014 In the electron energy spectra used to determine life-times of the metastable three electron to the decay ofthe (Is 2s2) 2S1/2-state. The relatively long life-time ofthis non-metastable state may be due

  3. Neon: the UK Met office electro-optic tactical decision aid-current and future capability

    NASA Astrophysics Data System (ADS)

    Fox, S.; Wilson, D.; Lewis, W.

    2010-10-01

    The thermal contrast between two surfaces can vary dramatically with the atmospheric conditions. "Neon" is an application to predict the thermal contrast between different surfaces and their backgrounds, and the apparent contrast, given atmospheric conditions, when a target surface and background are viewed through a remotely situated infra-red camera. It is typically used in military assessments of how visible a target will be at a particular range. Recent research work to Neon has concentrated on the conversion of these apparent temperatures to more user-relevant descriptions of the detectability of the target. Accordingly, a development version of Neon now outputs "Detect", "Recognize" and "Identify" guidance. This paper briefly outlines the Neon concepts and then explores the methods behind the calculation of these detectability ranges and probabilities, and their comparison with a simple target acquisition range based only on the apparent contrast of the target and background. It finally explores how variations in the atmosphere impact upon the detectability of a target, and how the atmospheric impact will change with future improvements in sensor technology.

  4. Continental-Scale Stable Isotope Measurements at NEON to Address Ecological Processes Across Systems

    NASA Astrophysics Data System (ADS)

    Luo, H.; Goodman, K. J.; Hinckley, E. S.; West, J. B.; Williams, D. G.; Bowen, G. J.

    2013-12-01

    The National Ecological Observatory Network (NEON) is a national-scale research platform. The overarching goal of NEON is to enable understanding and forecasting of the impacts of climate change, land use change, and invasive species on aspects of continental-scale ecology (such as biodiversity, biogeochemistry, infectious diseases, ecohydrology, etc.). NEON focuses explicitly on questions that relate to grand challenges in environmental science, are relevant to large regions, and would otherwise be very difficult to address with traditional ecological approaches. The use of stable isotope approaches in ecological research has grown steadily during the last two decades. Stable isotopes at natural abundances in the environment trace and integrate the interaction between abiotic and biotic components across temporal and spatial scales. In this poster, we will present the NEON data products that incorporate stable isotope measurements in atmospheric, terrestrial, and aquatic ecosystems in North America. We further outline current questions in the natural sciences community and how these data products can be used to address continental-scale ecological questions, such as the ecological impacts of climate change, terrestrial-aquatic system linkages, land-atmosphere exchange, landscape ecohydrological processes, and linking biogeochemical cycles across systems. Specifically, we focus on the use of stable isotopes to evaluate water availability and residence times in terrestrial systems, as well as nutrient sources to terrestrial systems, and cycling across ecosystem boundaries.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  6. Molecular Studies of Fly-Borne Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vector-borne diseases are among the most significant threats to agriculture and human health. Mosquitoes are the most significant vectors of disease, but other biting and blood feeding flies such as black flies (Simuliidae), keds (Hippoboscidae), bot flies (Oestridae), and stable flies (Muscidae) a...

  7. SQUID-Detected Microtesla MRI in the presence of Metal

    SciTech Connect

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

    2006-09-06

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

  8. Thermal and Magnetic Responses of Spin Ice via SQUID Magnetometry

    NASA Astrophysics Data System (ADS)

    Schlax, K. W.; Moyer, J. A.; Thaler, A.; Sendgikoski, K.; MacDougall, G. J.; Schiffer, P.; van Harlingen, D. J.

    2015-03-01

    The spin ice pyrochlore class of frustrated magnets exhibits quasiparticle excitations that behave like Dirac monopoles on the pyrochlore lattice. We are studying single crystals of the spin ice Dy2Ti2O7 using dc SQUID magnetometry to look for thermal fluctuations in the monopole density. Specifically, we are seeking to observe a local excess of monopole magnetic charge induced by the simultaneous application of a temperature gradient, which should create a gradient in the monopole density, and a parallel magnetic field, which drives the flow and counterflow of oppositely-charged monopoles. This configuration should allow us to investigate the distribution, dynamics, and relaxation of the monopole-like excitations in spin ice pyrochlores. Work supported by the National Science Foundation under Grant DMR-1341793.

  9. A Spatially-Ordered Pacemaker Observed in Squid Giant Axons

    NASA Astrophysics Data System (ADS)

    Matsumoto, Gen; Aihara, Kazuyuki; Utsunomiya, Toshio

    1982-03-01

    It was both theoretically and experimentally demonstrated that a spatially-ordered pacemaker generating action potentials at a constant rhythm was formed at a restricted region on the squid giant axon in the state of self-sustained oscillation of the action potentials. The dynamics of the Hodgkin-Huxley equations with one-dimensional diffusion were analysed to study the spatially-ordered pacemaker under the following conditions; (1) the rate constants of sodium activation and inactivation, and potassium activation changed with the effective calcium concentration in the external medium, according to Frankenhaeuser and Hodgkin (J. Physiol. 137 (1957) 218), and (2) the membrane potentials at both ends of the axon were fixed to be zero. These experiments and calculation show that the repetitive firing state is spatially well organized and integrated, and that it could be called as the dissipative structure of Glansdorff and Prigogine macroscopically

  10. Optimization of the leak conductance in the squid giant axon

    NASA Astrophysics Data System (ADS)

    Seely, Jeffrey; Crotty, Patrick

    2010-08-01

    We report on a theoretical study showing that the leak conductance density, GL , in the squid giant axon appears to be optimal for the action potential firing frequency. More precisely, the standard assumption that the leak current is composed of chloride ions leads to the result that the experimental value for GL is very close to the optimal value in the Hodgkin-Huxley model, which minimizes the absolute refractory period of the action potential, thereby maximizing the maximum firing frequency under stimulation by sharp, brief input current spikes to one end of the axon. The measured value of GL also appears to be close to optimal for the frequency of repetitive firing caused by a constant current input to one end of the axon, especially when temperature variations are taken into account. If, by contrast, the leak current is assumed to be composed of separate voltage-independent sodium and potassium currents, then these optimizations are not observed.

  11. Global bifurcation structure in periodically stimulated giant axons of squid

    NASA Astrophysics Data System (ADS)

    Takahashi, Nobuyuki; Hanyu, Yoshiro; Musha, Toshimitsu; Kubo, Ryogo; Matsumoto, Gen

    1990-07-01

    The responses of a squid giant axon fell into three categories; phase-locked, quasi-periodic and chaotic. A bifurcation structure of the response patterns was obtained as a function parameters, I/ It (the current pulse intensity) normalized by threshold current) and T (current pulse intervals). The periodic responses appeared through either tangent bifurcation or type III bifurcation, parameters of I/ It and T. The characteristics of the response patterns and the bifurcation structure could be qualitatively explained by considering the two effects of periodic current input on normal axons; one is to act as a periodic external force and the other is to induce self-oscillation in the axon. Both the response and bifurcation characteristics could be ascribed to a specific nonlinear interaction between the induced self-oscillation and the periodic input.

  12. Multimodal transition and stochastic antiresonance in squid giant axons.

    PubMed

    Borkowski, L S

    2010-10-01

    The experimental data of Takahashi [Physica D 43, 318 (1990)], on the response of squid giant axons stimulated by periodic sequence of short current pulses is interpreted within the Hodgkin-Huxley model. The minimum of the firing rate as a function of the stimulus amplitude I0 in the high-frequency regime is due to the multimodal transition. Below this singular point only odd multiples of the driving period remain and the system is sensitive to noise. The coefficient of variation has a maximum and the firing rate has a minimum as a function of the noise intensity, which is an indication of the stochastic coherence antiresonance. The model calculations reproduce the frequency of occurrence of the most common modes in the vicinity of the transition. A linear relation of output frequency vs I0 above the transition is also confirmed. PMID:21230315

  13. The embryonic development of the Hawaiian bobtail squid (Euprymna scolopes).

    PubMed

    Lee, Patricia N; Callaerts, Patrick; de Couet, H Gert

    2009-11-01

    A staging series based on easily distinguishable morphological features is a basic and necessary tool for developmental studies. It provides a consistent reference for comparisons between independent studies, negates the need to know when fertilization occurred, allows correlation of the phase of development with the time of development (to facilitate collection of embryos at specific stages), and allows comparisons between species. Given the growing interest in Hawaiian bobtail squid (Euprymna scolopes) as a contemporary cephalopod developmental system, this article provides a detailed survey of E. scolopes embryogenesis from cleavage through hatching under controlled environmental conditions, including detailed descriptions of externally visible morphological features that are easily distinguished in either live or freshly fixed embryos under a dissecting microscope. Photomicrographs are also provided to aid in the accurate and rapid staging of E. scolopes embryos. PMID:20150049

  14. Cell junctions in early embryos of squid (Loligo pealei).

    PubMed

    Ginzberg, R D; Morales, E A; Spray, D C; Bennett, M V

    1985-01-01

    Squid embryos examined by freeze-fracture and thin-section electron microscopy exhibit identifiable gap junctions during mid-cleavage stages (stages 7-8), and junctional complexes composed of adherent appositions, elaborate septate junctions and gap junctions at slightly later stages (stages 12-13). During germinal layer establishment (stages 12-13) cytoplasmic bridges frequently link the embryonic cells. The presence of gap junctions in cleavage-stage embryos provides the morphological substrate for a demonstrated pathway of direct cell-cell communication that is modifiable by experimental treatments and may be physiologically regulatable. The existence of septate junctions and adherent contacts at later stages suggests that some functional specialization, perhaps the establishment of a strongly joined framework of cells at the surface of the embryo, accompanies the formation of germinal layers. PMID:3986876

  15. Multichannel DC SQUID sensor array for biomagnetic applications

    SciTech Connect

    Hoenig, H.E.; Daalmans, G.M.; Bar, L.; Bommel, F.; Paulus, A.; Uhl, D.; Weisse, H.J. (Siemens Corp. Research, P.O. Box 3220, D8520 Eriangen (DE)); Schneider, S.; Seifert, H.; Reichenberger, H.; Abraham-Fuchs, K. (Siemens Medical Engineering Group, D8520 Eriangen (DE))

    1991-03-01

    This paper reports on a biomagnetic multichannel system for medical diagnosis of brain and heart KRENIKON has been developed. 37 axial 2st order gradiometers - manufactured as flexible superconducting printed circuits - are arranged in a circular flat array of 19 cm diameter. Additionally, 3 orthogonal magnetometers are provided. The DC SQUIDs are fabricated in all-Nb technology, ten on a chip. The sensor system is operated in a shielded room with two layers of soft magnetic material and one layer of Al. The every day noise level is 10 fT/Hz{sup 1/2} at frequencies above 10 Hz. Within 2 years of operation in a normal urban surrounding, useful clinical applications have been demonstrated (e.g. for epilepsy and heart arrhythmias).

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

  17. Image processing of scanning SQUID microscope for observing superconducting nanostructures

    NASA Astrophysics Data System (ADS)

    Hayashi, Masahiko; Thanh Huy, Ho; Ishida, Takekazu

    2012-02-01

    A newly developed image processing technique for the scanning superconducting quantum interference device (SQUID) microscope is presented and its application to several measurements on superconducting nanostructures, including networks and dots, is discussed. This method is based on the detailed analysis of the structures characteristic to the measurement apparatus, such as the shape and position of the pickup coil. We take account of the Meissner effect in the coil body and its influences on the obtained image are carefully removed. The separation between the coil and the sample is also considered. Actually applying this method, we present images of the superconducting networks and dots, which show clear improvement from the raw images. The results are also discussed from physical point of view.

  18. Subtropical Fruit Fly Invasions into Temperate Fruit Fly Territory in California's San Joaquin Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subtropical fruit fly species including peach fruit fly, Bactrocera zonata (Saunders); melon fly, B. cucurbitae (Coquillett); oriental fruit fly, B. dorsalis (Hendel); and Mediterranean fruit fly, Ceratitis capitata Weidemann, have been detected in the past decade in the San Joaquin Valley of Califo...

  19. Features governing symbiont persistence in the squid-vibrio association.

    PubMed

    Koch, Eric J; Miyashiro, Tim; McFall-Ngai, Margaret J; Ruby, Edward G

    2014-03-01

    Experimental studies of the interaction between host and symbiont in a maturing symbiotic organ have presented a challenge for most animal-bacterial associations. Advances in the rearing of the host squid Euprymna scolopes have enabled us to explore the relationship between a defect in symbiont light production and late-stage development (e.g. symbiont persistence and tissue morphogenesis) by experimental colonization with specific strains of the symbiont Vibrio fischeri. During the first 4 weeks postinoculation of juvenile squid, the population of wild-type V. fischeri increased 100-fold; in contrast, a strain defective in light production (?lux) colonized normally the first day, but exhibited an exponential decline to undetectable levels over subsequent weeks. Co-colonization of organs by both strains affected neither the trajectory of colonization by wild type nor the decline of ?lux levels. Uninfected animals retained the ability to be colonized for at least 2 weeks posthatch. However, once colonized by the wild-type strain for 5 days, a subsequent experimentally induced loss of the symbionts could not be followed by a successful recolonization, indicating the host's entry into a refractory state. However, animals colonized by the ?lux before the loss of their symbionts were receptive to recolonization. Analyses of animals colonized with either a wild-type or a ?lux strain revealed slight, if any, differences in the developmental regression of the ciliated light-organ tissues that facilitate the colonization process. Thus, some other feature(s) of the ?lux strain's defect also may be responsible for its inability to persist, and its failure to induce a refractory state in the host. PMID:24118200

  20. The Form and Dimensions of the Giant Synapse of Squids

    NASA Astrophysics Data System (ADS)

    Martin, R.; Miledi, R.

