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Sample records for humboldt squid dosidicus

  1. Trophic relationships between the jumbo squid (Dosidicus gigas and the lightfish (Vinciguerria lucetia in the Humboldt Current System off Peru

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    Rigoberto Rosas-Luis

    2011-04-01

    Full Text Available Acoustic surveys for assessing the biomass and distribution of the jumbo squid (Dosidicus gigas and the lightfish (Vinciguerria lucetia were carried out in the Humboldt Current System of Peru in 2007 and 2008. At the same time, 937 jumbo squid were caught and their stomach contents analyzed. The diet of the jumbo squid was dominated by mesopelagic fish. The first component of their fish diet was V. lucetia and the second component was the myctophid fish Diogenichthys laternatus. Acoustic biomass estimates of these species show that V. lucetia is an important component in aggregative structures in the Humboldt Current System of Peru and its distribution and movements are closely related to the migratory movements of the jumbo squid. The trophic relationship observed between D. gigas and V. lucetia promotes an increase in jumbo squid biomass and, has a positive trophic effect on the ocean ecosystem.

  2. Age, maturation, and population structure of the Humboldt squid Dosidicus gigas off the Peruvian Exclusive Economic Zones

    Institute of Scientific and Technical Information of China (English)

    LIU Bilin; CHEN Xinjun; CHEN Yong; TIAN Siquan; LI Jianhua; FANG Zhou; YANG Mingxia

    2013-01-01

    Age,maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones (EEZ) during 2008-2010.Estimated ages ranged from 144 to 633 days,confirming that the squid is a short-lived species with longevity no longer than 2 years.Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round.Back-calculated hatching dates for the samples were from January 22nd,2008 to April 22nd,2010 with a peak between January and March.Two size-based and two hatching date-based populations could be defined from mantle length (ML) at maturity and back-calculated hatching dates,respectively.Females matured at a larger size than males,and there was a significant difference in ML at maturity between the two hatching groups (P<0.05).The waters adjacent to 11°S off the Peruvian EEZ may be a potential spawning ground.This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ,which should be considered in the assessment and management of this important resource.

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

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    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.

  4. The biology and ecology of the jumbo squid Dosidicus gigas (Cephalopoda in Chilean waters: a review

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    Christian M Ibáñez

    2015-07-01

    Full Text Available ABSTRACT. The jumbo squid Dosidicus gigas is the most abundant cephalopod species in the southeastern Pacific Ocean, which supports the biggest cephalopod fishery in the world. Due to its growing economic importance, the population growth and distributional expansion of this squid is being increasingly studied. Nevertheless, some basic features of the biology of D. gigas are still unknown or have been poorly investigated. In this review we summarize the known information regarding the biology and ecology of this species in the southeastern Pacific Ocean; we focus on the Chilean region in order to propose hypotheses and research lines for a better understanding the life history of this organism. Available data on the size structure, reproduction and genetics of D. gigas allows us to propose hypotheses related to the squid's life history traits. Based on the current literature and publications of colleagues, we propose two hypotheses regarding the effect of spatial variation on the life history of D. gigas. Hypothesis 1: Squids mature at large sizes and spawn in oceanic waters with warm temperatures where paralarvae and juveniles develop. Immature squids migrate near shore to feed, grow and mature, and then return to the offshore sites to spawn. Hypothesis 2: Alternatively, juvenile D. gigas in the oceanic zone do not migrate to coastal waters and mature at small sizes compared to individuals living near the coast that mature at larger size and migrate to oceanic waters to spawn. We provide background information about the feeding behavior and parasitism of this species, suggesting that D. gigas is an important trophic link in the southeastern Pacific marine ecosystem. However, more studies on the feeding habits, reproduction and parasite load are needed not only to test hypotheses proposed in this study, but also to advance the overall knowledge of this species.

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

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    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.

