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Sample records for neon flying squid

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

    PubMed

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

    2014-08-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  4. Characteristic of lipids and fatty acid compositions of the neon flying squid, Ommastrephes bartramii.

    PubMed

    Saito, Hiroaki; Ishikawa, Satoru

    2012-01-01

    The lipids and fatty acids of the neon flying squid (Ommastrephes bartramii) were an-alyzed to clarify its lipid physiology and health benefit as marine food. Triacylglycerols were the only major component in the digestive gland (liver). In all other organs (mantle, arm, integument, and ovary), sterols and phospholipids were the major components with noticeable levels of ceramide aminoethyl phosphonate and sphingomyelin. The significant levels of sphingolipids suggest the O. bartramii lipids is a useful source for cosmetics. Although the lipid content between the liver and all other tissues markedly differed from each other, the same nine dominant fatty acids in the triacylglycerols were found in all organs; 14:0, 16:0, 18:0, 18:1n-9, 20:1n-9, 20:1n-11, 22:1n-11, 20:5n-3 (icosapentaenoic acid, EPA), and 22:6n-3 (docosahexaenoic acid, DHA). Unusually high 20:1n-11 levels in the O. bartramii triacylglycerols were probably characteristic for western Pacific animal depot lipids, compared with non-detectable levels of 20:1n-11 reported in other marine animals. O. bartramii concurrently has high levels of DHA in their triacylglycerols. The major fatty acids in the phospholipids were 16:0, 18:0, 20:1n-9, EPA, and DHA without 20:1n-11. Markedly high levels of both EPA and DHA were observed in phosphatidylethanolamine, while only DHA was found as the major one in phosphatidylcholine. In particular, high levels of DHA were found both in its depot triacylglycerols and tissue phospholipids in all organs of O. bartramii, similar to that in highly migratory fishes. The high DHA levels in all its organs suggest that O. bartramii lipids is a healthy marine source for DHA supplements. PMID:23018852

  5. A review of interaction between neon flying squid ( Ommastrephes bartramii) and oceanographic variability in the North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Chen, Xinjun; Yi, Qian; Tian, Siquan

    2015-08-01

    The neon flying squid ( Ommastrephes bartramii) is a short-lived opportunistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continuously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interaction between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including El Niño, La Niña, Kuroshio, Oyashio and Pacific Decadal Oscillation (PDO), as well as regional environmental variables such as sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), chlorophyll-a (Chl- a) concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events ( e.g., Kuroshio and Oyashio Currents) rather than other local environmental conditions ( e.g., SST and Chl- a concentration), because all of the oceanographic influences are imposed on the context of large-scale climate changes ( e.g., PDO). An unstructured-grid finite-volume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceanographic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relationship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae.

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

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Chen, Xinjun; Yi, Qian

    2016-06-01

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

  7. 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

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

    PubMed

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-10-01

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

  10. 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.

  11. A comparison of fishery biology of jumbo flying squid, Dosidicus gigas outside three Exclusive Economic Zones in the Eastern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Liu, Bilin; Chen, Xinjun; Yi, Qian

    2013-05-01

    Although many studies on the fishery biology of jumbo flying squid, Dosidicus gigas, have been conducted in the coastal areas within Exclusive Economic Zones (EEZs) of various countries due to its commercial and ecological importance, limited biological information is available from waters outside these EEZs. In this paper, we examined D. gigas fishery biology from waters outside Chilean, Peruvian and Costa Rican EEZs, based on the fishery data collected by Chinese jigging vessels during 2006 to 2010. The dominant mantle lengths of D. gigas were 350-450 mm, 250-400 mm and 250-350 mm outside Chilean, Peruvian and Costa Rican EEZs, respectively. Size structure analysis show that a medium-sized group existed mostly in the waters outside the Chilean and Peruvian EEZs, whereas a small-sized group occurred mainly in the waters outside the Costa Rican EEZ. The longevity of the squid outside the Costa Rican EEZ was less than 10 months, while most of those outside Chilean and Peruvian EEZs were about 1-1.5 years and very few large individuals were 1.5-2 years old. A higher percentage of mature individuals existed outside Costa Rican EEZ implying the region as a potential spawning ground, while lower proportions of mature squid outside the Peruvian and Chilean EEZs indicated that spawning may be occurring outside our study area. Spatial differences in sizes at maturity of the squid are thought to be result from different environmental factors especially different temperature and nutrition among the three areas. Stomach-content analysis showed that cannibalism was important in the diet of D. gigas. Stress generated by jigging may increase the incidence of cannibalism.

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

    ERIC Educational Resources Information Center

    Delaware Univ., Newark. Coll. of Education.

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

  13. FLIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Squid rocket science: How squid launch into air

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  15. The Squid Challenge.

    ERIC Educational Resources Information Center

    Guillaume, Andrea M.

    1997-01-01

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

  16. 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.

  17. 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.

  18. Subranging scheme for SQUID sensors

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor)

    2008-01-01

    A readout scheme for measuring the output from a SQUID-based sensor-array using an improved subranging architecture that includes multiple resolution channels (such as a coarse resolution channel and a fine resolution channel). The scheme employs a flux sensing circuit with a sensing coil connected in series to multiple input coils, each input coil being coupled to a corresponding SQUID detection circuit having a high-resolution SQUID device with independent linearizing feedback. A two-resolution configuration (course and fine) is illustrated with a primary SQUID detection circuit for generating a fine readout, and a secondary SQUID detection circuit for generating a course readout, both having feedback current coupled to the respective SQUID devices via feedback/modulation coils. The primary and secondary SQUID detection circuits function and derive independent feedback. Thus, the SQUID devices may be monitored independently of each other (and read simultaneously) to dramatically increase slew rates and dynamic range.

  19. Optical fiber feedback SQUID magnetometer

    SciTech Connect

    Naito, S.; Sampei, Y.; Takahashi, T. )

    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.

  20. Low-noise SQUID

    DOEpatents

    Dantsker, Eugene; Clarke, John

    2000-01-01

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

  1. Low-noise SQUID

    SciTech Connect

    Dantsker, E.; Clarke, J.

    2000-02-08

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

  2. Geophysical applications of squids

    SciTech Connect

    Clarke, J.

    1983-05-01

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

  3. SQUIDs - ultimate magnetic sensors

    NASA Astrophysics Data System (ADS)

    Donaldson, Gordon B.

    2005-03-01

    SQUIDs (Superconducting Quantum Interference Devices) have extreme electromagnetic energy sensitivity, which can be applied in a wide variety of ways. Some of these are covered in the papers representing the rest of this symposium: in this brief introductory paper we indicate the wide extent of the full range of applications to which they have been put, from bioscience to tests of General Relativity.

  4. SQUIDs: Then and Now

    NASA Astrophysics Data System (ADS)

    Clarke, John

    2014-03-01

    In 1964, Jaklevic, Lambe, Silver and Mercereau demonstrated quantum interference in a superconducting ring containing two Josephson tunnel junctions. This observation marked the birth of the SQUID--Superconducting QUantum Interference Device. The following year saw the appearance of the SLUG (Superconducting Low-inductance Undulatory Galvanometer)--a blob of solder frozen around a length of niobium wire--that was used as a voltmeter with femtovolt resolution. Although extremely primitive by today's standards, the SLUG was used successfully in a number of ultrasensitive experiments. Today, the square washer dc SQUID, fabricated on a wafer-scale from thin films with an integrated input coil, finds a wide range of applications. One example is the use of a SQUID amplifier to read out ADMX--Axion Dark Matter eXperiment--at the University of Washington, Seattle. This experiment, which involves a cooled microwave cavity surrounded by a superconducting magnet, searches for the axion, a candidate for cold dark matter. In the presence of a magnetic field the axion is predicted to decay into a photon, which is detected by the SQUID. In another example, the combination of a SQUID with prepolarized proton spins enables one to perform magnetic resonance imaging (MRI) in magnetic fields of the order of 0.1 mT, four orders of magnitude lower than in conventional MRI systems. In vivo images of the human brain acquired at these ultralow fields are able distinguish brain tissue, blood, cerebrospinal fluid and scalp fat using a combination of inversion recovery and multiple echo sequences. Potential clinical applications are briefly discussed.

  5. The Microwave SQUID Multiplexer

    NASA Astrophysics Data System (ADS)

    Mates, John Arthur Benson

    2011-12-01

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

  6. Dissect Your Squid and Eat It Too!

    ERIC Educational Resources Information Center

    McGinnis, Patricia

    2001-01-01

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

  7. 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.

  8. Time-division SQUID multiplexers

    NASA Astrophysics Data System (ADS)

    Irwin, K. D.; Vale, L. R.; Bergren, N. E.; Deiker, S.; Grossman, E. N.; Hilton, G. C.; Nam, S. W.; Reintsema, C. D.; Rudman, D. A.; Huber, M. E.

    2002-02-01

    SQUID multiplexers make it possible to build arrays of thousands of low-temperature bolometers and microcalorimeters based on superconducting transition-edge sensors with a manageable number of readout channels. We discuss the technical tradeoffs between proposed time-division multiplexer and frequency-division multiplexer schemes and motivate our choice of time division. Our first-generation SQUID multiplexer is now in use in an astronomical instrument. We describe our second-generation SQUID multiplexer, which is based on a new architecture that significantly reduces the dissipation of power at the first stage, allowing thousands of SQUIDs to be operated at the base temperature of a cryostat. .

  9. Rogue mantle helium and neon.

    PubMed

    Albarède, Francis

    2008-02-15

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

  10. 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.

  11. Demonstrating Fluorescence with Neon Paper and Plastic

    ERIC Educational Resources Information Center

    Birriel, Jennifer J.; Roe, Clarissa

    2015-01-01

    Several papers in this journal have dealt with the fluorescence in orange neon plastic, olive oil, and soda. In each case, the fluorescent emission was excited by either green or violet-blue laser light. In this paper, we examine the fluorescent emission spectra of so-called neon colored papers and plastic clipboards available in department and…

  12. Neon Ion Beam Lithography (NIBL).

    PubMed

    Winston, Donald; Manfrinato, Vitor R; Nicaise, Samuel M; Cheong, Lin Lee; Duan, Huigao; Ferranti, David; Marshman, Jeff; McVey, Shawn; Stern, Lewis; Notte, John; Berggren, Karl K

    2011-10-12

    Existing techniques for electron- and ion-beam lithography, routinely employed for nanoscale device fabrication and mask/mold prototyping, do not simultaneously achieve efficient (low fluence) exposure and high resolution. We report lithography using neon ions with fluence <1 ion/nm(2), ∼1000× more efficient than using 30 keV electrons, and resolution down to 7 nm half-pitch. This combination of resolution and exposure efficiency is expected to impact a wide array of fields that are dependent on beam-based lithography. PMID:21899279

  13. 21 CFR 868.1670 - Neon gas analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neon gas analyzer. 868.1670 Section 868.1670 Food... DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1670 Neon gas analyzer. (a) Identification. A neon gas analyzer is a device intended to measure the concentration of neon in a gas mixture exhaled by...

  14. 21 CFR 868.1670 - Neon gas analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neon gas analyzer. 868.1670 Section 868.1670 Food... DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1670 Neon gas analyzer. (a) Identification. A neon gas analyzer is a device intended to measure the concentration of neon in a gas mixture exhaled by...

  15. Small scale demand type neon liquefaction plant

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    Low-temperature measurement of the thermal conductivity of insulating materials is generally made using a boil-off calorimetry technique involving liquid hydrogen (LH2). Liquid neon (LNe) has nearly the same normal boiling point as LH2, but has a much larger heat of vaporization, allowing extended run times. The main drawback of using LNe has been its excessive cost; $170.00 versus $1.50/l for LH2 (1989 prices). A neon liquefaction plant has been designed and constructed to capture, purify, and refrigerate the neon boil-off from calorimetry experiments. Recycling the neon reduces operating costs to approximately $20/l. The system consists of a purification section, a heat exchanger, LNe and LH2 storage dewars, and a fully automated control system. After purification, neon is liquified in the heat exchanger by LH2 flowing countercurrently through stainless steel cooling coils. Hydrogen flow is automatically adjusted to keep the neon at its normal saturation temperature, 27 K. The liquid neon is then stored in a dewar placed directly below the heat exchanger.

  16. Demonstrating Fluorescence with Neon Paper and Plastic

    NASA Astrophysics Data System (ADS)

    Birriel, Jennifer J.; Roe, Clarissa

    2015-09-01

    Several papers in this journal have dealt with the fluorescence in orange neon plastic, olive oil, and soda. In each case, the fluorescent emission was excited by either green or violet-blue laser light. In this paper, we examine the fluorescent emission spectra of so-called neon colored papers and plastic clipboards available in department and office supply stores. We also employ violet-blue and green laser pointers as excitation sources. We conclude with a brief discussion of neon pigments in terms of the "day glow" or "daylight fluorescence" phenomenon.

  17. NEON Citizen Science: Planning and Prototyping

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The National Ecological Observatory Network (NEON) will be a national resource for ecological research and education. NEON citizen science projects are being designed to increase awareness and educate citizen scientists about the impacts of climate change, land-use change, and invasive species on continental-scale ecological processes as well as expand NEON data collection capacity by enabling laypersons to collect geographically distributed data. The citizen science area of the NEON web portal will enable citizen scientists to collect, contribute, interpret, and visualize scientific data, as well as access training modules, collection protocols and targeted learning experiences related to citizen science project topics. For NEON, citizen science projects are a means for interested people to interact with and contribute to NEON science. Investigations at vast spatial and temporal scales often require rapid acquisition of large amounts of data from a geographically distributed population of "human sensors." As a continental-scale ecological observatory, NEON is uniquely positioned to develop strategies to effectively integrate data collected by non-scientists into scientific databases. Ultimately, we plan to work collaboratively to transform the practice of science to include "citizens" or non-scientists in the process. Doing science is not limited to scientists, and breaking down the barriers between scientists and citizens will help people better understand the power of using science in their own decision making. In preparation for fully developing the NEON citizen science program, we are partnering with Project BudBurst (PBB), a citizen science project focused on monitoring plant phenology. The educational goals of PBB are to: (1) increase awareness of climate change, (2) educate citizen scientists about the impacts of climate change on plants and the environment, and (3) increase science literacy by engaging participants in the scientific process. Phenology was

  18. Paleomagnetic Analysis Using SQUID Microscopy

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  19. Recent developments in SQUID NDE

    NASA Astrophysics Data System (ADS)

    Krause, H.-J.; Kreutzbruck, M. v.

    2002-03-01

    By presenting brief summaries of recent application highlights, an overview of NDE methods using SQUIDs is given. Bridge inspection with a SQUID array integrated with a yoke magnet excitation was shown by scanning along the pre-stressed steel of bridges and verified by opening the bridge deck. As the construction of the megaliner Airbus aircraft progresses, testing procedures for extremely thick-walled structures are needed. Defects at a depth of up to 40 mm were measured in a bolted three-layer aluminum sample with a total thickness of 62 mm. For the investigation of aircraft wheels, a remote eddy current (EC) excitation scheme yields better depth selectivity. Defects with an inside penetration of only 10% could be detected. SQUID magnetometers are well suited for pulsed EC techniques which cover a broader depth range than standard single frequency EC. An inversion procedure is presented providing a tomographic-like conductivity image of stacked aluminum samples. A recent SQUID application is nondestructive testing of niobium sheets used for superconducting cavities of particle accelerators. The detection of tantalum inclusions and other impurities which lower the cavity performance is based on the measurement of local current inhomogeneities caused by EC excitation or thermal gradients. Alternate techniques using SQUID sensors, such as modulated excitation arrays, rotating field schemes, sensor multiplexing, magnetic moment detection, and microscopy setups, are discussed.

  20. 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.

  1. 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.

  2. Solar helium and neon in the Earth

    NASA Technical Reports Server (NTRS)

    Honda, M.; Mcdougall, I.; Patterson, D. B.

    1994-01-01

    Neon isotopic compositions in mantle-derived samples commonly are enriched in (20)Ne and (21)Ne relative to (22)Ne compared with atmospheric neon ((20)Ne/(22)Ne and (21)Ne/(22)Ne ratios in atmospheric neon are 9.8 and 0.029, respectively), together with significant primordial (3)He. Such results have been obtained on MORB's, intraplate plume-related oceanic island basalts, backarc basin basalts, mantle xenoliths, ancient diamonds and CO2 well gases (e.g., 1 - 8). The highest (20)Ne/(22)Ne ratio observed in MORB glasses (= 13.6 plus or minus 1.3 is close to the solar value (= 13.6, as observed in solar wind). In order to explain the enrichment of (20)Ne and (21)Ne relative to atmospheric neon for samples derived from the mantle, it is necessary to postulate the presence of at least two distinct non-atmospheric components. The two most likely candidates are solar and nucleogenic ((20)Ne/(22)Ne solar = 13.6 (21)Ne/(22)Ne solar = 0.032, (20)Ne/(22)Ne nucleogenic = 2.5 and (21)Ne/(22)Ne nucleogenic = 32). This is because solar neon is the only known component with a (20)Ne/(22)Ne ratio greater than both the atmospheric value and that observed in samples derived from the mantle. Nucleogenic neon is well known to elevate (21)Ne/(22)Ne ratios. Neon isotopic signatures observed in mantle-derived samples can be accounted for by mixing of the three neon end members: solar, nucleogenic and atmospheric.

  3. Capturing neon - the first experimental structure of neon trapped within a metal-organic environment.

    PubMed

    Wood, Peter A; Sarjeant, Amy A; Yakovenko, Andrey A; Ward, Suzanna C; Groom, Colin R

    2016-08-21

    Despite being the fifth most abundant element in the atmosphere, neon has never been observed in an organic or metal-organic environment. This study shows the adsorption of this highly unreactive element within such an environment and reveals the first crystallographic observation of an interaction between neon and a transition metal. PMID:27452474

  4. NEON Citizen Science: Planning and Prototyping (Invited)

    NASA Astrophysics Data System (ADS)

    Gram, W.

    2010-12-01

    The National Ecological Observatory Network (NEON) will be a national resource for ecological research and education. NEON citizen science projects are being designed to increase awareness and educate citizen scientists about the impacts of climate change, land-use change, and invasive species on continental-scale ecological processes as well as expand NEON data collection capacity by enabling laypersons to collect geographically distributed data. The citizen science area of the NEON web portal will enable citizen scientists to collect, contribute, interpret, and visualize scientific data, as well as access training modules, collection protocols and targeted learning experiences related to citizen science project topics. For NEON, citizen science projects are a means for interested people to interact with and contribute to NEON science. Investigations at vast spatial and temporal scales often require rapid acquisition of large amounts of data from a geographically distributed population of “human sensors.” As a continental-scale ecological observatory, NEON is uniquely positioned to develop strategies to effectively integrate data collected by non-scientists into scientific databases. Ultimately, we plan to work collaboratively to transform the practice of science to include “citizens” or non-scientists in the process. Doing science is not limited to scientists, and breaking down the barriers between scientists and citizens will help people better understand the power of using science in their own decision making. In preparation for fully developing the NEON citizen science program, we are partnering with Project BudBurst (PBB), a citizen science project focused on monitoring plant phenology. The educational goals of PBB are to: (1) increase awareness of climate change, (2) educate citizen scientists about the impacts of climate change on plants and the environment, and (3) increase science literacy by engaging participants in the scientific process

  5. Cold SQUIDs and hot samples

    SciTech Connect

    Lee, T.S.C. |

    1997-05-01

    Low transition temperature (low-{Tc}) and high-{Tc} Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-{Tc} superconductors using two low-{Tc} SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied 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.

  6. How the SQUID was born

    NASA Astrophysics Data System (ADS)

    Silver, Arnold H.

    2006-05-01

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

  7. 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.

  8. Improved Sensing Coils for SQUIDs

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  9. 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.

  10. An X-band SQUID Multiplexer

    NASA Astrophysics Data System (ADS)

    Hahn, I.; Bumble, B.; LeDuc, H. G.; Weilert, M.; Day, P.

    2006-09-01

    We are developing a microwave readout multiplexer for arrays of superconducting quantum interference devices (SQUIDs). A series of microwave resonators with frequencies ˜10 GHz are each loaded by a dc SQUID to a degree that depends on the flux state of the SQUID. By using resonators with high quality factors and slightly different resonance frequencies, many of these resonator-coupled SQUIDs may be read out with a single excitation line and cryogenic amplifier. Our multiplexer is similar to the one demonstrated by Irwin and Lehnert except for the use of higher-frequency, fully-lithographed transmission line resonators. We discuss a technique for modulating the SQUID array in series that alleviates the need to individually flux-bias the SQUIDs. The multiplexer has applications to the readout of detector arrays for astronomy as well as medical magnetic imaging.

  11. The First NEON School in La Silla

    NASA Astrophysics Data System (ADS)

    Dennefeld, M.; Melo, C.; Selman, F.

    2016-06-01

    The NEON Observing Schools have long provided PhD students with practical experience in the preparation, execution and reduction of astronomical observations, primarily at northern observatories. The NEON School was held in Chile for the first time, with observations being conducted at La Silla. The school was attended by 20 students, all from South America, and observations were performed with two telescopes, including the New Technology Telescope. A brief description of the school is presented and the observing projects and their results are described.

  12. Rogue Mantle Helium and Neon

    NASA Astrophysics Data System (ADS)

    Albarede, F.

    2007-12-01

    mid- ocean ridges, the characteristic times of melt extraction in each of these two environments are 10,000 y and 1 My, respectively, and the maximum thickness of refractory layers contributing their He to the magmas are 10 m and 100 m, respectively. The difference in 3He/4He ratios of ocean-island and mid-ocean ridge basalts and the preservation of solar neon are ascribed to the reservoirs rocks being stretched to a different extent during melting. Old fragments of oceanic lithosphere, and possibly cumulates from the magma ocean, rather than primordial mantle 'nuggets', should host most of the primordial He and Ne presently observed in oceanic basalts. Helium with high 3He/4He ratios may contain a component of primordial origin, but not necessarily reflect the reservoir in which it has been residing for most of the Earth's history.

  13. Analytical derivation of DC SQUID response

    NASA Astrophysics Data System (ADS)

    Soloviev, I. I.; Klenov, N. V.; Schegolev, A. E.; Bakurskiy, S. V.; Kupriyanov, M. Yu

    2016-09-01

    We consider voltage and current response formation in DC superconducting quantum interference device (SQUID) with overdamped Josephson junctions in resistive and superconducting state in the context of a resistively shunted junction (RSJ) model. For simplicity we neglect the junction capacitance and the noise effect. Explicit expressions for the responses in resistive state were obtained for a SQUID which is symmetrical with respect to bias current injection point. Normalized SQUID inductance l=2{{eI}}{{c}}L/{\\hslash } (where I c is the critical current of Josephson junction, L is the SQUID inductance, e is the electron charge and ℏ is the Planck constant) was assumed to be within the range l ≤ 1, subsequently expanded up to l≈ 7 using two fitting parameters. SQUID current response in the superconducting state was considered for arbitrary value of the inductance. The impact of small technological spread of parameters relevant to low-temperature superconductor (LTS) technology was studied, using a generalization of the developed analytical approach, for the case of a small difference of critical currents and shunt resistances of the Josephson junctions, and inequality of SQUID inductive shoulders for both resistive and superconducting states. Comparison with numerical calculation results shows that developed analytical expressions can be used in practical LTS SQUIDs and SQUID-based circuits design, e.g. large serial SQIF, drastically decreasing the time of simulation.

  14. Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

    PubMed Central

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

    2015-01-01

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

  15. SQUID Multiplexers for Cryogenic Detector Arrays

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  16. Low field electron paramagnetic resonance imaging with SQUID detection

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  17. 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

  18. Genetic identification of a rare record of Ommastrephes Bartramii (Cephalopoda: Ommastrephidae) from the Eastern Adriatic Sea.

    PubMed

    Franjević, Damjan; Skaramuca, Daria; Katavić, Vedran; Rajević, Nives; Skaramuca, Boško

    2015-01-01

    The neon flying squid Ommastrephes bartramii Lesueur, 1821 belongs to the Ommastrephidae, Cephalopoda family. The family Ommastrephidae (Mollusca: Cephalopoda) includes many commercially important species, dispersed around the world. The Ommastrephidae family is conventionally divided into three subfamilies (Illicinae, Todarodinae, and Ommastrephinae). We report a specimen of neon flying squid caught in the winter 2013 at Luka Šipanska, Island of Šipan, Croatia and identified at the genetic level using the standard mitochondrial COI barcode region. This record represents the first genetic identification of a neon flying squid from the Adriatic Sea. PMID:26103681

  19. Nanofriction of neon films on superconducting lead.

    PubMed

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

    2010-07-01

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

  20. The NEON Soil Archive - A community resource

    NASA Astrophysics Data System (ADS)

    Ayres, E.

    2013-12-01

    The National Ecological Observatory Network (NEON) is a 30-year National Science Foundation-funded facility for understanding and forecasting the impacts of climate change, land use change, and invasive species on aspects of continental-scale ecology such as biodiversity, biogeochemistry, infectious diseases, and ecohydrology. NEON will measure a wide range of properties at 60 terrestrial and 36 aquatic sites throughout the US using in situ sensors, sample collection/lab analysis, and remote sensing, and all data will be made freely available. The Observatory is currently under construction and will be fully operational by 2017, however, limited data collection and release will begin in 2013. In addition, NEON is archiving large numbers of samples, including surface soils (top ~30 cm) collected from locations across each site, and soils collected by horizon to 2 m deep from a single soil pit at each site. Here I present information about the latter, focusing on sampling and processing, metadata, and currently available samples. At each terrestrial site the soil pit is dug in the locally dominant soil type and soil is collected by horizon, mixed, and ~4-8 liters soil is sent for processing. Soil samples are air-dried and sieved (mineral soil) or air-dried (organic soil) and 1.2 kg is split between 4 glass jars for archiving (protocol available upon request). To date 15 soil pits have been sampled, representing 7 soil orders, and soils from 110 horizons have been archived or are being processed. Metadata associated with each archive sample include a soil profile description, photos, and soil properties (total C, N, S, Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Sr, Ti, Zr, bulk density, pH, and texture). The procedure for requesting samples from the archive is under development and I encourage scientists to use the archive in their future research. Collecting and processing samples for the NEON Soil Archive

  1. 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

  2. First demonstration of transcontinental SQUID magnetometry (Invited)

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  3. 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.

  4. Muon transfer from hot muonic hydrogen atoms to neon

    SciTech Connect

    Jacot-Guillarmod, R. . Inst. de Physique); Bailey, J.M. ); Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A. ); Beveridge, J.L.; Marshall, G.M.; Brewer, J.H.; Forster, B.M. ); Huber, T.M. ); Kammel, P.; Zmeskal, J.

    1992-01-01

    A negative muon beam has been directed on adjacent solid layers of hydrogen and neon. Three targets differing by their deuterium concentration were investigated. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. The time structure of the muonic neon X-rays follows the exponential law with a disappearance rate corresponding to the one of [mu][sup [minus]p] atoms in each target. The rates [lambda][sub pp[mu

  5. Structural and magnetic properties of zinc ferrite thin films irradiated by 90 keV neon ions

    NASA Astrophysics Data System (ADS)

    Gafton, E. V.; Bulai, G.; Caltun, O. F.; Cervera, S.; Macé, S.; Trassinelli, M.; Steydli, S.; Vernhet, D.

    2016-08-01

    The effects of 90 keV neon beam irradiation on the structure and magnetic properties of zinc ferrite thin films have been investigated through several methods, namely, X-ray diffraction technique, Vibrating Sample and SQUID magnetometers. Beforehand, the pristine have also been characterized using profilometry and microscopy techniques. In particular single-phase formation of the thin films deposited on monocrystalline Si (111) substrate by pulsed laser deposition technique was confirmed. Crystal lattice, coercivity, saturation magnetization have been studied for the first time, as a function of ion penetration depth and irradiation fluence. The chemical composition and the crystallinity of the films are not affected with the ion impact acting as a mechanical stress relief. On the contrary, both magnetization and coercivity are sensitive to Neq+ ion irradiation and exhibit different behaviours depending on the ion fluence range.

  6. 21 CFR 868.1670 - Neon gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neon gas analyzer. 868.1670 Section 868.1670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1670 Neon gas analyzer. (a) Identification. A...

  7. 21 CFR 868.1670 - Neon gas analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neon gas analyzer. 868.1670 Section 868.1670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1670 Neon gas analyzer. (a) Identification. A...

  8. 21 CFR 868.1670 - Neon gas analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neon gas analyzer. 868.1670 Section 868.1670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1670 Neon gas analyzer. (a) Identification. A...

  9. Dietary protein source and level alters growth in neon tetras.

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Scattering of electrons from neon atoms

    NASA Technical Reports Server (NTRS)

    Dasgupta, A.; Bhatia, A. K.

    1984-01-01

    Scattering of electrons from neon atoms is investigated by the polarized-orbital method. The perturbed orbitals calculated with use of the Sternheimer approximation lead to the polarizability 2.803 a(0)-cube in fairly good agreement with the experimental value 2.66 a(0)-cube. Phase shifts for various partial waves are calculated in the exchange, exchange-adiabatic, and polarized-orbital approximations. They are compared with the previous results. The calculated elastic differential, total, and momentum-transfer cross sections are compared with the experimental results. The polarized-orbital approximation yields results which show general improvement over the exchange-adiabatic approximation.

  11. 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 Γ> 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 Γ). 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

  12. Electron-impact excitation of neon

    NASA Astrophysics Data System (ADS)

    Ballance, Connor; Griffin, Don

    2004-05-01

    A number of convergent close-coupling and R-matrix with pseudo-state (RMPS) calculations on H-like, He-like, Li-like, and Be-like ions have demonstrated that coupling to the target continuum can have large effects on the electron-impact excitation cross sections of neutral and low-charge species. However, no one has yet attempted such advanced calculations on a system as complex as neutral neon. We report on a series of RMPS calculations of electron-impact excitation of Ne using recently developed parallel Breit-Pauli (BP) R-matrix programs. Our largest calculation was a BP calculation with 235 spectroscopic and pseudo levels in the close-coupling expansion. Although the results of this calculation clearly reveal the importance of coupling to the target continuum in this atom, the pseudo-state expansion is not yet sufficiently complete to provide reliable cross sections for energies above the ionization limit. However, this is the largest BP calculation that can be performed with present computer resources. Thus, we have also carried out a series of RMPS calculations in LS coupling with different pseudo-state expansions. Comparisons of these results have allowed us to determine the approximate size of the pseudo-state expansion required to achieve convergence in future BP calculations for neon.

  13. Coherence parameter measurements for neon and hydrogen

    NASA Astrophysics Data System (ADS)

    Wright, Robert; Hargreaves, Leigh; Khakoo, Murtadha; Zatsarinny, Oleg; Bartschat, Klaus; Stauffer, Al

    2015-09-01

    We present recent coherence parameter measurements for excitation of neon and hydrogen by 50 eV electrons. The measurements were made using a crossed electron/gas beam spectrometer, featuring a hemispherically selected electron energy analyzer for detecting scattered electrons and double-reflection VUV polarization analyzer to register fluorescence photons. Time-coincidence counting methods on the electron and photon signals were employed to determine Stokes Parameters at each scattering angle, with data measured at angles between 20 - 115 degrees. The data are compared with calculated results using the B-Spline R-Matrix (BSR) and Relativistic Distorted Wave (RDW) approaches. Measurements were made of both the linear (Plin and γ) and circular (Lperp) parameters for the lowest lying excited states in these two targets. We particularly focus on results in the Lperp parameter, which shows unusual behavior in these particular targets, including strong sign changes implying reversal of the angular momentum transfer. In the case of neon, the unusual behavior is well captured by the BSR, but not by other models.

  14. Flying Cars

    NASA Technical Reports Server (NTRS)

    Crow, Steven

    1996-01-01

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

  15. Visually guided eye growth in the squid.

    PubMed

    Turnbull, Philip R K; Backhouse, Simon; Phillips, John R

    2015-09-21

    Eyes with refractive error have reduced visual acuity and are rarely found in the wild. Vertebrate eyes possess a visually guided emmetropisation process within the retina which detects the sign of defocus, and regulates eye growth to align the retina at the focal plane of the eye's optical components to avoid the development of refractive error, such as myopia, an increasing problem in humans. However, the vertebrate retina is complex, and it is not known which of the many classes of retinal neurons are involved. We investigated whether the camera-type eye of an invertebrate, the squid, displays visually guided emmetropisation, despite squid eyes having a simple photoreceptor-only retina. We exploited inherent longitudinal chromatic aberration (LCA) to create disparate focal lengths within squid eyes. We found that squid raised under orange light had proportionately longer eyes and more myopic refractions than those raised under blue light, and when switched between wavelengths, eye size and refractive status changed appropriately within a few days. This demonstrates that squid eye growth is visually guided, and suggests that the complex retina seen in vertebrates may not be required for emmetropisation. PMID:26394098

  16. Squid – a simple bioinformatics grid

    PubMed Central

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

    2005-01-01

    Background BLAST is a widely used genetic research tool for analysis of similarity between nucleotide and protein sequences. This paper presents a software application entitled "Squid" that makes use of grid technology. The current version, as an example, is configured for BLAST applications, but adaptation for other computing intensive repetitive tasks can be easily accomplished in the open source version. This enables the allocation of remote resources to perform distributed computing, making large BLAST queries viable without the need of high-end computers. Results Most distributed computing / grid solutions have complex installation procedures requiring a computer specialist, or have limitations regarding operating systems. Squid is a multi-platform, open-source program designed to "keep things simple" while offering high-end computing power for large scale applications. Squid also has an efficient fault tolerance and crash recovery system against data loss, being able to re-route jobs upon node failure and recover even if the master machine fails. Our results show that a Squid application, working with N nodes and proper network resources, can process BLAST queries almost N times faster than if working with only one computer. Conclusion Squid offers high-end computing, even for the non-specialist, and is freely available at the project web site. Its open-source and binary Windows distributions contain detailed instructions and a "plug-n-play" instalation containing a pre-configured example. PMID:16078998

  17. Flux modulation scheme for direct current SQUID readout revisited

    NASA Astrophysics Data System (ADS)

    Hong, Tao; Wang, Hai; Zhang, Yi; Krause, Hans-Joachim; Braginski, Alex I.; Xie, Xiaoming; Offenhäusser, Andreas; Jiang, Mianheng

    2016-02-01

    The flux modulation scheme (FMS) is the standard readout technique of dc SQUIDs, where a step-up transformer links the SQUID to the preamplifier. The transformer's primary winding shunts the SQUID via a large capacitor while the secondary winding connects it to the preamplifier. A modulation flux having a frequency of typically 100 kHz generates an ac voltage across the SQUID, stepped up by the transformer. The SQUID with FMS is customarily operated in the current bias mode, because a constant dc bias current flows only through the SQUID due to the capacitor isolation. With FMS, however, the transformer ac shunts the SQUID so that in reality the operating mode is neither purely current-biased nor voltage-biased but rather nominal current-biased or "mixed biased." Our objective is to experimentally investigate the consequences of ac shunting of the dc SQUID in FMS and the transformer's transfer characteristics. For different shunt values we measure the change in the SQUID bias current due to the ac shunt using another SQUID in the two-stage readout scheme, and simultaneously monitor the SQUID output voltage signal. We then explain our measurements by a simplified graphic analysis of SQUID intrinsic current-voltage (I-V) characteristics. Since the total current flowing through the SQUID is not constant due to the shunting effect of the transformer, the amplitude of SQUID flux-to-voltage characteristics V(Φ) is less as compared to the direct readout scheme (DRS). Furthermore, we analyze and compare V(Φ) obtained by DRS and FMS. We show that in FMS, the transfer characteristics of the SQUID circuit also depend on the isolation capacitance and the dynamic resistance of the SQUID.