    1986-03-01

    A study was made of the distal giant synapse, and of proximal synapses, in the stellate ganglion of the squid, Loligo vulgaris. For this purpose we injected iontophoretically dyes or cobalt ions into the pre- or postsynaptic axon. The intra-axonal movement of visible dyes was measured. Both presynaptic fibres, the main second order giant axon and the largest accessory axon, branched to make multiple synaptic contacts on the giant motor axons from near the perikarya down to near the exit of the stellar nerves from the ganglion. There were considerable individual variations in the branching patterns of the presynaptic giant axon and in the course and number of the postsynaptic giant axons. More than one accessory axon made contact with the largest motor axon. Fine structural details of the synapse are presented. The size of the contact area made by the main presynaptic axon on the last postsynaptic axon of a medium-sized animal was estimated from low power electron micrographs. We measured and counted synaptic contacts, synaptic vesicles and mitochondria. The fine structure of proximal synapses was found to be very similar to that of the distal synapse. Cobalt- or dye-injected ganglia showed that the perikarya of the axons which fuse to form the postsynaptic giant axons are located in diffuse and overlapping areas of the giant fibre lobe. In freshly hatched larvae the giant synapse was well differentiated; a gradient of differentiation from brain to periphery was detectable. The distal giant synapses of the oegopsid squid Todarodes sagittatus and of Sepia officinalis differed from the Loligo synapse. In Todarodes and Sepia collaterals and processes from both the presynaptic and the postsynaptic giant fibres are shown to meet in numerous contacts in the enlarged sheath surrounding the third order axon. In several respects the Loligo giant fibre system appears to represent in phylogenetical order the more evolved neuronal network.

  1. Features governing symbiont persistence in the squid-vibrio association

    PubMed Central

    Koch, Eric J.; Miyashiro, Tim; McFall-Ngai, Margaret J.; Ruby, Edward G.

    2013-01-01

    Experimental studies of the interaction between host and symbiont in a maturing symbiotic organ have presented a challenge for most animal-bacterial associations. Advances in the rearing of the host squid Euprymna scolopes have enabled us to explore the relationship between a defect in symbiont light production and late-stage development (e.g., symbiont persistence and tissue morphogenesis) by experimental colonization with specific strains of the symbiont Vibrio fischeri. During the first four weeks post-inoculation of juvenile squid, the population of wild-type V. fischeri increased 100-fold; in contrast, a strain defective in light production (?lux) colonized normally the first day, but exhibited an exponential decline to undetectable levels over subsequent weeks. Co-colonization of organs by both strains affected neither the trajectory of colonization by wild type, nor the decline of ?lux levels. Uninfected animals retained the ability to be colonized for at least two weeks post-hatch. However, once colonized by the wild-type strain for 5 days, a subsequent experimentally induced loss of the symbionts could not be followed by a successful recolonization, indicating the host’s entry into a refractory state. However, animals colonized by the ?lux before the loss of their symbionts were receptive to recolonization. Analyses of animals colonized with either a wild-type or a ?lux strain revealed slight, if any, differences in the developmental regression of the ciliated light-organ tissues that facilitate the colonization process. Thus, some other feature(s) of the ?lux strain’s defect also may be responsible for its inability to persist, and its failure to induce a refractory state in the host. PMID:24118200

  2. Aquatic Biogeochemical Prototype Activities at the National Ecological Observatory Network (NEON)

    NASA Astrophysics Data System (ADS)

    Goodman, K. J.; Powell, H.; Cilke, T.; Price, A.

    2010-12-01

    NEON is currently prototyping select data collections in order to develop robust protocols and procedures to be used across a gradient of stream systems, evaluating morphological mapping tools, and designing lightweight equipment and secure, stable, non-intrusive sensor installations. Here we present the status of the Aquatic prototype efforts that are occurring at the D15 Candidate Core Aquatic site: Red Butte Creek, Utah. Prototype activities include discharge and reaeration measurements, development of a stream reaeration rating curve, and water chemistry sampling. We are measuring reaeration, a measure of gas exchange across the air-water interface, using a continuous injection of SF6, an inert gas. In addition, Cl-, a conservative tracer, is added to the stream to account for dilution by groundwater inputs. As part of the NEON Prototype effort, we re-designed a lightweight, easy-to- use pump system for the addition of this conservative tracer during reaeration measurements. This pump, which costs a fraction of commercially available pumps, has performed well during field-testing and meets NEON’s needs and requirements for the injection of the conservative tracer. The NEON prototype efforts will help ensure that the data collected across the Observatory, including the 36 aquatic sites across 19 ecoclimatic domains, will enable researchers to investigate and model ecosystems response to climate change and landuse change at multiple spatial and temporal scales. The Observatory will collect data from both in-situ sensors and field data collections to produce measurements using consistent and standardized procedures and protocols across the United States. During Observatory Operations, these data will be available to the public on the web in near-real time.

  3. NEON: High Frequency Monitoring Network for Watershed-Scale Processes and Aquatic Ecology

    NASA Astrophysics Data System (ADS)

    Vance, J. M.; Fitzgerald, M.; Parker, S. M.; Roehm, C. L.; Goodman, K. J.; Bohall, C.; Utz, R.

    2014-12-01

    Networked high frequency hydrologic and water quality measurements needed to investigate physical and biogeochemical processes at the watershed scale and create robust models are limited and lacking standardization. Determining the drivers and mechanisms of ecological changes in aquatic systems in response to natural and anthropogenic pressures is challenging due to the large amounts of terrestrial, aquatic, atmospheric, biological, chemical, and physical data it requires at varied spatiotemporal scales. The National Ecological Observatory Network (NEON) is a continental-scale infrastructure project designed to provide data to address the impacts of climate change, land-use, and invasive species on ecosystem structure and function. Using a combination of standardized continuous in situ measurements and observational sampling, the NEON Aquatic array will produce over 200 data products across its spatially-distributed field sites for 30 years to facilitate spatiotemporal analysis of the drivers of ecosystem change. Three NEON sites in Alabama were chosen to address linkages between watershed-scale processes and ecosystem changes along an eco-hydrological gradient within the Tombigbee River Basin. The NEON Aquatic design, once deployed, will include continuous measurements of surface water physical, chemical, and biological parameters, groundwater level, temperature and conductivity and local meteorology. Observational sampling will include bathymetry, water chemistry and isotopes, and a suite of organismal sampling from microbes to macroinvertebrates to vertebrates. NEON deployed a buoy to measure the temperature profile of the Black Warrior River from July - November, 2013 to determine the spatiotemporal variability across the water column from a daily to seasonal scale. In July 2014 a series of water quality profiles were performed to assess the contribution of physical and biogeochemical drivers over a diurnal cycle. Additional river transects were performed across our site reach to capture the spatial variability of surface water parameters. Our preliminary data show differing response times to precipitation events and diurnal processes informing our infrastructure designs and sampling protocols aimed at providing data to address the eco-hydrological gradient.

  4. Taming the SQUID: How a nuclear physics education (mostly) helped my career in applied physics

    NASA Astrophysics Data System (ADS)

    Espy, Michelle

    2013-10-01

    My degree is in experimental nuclear physics, specifically studying the interaction of pions with nuclei. But after graduation I accepted a post-doctoral research position with a team based on applications of the Superconducting Quantum Interference Device (SQUID) to the study of the human brain. Despite knowing nothing about the brain or SQUIDs to start with, I have gone on to enjoy a career in applications of the SQUID and other sensors to the detection of weak magnetic fields in a variety of problems from brain studies (magnetoencephalography) to ultra-low field nuclear magnetic resonance for detection of explosives and illicit material. In this talk I will present some background on SQUIDs and their application to the detection of ultra-weak magnetic fields of biological and non-biological origin. I will also provide a little insight into what it has been like to use a nuclear physics background to pursue other types of science.

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

    E-print Network

    McFall-Ngai, Margaret

    Differential gene expression in bacterial symbionts from loliginid squids demonstrates variation to the colonization process. Therefore, we identified bacterial genes required for successful colonization-living stages. Selective capture of transcribed sequences (SCOTS) was used to differentiate genes expressed

  6. Bi-SQUIDs with submicron cross-type Josephson tunnel junctions

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    We present and discuss results for the experimental evaluation of bi-SQUIDs with shunted submicron cross-type Josephson tunnel junctions characterized by low capacitance. Such a technology, meant for SQUID sensors, was developed to enable unshielded operation of the sensors and to avoid unwanted flux trapping. The obtained voltage response swing is as high as 60 µV. The observed differences between the measured and theoretically predicted voltage responses are analyzed and the possible ways to approach a triangular voltage response shape are discussed. An improved design of such bi-SQUIDs with gradiometric topology is suggested to compensate for the influence of the sizable parasitic three-junction loop, which is the main drawback of the implemented bi-SQUID topology.

  7. Non-linear dynamics, entanglement and the quantum-classical crossover of two coupled SQUID rings

    E-print Network

    M. J. Everitt

    2009-09-24

    We explore the quantum-classical crossover of two coupled, identical, superconducting quantum interference device (SQUID) rings. We note that the motivation for this work is based on a study of a similar system comprising two coupled Duffing oscillators. In that work we showed that the entanglement characteristics of chaotic and periodic (entrained) solutions differed significantly and that in the classical limit entanglement was preserved only in the chaotic-like solutions. However, Duffing oscillators are a highly idealised toy model. Motivated by a wish to explore more experimentally realisable systems we now extend our work to an analysis of two coupled SQUID rings. We observe some differences in behaviour between the system that is based on SQUID rings rather than on Duffing oscillators. However, we show that the two systems share a common feature. That is, even when the SQUID ring's trajectories appear to follow (semi) classical orbits entanglement persists.

  8. 77 FR 74159 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ...NMFS proposes changing the butterfish mortality cap on the longfin squid fishery from...also proposes reducing the butterfish mortality cap for the 2013 fishing year by 13 percent...previously included in the butterfish mortality cap allocation. The adjustment...

  9. Observation of cascaded two-photon-induced transitions between fluxoid states of a SQUID

    E-print Network

    Han, Siyuan; Lukens, J. E.; Rouse, R.

    2000-02-07

    We present evidence for transitions between fluxoid wells of a SQUID due to cascaded, two-photon processes. Such transitions are evidenced by an anomalous dependence on the transition rate from the one-photon resonant level ...

  10. New NMR well logging/fracture mapping technique with possible application of SQUID NMR detection

    SciTech Connect

    Jackson, J.A.

    1981-01-01

    A new method for making NMR measurements has been developed that potentially can receive NMR signals from a precise distance into the geologic formation. It is based on the production of a toroidal region of homogeneous radial magnetic field near the mid-plane between two magnets arranged axially so their fields oppose between them. NMR signals have been detected from such a region in the laboratory. Preliminary data have been extrapolated to the projected performance of a logging tool using superconducting magnets. The presence of cryogenic temperatures required for these magnets may make signal detection using SQUIDs a logical consideration. Preliminary comparison of normal and SQUID NMR detection shows that near the borehole (<18 in.) standard NMR detection is probably superior; at greater distances SQUID detection may be advantageous. Directional detection of the signal may allow fractures near the wellbore to be mapped. Use of SQUID detection may be useful for this application.

  11. Solar wind helium, neon, and argon in Genesis aluminum collectors

    NASA Astrophysics Data System (ADS)

    Mabry, Jennifer Christine

    2009-11-01

    The Sun contains over 99% of the mass of the solar system and so, to fully develop a model of how the solar system formed and evolved what the starting composition was and how it evolved, it is crucial to know the isotopic composition of the sun. The Genesis mission collected samples of solar wind (SW) for 853 days and returned them to Earth for analysis. Making these measurements on earth-based instruments is currently the only way to get sufficient precision to differentiate between different solar system components, and SW is the only source of solar material available for sampling. However, there are several processes that have the potential to significantly alter the composition between the time when SW ions are accelerated away from the sun, to the time the laboratory measurements are made. This work attempts to constrain these sources of fractionation and present the best estimate of the isotopic composition of SW helium, neon, and argon implanted into two different aluminum SW collectors on board the Genesis Mission, Al on sapphire and polished Al. First, during the collection phase of the Genesis mission, diffusion can alter the initial implantation profiles of the SW ions in the collector targets and cause losses of shallowly implanted species. These losses preferentially affect the lighter isotopes, which in turn means the measured ratios of the remaining reservoir will be heavier, both isotopically and elementally. I have conducted a diffusion experiment on a similar time scale as the Genesis mission to determine the diffusion parameters of the two different aluminum collector materials and to quantify the changes in the measured ratios due to diffusive losses for the light noble gases. The results of this experiment show that the polished Al collector is not sufficiently retentive of the light noble gases to be a reliable collector for the light gases, but that the composition of the light gases implanted in the Al on sapphire collector does not show a measurable effect due to thermal diffusion. Isotopic fractionation can also occur even before implantation of the SW ions, if the processes which accelerate the SW away from the sun are mass-dependent. In an effort to quantify this effect, the Genesis mission collected separate samples of different types ('regimes') of SW: low-speed, high-speed, and coronal mass ejections, in addition to collecting bulk SW. Compositional differences between the different SW regimes (especially the low-speed and high-speed SW) are thought to provide a measure of this fractionation. By making high-precision isotopic measurements on collectors of the three SW regimes, we have put strict upper limits on the difference between the low- speed and high-speed SW regimes: 20 Ne/ 22 Ne < 0.24 ± 0.37% and 36 Ar/ 38 Ar < 0.11 ± 0.26%. Both of these differences are less than 1s statistical errors. Helium isotopes are much more susceptible to modification which prevents us from putting a strict upper limit as for Ne and Ar. And finally we have made isotopic measurements of the light noble gases of the bulk SW (without selective collection of different SW regimes) from the aluminum collectors. Accounting for the sources of fractionation discussed above, I propose the following as the best current bulk SW isotopic values: 20 Ne/ 22 Ne = 13.75 ± 0.02, 21 Ne/ 22 Ne = 0.0329 ± 0.0002, and 36 Ar / 38 Ar = 5.501 ± 0.005 (all errors are 1s).