  6. A Comparative Study of Spatially Clustered Distribution of Jumbo Flying Squid (Dosidicus gigas) Offshore Peru

    Institute of Scientific and Technical Information of China (English)

    FENG Yongjiu; CUI Li; CHEN Xinjun; LIU Yu

    2017-01-01

    We examined spatially clustered distribution of jumbo flying squid (Dosidicus gigas) in the offshore waters of Peru bounded by 78°-86°W and 8°-20°S under 0.5°×0.5° fishing grid.The study is based on the catch-per-unit-effort (CPUE) and fishing effort from Chinese mainland squid jigging fleet in 2003-2004 and 2006-2013.The data for all years as well as the eight years (excluding E1 Ni(n)o events) were studied to examine the effect of climate variation on the spatial distribution of D.gigas.Five spatial clusters reflecting the spatial distribution were computed using K-means and Getis-Ord Gi* for a detailed comparative study.Our results showed that clusters identified by the two methods were quite different in terms of their spatial patterns,and K-means was not as accurate as Getis-Ord Gi*,as inferred from the agreement degree and receiver operating characteristic.There were more areas of hot and cold spots in years without the impact of El Ni(n)o,suggesting that such large-scale climate variations could reduce the clustering level ofD.gigas.The catches also showed that warm E1 Ni(n)o conditions and high water temperature were less favorable for D.gigas offshore Peru.The results suggested that the use of K-means is preferable if the aim is to discover the spatial distribution of each sub-region (cluster) of the study area,while Getis-Ord Gi* is preferable if the aim is to identify statistically significant hot spots that may indicate the central fishing ground.

  7. A comparative study of spatially clustered distribution of jumbo flying squid ( Dosidicus gigas) offshore Peru

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    Feng, Yongjiu; Cui, Li; Chen, Xinjun; Liu, Yu

    2017-06-01

    We examined spatially clustered distribution of jumbo flying squid ( Dosidicus gigas) in the offshore waters of Peru bounded by 78°-86°W and 8°-20°S under 0.5°×0.5° fishing grid. The study is based on the catch-per-unit-effort (CPUE) and fishing effort from Chinese mainland squid jigging fleet in 2003-2004 and 2006-2013. The data for all years as well as the eight years (excluding El Niño events) were studied to examine the effect of climate variation on the spatial distribution of D. gigas. Five spatial clusters reflecting the spatial distribution were computed using K-means and Getis-Ord Gi* for a detailed comparative study. Our results showed that clusters identified by the two methods were quite different in terms of their spatial patterns, and K-means was not as accurate as Getis-Ord Gi*, as inferred from the agreement degree and receiver operating characteristic. There were more areas of hot and cold spots in years without the impact of El Niño, suggesting that such large-scale climate variations could reduce the clustering level of D. gigas. The catches also showed that warm El Niño conditions and high water temperature were less favorable for D. gigas offshore Peru. The results suggested that the use of K-means is preferable if the aim is to discover the spatial distribution of each sub-region (cluster) of the study area, while Getis-Ord Gi* is preferable if the aim is to identify statistically significant hot spots that may indicate the central fishing ground.

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

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

    2018-04-15

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

  9. Description of plastic remains found in the stomach contents of the jumbo squid Dosidicus gigas landed in Ecuador during 2014.

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    Rosas-Luis, Rigoberto

    2016-12-15

    Squids are active and opportunistic predators that feed on a wide range of prey. Their active movements in the water column and their voracity promote a high consumption of food. In the pelagic environment off Ecuador, marine pollution is characterized by plastic debris with a mainland origin, including plastics trash of fishing gears. The objective of this work was to describe the presence of plastic remains in the stomach contents of Dosidicus gigas caught off the coast of Ecuador. Results demonstrated that 12% of the stomachs contained plastic remains. These plastics were identified as multifilament of polyethylene lines and polyvinyl chloride remains. Findings of this work could be related to an increase in the discharge of solid materials in the water column, increasing the probability to be ingested by the jumbo squid. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Effect of Bovine Plasma Protein on Autolysis and Gelation of Protein Extracted from Giant Squid (Dosidicus gigas Mantle

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    Laura Raquel Marquez-Alvarez

    2015-01-01

    Full Text Available The effect of bovine plasma protein (BPP on the inhibition of autolytic activity and its effect on the gelling properties of a protein concentrate (PC obtained from jumbo squid (Dosidicus gigas mantle were investigated. Sols and gels were prepared from the PC by adding different amounts of BPP (0, 1, and 2%. Dynamic oscillatory measurements indicated that systems with 1% BPP had a higher elastic modulus (G′, in which hydrophobic interactions were favored. Concerning the technological and textural quality of the gels, BPP caused a greater water holding capacity (WHC, force, cohesiveness, and elasticity, probably due to improvement of the electrostatic and hydrophobic interactions during gel formation. Scanning electron microscopy (SEM allowed visualization of the formation of more rigid and ordered gels with less porosity when BPP was added. Therefore, the addition of BPP improved the gelling capacity of proteins extracted from giant squid.