  18. A neon-E rich phase in Orgueil - Results obtained on density separates

    NASA Astrophysics Data System (ADS)

    Eberhardt, P.; Jungck, M. H. A.; Meier, F. O.; Niederer, F. R.

    1981-09-01

    A stepwise heating technique was used on eight density separates from the neon-E rich phase G4j of the carbonaceous chondrite Orgueil to measure He, Ne and Ar. The density separation technique was found to further enrich the Ne-E carrier phases, allowing the Ne-E to be identified as virtually pure Ne-22. At least two separable carrier phases exist: (1) the l-carrier phase, which releases its Ne-E at temperatures below 900 C and is heavily enriched in the low-density separate; and (2) the h-carrier phase. The h-carrier is found to be highly retentive, with release temperatures above 900 C, and is associated with higher-density material. It is concluded that Ne-E and its carrier phases are probably of presolar origin.

  19. SQUID method of lung contamination testing

    NASA Astrophysics Data System (ADS)

    Martinická, F.; Šimáček, I.; Jurdák, P.; Cigáň, A.; Maňka, J.

    2006-03-01

    We are reporting on the development of a SQUID magnetometric method of ferromagnetic dust quantification in the human lungs. In order to solve this problem we utilize a forward method of magnetized ferromagnetic particle (dipole) distribution 3D modeling in human lung torso and in an arc welder's lungs. We also solve the inverse problem, by which the amount of dust in the lungs is estimated using the results of the remanent magnetic induction Br measurement upon the human chest. We state the formula for SQUID measured output voltage U to Br conversion for the second order gradiometer, which is in a highly dipole position and density dependent. We utilize a low-Tc second order rf SQUID gradiometer with the sensitivity of 10-14 T in the unit frequency range.

  20. The prospects of a subnanometer focused neon ion beam.

    PubMed

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

    2012-01-01

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

  1. Comprehensive Testing of a Neon Cryogenic Capillary Pumped Loop

    NASA Technical Reports Server (NTRS)

    Kobel, Mark C.; Ku, Jentung; Obenschain, Arthur F. (Technical Monitor)

    2001-01-01

    This paper describes a comprehensive test program of a cryogenic capillary pumped loop (CCPL) using neon as the working fluid in the temperature range between 30 K and 40 K. The test article was originally designed to be used with nitrogen in the 70 K to 100 K temperature range, and was refurbished for testing with neon. Tests performed included start up from a supercritical state, power cycle, sink temperature cycle, heat transport limit, low power limit, reservoir set point change and long duration operation. The neon CCPL has demonstrated excellent performance under various conditions.

  2. The NEON School Enters a New Era

    NASA Astrophysics Data System (ADS)

    Dennefeld, M.

    2004-12-01

    THE NEON SCHOOL, a school on astronomical observations organised by a collaboration of observatories (Asiago, Calar Alto, ESO, La Palma and OHP) is well known by PhD students in astronomy all over Europe. It runs tutorial observations directly at the telescope for students in small groups, under the supervision of an experienced astronomer. This way, the participants can execute a real scientific program with all the steps needed in professional life: preparation of the program with selection of targets and feasibility estimates; set-up of the instrument and calibrations; running of the observations, in general both imaging/photometry and spectroscopy; data reductions; and, finally, the presentation of the results at the end of the school.

  3. Neon and Oxygen Abundances in M33

    NASA Astrophysics Data System (ADS)

    Crockett, Nathan R.; Garnett, Donald R.; Massey, Philip; Jacoby, George

    2006-02-01

    We present new spectroscopic observations of 13 H II regions in the Local Group spiral galaxy M33. The regions observed range from 1 to 7 kpc in distance from the nucleus. Of the 13 H II regions observed, the [O III] λ4363 line was detected in six regions. Electron temperatures were thus able to be determined directly from the spectra using the [O III] λλ4959, 5007/λ4363 line ratio. Based on these temperature measurements, oxygen and neon abundances and their radial gradients were calculated. For neon, a gradient of -0.016+/-0.017 dex kpc-1 was computed, which agrees with the Ne/H gradient derived previously from ISO spectra. A gradient of -0.012+/-0.011 dex kpc-1 was computed for O/H, much shallower than was derived in previous studies. The newly calculated O/H and Ne/H gradients are in much better agreement with each other, as expected from predictions of stellar nucleosynthesis. We examine the correlation between the WC/WN ratio and metallicity, and find that the new M33 abundances do not impact the observed correlation significantly. We also identify two new He II-emitting H II regions in M33, the first to be discovered in a spiral galaxy other than the Milky Way. In both cases the nebular He II emission is not associated with Wolf-Rayet stars. Therefore, caution is warranted in interpreting the relationship between nebular He II emission and Wolf-Rayet stars when both are observed in the integrated spectrum of an H II region.

  4. A Three-Channel DC SQUID System Using Time-Domain Multiplexing

    NASA Astrophysics Data System (ADS)

    Korn, Matthias; Mueck, Michael; Mugford, Chas; Kycia, Jan

    2004-03-01

    Conventional multichannel SQUID systems require SQUID readout electronics for each channel, as well as many wires connecting the individual SQUIDs and feedback coils to the room temperature electronics. We have studied a time domain multiplexed readout scheme which requires only a single SQUID readout which is successively switched between all SQUIDs. By connecting all SQUIDs and all feedback coils in series, the system requires only a few wires between SQUIDs and room temperature readout.

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

    NASA Astrophysics Data System (ADS)

    Tabatabaei, Mahdi; Bahadır 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.

  6. 4.2K Cryocooled Scanning SQUID Microscope

    NASA Astrophysics Data System (ADS)

    Kwon, S. P.; Knauss, L.; Lettsome, N.; Cawthorne, A.; Lobb, C. J.; Wellstood, F. C.

    2003-03-01

    We have assembled a scanning SQUID microscope using a Nb SQUID and a cryocooler. The Nb SQUID is contained within a vacuum jacket while material being scanned is at room temperature and normal atmospheric pressure. A 25 micron thick sapphire window separates the SQUID in vacuum from the scanned material. The Nb DC SQUID, fabricated by Hypres Inc., has an inner dimension of 10 microns by 10 microns and the Josephson Junctions are resistively shunted. Cooling is provided by a Pulse Tube Cryocooler from Cryomech Inc. Temperatures as low as 3.8 K have been obtained while operating the SQUID microscope. Due to radiation heating, the temperature of the SQUID has been estimated to be 1.0 K to 1.5 K higher than sensor values. Flux-Locked-Loop electronics are used to take magnetic field data. Preliminary measurements of the flux noise indicated resolution to better than 10 micro Flux Quantum for one second averaging time.

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

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

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

  8. One Period of Exploration with the Squid.

    ERIC Educational Resources Information Center

    Bradley, James V.; Ng, Andrew

    1997-01-01

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

  9. Squid Dissection: From Pen to Ink.

    ERIC Educational Resources Information Center

    Brown, Cindy; Kisiel, Jim

    2003-01-01

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

  10. 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. . Low Temperature Lab.); Tesche, C.D. . 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.

  11. High Resolution LTS-SQUID Microscopes

    NASA Astrophysics Data System (ADS)

    Baudenbacher, Franz; Peters, Nicholas; Wikswo, John

    2000-03-01

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

  12. TOPICAL REVIEW: SQUID systems for biomagnetic imaging

    NASA Astrophysics Data System (ADS)

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

    2001-07-01

    This review paper illustrates the different SQUID based systems used for biomagnetic imaging. The review is divided into nine sections. The first three sections are introductory: section 1 is a short overview of the topic; section 2 summarizes how the biomagnetic fields are generated and what are the basic mathematical models for the field sources; section 3 illustrates the principles of operation of the SQUID device. Sections 4-8 are specifically devoted to the description of the different systems used for biomagnetic measurements: section 4 discusses the different types of detection coils; section 5 illustrates the SQUID sensors specifically designed for biomagnetic applications together with the necessary driving electronics, with special emphasis on high-temperature superconductivity (HTS) SQUIDs, since HTS devices are still in a developing stage; section 6 illustrates the different noise reduction techniques; section 7 describes the different multichannel sensors presently operating; and, finally, section 8 gives a hint of what kind of physiological and/or clinical information may be gathered by the biomagnetic technique. Section 9 suggests some future trends for the biomagnetic technique.

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

    PubMed

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

    2015-01-15

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

  14. Superconducting Nanobridge SQUID Magnetometers for Spin Sensing

    NASA Astrophysics Data System (ADS)

    Antler, Natania

    As the cutting edge of science and technology pushes towards smaller length scales, sensing technologies with nanoscale precision become increasingly important. In this thesis I will discuss the optimization and application of a 3D nanobridge SQUID magnetometer for studying solid state spin systems, in particular for sensing impurity spins in diamond. Solid state spins have proposed applications in memory and computation for both classical and quantum computing. Isolated spins typically have longer coherence times, making them attractive qubit candidates, but necessitating the development of very sensitive detectors for readout. This 3D nanobridge SQUID combines the exquisite spatial sensitivity of a traditional nanoSQUID with a large non-linearity on par with a tunnel junction SQUID. This allows us to build a highly sensitive magnetometer which can act as both an efficient flux transducer as well as a nearly quantum limited lumped Josephson Parametric Amplifier. We show that the device has a minimum flux noise of 17 +/- 0.9 nphi0/Hz1/2 with only a factor of ˜2.5 increase in flux noise up to 61 mT. A second generation device with a smaller capacitor achieves field tolerance up to 75 mT. The maximal bandwidth values range from 25-40 MHz in the parametric amplification regime to 70 MHz in the linear regime. This combination of large bandwidth, low flux noise, large flux coupling and field tolerance make this sensor a promising candidate for near-single-spin dynamics measurements. In the last part of this thesis we begin to demonstrate the utility of a nanobridge SQUID magnetometer for characterizing spin systems in the solid state. We use the magnetometer to measure the decay characteristics of P1 centers in diamond. We find that the spin-lattice relaxation time varies with temperature, with an order of magnitude decrease in the decay time between 25 mK and 370 mK.

  15. Light-curve Analysis of Neon Novae

    NASA Astrophysics Data System (ADS)

    Hachisu, Izumi; Kato, Mariko

    2016-01-01

    We analyzed light curves of five neon novae, QU Vul, V351 Pup, V382 Vel, V693 CrA, and V1974 Cyg, and determined their white dwarf (WD) masses and distance moduli on the basis of theoretical light curves composed of free-free and photospheric emission. For QU Vul, we obtained a distance of d ˜ 2.4 kpc, reddening of E(B - V) ˜ 0.55, and WD mass of MWD = 0.82-0.96 {M}⊙ . This suggests that an oxygen-neon WD lost a mass of more than ˜ 0.1 {M}⊙ since its birth. For V351 Pup, we obtained d˜ 5.5 {{kpc}}, E(B-V)˜ 0.45, and {M}{{WD}}=0.98-1.1 {M}⊙ . For V382 Vel, we obtained d˜ 1.6 {{kpc}}, E(B-V)˜ 0.15, and {M}{{WD}}=1.13-1.28 {M}⊙ . For V693 CrA, we obtained d˜ 7.1 {{kpc}}, E(B-V)˜ 0.05, and {M}{{WD}}=1.15-1.25 {M}⊙ . For V1974 Cyg, we obtained d˜ 1.8 {{kpc}}, E(B-V)˜ 0.30, and {M}{{WD}}=0.95-1.1 {M}⊙ . For comparison, we added the carbon-oxygen nova V1668 Cyg to our analysis and obtained d˜ 5.4 {{kpc}}, E(B-V)˜ 0.30, and {M}{{WD}}=0.98-1.1 {M}⊙ . In QU Vul, photospheric emission contributes 0.4-0.8 mag at most to the optical light curve compared with free-free emission only. In V351 Pup and V1974 Cyg, photospheric emission contributes very little (0.2-0.4 mag at most) to the optical light curve. In V382 Vel and V693 CrA, free-free emission dominates the continuum spectra, and photospheric emission does not contribute to the optical magnitudes. We also discuss the maximum magnitude versus rate of decline relation for these novae based on the universal decline law.

  16. High-Tc and low-Tc dc SQUID electronics

    NASA Astrophysics Data System (ADS)

    Drung, Dietmar

    2003-12-01

    Superconducting quantum interference devices (SQUIDs) are commonly operated in a flux-locked loop (FLL). The SQUID electronics amplifies the small SQUID signal to an acceptable level without adding noise, and it linearizes the transfer function of the SQUID in order to provide sufficient dynamic range. In this paper, the fundamentals of SQUID readout are reviewed including a discussion of preamplifier noise. The basic FLL concepts, direct readout and flux modulation readout, are discussed both with dc bias and bias reversal. Alternative readout concepts such as additional positive feedback (APF), two-stage SQUIDs, SQUID series arrays, relaxation oscillation SQUIDs and digital SQUIDs are briefly described. The FLL dynamics are discussed on the basis of a simple model with finite loop delay. It is shown that with optimized SQUID electronics a system bandwidth of ap18 MHz and a corresponding slew rate of ap8 PHgr0 µs-1 are possible. A novel FLL scheme involving a Smith predictor is presented which allows one to increase the FLL bandwidth to about 100 MHz. The theoretical predictions are experimentally checked using a high-speed SQUID electronics prototype with a small-signal bandwidth of 300 MHz. Methods for increasing the dynamic range of SQUID systems are described: flux-quanta counting and dynamic field compensation (DFC). With DFC, the residual magnetic field at the SQUID can be kept close to zero even if the device is moved in the Earth's field. Therefore, the noise level of a high-Tc magnetometer measured inside a magnetically shielded room (60 fT Hz-1/2 with a 1/f corner at 2 Hz) remained unchanged after moving the device in the magnetic field outside the room (60 µT dc plus 0.8 µT peak-to-peak power line interference).

  17. Laying the groundwork for NEON's continental-scale ecological research

    NASA Astrophysics Data System (ADS)

    Dethloff, G.; Denslow, M.

    2013-12-01

    The National Ecological Observatory Network (NEON) is designed to examine a suite of ecological issues. Field-collected data from 96 terrestrial and aquatic sites across the U.S. will be combined with remotely sensed data and existing continental-scale data sets. Field collections will include a range of physical and biological types, including soil, sediment, surface water, groundwater, precipitation, plants, animals, insects, and microbes as well as biological sub-samples such as leaf material, blood and tissue samples, and DNA extracts. Initial data analyses and identifications of approximately 175,000 samples per year will occur at numerous external laboratories when all sites are fully staffed in 2017. Additionally, NEON will archive biotic and abiotic specimens at collections facilities where they will be curated and available for additional analyses by the scientific community. The number of archived specimens is currently estimated to exceed 130,000 per year by 2017. We will detail how NEON is addressing the complexities and challenges around this set of analyses and specimens and how the resulting high-quality data can impact ecological understanding. The raw data returned from external laboratories that is quality checked and served by NEON will be the foundation for many NEON data products. For example, sequence-quality nucleic acids extracted from surface waters, benthic biofilms, and soil samples will be building blocks for data products on microbial diversity. The raw sequence data will also be available for uses such as evolutionary investigations, and the extracts will be archived so others can acquire them for additional research. Currently, NEON is establishing contracts for the analysis and archiving of field-collected samples through 2017. During this period, NEON will gather information on the progress and success of this large-scale effort in order to determine the most effective course to pursue with external facilities. Two areas that NEON

  18. 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

    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.

  19. Graphene engineering by neon ion beams

    DOE PAGESBeta

    Iberi, Vighter; Ievlev, Anton V.; Vlassiouk, Ivan; Jesse, Stephen; Kalinin, Sergei V.; Joy, David C.; Rondinone, Adam J.; Belianinov, Alex; Ovchinnikova, Olga S.

    2016-02-18

    Achieving the ultimate limits of materials and device performance necessitates the engineering of matter with atomic, molecular, and mesoscale fidelity. While common for organic and macromolecular chemistry, these capabilities are virtually absent for 2D materials. In contrast to the undesired effect of ion implantation from focused ion beam (FIB) lithography with gallium ions, and proximity effects in standard e-beam lithography techniques, the shorter mean free path and interaction volumes of helium and neon ions offer a new route for clean, resist free nanofabrication. Furthermore, with the advent of scanning helium ion microscopy, maskless He+ and Ne+ beam lithography of graphenemore » based nanoelectronics is coming to the forefront. Here, we will discuss the use of energetic Ne ions in engineering graphene devices and explore the mechanical, electromechanical and chemical properties of the ion-milled devices using scanning probe microscopy (SPM). By using SPM-based techniques such as band excitation (BE) force modulation microscopy, Kelvin probe force microscopy (KPFM) and Raman spectroscopy, we demonstrate that the mechanical, electrical and optical properties of the exact same devices can be quantitatively extracted. Additionally, the effect of defects inherent in ion beam direct-write lithography, on the overall performance of the fabricated devices is elucidated.« less

  20. Multistage Zeeman deceleration of metastable neon.

    PubMed

    Wiederkehr, Alex W; Motsch, Michael; Hogan, Stephen D; Andrist, Markus; Schmutz, Hansjürg; Lambillotte, Bruno; Agner, Josef A; Merkt, Frédéric

    2011-12-01

    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 (20)Ne and (22)Ne. PMID:22149785

  1. Search for Metastability of 2s Muonic Neon

    NASA Astrophysics Data System (ADS)

    Bach, Bernard Wilhelm

    1995-01-01

    An experiment was performed at the Paul Scherrer Institut (PSI) to establish the conditions for the metastability of the 2S-state of muonic neon. The muonic atoms were formed by stopping negative muons in the neon-filled target chamber of the PSI cyclotron trap. A pair of intrinsic germanium detectors were used in coincidence to search for the two photon decay of the 2S-state. Both energy and time information from two photon events were written to disk for off-line analysis. Data were accumulated for neon pressures of 40 and 400 Torr. The data were then searched for evidence of two photon transitions from the 2S-state. The germanium detectors were sensitive to the K-, L- and M- series x-ray photons (with energies between 10 and 300 keV) emitted during the cascade of the muonic neon ion. The detectors were also used alone to record single photon events of the K- and L-series x rays. The observed intensity ratios of the K-series x rays provided a lower limit on the initial population of the 2S-state. For the pressure condition of 40 Torr of neon, the 2S population was found to be 1.75% +/- .15% of the total cascade. The number of events at 40 Torr that could be attributed to two photon decays of the 2S-state was found to be 30 +/- 52 corresponding to a 2S population of 3.8% +/- 6.5%. At 400 Torr of neon the observed number of 2S two photon decays was 7 +/- 41, placing an upper limit on the 2S population at 0.9% +/- 5.1% of the total cascade. These results, to within the experimental uncertainties, can neither establish nor exclude the metastability of 2S muonic neon.

  2. A method for simulating a flux-locked DC SQUID

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  3. Coupled Serial and Parallel Non-uniform SQUIDs

    SciTech Connect

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

    2011-04-19

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

  4. Practical SQUID Instrument for Nondestructive Testing

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  5. Low Temperature SQUID for NDE Applications

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz (Technical Monitor); Selim, Raouf

    2003-01-01

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

  6. Supersensitive SQUID/magnetostrictor detecting system

    SciTech Connect

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

    2012-12-31

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

  7. Practical SQUID instrument for nondestructive testing

    SciTech Connect

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

    1997-09-01

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

  8. Multichannel applications of double relaxation oscillation SQUIDs

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Ho; Kwon, Hyukchan; Kim, Jin-Mok; Park, Yong-Ki

    2001-12-01

    Double relaxation oscillation SQUIDs (DROSs) provided high flux-to-voltage transfers of larger than 1 mV Φ0-1 and simple flux-locked loop circuits were used for SQUID operation. We constructed two multichannel systems based on DROSs. The first system is a 40-channel planar gradiometer system consisting of integrated first-order pickup coils. average noise level of the 40 channels is 1 fT cm-1 Hz-1/2 at 100 Hz, corresponding to a field noise of 4 fT Hz-1/2, operating inside a magnetically shielded room. The second one is a 37-channel magnetometer system with 37 integrated magnetometers distributed on a spherical surface and measures field component normal to the head surface. The average noise of the magnetometers is 3 fT Hz-1/2 at 100 Hz. The two systems were applied to measure neuromagnetic fields.

  9. Investigation of noise sources in SQUID electronics

    SciTech Connect

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

    1989-03-01

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

  10. Performance of multiplexed SQUID readout for Cryogenic Sensor Arrays

    NASA Astrophysics Data System (ADS)

    Chervenak, J. A.; Grossman, E. N.; Irwin, K. D.; Martinis, John M.; Reintsema, C. D.; Allen, C. A.; Bergman, D. I.; Moseley, S. H.; Shafer, R.

    2000-04-01

    We report on the implementation of a multiplexer that uses superconducting quantum interference devices (SQUIDs) to read out low-impedance cryogenic detectors. Using prototype chips, a circuit was built which interfaces eight input SQUID channels with a close-packed array of eight transition-edge sensor (TES) infrared bolometers. Circuit elements were measured and crosstalk specifications are reported. Digital feedback is employed to flux-lock a single element in the array of SQUIDs.

  11. Neon color spreading in dynamic displays: temporal factors.

    PubMed

    Cicchini, Marco; Spillmann, Lothar

    2013-01-01

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

  12. Ceramic HTSC SQUID-based galvanometer

    SciTech Connect

    Uchaikin, S.V.; Hiep, L.H. )

    1992-06-01

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

  13. 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.

  14. Transparency and Coherence in rf SQUID Metamaterials

    NASA Astrophysics Data System (ADS)

    Anlage, Steven; Trepanier, Melissa; Zhang, Daimeng

    We have developed active metamaterials capable of quickly tuning their electrical and magnetic responses over a wide frequency range. These metamaterials are based on superconducting elements to form low loss, physically and electrically small, highly tunable structures for fundamental studies of extraordinarily nonlinear media. The meta-atoms are rf superconducting quantum interference devices (SQUIDs) that incorporate the Josephson effect. RF SQUIDs have an inductance which is strongly tunable with dc and rf magnetic fields and currents. The rf SQUID metamaterial is a richly nonlinear effective medium introducing qualitatively new macroscopic quantum phenomena into the metamaterials community, namely magnetic flux quantization and the Josephson effect. The coherent oscillation of the meta-atoms is strongly sensitive to the environment and measurement conditions, and we have developed several strategies to improve the coherence experimentally by exploiting ideas from nonlinear dynamics. The metamaterials also display a unique form of transparency whose development can be manipulated through multiple parametric dependences. We discuss these qualitatively new metamaterial phenomena. This work is supported by the NSF-GOALI and OISE Programs through Grant No. ECCS-1158644 and the Center for Nanophysics and Advanced Materials (CNAM).

  15. Compartment-Specific Phosphorylation of Squid Neurofilaments.

    PubMed

    Grant, Philip; Pant, Harish C

    2016-01-01

    Studies of the giant axon and synapse of third-order neurons in the squid stellate ganglion have provided a vast literature on neuronal physiology and axon transport. Large neuronal size also lends itself to comparative biochemical studies of cell body versus axon. These have focused on the regulation of synthesis, assembly, posttranslational modification and function of neuronal cytoskeletal proteins (microtubules (MTs) and neurofilaments (NFs)), the predominant proteins in axoplasm. These contribute to axonal organization, stability, transport, and impulse transmission responsible for rapid contractions of mantle muscles underlying jet propulsion. Studies of vertebrate NFs have established an extensive literature on NF structure, organization, and function; studies of squid NFs, however, have made it possible to compare compartment-specific regulation of NF synthesis, assembly, and function in soma versus axoplasm. Since NFs contain over 100 eligible sites for phosphorylation by protein kinases, the compartment-specific patterns of phosphorylation have been a primary focus of biochemical studies. We have learned that NF phosphorylation is tightly compartmentalized; extensive phosphorylation occurs only in the axonal compartment in squid and in vertebrate neurons. This extensive phosphorylation plays a key role in organizing NFs, in association with microtubules (MTs), into a stable, dynamic functional lattice that supports axon growth, diameter, impulse transmission, and synaptic activity. To understand how cytoskeletal phosphorylation is topographically regulated, the kinases and phosphatases, bound to NFs isolated from cell bodies and axoplasm, have also been studied. PMID:26795486

  16. Single SQUID frequency-domain multiplexer for large bolometer arrays

    SciTech Connect

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

    2001-08-20

    We describe the development of a frequency-domain superconducting quantum interference device (SQUID) multiplexer which monitors a row of low-temperature sensors simultaneously with a single SQUID. Each sensor is ac biased with a unique frequency and all the sensor currents are added in a superconducting summing loop. A single SQUID measures the current in the summing loop, and the individual signals are lock-in detected after the room temperature SQUID electronics. The current in the summing loop is nulled by feedback to eliminate direct crosstalk. We have built an eight-channel prototype and demonstrated channel separation and signal recovery.

  17. A nanoscale SQUID operating at high magnetic fields

    SciTech Connect

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

    2011-10-13

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

  18. A nanoscale SQUID operating at high magnetic fields

    SciTech Connect

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

    2011-10-13

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

  19. Allometry indicates giant eyes of giant squid are not exceptional

    PubMed Central

    2013-01-01

    Background The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. Results We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. Conclusions The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone. PMID:23418818

  20. Low Field Squid MRI Devices, Components and Methods

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  1. Low field SQUID MRI devices, components and methods

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  2. Low Field Squid MRI Devices, Components and Methods

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  3. Low field SQUID MRI devices, components and methods

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

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

    SciTech Connect

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

    1987-01-01

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

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

    SciTech Connect

    Drake, Jeremy J.

    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.

  6. Helium and neon isotopes in deep Pacific Ocean sediments

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  7. Experimental study on neon refrigeration system using commercial helium compressor

    NASA Astrophysics Data System (ADS)

    Ko, Junseok; Kim, Hyobong; Hong, Yong-Ju; Yeom, Hankil; Koh, Deuk-Yong; Park, Seong-Je

    2012-06-01

    In this study, we developed neon refrigeration system using commercial helium compressor which was originally designed for GM cryocooler. We performed this research as precedent study before developing neon refrigeration system for small-scale hydrogen liquefaction system. The developed system is based on precooled Linde-Hampson system with liquid nitrogen as precoolant. Design parameters of heat exchangers are determined from thermodynamic cycle analysis with operating pressure of 2 MPa and 0.4 MPa. Heat exchangers have concentric-tube heat exchanger configuration and orifice is used as Joule- Thomson expansion device. In experiments, pressure, temperature, mass flow rate and compressor input power are measured as charging pressure. With experimental results, the characteristics of heat exchanger, Joule-Thomson expansion and refrigeration effect are discussed. The developed neon refrigeration system shows the lowest temperature of 43.9 K.

  8. 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.

  9. Monte Carlo simulations of nanoscale focused neon ion beam sputtering.

    PubMed

    Timilsina, Rajendra; Rack, Philip D

    2013-12-13

    A Monte Carlo simulation is developed to model the physical sputtering of aluminum and tungsten emulating nanoscale focused helium and neon ion beam etching from the gas field ion microscope. Neon beams with different beam energies (0.5-30 keV) and a constant beam diameter (Gaussian with full-width-at-half-maximum of 1 nm) were simulated to elucidate the nanostructure evolution during the physical sputtering of nanoscale high aspect ratio features. The aspect ratio and sputter yield vary with the ion species and beam energy for a constant beam diameter and are related to the distribution of the nuclear energy loss. Neon ions have a larger sputter yield than the helium ions due to their larger mass and consequently larger nuclear energy loss relative to helium. Quantitative information such as the sputtering yields, the energy-dependent aspect ratios and resolution-limiting effects are discussed. PMID:24231648

  10. Fast imaging of intact and shattered cryogenic neon pellets.

    PubMed

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

    2014-11-01

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

  11. Comparison of the incremental and hierarchical methods for crystalline neon.

    PubMed

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

    2010-02-24

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

  12. Fast Imaging of Intact and Shattered Cryogenic Neon Pellets

    SciTech Connect

    Wang, Zhehui; Combs, Stephen Kirk; Baylor, Larry R; Foust, Charles R; Lyttle, Mark S; Meitner, Steven J; Rasmussen, David A

    2014-01-01

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

  13. Fast imaging of intact and shattered cryogenic neon pellets

    SciTech Connect

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

    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.

  14. 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.

  15. The isotopic composition of solar flare accelerated neon

    NASA Technical Reports Server (NTRS)

    Mewaldt, R. A.; Spalding, J. D.; Stone, E. C.; Vogt, R. E.

    1979-01-01

    The individual isotopes of neon in energetic solar-flare particles have been clearly resolved with a rms mass resolution of 0.20 amu. The ratios found are Ne-20/Ne-22 = 7.6 (+2.0, -1.8) and Ne-21/Ne-22 of no more than about 0.11 in the 11-26 MeV per nucleon interval. This isotopic composition is essentially the same as that of meteoritic planetary neon-A and is significantly different from that of the solar wind.

  16. Stark Widths of Spectral Lines of Neutral Neon

    NASA Astrophysics Data System (ADS)

    Dimitrijević, Milan S.; Simić, Zoran; Kovačević, Andjelka; Valjarević, Aleksandar; Sahal-Bréchot, Sylvie

    2015-12-01

    In order to complete Stark broadening data for Ne I spectral lines which are needed for analysis of stellar atmospheres, collisional widths and shifts (the so-called Stark broadening parameters) of 29 isolated spectral lines of neutral neon have been determined within the impact semiclassical perturbation method. Calculations have been performed for the broadening by collisions with electrons, protons and ionized helium for astrophysical applications, and for collisions with ionized neon and argon for laboratory plasma diagnostics. The shifts have been compared with existing experimental values. The obtained data will be included in the STARK-B database, which is a part of the Virtual Atomic and Molecular Data Center - VAMDC.

  17. SQUID magnetometry from nanometer to centimeter length scales

    SciTech Connect

    Hatridge, Michael J.

    2010-06-01

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

  18. Peripheral injury alters schooling behavior in squid, Doryteuthis pealeii.

    PubMed

    Oshima, Megumi; di Pauli von Treuheim, Theodor; Carroll, Julia; Hanlon, Roger T; Walters, Edgar T; Crook, Robyn J

    2016-07-01

    Animals with detectable injuries are at escalated threat of predation. The anti-predation tactic of schooling reduces individual predation risk overall, but it is not known how schooling behavior affects injured animals, or whether risks are reduced equally for injured animals versus other school members. In this laboratory study we examined the effects of minor fin injury on schooling decisions made by squid. Schooling behavior of groups of squid, in which one member was injured, was monitored over 24h. Injured squid were more likely to be members of a school shortly after injury (0.5-2h), but there were no differences compared with sham-injured squid at longer time points (6-24h). Overall, the presence of an injured conspecific increased the probability that a school would form, irrespective of whether the injured squid was a member of the school. When groups containing one injured squid were exposed to a predator cue, injured squid were more likely to join the school, but their position depended on whether the threat was a proximate visual cue or olfactory cue. We found no evidence that injured squid oriented themselves to conceal their injury from salient threats. Overall we conclude that nociceptive sensitization after injury changes grouping behaviors in ways that are likely to be adaptive. PMID:27108689

  19. Read-out electronics for DC squid magnetic measurements

    DOEpatents

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

    2002-01-01

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

  20. A Wsbnd Ne interatomic potential for simulation of neon implantation in tungsten

    NASA Astrophysics Data System (ADS)

    Backman, Marie; Juslin, Niklas; Huang, Guiyang; Wirth, Brian D.

    2016-08-01

    An interatomic pair potential for Wsbnd Ne is developed for atomistic molecular dynamics simulations of neon implantation in tungsten. The new potential predicts point defect energies and binding energies of small clusters that are in good agreement with electronic structure calculations. Molecular dynamics simulations of small neon clusters in tungsten show that trap mutation, in which an interstitial neon cluster displaces a tungsten atom from its lattice site, occurs for clusters of three or more neon atoms. However, near a free surface, trap mutation can occur at smaller sizes, including even a single neon interstitial in close proximity to a (100) or (110) surface.

  1. Planar thin film SQUID with integral flux concentrator

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  2. A SQUID gradiometer module with large junction shunt resistors

    NASA Astrophysics Data System (ADS)

    Qiu, Yang; Liu, Chao; Zhang, Shu-Lin; Zhang, Guo-Feng; Wang, Yong-Liang; Li, Hua; Zeng, Jia; Kong, Xiang-Yan; Xie, Xiao-Ming

    2014-08-01

    A dual-washer superconducting quantum interference device (SQUID) with a loop inductance of 350 pH and two on-washer integrated input coils is designed according to conventional niobium technology. In order to obtain a large SQUID flux-to-voltage transfer coefficient, the junction shunt resistance is selected to be 33 Ω. A vertical SQUID gradiometer module with a baseline of 100 mm is constructed by utilizing such a SQUID and a first-order niobium wire-wound antenna. The sensitivity of this module reaches about 0.2 fT/(cm·Hz1/2) in the white noise range using a direct readout scheme, i.e., the SQUID is directly connected to an operational amplifier, in a magnetically shielded room. Some magnetocardiography (MCG) measurements with a sufficiently high signal-to-noise ratio (SNR) are demonstrated.