  12. Development of a Low-Noise SQUID-Based Microtesla MRI System

    Microsoft Academic Search

    Whittier Myers; Michael Mößle; Seungkyun Lee; Nathan Keslo; Alexander Pines; John Clarke

    2004-01-01

    It has been recently demonstrated that ultra-low field magnetic resonance imaging (MRI) using an untuned Superconducting QUantum Intereference Device (SQUID) detector can produce 1-mm resolution images. The protons in the sample were prepolarized in a 0.3 T field, manipulated by ˜100 muT\\/m gradient fields for image encoding, and detected by the SQUID in the 130 muT measurement field. To reduce

  13. Noise characterization of highly sensitive SQUID magnetometer systems in unshielded environments

    NASA Astrophysics Data System (ADS)

    Chwala, A.; Kingman, J.; Stolz, R.; Schmelz, M.; Zakosarenko, V.; Linzen, S.; Bauer, F.; Starkloff, M.; Meyer, M.; Meyer, H.-G.

    2013-03-01

    To measure the noise performance of highly sensitive SQUID magnetometer systems directly is nearly impossible due to superimposed external noise. In magnetically unshielded environments in particular one needs sophisticated methods in order to get an estimate of the intrinsic noise. We compare different approaches to estimate the noise of our latest SQUID magnetometer systems in the Earth’s magnetic field and compare the results with measurements in magnetic (and superconductive) shielding.

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

    PubMed Central

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  16. Interactive Fly: Germ Band Extension

    NSDL National Science Digital Library

    PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

    2006-12-12

    In situ images from an award-winning and comprehensive site, The Interactive Fly. Entering through an expression pattern, this site thoroughly discusses each genes and shows its expression relative to other genes at this stage.

  17. Interactive Fly: CNS Expression Images

    NSDL National Science Digital Library

    PhD Thomas B Brody (NIH Laboratory of Neurochemistry)

    2006-12-12

    In situ images from an award-winning and comprehensive site, The Interactive Fly. Entering through an expression pattern, this site thoroughly discusses each genes and shows its expression relative to other genes at this stage.

  18. SQUID magnetometers for studying corrosion and corrosion protection in aircraft aluminum

    SciTech Connect

    Wikswo, J.P. Jr. [Vanderbilt Univ., Nashville, TN (United States)

    1997-12-01

    Studies at Vanderbilt and elsewhere have demonstrated that superconducting quantum interference (SQUID) magnetometers can be utilized for quantitative measurements of both corrosion activity and material loss in aircraft aluminum alloys. SQUIDs provide sufficient spatial resolution the distribution of hidden corrosion currents can be mapped. The sensitivity of SQUIDs operating at 4 K in liquid helium is such that corrosion can be detected for salt concentrations as low as 1 part per million, and corrosion in 4% NaCl can be detected through 1.4 cm of aluminum. While measurements of the magnetic field from galvanic currents is straightforward in the laboratory, where ferromagnetic fasteners can be eliminated and low frequency noise and the earth`s magnetic field can be shielded, this technique has yet to be demonstrated on aircraft on the flight line. Advanced, low-frequency SQUID eddy current measurements utilizing sheet inducers and phase-sensitive detection offers a depth-selective technique to image material loss deep in aluminum structures. The size of the signal makes this approach highly suitable for implementation with 77 K, liquid- nitrogen cooled SQUIDs. Thus SQUIDs may be useful both for quantitative, laboratory assessment of the rate of hidden corrosion in aircraft samples, and for imaging the extent of second- and third-layer corrosion damage in aircraft. 56 refs.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

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

    PubMed

    Becker, Kaylyn N; Warren, Joseph D

    2015-05-01

    Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the California Current ecosystem were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton. PMID:25994685

  1. Polyclonal antibody generation in rabbit by administration of an organophosphorus acid anhydrolase (OPAA) from squid.

    PubMed

    Hoskin, F C; Steeves, D M; Walker, J E; Woodbury, C T

    1993-10-01

    When a nerve gas hydrolyzing enzyme [organophosphorus acid anhydrolase (OPAA), formerly DFPase] purified from squid hepatopancreas was injected into rabbits, the resulting sera (RAS) inhibited OPAA purified from either squid hepatopancreas or squid optic ganglia. The inhibition was non-competitive, with 50% inhibition at a 1:1,000 serum dilution, and with the limit of inhibition (in effect, a "titer") at approximately 1:10,000. This RAS did not inhibit the distinctly different OPAAs from a mammalian and two bacterial sources. The hepatopancreas-generated RAS also reacted positively to the appropriate enzyme-linked immunosorbent assay (ELISA) at a titer of 1:100,000. In marked contrast, when OPAA purified from squid optic ganglion was injected into rabbits, the resulting sera did not inhibit squid OPAA, and did not give a positive ELISA. Control sera taken from the same rabbits prior to any injection (RS) did not inhibit the OPAAs. These results show another major difference between squid type OPAAs and the OPAAs from other sources, sometimes termed "Mazur type" OPAAs. PMID:8216373

  2. Tempus Fugit: Time Flies

    NSDL National Science Digital Library

    This online exhibit from a prominent American museum explores the character of time -- its impact on our daily lives and its ability to shape and reform human consciousness. Tempus Fugit: Time Flies is a superb exhibit from the Nelson Atkins Museum of Art that uses items from the museum to exemplify different understandings of time. The exhibit features sections on 20th Century Time, World Times, and Conservation Time. Twentieth-century time considers the changing nature of time in the technological age by examining the innovations in graphic and plastic arts inspired by an altered sense of time. The exhibit includes works by Muybridge, Edward Hopper, Salvador Dali, Kandinsky, Rothko, Roy Lichtenstein, and others. The second section, World Times, focuses on the different conceptions of time embodied in art from primitive times to the present and ranges from ancient Native American to Medieval Europe to ancestral Africa to the deeply cosmological perceptions of time in ancient Indian civilizations. Conservation Time takes visitors behind the scenes to see how conservation science can uncover the history of a work's composition and the changes wrought upon it over the course of its lifetime. The Website also offers ideas for teaching using the exhibits. In sum, this is an elegantly constructed and intelligent Website. To be sure, users will want to set aside some time for it as the graphics enforce their own meditative pace upon the viewer.

  3. Flying in Two Dimensions

    E-print Network

    Prakash, Manu

    2011-01-01

    Diversity and specialization of behavior in insects is unmatched. Insects hop, walk, run, jump, row, swim, glide and fly to propel themselves in a variety of environments. We have uncovered an unusual mode of propulsion of aerodynamic flight in two dimensions in Waterlilly Beetles \\emph{(Galerucella)}. The adult beetles, often found in water lilly ponds, propel themselves strictly in a two-dimensional plane on the surface of water via flapping wing flight. Here we analyze the aerodynamics of this peculiar flight mode with respect to forces exerted on the organism during flight. The complexity of 2-D flight is captured by accounting for additional forces beyond gravitational, thrust, lift and drag, exerted on the insect body in 3D flight. Understanding this constrained propulsion mode requires accounting for viscous drag, surface tension, buoyancy force, and capillary-wave drag. Moreover, dramatic differences exist in the magnitude of the resultant forces in 2D vs. 3D flight. Here, in this fluid dynamics video...

  4. [Fear of flying].

    PubMed

    Müller-Ortstein, H; Baumeister, H P

    1999-10-01

    All reliable data and statistics point to the safety of flying. Nevertheless many opinion surveys indicate that every third in the population is affected by aviophobia in one way or the other. Aviophobia is simply a specific phobia from which men and women suffer the same degree. It can be found in all social strata and all occupational groups. Aviophobia is felt in very subjective manners and different ways. The structure of reasons of aviophobia can be very complex, whereas it is somewhat easier to identify immediately the causes. Depending upon the degree of aviophobia different strategies of treatment are indicated. Next to the confrontation theraphy the most wellknown therapy is the systematic desensibilization, classic relaxation methods and cognitive strategies for overcoming the phobia. A high degree of success has been achieved with workshops on aviophobia. These workshops show an increasing tendency. It can be expected that in the future exposition treatment working with virtual realities will also prove successful in overcoming aviophobia. First case studies on the effectivity are all ready available and further effects towards corroborating the effectivity are being plant. Successful with a reduced and minimal input of therapeutic council are also self-management books. In order to master aviophobia, it may be sufficient in cases of less intensivity to work with self-management books in the sense of bibliotherapy. PMID:10568255

  5. Low-frequency excess noise in SQUIDS with YBa2Cu3O7 step-edge junctions

    Microsoft Academic Search

    V. N. Glyantsev; M. Siegel; J. Schubert; W. Zander; A. I. Braginski

    1994-01-01

    We have fabricated RF and DC SQUIDS with step-edge Josephson junctions (SEJ) and YBa2Cu3O7 thin films. The low-frequency noise of these SQUIDS has been investigated as a function of temperature, bias current and magnetic field. Typically, the energy resolution in the white noise region of the DC SQUIDS with an inductance of 45 pH was 3*10-30 J Hz-1 at 77.5

  6. A digital flux-locked loop for high temperature SQUID magnetometer and gradiometer systems with field cancellation

    SciTech Connect

    Kraus, R.H. Jr.; Bracht, R.; Flynn, E.R. [and others

    1996-12-01

    The SQUID sensor is typically operated in a null detector mode where an analogue flux-locked-loop, FLL, provides a negative feedback to maintain linear operation. The modulated SQUID signal is amplified, filtered, demodulated, and integrated in the FLL. The resulting analog signal is a measure of the magnetic field and noise at the SQUID and is also fed back to the modulation and feedback (M & F) coil to null the flux at the SQUID to maintain the linear operating point. Thus, the FLL output signal is proportional to the change in magnetic field at the SQUID pickup coil, provided the slew rate and dynamic range of the SQUID and FLL system are not exceeded. The goal of the work is to advance technologies needed for a practical fieldable SQUID biomagnetic sensor. We used HTC SQUIDs to realize the benefits noted above. We also implemented the FLL algorithm on a digital-signal-processor (DSP) to realize a number of benefits including (1) software control of noise filtering and background rejection to enable unshielded use of SQUID sensors, (2) flux quanta countin and resetting SQUID operating point to increase system slew rate and dynamic range, (3) programmable FLL adaptable to numerous specific applications, (4) digital signal output (up to 32-bit precision), and (5) reduced FLL package cost. This paper presents results of external signal rejection for a sensor system using HTC SQUIDs, preamplifier circuit, and DSP FLL designed and built at our laboratory. We also note a companion paper in these proceedings and other references to the use of DSP in SQUID applications.

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

    DOEpatents

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

    1981-05-22

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

  8. Solid-state ring laser gyro with similar level of performance as its Helium-Neon counterpart

    Microsoft Academic Search

    Sylvain Schwartz; Francois Gutty; Gilles Feugnet; Jean-Paul Pocholle

    2010-01-01

    Thanks to fast vibration of its gain medium, a solid-state ring laser gyro is shown to have a frequency behaviour similar to Helium-Neon commercial products, with potentially equivalent level of angular random walk.

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

    SciTech Connect

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

    1993-08-01

    Several years ago neon-like titanium (Z = 22) was made to lase at 326 {angstrom} on the 3p {yields} 3s (J = 0 {yields} 1) transition. At the time it was suggested that the lasing may be due to resonantly photo-pumping the neon-like titanium 2p {yields} 4d lines using 3s {yields} 2p and 3d {yields} 2p lines in carbon-like and nitrogen-like titanium which results in lasing on the 3p {yields} 3s transition in neon-like titanium. The strongest argument for this explanation was that adjacent elements (scandium and vanadium) did not lase while titanium was unique in having the above mentioned resonance. In addition a prepulse was required to make the titanium lase, suggestive of the formation of a low density plasma, and the plasma was very overstripped, so the above mentioned pump lines should be quite strong for photo-pumping. We have reinvestigated this laser system and will present results which show lasing on the 3p {yields} 3s (J = 0 {yields} 1) transition in neon-like chromium (Z = 24), iron (Z = 26), and nickel (Z = 28) at 285, 255, and 231 {angstrom} 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.

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

    NASA Astrophysics Data System (ADS)

    Wee, B.; Aulenbach, S.

    2011-12-01

    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.

  11. Bloodsucking Insects and Filth-breeding Flies

    NSDL National Science Digital Library

    0000-00-00

    Tutorials on filth flies and insects which bite humans. Each tutorial has 50 questions; incorrect answers lead to additional information. Covers Asian tiger mosquito, black salt marsh mosquito, stable fly, horse flies, deer flies, sand flies, head louse, public louse, bed bug, bloodsucking conenose, house fly, greenbottle flies, bluebottle flies, secondary screwworm fly, vinegar flies, flesh flies, moth flies, eye gnats, humpbacked flies and soldier flies. Requires Windows, and the tutorials must be installed on the computer's hard drive prior to use. Once installed and launched, the tutorials are intuitive to use. Illustrations incorporated into the questions are of high quality and approporiate to the point being illustrated. Some of the illustrated species are of regional significance (southeastern U.S.) and thus may not apply to other geograhic areas. Program includes a tool for recording student performance. These tutorials will be most useful to those particpating in coursework leading to pest management careers, those in general economic entomology courses, and perhaps to students in medical/veterinary courses. $15. Part number SW 156.

  12. Optical parameters of the tunable Bragg reflectors in squid

    PubMed Central

    Ghoshal, Amitabh; DeMartini, Daniel G.; Eck, Elizabeth; Morse, Daniel E.