  11. Fishery biology of the jumbo flying squid Dosidicus gigas off the Exclusive Economic Zone of Chilean waters

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    Bilin Liu

    2010-11-01

    Full Text Available The jumbo flying squid Dosidicus gigas is widely distributed in the eastern Pacific Ocean and supports an important fishery. Although many studies have been carried out on the biology of this species, limited biological information is available in the waters outside the Exclusive Economic Zone of Chile (EEZ (20°S-41°S and 74°30’W-84°W. Three surveys were conducted in this area by the Chinese squid jigging vessels during the period from April 2006 to May 2008. The majority of the catch in the survey was from the two areas defined by 37°30’-41°S and 78°30’-80°W and by 25°-30°S and 76°-77°30’W. The sex ratio (M: F of the catch was 1: 2.48. The mean mantle length (ML was 376 mm for males with a range of 257-721 mm and 388.7 mm for females with a range of 236-837 mm. Two distinguished size classes, medium- and large-sized groups, were identified in this study with the medium-sized group (350-450 mm ML consisting of 89% of the total catch. The sizes at first sexual maturity were 638 mm ML for females and 565 mm ML for males. This study suggests that all the individuals examined were hatched from March 2007 to February 2008, indicating that D. gigas might spawn all year around with a peak spawning time from November 2007 to January 2008. Most of the stomachs analyzed had food remains. The preys included three major groups: fish (mainly lanternfish, cephalopods and crustaceans, but D. gigas was the dominant species in the stomach contents, showing strong evidence of cannibalism. The information obtained from this study improves our understanding of the fishery biology of D. gigas off Chile.

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

    Institute of Scientific and Technical Information of China (English)

    LIU Bilin; CHEN Xinjun; YI Qian

    2013-01-01

    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.

  13. Spatial and trophic preferences of jumbo squid Dosidicus gigas (D´Orbigny, 1835) in the central Gulf of California: ecological inferences using stable isotopes.

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    Trasviña-Carrillo, L D; Hernández-Herrera, A; Torres-Rojas, Y E; Galván-Magaña, F; Sánchez-González, A; Aguíñiga-García, S

    2018-04-26

    The jumbo squid Dosidicus gigas is a fishery resource of considerable economic and ecological importance in the Mexican Pacific. Studies on its habitat preferences are needed to understand recent fluctuations in the species' abundance and availability. Stable isotope analysis allows us to infer ecological aspects such as spatial distribution and trophic preferences. We used an isotope ratio mass spectrometer, automated for carbonate analysis, and coupled to an elemental analyzer, to determine the isotopic composition of statoliths (δ 18 O and δ 13 C values) and beaks (δ 13 C and δ 15 N values) from 219 individuals caught over two fishing seasons (2007 and 2009) off the coast of Santa Rosalía, in the central Gulf of California. We used these isotopic ratios to assess variation in spatial and trophic preferences by sex, size, and fishing season. In the 2009 group, we observed significant differences in statolith δ 13 C values and beak δ 13 C and δ 15 N values between males and females. Between size groups, we observed significant differences in statolith δ 18 O and δ 13 C values in 2007 and in beak δ 13 C and δ 15 N values during both seasons. Both seasons were characterized by high overlap in δ 18 O and δ 13 C values between sexes and in 2009 between size groups. We observed low trophic overlap between sexes in 2009 and between size groups during both seasons. The isotopic ratios from statoliths and beaks indicate that D. gigas has changed its spatial and trophic preferences, a shift that is probably related to changes in the species diet. This intraspecific variation in preferences could be related to characteristics such as size, which may influence squid distribution preferences. This article is protected by copyright. All rights reserved.