  3. A Closed Neon Liquefier System for Testing Superconducting Devices

    NASA Astrophysics Data System (ADS)

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

    2006-04-01

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

  4. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    NASA Technical Reports Server (NTRS)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  5. Neon and CO2 adsorption on open carbon nanohorns.

    PubMed

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

    2013-07-30

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

  6. Infrared absorption spectra of methylidene radicals in solid neon.

    PubMed

    Lu, Hsiao-Chi; Lo, Jen-Iu; Lin, Meng-Yeh; Peng, Yu-Chain; Chou, Sheng-Lung; Cheng, Bing-Ming; Ogilvie, J F

    2014-07-28

    Infrared absorption lines of methylidene--(12)C(1)H, (13)C(1)H, and (12)C(2)H--dispersed in solid neon at 3 K, recorded after photolysis of methane precursors with vacuum-ultraviolet light at 121.6 nm, serve as signatures of these trapped radicals. PMID:24912563

  7. Capture of neon atoms by sup 4 He clusters

    SciTech Connect

    Scheidemann, A.; Toennies, J.P. ); Northby, J.A. )

    1990-04-16

    Neon atoms are captured by helium clusters in a crossed-beam experiment. The capture process depends strongly on the cluster beam source conditions. We identify a sharply defined region corresponding to expansions passing near the critical point for which the capture probability is anomalously large.

  8. Cosmogenic neon from precompaction irradiation of Kapoeta and Murchison

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  9. 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…

  10. Presynaptic calcium currents in squid giant synapse.

    PubMed Central

    Llinás, R; Steinberg, I Z; Walton, K

    1981-01-01

    A voltage clamp study has been performed in the presynaptic terminal of the squid stellate ganglion. After blockage of the voltage-dependent sodium and potassium conductances, an inward calcium current is demonstrated. Given a step-depolarization pulse, this voltage- and time-dependent conductance has an S-shaped onset. At the "break" of the voltage step, a rapid tail current is observed. From these results a kinetic model is generated which accounts for the experimental results and predicts for the time course and amplitude a possible calcium entry during presynaptic action potentials. Images FIGURE 1 PMID:7225510

  11. 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.

  12. 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

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2004-10-01

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

  15. A simple three-channel dc SQUID system using time domain multiplexing

    NASA Astrophysics Data System (ADS)

    Mück, M.; Korn, M.; Mugford, C. G. A.; Kycia, J. B.

    2004-08-01

    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 to the room temperature electronics. We present a simple time domain multiplexed read-out scheme which requires only a single SQUID read-out circuit that is successively switched between all the SQUIDs. By connecting all the SQUIDs and all the feedback coils in series, this time domain multiplexed system requires many fewer wires between the SQUIDs and the room temperature read-out circuit than other multichannel systems.

  16. Cross-linking Chemistry of Squid Beak*

    PubMed Central

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

    2010-01-01

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

  17. Cross-linking chemistry of squid beak.

    PubMed

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

    2010-12-01

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

  18. The curvy photonics of squid camouflage

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  19. Crystallization and crystal properties of squid rhodopsin

    SciTech Connect

    Murakami, Midori; Kitahara, Rei; Gotoh, Toshiaki; Kouyama, Tsutomu

    2007-06-01

    Truncated rhodopsin from the retina of the squid Todarodes pacificus was extracted and crystallized by the sitting-drop vapour-diffusion method. Hexagonal crystals grown in the presence of octylglucoside and ammonium sulfate diffracted to 2.8 Å resolution. Rhodopsin, a photoreceptor membrane protein in the retina, is a prototypical member of the G-protein-coupled receptor family. In this study, rhodopsin from the retina of the squid Todarodes pacificus was treated with V8 protease to remove the C-terminal extension. Truncated rhodopsin was selectively extracted from the microvillar membranes using alkyl glucoside in the presence of zinc ions and was then crystallized by the sitting-drop vapour-diffusion method. Of the various crystals obtained, hexagonal crystals grown in the presence of octylglucoside and ammonium sulfate diffracted to 2.8 Å resolution. The diffraction data suggested that the crystal belongs to space group P6{sub 2}, with unit-cell parameters a = b = 122.1, c = 158.6 Å. Preliminary crystallographic analysis, together with linear dichroism results, suggested that the rhodopsin dimers are packed in such a manner that their transmembrane helices are aligned nearly parallel to the c axis.

  20. Base distance optimization for SQUID gradiometers

    SciTech Connect

    Garachtchenko, A.; Matlashov, A.; Kraus, R.

    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.

  1. 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.

  2. Recent Results of a New Microwave SQUID Multiplexer

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  3. Whole-head SQUID system in a superconducting magnetic shield.

    PubMed

    Ohta, H; Matsui, T; Uchikawa, Y

    2004-01-01

    We have constructed a mobile whole-head SQUID system in a superconducting magnetic shield - a cylinder of high Tc superconductor BSCCO of 65 cm in diameter and 160 cm in length. We compared the noise spectra of several SQUID sensors of SNS Josephson junctions in the superconducting magnetic shield with those of the same SQUID sensors in a magnetically shielded room of Permalloy. The SQUID sensors in the superconducting magnetic shield are more than 100 times more sensitive than those in a magnetically shielded room of Permalloy below 1 Hz. We tested the whole-head SQUID system in the superconducting magnetic shield observing somatosensory signals evoked by stimulating the median nerve in the right wrist of patients by current pulses. We present data of 64 and 128 traces versus the common time axis for comparison. Most sensory responses of human brains phase out near 250 ms. However monotonic rhythms still remain even at longer latencies than 250 ms. The nodes of these rhythm are very narrow even at these longer latencies just indicating low noise characteristics of the SQUID system at low-frequencies. The current dipoles at the secondary somatosensory area SII are evoked at longer latencies than 250 ms contributing to a higher-level brain function. The SQUID system in a superconducting magnetic shield will also have advantages when it is used as a DC MEG to study very slow activities and function of the brain. PMID:16012595

  4. High speed non-latching SQUID binary ripple counter

    NASA Astrophysics Data System (ADS)

    Silver, A. H.; Phillips, R. R.; Sandell, R. D.

    1985-03-01

    High speed, single flux quantum (SFQ) binary scalers are important components in superconducting analog-to-digital converters (ADC). This paper reviews the concept for a SQUID ADC and the design of an SFQ binary ripple counter, and reports the simulation of key components, and fabrication and performance of non-latching SQUID scalers and SFQ binary ripple counters. The SQUIDs were fabricated with Nb/Nb2O5/PbIn junctions and interconnected by monolithic superconducting transmission lines and isolation resistors. Each SQUID functioned as a bistable flip-flop with the input connected to the center of the device and the output across one junction. All junctions were critically damped to optimize the pulse response. Operation was verified by observing the dc I-V curves of successive SQUIDs driven by a cw pulse train generated on the same chip. Each SQUID exhibited constant-voltage current steps at 1/2 the voltage of the preceding device as expected from the Josephson voltage-to-frequency relation. Steps were observed only for the same voltage polarity of successive devices and for proper phase bias of the SQUID. Binary frequency division was recorded up to 40GHz for devices designed to operate to 28GHz.

  5. High speed non-latching squid binary ripple counter

    SciTech Connect

    Silver, A.H.; Phillips, R.R.; Sandell, R.D.

    1985-03-01

    High speed, single flux quantum (SFQ) binary scalers are important components in superconducting analog-to-digital converters (ADC). This paper reviews the concept for a SQUID ADC and the design of an SFQ binary ripple counter, and reports the simulation of key components, and fabrication and performance of non-latching SQUID scalers and SFQ binary ripple counters. The SQUIDs were fabricated with Nb/Nb/sub 2/O/sub 5//PbIn junctions and interconnected by monolithic superconducting transmission lines and isolation resistors. Each SQUID functioned as a bistable flip-flop with the input connected to the center of the device and the output across one junction. All junctions were critically damped to optimize the pulse response. Operation was verified by observing the dc I-V curves of successive SQUIDs driven by a cw pulse train generated on the same chip. Each SQUID exhibited constant-voltage current steps at 1/2 the voltage of the preceding device as expected from the Josephson voltage-to-frequency relation. Steps were observed only for the same voltage polarity of successive devices and for proper phase bias of the SQUID. Binary frequency division was recorded up to 40GHz for devices designed to operate to 28GHz.

  6. Ginzburg-Landau modeling of Nano-SQUIDs

    NASA Astrophysics Data System (ADS)

    Kirtley, John; Hazra, Dibyendu; Hasselbach, Klaus; Buisson, Olivier

    2014-03-01

    NanoSQUIDs are micron-sized Superconducting Quantum Interference Devices with narrow (50 nm) sized constrictions as weak links. They are used for, e.g., studying switching dynamics in magnetic nanoparticles and high spatial resolution magnetic microscopy. When the constriction dimensions become comparable to or larger than the superconducting coherence length, the current-phase relations become non-sinusoidal, reducing the flux modulation depth and increasing the thermally activated flux noise. We have numerically solved the Ginzburg-Landau (GL) equations for the nanoSQUID geometry to obtain current-phase relations, the dependence of critical current on magnetic flux, and the thermally activated escape rates. We predict NanoSQUIDs with short coherence lengths to have critical current distribution widths, and therefore flux noises, proportional to T1/2, as opposed to tunnel junction SQUIDs, which are proportional to T2/3. Our GL simulations predict that the ultimate noise performance of Al nanoSQUIDs, with their longer coherence lengths, should be better than Nb nanoSQUIDs, with suspended bridge Al/Nb nanoSQUIDs intermediate between the two.

  7. The energy dependence of the neon-22 excess in the cosmic radiation

    NASA Technical Reports Server (NTRS)

    Herrstroem, N. Y.; Lund, N.

    1985-01-01

    It has been recognized now for some time that the heavy neon isotope, neon-22, is overabundant by a factor of 3 to 4 with respect to neon-22 in the cosmic ray source compared to the ratio of these isotopes in the Solar System. In view of the otherwise remarkable similarity of the chemical composition of the cosmic ray source and the composition of the Solar Energetic Particles, the anomaly regarding the neon isotopes is so much more striking. The observed excess of neon-22 is too large to be explained as a result of the chemical evolution of the Galaxy since the formation of the Solar System. Further information on the origin of the neon-22 excess may come from a comparison of the energy spectra of the two neon isotopes. If the cosmic radiation in the solar neighborhood is a mixture of material from several sources, one of which has an excess of neon-22, then the source energy spectra of neon-20 and neon-22 may differ significantly.

  8. 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.

  9. Dynamics of a SQUID with topologically nontrivial barriers

    NASA Astrophysics Data System (ADS)

    Rahmonov, I. R.; Shukrinov, Yu. M.; Dawood, R.

    2016-03-01

    The phase dynamics of a SQUID consisting of Josephson junctions with topologically nontrivial barriers has been studied. Its comparative analysis with the dynamics of a conventional SQUID has been performed. The current-voltage characteristics have been calculated. The dependence of the return current on the magnetic field has been found. It has been shown that the branch of the current-voltage characteristic corresponding to the resonance frequency in the case of the SQUID with nontrivial barriers is displaced by √ 2 over voltage. This effect can be used for the detection of Majorana fermions.

  10. Resonance detection of dark matter axions using a DC SQUID

    NASA Astrophysics Data System (ADS)

    Popov, V. A.

    2016-02-01

    A method for detecting dark matter axions in which a dc SQUID serves as a detector is proposed. The SQUID is shown to be able to detect the magnetic field perturbations induced by its interaction with axions. The resonance signal appears as a current step in the SQUID current-voltage characteristic. The voltage of the step corresponds to the axion mass, while its height depends on the axion energy density in near-Earth space. The proposed method is aimed at detecting axions with masses m a ≲ 10-4 eV, which are of interest for both cosmology and particle physics.

  11. Two-stage series array SQUID amplifier for space applications

    NASA Astrophysics Data System (ADS)

    Tuttle, J. G.; DiPirro, M. J.; Shirron, P. J.; Welty, R. P.; Radparvar, M.

    We present test results for a two-stage integrated SQUID amplifier which uses a series array of d.c. SQUIDS to amplify the signal from a single input SQUID. The device was developed by Welty and Martinis at NIST and recent versions have been manufactured by HYPRES, Inc. Shielding and filtering techniques were employed during the testing to minimize the external noise. Energy resolution of 300 h was demonstrated using a d.c. excitation at frequencies above 1 kHz, and better than 500 h resolution was typical down to 300 Hz.

  12. Martian paleomagnetism with the SQUID microscope

    NASA Astrophysics Data System (ADS)

    Weiss, Benjamin Paul

    Rocks should preserve natural remanent magnetizations with stable directional and intensity information at levels ˜1000 times below that of the noise level on today's best moment magnetometers. The superconducting quantum interference device (SQUID) Microscope is a new, high-resolution magnetometer that can now detect such weak signals. It maps the magnetic fields above samples with a spatial resolution of <100 mum and a moment sensitivity of <10 -15 Am2. It therefore provides data with a resolution directly comparable with that of other common petrographic techniques. This thesis describes applications of SQUID microscopy to a variety of problems in the planetary sciences. A SQUID microscope paleomagnetic conglomerate test demonstrates that ALH84001 has been cooler than ˜40°C since before its ejection from the surface of Mars at 15 Ma. Because this temperature cannot sterilize most bacteria or eukarya, these data support the hypothesis that meteorites could transfer life between planets in the solar system. These and other data on panspermia demand a re-evaluation of the long-held assumption that terrestrial life evolved in isolation on Earth. Subsequent magnetic and textural studies of the meteorite show that 4 Ga ALH84001 carbonates containing magnetite and pyrrhotite carry a stable natural remanent magnetization. 40Ar/39Ar thermochronology demonstrates that this magnetization originated at 3.9--4.1 Ga on Mars. This magnetization is the oldest known for a planetary rock, and its strong intensity suggests that Mars had generated a geodynamo at or before 4 Ga. The intensity of the field that magnetized ALH84001 was roughly within an order of magnitude of that at the surface of the present-day Earth, sufficient for magnetotaxis by the bacteria whose magnetofossils have been reported in ALH84001 and possibly for the production of the strong crustal anomalies. 40Ar/39Ar thermochronology calculations also provide an explanation for why ALH84001 contains a sample of

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

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

  14. A dielectric barrier discharge in neon at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Ran, Junxia; Luo, Haiyun; Wang, Xinxin

    2011-08-01

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

  15. Muon transfer from hydrogen and deuterium atoms to neon

    SciTech Connect

    Jacot-Guillarmod, R. )

    1995-03-01

    The muon exchange reactions from the ground state of muonic protium and deuterium atoms to neon are studied. Measurements have been performed in binary gas mixtures at room temperature. The transfer rate from thermalized muonic deuterium is found to exceed by about an order of magnitude the one from muonic protium. On the other hand, an energy dependence of the rate from [mu][ital d] is revealed, while none is observed from [mu][ital p]. The intensity patterns of the muonic Lyman series of neon resulting from the muon exchange differ from one hydrogen isotope to the other, the most obvious discrepancy being the presence of the muonic Ne(7-1) line after transfer from [mu][ital d], whereas this line is absent by transfer from [mu][ital p]. This indicates that the muon is transferred to the level [ital n][sub [ital p

  16. 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.

  17. 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.

  18. 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. This design precludes nucleate boiling in the flow channels as they are too small to handle vapor flow. Consequently, it was necessary to determine boiling incipience under the operating conditions of the magnet system. 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 plus or minus 15 percent

  19. Realizing and optimizing an atomtronic SQUID

    NASA Astrophysics Data System (ADS)

    Mathey, Amy C.; Mathey, L.

    2016-05-01

    We demonstrate how a toroidal Bose–Einstein condensate with a movable barrier can be used to realize an atomtronic SQUID. The magnitude of the barrier height, which creates the analogue of an SNS junction, is of crucial importance, as well as its ramp-up and -down protocol. For too low of a barrier, the relaxation of the system is dynamically suppressed, due to the small rate of phase slips at the barrier. For a higher barrier, the phase coherence across the barrier is suppressed due to thermal fluctuations, which are included in our Truncated Wigner approach. Furthermore, we show that the ramp-up protocol of the barrier can be improved by ramping up its height first, and its velocity after that. This protocol can be further improved by optimizing the ramp-up and ramp-down time scales, which is of direct practical relevance for on-going experimental realizations.

  20. Charge radii of neon isotopes across the sd neutron shell

    SciTech Connect

    Marinova, K.; Geithner, W.; Kappertz, S.; Kloos, S.; Kotrotsios, G.; Neugart, R.; Wilbert, S.; Kowalska, M.; Keim, M.; Blaum, K.; Lievens, P.; Simon, H.

    2011-09-15

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

  1. Magnetic Field Sampling using a Pulsed Hysteretic SQUID

    NASA Astrophysics Data System (ADS)

    Kwon, S. P.; Vlahacos, C. P.; Berkley, A. J.; Gubrud, M. A.; Wellstood, F. C.; Cawthorne, A.

    2004-03-01

    Weak magnetic field detection using a non-hysteretic DC SQUID with Flux-Locked-Loop electronics is typically limited to 1MHz bandwidth or less. However, there is demand for larger bandwidth magnetic field detection for use in the semiconductor industry. We have studied the possibility of using a 4.2K hysteretic trilayer Nb DC SQUID, fabricated by Hypres Inc., with pulsed bias current to increase the bandwidth by an order of magnitude or more. The technique is based on the fast switching of a hysteretic SQUID from the superconducting state to the normal conducting state. By observing the switching of the SQUID, the applied magnetic field at the time of a pulse can be followed. Experimental results show that the technique can be used to follow magnetic fields of up to 60MHz with 5ns pulses. With shorter pulses and better electronics, the technique could further increase the bandwidth by another order of magnitude.

  2. Development of a colorimetric sensor array for squid spoilage assessment.

    PubMed

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

    2015-05-15

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

  3. Squid as nutrient vectors linking Southwest Atlantic marine ecosystems

    NASA Astrophysics Data System (ADS)

    Arkhipkin, Alexander I.

    2013-10-01

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

  4. Integrated SQUID sensors for low cross-talk multichannel systems

    NASA Astrophysics Data System (ADS)

    Granata, C.; Vettoliere, A.; Luiso, M.; Russo, M.

    2006-06-01

    We present a fully integrated dc-SQUID magnetometer based on niobium technology including a new feedback coil design. In respect to a standard SQUID design, such a feedback-coil design was optimized in order to reduce the mutual inductance with the neighbours and to increase the coupling with the pick-up coil of the SQUID itself. In such a way, it is possible to reduce cross-talks due to both feedback coil and wires. Experimental results about the characterization of the device and the crosstalk measurements are reported. The measurements have been performed in liquid helium using a low noise readout electronics specifically designed for large multichannel SQUID based instrumentations. The experimental data have shown a substantial reduction of cross-talk between neighbouring sensors.

  5. Perception of neon color spreading in 3-6-month-old infants.

    PubMed

    Yang, Jiale; Kanazawa, So; Yamaguchi, Masami K

    2009-12-01

    Although lots of studies about neon color spreading have been reported, few of these studies have focused on the perceptual development of it in human infants. Therefore, this study explores the perceptual development of neon color spreading in infants. In experiment 1, we examined 3-6-month-olds' perception of neon color spreading in static conditions. In experiment 2, we examined 3-6-month-olds' perception of neon color spreading in moving conditions. Our results suggest that while only 5-6-month-old infants show a preference for neon color spreading in the static condition, 3-4-month-old infants also prefer neon color spreading if motion information is available. PMID:19836080

  6. Nova LMC 1990 no. 1: The first extragalactic neon nova

    NASA Technical Reports Server (NTRS)

    Sonneborn, George; Shore, Steven N.; Starrfield, Sumner G.

    1990-01-01

    International Ultraviolet Explorer (IUE) observations of nova LMC (Large Magellanic Cloud) 1990 No. 1, the first neon (or ONeMg) nova observed outside the Galaxy are presented. The observations were obtained from 17 Jan. to Mar. 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 3-4 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 5 delta 1240 and C 4 delta 1550 lines. The maximum ejection velocity was approximately 8000 km/s, based on the blue absorption edge of the C 4 P-Cygni profile. Early in the outburst of Nova LMC 1990 No. 1 the UV luminosity alone was approximately 3 times 10 to the 38th power erg/sec, implying that the bolometric luminosity was well in excess of the Eddington luminosity for a one solar mass object.

  7. Helium-neon laser improves skin repair in rabbits.

    PubMed

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

    2012-12-01

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

  8. SQUID magnetometry applied as non-invasive electroanalytic chemical technique

    SciTech Connect

    Jette, B.D.; MacVicar, M.L.A. )

    1991-03-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  10. ELECTROPHORETIC AND IMMUNOLOGICAL STUDIES OF SQUID AXOPLASM PROTEINS.

    PubMed

    HUNEEUS-COX, F

    1964-03-01

    By disc electrophoresis of the axoplasm of Dosidicus gigas, 14 protein bands have been resolved. Anti-bodies to the intra-axonal proteins and to squid blood proteins were produced in rabbits. By Ouchterlony's technique, six antigenic components can be demonstrated in axoplasm; the combined use of disc electrophoresis and immune diflusion in agar resolves seven antigenic components in axoplasm; none of these components is detectable in squid blood. PMID:14107426

  11. High transition-temperature SQUID magnetometers and practical applications

    SciTech Connect

    Dantsker, E

    1997-05-01

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

  12. A scanning SQUID microscope with 200 MHz bandwidth

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    We developed a scanning DC SQUID microscope with novel readout electronics capable of wideband sensing of RF magnetic fields from 50 to 200 MHz and simultaneously providing closed-loop response at kHz frequencies. To overcome the 20 MHz bandwidth limitation of traditional closed-loop SQUIDs, a flux-modulated closed-loop simultaneously locks the SQUID quasi-static flux and flux-biases the SQUID for amplification of the RF flux up to Φ0/4 in amplitude. Demodulating the SQUID voltage with a double lock-in technique yields a signal representative of both the amplitude and phase of the RF flux. This provides 80 dB of a linear dynamic range with a flux noise density of 4 μΦ0 Hz-1/2 at 200 MHz for a Y Ba2Cu3O7 bi-crystal SQUID at 77 K. We describe the electronics’ performance and present images for RF magnetic field of the travelling wave in a coplanar waveguide, the standing wave in an open-circuited microstrip, and a surface mounted device antenna.

  13. High-performance DC SQUID read-out electronics

    NASA Astrophysics Data System (ADS)

    Drung, Dietmar

    2002-03-01

    The dynamic behavior of superconducting quantum interference devices (SQUIDs) operated in a flux-locked loop (FLL) is discussed using a simple mathematical description. It is shown that the slew rate of any FLL is limited by the linear flux range of the SQUID Φlin and the effective loop delay td to approximately Φ˙f, max=Φ lin/(4t d) if a one-pole integrator is used. This allows one to estimate the dynamic limits of both analog SQUIDs with flux modulation or direct read-out and digital SQUIDs with on-chip read-out. In addition to theoretical limits, practically achievable performance is presented using our latest direct-coupled FLL electronics as an example of state-of-the-art SQUID read-out. This electronics is designed for both low-critical temperature (low- Tc) and high- Tc SQUIDs. It combines low noise with high bandwidth and slew rate. All functions are computer controlled using a LabVIEW ® program. An automatic bias voltage tuning circuit increases the system stability in case of large cryogenic temperature fluctuations. Furthermore, an ultra-low-noise current source is integrated into the FLL board which can be used to supply a coil system compensating the Earth's magnetic field of about 60 μT while producing only 17 fT/ Hz extra noise at 1 kHz and 41 fT/ Hz at 1 Hz, respectively.

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

    PubMed

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

    2000-12-01

    A study for the characterization of frozen giant squid mantle (meat) protein stored at -25 degrees C for 8 month was started. In the present research, the following functional properties were investigate: emulsifying, water holding and gel forming capacities. Optimal conditions for the separation and differentiation of miofibrillar and sarcoplasmatic proteins were also studied. It was found that the unfrozen giant squid mantle meat es capable of emulifying 2.817,4 g of oil/g of protein and holding capacity was 3.64 g of water/g of protein. Related to the gel forming capacity, it was not obtain, probably due to excessive storage of the meat. With regard to miofibrilar protein obtention of the squid mantle meat, it was found that two low ionic strength washings (I = 0.05), the sarcoplasmic proteins were practically eliminated from the protein matrix. The differentiation of miofibrilar and sarcoplasmatic proteins was obtained by PAGE-SDS of the squid mantle meat extracted at two different ionic strength (I = 0.05 and I = 0.5). This work demonstrates that the giant squid mantle protein has a high emulsifying and water holding capacity, and it can be used, as a raw material, for the improvement of sausage products. About the gelling products, more studies will be necessary with fresh squid mantle meat to conclude about this functional property. PMID:11464670

  15. An investigation of pinch welds using HTS SQUIDs

    NASA Astrophysics Data System (ADS)

    Carr, Chris; Espy, Michelle A.; Urbaitis, Algis V.; Kraus, Robert H., Jr.

    2006-05-01

    To contain high-pressure gases inside a pressure vessel a seal is often made in a thin-walled tube, known as the stem tube, that connects the gas reservoir and the vessel. This seal can be achieved through the use of a resistance pinch weld that forms with only a limited amount of melting occurring. The lack of melting makes applying traditional post-weld nondestructive evaluation (NDE) techniques extremely difficult. The welds of interest here are made from 304L stainless steel (typically 3.8 mm diameter and 38 mm long) and have a non-uniform geometry that does not inherently lend itself to either eddy current or static field SQUID-based measurement techniques. We perform these NDE measurements with both the sample and the SQUID located inside local electromagnetic shielding. SQUID data are presented as individual time series traces for a set of welds that were fabricated using a broad range of fabrication parameters, and a comparison is made between the SQUID-based results and the known parameters. With the limited spatial resolution offered by our present SQUID system, it is not clear if weld quality can be evaluated from purely SQUID-based results.

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

    SciTech Connect

    Khasenov, M U

    2011-03-31

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

  17. Stable Fly Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult stable flies feed on the blood of humans, pets and livestock, inflicting painful bites. Stable flies need one and sometimes two bloodmeals each day to develop their eggs. Unlike mosquitoes where only the females bloodfeed, both male and female stable flies require blood to reproduce. Stable fl...

  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. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    SciTech Connect

    Heaney, M.B. . Dept. of Physics Lawrence Berkeley Lab., CA )

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al{sub 2}O{sub 3}/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 {times} 10{sup 17} in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO{sub 3} crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

  20. Processing of polarized light by squid photoreceptors.

    PubMed

    Saidel, W M; Lettvin, J Y; MacNichol, E F

    Behavioural tests have demonstrated that cephalopods can discriminate light polarized in different planes, and the receptors have been localized by electrophysiological studies of the eye. Discrimination of the plane of polarization is a consequence of both the structure of the microvilli in the outer segments of the photoreceptors and the orientation of the photosensitive chromophore on these membranes. However, between the depolarizing receptor response resulting from photoreception and the behaviour of the animal, nothing is known about neuronal processing of polarized light by cephalopods. Here we show that some squid photoreceptors discriminate the plane of polarization within the spike train, and that any particular plane is seen as a variable intensity. Given the well known orthogonal orientation of microvilli in outer segments of adjacent photoreceptors and the physiological preference for one of two mutually perpendicular planes of polarization by single photoreceptors, we conclude that cephalopod vision is based on two complementary views of the world, each determined by the transformation of polarization-sensitive receptors into complementary intensity scales. A visual system based on this transformation would lead to enhanced contrast underwater and visualization of object details obscured by confounding highlights. PMID:6877374

  1. 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 μT. 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 μT 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.

  2. The NEON Science Commissioning Plan: Strategies for Confirming System Operation

    NASA Astrophysics Data System (ADS)

    Wirth, G. D.; Thorpe, A.; Buur, H.

    2015-12-01

    A transformation is underway in the field of ecological monitoring as compelling science questions motivate us to build ever-larger networks aiming to acquire uniform datasets over wide geographical ranges and long timescales. The National Ecological Observatory Network (NEON), currently under construction across the U.S., represents the most ambitious such effort to characterize ecology at the continental scale. When completed in 2017, NEON will begin a 30-year program to monitor the state of North American ecosystems at scores of independent sites by employing a combination of terrestrial and aquatic sensors, organismal, biogeochemical, and hydrological sampling conducted by field staff, and airborne remote-sensing imaging and spectroscopy. Simply building and bringing such complex, long-term monitoring networks online is, however, insufficient to produce a useful result: the science team must also confirm that the system fulfills its essential mission to generate accurate and uniform data from all sites over time. This is the role of Science Commissioning, the process which completes the construction stage by confirming that the system operates as designed before entering full operations. Ideally, Science Commissioning involves simply testing the completed system against all applicable science requirements. In the real world of large, complex networks, planners of Science Commissioning must grapple with several key questions: How can we verify that the measurements from a given subsystem reflect "truth"? How can we ensure that similar subsystems at different sites return equivalent results? How can we confirm that data from the same site remain comparable over long periods of time? How can we conduct meaningful tests on a large system in a reasonable amount of time and effort? We describe the specific strategies NEON is developing to meet these challenges and the implications for other large ecological monitoring networks.

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  4. Periodic local-MP2 computational study of crystalline neon.

    PubMed

    Halo, Migen; Casassa, Silvia; Maschio, Lorenzo; Pisani, Cesare

    2009-01-21

    Face-centered-cubic crystalline Neon is taken as a test system to explore the influence of computational parameters on the quality of the MP2 solution provided by the Cryscor program using a local-correlation approach. The effect of the various approximations adopted is analyzed: basis set limitations, finite size of excitation domains, truncation of the tails of the local functions, approximate evaluation of two-electron integrals, estimate (by extrapolation) of long-range contributions are shown to play roles of different importance. The Ne2 dimer is used as an auxiliary test case in order to allow comparison with recent and accurate literature data. PMID:19283277

  5. Optimizing Sampling Efficiency for Biomass Estimation Across NEON Domains

    NASA Astrophysics Data System (ADS)

    Abercrombie, H. H.; Meier, C. L.; Spencer, J. J.

    2013-12-01

    Over the course of 30 years, the National Ecological Observatory Network (NEON) will measure plant biomass and productivity across the U.S. to enable an understanding of terrestrial carbon cycle responses to ecosystem change drivers. Over the next several years, prior to operational sampling at a site, NEON will complete construction and characterization phases during which a limited amount of sampling will be done at each site to inform sampling designs, and guide standardization of data collection across all sites. Sampling biomass in 60+ sites distributed among 20 different eco-climatic domains poses major logistical and budgetary challenges. Traditional biomass sampling methods such as clip harvesting and direct measurements of Leaf Area Index (LAI) involve collecting and processing plant samples, and are time and labor intensive. Possible alternatives include using indirect sampling methods for estimating LAI such as digital hemispherical photography (DHP) or using a LI-COR 2200 Plant Canopy Analyzer. These LAI estimations can then be used as a proxy for biomass. The biomass estimates calculated can then inform the clip harvest sampling design during NEON operations, optimizing both sample size and number so that standardized uncertainty limits can be achieved with a minimum amount of sampling effort. In 2011, LAI and clip harvest data were collected from co-located sampling points at the Central Plains Experimental Range located in northern Colorado, a short grass steppe ecosystem that is the NEON Domain 10 core site. LAI was measured with a LI-COR 2200 Plant Canopy Analyzer. The layout of the sampling design included four, 300 meter transects, with clip harvests plots spaced every 50m, and LAI sub-transects spaced every 10m. LAI was measured at four points along 6m sub-transects running perpendicular to the 300m transect. Clip harvest plots were co-located 4m from corresponding LAI transects, and had dimensions of 0.1m by 2m. We conducted regression analyses

  6. The abundances of neon, sulfur, and argon in planetary nebulae

    NASA Technical Reports Server (NTRS)

    Beck, S. C.; Lacy, J. H.; Townes, C. H.; Aller, L. H.; Geballe, T. R.; Baas, F.

    1981-01-01

    New infrared observations of Ne II, Ar III, and S IV are used in optical observations of other ionization states of the considered elements to evaluate the abundances of neon, argon, and sulfur in 18 planetary nebulae. Attention is also given to one or more of the infrared lines in 18 other nebulae. It is pointed out that S IV was detected in approximately 90% of the observed objects, while Ar III was found in about 80%, and Ne II in roughly one-third. It is noted that optical observations typically include only a limited region of the nebula, while the infrared measurements frequently involve integration over the entire nebular image.

  7. Noble gases in diamonds - Occurrences of solarlike helium and neon

    NASA Technical Reports Server (NTRS)

    Honda, M.; Reynolds, J. H.; Roedder, E.; Epstein, S.

    1987-01-01

    Seventeen diamond samples from diverse locations were analyzed for the contents of He, Ar, Kr, and Xe, and of their isotopes, using a Reynolds (1956) type glass mass spectrometer. The results disclosed a large spread in the He-3/He-4 ratios, ranging from values below atmospheric to close to the solar ratio. In particular, solarlike He-3/He-4 ratios were seen for an Australian colorless diamond composite and an Arkansas diamond, which also displayed solarlike neon isotopic ratios. Wide variation was also observed in the He-4/Ar-40 ratios, suggesting a complex history for the source regions and the diamond crystallization processes.

  8. Expected intensities of solar neon-like ions

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Kastner, S. O.

    1985-01-01

    A study of the expected intensities of the stronger solar neon-like ion emission lines, some not yet observed, is carried out to compare with the observational situation. The potential usefulness of the 2p5 3s(3P2) - 2p6 forbidden line as a density diagnostic is discussed, and new electric quadrupole lines in the soft X-ray range are noted. 'Observability diagrams' are presented as a convenient overview of the known and unobserved lines. The S VII resonance lines appear to have anomalous intensities.