    2013-01-01

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

  13. Microtransplantation of cellular membranes from squid stellate ganglion reveals ionotropic GABA receptors.

    PubMed

    Conti, Luca; Limon, Agenor; Palma, Eleonora; Miledi, Ricardo

    2013-02-01

    The squid has been the most studied cephalopod, and it has served as a very useful model for investigating the events associated with nerve impulse generation and synaptic transmission. While the physiology of squid giant axons has been extensively studied, very little is known about the distribution and function of the neurotransmitters and receptors that mediate inhibitory transmission at the synapses. In this study we investigated whether ?-aminobutyric acid (GABA) activates neurotransmitter receptors in stellate ganglia membranes. To overcome the low abundance of GABA-like mRNAs in invertebrates and the low expression of GABA in cephalopods, we used a two-electrode voltage clamp technique to determine if Xenopus laevis oocytes injected with cell membranes from squid stellate ganglia responded to GABA. Using this method, membrane patches containing proteins and ion channels from the squid's stellate ganglion were incorporated into the surface of oocytes. We demonstrated that GABA activates membrane receptors in cellular membranes isolated from squid stellate ganglia. Using the same approach, we were able to record native glutamate-evoked currents. The squid's GABA receptors showed an EC(50) of 98 ?mol l(-1) to GABA and were inhibited by zinc (IC(50) = 356 ?mol l(-1)). Interestingly, GABA receptors from the squid were only partially blocked by bicuculline. These results indicate that the microtransplantation of native cell membranes is useful to identify and characterize scarce membrane proteins. Moreover, our data also support the role of GABA as an ionotropic neurotransmitter in cephalopods, acting through chloride-permeable membrane receptors. PMID:23493508

  14. Characteristics of an HTS-SQUID gradiometer with ramp-edge Josephson junctions and its application on robot-based 3D-mobile compact SQUID NDE system

    NASA Astrophysics Data System (ADS)

    Hatsukade, Y.; Hayashi, K.; Shinyama, Y.; Kobayashi, Y.; Adachi, S.; Tanabe, K.; Tanaka, S.

    2011-11-01

    In this paper, we investigated detailed behavior of novel HTS-dc-SQUID gradiometers with ramp-edge Josephson junctions (JJs) in both an ac magnetic field and a dc magnetic field. In the both fields, the novel gradiometers shows the superior performance to the conventional YBa 2Cu 3O 7-x (YBCO) HTS-dc-SQUID gradiometer and a bare HTS-dc-SQUID ring with bicrystal JJs concerning durability against entry and hopping of flux vortices, probably due to their differential pickup coils without a grain boundary and multilayer structure of the ramp-edge JJs. A robot-based compact HTS-SQUID NDE system utilizing the novel gradiometer was reviewed, and detectability of the system to detect non-through cracks in a carbon fiber reinforced plastic (CFRP)/Al double-layer structure was demonstrated. A new excitation coil in which the supplied currents flowed in the orthogonal directions was applied to detect cracks that oriented vertical and parallel to the baseline of the gradiometer.

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    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.

  17. Ontogeny of squid mantle function: changes in the mechanics of escape-jet locomotion in the oval squid, Sepioteuthis lessoniana lesson, 1830.

    PubMed

    Thompson, Joseph T; Kier, William M

    2002-08-01

    In Sepioteuthis lessoniana, the oval squid, ontogenetic changes in the kinematics of the mantle during escape-jet locomotion imply a decline in the relative mass flux of the escape jet and may affect the peak weight-specific thrust of the escape jet. To examine the relationship between ontogenetic changes in the kinematics of the mantle and the thrust generated during the escape jet, we simultaneously measured the peak thrust and the kinematics of the mantle of squid tethered to a force transducer. We tested an ontogenetic series of S. lessoniana that ranged in size from 5 to 40 mm dorsal mantle length (DML). In newly hatched squids, thrust peaked 40 ms after the start of the escape jet and reached a maximum of between 0.10 mN and 0.80 mN. In the largest animals, thrust peaked 70 ms after the start of the escape jet and reached a maximum of between 18 mN and 110 mN. Peak thrust was normalized by the wet weight of the squid and also by the cross-sectional area of the circumferential muscle that provides power for the escape jet. The weight-specific peak thrust of the escape jet averaged 0.36 in newly hatched squid and increased significantly to an average of 1.5 in the largest squids measured (P < 0.01). The thrust per unit area of circumferential muscle averaged 0.25 mN/mm(2) in hatchlings and increased significantly to an average of 1.4 mN/mm(2) in the largest animals tested (P < 0.01). The impulse of the escape jet was also lowest in newly hatched individuals (1.3 mN. s) and increased significantly to 1000 mN. s in the largest squids measured (P < 0.01). These ontogenetic changes in the mechanics of the escape jet suggest (1) that propulsion efficiency of the exhalant phase of the jet is highest in hatchlings, and (2) that the mechanics of the circumferential muscles of the mantle change during growth. PMID:12200252

  18. Isotopic composition of solar wind neon measured by CELIAS\\/MTOF on board SOHO

    Microsoft Academic Search

    R. Kallenbach; F. M. Ipavich; P. Bochsler; S. Hefti; D. Hovestadt; H. Grünwaldt; M. Hilchenbach; W. I. Axford; H. Balsiger; A. Bürgi; M. A. Coplan; A. B. Galvin; J. Geiss; F. Gliem; G. Gloeckler; K. C. Hsieh; B. Klecker; M. A. Lee; S. Livi; G. G. Managadze; E. Marsch; E. Möbius; M. Neugebauer; K.-U. Reiche; M. Scholer; M. I. Verigin; B. Wilken; P. Wurz

    1997-01-01

    We present first results taken from the high-resolution mass time-of-flight spectrometer (MTOF) of the charge, element, and isotope analysis system (CELIAS) experiment on board the Solar and Heliospheric Observatory (SOHO) spacecraft launched in December 1995, concerning the abundance ratios of neon isotopes in the solar wind. We obtain the isotopic ratios 20Ne\\/22Ne=(13.8+\\/-0.7) and 20Ne\\/21Ne=(440+\\/-110), which agree with the values obtained

  19. Soft x-ray lasing in neon-like ions at pump energies below 100 J

    Microsoft Academic Search

    Juerg E. Balmer; Ansgar R. Praeg; Frank Loewenthal

    1997-01-01

    Using the prepulse technique, soft-x-ray lasing is demonstrated on the J equals 0 - 1 transitions of neon-like titanium, chromium, and iron at 32.6, 28.5, and 25.5 nm, respectively, and on the J equals 2 - 1 transitions of copper, zinc, and germanium at 27.9\\/28.5, 26.2\\/26.7, and 23.2\\/23.6 nm, respectively, for pump energies below 100 J, corresponding to irradiances of

  20. Metastable and charged particle decay in neon afterglow studied by the breakdown time delay measurements

    SciTech Connect

    Markovic, V. Lj.; Gocic, S. R.; Stamenkovic, S. N.; Petrovic, Z. Lj. [Department of Physics, University of Nis, P.O. Box 224, 18001 Nis (Serbia); Institute of Physics, P.O. Box 68, 11000 Belgrade (Serbia and Montenegro)

    2007-10-15

    Memory effect--the long time variation of the electrical breakdown time delay on the relaxation time t{sub d}({tau}) in neon--was explained by the Ne({sup 3}P{sub 2}) (1s{sub 5}) metastable state remaining from the preceding glow [Dj. A. Bosan, M. K. Radovic, and Dj. M. Krmpotic, J. Phys. D 19, 2343 (1986)]. However, the authors neglected the quenching processes that reduce the effective lifetime of metastable states several orders of magnitude below that of the memory effect observations. In this paper the time delay measurements were carried out in neon at the pressure of 6.6 mbar in a gas tube with gold-plated copper cathode, and the approximate and exact numerical models are developed in order to study the metastable and charged particle decay in afterglow. It was found that the metastable hypothesis completely failed to explain the afterglow kinetics, which is governed by the decay of molecular neon ions and molecular nitrogen ions produced in Ne{sub 2}{sup +} collisions with nitrogen impurities; i.e., Ne{sub 2}{sup +}+N{sub 2}{yields}N{sub 2}{sup +}+2Ne. Charged particle decay is followed up to hundreds of milliseconds in afterglow, from ambipolar to the free diffusion limit. After that, the late afterglow kinetics in neon can be explained by the nitrogen atoms recombining on the cathode surface and providing secondary electrons that determine the breakdown time delay down to the cosmic rays and natural radioactivity level.

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

    Microsoft Academic Search

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

    2011-01-01

    The adsorption of helium and neon mixtures on single-walled carbon nanotubes (SWCNTs) was investigated at various temperatures\\u000a (subcritical and supercritical) and pressures using canonical Monte Carlo (CMC) simulation. Adsorption isotherms were obtained\\u000a at different temperatures (4, 40, 77 and 130 K) and pressures ranging from 1 to 16 MPa. Separation factors and isosteric enthalpies\\u000a of adsorption were also calculated. Moreover, the adsorption

  2. Low-Temperature Specific Heats of Solid Neon and Solid Xenon

    Microsoft Academic Search

    H. Fenichel; B. Serin

    1966-01-01

    The specific heats of solid neon and xenon have been measured in the temperature range 1.5 to 24°K, using a calorimeter with a mechanical heat switch. Carbon resistance thermometers were calibrated against a gas thermometer and the helium vapor-pressure scale. The results were analyzed to obtain the temperature dependence of the Debye temperature, Thetac(T). In the range 0.020<~TTheta0c<~0.505, the data

  3. Translating the Science of Measuring Ecosystems at a National Scale: Developing NEON's Online Learning Portal

    NASA Astrophysics Data System (ADS)

    Wasser, L. A.; Gram, W.; Goehring, L.

    2014-12-01

    "Big Data" are becoming increasingly common in many fields. The National Ecological Observatory Network (NEON) will be collecting data over the 30 years, using consistent, standardized methods across the United States. These freely available new data provide an opportunity for increased understanding of continental- and global scale processes such as changes in vegetation structure and condition, biodiversity and landuse. However, while "big data" are becoming more accessible and available, integrating big data into the university courses is challenging. New and potentially unfamiliar data types and associated processing methods, required to work with a growing diversity of available data, may warrant time and resources that present a barrier to classroom integration. Analysis of these big datasets may further present a challenge given large file sizes, and uncertainty regarding best methods to properly statistically summarize and analyze results. Finally, teaching resources, in the form of demonstrative illustrations, and other supporting media that might help teach key data concepts, take time to find and more time to develop. Available resources are often spread widely across multi-online spaces. This presentation will overview the development of NEON's collaborative University-focused online education portal. Portal content will include 1) videos and supporting graphics that explain key concepts related to NEON data products including collection methods, key metadata to consider and consideration of potential error and uncertainty surrounding data analysis; and 2) packaged "lab" activities that include supporting data to be used in an ecology, biology or earth science classroom. To facilitate broad use in classrooms, lab activities will take advantage of freely and commonly available processing tools, techniques and scripts. All NEON materials are being developed in collaboration with existing labs and organizations.

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

    Microsoft Academic Search

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

    1989-01-01

    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

  5. Does low-energy helium-neon laser irradiation alter in vitro replication of human fibroblasts

    Microsoft Academic Search

    H. O. Hallman; J. R. Basford; J. F. OBrien; Laura A. Cummins

    1988-01-01

    Cultured human fibroblasts were treated in a controlled, randomized manner to assess the effect of low-energy (0.9 mW) helium-neon (HeNe) laser irradiation on cellular proliferation. Two trials were performed: one with fibroblasts in the third to fourth passage and the other with fibroblasts in the 13th to 14th passage. In each trial, separate plastic petri dishes were inoculated with the

  6. Ultraviolet-visible absorption of small silver clusters in neon: Agn (n = 1-9)

    Microsoft Academic Search

    S. Lecoultre; A. Rydlo; J. Buttet; C. Félix; S. Gilb; W. Harbich

    2011-01-01

    We present optical absorption and fluorescence spectra in the UV-visible range of size selected neutral Agn clusters (n = 1-9) in solid neon. Rich and detailed optical spectra are found with linewidths as small as 50 meV. These spectra are compared to time dependent density functional theory implemented in the TURBOMOLE package. Excellent agreement between theory and experiment is achieved

  7. Atomic Compton profile of neon calculated from an accurate Kohn-Sham potential

    SciTech Connect

    Al-Sharif, A.I. [Department of Physics, Faculty of Science, Yarmouk University, Irbid (Jordan)

    2005-07-15

    The Compton profile of the neon atom is calculated from an accurate Kohn-Sham potential derived from accurate quantum Monte Carlo wave functions. Compared to the experiment, the results are better than the Hartree-Fock ones in the low-wave-vector region. This suggests that the systematic error in the Kohn-Sham formulation in momentum space is relatively small. The first-order Lam-Plazman correction is also calculated. This correction is less than 1% on the average.

  8. Velocity Dependence of the Ionization of Ar, Kr, and Xe on Impact of Metastable Neon Atoms

    Microsoft Academic Search

    S. Y. Tang; A. B. Marcus; E. E. Muschlitz

    1972-01-01

    Measurements of the velocity dependence of the total ionization cross section of argon, krypton, and xenon on impact of thermal-energy metastable neon (Ne*) atoms have been made using a velocity-selected beam of the metastable atoms. The composition (3P2?3P0 ratio) of the Ne* atomic beam has been measured using an inhomogeneous-field deflecting magnet and found to be about 5?1, assuming equal

  9. High-resolution electron impact excitation functions of metastable states of neon, argon, krypton and xenon

    Microsoft Academic Search

    S J Buckman; P Hammond; G C King; F H Read

    1983-01-01

    Electron impact excitation of the lowest-lying metastable states of neon, argon, krypton and xenon have been studied as a function of incident electron energy over the range from threshold to the 2P1\\/2 ionisation potential and at an energy resolution of 20 meV or better. A wealth of structure is observed. Several of the features are very narrow and are coincident

  10. A Monte Carlo simulation of collisional processes in a Townsend discharge in neon

    Microsoft Academic Search

    Željka D. Nikitovi?; Aleksandra I. Strini?; Vladimir D. Stojanovi?; Gordana N. Malovi?; Zoran Lj. Petrovi?

    2007-01-01

    We analyze the experimental and calculated electron excitation coefficients for 2p1–1s2 (Paschen notation) transition of neon determined in parallel plate drift tube for E\\/N values between 20 and 3000Td (E-electric field, N-gas density, 1Td=10?21Vm2). A null-collision Monte Carlo code was employed, representing the transport of electrons, ions and fast neutrals. The contribution of electron reflection at the anode is analyzed.