  14. Evaluation of jumbo squid (Dosidicus gigas byproduct hydrolysates obtained by acid-enzymatic hydrolysis and by autohydrolysis in practical diets for Pacific white shrimp (Litopenaeus vannamei

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    Mayra Lizett González-Félix

    2014-09-01

    Full Text Available The marine bioprocessing industry offers great potential to utilize byproducts for fish meal replacement in aquafeeds. Jumbo squid is an important fishery commodity in Mexico, but only the mantle is marketed. Head, fins, guts and tentacles are discarded in spite of being protein-rich byproducts. This study evaluated the use of two jumbo squid byproduct hydrolysates obtained by acid-enzymatic hydrolysis (AEH and by autohydrolysis (AH as ingredients in practical diets for shrimp. The hydrolysates were included at levels of 2.5 and 5.0% of the diet dry weight in four practical diets, including a control diet without hydrolysate. Shrimp growth and survival were not significantly affected by the dietary treatments. Postharvest quality of abdominal muscle was evaluated in terms of proximate composition and sensory evaluation. Significantly higher crude protein was observed in the muscle of shrimp fed the highest hydrolysate levels, AH 5% (204.8 g kg- 1 or AEH 5% (201.3 g kg- 1. Sensory analysis of cooked muscle showed significant differences for all variables evaluated: color, odor, flavor, and firmness. It was concluded that Jumbo squid byproducts can be successfully processed by autohydrolysis or acid-enzymatic hydrolysis, and that up to 5.0% of the hydrolysates can be incorporated into shrimp diets without affecting growth or survival.

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

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

    2013-07-01

    Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1-1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño event in 2009-2010, was accompanied by a collapse of this fishery, and squid in the region showed major changes in the distribution and life-history strategy. Large squid abandoned seasonal coastal-shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Niño by tidal upwelling and a well-mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010 to 2012, small squid were abundant and matured at an unusually small mantle-length (adapt to and cope with El Niño. This ability is likely to be an important factor in conjunction with longerterm climate-change and the potential ecological impacts of this invasive predator on marine ecosystems. © 2013 Blackwell Publishing Ltd.

  16. The role of water on the structure and mechanical properties of a thermoplastic natural block co-polymer from squid sucker ring teeth.

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    Rieu, Clément; Bertinetti, Luca; Schuetz, Roman; Salinas-Zavala, Cesar Ca; Weaver, James C; Fratzl, Peter; Miserez, Ali; Masic, Admir

    2016-09-02

    Hard biological polymers exhibiting a truly thermoplastic behavior that can maintain their structural properties after processing are extremely rare and highly desirable for use in advanced technological applications such as 3D-printing, biodegradable plastics and robust composites. One exception are the thermoplastic proteins that comprise the sucker ring teeth (SRT) of the Humboldt jumbo squid (Dosidicus gigas). In this work, we explore the mechanical properties of reconstituted SRT proteins and demonstrate that the material can be re-shaped by simple processing in water and at relatively low temperature (below 100 °C). The post-processed material maintains a high modulus in the GPa range, both in the dry and the wet states. When transitioning from low to high humidity, the material properties change from brittle to ductile with an increase in plastic deformation, where water acts as a plasticizer. Using synchrotron x-ray scattering tools, we found that water mostly influences nano scale structure, whereas at the molecular level, the protein structure remains largely unaffected. Furthermore, through simultaneous in situ x-ray scattering and mechanical tests, we show that the supramolecular network of the reconstituted SRT material exhibits a progressive alignment along the strain direction, which is attributed to chain alignment of the amorphous domains of SRT proteins. The high modulus in both dry and wet states, combined with their efficient thermal processing characteristics, make the SRT proteins promising substitutes for applications traditionally reserved for petroleum-based thermoplastics.

  17. Traversing Humboldt's transareal landscapes

    DEFF Research Database (Denmark)

    Diedrich, Lisa; Braae, Ellen Marie; Lee, Gini

    2017-01-01

    Die Besonderheit der wissenschaftlichen Arbeit und des Schreibens Alexander von Humboldts wird häufig anhand einer den Raum erschließenden Bewegung beschrieben. Konzepte zur Repräsentation räumlicher Verhältnisse, wie Landschaftsdarstellungen und Karten, sind für Humboldts Vorgehen daher epistemo...... 2016 erschienenen „Horizonte der Humboldt-Forschung: Natur, Kultur, Schreiben“ (POINTE Band 16) gelesen werden, der die Ergebnisse der ersten beiden Symposien dokumentiert. Die damals aufgeworfenen Fragen und behandelten Thematiken werden hier fortgeführt und weiterentwickelt....

  18. Humboldt Bay Orthoimages

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    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of 0.5-meter pixel resolution, four band orthoimages covering the Humboldt Bay area. An orthoimage is remotely sensed image data in which...