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

    PubMed

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

    2007-01-12

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

  10. 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.

  11. Cryogenic Integrated Offset Compensation for Time Domain SQUID Multiplexing

    NASA Astrophysics Data System (ADS)

    Prêle, D.; Voisin, F.; Martino, J.; Bréelle, E.; Bordier, G.; Piat, M.

    2012-06-01

    Superconducting QUantum Interference Device (SQUID) multiplexing is a common technique in the use of large arrays of Transition Edge Sensors (TES). A Time Domain Multiplexer (TDM) combines input TES signals into one output signal using several SQUIDs. Different TES, SQUID and amplifier characteristics induce unavoidable different offsets on the multiplexed signal. Additionally, given the periodicity of the SQUID characteristic, the Flux Locked Loop (FLL) operating point is only defined modulo Φ 0. This can lead to a large output offset. In multiplexed mode, the difference between offsets associated with different pixels can induce a parasitic signal which is often larger than that of the TES. These offset signals drastically constrain the readout dynamic range and thus the maximum gain allowed. They also limit the signal-to-noise ratio, the FLL stability and the multiplexing frequency. Offsets in SQUID readout are discussed and offset compensation for TDM is presented. The dynamic calibration and compensation on a simplified 4:1 TDM are demonstrated in simulation. Dynamic offset compensation is being implemented on a cryogenic SiGe integrated circuit operated at 4 K for 128:1 TDM.

  12. Environmental effects on recreational squid jigging fishery catches

    NASA Astrophysics Data System (ADS)

    Cabanellas-Reboredo, Miguel; Alós, Josep; Palmer, Miquel; Morales-Nin, Beatriz

    2012-08-01

    Experimental fishing sessions simulating the operating procedures of the recreational fishery for the European squid that operates at inshore Palma Bay (Balearic Islands, Spain) were conducted to investigate the effects of environmental variables on squid catches. The catch per unit of effort (cpue) of recreational-like jigging sessions showed a seasonal pattern (higher cpue during colder months). Two alternative hypotheses can explain such a pattern. First, squid could migrate inshore during colder months to seek spatio-temporal windows within which the sea temperature maximize spawning success. Second, the timing of the seasonal reproductive peak and the growth rate of any given cohort would result in a higher percentage of squid whose body size is greater than the gear-specific vulnerability threshold during the colder months. The combination of environmental variables that maximized cpue was a low sea surface temperature, a low windspeed, low atmospheric pressure, and days close to the new moon. A specific period of the day, narrowly around sunset, favoured the catches. Within this narrow period, the sunlight is still sufficient to allow the recreational fishing lures to be effective, and the squid have already shifted to a more active pattern of movement characteristic of the night-time period.

  13. High-sensitivity SQUIDs with dispersive readout for scanning microscopy

    NASA Astrophysics Data System (ADS)

    Mol, J. M.; Foroughi, F.; Arps, J.; Kammerloher, E.; Bethke, P.; Gibson, G. W., Jr.; Fung, Y. K. K.; Klopfer, B.; Nowack, K.; Kratz, P. A.; Huber, M. E.; Moler, K. A.; Kirtley, J. R.; Bluhm, H.

    2014-03-01

    In a scanning SQUID microscope, the high magnetic flux sensitivity is utilized to image magnetic properties of sample surfaces. As an alternative to the widely used DC SQUIDs, we present Nb SQUIDs for scanning with dispersive microwave readout, featuring significantly higher bandwidth and sensitivity. An on-chip shunt capacitor in parallel with the junction and flux pickup loops forms an LC resonator whose resonance depends on the flux in the SQUID. The readout utilizes a phase-sensitive detection of the reflected drive signal at the SQUID's resonance frequency. Highest sensitivities are achieved by making use of the inherent nonlinearity of the device at high excitation powers. We present a study of the characteristics and noise measurements of our sensors at 4 K. Extrapolations from our results to 300 mK indicate that flux sensitivities as low as 50 nΦ0Hz- 1 / 2 could be possible. Using high-resolution lithography, our sensors promise sub-micron spatial resolution. Integrated into a scanning microscope, they will provide a powerful tool for the study of weak magnetic effects and quantum coherent phenomena. This work was supported by NSF IMR-MIP grant No. 0957616 and the Alfried Krupp von Bohlen und Halbach - Foundation.

  14. Calibration of SQUID vector magnetometers in full tensor gradiometry systems

    NASA Astrophysics Data System (ADS)

    Schiffler, M.; Queitsch, M.; Stolz, R.; Chwala, A.; Krech, W.; Meyer, H.-G.; Kukowski, N.

    2014-08-01

    Measurement of magnetic vector or tensor quantities, namely of field or field gradient, delivers more details of the underlying geological setting in geomagnetic prospection than a scalar measurement of a single component or of the scalar total magnetic intensity. Currently, highest measurement resolutions are achievable with superconducting quantum interference device (SQUID)-based systems. Due to technological limitations, it is necessary to suppress the parasitic magnetic field response from the SQUID gradiometer signals, which are a superposition of one tensor component and all three orthogonal magnetic field components. This in turn requires an accurate estimation of the local magnetic field. Such a measurement can itself be achieved via three additional orthogonal SQUID reference magnetometers. It is the calibration of such a SQUID reference vector magnetometer system that is the subject of this paper. A number of vector magnetometer calibration methods are described in the literature. We present two methods that we have implemented and compared, for their suitability of rapid data processing and integration into a full tensor magnetic gradiometry, SQUID-based, system. We conclude that the calibration routines must necessarily model fabrication misalignments, field offset and scale factors, and include comparison with a reference magnetic field. In order to enable fast processing on site, the software must be able to function as a stand-alone toolbox.

  15. Mobile HTS SQUID System for Nondestructive Evaluation of Aircraft Structures

    NASA Astrophysics Data System (ADS)

    Krause, Hans-Joachim; Hohmann, Rainer; Grueneklee, Michael; Zhang, Yi; Braginski, Alex I.

    1997-03-01

    For the detection of deep-lying flaws in aircraft structures, a mobile eddy-current system is being developed in conjunction with a high-temperature superconductor (Yba_2Cu_3O_7) thin-film HTS SQUID gradiometer. The challenge is to operate the SQUID sensor during movement in strong ambient fields, independent of orientation. A planar rf double hole gradiometer with a gradient sensitivity of 500 fT/(cm √Hz) was designed for that purpose. Two different cooling concepts were successfully implemented: the SQUID operation in the vacuum region of a lightweight nitrogen cryostat, constructed for operation in any orientation, and the use of a commercial Joule-Thomson cryocooler for liquid-nitrogen-free SQUID cooling. With a SQUID integration scheme using a sapphire cold finger, motion-related additional noise is nearly eliminated. Using a system equipped with a differential eddy current excitation, two-dimensional scans were performed to find fatigue cracks and corrosion pits hidden below several layers of aluminum. For demonstration in the Lufthansa maintenance facility at Frankfurt Airport, the system was used to detect flaws in aircraft wheels. Work in progress includes developing longer base gradiometers for detection of deep flaws.

  16. Eddy current nondestructive material evaluation based on HTS SQUIDs

    NASA Astrophysics Data System (ADS)

    Mück, M.; Kreutzbruck, M. v.; Baby, U.; Tröll, J.; Heiden, C.

    1997-08-01

    High Temperature Superconductor (HTS) Superconducting Quantum Interference Devices (SQUIDs) are promising sensors for applications in eddy current nondestructive evaluation (NDE). Due to their high field sensitivity at low frequencies, they are especially suitable for applications, where a large penetration depth is required. We have investigated two different SQUID-based NDE systems, one of which is optimised for testing felloes of aircraft wheels. The second system allows for testing planar structures using a motorised x-y-stage, which moves the cryostat above the planar samples. As sensors 3 GHz rf SQUIDs made from YBCO were used, having a field noise of about 1 pT/√Hz. This results in a dynamic range of our SQUID system of about 155 dB/√Hz. In most cases, the SQUIDs have been cooled by immersing them in liquid nitrogen. We have however also developed a cryosystem, which allows for cooling the sensors by a Ne-gas flow. In planar test structures we could detect flaws with lengths of 10 mm, having a height of 0.6 mm in a depth of 13 mm. In aircraft felloes, flaws located at the inner surface of the felloe (thickness 8 mm) were easily detectable despite a high static background field of up to 0.5 G caused by ferromagnetic structures inside the felloe. For flaws in a depth of 5 mm, the spatial resolution of both systems was about 8 mm without applying image postprocessing.

  17. Effect of neon plasma pre-irradiation on surface morphology and deuterium retention of tungsten

    NASA Astrophysics Data System (ADS)

    Cheng, L.; De Temmerman, G.; Zeijlmans van Emmichoven, P. A.; Ji, G.; Zhou, H. B.; Wang, B.; Yuan, Y.; Zhang, Y.; Lu, G. H.

    2015-08-01

    Neon and deuterium plasma irradiation of polycrystalline tungsten targets have been performed at high fluxes of ∼1024 ions m-2 s-1 to study the interaction of neon with tungsten and the influence of neon on deuterium retention. Tungsten exposure to neon plasma leads to the formation of wavy nanostructures on the surface. Subsequent exposure to high-flux deuterium plasma leads to blister formation of micrometer size on top of the wavy structures. The total deuterium retention is decreased by neon pre-irradiation for all surface temperatures used in the present experiments. It is suggested that a barrier of trapped Ne is formed that interrupts the D transport and reduces D retention.

  18. Atomistic simulations of tungsten surface evolution under low-energy neon implantation

    NASA Astrophysics Data System (ADS)

    Backman, Marie; Hammond, Karl D.; Sefta, Faiza; Wirth, Brian D.

    2016-04-01

    Tungsten is a candidate material for the divertor of fusion reactors, where it will be subject to a high flux of particles coming from the fusion plasma as well as a significant heat load. Under helium plasma exposure in fusion-reactor-like conditions, a nanostructured morphology is known to form on the tungsten surface in certain temperature and incident energy ranges, although the formation mechanism is not fully established. A recent experimental study (Yajima et al 2013 Plasma Sci. Technol. 15 282-6) using neon or argon exposure did not produce similar nanostructure. This article presents molecular dynamics simulations of neon implantation in tungsten aimed at investigating the surface evolution and elucidating the role of noble gas mass in fuzz formation. In contrast to helium, neon impacts can sputter both tungsten and previously implanted neon atoms. The shorter range of neon ions, along with sputtering, limit the formation of large bubbles and likely prevents nanostructure formation.

  19. 50 CFR 648.26 - Mackerel, squid, and butterfish possession restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Mackerel, squid, and butterfish... UNITED STATES Management Measures for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.26 Mackerel, squid, and butterfish possession restrictions. (a) Atlantic mackerel. (1) A vessel must be...

  20. 50 CFR 648.26 - Mackerel, squid, and butterfish possession restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Mackerel, squid, and butterfish... UNITED STATES Management Measures for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.26 Mackerel, squid, and butterfish possession restrictions. (a) Atlantic mackerel. (1) A vessel must be...

  1. 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

    ... Mackerel, Squid, and Butterfish (MSB) Fishery Management Plan (FMP) (75 FR 11441, March 11, 2010) as a... United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 7 AGENCY... on the longfin squid fishery from a catch cap to a discard cap in Framework Adjustment 7 to...

  2. 50 CFR 648.26 - Mackerel, squid, and butterfish possession restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Mackerel, squid, and butterfish... UNITED STATES Management Measures for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.26 Mackerel, squid, and butterfish possession restrictions. (a) Atlantic mackerel. (1) A vessel must be...

  3. 50 CFR 648.23 - Mackerel, squid, and butterfish gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... fishery. Owners or operators of otter trawl vessels possessing 2,500 lb (1.13 mt) or more of butterfish...) Longfin squid fishery. Owners or operators of otter trawl vessels possessing longfin squid harvested in or... constriction. Owners or operators of otter trawl vessels fishing for and/or possessing longfin squid shall...

  4. Neon Isotope Fractionation in Ice Cores at Close-Off Depth

    NASA Astrophysics Data System (ADS)

    Liang, C.; Severinghaus, J. P.

    2015-12-01

    Analyzing trapped air bubbles in glacial ice is a well-established and useful method to reconstruct past atmospheric gas concentrations. However, trapped gas composition can be affected by fractionation during the closure of the air bubbles, complicating the reconstruction. Gases such as dioxygen (O2) and dihydrogen (H2) are known to leak out of the bubbles by permeation through the ice lattice at the close-off depth,where firn turns into ice. This process also can cause isotope fractionation, which obscures the past atmospheric isotope ratios in air bubbles in glacial ice. In order to establish the most accurate measurements of past atmospheric content, we need very detailed understanding of the permeation leakage mechanism in order to establish possible corrections. In this study, we propose the use of neon stable isotopes (neon-22 and neon-20) to place constraints on the mechanism of permeation leakage. Neon isotopes are an ideal system to explore because neon has a constant atmospheric isotope ratio, and thus only is affected by close-off fractionation. Neon permeation occurs via velocity-dependent hopping between sites within the ice lattice, because the neon atom is smaller than the critical size (3.6 Å) of the opening in the lattice. Theory predicts that neon isotope fractionation will occur due to the lower velocity of the heavier isotope, but this has never been experimentally verified and the theory is unable to quantitatively predict the magnitude of the fractionation. We will present the first results of high-precision neon isotope (22Ne/20Ne) measurements made in air pumped from the firm-to-ice transition in the Greenland Ice Sheet, where actively closing air bubbles drive permeation leakage. By measuring this natural neon isotope fractionation, we hope to learn about the mass dependence of the leakage mechanism and develop a more quantitative theory that is generalizable to biogeochemically- and climatically-active gases.

  5. 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.

  6. 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.

  7. NMR/MRI with hyperpolarized gas and high Tc SQUID

    DOEpatents

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

    2000-01-01

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

  8. Fabrication and characterization of hybrid Nb-YBCO dc SQUIDs

    SciTech Connect

    Frack, E.K.; Drake, R.E.; Patt, R.; Radparvar, M. )

    1991-03-01

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

  9. Electron Scattering from Neon Via Effective Range Theory

    NASA Astrophysics Data System (ADS)

    Fedus, Kamil

    2014-12-01

    Elastic cross-sections for electron scattering on neon from 0 energy up to 16 eV are analyzed by an analytical approach to the modified effective range theory (MERT). It is shown that energy and angular variations of elastic differential, integral and momentum transfer cross-sections can be accurately parameterized by six MERT coefficients up to the energy threshold for the first Feshbach resonance. MERT parameters are determined empirically by numerical comparison with large collection of available experimental data of elastic total (integral) cross-sections. The present analysis is validated against numerous electron beams and swarm experiments. The comparison of derived MERT parameters with those found for other noble gases, helium, argon and krypton, is done. The derived scattering length (for the s-partial wave) in neon, 0.227 a 0, agrees well with recent theories; it is small but, differently from Ar and Kr, still positive. Analogue parameters for the p-wave and the d-wave are negative and positive respectively for all the four gases compared.

  10. Infrared spectra of small molecular ions trapped in solid neon

    SciTech Connect

    Jacox, Marilyn E.

    2015-01-22

    The infrared spectrum of a molecular ion provides a unique signature for that species, gives information on its structure, and is amenable to remote sensing. It also serves as a comparison standard for refining ab initio calculations. Experiments in this laboratory trap molecular ions in dilute solid solution in neon at 4.2 K in sufficient concentration for observation of their infrared spectra between 450 and 4000 cm{sup !1}. Discharge-excited neon atoms produce cations by photoionization and/or Penning ionization of the parent molecule. The resulting electrons are captured by other molecules, yielding anions which provide for overall charge neutrality of the deposit. Recent observations of ions produced from C{sub 2}H{sub 4} and BF{sub 3} will be discussed. Because of their relatively large possibility of having low-lying excited electronic states, small, symmetric molecular cations are especially vulnerable to breakdown of the Born-Oppenheimer approximation. Some phenomena which can result from this breakdown will be discussed. Ion-molecule reaction rates are sufficiently high that in some systems absorptions of dimer cations and anions are also observed. When H{sub 2} is introduced into the system, the initially-formed ion may react with it. Among the species resulting from such ion-molecule reactions that have recently been studied are O{sub 4}{sup +}, NH{sub 4}{sup +}, HOCO{sup +}, and HCO{sub 2}{sup !}.

  11. Helium-neon laser treatment transforms fibroblasts into myofibroblasts.

    PubMed Central

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

    1990-01-01

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

  12. An accurate model potential for alkali neon systems.

    PubMed

    Zanuttini, D; Jacquet, E; Giglio, E; Douady, J; Gervais, B

    2009-12-01

    We present a detailed investigation of the ground and lowest excited states of M-Ne dimers, for M=Li, Na, and K. We show that the potential energy curves of these Van der Waals dimers can be obtained accurately by considering the alkali neon systems as one-electron systems. Following previous authors, the model describes the evolution of the alkali valence electron in the combined potentials of the alkali and neon cores by means of core polarization pseudopotentials. The key parameter for an accurate model is the M(+)-Ne potential energy curve, which was obtained by means of ab initio CCSD(T) calculation using a large basis set. For each MNe dimer, a systematic comparison with ab initio computation of the potential energy curve for the X, A, and B states shows the remarkable accuracy of the model. The vibrational analysis and the comparison with existing experimental data strengthens this conclusion and allows for a precise assignment of the vibrational levels. PMID:19968334

  13. Infrared spectra of small molecular ions trapped in solid neon

    NASA Astrophysics Data System (ADS)

    Jacox, Marilyn E.

    2015-01-01

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

  14. Production rates of neon xenon isotopes by energetic neutrons

    NASA Technical Reports Server (NTRS)

    Leich, D. A.; Borg, R. J.; Lanier, V. B.

    1986-01-01

    As a first step in an experimental program to study the behavior of noble gases produced in situ in minerals, a suite of minerals and pure chemicals were irradiated with 14.5 MeV neutrons at LLNL's Rotating Target Neutron Source (RTNS-II) and production rates for noble gases were determined. While neutron effects in meteorites and lunar samples are dominated by low-energy neutron capture, more energetic cosmic-ray secondary neutrons can provide significant depth-dependent contributions to production of cosmogenic nuclides through endothermic reactions such as (n,2n), (n,np), (n,d) and (n,alpha). Production rates for nuclides produced by cosmic-ray secondary neutrons are therefore useful in interpreting shielding histories from the relative abundances of cosmogenic nuclides. Absolute production cross sections were calculated from isotope dilution analyses of NaCl, Mg, CsCl, and Ba(NO3)2 samples, assuming purity, stoichiometry, and quantitative noble gas retention and extraction. Relative production cross sections determined from neon isotopic ratios in the mineral samples were also considered in evaluating the neon production cross sections. Results are presented.

  15. Population dynamics in a metastable neon magneto-optical trap

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  16. Improved Readout Scheme for SQUID-Based Thermometry

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin

    2007-01-01

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

  17. Patch voltage clamp of squid axon membrane.

    PubMed

    Fishman, H M

    1975-12-01

    A small area (patch) of the external surface of a squid axon can be "isolated" electrically from the surrounding bath by means of a pair of concentric glass pipettes. The seawater-filled inner pipette makes contact with the axon and constitutes the external access to the patch. The outer pipette is used to direct flowing sucrose solution over the area surrounding the patch of membrane underlying the inner pipette. Typically, sucrose isolated patches remain in good condition (spike amplitude greater than 90 mV) for periods of approximately one half hour. Patches of axon membrane which had previously been exposed to sucrose solution were often excitable. Membrane survival of sucrose treatment apparently arises from an outflow of ions from the axon and perhaps satellite cells into the interstitial cell space surrounding the exolemma. Estimate of the total access resistance (electrode plus series resistance) to the patch is about 100 komega (7 omega cm2). Patch capacitance ranges from 10-100 pF, which suggests areas of 10(-4) to 10(-5) cm2 and resting patch resistances of 10-100 Momega. Shunt resistance through the interstitial space exposed to sucrose solution, which isolates the patch, is typically 1-2 Momega. These parameters indicate that good potential control and response times can be achieved on a patch. Furthermore, spatial uniformity is demonstrated by measurement of an exoplasmic isopotential during voltage clamp of an axon patch. The method may be useful for other preparations in which limited membrane area is available or in special instances such as in the measurement of membrane conduction noise. PMID:1214276

  18. NEON, Establishing a Standardized Network for Groundwater Observations

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The National Ecological Observatory Network (NEON) is establishing a standardized set of data collection systems comprised of in-situ sensors and observational sampling to obtain data fundamental to the analysis of environmental change at a continental scale. NEON will be collecting aquatic, terrestrial, and atmospheric data using Observatory-wide standardized designs and methods via a systems engineering approach. This approach ensures a wealth of high quality data, data algorithms, and models that will be freely accessible to all communities such as academic researchers, policy makers, and the general public. The project is established to provide 30 years of data which will enable prediction and forecasting of drivers and responses of ecological change at scales ranging from localized responses through regional gradients and up to the continental scale. The Observatory is a distributed system of sites spread across the United States, including Alaska, Hawaii, and Puerto Rico, which is subdivided into 20 statistically unique domains, based on a set of 18 ecologically important parameters. Each domain contains at least one core aquatic and terrestrial site which are located in unmanaged lands, and up to 2 additional sites selected to study domain specific questions such as nitrogen deposition gradients and responses of land use change activities on the ecosystem. Here, we present the development of NEON's groundwater observation well network design and the timing strategy for sampling groundwater chemistry. Shallow well networks, up to 100 feet in depth, will be installed at NEON aquatic sites and will allow for observation of localized ecohydrologic site conditions, by providing basic spatio-temporal near-real time data on groundwater parameters (level, temperature, conductivity) collected from in situ high-resolution instrumentation positioned in each well; and biannual sampling of geochemical and nutrient (N and P) concentrations in a subset of wells for each

  19. 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

  20. TOPICAL REVIEW: Radio-frequency amplifiers based on dc SQUIDs

    NASA Astrophysics Data System (ADS)

    Mück, Michael; McDermott, Robert

    2010-09-01

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

  1. A Simple Quantum Integro-Differential Solver (SQuIDS)

    NASA Astrophysics Data System (ADS)

    Argüelles Delgado, Carlos A.; Salvado, Jordi; Weaver, Christopher N.

    2015-11-01

    Simple Quantum Integro-Differential Solver (SQuIDS) is a C++ code designed to solve semi-analytically the evolution of a set of density matrices and scalar functions. This is done efficiently by expressing all operators in an SU(N) basis. SQuIDS provides a base class from which users can derive new classes to include new non-trivial terms from the right hand sides of density matrix equations. The code was designed in the context of solving neutrino oscillation problems, but can be applied to any problem that involves solving the quantum evolution of a collection of particles with Hilbert space of dimension up to six.

  2. Squid detected NMR and MRI at ultralow fields

    SciTech Connect

    Clarke, John; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

    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.

  3. Squid detected NMR and MRI at ultralow fields

    DOEpatents

    Clarke, John; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

    2006-05-30

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

  4. SQUID detected NMR and MRI at ultralow fields

    DOEpatents

    Clarke, John; McDermott, Robert; Pines, Alexander; Trabesinger, Andreas Heinz

    2006-10-03

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

  5. Squid detected NMR and MRI at ultralow fields

    SciTech Connect

    Clarke, John; Pines, Alexander; McDermott, Robert F.; Trabesinger, Andreas H.

    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.

  6. Swimming dynamics and propulsive efficiency of squids throughout ontogeny.

    PubMed

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

    2008-12-01

    Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures, whereas juveniles and adults operate at higher Re and generally have more streamlined bodies, larger fins, and relatively small funnel apertures. These morphological changes and varying flow conditions affect swimming performance in squids. To determine how swimming dynamics and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV) and kinematic data were collected from an ontogenetic range of long-finned squid Doryteuthis pealeii and brief squid Lolliguncula brevis swimming in a holding chamber or water tunnel (Re = 20-20 000). Jet and fin wake bulk properties were quantified, and propulsive efficiency was computed based on measurements of impulse and excess kinetic energy in the wakes. Paralarvae relied predominantly on a vertically directed, high frequency, low velocity jet as they bobbed up and down in the water column. Although some spherical vortex rings were observed, most paralarval jets consisted of an elongated vortical region of variable length with no clear pinch-off of a vortex ring from the trailing tail component. Compared with paralarvae, juvenile and adult squid exhibited a more diverse range of swimming strategies, involving greater overall locomotive fin reliance and multiple fin and jet wake modes with better defined vortex rings. Despite greater locomotive flexibility, jet propulsive efficiency of juveniles/adults was significantly lower than that of paralarvae, even when juvenile/adults employed their highest efficiency jet mode involving the production of periodic isolated vortex rings with each jet pulse. When the fins were considered together with the jet for several

  7. Common trends in northeast Atlantic squid time series

    NASA Astrophysics Data System (ADS)

    Zuur, A. F.; Pierce, G. J.

    2004-06-01

    In this paper, dynamic factor analysis is used to estimate common trends in time series of squid catch per unit effort in Scottish (UK) waters. Results indicated that time series of most months were related to sea surface temperature measured at Millport (UK) and a few series were related to the NAO index. The DFA methodology identified three common trends in the squid time series not revealed by traditional approaches, which suggest a possible shift in relative abundance of summer- and winter-spawning populations.

  8. Application of squids in the Iwate create project

    NASA Astrophysics Data System (ADS)

    Yoshizawa, M.; He, D. F.; Nakai, K.; Kobayashi, K.; Nakamura, Y.; Yaegashi, M.; Ito, M.; Yashiro, H.; Daibo, M.; Simizu, T.; Uchikawa, Y.; Noto, K.

    2005-10-01

    We have developed a 64-channel magnetocardiograph (MCG) system for the diagnosis of heart disease. The MCG is characterized by its display of a unique three-dimensional image of bio-currents flowing inside the human body. The outline of the heart can be displayed without use of MRI. A mobile SQUID-based non-distractive evaluation apparatus was realized by the active shielding technique. The system can offer information from beneath the surface of the specimen by using a saw-wave excitation method. This mobile technology enables us to inspect ferromagnetic materials, whose high magnetic field rules out the use of a conventional SQUID apparatus near them.

  9. Sound radiation around a flying fly

    NASA Astrophysics Data System (ADS)

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

    2005-07-01

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

  10. Development of a Two-Dimensional Micro-SQUID Array for Investigation of Magnetization Spatial Distribution

    NASA Astrophysics Data System (ADS)

    Sakuma, Daisuke; Shinozaki, Tomoya; Nago, Yusuke; Ishiguro, Ryosuke; Kashiwaya, Satoshi; Nomura, Shintaro; Kono, Kimitoshi; Takayanagi, Hideaki

    2016-05-01

    We developed a two-dimensional array of superconducting quantum interference devices (SQUIDs) for investigation of fine spatial distribution of magnetization in superconducting Sr2RuO4. Micrometer-sized SQUIDs based on homogeneously formed Al/AlOx/Al tunnel-type Josephson junctions were fabricated using shadow evaporation technique. Unnecessary electrodes formed by the shadow evaporation were removed by inductively coupled plasma reactive ion etching, in order to realize a dense array of SQUIDs. We measured the magnetic modulation of the maximum Josephson current of each SQUID in the array and evaluated the interaction among the SQUIDs.

  11. Two Methods for a First Order Hardware Gradiometer Using Two HTS SQUID's

    SciTech Connect

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

    1998-09-15

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

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

    SciTech Connect

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

    1998-12-31

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

  13. Observations on the spawning behavior, egg masses and paralarval development of the ommastrephid squid Todarodes pacificus in a laboratory mesocosm.

    PubMed

    Puneeta, Pandey; Vijai, Dharmamony; Yoo, Hae-Kyun; Matsui, Hajime; Sakurai, Yasunori

    2015-12-01

    The spawning behavior of ommastrephid squids has never been observed under natural conditions. Previous laboratory observations of Japanese flying squid (Todarodes pacificus) suggest that pre-spawning females might rest on the continental shelf or slope before they ascend above the pycnocline to spawn, and that the egg masses might settle in the pycnocline. Here, two mesocosm experiments were conducted in a 300 m(3) tank that was 6 m deep to investigate this hypothesis. In the first experiment, a thermocline (2.5-3.5 m) was established in the tank by creating a thermally stratified (17-22°C) water column. In the second experiment, the temperature was uniform (22°C) at all depths. Prior to spawning, females did not rest on the tank floor. In the stratified water column, egg masses remained suspended in the thermocline, but in an unstratified water column, they settled on the tank bottom, collapsed and were infested by microbes, resulting in abnormal or nonviable embryos. Eleven females spawned a total of 18 egg masses (17-80 cm in diameter), indicating that females can spawn more than once when under stress. Paralarvae hatched at stage 30/31 and survived for up to 10 days, allowing us to observe the most advanced stage of paralarvae in captivity. Paralarvae survived after consumption of the inner yolk, suggesting they might have fed in the tank. PMID:26632456

  14. 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

  15. 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.

    2015-08-01

    The triple-point temperature of neon, , 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 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 , 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 measurements with the neon gases due to the nature of the open-cell type system. Therefore, the difference in 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.

  16. Ever Fly a Tetrahedron?

    ERIC Educational Resources Information Center

    King, Kenneth

    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. Put simply, a kite is an airfoil surface that flies when the forces of lift and thrust are greater than the forces of…

  17. Activation of fly ash

    DOEpatents

    Corbin, David R.; Velenyi, Louis J.; Pepera, Marc A.; Dolhyj, Serge R.

    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.

  18. Activation of fly ash

    DOEpatents

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

    1986-08-19

    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.

  19. A Flying Summer Camp

    ERIC Educational Resources Information Center

    Mercurio, Frank X.

    1975-01-01

    Describes a five-day summer camp which provided 12 children, ages 9-14, with a complete flying experience. The training consisted of ground school and one hour actual flying time, including the basics of aircraft control and a flight prepared and executed by the students. (MLH)

  20. 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

  1. 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) μK when using neon of ‘natural’ isotopic composition or to 30 μK 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.

  2. Imaging of the structure of the argon and neon dimer, trimer, and tetramer.

    PubMed

    Ulrich, B; Vredenborg, A; Malakzadeh, A; Schmidt, L Ph H; Havermeier, T; Meckel, M; Cole, K; Smolarski, M; Chang, Z; Jahnke, T; Dörner, R

    2011-06-30

    We Coulomb explode argon and neon dimers, trimers, and tetramers by multiple ionization in an ultrashort 800 nm laser pulse. By measuring all momentum vectors of the singly charged ions in coincidence, we determine the ground state nuclear wave function of the dimer, trimer, and tetramer. Furthermore we retrieve the bond angles of the trimer in position space by applying a classical numerical simulation. For the argon and neon trimer, we find a structure close to the equilateral triangle. The width of the distribution around the equilateral triangle is considerably wider for neon than for argon. PMID:21413773

  3. Relationship between tissue structural collapse and disappearance of flesh transparency during postmortem changes in squid mantles.

    PubMed

    Kugino, Mutsuko; Kugino, Kenji; Tamura, Tomoko; Asakura, Tomiko

    2009-01-01

    This study evaluated the relationship between squid flesh transparency and muscle tissue microstructure. Squid mantle muscle was stored at 4 degrees C after being transported for 2 h by 4 different transportation methods used commonly in Japan (Group 1: live squid packed in ice-cold seawater; Group 2: live squid packed at 4 degrees C; Group 3: squid killed immediately after harvest and packed at 4 degrees C; Group 4: live squid packed in a fish tank containing seawater). Parameters of muscle tissue transparency were measured by an image analysis of digital images of squid muscle tissue. The mantle muscle tissue was observed under a transmission electron microscope to determine the postmortem structural changes at the cellular level. The ATP content of muscle tissue and rupture energy of squid flesh were also measured. As a result, the transparency of squid flesh and the ATP content of the muscles showed the same pattern of change in degree as time passed. The values of these parameters were highest in the group of squid killed immediately followed in order by those transported live, the refrigerated squid, and squid stored in ice-cold seawater. The mantle muscle tissue started to lose its transparency when the ATP in the muscle tissue started to decline. Disintegration of squid muscle tissue structure at the cellular level during storage under refrigeration for 24 h (4 degrees C) was observed in all methods of transportation. This suggested that destruction of the squid muscle tissue structure by autolysis is remarkably fast. The muscle tissue structure disintegrates due to decomposition of the muscle proteins, and muscle transparency is lost because the entire muscle develops a mixed coarse-minute structure. PMID:20492111

  4. Bias Reversal Technique in SQUID Bootstrap Circuit (SBC) Scheme

    NASA Astrophysics Data System (ADS)

    Rong, Liangliang; Zhang, Yi; Zhang, Guofeng; Wu, Jun; Dong, Hui; Qiu, Longqing; Xie, Xiaoming; Offenhüusser, Andreas

    Recently, a SQUID direct readout scheme called voltage-biased SQUID Bootstrap Circuit (SBC) is introduced to reduce preamplifier noise contribution. In this paper, we describe a concept of SBC with bias reversal technique which can suppress SQUID intrinsic 1/f noise. When applying a symmetrically rectangular voltage across SBC, two I-Φ characteristics appear at the amplifier output. In order to return to one I - Φ curve, a demodulation technique is required. Because of the asymmetry of typical SBC I-Φ curve, the demodulation method is realized by using a flux compensation of one half Φ0 flux shift. The output signal is then filtered and returned to one I-Φ curve for ordinary FLL readout. It was found, the reversal frequency fR can be dramatically enhanced when using a preamplifier consisting of two operational amplifiers. A planar Nb SQUID magnetometer with a loop-inductance of 350 pH, fR =50 kHz and a second order low pass filter with 10 kHz cut off frequency was employed in our experiment. Results prove the feasibility of SBC bias reversal method. Comparative experiment on noise performance will be carried out in further studies.