  11. A Monte Carlo simulation of collisional processes in a Townsend discharge in neon

    Microsoft Academic Search

    Zeljka D. Nikitovic; Aleksandra I. Strinic; Vladimir D. Stojanovic; Gordana N. Malovic; Zoran Lj. Petrovic

    2007-01-01

    We analyze the experimental and calculated electron excitation coefficients for 2p1 1s2 (Paschen notation) transition of neon determined in parallel plate drift tube for E\\/N values between 20 and 3000 Td (E-electric field, N-gas density, 1 Td=10-21 V m2). A null-collision Monte Carlo code was employed, representing the transport of electrons, ions and fast neutrals. The contribution of electron reflection

  12. LETTER TO THE EDITOR: New low-lying mirroring singly and doubly excited resonances in neon

    Microsoft Academic Search

    S. E. Canton; A. A. Wills; T. W. Gorczyca; E. Sokell; J. D. Bozek; G. Turri; M. Wiedenhoeft; X. Feng; N. Berrah

    2003-01-01

    Many new resonances in neon have been discovered by virtue of their LS-forbidden mirroring partial cross section profiles. In particular, all six of the previously undetected 2s22p4(3P)3s([2,4]P)3p(3[S, P, D] 1) resonances have been observed. These results confirm our earlier prediction (Canton-Rogan et al 2000 Phys. Rev. Lett. 85 3113) that mirroring triplet resonances are observable in partial cross sections where

  13. Effect of Helium-Neon Laser Irradiation on Hair Follicle Growth Cycle of Swiss Albino Mice

    Microsoft Academic Search

    S. Shukla; K. Sahu; Y. Verma; K. D. Rao; A. Dube; P. K. Gupta

    2010-01-01

    We report the results of a study carried out to investigate the effect of helium-neon (He-Ne) laser (632.8 nm) irradiation on the hair follicle growth cycle of testosterone-treated and untreated mice. Both histology and optical coherence tomography (OCT) were used for the measurement of hair follicle length and the relative percentage of hair follicles in different growth phases. A positive

  14. Susceptibility of low-chill blueberry cultivars to Mediterranean fruit fly, oriental fruit fly, and melon fly (Diptera: Tephritidae).

    PubMed

    Follett, Peter A; Zee, Francis T; Hamasaki, Randall T; Hummer, Kim; Nakamoto, Stuart T

    2011-04-01

    No-choice tests were conducted to determine whether fruit of southern highbush blueberry, Vaccinium corymbosum L., hybrids are hosts for three invasive tephritid fruit flies in Hawaii. Fruit of various blueberry cultivars was exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), or Bactrocera cucurbitae Coquillet (melon fly) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal development and adult emergence. Each of the 15 blueberry cultivars tested were infested by oriental fruit fly and Mediterranean fruit fly, confirming that these fruit flies will oviposit on blueberry fruit and that blueberry is a suitable host for fly development. However, there was significant cultivar variation in susceptibility to fruit fly infestation. For oriental fruit fly, 'Sapphire' fruit produced an average of 1.42 puparia per g, twice as high as that of the next most susceptible cultivar 'Emerald' (0.70 puparia per g). 'Legacy', 'Biloxi', and 'Spring High' were least susceptible to infestation, producing only 0.20-0.25 oriental fruit fly puparia per g of fruit. For Mediterranean fruit fly, 'Blue Crisp' produced 0.50 puparia per g of fruit, whereas 'Sharpblue' produced only 0.03 puparia per g of fruit. Blueberry was a marginal host for melon fly. This information will aid in development of pest management recommendations for blueberry cultivars as planting of low-chill cultivars expands to areas with subtropical and tropical fruit flies. Planting of fruit fly resistant cultivars may result in lower infestation levels and less crop loss. PMID:21510205

  15. Presolar Grains from Novae: Evidence from Neon and Helium Isotopes in Comet Dust Collections

    NASA Astrophysics Data System (ADS)

    Pepin, Robert O.; Palma, Russell L.; Gehrz, Robert D.; Starrfield, Sumner

    2011-12-01

    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 3He in these particles indicates space exposure to solar wind irradiation of a few decades at most, consistent with origins in cometary dust streams. Measured 4He/20Ne, 20Ne/22Ne, 21Ne/22Ne, and 20Ne/21Ne isotope ratios, and a low upper limit on 3He/4He, are in accord with calculations of nucleosynthesis in neon nova outbursts. Of these, the uniquely low 4He/20Ne and high 20Ne/22Ne ratios are the most diagnostic, reflecting the large predicted 20Ne 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.

  16. Testing of a Neon Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin Lee

    2014-01-01

    Cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks is required for future NASA missions. A cryogenic loop heat pipe (CLHP) can provide a closed-loop cooling system for this purpose and has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A neon CLHP was tested extensively in a thermal vacuum chamber using a cryopump as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components. Tests conducted included loop cool-down from the ambient temperature, startup, power cycle, heat removal capability, loop capillary limit and recovery from a dry-out, low power operation, and long duration steady state operation. The neon CLHP demonstrated robust operation. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully by applying power to both the pump and evaporator without any pre-conditioning. It could adapt to changes in the pump power andor evaporator power, and reach a new steady state very quickly. The evaporator could remove heat loads between 0.25W and 4W. When the pump capillary limit was exceeded, the loop could resume its normal function by reducing the pump power. Steady state operations were demonstrated for up to 6 hours. The ability of the neon loop to cool large areas was therefore successfully verified.

  17. Laser-induced optogalvanic signal oscillations in miniature neon glow discharge plasma.

    PubMed

    Saini, V K

    2013-06-20

    Laser-induced optogalvanic (OG) signal oscillations detected in miniature neon glow discharge plasma are investigated using a discharge equivalent-circuit model. The damped oscillations in OG signal are generated when a pulsed dye laser is tuned to a specific neon transition (1s5?2p2) at 588.2 nm under the discharge conditions where dynamic resistance changes its sign. Penning ionization via quasi-resonant energy transfer collisions between neon gas atoms in metastable state and sputtered electrode atoms in ground state is discussed to explain the negative differential resistance properties of discharge plasma that are attributed to oscillations in the OG signal. The experimentally observed results are simulated by analyzing the behavior of an equivalent discharge-OG circuit. Good agreement between theoretically calculated and experimental results is observed. It is found that discharge plasma is more sensitive and less stable in close vicinity to dynamic resistance sign inversion, which can be useful for weak-optical-transition OG detection. PMID:23842186

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

    SciTech Connect

    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

    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.

  19. Investigation of compression of puffing neon by deuterium current and plasma sheath in plasma focus discharge

    NASA Astrophysics Data System (ADS)

    Kubes, P.; Paduch, M.; Cikhardt, J.; Cikhardtova, B.; Rezac, K.; Klir, D.; Kravarik, J.; Kortanek, J.; Zielinska, E.

    2015-06-01

    This paper presents the results of the research of the influence of compressed neon, injected by the gas-puff nozzle in front of the anode axis by the deuterium current and plasma sheath on the evolution of the pinch, and neutron production at the current of 2 MA. The intense soft X-ray emission shows the presence of neon in the central region of the pinch. During the implosion and stopping of the plasma sheath, the deuterium plasma penetrates into the internal neon layer. The total neutron yield of 1010-1011 has a similar level as in the pure deuterium shots. The neutron and hard X-ray pulses from fusion D-D reaction are as well emitted both in the phase of the stopping implosion and during the evolution of instabilities at the transformation of plasmoidal structures and constrictions composed in this configuration from both gases. The fast deuterons can be accelerated at the decay of magnetic field of the current filaments in these structures.

  20. Anode break excitation in space-clamped squid axons.

    PubMed

    Guttman, R; Hachmeister, L

    1972-05-01

    Strength-duration curves for space-clamped squid axons, using square wave anode breaks as stimuli, established the existence of four distinct regions. For the average experimental axon the intersection of the first two regions, tau(1), occurs at about 7 msec. This agrees with computations based on the Hodgkin-Huxley (HH) equations and corresponds to the accommodation time constant found previously for a linearly rising ramp, as given by the HH equations and as found experimentally. The second break in the curve, tau(2), at about 200 msec, and the third break, tau(3), at 1 sec, are far beyond the range of the HH equations and may be the counterpart in the excitability of the long time constants, which have been apparent from a number of other types of experiments. The regions of the curve before 1 msec and beyond 2 or 3 sec are quite variable and may represent breakdown. Rheobase increases in both experimental and computed axons when temperature is raised. In both experimental and computed axons tau(1) descreases slightly when the temperature is raised from 10 to 15 degrees C. At 20 and 25 degrees C, tau(1) of the experimental axon increases markedly. PMID:5039758

  1. Slow changes of potassium permeability in the squid giant axon.

    PubMed

    Ehrenstein, G; Gilbert, D L

    1966-09-01

    A slow potassium inactivation i.e. decrease of conductance when the inside of the membrane is made more positive with respect to the outside, has been observed for the squid axon. The conductance-potential curve is sigmoid shaped, and the ratio between maximum and minimum potassium conductance is at least 3. The time constant for the change of potassium conductance with potential is independent of the concentration of potassium in the external solution, but dependent upon potential and temperature. At 9 degrees C and at the normal sea water resting potential, the time constant is 11 sec. For lower temperature or more depolarizing potentials, the time constant is greater. The inactivation can be described by modifying the Hodgkin-Huxley equation for potassium current, using one additional parameter. The modified equation is similar in form to the Hodgkin-Huxley equation for sodium current, suggesting that the mechanism for the passive transport of potassium through the axon membrane is similar to that for sodium. PMID:5970562

  2. Squid axon membrane response to white noise stimulation.

    PubMed

    Guttman, R; Feldman, L; Lecar, H

    1974-12-01

    The current from a white noise generator was applied as a stimulus to a space-clamped squid axon in double sucrose gap. The membrane current and the voltage response of the membrane were then amplified, recorded on magnetic tape, and the stimulus was cross-correlated with the response. With subthreshold stimuli, a cross-correlation function resembling that obtained from a resonant parallel circuit is obtained. As the intensity of the input noise is increased, the cross-correlation function resembles that obtained from a less damped oscillatory circuit. When the noise intensity is further increased so that an appreciable frequency of action potentials is observed, an additional component appears in the experimental cross-correlogram. The subthreshold cross-correlogram is analyzed theoretically in terms of the linearized Hodgkin-Huxley equations. The subthreshold axon approximates a parallel resonant circuit. The circuit parameters are temperature dependent, with resonant frequency varying from approximately 100 Hz at 10 degrees C to approximately 250 Hz at 20 degrees C. The Q(10) of the resonant frequency is equal to 1.9. These values are in agreement with values found previously for subthreshold oscillations following a single action potential. PMID:4429772

  3. Calcium content and net fluxes in squid giant axons

    PubMed Central

    1979-01-01

    Axons freshly dissected from living specimens of the tropical squid Dorytheutis plei have a calcium content of 68 mumol/kg of axoplasm. Fibers stimulated at 100 impulses/s in 100 mM Ca seawater increase their Ca content by 150 mumol/kg.min; axons placed in 3 Ca (choline) seawater increase their Ca content by 12 mumol/kg.min. Axons loaded with 0.2--1.5 mmol Ca/kg of axoplasm extruded Ca with a half time of 15- -30 min when allowed to recover in 3 Ca (Na) seawater. The half time for recovery of loaded axons poisoned with carbonyl cyanide p- trifluoromethoxyphenylhydrazone (FCCP) and iodoacetic acid (IAA) is about the same as control axons. Axons placed in 40 mM Na choline seawater (to reduce chemical gradient for Na) or in 40 mM Na, 410 mM K seawater to reduce the electrochemical gradient for Na to near zero either fail to lose previously loaded Ca or gain further Ca. PMID:438774

  4. Progress towards a metastable RF squid (MRFS) qubit

    NASA Astrophysics Data System (ADS)

    Kamal, Archana; Kerman, Andrew; Gustavsson, Simon; Jin, Xiaoyue; Yan, Fei; Gudmundsen, Ted; Hover, David; Sears, Adam; Yoder, Jonilyn; Orlando, Terry; Oliver, William

    2014-03-01

    The MRFS qubit [1] consists of an RF squid with a very high loop inductance, and whose two lowest quantum states are very well-defined, equal and opposite persistent supercurrents. These states can be strongly decoupled from each other, such that spontaneous electromagnetic decay processes of the excited state are extremely slow. Also, the large loop inductance suppresses the magnetic flux sensitivity of the design. We have realized these large inductances with NbN nanowires whose kinetic inductance is around 0.5 ?H. We will discuss experimental progress in measuring MRFS qubits fabricated using these inductors, and expected improvements in coherence. Future directions include studying the dynamics of quantum phase slips through these nanowires. [1] A. J. Kerman, PRL 104, 027002(2010). This research was funded in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA); and by the Asst Secretary of Defense for Research & Engineering under Air Force Contract number FA8721-05-C-0002. All statements of fact, opinion or conclusions contained herein are those of the authors and should not be construed as representing the official views or policies of IARPA, ODNI or the US government

  5. Metabolic efficiency with fast spiking in the squid axon

    PubMed Central

    Moujahid, Abdelmalik; d'Anjou, Alicia

    2012-01-01

    Fundamentally, action potentials in the squid axon are consequence of the entrance of sodium ions during the depolarization of the rising phase of the spike mediated by the outflow of potassium ions during the hyperpolarization of the falling phase. Perfect metabolic efficiency with a minimum charge needed for the change in voltage during the action potential would confine sodium entry to the rising phase and potassium efflux to the falling phase. However, because sodium channels remain open to a significant extent during the falling phase, a certain overlap of inward and outward currents is observed. In this work we investigate the impact of ion overlap on the number of the adenosine triphosphate (ATP) molecules and energy cost required per action potential as a function of the temperature in a Hodgkin–Huxley model. Based on a recent approach to computing the energy cost of neuronal action potential generation not based on ion counting, we show that increased firing frequencies induced by higher temperatures imply more efficient use of sodium entry, and then a decrease in the metabolic energy cost required to restore the concentration gradients after an action potential. Also, we determine values of sodium conductance at which the hydrolysis efficiency presents a clear minimum. PMID:23162461

  6. Spatial long-range interactions in squid giant axons

    NASA Astrophysics Data System (ADS)

    Hanyu, Yoshiro; Matsumoto, Gen

    1991-04-01

    Membrane states and their bifurcation characteristics are studied for the squid giant axon as a function of external Ca 2+ concentration, temperature and externally applied current step. It is well known that the membrane states are divided into two states, resting (R) and spontaneous oscillation (O), according to the Ca 2+ concentration contained in the solution surrounding the axon. The present experiments further clarified that each of these states was further subdivided into higher (H) and lower (L) temperature phases, according to temperature. The spatially unclamped axon in the higher-temperature phase, either in the R or O state, can bifurcate to produce limit-cycle oscillations of action potentials. The bifurcation parameters are external Ca 2+ concentrations and externally applied current for the axon in the O and R states, respectively. Both the axon in the lower-temperature phase and the spatially clamped axon in the higher-temperature phase can bifurcate to produce intermittent oscillations of action potentials. The bifurcation characteristics at or between the higher- and lower-temperature phases are closely related to the spatial properties of the preoscillatory fluctuations along the axon, suggesting that a particular spatial interaction is responsible for the periodically oscillatory dynamics and the bifurcation to it. The molecular origin of the spatial interaction possibly originates from the specific distribution of Na channels, which may be regulated by subaxolemmal cytoskeletons. Electron microscopic experiments and other evidence to support this idea are described.