  19. Alejandro Von Humboldt

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    Gerardo Paz Otero

    1965-09-01

    Full Text Available Diverso fue y sigue siéndolo, el destino de los dos hermanos Humboldt, Guillermo y Alejandro. Sino que se inicia con el nacimiento: Guillermo, el mayor, nace el 22 de junio de 1767 en Potsdam, residencia de los emperadores prusianos, la ciudad de los palacios imperiales, el imperio del militarismo germano; su cuna se meció cerca al palacete de Sans-Soussi, donde Federico el Grande forja ba el poderío de Prusia, cultivaba las ciencias y las artes, anfitrionaba a los intelectuales de Europa, y era "vasallo espiritual de Volta ire", según la aguda frase de Goethe. Alejandro viene al mundo dos años después (14 de septiembre de 1769 en Berlín, en la casa burguesa de la Jagerstrasse (calle del cazador que su madre Elizabeth von Humboldt heredara de su primer esposo.

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

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

    2016-02-01

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

  1. Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: Comparing trophic linkages under La Niña and El Niño conditions

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    Tam, Jorge; Taylor, Marc H.; Blaskovic, Verónica; Espinoza, Pepe; Michael Ballón, R.; Díaz, Erich; Wosnitza-Mendo, Claudia; Argüelles, Juan; Purca, Sara; Ayón, Patricia; Quipuzcoa, Luis; Gutiérrez, Dimitri; Goya, Elisa; Ochoa, Noemí; Wolff, Matthias

    2008-10-01

    The El Niño of 1997-98 was one of the strongest warming events of the past century; among many other effects, it impacted phytoplankton along the Peruvian coast by changing species composition and reducing biomass. While responses of the main fish resources to this natural perturbation are relatively well known, understanding the ecosystem response as a whole requires an ecotrophic multispecies approach. In this work, we construct trophic models of the Northern Humboldt Current Ecosystem (NHCE) and compare the La Niña (LN) years in 1995-96 with the El Niño (EN) years in 1997-98. The model area extends from 4°S-16°S and to 60 nm from the coast. The model consists of 32 functional groups of organisms and differs from previous trophic models of the Peruvian system through: (i) division of plankton into size classes to account for EN-associated changes and feeding preferences of small pelagic fish, (ii) increased division of demersal groups and separation of life history stages of hake, (iii) inclusion of mesopelagic fish, and (iv) incorporation of the jumbo squid ( Dosidicus gigas), which became abundant following EN. Results show that EN reduced the size and organization of energy flows of the NHCE, but the overall functioning (proportion of energy flows used for respiration, consumption by predators, detritus and export) of the ecosystem was maintained. The reduction of diatom biomass during EN forced omnivorous planktivorous fish to switch to a more zooplankton-dominated diet, raising their trophic level. Consequently, in the EN model the trophic level increased for several predatory groups (mackerel, other large pelagics, sea birds, pinnipeds) and for fishery catch. A high modeled biomass of macrozooplankton was needed to balance the consumption by planktivores, especially during EN condition when observed diatoms biomass diminished dramatically. Despite overall lower planktivorous fish catches, the higher primary production required-to-catch ratio implied a

  2. Low noise SQUIDs

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    de Waal, V. J.

    1983-02-01

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

  3. Low noise SQUIDs

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, V.J.

    1983-01-01

    The present investigation deals with the design, fabrication, and limitations of very sensitive SQUID (Superconducting Quantum Interference Device) magnetometers. The SQUID magnetometer is based on a utilization of the Josephson effect. A description of the theoretical background is provided, and high performance DC SQUIDs with submicron niobium Josephson junctions are discussed, taking into account design considerations, fabrication, junction characterization, the performance of the SQUID and input coil, and the gradiometer performance. The simulation and optimization of a DC SQUID with finite capacitance is considered, giving attention to the implementation of a simulation procedure on a hybrid computer. 129 references.