  5. Scanning SQUID-on-tip microscopy of vortex matter

    NASA Astrophysics Data System (ADS)

    Anahory, Yonathan; Embon, Lior; Vasyukov, Denis; Cuppens, Jo; Lachman, Ella; Halbertal, Dorri; Yaakobi, Elad; Uri, Aviram; Myasoedov, Yuri; Rappaport, Michael L.; Huber, Martin E.; Zeldov, Eli; Weizmann Institute of Science Team; University of Colorado at Denver Team

    2014-03-01

    We present a scanning nanoSQUID microscope with record spatial resolution, spin sensitivity, and operating magnetic fields for the study of vortex matter. The key element of the microscope is the SQUID-on-tip (SOT) device, which is fabricated by pulling a quartz tube into a sharp pipette, followed by three steps of thermal evaporation of a thin superconducting film onto the sides and the apex of the pipette. The devices operate at 4.2 K in applied fields of up to 1T and can be made with diameters down to 50 nm. The SQUIDs-on-tip display an extremely low flux noise of Φn = 50 nΦ0/Hz1/2 and corresponding spin sensitivity of better than 1 μB/Hz1/2, which is about two orders of magnitude improvement over any previous SQUID. Using this new tool we have investigated static and dynamic behavior of vortices in superconducting Pb films. By driving ac and dc transport current we can study vortex displacement and the vortex potential landscape with sub-atomic precision. Azrieli and Minerva Foundation, FQRNT(Quebec), ERC (Europe)

  6. A 128 Multiplexing Factor Time-Domain SQUID Multiplexer

    NASA Astrophysics Data System (ADS)

    Prêle, D.; Voisin, F.; Piat, M.; Decourcelle, T.; Perbost, C.; Chapron, C.; Rambaud, D.; Maestre, S.; Marty, W.; Montier, L.

    2016-01-01

    A cryogenic 128:1 Time-Domain Multiplexer (TDM) has been developed for the readout of kilo-pixel Transition Edge Sensor (TES) arrays dedicated to the Q&U Bolometric Interferometer for Cosmology (QUBIC) instrument which aims to measure the B-mode polarization of the Cosmic Microwave Background. Superconducting QUantum Interference Devices (SQUIDs) are usually used to read out TESs. Moreover, SQUIDs are used to build TDM by biasing sequentially the SQUIDs connected together—one for each TES. In addition to this common technique which allows a typical 32 multiplexing factor, a cryogenic integrated circuit provides a 4:1 second multiplexing stage. This cryogenic integrated circuit is one of the original part of our TDM achieving an unprecedented 128 multiplexing factor. We present these two dimension TDM stages: topology of the SQUID multiplexer, operation of the cryogenic integrated circuit, and integration of the full system to read out a TES array dedicated to the QUBIC instrument. Flux-locked loop operation in multiplexed mode is also discussed.

  7. A unique advantage for giant eyes in giant squid.

    PubMed

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

    2012-04-24

    Giant and colossal deep-sea squid (Architeuthis and Mesonychoteuthis) have the largest eyes in the animal kingdom [1, 2], but there is no explanation for why they would need eyes that are nearly three times the diameter of those of any other extant animal. Here we develop a theory for visual detection in pelagic habitats, which predicts that such giant eyes are unlikely to evolve for detecting mates or prey at long distance but are instead uniquely suited for detecting very large predators, such as sperm whales. We also provide photographic documentation of an eyeball of about 27 cm with a 9 cm pupil in a giant squid, and we predict that, below 600 m depth, it would allow detection of sperm whales at distances exceeding 120 m. With this long range of vision, giant squid get an early warning of approaching sperm whales. Because the sonar range of sperm whales exceeds 120 m [3-5], we hypothesize that a well-prepared and powerful evasive response to hunting sperm whales may have driven the evolution of huge dimensions in both eyes and bodies of giant and colossal squid. Our theory also provides insights into the vision of Mesozoic ichthyosaurs with unusually large eyes. PMID:22425154

  8. High-Resolution Displacement Sensor Using a SQUID Array Amplifier

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  9. 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.

  10. Vampire squid: detritivores in the oxygen minimum zone.

    PubMed

    Hoving, Hendrik J T; Robison, Bruce H

    2012-11-22

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

  11. Efficiency of the SQUID ratchet driven by external current

    NASA Astrophysics Data System (ADS)

    Spiechowicz, J.; Łuczka, J.

    2015-02-01

    We study theoretically the efficiency of an asymmetric superconducting quantum interference device (SQUID) which is constructed as a loop with three capacitively and resistively shunted Josephson junctions. Two junctions are placed in series in one arm and the remaining one is located in the other arm. The SQUID is threaded by an external magnetic flux and driven by an external current of both constant (dc) and time periodic (ac) components. This system acts as a nonequilibrium ratchet for the dc voltage across the SQUID with the external current as a source of energy. We analyze the power delivered by the external current and find that it strongly depends on thermal noise and the external magnetic flux. We explore a space of the system parameters to reveal a set for which the SQUID efficiency is globally maximal. We detect the intriguing feature of the thermal noise enhanced efficiency and show how the efficiency of the device can be tuned by tailoring the external magnetic flux.

  12. A 128 Multiplexing Factor Time-Domain SQUID Multiplexer

    NASA Astrophysics Data System (ADS)

    Prêle, D.; Voisin, F.; Piat, M.; Decourcelle, T.; Perbost, C.; Chapron, C.; Rambaud, D.; Maestre, S.; Marty, W.; Montier, L.

    2016-07-01

    A cryogenic 128:1 Time-Domain Multiplexer (TDM) has been developed for the readout of kilo-pixel Transition Edge Sensor (TES) arrays dedicated to the Q&U Bolometric Interferometer for Cosmology (QUBIC) instrument which aims to measure the B-mode polarization of the Cosmic Microwave Background. Superconducting QUantum Interference Devices (SQUIDs) are usually used to read out TESs. Moreover, SQUIDs are used to build TDM by biasing sequentially the SQUIDs connected together—one for each TES. In addition to this common technique which allows a typical 32 multiplexing factor, a cryogenic integrated circuit provides a 4:1 second multiplexing stage. This cryogenic integrated circuit is one of the original part of our TDM achieving an unprecedented 128 multiplexing factor. We present these two dimension TDM stages: topology of the SQUID multiplexer, operation of the cryogenic integrated circuit, and integration of the full system to read out a TES array dedicated to the QUBIC instrument. Flux-locked loop operation in multiplexed mode is also discussed.

  13. High-Tc SQUID magnetometer system with active cancellation

    NASA Astrophysics Data System (ADS)

    Kuriki, S.; Oyama, H.; Hayashi, A.; Washio, T.; Fujita, M.; Hirata, Y.

    2002-05-01

    Recent developments of high-Tc SQUIDs have enabled high sensitivity magnetometers to be used in wide range of places, such as laboratory and outdoor fields. At the early stage of developing multichannel system for measurement of magnetocardiogram (MCG) in clinical application, we have fabricated a single channel high-Tc SQUID magnetometer system. The system includes a direct-coupled SQUID with slot structure, a simple magnetically shielded room (MSR), and some active compensation electronics for the purpose of reducing various environmental field noises. A novel active noise cancellation was made by using a combination of a normal conducting detection coil that was horizontally wound in the middle height of the MSR, and two compensation coils that were wound at the top and bottom of the MSR. In addition, adaptive noise cancellation was supplemented by means of adaptive digital filter that was implemented in a digital signal processor. A total noise field attenuation of 50-60 dB was attained at 0.5-100 Hz. Low noise signals from the human heart were measured with a high-Tc SQUID in the noise reduced space in the MSR.

  14. A YBCO RF-SQUID magnetometer and its applications

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  15. The infrared spectrum of HOOH+ trapped in solid neon.

    PubMed

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

    2012-10-14

    When a Ne:H(2)O(2) mixture is codeposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, three new, photosensitive absorptions appear which can be assigned to the three infrared-active vibrational fundamentals of trans-HOOH(+). When the Ne:H(2)O(2) deposition system is pretreated with the vapors of D(2)O, the product absorptions include new peaks which can be attributed to vibrational fundamentals of trans-HOOD(+) and trans-DOOD(+). Density functional calculations of the vibrational fundamentals of the three hydrogen peroxide cation isotopologues support the proposed assignments. Broad, photosensitive product absorptions also appear near the positions of vibrational transitions of O(3)(-), and may be contributed by a weakly bound complex of that species with H(2)O. PMID:23061846

  16. Helium and neon abundances and compositions in cometary matter.

    PubMed

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

    2008-01-01

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

  17. Attainable superheat of argon-helium, argon-neon solutions.

    PubMed

    Baidakov, Vladimir G; Kaverin, Aleksey M; Andbaeva, Valentina N

    2008-10-16

    The method of lifetime measurement has been used to investigate the kinetics of spontaneous boiling-up of superheated argon-helium and argon-neon solutions. Experiments were made at a pressure of p = 1.5 MPa and concentrations up to 0.33 mol% in the range of nucleation rates from 10 (4) to 10 (8) s (-1) m (-3). The homogeneous nucleation regime has been distinguished. With good agreement between experimental data and homogeneous nucleation theory in temperature and concentration dependences of the nucleation rate, a systematic underestimation by 0.25-0.34 K has been revealed in superheat temperatures over the saturated line attained by experiment as compared with theoretical values calculated in a macroscopic approximation. The revealed disagreement between theory and experiment is connected with the dependence of the properties of new-phase nuclei on their size. PMID:18798666

  18. Water depth measurement using an airborne pulsed neon laser system

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.; Frederick, E. B.

    1980-01-01

    The paper presents the water depth measurement using an airborne pulsed neon laser system. The results of initial base-line field test results of NASA airborne oceanographic lidar in the bathymetry mode are given, with water-truth measurements of depth and beam attenuation coefficients by boat taken at the same time as overflights to aid in determining the system's operational performance. The nadir-angle tests and field-of-view data are presented; this laser bathymetry system is an improvement over prior models in that (1) the surface-to-bottom pulse waveform is digitally recorded on magnetic tape, and (2) wide-swath mapping data may be routinely acquired using a 30 deg full-angle conical scanner.

  19. 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 n

  20. Paleointensity of the Martian field from SQUID Microscopy

    NASA Astrophysics Data System (ADS)

    Weiss, B. P.; Fong, L. E.; Lima, E. A.; Baudenbacher, F. J.; Vali, H.

    2005-12-01

    Crustal magnetic anomalies in the southern Martian hemisphere have intensities an order of magnitude larger than typical crustal anomalies on Earth. Two possible explanations for this difference are that compared to the present-day Earth, Mars has either (i) larger amounts of crustal ferromagnetic minerals or (ii) the crust was magnetized by a larger paleofield. ALH84001, the only pre-Amazonian Martian meteorite, possesses a stable magnetization dating to 4 Ga or earlier. Previous paleomagnetic studies with SQUID moment magnetometers on bulk ALH84001 grains have estimated that the paleointensity of the field which magnetized the meteorite was between 0.1-1 times that of the Earth's present field. However, these estimates may be lower limits on the true paleointensity because the orientation of the magnetization in ALH84001 is spatially heterogeneous on the submillimeter scale. This complication could have profound implications for hypothesis (ii) above. Here we first demonstrate that superconducting quantum interference device (SQUID) microscopy can recover the same magnetization intensity and direction of a well characterized modern-day terrestrial basalt as that measured with a 2G Enterprises SQUID moment magnetometer. A SQUID microscope paleointensity analysis of this basalt gives the expected present day field intensity of a few tens of microtesla. We further show that our new high resolution SQUID microscopy study of ALH84001, which has mapped its heterogeneous magnetization with the highest resolution yet (0.1 mm), favors the upper range of previous paleointensity estimates for the 4 Ga Martian paleofield (e.g., within a factor of several of that of the present-day Earth). However, this field, were it dynamo in origin, is still too weak to easily explain the intensity of the Martian magnetic anomalies.

  1. Equation of state of dense neon and krypton plasmas in the partial ionization regime

    SciTech Connect

    Chen, Q. F. Zheng, J.; Gu, Y. J.; Li, Z. G.

    2015-12-15

    The compression behaviors of dense neon and krypton plasmas over a wide pressure-temperature range are investigated by self-consistent fluid variational theory. The ionization degree and equation of state of dense neon and krypton are calculated in the density-temperature range of 0.01–10 g/cm{sup 3} and 4–50 kK. A region of thermodynamic instability is found which is related to the plasma phase transition. The calculated shock adiabat and principal Hugoniot of liquid krypton are in good agreement with available experimental data. The predicted results of shock-compressed liquid neon are presented, which provide a guide for dynamical experiments or numerical first-principle calculations aimed at studying the compression properties of liquid neon in the partial ionization regime.

  2. Neon as a Buffer Gas for a Mercury-Ion Clock

    NASA Technical Reports Server (NTRS)

    Prestage, John; Chung, Sang

    2008-01-01

    A developmental miniature mercury-ion clock has stability comparable to that of a hydrogen-maser clock. The ion-handling components are housed in a sealed vacuum tube, wherein a getter pump is used to maintain the partial vacuum, and the evacuated tube is backfilled with mercury vapor in a buffer gas. Neon was determined to be the best choice for the buffer gas: The pressure-induced frequency pulling by neon was found to be only about two-fifths of that of helium. Furthermore, because neon diffuses through solids much more slowly than does helium, the operational lifetime of a tube backfilled with neon could be considerably longer than that of a tube backfilled with helium.

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

    SciTech Connect

    Saprykin, E. G.; Sorokin, V. A. Shalagin, A. M.

    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.

  4. Experimental separation of virtual photon exchange and electron transfer in interatomic coulombic decay of neon dimers.

    PubMed

    Jahnke, T; Czasch, A; Schöffler, M; Schössler, S; Käsz, M; Titze, J; Kreidi, K; Grisenti, R E; Staudte, A; Jagutzki, O; Schmidt, L Ph H; Weber, Th; Schmidt-Böcking, H; Ueda, K; Dörner, R

    2007-10-12

    We investigate the interatomic Coulombic decay (ICD) of neon dimers following photoionization with simultaneous excitation of the ionized atom (shakeup) in a multiparticle coincidence experiment. We find that, depending on the parity of the excited state, which determines whether ICD takes place via virtual dipole photon emission or overlap of the wave functions, the decay happens at different internuclear distances, illustrating that nuclear dynamics heavily influence the electronic decay in the neon dimer. PMID:17995162

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

    PubMed

    Monteferrante, Michele; Bonella, Sara; Ciccotti, Giovanni

    2013-02-01

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

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

    DOEpatents

    Laverman, Royce J.; Lai, Ban-Yen

    1993-01-01

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

  7. The origin of the neon isotopes in chondrites and on Earth

    NASA Astrophysics Data System (ADS)

    Moreira, Manuel; Charnoz, Sébastien

    2016-01-01

    We discuss the origin of the neon isotopic signatures in chondrites and in the terrestrial mantle. There are two primary possible origins for neon in the Earth's mantle. One origin is the dissolution of a dense primordial atmosphere with a solar composition of 20Ne/22Ne >13.4 into the mantle in a possible magma ocean stage during Earth's accretion. The second origin, developed in this study, is that mantle neon was already in Earth's parent bodies because of refractory grain irradiation by solar wind. We propose that solar wind implantation occurred early on dust within the accretion disk to allow such irradiation. Because solar wind implantation fractionates neon isotopes, the heavier isotopes are implanted deeper than the lighter ones because of different kinetic energies, and the process of implantation, if coupled with sputtering, leads to a steady state neon isotopic ratio (20Ne/22Ne ∼12.7) that is similar to what is observed in mantle-derived rocks (12.5-12.9), lunar soil grains (∼12.9) and certain gas-rich chondrites from all classes (enstatite, ordinary, rumuruti). Using a dust transport model in a turbulent and irradiated solar nebula, we estimated the equivalent irradiation age of a population of dust particles at three different distances from the sun (0.8, 1, 1.2 AU) and converted these ages into neon concentrations and isotopic ratios. The dust subsequently coagulated to form Earth's parent bodies, which have the mean neon isotopic composition of the irradiated dust (non-irradiated dust is assumed to be free of neon). If this scenario of solar wind implantation coupled with sputtering in the precursors of Earth's parent bodies is correct, it offers a simple alternative to the model of solar nebula gas incorporation by dissolution in a magma ocean.

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

    NASA Astrophysics Data System (ADS)

    Monteferrante, Michele; Bonella, Sara; Ciccotti, Giovanni

    2013-02-01

    We apply the phase integration method for quasiclassical quantum time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011), 10.1080/00268976.2011.619506] to compute the dynamic structure factor of liquid neon. So far the method had been tested only on model systems. By comparing our results for neon with experiments and previous calculations, we demonstrate that the scheme is accurate and efficient also for a realistic model of a condensed phase system showing quantum behavior.

  9. Laser optogalvanic wavelength calibration with a commercial hollow cathode iron - neon discharge lamp

    NASA Technical Reports Server (NTRS)

    Zhu, Xinming; Nur, Abdullahi H.; Misra, Prabhakar

    1994-01-01

    351 optogalvanic transitions have been observed in the 337 - 598 nm wavelength region using an iron - neon hollow cathode discharge lamp and a pulsed tunable dye laser. 223 of these have been identified as transitions associated with neon energy levels. These optogalvanic transitions have allowed, in conjunction with interference fringes recorded concomitantly with an etalon, the calibration of the dye laser wavelength with 0.3/cm accuracy.

  10. [The effect of helium-neon laser radiation on the energy metabolic indices of the myocardium].

    PubMed

    Chizhov, G K; Koval'skaia, N I; Kozlov, V I

    1991-03-01

    It was shown in experiments on white rats, that intravenous and direct myocardium helium-neon laser irradiation leads to the some activation of lactate, glucose-6-phosphate, succinate and reduced NAD degydrogenases. During direct myocardium irradiation these changes are in a less degree. It is suggested that helium-neon laser irradiation displays some active influence on the energy metabolism enzymes of the myocardium, and the mechanisms of this action are discussed. PMID:2054512

  11. A comparison of neon versus helium ion beam induced deposition via Monte Carlo simulations.

    PubMed

    Timilsina, Rajendra; Smith, Daryl A; Rack, Philip D

    2013-03-22

    The ion beam induced nanoscale synthesis of PtCx (where x ∼ 5) using the trimethyl (methylcyclopentadienyl)platinum(IV) (MeCpPt(IV)Me3) precursor is investigated by performing Monte Carlo simulations of helium and neon ions. The helium beam leads to more lateral growth relative to the neon beam because of its larger interaction volume. The lateral growth of the nanopillars is dominated by molecules deposited via secondary electrons in both the simulations. Notably, the helium pillars are dominated by SE-I electrons whereas the neon pillars are dominated by SE-II electrons. Using a low precursor residence time of 70 μs, resulting in an equilibrium coverage of ∼4%, the neon simulation has a lower deposition efficiency (3.5%) compared to that of the helium simulation (6.5%). At larger residence time (10 ms) and consequently larger equilibrium coverage (85%) the deposition efficiencies of helium and neon increased to 49% and 21%, respectively; which is dominated by increased lateral growth rates leading to broader pillars. The nanoscale growth is further studied by varying the ion beam diameter at 10 ms precursor residence time. The study shows that total SE yield decreases with increasing beam diameters for both the ion types. However, helium has the larger SE yield as compared to that of neon in both the low and high precursor residence time, and thus pillars are wider in all the simulations studied. PMID:23449368

  12. 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.

  13. Resonant Frequency Dependence on Outer Diameter of High Tc rf-SQUID

    NASA Astrophysics Data System (ADS)

    Ashizuka, Takuya; Sakai, Akira; Miyato, Yuji; Itozaki, Hideo

    Superconducting quantum interference devices (SQUIDs) have been applied to various magnetic sensing. An rf-SQUID can measure magnetic signals by applying external rf-magnetic field whose frequency is tuned to its resonance. Our rf-SQUID having the outer diameter of 3.5 mm needed a substrate resonator to operate it within the operation frequency range of our using FLL electronics. The designs of the rf-SQUID and the resonator were critical to the resonant frequency and the effective area. In this paper, the outer diameter dependence of the resonant frequency and the effective area were investigated by both the electromagnetic simulations and the experiments. The results showed that the rf-SQUID having the larger outer diameter has the smaller resonant frequency and the larger effective area. The rf-SQUIDs having the larger outer diameter were fabricated according to the simulation results. They could be operated within the operation frequency range even though a resonator was omitted.

  14. Energetics of an rf SQUID Coupled to Two Thermal Reservoirs

    PubMed Central

    Gardas, B.; Łuczka, J.; Ptok, A.; Dajka, J.

    2015-01-01

    We study energetics of a Josephson tunnel junction connecting a superconducting loop pierced by an external magnetic flux (an rf SQUID) and coupled to two independent thermal reservoirs of different temperature. In the framework of the theory of quantum dissipative systems, we analyze energy currents in stationary states. The stationary energy flow can be periodically modulated by the external magnetic flux exemplifying the rf SQUID as a quantum heat interferometer. We also consider the transient regime and identify three distinct regimes: monotonic decay, damped oscillations and pulse-type behavior of energy currents. The first two regimes can be controlled by the external magnetic flux while the last regime is robust against its variation. PMID:26641890

  15. Multi-tone response of Nonlinear rf-SQUID metamaterials

    NASA Astrophysics Data System (ADS)

    Zhang, Daimeng; Trepanier, Melissa; Mukhanov, Oleg; Antonsen, Thomas; Ott, Edward; Anlage, Steven

    We study the multi-tone response over a broad microwave frequency range of a nonlinear superconducting meta-atom and a metamaterial composed of Radio Frequency Superconducting QUantum Interference Devices (rf-SQUIDs). Nonlinearity in the SQUID metamaterial gives rise to large-range tunable resonance via dc/rf magnetic field and temperature, it also results in signal mixing through intermodulation distortion (IMD). Our metamaterial responds to multi-frequency signals and generates strong higher order intermodulation signals in a certain range of applied rf power. However, our meta-atom and metamaterial show a reduced third-order IMD generation around the resonance, which is unusual for typical nonlinear systems. The numerical simulation predicts the same IMD gap feature as in experiment. A comprehensive analytical model is applied to explain the phenomena, and methods to enhance, or reduce, intermodulation levels are explored. This work is supported by the NSF-GOALI and OISE programs through Grant # ECCS-1158644, and CNAM.

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

    NASA Astrophysics Data System (ADS)

    Yan, Mingyan; Li, Bafang; Zhao, Xue

    2009-06-01

    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 muscle fiber. Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were extracted from the skin and characterized. The results of amino acid composition and electrophoretic patterns revealed that ASC and PSC were both type I collagen, containing α1 and α2 chains. FTIR (fourier transform infrared spectroscopy) investigations confirmed the existence of helical arrangements in PSC of squid skin. The denaturation temperature (Td) and shrinkage temperature (Ts) of PSC were 29.4°C and 52.8°C, respectively.

  17. A three-axis SQUID-based absolute vector magnetometer

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz1/2. The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  18. TES Detector Noise Limited Readout Using SQUID Multiplexers

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  19. nanoSQUID operation using kinetic rather than magnetic induction.

    PubMed

    McCaughan, Adam N; Zhao, Qingyuan; Berggren, Karl K

    2016-01-01

    We report on a method of nanoSQUID modulation which uses kinetic inductance rather than magnetic inductance to manip-ulate the internal fluxoid state. We produced modulation using injected current rather than an applied magnetic field. Using this injected current, we were able to observe the triangle-wave shaped modulation of the device critical current which was periodic according to the London fluxoid quantization condition. The measurement results also confirmed that the fluxoid state inside a superconducting loop can be manipulated using primarily kinetic inductance. By using primarily kinetic inductance rather than magnetic inductance, the size of the coupling inductor was reduced by a factor of 10. As a result, this approach may provide a means to reduce the size of SQUID-based superconducting electronics. Additionally, this method provides a convenient way to perform kinetic inductance characterizations of superconducting thin films. PMID:27296586

  20. nSQUID arrays as conveyers of quantum information

    NASA Astrophysics Data System (ADS)

    Deng, Qiang; Averin, D. V.

    2014-12-01

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

  1. nanoSQUID operation using kinetic rather than magnetic induction

    PubMed Central

    McCaughan, Adam N.; Zhao, Qingyuan; Berggren, Karl K.

    2016-01-01

    We report on a method of nanoSQUID modulation which uses kinetic inductance rather than magnetic inductance to manip-ulate the internal fluxoid state. We produced modulation using injected current rather than an applied magnetic field. Using this injected current, we were able to observe the triangle-wave shaped modulation of the device critical current which was periodic according to the London fluxoid quantization condition. The measurement results also confirmed that the fluxoid state inside a superconducting loop can be manipulated using primarily kinetic inductance. By using primarily kinetic inductance rather than magnetic inductance, the size of the coupling inductor was reduced by a factor of 10. As a result, this approach may provide a means to reduce the size of SQUID-based superconducting electronics. Additionally, this method provides a convenient way to perform kinetic inductance characterizations of superconducting thin films. PMID:27296586

  2. Energetics of an rf SQUID Coupled to Two Thermal Reservoirs

    DOE PAGESBeta

    Gardas, B.; Łuczka, J.; Ptok, A.; Dajka, J.

    2015-12-07

    We study energetics of a Josephson tunnel junction connecting a superconducting loop pierced by an external magnetic flux (an rf SQUID) and coupled to two independent thermal reservoirs of different temperature. In the framework of the theory of quantum dissipative systems, we analyze energy currents in stationary states. The stationary energy flow can be periodically modulated by the external magnetic flux exemplifying the rf SQUID as a quantum heat interferometer. Additionally, we consider the transient regime and identify three distinct regimes: monotonic decay, damped oscillations and pulse-type behavior of energy currents. Furthermore, the first two regimes can be controlled bymore » the external magnetic flux while the last regime is robust against its variation.« less

  3. Energetics of an rf SQUID Coupled to Two Thermal Reservoirs

    SciTech Connect

    Gardas, B.; Łuczka, J.; Ptok, A.; Dajka, J.

    2015-12-07

    We study energetics of a Josephson tunnel junction connecting a superconducting loop pierced by an external magnetic flux (an rf SQUID) and coupled to two independent thermal reservoirs of different temperature. In the framework of the theory of quantum dissipative systems, we analyze energy currents in stationary states. The stationary energy flow can be periodically modulated by the external magnetic flux exemplifying the rf SQUID as a quantum heat interferometer. Additionally, we consider the transient regime and identify three distinct regimes: monotonic decay, damped oscillations and pulse-type behavior of energy currents. Furthermore, the first two regimes can be controlled by the external magnetic flux while the last regime is robust against its variation.

  4. Candidate Source of Flux Noise in SQUIDs: Adsorbed Oxygen Molecules.

    PubMed

    Wang, Hui; Shi, Chuntai; Hu, Jun; Han, Sungho; Yu, Clare C; Wu, R Q

    2015-08-14

    A major obstacle to using superconducting quantum interference devices (SQUIDs) as qubits is flux noise. We propose that the heretofore mysterious spins producing flux noise could be O_{2} molecules adsorbed on the surface. Using density functional theory calculations, we find that an O_{2} molecule adsorbed on an α-alumina surface has a magnetic moment of ~1.8 μ_{B}. The spin is oriented perpendicular to the axis of the O-O bond, the barrier to spin rotations is about 10 mK. Monte Carlo simulations of ferromagnetically coupled, anisotropic XY spins on a square lattice find 1/f magnetization noise, consistent with flux noise in Al SQUIDs. PMID:26317742

  5. nanoSQUID operation using kinetic rather than magnetic induction

    NASA Astrophysics Data System (ADS)

    McCaughan, Adam N.; Zhao, Qingyuan; Berggren, Karl K.

    2016-06-01

    We report on a method of nanoSQUID modulation which uses kinetic inductance rather than magnetic inductance to manip-ulate the internal fluxoid state. We produced modulation using injected current rather than an applied magnetic field. Using this injected current, we were able to observe the triangle-wave shaped modulation of the device critical current which was periodic according to the London fluxoid quantization condition. The measurement results also confirmed that the fluxoid state inside a superconducting loop can be manipulated using primarily kinetic inductance. By using primarily kinetic inductance rather than magnetic inductance, the size of the coupling inductor was reduced by a factor of 10. As a result, this approach may provide a means to reduce the size of SQUID-based superconducting electronics. Additionally, this method provides a convenient way to perform kinetic inductance characterizations of superconducting thin films.

  6. SQUID-detected NMR in Earth's magnetic field

    NASA Astrophysics Data System (ADS)

    Qiu, L. Q.; Zhang, Y.; Krause, H.-J.; Braginski, A. I.

    2008-02-01

    Under the highly homogeneous Earth's magnetic field (EMF), nuclear magnetic resonance experiments were performed utilizing a nitrogen-cooled superconducting quantum interference device (SQUID). The Larmor frequency fL of protons is around 2060 Hz in our environment. The sensitivity of our SQUID magnetometer in EMF reached about 70 fT/√Hz near this fL. Free induction decay curves were obtained with a high signal-to-noise ratio. The amplitude of the NMR signal agreed with the theoretical value. The 1H spectra of some samples, for instance, tap water, benzene, ethanol and toluene were studied. The hetero-nuclear J coupling spectrum of 2,2,2-trifluoroethanol was clearly obtained. The influence of EMF fluctuations on the linewidth is also observed.

  7. Scanning SQUID microscopy in a cryogen-free refrigerator

    NASA Astrophysics Data System (ADS)

    Schaefer, Brian T.; Low, David; Prawiroatmodjo, Guenevere E. D. K.; Nangoi, J. Kevin; Kim, Jihoon; Nowack, Katja C.

    With helium prices rising and supply becoming increasingly uncertain, it has become attractive to use dry cryostats with cryocoolers rather than liquid helium to reach low temperatures. However, a cryocooler introduces vibrations at the sample stage, making scanning probe experiments more challenging. Here, we report our progress on a superconducting quantum interference device (SQUID) microscope implemented for the first time in a compact, cryogen-free 5 K system. Our microscope is designed to reach submicron spatial resolution and a flux sensitivity of approximately 1 μΦ0 /√{ Hz} , where Φ0 is the magnetic flux quantum. To enable height feedback while approaching and scanning samples, we mount the SQUID on a quartz tuning fork. Our system promises to meet the capabilities of similar systems implemented in helium cryostats.

  8. nSQUID arrays as conveyers of quantum information

    SciTech Connect

    Deng, Qiang; Averin, D. V.

    2014-12-15

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

  9. A three-axis SQUID-based absolute vector magnetometer

    SciTech Connect

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

    2015-10-15

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth’s magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz{sup 1/2}. The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  10. Helium-neon laser therapy in the treatment of hydroxyapatite orbital implant exposure: A superior option

    PubMed Central

    XU, QI-HUA; ZHAO, CHEN; ZHU, JIAN-GANG; CHEN, MEI-JUAN; LIU, QING-HUAI

    2015-01-01

    The aim of the present study was to evaluate the efficacy of helium-neon laser therapy in the treatment of hydroxyapatite orbital implant exposure and compare the results with those of a combined drugs and surgery regimen. A total of 70 patients with hydroxyapatite orbital implant exposure in 70 eyes were randomly divided into two groups: Helium-neon laser therapy (group A) and drugs plus surgery (group B). Each group contained 35 patients. The healing rates and times of the conjunctival wound were recorded and compared following helium-neon laser treatment or the drugs plus surgery regimen. Changes in the hydroxyapatite orbital implant prior to and following helium-neon laser irradiation were analyzed. A similar animal study was conducted using 24 New Zealand white rabbits, which received orbital implants and were then received drug treatment or helium-neon therapy. In the human experiment, the rates for conjunctival wound healing were 97.14% in group A and 74.29% in group B, with a significant difference between the groups (χ2=5.71, P<0.05). Patients with mild exposure were healed after 7.22±2.11 days of helium-neon laser therapy and 14.33±3.20 days of drugs plus surgery. A statistically significant difference was found between the groups (t=8.97, P<0.05). Patients with moderate to severe exposure were healed after 18.19±2.12 days of helium-neon laser therapy and 31.25±4.21 days of drugs plus surgery. The difference between the groups was statistically significant (t=7.91, P<0.05). Enhanced magnetic resonance imaging showed that the helium-neon laser therapy significantly promoted vascularization of the hydroxyapatite orbital implant. These results, combined with pathological findings in animals, which showed that a helium-neon laser promoted vascularization and had anti-inflammatory effects, suggest that helium-neon laser irradiation is an effective method for treating hydroxyapatite orbital implant exposure, thereby avoiding secondary surgery. PMID

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

    DOEpatents

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

    1984-01-01

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

  12. Squid nerve sphingomyelin containing an unusual sphingoid base.

    PubMed

    Ohashi, Y; Tanaka, T; Akashi, S; Morimoto, S; Kishimoto, Y; Nagai, Y

    2000-07-01

    A new methodology has been developed to determine sphingolipid structures by positive-ion fast atom bombardment tandem mass spectrometry (FAB-MS/MS). The method was verified by application to a structurally known glycosphingolipid, and then used in the structural study of an unusual sphingomyelin isolated from squid (Loligo pealei) nerve. Our previous study of this squid sphingomyelin indicated that the major base had a branched C(19) alkyl chain with three double bonds, two of which were conjugated. The positions of the branching as well as the double bonds of this base were unambiguously determined by directly comparing the product ion spectra of the long-chain base ion (LCB(+)) of two ceramides, one derived from squid nerve sphingomyelin and another, glucosylceramide, obtained from starfish spermatozoa. The latter served as the standard because the structure had already been determined by nuclear magnetic resonance (NMR). The precursor ion here was LCB(+), that is, [CH(2) - C(NH(2)) = CHR](+), rather than [M + H](+), where R represents the backbone hydrocarbon chain counting from C-4. The results clearly showed that the squid nerve base is identical to the base derived from starfish (Asterias amurensis), that is, 2-amino-9-methyl-4,8,10-octadecatriene-1,3-diol. This is the first report in which the detailed structure of a branched polyunsaturated sphingoid base was studied by tandem mass spectrometry without derivatization or the aid of NMR. The occurrence of such an unusual sphingoid base in various phyla and tissues suggests the conjugated polyunsaturated branched sphingoid base plays a significant role in animals. PMID:10884294

  13. Detecting damage in steel with scanning SQUID microscopy

    SciTech Connect

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

    2001-09-04

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

  14. Elimination of flux-transformer crosstalk in multichannel SQUID magnetometers

    NASA Astrophysics Data System (ADS)

    ter Brake, H. J. M.; Fleuren, F. H.; Ulfrnan, J. A.; Flokstra, J.