  7. Optimization of the leak conductance in the squid giant axon.

    PubMed

    Seely, Jeffrey; Crotty, Patrick

    2010-08-01

    We report on a theoretical study showing that the leak conductance density, G{L} , in the squid giant axon appears to be optimal for the action potential firing frequency. More precisely, the standard assumption that the leak current is composed of chloride ions leads to the result that the experimental value for G{L} is very close to the optimal value in the Hodgkin-Huxley model, which minimizes the absolute refractory period of the action potential, thereby maximizing the maximum firing frequency under stimulation by sharp, brief input current spikes to one end of the axon. The measured value of G{L} also appears to be close to optimal for the frequency of repetitive firing caused by a constant current input to one end of the axon, especially when temperature variations are taken into account. If, by contrast, the leak current is assumed to be composed of separate voltage-independent sodium and potassium currents, then these optimizations are not observed. PMID:20866836

  8. Metabolic efficiency with fast spiking in the squid axon.

    PubMed

    Moujahid, Abdelmalik; d'Anjou, Alicia

    2012-01-01

    Fundamentally, action potentials in the squid axon are consequence of the entrance of sodium ions during the depolarization of the rising phase of the spike mediated by the outflow of potassium ions during the hyperpolarization of the falling phase. Perfect metabolic efficiency with a minimum charge needed for the change in voltage during the action potential would confine sodium entry to the rising phase and potassium efflux to the falling phase. However, because sodium channels remain open to a significant extent during the falling phase, a certain overlap of inward and outward currents is observed. In this work we investigate the impact of ion overlap on the number of the adenosine triphosphate (ATP) molecules and energy cost required per action potential as a function of the temperature in a Hodgkin-Huxley model. Based on a recent approach to computing the energy cost of neuronal action potential generation not based on ion counting, we show that increased firing frequencies induced by higher temperatures imply more efficient use of sodium entry, and then a decrease in the metabolic energy cost required to restore the concentration gradients after an action potential. Also, we determine values of sodium conductance at which the hydrolysis efficiency presents a clear minimum. PMID:23162461

  9. Intrinsic noise characteristics of NbN SQUID's

    SciTech Connect

    Cukauskas, E.J.; Nisenoff, M.

    1981-03-01

    Thin-film NbN SQUID's with granular weak links have been fabricated and their rf I-V characteristics measured at 23 MHz. Three different temperature variations of the critical currents were observed. A Josephson-like temperature dependence for those devices with strongly coupled grains and a bulk-mean-field-like dependence for those with the weakest coupled grains were found. An intermediate case where the critical current follows the bulk-mean-field theory at low critical currents and switches over to Josephson-like for larger currents was also observed. The noise properties of these devices were deduced from the measurement of the step rise parameter a. The data were in good agreement with the theory of Kurkijarvi over a wide range of temperature and critical currents for those devices with a bulk-mean-field-like critical current dependence and a low critical current density (approx.10/sup 4/ A/cm/sup 2/). Other devices were in agreement over a much smaller region of temperature and critical current. These devices are rugged, stable, and show very little change in their characteristics after extended storage at room temperature.

  10. Ionic Current Measurements in the Squid Giant Axon Membrane

    PubMed Central

    Cole, Kenneth S.; Moore, John W.

    1960-01-01

    The concepts, experiments, and interpretations of ionic current measurements after a step change of the squid axon membrane potential require the potential to be constant for the duration and the membrane area measured. An experimental approach to this ideal has been developed. Electrometer, operational, and control amplifiers produce the step potential between internal micropipette and external potential electrodes within 40 microseconds and a few millivolts. With an internal current electrode effective resistance of 2 ohm cm.2, the membrane potential and current may be constant within a few millivolts and 10 per cent out to near the electrode ends. The maximum membrane current patterns of the best axons are several times larger but of the type described by Cole and analyzed by Hodgkin and Huxley when the change of potential is adequately controlled. The occasional obvious distortions are attributed to the marginal adequacy of potential control to be expected from the characteristics of the current electrodes and the axon. Improvements are expected only to increase stability and accuracy. No reason has been found either to question the qualitative characteristics of the early measurements or to so discredit the analyses made of them. PMID:13694548

  11. A phylogenetic study of the squid family Onychoteuthidae (Cephalopoda: Oegopsida)

    PubMed Central

    Bonnaud, L.; Rodhouse, P. G.; Boucher-Rodoni, R.

    1998-01-01

    The oegopsid squid family Onychoteuthidae presently comprises six genera (Moroteuthis, Onychoteuthis, Ancistroteuthis, Kondakovia, Onykia and Chaunoteuthis) but the status of some of these is still uncertain. An interdisciplinary study was undertaken to clarify the phylogenetic relationships, which included a morphological approach (morphometric analysis), and a molecular study of a mitochondrial gene portion (l-rRNA gene, 16S). The morphometric analysis identified two groups, one including some Onychoteuthis and some Moroteuthis knipovitchi, and another including the remaining genera or species. At the intrageneric level, M. knipovitchi appears to be separated from the other species of the genus; M. robusta is closely related to M. ingens and M. pacifica. Morphometric analysis confirmed that Kondakovia longimana is different from M. ingens. Likewise, Onychoteuthis was clearly separated from the other genera, but there is neither geographical grouping nor morphometric differentiation of the Onychoteuthis species with the parameters measured. Some specimens were apparently intermediate between the Onychoteuthis and Ancistroteuthis groups. On a molecular basis, the Onychoteuthidae appeared to be monophyletic. Monophyly of the genus Moroteuthis (four species studied) was not strongly supported: M. knipovitchi was distinct from the others. The molecular analysis showed three Hawaiian species, Onychoteuthis compacta, O. sp. B and O. sp. C, to be closely related. The gene sequence for the newly created species of Onykia is clearly different from all the others, indicating that it is a true species.

  12. Metabolic efficiency with fast spiking in the squid axon

    E-print Network

    Moujahid, Abdelmalik; 10.3389/fncom.2012.00095

    2012-01-01

    Fundamentally, action potentials in the squid axon are consequence of the entrance of sodium ions during the depolarization of the rising phase of the spike mediated by the outflow of potassium ions during the hyperpolarization of the falling phase. Perfect metabolic efficiency with a minimum charge needed for the change in voltage during the action potential would confine sodium entry to the rising phase and potassium efflux to the falling phase. However, because sodium channels remain open to a significant extent during the falling phase, a certain overlap of inward and outward currents is observed. In this work we investigate the impact of ion overlap on the number of the adenosine triphosphate (ATP) molecules and energy cost required per action potential as a function of the temperature in a Hodgkin-Huxley model. Based on a recent approach to computing the energy cost of neuronal AP generation not based on ion counting, we show that increased firing frequencies induced by higher temperatures imply more ef...

  13. Thermal instabilities in micro-SQUIDs with long leads

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    We report on Nb film based micron-size superconducting quantum interference devices (?-SQUIDs) with long leads and with constrictions as weak-links (WLs). The current-voltage characteristics (IVCs) of these devices are hysteretic at low temperatures (T) with two re-trapping currents, Ir1 and Ir2, arising from thermal instabilities, and a critical-current (Ic) . We see oscillations with magnetic flux in Ic, but not in Ir1 and Ir2, in both the hysteretic and non-hysteretic regimes. We describe a one dimensional model for thermal instability in long-leads to understand re-trapping currents and its T-dependence. The critical-current shows a marked change in behaviour at the crossover temperature when it meets the lower re-trapping current and above this temperature the critical current subsists due to proximity superconductivity. The thermal stability with respect to phase-slips evolves with temperature and only above the crossover temperature the weak-link can cope with the heat generated by phase-slips giving a non-hysteretic behaviour. Keeping other device dimensions same the WLs' dimensions give a control on the hysteresis-free T-range. NK acknowledges the financial support from CSIR, India as well as CNRS-Institute Néel, Grenoble, France.

  14. Distribution of rhodopsin and retinochrome in the squid retina

    PubMed Central

    1976-01-01

    The cephalopod retina contains two kinds of photopigments, rhodopsin and retinochrome. For many years retinochrome has been thought to be localized in the inner segments of the visual cells, whereas rhodopsin is in the outer segments. However, it is now clear that retinochrome can be extracted also from fragments of outer segments. In the dark- adapted retina of Loligo pealei retinochrome is distributed half-and- half in the inner and outer segments. Todarodes pacificus contains much more retinochrome than Loligo, and it is more abundant in the outer than in the inner segments. The outer segments of Loligo contain retinochrome and metarhodopsin in addition to rhodopsin, whether squids are kept in the dark or in the light. But there is extremely little metarhodopsin (about 3% of rhodopsin) even in light-adapted eyes. The inner segments contain only retinochrome, and much less in the light than in the dark. On the other hand, retinochrome in the outer segments increases markedly during light adaptation. These facts suggest the possibility that some retinochrome moves forward from the inner to the outer segments during light adaptation and there reacts with metarhodopsin to promote regeneration of rhodopsin. PMID:6620

  15. Fly on the Wall

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald

    2003-01-01

    The email was addressed not only to me, but also to all the Project Knowledge Sharing Community at Ames Research Center. We were invited to sit in on a major project review as a new experiment in knowledge sharing. This first-of-its-kind opportunity had been conceived by Claire Smith, who leads the knowledge sharing program, as well as heading up the Center's Project Leadership Development Program and serving as coordinator of the APPL-West program at Ames. The objective was to offer Ames project practitioners the opportunity to observe project-review processes as they happen. Not that I haven't participated in my share of project reviews, but this seemed like a great way for me to get up-to-date about a new project, the Kepler mission, and to experience a review from a new perspective. Typically, when you're being reviewed, it's difficult to see what's happening objectively-the same way it is on a project. Presenters are always thinking, 'Okay, what's on my slides? How much time do I have left? What are they going to ask me?' So when Claire's email pinged on my computer, I quickly responded by asking her to save a place for me. It was to be an informational review about progress on the project: what the team had done, where they were going, and what they needed to do to get there. There were people on the project team from all over the United States, and it was the first time for them to get together from all aspects of the project. For our part, as observers, we were asked to abide by a couple of rules: Don't ask any questions. and don't talk about the specifics of what we saw or heard. The idea was that we weren't supposed to be noticed. We weren't to buzz around and bother people. Hence the name for this experinient: Fly on the Wall.

  16. XMM flying beautifully

    NASA Astrophysics Data System (ADS)

    1999-12-01

    The early orbit phase came to an end on 16 December after XMM had been manoeuvred to its final orbit. This required four firings of its thrusters, on successive passages at apogee, in order to increase XMM's velocity, thus elongating its orbit and raising the perigee from 826 km to 7,365 km. One burn was then made to fine tune the apogee to around 114,000km. The spacecraft, being tracked by ground stations in Perth, Kourou and Villafranca, is now circling the Earth in this highly elliptical orbit once every 48 hours. The XMM flight operations staff have found themselves controlling a spacecraft that responds exceptionally well. During these first orbits, the satellite has been oriented several times with razor-sharp precision. On board systems have responded without incident to several thousand instructions sent by controllers. "XMM is flying so beautifully" says Dietmar Heger, XMM Spacecraft Operations Manager. "The satellite is behaving better in space than all our pre-launch simulations and we have been able to adjust our shifts to this more relaxed situation". On his return from French Guiana, Robert Lainé, XMM Project Manager immediately visited the Darmstadt Mission Control Centre, at ESOC. "The perfect behaviour of XMM at this early stage reflects the constructive cooperation of European industrial companies and top scientists. Spacecraft operations are in the hands of professionals who will endeavour to fulfill the expectations of the astronomers and astrophysicists of the world. I am very happy that ESA could provide them with such a wonderful precision tool". During the early orbit phase, controllers have activated part of XMM's science payload. The three EPIC X-ray cameras have been switched on and vented. On 17 December the telescope doors were opened allowing the spacecraft's golden X-ray Multi Mirror modules to see the sky. The Optical Monitor telescope door was opened on 18 December. During this last weekend, XMM's Radiation Monitor which records the flux of cosmic particles and radiations was switched on. Mission controllers have now placed XMM in a quiescent mode for the Christmas and New Year period. Full operations will resume on 4 January with the start of the spacecraft commissioning phase due to last until 15 February. ESA's XMM Science Operations Centre at Villafranca will be brought online early January allowing the start of the exhaustive calibration and performance verification phase of XMM's science instruments. Progress on this calibration should allow the telescope to target and take "firstlight pictures" of its first X-ray sources next March.