  4. Hábitos alimentarios de Dosidicus gigas (D' Orbigny, 1835 (Cephalopoda: Teuthoidea frente a la costa centro-sur de Chile Feeding habits of Dosidicus gigas (D'Orbigny, 1835 (Cephalopoda: Teuthoidea in the central-south coast off Chile

    Directory of Open Access Journals (Sweden)

    PATRICIO ULLOA

    2006-12-01

    Full Text Available Se estudiaron los hábitos alimentarios del calamar rojo Dosidicus gigas (D'Orbigny, 1835 frente a la costa de Chile centro-sur, durante el invierno del año 2005. Se examinaron un total de 52 estómagos, en todos los cuales había contenido alimentario. Los ejemplares provenían de pescas efectuadas por la flota arrastrera industrial que opera entre 36°39' S y 38°55'S sobre la merluza común Merluccius gayi (Guichenot 1848 y a una profundidad media de 290 m sobre la plataforma continental. Para la descripción del espectro trófico, alimento principal y el establecimiento de las eventuales diferencias sexuales u ontogenéticas en la frecuencia de aparición de los ítemes presa, se utilizaron los métodos numérico, gravimétrico, de frecuencia de ocurrencia, índice de importancia relativa (IIR e índice de similitud porcentual (ISP. No se observaron diferencias sexuales ni ontogenéticas en la frecuencia de aparición de los ítemes presa. Los resultados muestran que D. gigas es un depredador oportunista, principalmente ictiófago, y secundariamente malacófago (incluye el canibalismo y carcinófago. Se discuten los eventuales motivos e implicancias de tal conductaA study on the feeding habits of the jumbo squid Dosidicus gigas (D'Orbigny, 1835 was carried out during the winter season 2005, in waters of the Chilean central and southern Pacific. A total of 52 jumbo squid stomachs from the fishing of the continental slope were collected and examined, in the Eighth and Ninth regions, between 36°40' S and 38°55'S, at an average depth of 290 m. To determine the trophic spectrum, the feeding preferences and the importance of the sex and ontogenetic condition in the diet, the numeric, gravimetric, frequency of occurrence methods, and the index of relative importance and dietary similarity were utilized. The frequency of the prey did not vary with relation to the sex and ontogenetic conditions, and was besides a hight trophic similarity in such

  5. Low noise SQUIDS

    International Nuclear Information System (INIS)

    Waal, V.J. de.

    1983-01-01

    The design, fabrication and limitations of very sensitive SQUID magnetometers are described. The SQUID magnetometer is based on the Josephson effect. A very low-noise niobium SQUID is described. It is fabricated with ultra-small niobium junctions with an overlapping area smaller than 1 μm 2 . The photolithographic technique developed for its fabrication, is described. Also an integrated system with a SQUID and a first-order gradiometer on a single substrate is presented. Calculations of the resolution of a dc SQUID containing ideal Josephson junctions according to the RSJ model are presented including a parasitic capacitance. The usefulness of the fabricated SQUIDS as well as some remarks on their performance is considered. (Auth.)

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

    Science.gov (United States)

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

    2012-03-01

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

  7. SQUID in NDT

    International Nuclear Information System (INIS)

    Rashdi Shah Ahmad

    2001-01-01

    Superconducting Quantum Interference Device (SQUID) is the most sensitive magnetic flux sensor. It has been used to map the magnetic field on the scalp of human being generated by the brain activity. Currently, a number of groups have tried using SQUID for some special NDT application. This paper reviews some of these work. (Author)

  8. The SQUID Handbook

    CERN Document Server

    Braginski, Alex I

    2006-01-01

    This two-volume handbook offers a comprehensive and well coordinated presentation of SQUIDs (Superconducting Quantum Interference Devices), including device fundamentals, design, technology, system construction and multiple applications. It is intended to bridge the gap between fundamentals and applications, and will be a valuable textbook reference for graduate students and for professionals engaged in SQUID research and engineering. It will also be of use to specialists in multiple fields of practical SQUID applications, from human brain research and heart diagnostics to airplane and nuclear

  9. Market Squid Ecology Dataset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains ecological information collected on the major adult spawning and juvenile habitats of market squid off California and the US Pacific Northwest....

  10. Market Squid Population Dynamics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains population dynamics data on paralarvae, juvenile and adult market squid collected off California and the US Pacific Northwest. These data were...

  11. Vortex electronis and squids

    CERN Document Server

    2003-01-01

    Understanding the nature of vortices in high-Tc superconductors is a crucial subject for research on superconductive electronics, especially for superconducting interference devices (SQUIDs), it is also a fundamental problem in condensed-matter physics. Recent technological progress in methods for both direct and indirect observation of vortices, e.g. scanning SQUID, terahertz imaging, and microwave excitation, has led to new insights into vortex physics, the dynamic behavior of vortices in junctions and related questions of noise. This book presents the current status of research activity and provides new information on the applications of SQUIDs, including magnetocardiography, immunoassays, and laser-SQUID microscopes, all of which are close to being commercially available.