    Multichannel SQUID magnetometers are being developed for signal-field mapping in biomagnetic experiments. A problem that becomes more serious as the number of channels is increased is the crosstalk caused by the mutual inductances between the individual sensing coils. A simple and effective method for eliminating this crosstalk is presented in this Paper. The method is based on a rearrangement of the feedback loops which causes the flux-transformer circuits to become currentless. The feasibility of the method is verified experimentally.

  15. Cosmological flux noise and measured noise power spectra in SQUIDs

    PubMed Central

    Beck, Christian

    2016-01-01

    The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe. PMID:27320418

  16. Hierarchical, Self-Similar Structure in Native Squid Pen

    NASA Astrophysics Data System (ADS)

    Yang, Fei-Chi; Peters, Robert; Dies, Hannah; Rheinstadter, Maikel

    2014-03-01

    Proteins, chitin and keratin form the elementary building blocks of many biomaterials. How these molecules assemble into larger, macroscopic structures with very different properties is the fundamental question we are trying to answer. Squid pen is a transparent backbone inside the squid, which supports the mantle of the squid. The pens show a hierarchical, self-similar structure under the microscope and the AFM with fibers from 500 μm to 0.2 μm in diameter. The chitin molecules form nano-crystallites of monoclinic lattice symmetry surrounded by a protein layer, resulting in β-chitin nano-fibrils. Signals corresponding to the α-coil protein phase and β-chitin were observed in X-ray experiments in-situ. The molecular structure is highly anisotropic with 90% of the α-coils and β-chitin crystallites oriented along the fiber-axis indicating a strong correlation between the structures on millimeters down to the molecular scale. This research was funded by NSERC, NRC, CFI, and the Ontario Ministry of Economic Development and Innovation.

  17. Low-frequency nuclear quadrupole resonance with a dc SQUID

    SciTech Connect

    Chang, J.W.

    1991-07-01

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

  18. Transparency and coherence in rf SQUID metamaterials (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Anlage, Steven M.

    2015-09-01

    We have developed active metamaterials based on macroscopic quantum effects capable of quickly tuning their electrical and magnetic responses over a wide frequency range. These metamaterials are based on superconducting elements to form low insertion loss, physically and electrically small, highly tunable structures for the next generation rf electronics. The meta-atoms are rf superconducting quantum interference devices (SQUIDs) that incorporate the Josephson effect. RF SQUIDs have an inductance which includes a contribution from the Josephson inductance of the junction. This inductance is strongly tunable with dc and rf magnetic fields and currents. The rf SQUID metamaterial is a richly nonlinear effective medium introducing qualitatively new macroscopic quantum phenomena into the metamaterials community, namely magnetic flux quantization and the Josephson effect. The coherence of the metamaterials is strongly sensitive to the environment and measurement conditions. The metamaterials also display a unique form of transparency whose development can be manipulated through multiple parametric dependences. Further features such as breathers, superradiance, and self-induced transparency, along with entry into the fully quantum limit, will yield qualitatively new metamaterial phenomena. This work is supported by the NSF-GOALI and OISE Programs through Grant No. ECCS-1158644 and the Center for Nanophysics and Advanced Materials (CNAM).

  19. 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.

  20. Fabrication and characterization of shunted μ-SQUID

    SciTech Connect

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

    2014-04-24

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

  1. Cosmological flux noise and measured noise power spectra in SQUIDs

    NASA Astrophysics Data System (ADS)

    Beck, Christian

    2016-06-01

    The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe.

  2. Cosmological flux noise and measured noise power spectra in SQUIDs.

    PubMed

    Beck, Christian

    2016-01-01

    The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe. PMID:27320418

  3. 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

  4. 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.

  5. Fabrication and characterization of shunted μ-SQUID

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    In order to eliminate hysteresis, we have fabricated and characterized niobium based shunted micron size superconducting quantum interference devices (μ-SQUIDs). We find a wide temperature range where these μ-SQUIDs are non-hysteretic in nature and show a very good Ic vs. B oscillations in hysteretic regime and V vs. B oscillations in non-hysteretic regime. Here we report the characteristics of a shunted- μ-SQUID (Wf38LS72D5). In this device we have achieved a large voltage modulation, in non-hysteretic regime, at various temperatures including such as 1.1 mV at 6.62 K with a transfer function VΦ = 7.2mV/Φ0. The figures within the original article PDF file, as supplied to AIP Publishing, were affected by a PDF-processing error. Consequently, the article re-flowed and pagination increased from 3 to 4 pages. This article was updated on 14 May 2014 to correct the PDF-processing error, with the scientific content remaining unchanged. Readers are advised that the replacement article PDF file contains an additional blank page to preserve the original pagination.

  6. Magnetic flux in a mesoscopic SQUID controlled by nonclassical electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Dajka, Jerzy; Łuczka, Jerzy

    2009-11-01

    We analyze SQUID coupled to a nonclassical electromagnetic field (NEM) and show that properties of the SQUID can be manipulated by a choice of a state of NEM. In particular, energy or fluctuations of magnetic flux threading the loop of the SQUID can be resolved into separate lines for each photon number state of one-mode NEM. The impact of two-mode NEM prepared in entangled Bell states is discussed. The findings suggest an experimental method of detection of photon states: the SQUID response is dependent on the number of photons in one-mode NEM and on the Bell states of a two-mode NEM.

  7. Isolation and characteristics of trypsin inhibitor from the hepatopancreas of a squid (Todarodes pacificus).

    PubMed

    Kishimura, H; Saeki, H; Hayashi, K

    2001-08-01

    Trypsin inhibitor was purified from the hepatopancreas of squid (Todarodes pacificus). The final inhibitor preparation was nearly homogeneous by SDS-PAGE with an estimated molecular weight of approximately 6300. The squid trypsin inhibitor was acid- and heat-stable, and active against trypsins from the pyloric ceca of starfish (Asterias amurensis) and saury (Cololabis saira) and porcine pancreatic trypsin. Amino acid composition of the squid trypsin inhibitor was compared with other invertebrate trypsin inhibitors. The squid trypsin inhibitor inhibited the autolysis of walleye pollock (Theragra chalcogramma) myofibrillar proteins. PMID:11470450

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  9. Positron scattering and ionization of neon atoms — theoretical investigations

    NASA Astrophysics Data System (ADS)

    Harshit, N. Kothari; N. Joshipura, K.

    2010-10-01

    Although positron scattering with inert gas atoms has been studied in theory as well as in experiment, there are discrepancies. The present work reports all the major total cross sections of e+—neon scattering at incident energies above ionization threshold, originating from a complex potential formalism. Elastic and cumulative inelastic scatterings are treated in the complex spherical e+—atom potential. Our total inelastic cross section includes positronium formation together with ionization and excitation channels in Ne. Because of the Ps formation channel it is difficult to separate out ionization cross sections from the total inelastic cross sections. An approximate method similar to electron—atom scattering has been applied to bifurcate ionization and cumulative excitation cross sections at energies from threshold to 2000 eV. Comparisons of present results with available data are made. An important outcome of this work is the relative contribution of different scattering processes, which we have shown by a bar-chart at the ionization peak.

  10. Quantum scattering of neon from a nanotextured surface.

    PubMed

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

    2009-06-01

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

  11. 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.

  12. Interstellar oxygen, nitrogen and neon in the heliosphere

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  13. Strange particle production in neutrino-neon charged current interactions

    SciTech Connect

    Plano, R.; Baker, N.J.; Connolly, P.L.; Kahn, S.A.; Murtagh, M.J.; Palmer, R.B.; Samios, N.P.; Tanaka, M.; Baltay, C.; Bregman, M.

    1986-01-01

    Neutral strange particle production in charged-current muon-neutrino interactions have been studied in the Fermilab 15-foot neon bubble chamber. Associated production is expected to be the major source of strange particles in charged-current neutrino interactions. sigma-neutral and xi-minus production by neutrinos was observed. The dependence on various leptonic and hadronic variables is investigated. A fit to single and associated production of s, s/anti-s, and c quarks is described based on the number of single and double strange particle production events. Inclusive neutral strange particle decays (V/sup 0/) production rates as a fraction of all charged-current events are measured and are tabulated. The lambda/K ratio is found to be 0.39 +- 0.04 and the fraction of lambda coming from sigma-neutral is (16 +- 5)%. The single- and double V/sup 0/ production was used to determine the associated s anti-s production rate and single s-quark production rate. 13 refs., 7 figs., 3 tabs. (LEW)

  14. Neon turbo-Brayton cycle refrigerator for HTS power machines

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  15. Isotopes of cosmic ray elements from neon to nickel

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    Results obtained from a balloon exposure of a cosmic ray detector flown in 1977 are reported. The charge resolution ranged from 0.19 to 0.21 charge units between neon and nickel and the mass resolution for nuclei stopped in the emulsions ranged from 0.40 to 0.70 amu for A between 20 and 60 amu. This was enough to correctly identify almost all nuclei, but not to uniquely resolve neighboring mass peaks. Both Ne and Mg show evidence for neutron enrichment relative to the solar system abundance. Si and S are consistent with solar abundances, while Ar has no significant source abundances. P, Cl and K have essentially no primary component and the isotopic distribution observed is quite consistent with that expected from propagation. An excess of Ca-44 at the source is shown, indicating high metallicity in the source. The abundance of Fe-58 is nine percent or less, and Ni shows a one-to-one ratio for Ni-58 to 60, implying intermediate metallicity.

  16. The isotopes of neon in the galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Simpson, J. A.; Wefel, J. P.

    1979-01-01

    The paper examines the results obtained by the University of Chicago instrument on board the IMP 7 satellite used to measure the abundances of Ne-20 and Ne-22 in the galactic cosmic rays during 1973-1977, over the general energy range of 60-230 MeV per nucleon. It is reported that the instrument shows a mass resolution of 0.7 amu(sigma) which was confirmed by calibrating a backup instrument at the LBL Bevalac with separated beams of neon isotopes. Through the use of standard solar modulation and cosmic-ray propagation models, the cosmic-ray source ratio inferred is Ne-22/Ne-20 = 0.38 = or -0.07 which is significantly greater than the present solar system ratio. It is concluded that propagation effects or cross-section uncertainties cannot account for such a large abundance of Ne-22, and thus this measurement provides evidence that the cosmic rays come from a source region where the Ne-22 abundance is substantially greater than in solar system material.

  17. Relativistic Effects in the Photoionization-Excitation of Neon

    NASA Astrophysics Data System (ADS)

    Gorczyca, T. W.; Felfli, Z.

    1998-05-01

    In a purely non-relativistic theoretical treatment of the neon 2p^43s(^2P) satellite, the angular distribution parameter and the ratio of populations of the ^2P_3/2 and ^2P_1/2 ionic fine structure levels are both independent of photon energy. Recent synchrotron measurements(A. A. Wills, N. Berrah, T. W. Gorczyca, B. Langer, Z. Felfli, M. Alsheri, O. Nayandin, and J. D. Bozek, unpublished) have observed marked deviation from this predicted behavior, however, indicating that spin-orbit effects are important. In order to study spin-orbit effects in this region of complex doubly-excited resonances, we have performed R-matrix calculations to determine MQDT scattering and dipole matrices. Important computational aspects are 1) an extensive configuration interaction (CI) for target and scattering wavefunctions, 2) a recoupling transformation from LS-coupled to JK-coupled matrices, 3) a second transformation using term coupling coefficients of the ionic targets, and 4) the MQDT reduction to physical scattering matrices using experimental fine structure target energies. The resultant differential cross sections, resolved into photoelectron angle and final ionic fine structure level, show many interesting deviations from the LS-predicted behavior, and are compared to the recent experimental results.^1

  18. 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.

  19. SQUID detected NMR and NQR. Superconducting Quantum Interference Device.

    PubMed

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

    1998-03-01

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

  20. Hydrodynamic fin function of brief squid, Lolliguncula brevis.

    PubMed

    Stewart, William J; Bartol, Ian K; Krueger, Paul S

    2010-06-15

    Although the pulsed jet is often considered the foundation of a squid's locomotive system, the lateral fins also probably play an important role in swimming, potentially providing thrust, lift and dynamic stability as needed. Fin morphology and movement vary greatly among squid species, but the locomotive role of the fins is not well understood. To begin to elucidate the locomotive role of the fins in squids, fin hydrodynamics were studied in the brief squid Lolliguncula brevis, a species that exhibits a wide range of fin movements depending on swimming speed. Individual squid were trained to swim in both the arms-first and tail-first orientations against currents in a water tunnel seeded with light-reflective particles. Particle-laden water around the fins was illuminated with lasers and videotaped so that flow dynamics around the fins could be analyzed using digital particle image velocimetry (DPIV). Time-averaged forces generated by the fin were quantified from vorticity fields of the fin wake. During the low swimming speeds considered in this study [<2.5 dorsal mantle lengths (DML) per second], L. brevis exhibited four unique fin wake patterns, each with distinctive vortical structures: (1) fin mode I, in which one vortex is shed with each downstroke, generally occurring at low speeds; (2) fin mode II, an undulatory mode in which a continuous linked chain of vortices is produced; (3) fin mode III, in which one vortex is shed with each downstroke and upstroke, and; (4) fin mode IV, in which a discontinuous chain of linked double vortex structures is produced. All modes were detected during tail-first swimming but only fin modes II and III were observed during arms-first swimming. The fins produced horizontal and vertical forces of varying degrees depending on stroke phase, swimming speed, and swimming orientation. During tail-first swimming, the fins functioned primarily as stabilizers at low speeds before shifting to propulsors as speed increased, all while

  1. Autonomous Flying Controls Testbed

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.

    2005-01-01

    The Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis,Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights.

  2. Complexity and Fly Swarms

    NASA Astrophysics Data System (ADS)

    Cates, Grant; Murray, Joelle

    Complexity is the study of phenomena that emerge from a collection of interacting objects and arises in many systems throughout physics, biology, finance, economics and more. Certain kinds of complex systems can be described by self-organized criticality (SOC). An SOC system is one that is internally driven towards some critical state. Recent experimental work suggests scaling behavior of fly swarms-one of the hallmarks of an SOC system. Our goal is to look for SOC behavior in computational models of fly swarms.

  3. Development of a Domain Map for Nodes of the National Ecological Observatory Network (NEON)

    NASA Astrophysics Data System (ADS)

    Hargrove, W. W.; Hoffman, F. M.; Hayden, B. P.; Urban, D. L.; MacMahon, J. A.; Franklin, J. F.

    2005-12-01

    The National Ecological Observatory Network (NEON) will be the first ecological measurement system designed both to answer regional- to national-scale scientific questions and to have the interdisciplinary participation necessary to achieve credible ecological forecasting and prediction. Capabilities provided by this infrastructural investment will transform the science of ecology by enabling the integration of research and education from natural and human systems. A National Network Design Committee (NNDC) of 15 individuals has been tasked with providing a baseline design for NEON, including the continental-scale deployment of NEON network resources. A system of identical nodes, each representing environments within a mother geographic "domain" was envisioned. Each node would itself consist of sub-node components, and all nodes would be focused in unison on a few transformational ecological questions of national relevance. The NNDC adopted a strategy of pre-stratification to help determine an optimum number of nodes and to maximize node representativeness. To better sample a phenomenon as diverse as the ecological environments of the United States, those environments were first divided into a set of more homogeneous "strata." Samples could then be arrayed within each stratum, ensuring that NEON nodes are representative of the entire range of environments within the United States. Ecoregions have classically been used by ecologists for such national stratification. Ecoregions have historically been drawn using human expertise in a qualitative, weight-of-evidence approach. To construct NEON domains, a more transparent and repeatable process was needed. Multivariate clustering based on national maps of 9 ecologically relevant climatic "state" variables was used to repeatably define 25 national climatic zones. These 25 climate zones were combined with dynamic air mass seasonality data to create 20 NEON domains, each having similar climate. Such domains are defensible

  4. A strategy to sample nutrient dynamics across the terrestrial-aquatic interface at NEON sites

    NASA Astrophysics Data System (ADS)

    Hinckley, E. S.; Goodman, K. J.; Roehm, C. L.; Meier, C. L.; Luo, H.; Ayres, E.; Parnell, J.; Krause, K.; Fox, A. M.; SanClements, M.; Fitzgerald, M.; Barnett, D.; Loescher, H. W.; Schimel, D.

    2012-12-01

    The construction of the National Ecological Observatory Network (NEON) across the U.S. creates the opportunity for researchers to investigate biogeochemical transformations and transfers across ecosystems at local-to-continental scales. Here, we examine a subset of NEON sites where atmospheric, terrestrial, and aquatic observations will be collected for 30 years. These sites are located across a range of hydrological regimes, including flashy rain-driven, shallow sub-surface (perched, pipe-flow, etc), and deep groundwater, which likely affect the chemical forms and quantities of reactive elements that are retained and/or mobilized across landscapes. We present a novel spatial and temporal sampling design that enables researchers to evaluate long-term trends in carbon, nitrogen, and phosphorus biogeochemical cycles under these different hydrological regimes. This design focuses on inputs to the terrestrial system (atmospheric deposition, bulk precipitation), transfers (soil-water and groundwater sources/chemistry), and outputs (surface water, and evapotranspiration). We discuss both data that will be collected as part of the current NEON design, as well as how the research community can supplement the NEON design through collaborative efforts, such as providing additional datasets, including soil biogeochemical processes and trace gas emissions, and developing collaborative research networks. Current engagement with the research community working at the terrestrial-aquatic interface is critical to NEON's success as we begin construction, to ensure that high-quality, standardized and useful data are not only made available, but inspire further, cutting-edge research.

  5. National Ecological Observatory Network's (NEON) future role in US carbon cycling and budgets

    NASA Astrophysics Data System (ADS)

    Loescher, H. W.

    2015-12-01

    The US National Ecological Observatory Network (NEON) is a National Science Foundation investment designed to observe the impacts of large-scale environment changes on the nation's ecosystems for 30 years with rigorous consistency. NEON does this through the construction (and operations) of new physical infrastructure and data infrastructure distributed across the North American Continent. This includes 47 terrestrial and 32 aquatic sites. Key to its design is its ability to provide ecosystem-scale carbon measurements of carbon stores, fluxes, processes—and the means to scale them from the local-to regional scales via remote sensed aircraft. NEON design NEON will be collecting these carbon data as a facility and providing openly providing them. NEON will not preform any high-level synthesis, rather the carbon data is an open resource for research, private and public communities, alike. Overall, these data are also harmonized with other international carbon-based infrastructures to facilitate cross-continental understanding and global carbon syntheses. Products, engagement and harmonization of data to facilitate syntheses will be discussed.

  6. Economic Impact of Stable Flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dynamic model was created to estimate the economic impact of stable flies on livestock production. Based upon a nationwide average of 10 stable flies per animal for 3 months per year, the model estimates the impact of stable flies to be $543 million to the dairy industry, $1.34 billion to pasture ...

  7. Flying High with Spring.

    ERIC Educational Resources Information Center

    Harrington, Carolyn Lang

    2000-01-01

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

  8. 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…

  9. Learning to Fly.

    ERIC Educational Resources Information Center

    Weil, Patricia E.

    1983-01-01

    Presents information on where to learn to fly, which aircraft is best for this purpose, and approximate costs. Includes additional information on certificates, licenses, and ratings, and a description of the two phases of the General Aviation Manufacturers Association flight training program. (JN)

  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-ash utilization

    SciTech Connect

    Lockerby, R.W.

    1984-01-01

    The over 200 references in this bibliography cover some of the uses found for fly-ash, which range from the manufacture of bricks and as a new type of concrete to the recovery of aluminum and other valuable ores from the ash. The entries are grouped under seven headings: General, Agriculture, Brickmaking, Cement/Concrete, Land Reclamation, Resource Recovery, and Other.

  12. Wisdom from the fly.

    PubMed

    Rieder, Leila E; Larschan, Erica N

    2014-11-01

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

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

    SciTech Connect

    Golovashkin, A. I.; Zherikhina, L. N. Tskhovrebov, A. M.; Izmailov, G. N.; Ozolin, V. V.

    2010-08-15

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

  14. 77 FR 40527 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... percent of the quota (8,888 mt) (77 FR 16472, March 21, 2012). Due to an underharvest of quota in... Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the 2012 Trimester 2 Directed Longfin Squid Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic...

  15. 76 FR 51272 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-18

    ... Loligo was set at 3,384 mt (76 FR 8306, February 14, 2011). Due to an under harvest of the Trimester 1... Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the 2011 Trimester 2 Directed Loligo Squid Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic...

  16. 75 FR 1024 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-08

    ..., 2003 (68 FR 27516), NMFS published, at the request of the Council, an ANPR indicating that the Council... United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Control Date for Loligo and Illex Squid AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric...

  17. 77 FR 58507 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ...-9135. SUPPLEMENTARY INFORMATION: Background Amendment 11 to the MSB FMP (76 FR 68642, November 7, 2011... United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Framework Adjustment 5 AGENCY... Adjustment 5 to the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan (MSB FMP), which...

  18. 76 FR 74724 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... November 7, 2011 (76 FR 68642). Details regarding the measures in Amendment 11 are in the final rule and... United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Amendment 11 AGENCY: National Marine... implementing Amendment 11 to the Atlantic Mackerel, Squid, and Butterfish (MSB) Fishery Management Plan...

  19. 75 FR 37739 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ... Butterfish Fisheries in the Federal Register on February 3, 2010 (75 FR 5537). The final rule modified... United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Adjustment to the Loligo Trimester 2... Fishing Year (FY) Trimester 2 and 3 Loligo squid quotas. This action complies with the 2010...

  20. 75 FR 51683 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... FR 5537, February 3, 2010). Section 648.22 requires NMFS to close the directed butterfish fishery in... United States; Atlantic Mackerel, Squid, and Butterfish Fisheries; Closure of the Directed Butterfish..., Squid, and Butterfish Fishery Management Plan (FMP). The procedures for setting the annual...

  1. 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.

  2. SQUIDS and their applications in the measurement of weak magnetic fields

    NASA Astrophysics Data System (ADS)

    Swithenby, S. J.

    1980-08-01

    The theory and operation of superconducting quantum interference devices (SQUID) are outlined. Possible applcations of SQUID systems in the measurement of weak magnetic fields associated with the human body are discussed. A forecast is made of the progress to be expected in the next few years.

  3. A YBCO RF-squid variable temperature susceptometer and its applications

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  4. Photochemistry of the ozone-water complex in cryogenic neon, argon, and krypton matrixes.

    PubMed

    Tsuge, Masashi; Tsuji, Kazuhide; Kawai, Akio; Shibuya, Kazuhiko

    2013-12-12

    The photochemistry of ozone-water complexes and the wavelength dependence of the reactions were studied by matrix isolation FTIR spectrometry in neon, argon, and krypton matrixes. Hydrogen peroxide was formed upon the irradiation of UV light below 355 nm. Quantitative analyses of the reactant and product were performed to evaluate the matrix cage effect of the photoreaction. In argon and krypton matrixes, a bimolecular O((1)D) + H2O → H2O2 reaction was found to occur to form hydrogen peroxide, where the O((1)D) atom generated by the photolysis of ozone diffused in the cryogenic solids to encounter water. In a neon matrix, hydrogen peroxide was generated through intracage photoreaction of the ozone-water complex, indicating that a neon matrix medium is most appropriate to study the photochemistry of the ozone-water complex. PMID:24252115

  5. Essential features of optical processes in neon-buffered submicron-thin Rb vapor cell.

    PubMed

    Hakhumyan, Grant; Sargsyan, Armen; Leroy, Claude; Pashayan-Leroy, Yevgenya; Papoyan, Aram; Sarkisyan, David

    2010-07-01

    A new submicron thin cell (STC) filled with Rb and neon gas is developed and comparison of resonant absorption with STC containing pure Rb is provided. The effect of collapse and revival of Dicke-type narrowing is still observable for the thickness L = lambda /2 and L = lambda , where lambda is a resonant laser wavelength 794 nm (D(1) line). For an ordinary Rb cm-size cell with addition of buffer gas, the velocity selective optical pumping/saturation (VSOP) resonances in saturated absorption spectra are fully suppressed if neon pressure > 0.5 Torr. A spectacular difference is that for L = lambda , VSOP resonances are still observable even when neon pressure is > or = 6 Torr. Narrow fluorescence spectra at L = lambda /2 allow one to realize online buffer gas pressure monitoring. A good agreement with theoretical model is observed. PMID:20639943

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

    PubMed

    Packwood, Daniel M; Phillips, Leon F

    2011-01-14

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

  7. Demonstrating a directional detector based on neon for characterizing high energy neutrons

    NASA Astrophysics Data System (ADS)

    Hexley, Allie

    2016-03-01

    MITPC is a gas-based time projection chamber used for detecting fast, MeV-scale neutrons. The standard version of the detector relies on a mixture of 600 torr gas composed of 87.5% helium-4 and 12.5% tetrafluoromethane for precisely measuring the energy and direction of neutron-induced nuclear recoils. I describe studies performed with a prototype detector investigating the use of neon, as a replacement for helium-4, in the gas mixture. My discussion focuses on the advantages of neon as the fast neutron target for high energy neutron events (100 MeV) and a demonstration that the mixture will be effective for this event class. I show that the achievable gain and transverse diffusion of drifting electrons in the neon mixture are acceptable and that the detector uptime lost due to voltage breakdowns in the amplification plane is negligible, compared to 20% with the helium-4 mixture.

  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

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

    NASA Astrophysics Data System (ADS)

    He, D. F.; Itozaki, H.

    2006-10-01

    Using AD797 low noise op amps and 2SA1048 low noise transistors, we have developed a composite preamplifier for use in dc SQUID readout electronics. This preamplifier has a small dc drift and super low noise at high frequencies. The equivalent input voltage noise of the preamplifier is about 0.35 nV/√Hz from 100 kHz to 10 MHz. Using this preamplifier, we developed dc SQUID readout electronics having low noise and high bandwidth. Used with a 3 mm2 high-Tc dc SQUID, the white flux noise was about 18 μΦ0/√Hz above 100 kHz and the FLL bandwidth was about 2 MHz. This readout electronics can be used for the applications of SQUID-based NDE and SQUID-based NQR.

  10. The fabrication and characterization of nano-SQUIDs based on Nb thin films

    NASA Astrophysics Data System (ADS)

    Liu, Xixi; Liu, Xiaoyu; Wang, Hao; Chen, Lei; Wang, Zhen

    2015-08-01

    SQUIDs with nano-junctions (or nano-SQUIDs) are able to be miniaturized into nanoscale to measure a single Bohr magneton. Here, we reported the development of a fabrication process for Nb (niobium) nano-SQUIDs using the thin film deposition and the electron-beam lithography technology. The developed process started from a high-quality superconducting thin film so that it is compatible with a variety of film growing techniques. The as-fabricated nano-SQUIDs exhibited functional flux modulation depth up to 10.3% at 4.6 K, in agreement with the numerical simulation based on the Ginzburg-Landau equation. By further comparing the results from both experiments and simulations, we found that a small critical current below ∼50 μA played a leading role in order to obtain a decent flux-modulation depth for Nb nano-SQUIDs.

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

    NASA Technical Reports Server (NTRS)

    Lu, D. F.

    1995-01-01

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

  12. Metallic Magnetic Calorimeters with On-Chip dc-SQUID Readout

    NASA Astrophysics Data System (ADS)

    Kempf, S.; Ferring, A.; Fleischmann, A.; Wegner, M.; Enss, C.

    2016-07-01

    Metallic magnetic calorimeters (MMCs) are low-temperature particle detectors that are typically read out by using superconducting quantum interference devices (SQUIDs). But since MMCs are sensitive to the input circuitry and the noise performance of the SQUID, the energy resolution of MMCs have not yet reached their fundamental limit. A possible solution to overcome present limits is to maximize the flux coupling by minimizing parasitic inductance in the input circuit. To show the suitability of this approach, we realized a 64 pixel MMC detector array with integrated dc-SQUID readout, i.e., detector and SQUID are on the same chip. We observed an influence of the power dissipation of the SQUID on the detector temperature. We achieved a baseline energy resolution of Δ E_mathrm {FWHM} = 25 mathrm {eV} and Δ E_mathrm {FWHM} = 30 mathrm {eV} for X-rays with energies up to 6 mathrm {keV}.

  13. Metallic Magnetic Calorimeters with On-Chip dc-SQUID Readout

    NASA Astrophysics Data System (ADS)

    Kempf, S.; Ferring, A.; Fleischmann, A.; Wegner, M.; Enss, C.

    2016-07-01

    Metallic magnetic calorimeters (MMCs) are low-temperature particle detectors that are typically read out by using superconducting quantum interference devices (SQUIDs). But since MMCs are sensitive to the input circuitry and the noise performance of the SQUID, the energy resolution of MMCs have not yet reached their fundamental limit. A possible solution to overcome present limits is to maximize the flux coupling by minimizing parasitic inductance in the input circuit. To show the suitability of this approach, we realized a 64 pixel MMC detector array with integrated dc-SQUID readout, i.e., detector and SQUID are on the same chip. We observed an influence of the power dissipation of the SQUID on the detector temperature. We achieved a baseline energy resolution of Δ E_{FWHM} = 25 {eV} and Δ E_{FWHM} = 30 {eV} for X-rays with energies up to 6 {keV}.

  14. Big Data and Ecological Forecasting: Integrating NEON Observational and Sensor Data from Reach to Continent

    NASA Astrophysics Data System (ADS)

    Vance, J. M.; Goodman, K. J.; Lunch, C. K.; Fitzgerald, M.

    2015-12-01

    The ability to forecast the response of varied ecosystems to changes in climate and land use will be crucial for the management of resources and ecosystem services. Ecological forecasting presents many significant challenges within each of the aspects of data capture, assimilation, and modeling. High space-time resolution sampling is required to address the challenges of scaling from the site level to the continent. Determining the uncertainty of data used for model input and parameterization is critical for constraining the model for accurate representation. The National Ecological Observatory Network (NEON) is poised to greatly expand the scale and availability of biogeochemical and aquatic ecological data. NEON is a continental-scale facility designed to collect and disseminate data that addresses the impacts of climate change, land-use, and invasive species on ecosystem structure and function. Using a combination of standardized observational sampling and sensor measurements, NEON will provide a rich source of biogeochemical and biophysical data from 34 aquatic and 47 terrestrial sites spatially distributed across the US, including Alaska, Hawaii and Puerto Rico for 30 years. Sites were selected to be representative of major ecosystems and maximize scalability. In addition to standardizing measurements, NEON is determining the quantitative uncertainty of each data product making them well suited to constrain models. NEON aquatic data will not only serve to baseline aquatic ecology in major ecosystems but also presents opportunities to bolster Hydrologic Models as well as incorporate aquatic biogeochemical cycling into Land Surface Models. Here we present examples of published and provisional data currently available from deployed aquatic sites, as well as an overview of the full scope and release schedule of the open source ecological data to be published on the NEON web portal. Several use cases, such as whole stream metabolism, groundwater exchange, high

  15. NEON: Developing a Platform for Regional to Continental Scale Biological Inquiry

    NASA Astrophysics Data System (ADS)

    Goldman, J.

    2004-05-01

    Climate variation, introductions of alien species, and patterns of land use are some of the important interacting drivers of biological change that are affecting our nation's ecosystems. Many of these drivers operate over large spatial and temporal scales, and our understanding of how these phenomena interact to drive biological change is limited by our inability to link traditionally local and short-term ecological approaches to larger and longer scales. Similarly, our ability to forecast such changes and respond to their consequences is constrained. The National Ecological Observatory Network (NEON) is a proposed shared-use research and education platform intended to improve our capacity to understand and predict biological phenomena operating from regional to continental scales. NEON is envisioned as a system of field and laboratory-based facilities distributed across the United States, which will provide the physical infrastructure and human capabilities necessary to coordinate and integrate research and education campaigns on the following types of issues: (1) biodiversity, species composition, and ecosystem functioning; (2) ecological aspects of biogeochemical cycles; (3) ecological implications of climate change; (4) ecology and evolution of infectious disease; (5) invasive species; and (6) land use and habitat alteration. Themes such as data sharing, multidisciplinary collaboration, and the development of technologies for sensing, forecasting, and visualizing biological information are central to the NEON concept. Development of the NEON science plan and the design of the network itself are proceeding through a variety of workshops and community planning meetings. A national project office is expected to form toward the end of 2004 to lead the development and creation of NEON. Ultimately, the project office will reside within an independent national organization devoted to the coordinated operation of NEON for the scientific community.

  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 Astrophysics Data System (ADS)

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

    2009-12-01

    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 (˜μs 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 Ω0/2 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 μs. 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. 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.

  19. An annotated checklist of the horse flies, deer flies, and yellow flies (Diptera: Tabanidae) of Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The family Tabanidae includes the horse flies, deer flies, and yellow flies and is considered a significant pest of livestock throughout the United States, including Florida. Tabanids can easily become a major pest of man, especially salt marsh species which are known to readily feed on humans and o...

  20. Laboratory evaluation of novaluron for controlling larval horn flies, house flies, and stable flies (Diptera: Muscidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A granular formulation of novaluron (Novaluron 0.2G, 0.2% AI), a newer benzoylphenyl urea insecticide, was evaluated for its efficacy in controlling the larval stage of horn flies, Haematobia irritans (Linnaeus), house flies, Musca domestica Linnaeus, and stable flies, Stomoxys calcitrans (Linnaeus)...

  1. A cost-effective approach to microporate mammalian cells with the Neon Transfection System.

    PubMed

    Brees, Chantal; Fransen, Marc

    2014-12-01

    Electroporation is one of the most efficient nonviral methods for transferring exogenous DNA into mammalian cells. However, the relatively high costs of electroporation kits and reagents temper the routine use of this fast and easy to perform technique in many laboratories. Several years ago, a new flexible and easy to operate electroporation device was launched under the name Neon Transfection System. This device uses specialized pipette tips containing gold-plated electrodes as electroporation chamber. Here we report a protocol to regenerate these expensive tips as well as some other Neon kit accessories, thereby reducing the cost of electroporation at least 10-fold. PMID:25172131

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

    PubMed

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

    2013-04-26

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

  3. Cooperative lifetime reduction of single acene molecules attached to the surface of neon clusters

    NASA Astrophysics Data System (ADS)

    Müller, Markus; Izadnia, Sharareh; Vlaming, Sebastiaan M.; Eisfeld, Alexander; LaForge, Aaron; Stienkemeier, Frank

    2015-09-01

    Tetracene and pentacene molecules attached to the surface of neon clusters have been spectroscopically investigated. The fluorescence spectra indicate that the molecules are immobilized on the surface and, to a large extent, do not form complexes. By varying the number of attached molecules, laser power, or neon cluster size, we find a systematic fluorescence lifetime reduction up to a factor of 20 indicating a cooperative coupling in our system. For averaged intermolecular distances greater than 33 Å, we attribute the reduction in fluorescence lifetime to Dicke superradiance, while for smaller intermolecular distances, nonradiative decay mechanisms cause additional lifetime reduction.