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

    NASA Astrophysics Data System (ADS)

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

    2007-10-01

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

  18. Development of SQUID microscope for localization and imaging of material defects (NDE)

    SciTech Connect

    Kraus, R.H. Jr.; Espy, M.; Atencio, L.

    1997-10-01

    Dramatic progress was made in FY1997, the first full year of implementing a new technique for detecting and imaging material defects in nuclear weapon components. Design, fabrication, and initial tests of a ``SQUID Microscope`` has been completed utilizing the extraordinary sensitivity of High-Critical-Temperature (HTC) Superconducting QUantum Interference Device (SQUID) technology. SQUIDs, the most sensitive magnetic field detectors known, are used to sense magnetic anomalies caused by the perturbation of an induction field by defects in the material under examination. Time variation of the amplitude (A) and angle ({theta}) of an induction field with unique spatial distribution allows examination of material defects as a function of depth and orientation within the sample. Variation of the frequency of amplitude variation, {Omega}(A), enables depth selection in a given sample. Scanning the sample in physical, A, and {theta} space enables detection and localization of defects to high precision. A few examples of the material defects anticipated for study include cracks, stress fractures, corrosion, separation between layers, and material inclusions. Design and fabrication of a prototype SQUID Microscope has been completed during FY97. Extensive testing of the physical, thermal, precision mechanical, and vacuum performance of the SQUID microscope were performed. First preliminary tests of the integrated system have been performed and initial results were obtained in the first week of September 1997, more than 3 months ahead of schedule.

  19. Hydrothermal reactions of fly ash

    SciTech Connect

    Brown, P.W.

    1991-01-01

    The reactions which occur when fly ash is treated under hydrothermal conditions will be investigated. Formation of four classes of compounds, which bracket likely fly ash compositional ranges, have been selected for study. These are calcium silicate hydrates, calcium silicosulfates, calcium aluminosulfates, and alkali aluminosilicates. The specific compounds fabricated will be determined and their stability regions assessed. As a part of stability assessment, the extent to which selected hazardous species are sequestered will be determined. Finally, the cementing properties of these compounds will be established.

  20. Fly America Act and Open Skies Agreements Flying from the USA to a foreign

    E-print Network

    Fly America Act and Open Skies Agreements Flying from the USA to a foreign country on federal America Act. Updated information on the Open Skies Agreements can be found at: Traveling to other foreign must fly on a U.S. flag airline unless you qualify for an exemption as noted in the Fly America Act

  1. House fly oviposition inhibition by larvae of Hermetia illucens , the black soldier fly

    Microsoft Academic Search

    Susan W. Bradley; D. C. Sheppard

    1984-01-01

    Wild populations of house flies were inhibited from ovipositing into poultry manure containing larvae of the black soldier fly,Hermetia illucens (L.). A laboratory strain of house fly responded differently, readily ovipositing into manure with lower densities of soldier fly larvae, but avoiding the higher densities tested. The amount of timeH. illucens larvae occupy the manure prior to an oviposition test

  2. Improving the accuracy of helium and neon measurements in ocean waters

    NASA Astrophysics Data System (ADS)

    Vogt, M.; Roether, W.; Vogel, S.; Sueltenfuss, J.

    2012-04-01

    The helium and neon solubility disequilibria across the ocean-atmosphere interface serve to study the physics of air-sea gas exchange, but the effect is small so that only high-accuracy data give useful results. Weak points are measurement calibration and uncertain solubility equilibrium values in seawater, especially so for the helium isotopes. Calibration: The classical calibration of mass spectrometric helium and neon measurements uses aliquots of atmospheric air, which is convenient but limited in accuracy and long-term stability. Our alternative is to use water samples equilibrated with undisturbed air, so that their mass can be converted into equivalent volumes of air using a solubility function. In this way, the samples allow a precise recalibration of the air aliquots. A bias relative to regular samples is excluded because the equilibrated water is subjected to exactly the same treatment. The equilibration unit has a water capacity of 4.5 liters. The water is circulated over exchange mats, yielding full air-water equilibrium within two hours, and temperature, pressure, and humidity are precisely controlled. In consequence, we achieve solubility equilibrium within ± 0.03%, so that high accuracy and long-term stability of the calibration are guaranteed. The solubility equilibrium values are more uncertain, but a biased value will only introduce a common shift to the data, i.e., it will not affect the internal consistency of the calibration. The new calibration mode will also enable efficient intercalibration between laboratories. Solubility determination and sampling procedures: We shall use the equilibration unit to obtain solubility functions of helium and neon in distilled water and seawater with a projected accuracy of ± 0.2%. One measure to achieve this is to compare the mass spectrometric signals of the water and the air phase directly. In this context, we developed a procedure to sample water into glass ampoules to be flame-sealed. They are filled about half, which means that the gas in the head space can directly be admitted into the mass spectrometer, because only about 1% of the helium and neon remains in solution. The uncertainty of the helium and neon concentrations introduced by the procedure does not exceed ± 0.05% and blanks are about negligible. The device is simple and handling fast. Experience on a cruise into the tropical Atlantic has proven that the sampling procedure can be applied reliably in the field. We also devised a way to transfer air samples into identical ampoules.

  3. Developing a Scalable Remote Sampling Design for the NEON Airborne Observation Platform (AOP)

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The National Ecological Observatory Network (NEON) airborne observation platform (AOP) will collect co-registered high-resolution hyperspectral imagery, discrete and waveform LiDAR, and high-resolution digital photography for more than 60 terrestrial and 23 aquatic sites spread across the continental United States, Puerto Rico, Alaska and Hawaii on an annual basis over the next 30 years. These data, to be made freely available to the public, will facilitate the scaling of field-based biological, physical and chemical measurements to regional and continental scales, enabling a better understanding of the relationships between climate variability and change, land use change and invasive species, and their ecological consequences in areas not directly sampled by the NEON facilities. However, successful up-scaling of in situ measurements requires a flight sampling design that captures environmental heterogeneity and diversity (i.e., ecological and topographic gradients), is sensitive to temporal system variation (e.g., phenology), and can respond to major disturbance events. Alignment of airborne campaigns - composed of two payloads for nominal science acquisitions and one payload for PI-driven rapid-response campaigns -- with other ground, airborne (e.g., AVIRIS) and satellite (e.g., Landsat, MODIS) collections will further facilitate scaling between sensors and data sources of varying spatial and spectral resolution and extent. This presentation will discuss the approach, challenges and future goals associated with the development of NEON AOP's sampling design, using examples from the 2013 nominal flight campaigns in the Central Plains (NEON Domain 10) and the Pacific Southwest (Domain 17), and the rapid response flight campaign of the High Park Fire site outside of Fort Collins, CO. Determination of the specific flight coverage areas for each campaign involved analysis of the landscape scale ecological, geophysical and bioclimatic attributes and trends most closely associated with the primary science questions NEON data is addressing in each domain. An effort was made to capture the range of spatial and temporal variability at each site and across multiple sites so as to enable the science community to extrapolate across multiple scales, from organisms to landscapes to domain- and continental-scales using a variety of field and remotely sensed data.

  4. 986 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 13, NO. 2, JUNE 2003 Effects of Pulse Shape on rf SQUID Quantum Gates

    E-print Network

    Chu, Shih-I

    Shape on rf SQUID Quantum Gates Zhongyuan Zhou, Shih-I Chu, and Siyuan Han Abstract--Effects of control-signal microwave pulse shapes on rf SQUID quantum gates are investigated. It is shown that the gate operations Terms--Pulse shaping methods, quantum computers, SQUID qubits. I. INTRODUCTION RECENTLY, quantum

  5. ANOMALOUS BEHAVIOR OF THE RF-SQUID IN THE NON-HYSTERETIC CASE : DC-FLUX DEPENDENCE OF THE OUTPUT SIGNAL WITH PERIOD 0/2

    E-print Network

    Paris-Sud XI, Université de

    ANOMALOUS BEHAVIOR OF THE RF-SQUID IN THE NON-HYSTERETIC CASE : DC-FLUX DEPENDENCE OF THE OUTPUT and theoretical results are in agreement. From the general theory for the non-hysteretic SQUID conditions have circuit voltage U of an RF-biased SQUID is a periodical function of the applied dc-magnetic flux

  6. JOURNAL DE PHYSIQUE Colloque C6, supplkmenr au no 8, Tome 39, aozir 1978,page ~6-1206 MEASUREMENTS OF SQUID EQUIVALENT CIRCUIT PARAMETERS

    E-print Network

    Boyer, Edmond

    OF SQUID EQUIVALENT CIRCUIT PARAMETERS G.J. Ehnholm, S.T. Islander, P. 'Cfstman and B. Rantala Low equivalent complet pour le SQUID-rf a 6td prSsent6 par Ehnholm. Nous prdsentons des mesures qui vdrifient ce circuit et dsmontrent ses propristss. Abstract.- A complete equivalent circuit for the rf SQUID has been

  7. Nano-sized SQUID-on-tip for scanning probe A Finkler1, D Vasyukov1, Y Segev1, L Neeman1, Y Anahory1,

    E-print Network

    Zeldov, Eli

    Nano-sized SQUID-on-tip for scanning probe microscopy A Finkler1, D Vasyukov1, Y Segev1, L Neeman1 present a SQUID of novel design, which is fabricated on the tip of a pulled quartz tube in a simple 3-step devices have SQUID loops with typical diameters in the range 75 - 300 nm. They operate in magnetic fields

  8. Draft Genome Sequence of Vibrio fischeri SR5, a Strain Isolated from the Light Organ of the Mediterranean Squid Sepiola robusta

    E-print Network

    McFall-Ngai, Margaret

    of the Mediterranean Squid Sepiola robusta Mattias C. Gyllborg,a Jason W. Sahl,b David C. Cronin III,a David A. Rasko genome sequence of Vibrio fischeri SR5, a squid symbiotic isolate from Sepiola robusta in the Medi symbiont and the first from outside the Pacific Ocean. Vibrio-squid mutualisms represent valuable models

  9. PROBING PARING SYMMETRY OF SUPERCONDUCTORS BY USING r.f. SQUID Y.D. Dai, S.G. Wang and S.W. Du*

    E-print Network

    Du, Shengwang

    PROBING PARING SYMMETRY OF SUPERCONDUCTORS BY USING r.f. SQUID Y.D. Dai, S.G. Wang and S.W. Du charac- teristics of radio frequency superconducting quantum interference device (r.f. SQUID). We can be detected through the applied magnetic flux, at which the SQUID coupled to a tank circuit has

  10. JOURNAL DE PHYSIQUE Colloque C6, supplment au n 8, Tome 39, aot 1978, page C6-1613 "NMR DETECTION WITH THE SQUID -APPLICATION TO LIQUID 3

    E-print Network

    Paris-Sud XI, Université de

    DETECTION WITH THE SQUID - APPLICATION TO LIQUID 3 H e " + R.A. Webb+ Argonne National Laboratory, Argonne'expériences de résonnance magnétique utilisant un SQUID. On traite en particulier le cas des mesures de for performing a variety of magnetic resonance expe- riments using a SQUID is presented. In particular

  11. Quantum Information Transfer and Entanglement with SQUID Qubits in Cavity QED: A Dark-State Scheme with Tolerance for Nonuniform Device Parameter

    E-print Network

    Chu, Shih-I

    Quantum Information Transfer and Entanglement with SQUID Qubits in Cavity QED: A Dark-State Scheme of realizing quantum information transfer (QIT) and entanglement with SQUID qubits in a microwave cavity via with two-SQUID qubits can be achieved with a high fidelity. The present scheme is tolerant to device

  12. INTEGRATION OF SQUID l/f NOISE AND ITS APPLICATION TO A SUPERCONDUCTING GYROSCOPE J.T. Anderson and B. Cabrera

    E-print Network

    Paris-Sud XI, Université de

    INTEGRATION OF SQUID l/f NOISE AND ITS APPLICATION TO A SUPERCONDUCTING GYROSCOPE J.T. Anderson Abstract.- SQUID noise in the 1/f noise region was integrated for 140 hours in a narrow frequency band. INTRODUCTION.- SQUID magnetometers exhibit increa- sing noise power at low frequencies /l/ which tends to rise

  13. Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers Ian K. Bartol, Paul S. Krueger, William J. Stewart and Joseph T. Thompson

    E-print Network

    Hynes, Wayne L.

    Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers Ian K. Bartol, Paul S of various appendages, squid paralarvae (hatchlings) employ a pulsed jet for locomotion at intermediate Re. [The term paralarvae is used because squid hatchlings exhibit behavioral and ecological characteristics

  14. Sensory, microbiological, physical and chemical properties of cuttlefish ( Sepia officinalis) and broadtail shortfin squid ( Illex coindetii) stored in ice

    Microsoft Academic Search

    Paulo Vaz-Pires; Pedro Seixas; Micaela Mota; Judite Lapa-Guimarães; Jana Pickova; Andreia Lindo; Teresa Silva

    2008-01-01

    The objective of this study was to characterize whole raw cuttlefish (Sepia officinalis) and shortfin squid (Illex coindetii) during storage in ice through sensory, microbiological, chemical and physical analyses. The recently developed Quality Index Method (QIM) tables for these species were used for sensory analysis. Shelf-life of whole cuttlefish and shortfin squid were estimated as around 10 and 9 days,

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

    E-print Network

    Benoit-Bird, Kelly J.

    Controlled and in situ target strengths of the jumbo squid Dosidicus gigas and identification 2007; accepted 12 December 2007 This study presents the first target strength measurements of Dosidicus. Target strength of live, tethered squid was related to mantle length with values standardized

  16. Plus-end Motors Override Minus-end Motors during Transport of Squid Axon Vesicles on Microtubules

    E-print Network

    Muresan, Virgil

    vesicle populations. The additional finding that kinesin overrides cytoplasmic dynein when both are boundPlus-end Motors Override Minus-end Motors during Transport of Squid Axon Vesicles on Microtubules- and minus-end vesicle populations from squid axoplasm were isolated from each other by selective extraction

  17. Many squid rely on jet propulsion for locomotion, which is inherently less efficient than the undulatory/oscillatory

    E-print Network

    Hynes, Wayne L.