  12. SQUID application research in Japan

    International Nuclear Information System (INIS)

    Itozaki, Hideo

    2003-01-01

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

  13. Hypoxia tolerance and antioxidant defense system of juvenile jumbo squids in oxygen minimum zones

    Science.gov (United States)

    Trübenbach, Katja; Teixeira, Tatiana; Diniz, Mário; Rosa, Rui

    2013-10-01

    Jumbo squid (Dosidicus gigas) is a large oceanic squid endemic off the Eastern Tropical Pacific that undertakes diel vertical migrations into mesopelagic oxygen minimum zones. One of the expected physiological effects of such migration is the generation of reactive oxygen species (ROS) at the surface, promoted by the transition between hypoxia and reoxygenation states. The aim of this study was to investigate the energy expenditure rates and the antioxidant stress strategies of juvenile D. gigas under normoxia and hypoxia, namely by quantifying oxygen consumption rates, antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], heat shock protein expression (Hsp70/Hsc70), and lipid peroxidation [malondialdehyde (MDA) levels]. A high significant decrease (68%) in squid's metabolic rates was observed during hypoxia (p0.05), with the latter indicating no enhancement of lipid peroxidation (i.e. cellular damage) at the warmer and normoxic surface waters. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how this species is quickly responding to the impacts of environmental stressors coupled with global climate change.

  14. The Stationary SQUID

    Science.gov (United States)

    Berger, Jorge

    2018-06-01

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

  15. Humboldt Bay, California Benthic Habitats 2009 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  16. Humboldt, California 1 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1-second Humboldt, California Elevation Grid provides bathymetric data in ASCII raster format of 1-second resolution in geographic coordinates. This grid is...

  17. Humboldt Bay Benthic Habitats 2009 Aquatic Setting

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  18. Humboldt Bay, California Benthic Habitats 2009 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  19. Humboldt Bay, California Benthic Habitats 2009 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  20. Cryostats for SQUID magnetometers

    International Nuclear Information System (INIS)

    Testard, O.A.; Locatelli, M.

    1982-05-01

    A non metallic and non magnetic cryostat, with a very low thermal budget and a container type autonomy was developed, to condition S.Q.U.I.D. magnetometers which maximum sensitivity reaches 10 -14 Tesla Hertzsup(-1/2). This instrumentation puts in hand new concepts of composite materials, thermal shock and vibration resistant, multilayer thermal radiative insulation also to the prouve of vibrations with thermal equivalent emissivity lower than 10 -3

  1. Humboldt Open Ocean Disposal Site (HOODS) Survey Work 2014

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Humboldt Open Ocean Disposal Site (HOODS) is a dredged material disposal site located 3 nautical miles (nm) offshore of Humboldt Bay in Northern California....

  2. A Metabiography of Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Nicolaas A. Rupke

    2006-04-01

    Full Text Available Article in English.The author's recently published monograph on Alexander von Humboldt describes the multiple images of this great cultural icon. The book is a metabiographical study that shows how from the middle of the nineteenth century to the present day Humboldt has served as a nucleus of crystallisation for a variety of successive socio-political ideologies, each producing its own distinctive representation of him. The historiographical implications of this biographical diversity are profound and support current attempts to understand historical scholarship in terms of memory cultures.

  3. SQUID technology for geophysical exploration

    International Nuclear Information System (INIS)

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

    2005-01-01

    We report on successful tests of planar LTS SQUID gradiometers on airborne platforms such as helicopter and aircraft. The system works stable and allows profile work without any constraints. In mobile applications the gradient resolution at low frequencies is dominated by motion noise, since the parasitic areas of the SQUID gradiometer lead to strong disturbances if the gradiometer is tilted in the homogenous Earth's magnetic field. The balance can be improved further by software using data of a SQUID magnetometer triple. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. 33 CFR 165.1195 - Regulated Navigation Area; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt...

    Science.gov (United States)

    2010-07-01

    ... Entrance Channel, Humboldt Bay, California. (b) Definitions. As used in this section— COTP means the... person in charge of a vessel to which this notice applies shall obtain permission to cross within four... place during daylight hours, the vessel has only a single tow or no tow, the visibility at the bar is...