  4. Boundary conditions on the early Sun from ancient cosmogenic neon in meteorites

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    Isotopic analysis of neon from individual grains of the meteorites Murchison (CM) and Kapoeta (howardite) shows large enrichments of cosmogenic neon in grains with solar flare tracks. The quantity of this component is incompatible with galactic cosmic ray or solar cosmic ray irradiation under present conditions and is attributed to irradiation by energetic flares from an early active Sun. Handpicked grains from each meteorite were grouped according to the presence or absence of solar flare heavy ion tracks, and these four samples were analyzed with an ion counting noble gas mass spectrometer.

  5. 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.

  6. Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers.

    PubMed

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

    2009-05-01

    Squid paralarvae (hatchlings) rely predominantly on a pulsed jet for locomotion, distinguishing them from the majority of aquatic locomotors at low/intermediate Reynolds numbers (Re), which employ oscillatory/undulatory modes of propulsion. Although squid paralarvae may delineate the lower size limit of biological jet propulsion, surprisingly little is known about the hydrodynamics and propulsive efficiency of paralarval jetting within the intermediate Re realm. To better understand paralarval jet dynamics, we used digital particle image velocimetry (DPIV) and high-speed video to measure bulk vortex properties (e.g. circulation, impulse, kinetic energy) and other jet features [e.g. average and peak jet velocity along the jet centerline (U(j) and U(jmax), respectively), jet angle, jet length based on the vorticity and velocity extents (L(omega) and L(V), respectively), jet diameter based on the distance between vorticity peaks (D(omega)), maximum funnel diameter (D(F)), average and maximum swimming speed (U and U(max), respectively)] in free-swimming Doryteuthis pealeii paralarvae (1.8 mm dorsal mantle length) (Re(squid)=25-90). Squid paralarvae spent the majority of their time station holding in the water column, relying predominantly on a frequent, high-volume, vertically directed jet. During station holding, paralarvae produced a range of jet structures from spherical vortex rings (L(omega)/D(omega)=2.1, L(V)/D(F)=13.6) to more elongated vortex ring structures with no distinguishable pinch-off (L(omega)/D(omega)=4.6, L(V)/D(F)=36.0). To swim faster, paralarvae increased pulse duration and L(omega)/D(omega), leading to higher impulse but kept jet velocity relatively constant. Paralarvae produced jets with low slip, i.e. ratio of jet velocity to swimming velocity (U(j)/U or U(jmax)/U(max)), and exhibited propulsive efficiency [eta(pd)=74.9+/-8.83% (+/-s.d.) for deconvolved data] comparable with oscillatory/undulatory swimmers. As slip decreased with speed

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  8. Test What You Fly?

    NASA Technical Reports Server (NTRS)

    Margolies, Don

    2002-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We analyzed the dc SQUID with voltage feedback circuit (VFC) and a low-noise room-temperature preamplifier to evaluate the feasibility of a low-noise SQUID direct-coupled readout scheme (DRS), possibly eliminating the need for a two-stage scheme employing a SQUID preamplifier. The passive VFC, connected in parallel to the SQUID, consists of a resistor Rs in series with an inductor L s. This inductor is coupled to the SQUID by a mutual inductance Ms. The purpose of the VFC is to increase the SQUID’s flux-to-voltage transfer coefficient ∂V/∂Φ, thus reducing the preamplifier noise contribution δΦpreamp. However, at the same time, VFC introduces the thermal noise of Rs, δΦR, which may not be negligible. Generally, the noise of the readout scheme, δΦreadout, may thus include both δΦpreamp and δΦR, i.e., δΦreadout2 = δΦpreamp2 + δΦR2. To characterize the SQUID operation with VFC we introduced two dimensionless parameters, r = Rs/Rd and Δ = (M s/Mdyn) - (Rs/R d), where Rd and Mdyn = 1/(∂i/∂Φ) are dynamic properties of the SQUID itself. For assumed intrinsic SQUID parameters, we then numerically analyzed the dependence of δΦreadout noise components on r and Δ to determine their suitable ranges and the minimum of δΦreadout. To verify our analysis, we experimentally characterized, in liquid helium, three niobium SQUIDs with VFC, having suitably chosen r and Δ. The measured SQUID system flux noise was on the order of 1 μΦ0/√Hz, comparable to the intrinsic noise of the SQUID itself. The deduced equivalent voltage noise was comparable to that of a SQUID preamplifier in the two-stage readout. Simple single-stage ultra-low-noise SQUID DRS readout was thus demonstrated.

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

  11. Fly-scan ptychography

    DOE PAGESBeta

    Huang, Xiaojing; Lauer, Kenneth; Clark, Jesse N.; Xu, Weihe; Nazaretski, Evgeny; Harder, Ross; Robinson, Ian K.; Chu, Yong S.

    2015-03-13

    We report an experimental ptychography measurement performed in fly-scan mode. With a visible-light laser source, we demonstrate a 5-fold reduction of data acquisition time. By including multiple mutually incoherent modes into the incident illumination, high quality images were successfully reconstructed from blurry diffraction patterns. This approach significantly increases the throughput of ptychography, especially for three-dimensional applications and the visualization of dynamic systems.

  12. Flying Saucer? Aliens?

    NASA Technical Reports Server (NTRS)

    1961-01-01

    No, it's not a flying saucer, it is the domed top to a 70 foot long vacuum tank at the Lewis Research Center's Electric Propulsion Laboratory, Cleveland, Ohio. The three technicians shown here in protective clothing had just emerged from within the tank where they had been cleaning in the toxic mercury atmosphere, left after ion engine testing in the tank. Lewis has since been renamed the John H. Glenn Research Center.

  13. Fly-scan ptychography

    PubMed Central

    Huang, Xiaojing; Lauer, Kenneth; Clark, Jesse N.; Xu, Weihe; Nazaretski, Evgeny; Harder, Ross; Robinson, Ian K.; Chu, Yong S.

    2015-01-01

    We report an experimental ptychography measurement performed in fly-scan mode. With a visible-light laser source, we demonstrate a 5-fold reduction of data acquisition time. By including multiple mutually incoherent modes into the incident illumination, high quality images were successfully reconstructed from blurry diffraction patterns. This approach significantly increases the throughput of ptychography, especially for three-dimensional applications and the visualization of dynamic systems. PMID:25766519

  14. Superconductive combinational logic circuit using magnetically coupled SQUID array

    NASA Astrophysics Data System (ADS)

    Yamanashi, Y.; Umeda, K.; Sai, K.

    2010-11-01

    In this paper, we propose the development of superconductive combinational logic circuits. One of the difficulties in designing superconductive single-flux-quantum (SFQ) digital circuits can be attributed to the fundamental nature of the SFQ circuits, in which all logic gates have latching functions and are based on sequential logic. The design of ultralow-power superconductive digital circuits can be facilitated by the development of superconductive combinational logic circuits in which the output is a function of only the present input. This is because superconductive combinational logic circuits do not require determination of the timing adjustment and clocking scheme. Moreover, semiconductor design tools can be used to design digital circuits because CMOS logic gates are based on combinational logic. The proposed superconductive combinational logic circuits comprise a magnetically coupled SQUID array. By adjusting the circuit parameters and coupling strengths between neighboring SQUIDs, fundamental combinational logic gates, including the AND, OR, and NOT gates, can be built. We have verified the accuracy of the operations of the fundamental logic gates by analog circuit simulations.

  15. 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.

  16. 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.

  17. SQUID-based beam position monitoring for proton EDM experiment

    NASA Astrophysics Data System (ADS)

    Haciomeroglu, Selcuk

    2014-09-01

    One of the major systematic errors in the proton EDM experiment is the radial B-field, since it couples the magnetic dipole moment and causes a vertical spin precession. For a proton with EDM at the level of 10-29 e.cm, 0.22 pG of B-field and 10.5 MV/m of E-field cause same vertical spin precession. On the other hand, the radial B-field splits the counter-rotating beams depending on the vertical focusing strength in the ring The magnetic field due to this split modulated at a few kHz can be measured by a SQUID-magnetometer. This measurement requires the B-field to be kept less than 1 nT everywhere around the ring using shields of mu-metal and aluminum layers. Then, the SQUID measurements involve noise from three sources: outside the shields, the shields themselves and the beam. We study these three sources of noise using an electric circuit (mimicking the beam) inside a magnetic shielding room which consists two-layers of mu-metal and an aluminum layer.

  18. Structural health monitoring of materials by high critical temperature SQUID

    NASA Astrophysics Data System (ADS)

    Valentino, M.; Ruosi, A.; Peluso, G.; Pepe, G. P.

    2002-08-01

    Nowadays, tailoring the material properties is essential for advanced product design in engineering systems. The need to provide key information about micro- and macro-structural behaviour of materials, without destructively sectioning the sample, has spurred the development of nondestructive evaluation methodologies. These techniques are required during material production, quality testing of components during manufacturing, and in-service inspection of structural integrity. To ensure the highest possible operational safety along with an economic efficiency, it is necessary to carry out inspections with a high sensitivity and a proven reliability. Due to its unparalleled magnetic field sensitivity over a wide frequency range and large dynamic range, SQUID-based nondestructive evaluation has unique advantages for materials and structures characterization. We will present an overview of eddy-current nondestructive analysis utilizing high Tc SQUIDs with an emphasis on examples relevant to the aeronautical industry. These include the detection of deep-lying defects in multi-layer structures of Al-Ti alloys and damage of extremely lightweight graphite/epoxy composites. Both of these can be successfully treated by this approach where conventional electromagnetic probes often fail. In addition some results based on the volume integral formulation, successfully developed to simulate the response of the system to different type of flaws in Al-alloy planar structures and to solve the inverse electromagnetic problem, will be shown.

  19. Progress toward observation of quantum interference of currents in an Atom SQUID

    NASA Astrophysics Data System (ADS)

    Ryu, Changhyun; Samson, E. Carlo; Boshier, Malcolm

    2016-05-01

    Quantum interference of currents was first observed in a superconducting loop with two Josephson junctions, leading to the name ``SQUID'' for this device. This interference effect has been used to develop extremely sensitive magnetometers. The Atom SQUID, an analogous device based on ultracold atoms, has been developed recently to study SQUID physics in a device offering a better understanding of the underlying microscopic dynamics. Although many exciting experiments have been done with Atom SQUIDs, the quantum interference of currents has not yet been observed. In analogy with the SQUID magnetometer, it should be possible to use the quantum interference effect in an Atom SQUID to measure rotation, which may lead to the development of a sensitive gyroscope. In a previous experiment, we showed Josephson effects with an atom SQUID by observing the change from the dc Josephson regime to the ac Josephson regime by measurement of the critical atom number for this transition. Quantum interference should cause this critical atom number to vary with rotation rate. We have simulated this system with the Gross-Pitaevski Equation and found the expected oscillatory change of the critical atom number. We will present this simulation result and report the current status of our experiment to

  20. 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.

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

    PubMed Central

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

    2013-01-01

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

  2. Linear Zeff scaling of the anomalous inward drift and enhanced proportionality factor during neon inflow

    NASA Astrophysics Data System (ADS)

    Becker, G.

    1996-12-01

    The origin of density profile peaking due to impurity puffing and the anomalous particle pinch are explored by computer simulations with special versions of the 1.5-D BALDUR predictive transport code. Transport analysis of high density H mode plasmas with strong neon puffing and density profile peaking yields a new scaling law for the anomalous inward drift velocity, upsilon in(x)=Cupsilon 2xD(x)/( rho wxs2), with C upsilon =FZeff(x), where D is the diffusion coefficient. This scaling implies that upsilon in/D varies as Zeff and results in upsilon in varies as Zeff since D is found to be independent of this parameter. The strong density profile peaking is caused by the increase in Zeff and by an enhanced factor F discovered during neon puffing. The time evolution of F correlates with the neon influx rate, but not with the neon content and the power losses due to line radiation and ionization. The factor F rises with growing influx rate and depends non-locally on the region where inelastic collisions prevail. One plausible mechanism for the enhancement of F is that inelastic collisions between fluctuating electrons and impurity ions change the dissipative part of the fluctuating electron distribution

  3. 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.

  4. A theoretical study of the rovibrational levels of the bosonic van der Waals neon trimer.

    PubMed

    Salci, Moses; Levin, Sergey B; Elander, Nils; Yarevsky, Evgeny

    2008-10-01

    The eigenenergies and root mean square radii of the rovibrational levels (J = 0-3) of the weakly bound bosonic van der Waals neon trimer were calculated using a full angular momentum three-dimensional finite element method. The differing results of three previous studies for zero angular momentum are discussed, explained, and compared with the results presented here. PMID:19045087

  5. X-ray diffraction and equation of state of solid neon to 110 GPa

    NASA Astrophysics Data System (ADS)

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

    1989-06-01

    Solid neon was compressed under static conditions at 300 K to pressures in the 100 GPa (megabar) range using diamond-anvil cell techniques. The crystal structure and P-V equation of state were determined by energy-dispersive x-ray diffraction with microcollimated synchrotron radiation. Pressures were determined from ruby fluorescence spectra and from x-ray diffraction of tungsten powder contained within the sample. Solid neon remains an insulator with the fcc structure to the maximum pressure of 110 GPa at 300 K, where the compression V/V0 is 0.28. The 300-K P-V isotherm measured at high pressure is in excellent agreement with the results of electronic structure calculations but is incorrectly described by pure pair potentials recently developed for neon. These results indicate that there is a significant softening of the material by many-body interactions at high pressures. Finally, the measurements of ruby fluorescence and tungsten x-ray diffraction in the neon medium obtained in this study provide an extension of the quasihydrostatic ruby pressure scale above 100 GPa.

  6. X-ray diffraction and equation of state of solid neon to 110 GPa

    SciTech Connect

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

    1989-06-01

    Solid neon was compressed under static conditions at 300 K to pressures in the 100 GPa (megabar) range using diamond-anvil cell techniques. The crystal structure and /ital P/-/ital V/ equation of state were determined by energy-dispersive x-ray diffraction with microcollimated synchrotron radiation. Pressures were determined from ruby fluorescence spectra and from x-ray diffraction of tungsten powder contained within the sample. Solid neon remains an insulator with the fcc structure to the maximum pressure of 110 GPa at 300 K, where the compression /ital V///ital V//sub 0/ is 0.28. The 300-K /ital P/-/ital V/ isotherm measured at high pressure is in excellent agreement with the results of electronic structure calculations but is incorrectly described by pure pair potentials recently developed for neon. These results indicate that there is a significant softening of the material by many-body interactions at high pressures. Finally, the measurements of ruby fluorescence and tungsten x-ray diffraction in the neon medium obtained in this study provide an extension of the quasihydrostatic ruby pressure scale above 100 GPa.

  7. Belowground Biomass Sampling to Estimate Fine Root Mass across NEON Sites

    NASA Astrophysics Data System (ADS)

    Spencer, J. J.; Meier, C. L.; Abercrombie, H.; Everhart, J. C.

    2013-12-01

    Production of belowground biomass is an important and relatively uncharacterized component of the net primary productivity (NPP) of ecosystems. Fine root productivity makes up a significant portion of total belowground production because fine roots turn over rapidly, and therefore contribute disproportionately to annual estimates of belowground net primary productivity (BNPP). One of the major goals of the National Ecological Observatory Network (NEON) is to quantify above- and below-ground NPP at 60 sites within 20 different eco-climactic regions. NEON's Terrestrial Observation System will carry out belowground biomass sampling throughout the life of the observatory to estimate fine root production. However, belowground biomass sampling during NEON operations will be constrained to a maximum depth of 50cm. This limited depth range leaves the question of what proportion of total fine root mass is being collected and how to optimally characterize belowground biomass given sampling depth limitations. During the construction period, NEON is characterizing fine root biomass distribution at depth down to 2m at each site, as well as physical and chemical properties in each soil horizon. Each sampling unit is a pit (2m deep and approximately 1.5m wide), dug in the site's dominant vegetation type where fine root biomass sampling will also occur during Operations. To sample fine root biomass in each pit, soil samples of a known volume are taken from three vertical profiles down the face of the pit. Samples are then wet sieved to extract fine root mass, and roots are dried at 65°C for 48 hours and then weighed. The soil pit data are used to estimate the proportion of total fine root biomass from each site as a function of depth. Non-linear curves are fitted to the data to calculate total fine root mass at depth and to provide estimates of the proportion of the total fine root mass that is sampled at each site during NEON's 30 year operational sampling. The belowground

  8. 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

  9. Auditory system of fruit flies.

    PubMed

    Ishikawa, Yuki; Kamikouchi, Azusa

    2016-08-01

    The fruit fly, Drosophila melanogaster, is an invaluable model for auditory research. Advantages of using the fruit fly include its stereotyped behavior in response to a particular sound, and the availability of molecular-genetic tools to manipulate gene expression and cellular activity. Although the receiver type in fruit flies differs from that in mammals, the auditory systems of mammals and fruit flies are strikingly similar with regard to the level of development, transduction mechanism, mechanical amplification, and central projections. These similarities strongly support the use of the fruit fly to study the general principles of acoustic information processing. In this review, we introduce acoustic communication and discuss recent advances in our understanding on hearing in fruit flies. This article is part of a Special Issue entitled . PMID:26560238

  10. 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.

  11. Design of frequency domain multiplexing of TES signals by multi-input SQUIDs

    NASA Astrophysics Data System (ADS)

    Yamasaki, Noriko Y.; Masui, Kensuke; Mitsuda, Kazuhisa; Morooka, Toshimitsu; Nakayama, Satoshi; Takei, Yoh

    2006-04-01

    In frequency-domain Superconducting Quantum Interference Device (SQUID) multiplexing for Transition Edge Sensor (TES) readout, a magnetic field summation method utilizing multi-input SQUIDs has a fundamental merit of small degradation of signal-to-noise ratio. Independent wiring without common impedance avoids the cross talk current, and the current induced by magnetic coupling between the input coils is suppressed by the direct feedback at the summing point. A multi-input SQUID which has 8 input coils has been fabricated and requirements for Flux Locked Loop (FLL) circuits are summarized.

  12. Frequency-domain multiplex with eight-input SQUID and readout electronics over 1 MHz

    NASA Astrophysics Data System (ADS)

    Masui, K.; Takei, Y.; Ikeda, H.; Kimura, S.; Mitsuda, K.; Yamasaki, N. Y.

    2006-04-01

    In a magnetic summation method, TES and SQUID driving circuits are isolated and thus small crosstalk and stray impedance are expected. Since a FLL circuit with a large bandwidth and a small noise level is required for a SQUID, we designed and produced an electronics to meet our design of multiplexing with an 8-input SQUID. The FLL circuit achieved an open loop-gain bandwidth product of 8 MHz with 1 m wire length, which is enough for a TES to be operated with a bias current of 70 μA, and a noise level of 30 pA/√{Hz}.

  13. Magnetic calorimeter with a SQUID for detecting weak radiations and recording the ultralow energy release

    SciTech Connect

    Golovashkin, Aleksander I; Zherikhina, L N; Kuleshova, G V; Tskhovrebov, A M; Izmailov, G N

    2006-12-31

    The scheme of a magnetic calorimeter for recording extremely low energy releases is developed. The calorimeter is activated by the method of adiabatic demagnetisation and its response to the energy release is measured with a superconducting quantum interference device (SQUID). The estimate of the ultimate sensitivity of the calorimeter with the SQUID demonstrates the possibilities of its application for detecting ultralow radiation intensity, recording single X-ray quanta in the proportional regime and other events with ultralow energy releases. The scheme of the calorimeter with the SQUID on matter waves in superfluid {sup 4}He is proposed. (radiation detectors)

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

    SciTech Connect

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

    2009-10-21

    Axions in the {mu}eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. The first result from such an axion search using a superconducting first-stage amplifier (SQUID) is reported. The SQUID amplifier, replacing a conventional GaAs field-effect transistor amplifier, successfully reached axion-photon coupling sensitivity in the band set by present axion models and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.

  15. 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.

  16. 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

  17. Blood feeding behavior of the stable fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stable fly is a fly that looks similar to a house fly but both sexes are blood feeders. Blood is required for successful fertilization and development of eggs. Bites are painful but there is usually no pain after the fly stops feeding. The stable fly is a persistent feeder and will continue trying t...

  18. The FlyBar: Administering Alcohol to Flies

    PubMed Central

    van der Linde, Kim; Fumagalli, Emiliano; Roman, Gregg; Lyons, Lisa C.

    2014-01-01

    Fruit flies (Drosophila melanogaster) are an established model for both alcohol research and circadian biology. Recently, we showed that the circadian clock modulates alcohol sensitivity, but not the formation of tolerance. Here, we describe our protocol in detail. Alcohol is administered to the flies using the FlyBar. In this setup, saturated alcohol vapor is mixed with humidified air in set proportions, and administered to the flies in four tubes simultaneously. Flies are reared under standardized conditions in order to minimize variation between the replicates. Three-day old flies of different genotypes or treatments are used for the experiments, preferably by matching flies of two different time points (e.g., CT 5 and CT 17) making direct comparisons possible. During the experiment, flies are exposed for 1 hr to the pre-determined percentage of alcohol vapor and the number of flies that exhibit the Loss of Righting reflex (LoRR) or sedation are counted every 5 min. The data can be analyzed using three different statistical approaches. The first is to determine the time at which 50% of the flies have lost their righting reflex and use an Analysis of the Variance (ANOVA) to determine whether significant differences exist between time points. The second is to determine the percentage flies that show LoRR after a specified number of minutes, followed by an ANOVA analysis. The last method is to analyze the whole times series using multivariate statistics. The protocol can also be used for non-circadian experiments or comparisons between genotypes. PMID:24895004

  19. Ameliorative effect of fly ashes

    SciTech Connect

    Bhumbla, D.K.

    1991-01-01

    Agronomic effectiveness and environmental impact of fly ashes used to reclaim pyritic acid mine spoils were investigated in the laboratory and field. Mine spoils at two abandoned sites were amended with three rates of fly ash, three rates of rock phosphate, and seeded with alfalfa and wheat. Application of fly ash decreased bulk density and increased moisture retention capacity of spoils. Fly ash application reduced cation exchange capacity, acidity, toxic levels of Al, Fe, and Mn in soils by buffering soil pH at 6.5, and retarded pyrite oxidation. The reduction in cation exchange capacity was compensated by release of plant nutrients through diffusion and dissolution of plerospheres in fly ash. Improvement of spoil physical, chemical and microbial properties resulted in higher yield, more nitrogen fixation, and utilization of P from rock phosphate by alfalfa. Laboratory investigations demonstrated that neutralization potential and the amounts of amorphous oxides of iron were more important for classifying fly ashes than the total elemental analysis presently used in a taxonomic classification system. Contamination of the food chain through plant removal of Mo and As in fly ash treated mine spoils was observed only for Mo and only for the first year of cropping. Plant available As and Mo decreased with time. Laboratory leaching and adsorption studies and a field experiment showed that trace metals do not leach from fly ashes at near neutral pH and more oxyanions will leach from fly ashes with low neutralization potential and low amounts of amorphous oxides of iron.

  20. NAVTOLAND and flying qualities

    NASA Technical Reports Server (NTRS)

    Momiyama, T. S.

    1977-01-01

    The V/STOL operational capability is reviewed with emphasis on pilot workload and all-weather landing guidance systems. A research and development program to correlate and integrate the development of all systems and techniques involved in enabling the pilot to fly V/STOL aircraft onto ships and tactical sites is described. Aircraft design parameters that affect its control in the vertical takeoff and landing flight regimes are emphasized. Topics considered include: (1) integrated flight controls and displays; (2) low speed sensor; (3) air traffic control appraoch and landing guidance systems; (4) visual landing aids; (5) ground effect induced thrust variation problems; and (6) handling qualities.

  1. Flying wires at Fermilab

    SciTech Connect

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

    1989-03-01

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

  2. [Otorhinolaryngologic diseases and flying].

    PubMed

    Moser, M

    2002-01-01

    Physiological and pathological aspects of pressure changes, noise, acceleration, variation of temperature, low humidity, stress and time differences in flight passengers and aircrew are discussed. Typical ear, nose, and throat clinic (ENT)-cases such as tubal function disturbances, barotrauma, hypacusis, sudden hearing loss, tinnitus, acute and chronic middle ear diseases, post ear surgery conditions, hearing aids, vertigo and motion sickness are described. The influence on flying of acute and chronic affections of the paranasal sinuses, nasal septal deviation and allergy are listed. The problem of transport of ENT-incapacitated passengers in commercial aircrafts and ambulance jets are dealt with. PMID:12385068

  3. Flying over decades

    NASA Astrophysics Data System (ADS)

    Hoeller, Judith; Issler, Mena; Imamoglu, Atac

    Levy flights haven been extensively used in the past three decades to describe non-Brownian motion of particles. In this presentation I give an overview on how Levy flights have been used across several disciplines, ranging from biology to finance to physics. In our publication we describe how a single electron spin 'flies' when captured in quantum dot using the central spin model. At last I motivate the use of Levy flights for the description of anomalous diffusion in modern experiments, concretely to describe the lifetimes of quasi-particles in Josephson junctions. Finished PhD at ETH in Spring 2015.

  4. Flying by Titan

    NASA Technical Reports Server (NTRS)

    Pelletier, Frederic J.; Antreasian, Peter G.; Ardalan, Shadan M.; Criddle, Kevin E.; Ionasescu, Rodica; Jacobson, Robert A.; Jones, Jeremy B.; Parcher, Daniel W.; Roth, Duane C.; Thompson, Paul F.; Vaughan, Andrew T.

    2008-01-01

    The Cassini spacecraft encounters the massive Titan about once every month. These encounters are essential to the mission as Titan is the only satellite of Saturn that can provide enough gravity assist to shape the orbit tour and allow outstanding science for many years. From a navigation point of view, these encounters provide many challenges, in particular those that fly close enough to the surface for the atmospheric drag to perturb the orbit. This paper discusses the dynamics models developed to successfully navigate Cassini and determine its trajectory. This includes the moon's gravity pull with its second degree zonal harmonics J2, the attitude thrust control perturbations and the acceleration of drag.

  5. Flying in, Flying out: Offshore Teaching in Higher Education

    ERIC Educational Resources Information Center

    Seah, Wee Tiong; Edwards, Julie

    2006-01-01

    This paper discusses the relatively new phenomenon of university education faculties offering offshore education. The analogy, "flying in, flying out" captures the intensity of such offshore experiences for visiting academics, and contrasts their professional experiences against expatriate academics. This paper reports on case studies of two…

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

    NASA Astrophysics Data System (ADS)

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

    2006-05-01

    SQUID (superconducting quantum interference device) microscopes are versatile instruments for biosensing applications, in particular for magnetic nanoparticle detection in immunoassay experiments. We are developing a SQUID microscope based on an HTS rf SQUID magnetometer sensor with a substrate resonator. For the cryogenic set-up, a configuration was realized in which the cryostat is continuously refilled and kept at a constant liquid nitrogen level by an isolated tube connection to a large liquid nitrogen reservoir. The SQUID is mounted on top of a sapphire finger, connected to the inner vessel of the stainless steel cryostat. The vacuum gap between the cold SQUID and room temperature sample is adjusted by the precise approach of a 50 µm thin sapphire window using a single fine thread wheel. We investigated possible sensing tip configurations and different sensor integration techniques in order to achieve an optimized design. A new scheme of coupling the rf SQUID from its back to a SrTiO3 substrate resonator was adopted for the purpose of minimization of the sensor-to-sample spacing. By SQUID substrate thinning and washer size reduction, the optimum coupling conditions for back coupling were determined for different rf SQUID magnetometers prepared on LaAlO3 and SrTiO3 substrates. The SQUID microscope system is characterized with respect to its spatial resolution and its magnetic field noise. The SQUID microscope instrument will be used for magnetic nanoparticle marker detection.

  7. Examination of a Digital FLL System Design for SQUIDs

    NASA Astrophysics Data System (ADS)

    Oyama, Daisuke; Kobayashi, Koichiro; Simizu, Takayuki; Yoshizawa, Masahito; Uchikawa, Yoshinori

    Biomagnetic field measurements in unshielded environment require both large dynamic range and high slew rate. Noise amplitudes at 50Hz and under 10 Hz of significantly more than 1μT are not at all exotic in an industrial or a hospital environment. A digital FLL (D-FLL) system for a SQUID magnetometer has high resolution and large dynamic range of magnetic field. Slew rate of a D-FLL system by using a double-counter is limited by its digital feedback loop. It can increase the slew rate that optimum feedback loop gain is divided into an analog preamplifier and a digital amplifier on a microcontroller. We show design method of their amplifiers. The slew rate of a D-FLL system with optimum amplifiers is 483 Φ0/s , and its noise level is about 50.0fT√Hz@120Hz.

  8. Scanning SQUID microscopy of SFS π-Josephson junction arrays

    NASA Astrophysics Data System (ADS)

    Stoutimore, M. J. A.; Oboznov, V. A.

    2005-03-01

    We use a Scanning SQUID Microscope to image the magnetic flux distribution in arrays of SFS (superconductor-ferromagnet-superconductor) Josephson junctions. The junctions are fabricated with barrier thickness such that they undergo a transition to a π-junction state at a temperature Tπ 2-4 K. In arrays with cells that have an odd number of π-junctions, we observe spontaneously generated magnetic flux in zero applied magnetic field. We image both fully-frustrated arrays and arrays with non-uniform frustration created by varying the number of π-junctions in the cells. By monitoring the onset of spontaneous flux as a function of temperature near Tπ,^ we estimate the uniformity of the junction critical currents.

  9. 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.

  10. 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. ); Schneider, S.; Seifert, H.; Reichenberger, H.; Abraham-Fuchs, K. )

    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).

  11. The Transition from Stiff to Compliant Materials in Squid Beaks

    NASA Astrophysics Data System (ADS)

    Miserez, Ali; Schneberk, Todd; Sun, Chengjun; Zok, Frank W.; Waite, J. Herbert

    2008-03-01

    The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.

  12. The Transition from Stiff to Compliant Materials in Squid Beaks

    PubMed Central

    Miserez, Ali; Schneberk, Todd; Sun, Chengjun; Zok, Frank W.; Waite, J. Herbert

    2009-01-01

    The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-l-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications. PMID:18369144

  13. The transition from stiff to compliant materials in squid beaks.

    PubMed

    Miserez, Ali; Schneberk, Todd; Sun, Chengjun; Zok, Frank W; Waite, J Herbert

    2008-03-28

    The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications. PMID:18369144

  14. 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.

  15. Synchronization of networked Jahn-Teller systems in SQUIDs

    NASA Astrophysics Data System (ADS)

    Gül, Yusuf

    2016-06-01

    We consider the nonlinear effects in a Jahn-Teller (JT) system of two coupled resonators interacting simultaneously with a flux qubit using coupled SQUIDs. A two-frequency description of JT system that inherits the networked structure of both nonlinear Josephson junctions and harmonic oscillators is employed to describe the synchronous structures in a multifrequency scheme. Eigenvalue spectrum is used to show the switch between the effective single mode and two mode configuration in terms of frequency difference. The Rabi supersplitting is investigated by the spectral response of JT systems in different coupling regimes. Second-order coherence functions are employed to investigate antibunching effects in resonator mode. Synchronous structure between correlations of privileged mode and qubit is obtained in localization-delocalization and photon blockade regime controlled by the population imbalance.

  16. Fly ash quality and utilization

    SciTech Connect

    Barta, L.E.; Lachner, L.; Wenzel, G.B.; Beer, M.J.

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  17. High-Tc SQUID Magnetometers for Industrial Applications

    NASA Astrophysics Data System (ADS)

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

    1998-03-01

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

  18. 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.

  19. Flies, clocks and evolution.

    PubMed Central

    Rosato, E; Kyriacou, C P

    2001-01-01

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

  20. Physics of flying

    NASA Astrophysics Data System (ADS)

    Vetrone, Jim

    2015-05-01

    Column editor's note: As the school year comes to a close, it is important to start thinking about next year. One area that you want to consider is field trips. Many institutions require that teachers plan for a field trip well in advance. Keeping that in mind, I asked Jim Vetrone to write an article about the fantastic field trip he takes his AP Physics students on. I had the awesome opportunity to attend a professional development day that Jim arranged at iFLY in the Chicago suburbs. The experience of "flying" in a wind tunnel was fabulous. Equally fun was watching the other physics teachers come up with experiments to have the professional "flyers" perform in the tube. I could envision my students being similarly excited about the experience and about the development of their own experiments. After I returned to school, I immediately began the process of trying to get this field trip approved for the 2015-16 school year. I suggest that you start your process as well if you hope to try a new field trip next year. The key to getting the approval, in my experience, is submitting a proposal early that includes supporting documentation from sources. Often I use NGSS or state standards as justifications for my field trips. I have also quoted College Board expectations for AP Physics 1 and 2 in my documents when requesting an unusual field trip.

  1. Performance of high-TC dc SQUID magnetometers for use in a magnetically disturbed environment

    NASA Astrophysics Data System (ADS)

    Kim, I. S.; Yu, K. K.; Lee, Y. H.; Kim, K. W.; Park, Y. K.