    Many squid rely on jet propulsion for locomotion, which is inherently less efficient than the undulatory/oscillatory locomotion employed by many fishes (Vogel, 1994). Jet propulsion is thought, such as Salmo spp., and certain squid that rely heavily on jet propulsion for locomotion, such as Illex

  18. Magnetic susceptibility and order parameter of nematic liquid crystals as determined by a high-temperature SQUID magnetometer

    Microsoft Academic Search

    Th. Dries; K. Fuhrmann; E. W. Fischer; M. Ballauff

    1991-01-01

    The design and operation of a high-temperature measuring cell for SQUID magnetometers is described. It is demonstrated this device is well suited for precision measurements of magnetic susceptibility up to approximately 600 K. Thus, the SQUID method can be employed for the study of phase transitions of most thermotropic liquid crystals and LC polymers. To access the influence of molecular

  19. Diapause potential in tropical flesh flies

    Microsoft Academic Search

    David L. Denlinger

    1974-01-01

    FLESH flies (Diptera: Sarcophagidae) of the temperate region use the short, cool days of late summer and early autumn as a reliable cue to signal the advent of winter1,2. Flies may enter an overwintering pupal diapause in August, and the adults will not emerge until the following May2. Tropical flies, by contrast, are not exposed to a regularly occurring season

  20. The Hessian Fly [Mayetiola destructor (say)

    NSDL National Science Digital Library

    0000-00-00

    The information provided includes information concerning the morphology, distribution, hosts, damage, and life cycles of the Hessian Fly. Also includes a listing of Hessian fly research labs and a bibliography in regard to pest management. The work is succinct. It gives a good overview on the Hessian fly. Internet is needed to access the information.

  1. John Glenn: His first Flying Lesson Remembered

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Pilot Harry Clever remembers giving John Glenn his first flying lesson. From: The John Glenn Story: Summary of astronaut John Glenn's flying career, from naval aviation training to space flight. The Mercury project is featured as John Glenn flies the Friendship 7 spacecraft. President John F. Kennedy presents the NASA Distinguished service Medal to Astronaught John Glenn.

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

    E-print Network

    W. Wang; X. -W. Liu

    2008-06-13

    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 <= 8.0) but not at metallicity higher than the SMC. The fact that Ne/O ratios measured in PNe are almost the same as those in HII regions, regardless of the metallicity, suggests a very similar production mechanism of neon and 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.

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

    PubMed

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

    1999-06-01

    The good nutritional properties of meat from big squid (Dosidicus gigas) living on the Chilean coast, was determined through its proximal composition 70 cal/100 g fresh meat; 82.23 +/- 0.98% moisture; 15.32 +/- 0.93% protein; 1.31 +/- 0.12% ashes; 0.87 +/- 0.18% fat and 0.27% NNE (non-nitrogen extract). The big squid meat was used to develop a gel product which contained NaCl and TPP. It was necessary to use additives for gel preparation, such as carragenin or alginate or egg albumin, due to the lack of gelation properties of squid meat. Formulations containing egg albumin showed the highest gel force measured by penetration as compared to those that contained carragenin or alginate. PMID:10488395

  4. Cryogenic time-domain multiplexer based on SQUID arrays and superconducting/normal conducting switches

    NASA Astrophysics Data System (ADS)

    Beev, N.; Kiviranta, M.; van der Kuur, J.; Bruijn, M.; Brandel, O.; Linzen, S.; Fritzsch, L.; Ahoranta, J.; Penttilä, J.; Roschier, L.

    2014-05-01

    We have demonstrated the operation of a 12-channel Beyer-style SQUID-based time domain multiplexer. It was manufactured using a fabrication process that is cross-compatible between VTT and IPHT-Jena. The multiplexer consists of twelve 12-SQUID series arrays, each shunted by a Zappe-style interferometer array acting as a flux-controlled superconducting/normal conducting switch. By keeping all switches but one in the superconducting state, it is possible to select one active readout channel at a time. A flux feedback coil common to all SQUID arrays allows realization of a flux-locked loop. We present characteristics of the multiplexer and measurement data from experiments with a 25-pixel X-ray calorimeter array operated at T < 100 mK in a dilution refrigerator.

  5. Range-finding in squid using retinal deformation and image blur.

    PubMed

    Chung, Wen-Sung; Marshall, Justin

    2014-01-20

    Squid and other cephalopods catch prey with remarkable speed and precision [1]. Before the strike occurs, they encounter the difficult task of judging an object's distance and size in the contrast-poor world of the mid-water environment [1-4]. Here we describe a solution to this common problem underwater, where a large portion of a squid's dorso-temporal retina is intentionally blurred. This apparently counter-adaptive 'retinal bump' is combined with a vertical bobbing behavior that scans objects of interest from focused to defocused retinal regions. The image focus differential changes sharply at precisely the distance equivalent to tentacle length and enables the squid, Sepioteuthis lessoniana, to capture prey. This unique range-finding mechanism is an adaptation to hunting, defense, and object size identification in an environment where the depth cues found on land are less reliable. PMID:24456975

  6. Adsorbed Oxygen Molecules as a Source of Flux Noise in SQUIDs

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Wang, Zhe; Hu, Jun; Shi, Chuntai; Yu, Clare C.; Wu, Ruqian; Department of Physics, Fudan University, Shanghai 200433, China Collaboration; Department of Physics; Astronomy, University of California, Irvine, CA 92697-4575, USA Collaboration

    2015-03-01

    A major obstacle for using superconducting quantum interference devices (SQUIDs) as qubits is the flux noise generated by fluctuating magnetic spins on the surface of SQUIDs. Using density functional theory (DFT) calculations, we investigated O2 adsorbates and various vacancies on an ?-alumina surface as spin candidates. Their spectroscopic features are directly compared to experimental data using the x-ray magnetic circular dichroism. The calculated magnetic anisotropy energy for the spin of O2 to rotate within a plane perpendicular to the axis of the O-O bond is only about 12 mK (or ~ 1 ?eV) so we believe that O2 molecules are the main source of flux noise in Al SQUIDs. Work at Fudan was supported by the 1000-Telent funds. Work at UCI was supported by DOE-BES (Grant No. DE- FG02-05ER46237) and by NERSC for computing time.

  7. Reading, writing and squeezing the entangled states of two nanomechanical resonators coupled to a SQUID

    E-print Network

    Guy Z. Cohen; Massimiliano Di Ventra

    2013-02-07

    We study a system of two nanomechanical resonators embedded in a dc SQUID. We show that the inductively-coupled resonators can be treated as two entangled quantum memory elements with states that can be read from, or written on by employing the SQUID as a displacement detector or switching additional external magnetic fields, respectively. We present a scheme to squeeze the even modeof the state of the resonators and consequently reduce the noise in the measurement of the magnetic flux threading the SQUID. Wefinally analyze the effect of dissipation on the squeezing using the quantum master equation, and show the qualitatively differentbehavior for the weak and strong damping regimes. Our predictions can be tested using current experimental capabilities.

  8. Slow swimming, fast strikes: effects of feeding behavior on scaling of anaerobic metabolism in epipelagic squid.

    PubMed

    Trueblood, Lloyd A; Seibel, Brad A

    2014-08-01

    Many pelagic fishes engage prey at high speeds supported by high metabolic rates and anaerobic metabolic capacity. Epipelagic squids are reported to have among the highest metabolic rates in the oceans as a result of demanding foraging strategies and the use of jet propulsion, which is inherently inefficient. This study examined enzymatic proxies of anaerobic metabolism in two species of pelagic squid, Dosidicus gigas and Doryteuthis pealeii (Lesueur 1821), over a size range of six orders of magnitude. We hypothesized that activity of the anaerobically poised enzymes would be high and increase with size as in ecologically similar fishes. In contrast, we demonstrate that anaerobic metabolic capacity in these organisms scales negatively with body mass. We explored several cephalopod-specific traits, such as the use of tentacles to capture prey, body morphology and reduced relative prey size of adult squids, that may create a diminished reliance on anaerobically fueled burst activity during prey capture in large animals. PMID:25079893

  9. First-ever observations of a live giant squid in the wild.

    PubMed

    Kubodera, Tsunemi; Mori, Kyoichi

    2005-12-22

    The giant squid, Architeuthis, is renowned as the largest invertebrate in the world and has featured as an ominous sea monster in novels and movies. Considerable efforts to view this elusive creature in its deep-sea habitat have been singularly unsuccessful. Our digital camera and depth recorder system recently photographed an Architeuthis attacking bait at 900 m off Ogasawara Islands in the North Pacific. Here, we show the first wild images of a giant squid in its natural environment. Recovery of a severed tentacle confirmed both identification and scale of the squid (greater than 8 m). Architeuthis appears to be a much more active predator than previously suspected, using its elongate feeding tentacles to strike and tangle prey. PMID:16321779

  10. The development of a fully portable, cryocooled HTS SQUID NDE instrument

    NASA Astrophysics Data System (ADS)

    Carr, C.; Macfarlane, J. C.; Donaldson, G. B.

    2002-08-01

    Commercial realisation of the full potential of HTS SQUIDs in NDE will only come about with the development of fully portable systems that operate on a turn-key approach. Existing cryogenic solutions rely on invertible cryostats which can be both cumbersome and are typically custom-fabricated. With the use of cryocoolers becoming more widespread, there is a possibility to dispense with the need for a liquid cryogen. Here we report on progress towards such a system that will incorporate a cryocooler which can be disengaged from a copper thermal battery once the base temperature has been reached. The battery has been designed with a two-stage inner and outer core system to extend the SQUIDs operating time. The cool-down and warm-up rates for the system are presented along with a discussion of SQUID packaging.

  11. Adjusting the dc-SQUID working point by a flux trapping loop for readout of gap-tunable flux qubit

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaobo; Wu, Yulin; Deng, Hui; Zheng, Yarui; Akhtar, Naheed; Fan, Jie; Zheng, Dongning; Lu, Li

    2015-03-01

    When the flux qubit is readout by a dc-SQUID, normally people use a coil to bias both the qubit and the dc-SQUID. However, if the working point of the qubit is located on the bottom or the top of the dc-SQUID's critical current modulation region, the readout is hardly carried out. We insert a flux trapping loop into the readout dc-SQUID. By trapping different numbers of fluxoids in the loop, the flux bias of the dc-SQUID can be changed accordingly, while the flux bias of the qubit changes very little because of the very small mutual inductance between the qubit and the trap loop. This improvement enables us to carry out the readout in the complicate experiments of gap-tunable flux qubit.

  12. The Home Zone: Flying Together

    NSDL National Science Digital Library

    2003-02-01

    Airplanes, like kites and other flying objects, are of great interest to elementary children. Like the Wright brothers and countless other aviation pioneers, children seem to enjoy the process of designing, making, and modifying airplanes. The following activities introduce a few basic laws of physics and bring out the "inventor" in everyone as families experiment and test their own paper airplane models.

  13. Alkali-activated fly ashes

    Microsoft Academic Search

    A. Palomo; M. W. Grutzeck; M. T. Blanco

    1999-01-01

    The alkali activation of waste materials (especially those coming from industrial and mining activities) has become an important area of research in many laboratories because it is possible to use these materials to synthesize inexpensive and ecologically sound cementlike construction materials. In the present paper, the mechanism of activation of a fly ash (no other solid material was used) with

  14. Flying Through the Fear Barrier

    Microsoft Academic Search

    Wladyslaw Bartoszewski

    1985-01-01

    The story of the TKN — the Society for Academic Courses, known as the ‘Flying University’ — which was set up to counter the omissions and distortions in state education. ‘Our greatest achievement was breaking the barrier of fear, bringing people together for the purpose of self-education, and simply sustaining the will to carry on.’Two distinguished representatives of the thriving

  15. Physics between a Fly's Ears

    ERIC Educational Resources Information Center

    Denny, Mark

    2008-01-01

    A novel method of localizing the direction of a source of sound has evolved in the auditory system of certain small parasitic flies. A mechanical model of this design has been shown to describe the system well. Here, a simplified version of this mechanical model is presented which demonstrates the key feature: direction estimates of high accuracy…

  16. Sleep and the fruit fly

    Microsoft Academic Search

    Ralph J. Greenspan; Giulio Tononi; Chiara Cirelli; Paul J. Shaw

    2001-01-01

    The function of sleep remains a long-standing mystery in neurobiology. The presence of a sleep-like state has recently been demonstrated in the fruit fly, Drosophila melanogaster, meeting the essential behavioral criteria for sleep and also showing pharmacological and molecular correlates of mammalian sleep. This development opens up the possibility of applying genetic analysis to the identification of key molecular components

  17. Japanese free-flying satellites

    Microsoft Academic Search

    K. Kuriki; M. Nagatomo; H. Okuda; T. Yamanaka

    1983-01-01

    The results of a design study of a free flying platform that would act in concert with a space station and carry multiple experiments are reported. Concepts were developed for astronomy and astrophysics applications and for experiments featuring large electrical consumption and concommitant high levels of electromagnetic noise. The space station would furnish high data rate processing, supplies of consumables

  18. Learning to Fly Claude Sammut

    E-print Network

    Sammut, Claude

    simulation program has been modified to log the actions of a human subject as he or she flies an aircraft experiments with a particular aircraft simulation and discuss the problems encountered and how they were mechanism of the simulator is a loop that interrogates the aircraft controls and updates the state

  19. Let's Go Fly a Kite!

    NSDL National Science Digital Library

    Jacqueline Leonard

    2002-10-01

    Adults and children of all ages and cultures have either seen a kite or have flown one. Why not use this common pastime to teach some of the simple laws of aerodynamics? Making kites and then flying them can motivate children--especially urban children--to

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

    PubMed

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

    2014-01-01

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