    2004-06-01

    YBCO dc SQUID magnetometers based on bicrystal Josephson junctions on 10 mm × 10 mm STO substrates have been fabricated. We have designed three different types of pickup coils for the SQUID magnetometers, i.e., solid-type, 12 and 16 parallel loops with 50 m line width to test performances of the SQUIDs for use in a magnetically disturbed environment. Magnetometer with 16-parallel-loop pickup coil exhibit most stable FLL operation under external dc magnetic field. Finally, we could obtain optimised direct coupled YBCO SQUID magnetometer design having flux transfer coefficient B of 4.5 nT/0 and magnetic field noise BN of 30 fT/Hz1/2 measured at 100 Hz.

  2. Microwave Reflectometry Measurements of Flux States of a dc SQUID Phase Qubit

    NASA Astrophysics Data System (ADS)

    Cooper, B. K.; Lewis, R. M.; Dutta, S. K.; Palomaki, T. A.; Przybysz, Anthony; Kwon, H.; Paik, Hanhee; Anderson, J. R.; Lobb, C. J.; Wellstood, F. C.

    2008-03-01

    We examine microwave reflectometry readout of a dc SQUID phase qubit. Our device is a Nb/AlOx/Nb SQUID fabricated by Hypres with loop inductance of 1.3 nH and symmetric junction critical currents of approximately 5 μA. The SQUID is current and flux biased, with one junction used as the qubit and the other used to provide isolation. The isolation junction is shunted by a large capacitor to depress its plasma frequency to about 1.5 GHz. This frequency can be shifted by flux-induced circulating current in the SQUID loop, allowing us to determine which flux state we are in by making reflectometry measurements of the resonant behavior of the isolation junction. The utility of this measurement for qubit state readout is discussed.

  3. Reflectometry measurements of 1/f noise in SQUID phase qubits at mK temperatures

    NASA Astrophysics Data System (ADS)

    Cooper, B. K.; Lewis, R. M.; Palmer, B. S.; Zaretskey, V.; Przybysz, A. J.; Kwon, H.; Anderson, J. R.; Lobb, C. J.; Wellstood, F. C.

    2009-03-01

    We measure 1/f noise spectra in dc SQUID phase qubits using a microwave reflectometry technique. One of the SQUID junctions is shunted by a large capacitor, forming a microwave frequency resonator biased and driven to show nonlinear response, typically at 1.5 GHz. This nonlinearity means small current or flux fluctuations produce large changes in reflected phase which we can measure using homodyne detection. Measurements from aluminum qubits on sapphire are compared to previous measurements of 1/f flux noise in SQUIDs and a similarly designed Nb/AlOx/Nb on silicon dc SQUID qubit fabricated by Hypres; data was taken at temperatures ranging from 50 mK to 500 mK.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2012-04-23

    Little is known about the reproductive habits of deep-living squids. Using remotely operated vehicles in the deep waters of the Monterey Submarine Canyon, we have found evidence of mating, i.e. implanted sperm packages, on similar body locations in males and females of the rarely seen mesopelagic squid Octopoteuthis deletron. Equivalent numbers of both sexes were found to have mated, indicating that male squid routinely and indiscriminately mate with both males and females. Most squid species are short-lived, semelparous (i.e. with a single, brief reproductive period) and promiscuous. In the deep, dark habitat where O. deletron lives, potential mates are few and far between. We suggest that same-sex mating behaviour by O. deletron is part of a reproductive strategy that maximizes success by inducing males to indiscriminately and swiftly inseminate every conspecific that they encounter. PMID:21937492

  6. Time-Resolved SQUID Sensor with a Nyquist Frequency up to 25 GHz

    NASA Astrophysics Data System (ADS)

    Cui, Z.; Wang, Y. H.; Kratz, P.; Rosenberg, A. J.; Watson, C. A.; Sochnikov, I.; Fung, Y.-K.-K.; Gibson, G.; Kirtley, J. R.; Ketchen, M. B.; Moler, K. A.

    We demonstrate a time-resolved scanning Superconducting QUantum Interference Device (SQUID) sensor with an expected maximum sampling rate of 50 GHz. The time-resolved SQUID sampler is operated by a pump-probe pulse sequence and will be particularly useful in studying high-frequency magnetic devices and the transient behavior of magnetic materials. The high sampling rate is achieved through a Josephson-interferometry technique developed at IBM. We tested our sampler with flux signals of order 10 mΦ0 (where Φ0 is the magnetic flux quantum), which corresponds to 25 million Bohr magnetons located 1 micron directly below the pickup loop. Operating in this regime, our sampler will have much higher sensitivity than bulk sensors like conventional SQUIDs and much larger spatial scanning range than single-spin sensors like NV centers. The SQUID sampler will thus be well-suited to characterize individual mesoscopic samples as well as bulk samples with mesoscopic features.

  7. Enhanced Dynamic Range in N-SQUID Lumped Josephson Parametric Amplifiers

    NASA Astrophysics Data System (ADS)

    Eddins, A.; Levenson-Falk, E. M.; Toyli, D. M.; Vijay, R.; Minev, Z.; Siddiqi, I.

    2014-03-01

    Simultaneously providing high gain and nearly quantum-limited noise performance, superconducting parametric amplifiers (paramps) have been used successfully for high fidelity qubit readout, quantum feedback, and microwave quantum optics experiments. The Lumped Josephson Parametric Amplifier (LJPA) consists of a capacitively shunted SQUID coupled to a transmission line to form a nonlinear resonator. Like other paramps employing a resonant circuit, the LJPA's dynamic range-a potentially key ingredient for multiplexing-is limited. Simple theory predicts that the dynamic range can be increased without any reduction in bandwidth or gain by distributing the resonator nonlinearity over a series array of SQUIDs. We fabricated such array devices with up to 5 SQUIDs and observed a clear increase in the critical power for bifurcation about which parametric gain occurs. We discuss in detail amplifier performance as a function of the number of SQUIDs in the array. This research was supported by the Army Research Office under a QCT grant.

  8. Multichannel SQUID system detecting tangential components of the cardiac magnetic field

    NASA Astrophysics Data System (ADS)

    Tsukada, Keiji; Haruta, Yasuhiro; Adachi, Akira; Ogata, Hisanao; Komuro, Takanori; Ito, Tsuyoshi; Takada, Youichi; Kandori, Akihiko; Noda, Yasunaga; Terada, Yasushi; Mitsui, Toshio

    1995-10-01

    The 32-channel SQUID system described here is used for diagnosing heart disease by measuring the x and y components of the cardiac magnetic field. To detect a magnetic field parallel to the body surface, it uses a compact hybrid superconducting quantum interference device (SQUID) gradiometer consisting of a planar pickup coil (fabricated using thin-film techniques) and a square double-washer dc-SQUID having large voltage-flux transfer function. The SQUIDs are operated in a flux-locked mode using simple readout circuits connected directly to the preamplifier without additional positive feedback. The system is installed in a magnetically shielded room in a hospital. A low noise characteristics lower than 10 ft/√ Hz in a white noise is obtained in the hospital. Examples of tangential magnetocardiogram (MCG) measurements presented here show that the MCG obtained using this gradiometer makes it easy to visually estimate the electrophysiological behavior of the heart.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  10. SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

    SciTech Connect

    Moessle, Michael; Hatridge, Michael; Clarke, John

    2006-08-14

    in MRI using laser polarized noble gases such as {sup 3}He or {sup 129}Xe (10-12). Hyperpolarized gases were used successfully to image the human lung in fields on the order of several mT (13-15). To overcome the sensitivity loss of Faraday detection at low frequencies, ultrasensitive magnetometers based on the Superconducting QUantum Interference Device (SQUID) (16) are used to detect NMR and MRI signals (17-24). Recently, SQUID-based MRI systems capable of acquiring in vivo images have appeared. For example, in the 10-mT system of Seton et al. (18) signals are coupled to a SQUID via a superconducting tuned circuit, while Clarke and coworkers (22, 25, 26) developed a system at 132 {micro}T with an untuned input circuit coupled to a SQUID. In a quite different approach, atomic magnetometers have been used recently to detect the magnetization (27) and NMR signal (28) of hyperpolarized gases. This technique could potentially be used for low-field MRI in the future. The goal of this review is to summarize the current state-of-the-art of MRI in microtesla fields detected with SQUIDs. The principles of SQUIDs and NMR are briefly reviewed. We show that very narrow NMR linewidths can be achieved in low magnetic fields that are quite inhomogeneous, with illustrative examples from spectroscopy. After describing our ultralow-field MRI system, we present a variety of images. We demonstrate that in microtesla fields the longitudinal relaxation T{sub 1} is much more material dependent than is the case in high fields; this results in a substantial improvement in 'T{sub 1}-weighted contrast imaging'. After outlining the first attempts to combine microtesla NMR with magnetoencephalography (MEG) (29), we conclude with a discussion of future directions.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1999-11-01

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

  14. Detection of Fatigue Damage Prior to Crack Initiation withScanning SQUID Microscopy

    SciTech Connect

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

    2005-11-07

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  16. 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.

  17. Why flies are good vectors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It was around 1900 when house flies were implicated in disease transmission. Flies with white powder on their feet were seen landing on food in US Army chow halls. This white powder was lime that had been sprinkled over the human excrement in open latrines not too far from the eating establishments....

  18. 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 ...

  19. 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.

  20. 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

  1. A HTS dc SQUID-NMR: fabrication of the SQUID and application to low-field NMR for fruit quality detection

    NASA Astrophysics Data System (ADS)

    Isingizwe Nturambirwe, J. Frédéric; Perold, Willem J.; Opara, Linus U.

    2014-06-01

    Superconducting Quantum Interference Devices (SQUIDs) have made the detection of low-field (LF) and ultra-low field nuclear magnetic resonance (ULF-NMR) a reality. The latter has been proven to be a potential tool for non-destructive quality testing of horticultural products, amongst many other applications. High-Temperature Superconductor (HTS) dc SQUIDS are likely to allow for the development of not only low-cost NMR systems but also prototypes that are mobile and easily maintainable. A HTS dc SQUID was manufactured on an YBCO thin film, using a novel laser based lithography method. The lithography was implemented by a new laser system developed in-house, as a model of low-cost lithography systems. The junctions of the dc SQUID were tested and displayed normal I-V characteristics in the acceptable range for the application. In order to determine the viability of low-field NMR for non-destructive quality measurement of horticultural products, a commercial HTS dc SQUID-NMR system was used to measure quality parameters of banana during ripening. The trend of color change and sugar increase of the banana during ripening were the most highly correlated attributes to the SQUID-NMR measured parameter, average T1 (spin-lattice relaxation time). Further studies were done, that involved processing of the NMR signal into relaxation time resolved spectra. A spectral signature of banana was obtained, where each peak is a T1 value corresponding to a proton pool, and is reported here. These results will potentially lead to deeper understanding of the quality of the samples under study.

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

    PubMed

    Guerrero-Ferreira, R C; Nishiguchi, M K

    2007-10-01

    Luminescent bacteria in the family Vibrionaceae (Bacteria: γ-Proteobacteria) are commonly found in complex, bilobed light organs of sepiolid and loliginid squids. Although morphology of these organs in both families of squid is similar, the species of bacteria that inhabit each host has yet to be verified. We utilized sequences of 16S ribosomal RNA, luciferase α-subunit (luxA) and the glyceraldehyde-3-phosphate dehydrogenase (gapA) genes to determine phylogenetic relationships between 63 strains of Vibrio bacteria, which included representatives from different environments as well as unidentified luminescent isolates from loliginid and sepiolid squid from Thailand. A combined phylogenetic analysis was used including biochemical data such as carbon use, growth and luminescence. Results demonstrated that certain symbiotic Thai isolates found in the same geographic area were included in a clade containing bacterial species phenotypically suitable to colonize light organs. Moreover, multiple strains isolated from a single squid host were identified as more than one bacteria species in our phylogeny. This research presents evidence of species of luminescent bacteria that have not been previously described as symbiotic strains colonizing light organs of Indo-West Pacific loliginid and sepiolid squids, and supports the hypothesis of a non-species-specific association between certain sepiolid and loliginid squids and marine luminescent bacteria. PMID:22707847

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

    SciTech Connect

    Kleiner, Reinhold; Koelle, Dieter; Clarke, John

    2007-01-15

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

  4. 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

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

    PubMed

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

    2016-02-01

    Squids are distributed worldwide, including many species of commercial importance, and they are often made into varieties of flavor foods. The rapid identification methods for squid species especially their processed products, however, have not been well developed. In this study, quantitative real-time PCR (qPCR) systems based on specific primers and TaqMan probes have been established for rapid and accurate identification of four common squid species (Ommastrephes bartramii, Dosidicus gigas, Illex argentinus, Todarodes pacificus) in Chinese domestic market. After analyzing mitochondrial genes reported in GenBank, the mitochondrial cytochrome b (Cytb) gene was selected for O. bartramii detection, cytochrome c oxidase subunit I (COI) gene for D. gigas and T. Pacificus detection, ATPase subunit 6 (ATPase 6) gene for I. Argentinus detection, and 12S ribosomal RNA (12S rDNA) gene for designing Ommastrephidae-specific primers and probe. As a result, all the TaqMan systems are of good performance, and efficiency of each reaction was calculated by making standard curves. This method could detect target species either in single or mixed squid specimen, and it was applied to identify 12 squid processed products successfully. Thus, it would play an important role in fulfilling labeling regulations and squid fishery control. PMID:26772407

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

    SciTech Connect

    Wikswo, J.P. Jr.

    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.

  7. Magnetic Nanoparticle Characterization Using Nano-SQUID based on Niobium Dayem Bridges

    NASA Astrophysics Data System (ADS)

    Russo, R.; Esposito, E.; Granata, C.; Vettoliere, A.; Russo, M.; Cannas, C.; Peddis, D.; Fiorani, D.

    Magnetic nano-sensors based on niobium dc SQUID (Superconducting Quantum Interference Device) for nanoparticle characterization are presented. The SQUIDs consists of two Dayem bridges of 90 nm x 250 nm and loop area of 4, 1 and 0.55 μm2. The SQUIDs were designed to have a hysteretic current-voltage characteristic in order to work as a magnetic flux-current transducer. Current-voltage characteristics, critical current as a function of the external magnetic field and switching current distributions were performed at liquid helium temperature. A critical current modulation of about 20% and a current-magnetic flux transfer coefficient (responsivity) of 30 μA/Φ0 have been obtained, resulting in a magnetic flux resolution better than 1 mΦ0. In order to show the effectiveness of sensor for nanomagnetism applications, we performed measurements with and without magnetic nanoparticles on the SQUID loop applying a magnetic field parallel to the SQUID plane. In this configuration the magnetic flux coupled to the SQUID is mainly due to the presence of magnetic nanoparticles. The magnetic nanoparticles can be easily detected and their response to magnetic field studied. Measurements has been performed on Fe3O4 nanoparticles prepared by thermal decomposition method with a nominal particle size of 8 nm. Some examples of magnetization measurements were recorded at low temperature after Zero Field Cooling.

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

    NASA Astrophysics Data System (ADS)

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

    2002-05-01

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

  9. Single SQUID multiplexer for arrays of voltage-biased superconducting bolometers

    SciTech Connect

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

    2001-08-20

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

  10. Opportunities and Challenges for Education and Outreach at NEON (National Ecological Observatory Network), a new NSF Large Facility

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    As a new NSF Large Facility, NEON (the National Ecological Observatory Network) collects continental-scale ecological and environmental data to support research and education on large-scale ecological processes. The Observatory provides data, infrastructure and educational resources to scientific, educational and general public audiences. We designed NEON's Education and Outreach (E & O) activities to meet several high-level goals, including (1) facilitating public understanding of ecological science, (2) providing tools to use NEON data, (3) educating the next generation of ecologists, and (4) enhancing diversity within the ecological community. The suite of activities we developed ranges from online resources for using NEON data to a Citizen Science project to traditional undergraduate internship programs and workshops for graduate students/early career scientists. The NEON Construction Project represents one of the first large facilities that included E & O activities as set of deliverables with defined requirements in parallel to other components of construction. This approach proved to be both an opportunity to build a multifaceted E & O program in collaboration with NEON science and engineering, and a challenge as competing priorities sometimes left E & O resource development teams without necessary technical expertise. The result, however, is a robust suite of online educational resources, citizen science opportunities, and in-person training programs. Early evaluation efforts have helped us fine tune our programming to meet the needs of target audiences, including diverse undergraduate students, graduate students, scientists, faculty, edcuators, and citizen scientists. Moving into Operations, we envision an evolving suite of resources and programs that further NEON's mission and engage audiences in "doing science," both by using NEON data in a diversity of contexts and participating in our citizen science opportunities.

  11. Atlas of the Spectrum of a Platinum/Neon Hollow-Cathode Lamp in the Region 1130-4330 Å

    National Institute of Standards and Technology Data Gateway

    SRD 112 Atlas of the Spectrum of a Platinum/Neon Hollow-Cathode Lamp in the Region 1130-4330 Å (Web, free access)   Atlas of the Spectrum of a Platinum/Neon Hollow-Cathode Lamp in the Region 1130-4330 Å contains wavelengths and intensities for about 5600 lines in the region 4330 Å. An atlas plot of the spectrum is given, with the spectral lines marked and their intensities, wavelengths, and classifications listed.

  12. Development of Magnetization Measurement Devices Using Micro-dc-SQUIDs and a Sr_2RuO_4 Microplate

    NASA Astrophysics Data System (ADS)

    Nago, Y.; Shinozaki, T.; Tsuchiya, S.; Ishiguro, R.; Kashiwaya, H.; Kashiwaya, S.; Nomura, S.; Kono, K.; Takayanagi, H.; Maeno, Y.

    2016-05-01

    We developed high-sensitivity magnetization measurement devices composed of micro-dc-SQUIDs and a superconducting Sr_2RuO_4 microplate, aiming to investigate novel magnetic properties related to a spin-triplet chiral p-wave superconductor with a mesoscopic size. Micron-sized dc-SQUID was fabricated by thin Al electrodes, and the SQUID structure was improved to prevent magnetic fluxes from intruding into SQUID electrodes. A Sr_2RuO_4 superconducting microplate was fabricated into the size as small as the SQUID loop using a focused ion beam and directly mounted on the SQUID with precise positioning for high-sensitivity magnetization measurements. In the preliminary magnetization measurements of this device, we observed vortices trapped into the plate and thus the lower critical field. The improved magnetization measurement device developed to exclude undesirable flux intrusion successfully enabled high-sensitivity detection of quantized vortex.

  13. The flying radiation case

    SciTech Connect

    Brownell, J.H.; Bowers, R.L.

    1997-04-01

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

  14. Evidence of strong projectile-target-core interaction in single ionization of neon by electron impact

    SciTech Connect

    Yan, S.; Zhang, P.; Xu, S.; Ma, X.; Zhang, S. F.; Zhu, X. L.; Feng, W. T.; Liu, H. P.

    2010-11-15

    The momentum distributions of recoil ions were measured in the single ionization of neon by electron impact at incident energies between 80 and 2300 eV. It was found that there are a noticeable number of recoil ions carrying large momenta, and the relative contributions of these ions becomes more pronounced with the further decrease of incident electron energy. These observed behaviors indicate that there is a strong projectile-target-core interaction in the single-ionization reaction. By comparing our results with those of electron-neon elastic scattering, we concluded that the elastic scattering of the projectile electron on the target core plays an important role at low and intermediate collision energies.

  15. The infrared spectrum of NN···CO+ trapped in solid neon.

    PubMed

    Thompson, Warren E; Jacox, Marilyn E

    2011-12-14

    Codeposition of a Ne:N(2):CO = 200:1:1 mixture at 4.3 K with a beam of very pure neon atoms excited to their energy levels between 16.6 and 16.85 eV leads to stabilization in the resulting solid of sufficient NNCO(+) for detection of its NN- and CO-stretching vibration fundamentals. Detailed isotopic substitution studies and density functional calculations for the various isotopologues support the identification of NNCO(+) and permit estimation of the positions of two of its low-frequency fundamentals. A sufficient concentration of NOCN is also stabilized in the neon matrix for detection of its NO-stretching vibrational fundamental. PMID:22168694

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

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

    PubMed

    Wiebke, Jonas; Pahl, Elke; Schwerdtfeger, Peter

    2012-07-01

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

  18. Electronic absorption spectra of protonated pyrene and coronene in neon matrixes.

    PubMed

    Garkusha, Iryna; Fulara, Jan; Sarre, Peter J; Maier, John P

    2011-10-13

    Protonated pyrene and coronene have been isolated in 6 K neon matrixes. The cations were produced in the reaction of the parent aromatics with protonated ethanol in a hot-cathode discharge source, mass selected, and co-deposited with neon. Three electronic transitions of the most stable isomer of protonated pyrene and four of protonated coronene were recorded. The strongest, S(1) ← S(0) transitions, are in the visible region, with onset at 487.5 nm for protonated pyrene and 695.6 nm for protonated coronene. The corresponding neutrals were also observed. The absorptions were assigned on the basis of ab initio coupled-cluster and time-dependent density functional theory calculations. The astrophysical relevance of protonated polycyclic aromatic hydrocarbons is discussed. PMID:21861507

  19. Crystal structure and encapsulation dynamics of ice II-structured neon hydrate.

    PubMed

    Yu, Xiaohui; Zhu, Jinlong; Du, Shiyu; Xu, Hongwu; Vogel, Sven C; Han, Jiantao; Germann, Timothy C; Zhang, Jianzhong; Jin, Changqing; Francisco, Joseph S; Zhao, Yusheng

    2014-07-22

    Neon hydrate was synthesized and studied by in situ neutron diffraction at 480 MPa and temperatures ranging from 260 to 70 K. For the first time to our knowledge, we demonstrate that neon atoms can be enclathrated in water molecules to form ice II-structured hydrates. The guest Ne atoms occupy the centers of D2O channels and have substantial freedom of movement owing to the lack of direct bonding between guest molecules and host lattices. Molecular dynamics simulation confirms that the resolved structure where Ne dissolved in ice II is thermodynamically stable at 480 MPa and 260 K. The density distributions indicate that the vibration of Ne atoms is mainly in planes perpendicular to D2O channels, whereas their distributions along the channels are further constrained by interactions between adjacent Ne atoms. PMID:25002464

  20. Crystal structure and encapsulation dynamics of ice II-structured neon hydrate

    PubMed Central

    Yu, Xiaohui; Zhu, Jinlong; Du, Shiyu; Xu, Hongwu; Vogel, Sven C.; Han, Jiantao; Germann, Timothy C.; Zhang, Jianzhong; Jin, Changqing; Francisco, Joseph S.; Zhao, Yusheng

    2014-01-01

    Neon hydrate was synthesized and studied by in situ neutron diffraction at 480 MPa and temperatures ranging from 260 to 70 K. For the first time to our knowledge, we demonstrate that neon atoms can be enclathrated in water molecules to form ice II-structured hydrates. The guest Ne atoms occupy the centers of D2O channels and have substantial freedom of movement owing to the lack of direct bonding between guest molecules and host lattices. Molecular dynamics simulation confirms that the resolved structure where Ne dissolved in ice II is thermodynamically stable at 480 MPa and 260 K. The density distributions indicate that the vibration of Ne atoms is mainly in planes perpendicular to D2O channels, whereas their distributions along the channels are further constrained by interactions between adjacent Ne atoms. PMID:25002464

  1. Trapping hydrogen atoms from a neon-gas matrix: a theoretical simulation.

    PubMed

    Bovino, S; Zhang, P; Kharchenko, V; Dalgarno, A

    2009-08-01

    Hydrogen is of critical importance in atomic and molecular physics and the development of a simple and efficient technique for trapping cold and ultracold hydrogen atoms would be a significant advance. In this study we simulate a recently proposed trap-loading mechanism for trapping hydrogen atoms released from a neon matrix. Accurate ab initio quantum calculations are reported of the neon-hydrogen interaction potential and the energy- and angular-dependent elastic scattering cross sections that control the energy transfer of initially cold atoms are obtained. They are then used to construct the Boltzmann kinetic equation, describing the energy relaxation process. Numerical solutions of the Boltzmann equation predict the time evolution of the hydrogen energy distribution function. Based on the simulations we discuss the prospects of the technique. PMID:19673557

  2. 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.

  3. The isotopic and elemental abundances of neon nuclei accelerated in solar flares

    NASA Technical Reports Server (NTRS)

    Dietrich, W. F.; Simpson, J. A.

    1979-01-01

    The relative isotopic abundances of Ne-20 and Ne-22 in seven solar flares were determined from measurements of the satellite IMP 8, yielding the ratio Ne-20/Ne-22 = 7.7 (+2.3, -1.5) for solar chromospheric matter. This value is in agreement with the ratio for the component neon-A (the 'primordial' component) found in carbonaceous chondrites. An elemental abundance ratio Ne/O = 0.14 + or - 0.01 also has been obtained which agrees closely with earlier reported measurements. It is shown that the effects of preferential acceleration relative to solar-system abundances with increasing charge number observed for some solar flares - though biasing the elemental ratio - does not appear to influence the neon isotopic abundances.

  4. Effects of helio-neon laser radiation upon cellular cycle in a plant model

    SciTech Connect

    de Barioglio, S.R.; Fiol de Cuneo, M.; Lacuara, J.L.; Juri, H.

    1989-01-01

    The scope of this study was to investigate possible relationships between He-Neon laser radiation and mitotic and phase indices in meristematic cells of Allium cepa L. bulbs. Our results indicate that mitotic index increased after irradiation depending this modification on the time exposure and the potency of the He-Neon beam. Phase indices were also modified: frequency of prophase increased, while inter- meta- and anaphase decreased: telophases remain unchanged. These variations were significative only when the preparations were irradiated (a) with 5 mW for 10 min. or more, (b) with 10 mW or (c) when the preparations were processed 60 min. after irradiation. These findings could not be attributed to thermal changes. Modifications in RNA or protein synthesis could be responsible.

  5. 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.

  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.

    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. 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.

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

    NASA Astrophysics Data System (ADS)

    Wasser, L. A.

    2015-12-01

    "Big Data" are becoming increasingly common in many fields. The National Ecological Observatory Network (NEON) will collect 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, working with big data is challenging. New and potentially unfamiliar data types and associated processing methods, required to work with a growing diversity of available data take time and resources to learn. 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, resources that support learning these concepts and approaches, are distributed widely across multiple online spaces and may take time to find. This presentation will overview the development of NEON's collaborative University-focused online education portal. It will also cover content testing, community feedback and results from workshops using online content. Portal content is hosted in github to facilitate community input, accessibility version control. Content includes 1) videos and supporting graphics that explain key concepts related to NEON and related big spatio-temporal and 2) data tutorials that include subsets of spatio-temporal data that can be used to learn key big data skills in a self-paced approach, or that can be used as a teaching tool in the classroom or in a workshop. All resources utilize free and open data processing, visualization and analysis tools, techniques and scripts. All NEON materials are being developed in collaboration with the scientific community and are being tested via in-person workshops. Visit the portal online: www.neondataskills.org.

  10. Differential cross sections for ionization of helium, neon, and argon by fast electrons

    SciTech Connect

    Miller, J.H.; Manson, S.T.

    1984-05-01

    Ionization cross sections, differential in the energy of secondary electrons, are presented for high-energy electrons incident on helium, neon, and argon. The results are based on Bethe's theory for inelastic scattering of fast charged particles using photoabsorption data and proton-impact differential ionization cross sections to determine the coefficients of this asymptotic expansion of the first Born approximation. The model cross sections are compared with experimental data for primary-electron energies between 100 and 5000 eV.

  11. Energy levels in helium and neon atoms by an electron-impact method

    NASA Astrophysics Data System (ADS)

    Taylor, N.; Bartle, K. D.; Mills, D.; Beard, D. S.

    1981-03-01

    Electronic energy levels in noble gas atoms may be determined with a simple teaching apparatus incorporating a resonance potentials tube in which the electron beam intensity is held constant. The resulting spectra are little inferior to those obtained by more elaborate electron-impact methods and complement optical emission spectra. Singlet-triplet energy differences may be resolved, and the spectra of helium and neon may be used to illustrate the applicability of Russell-Saunders and other, ''intermediate,'' coupling schemes.

  12. Sorptivity of fly ash concretes

    SciTech Connect

    Gopalan, M.K.

    1996-08-01

    A factorial experiment was designed to measure the sorptivity of cement and fly ash concretes in order to compare the durability of fly ash concrete against the cement concrete. Sorptivity measurements based on the capillary movement of water was made on three grades of cement concrete and six grades of fly ash mixes. The effect of curing was also studied by treating the samples in two curving conditions. A functional relationship of sorptivity against the strength, curing condition and fly ash content has been presented. The results were useful to analyze the factors influencing the durability of cement and fly ash concretes and to explain why some of the previously reported findings were contradictory. Curing conditions have been found to be the most important factor that affected the durability properties of fly ash concrete. When proper curing was provided, a mix with 40% fly ash was found to reduce the sorptivity by 37%. Under inadequate curing the sorptivity was found to increase by 60%. The influence of curing on cement concrete was found to be of much less importance.

  13. Potential enhanced ability of giant squid to detect sperm whales is an exaptation tied to their large body size.

    PubMed

    Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Wainwright, Peter C

    2013-01-01

    It has been hypothesized that sperm whale predation is the driver of eye size evolution in giant squid. Given that the eyes of giant squid have the size expected for a squid this big, it is likely that any enhanced ability of giant squid to detect whales is an exaptation tied to their body size. Future studies should target the mechanism behind the evolution of large body size, not eye size. Reconstructions of the evolutionary history of selective regime, eye size, optical performance, and body size will improve the understanding of the evolution of large eyes in large ocean animals. PMID:24127991

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

    PubMed

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

    2008-03-01

    This study presents the first target strength measurements of Dosidicus gigas, a large squid that is a key predator, a significant prey, and the target of an important fishery. Target strength of live, tethered squid was related to mantle length with values standardized to the length squared of -62.0, -67.4, -67.9, and -67.6 dB at 38, 70, 120, and 200 kHz, respectively. There were relatively small differences in target strength between dorsal and anterior aspects and none between live and freshly dead squid. Potential scattering mechanisms in squid have been long debated. Here, the reproductive organs had little effect on squid target strength. These data support the hypothesis that the pen may be an important source of squid acoustic scattering. The beak, eyes, and arms, probably via the sucker rings, also play a role in acoustic scattering though their effects were small and frequency specific. An unexpected source of scattering was the cranium of the squid which provided a target strength nearly as high as that of the entire squid though the mechanism remains unclear. Our in situ measurements of the target strength of free-swimming squid support the use of the values presented here in D. gigas assessment studies. PMID:18345820

  15. Characterization of large two-dimensional YBa2Cu3O7–δ SQUID arrays

    NASA Astrophysics Data System (ADS)

    Taylor, B. J.; Berggren, S. A. E.; O’Brien, M. C.; deAndrade, M. C.; Higa, B. A.; Leese de Escobar, A. M.

    2016-08-01

    Large two-dimensional SQUID arrays were made using the step-edge Josephson junction process. The performance of the arrays is analyzed with respect to determining the conditions under which the optimal performance is achieved. We find that optimization of the field-voltage transfer function V B is reached at a specific temperature and device current bias point, and arrive at an empirical expression describing the dependence of V B on the critical current and dynamic resistance of the SQUID array and as a function of temperature. The empirical expression for V B of the SQUID arrays is similar to that given by well known theoretical models for a single SQUID.

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

    SciTech Connect

    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 {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.

  18. 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.

  19. Helium-neon laser improves bone repair in rabbits: comparison at two anatomic sites.

    PubMed

    Peccin, Maria Stella; de Oliveira, Flavia; Muniz Renno, Ana Claudia; Pacheco de Jesus, Gustavo Protasio; Pozzi, Renan; Gomes de Moura, Carolina Foot; Giusti, Paulo Ricardo; Ribeiro, Daniel Araki

    2013-07-01

    The purpose of this study was to evaluate the influence of helium-neon laser on bone repair of femur and tibia in rabbits. For this purpose, 15 New Zealand rabbits underwent bilateral bone damage (tibia and femur) using a spherical bur. Helium-neon laser light, at a fluency of 6 J∕cm(2) and wavelength of 632.8 nm was applied on the left legs (laser group). The right tibia or femur lesions (control group) served as negative control. All sections were histopathologically analyzed using HE sections and the morphometric data from bone tissue and hyaline cartilage were achieved. Histopathological analysis showed regular bone trabeculae covered by osteoblastic cells after 1 week in the group exposed to laser therapy from femur and tibia indistinctly. After 3 weeks, the laser group showed new bone formation coming from the bony walls in the femur and tibia as well. On the 5th week, well-defined trabecula undergoing remodeling process was detected for the most intense pattern in tibia only. Morphometric analysis revealed significant statistical differences (p < 0.05) in the bone tissue for the laser-exposed group on 1st and 3rd weeks. After 5th week, bone formation was increased to tibia only. Taken together, such findings suggest that helium-neon laser is able to improve bone repair in rabbits being the most pronounced effect in tibia. PMID:23053246

  20. On the stability of cationic complexes of neon with helium--solving an experimental discrepancy.

    PubMed

    Bartl, Peter; Denifl, Stephan; Scheier, Paul; Echt, Olof

    2013-10-21

    Helium nanodroplets are doped with neon and ionized by electrons. The size-dependence of the ion abundance of HenNex(+), identified in high-resolution mass spectra, is deduced for complexes containing up to seven neon atoms and dozens of helium atoms. Particularly stable ions are inferred from anomalies in the abundance distributions. Two pronounced anomalies at n = 11 and 13 in the HenNe(+) series confirm drift-tube data reported by Kojima et al. [T. M. Kojima et al., Z. Phys. D, 1992, 22, 645]. The discrepancy with previously published spectra of neon-doped helium droplets, which did not reveal any abundance anomalies [T. Ruchti et al., J. Chem. Phys., 1998, 109, 10679-10687; C. A. Brindle et al., J. Chem. Phys., 2005, 123, 064312], is most likely due to limited mass resolution, which precluded unambiguous analysis of contributions from different ions with identical nominal mass. However, calculated dissociation energies of HenNe(+) reported so far do not correlate with the present data, possibly because of challenges in correctly treating the linear, asymmetric [He-Ne-He](+) ionic core in HenNe(+). Anomalies identified in the distributions of HenNex(+) for x > 1, including prominent ones at He12Ne2(+) and He14Ne2(+), may help to better understand solvation of Ne(+) and Nex(+) in helium. PMID:23958826