  5. Geschichte der Natur bei Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Christian Helmreich

    2009-05-01

    Full Text Available Article in German, Abstracts in English, German and French.This article analyses the importance of an historical view of nature in the works of Alexander von Humboldt. In several of his first writings, Humboldt seems to outline the importance of what one may call history of nature. But even before his famous American travel, his position changed and he became reluctant to accept the seriousness of historical enquiry in the area of natural sciences: if we want to reconstruct the past state of nature, we cannot rely on empirical proofs; and history of nature is therefore necessarily based on uncertain hypotheses. Humboldt kept his sceptical attitude in the first decades of the 19th century, despite the positive results of the palaeontological researches of his scientific colleagues. However, he gradually convinced himself of the scientific interest of historical investigations in the natural sciences. The Cosmos paradoxally displays two apparently conflicting points of view: in his methodological remarks, Humboldt maintains that precise accounts of the past state of nature are out of reach of human knowledge, yet elsewhere in the same Cosmos he gives broad and rather vivid descriptions of the eventful history of nature.

  6. Alexander von Humboldt and Coenraad Jacob Temminck

    NARCIS (Netherlands)

    Raat, A.J.P.

    1976-01-01

    INTRODUCTION In the archives of the Rijksmuseum van Natuurlijke Historie in Leiden there is a map with three letters written by Alexander von Humboldt (17691859) to the first director of the Museum, Coenraad Jacob Temminck (1778-1858). The map, the hard cover of John Gould's "Synopsis of the birds

  7. Research, design and education, Von Humboldt revisited

    NARCIS (Netherlands)

    Bax, M.F.T.; Doevendans, C.H.; Trum, H.M.G.J.; Langenhuizen, Anja; Ouwerkerk, Marieke van; Rosemann, Jurgen

    2001-01-01

    This paper is a result of reflection on the interrelation design-research-cultivation, and on the interpretation of Von Humboldt's maxim: 'Einheit von Forschung und Lehre', which governed the academic world in the past two centuries. It is argued that 'Forschung' should be interpreted as 'Research

  8. Characteristics regarding the consumer of giant squid from Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Liliana Enriqueta Montaño Méndez

    2015-01-01

    Full Text Available The catch of the giant squid (Dosidicus gigas, represents de second fishing activity most important in volume in Baja California Sur, Mexico; is an essential specie not only at the state level but at the pacific and even the national level. Mexico occupies in the world the eight level in the production of squid, but the national consumption, even though the low price of the product and the high nutritional level, is approximately 0.53 kg per year, very low compared to countries like Japan, Korea and Spain (average consumption per capita is of 3.5 kg . In this context, the objective of this article is to caracterize the sudcalifornia consumer preference; determine the buying habits and the consumption; and also to establish the market areas of the squid in Baja California Sur, which allows the introduction of actions for its commercialization, in order to strengthen the market of this product and its general activity. This is why in 2012 a questioner of 1066 consumers was distribute around the five counties of the state, according to the population density. The results indicate that the principal motive why there is not consumption is the difficulty to find places where to buy it, together with the problems of cooking it. Also, it can be seen the high level of ignorance the consumer has regarding the nutritional level this food has. For this reason, future strategies for the commercialization must be focus on better distribution and new form of presenting this product which facilitates its preparation and consumption, and at the same time create campaign which increase awareness of the nutrition level this product has.

  9. Paleomagnetic Analysis Using SQUID Microscopy

    Science.gov (United States)

    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.

  10. Ludwig Leichhardt und Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Aliya-Katarina Südfels

    2012-10-01

    Full Text Available Zusammenfassung Im Juli des Jahres 1841 kommt es zu einem Treffen zwischen zwei Männern, das zunächst belanglos erscheint, sich aber Jahre später als wichtige historische Begebenheit herausstellen wird. In seinem Pariser Büro empfängt der 71jährige Naturforscher Alexander von Humboldt den jungen Preußen Ludwig Leichhardt. Der angehende Naturwissenschaftler erhofft sich Zuspruch und Empfehlung des berühmten Alexander von Humboldts. Die Unterredung ist kurz und verläuft für Leichhardt ergebnislos. Es wird das einzige Treffen der beiden Naturwissenschaftler bleiben. Aus heutiger Sicht unverständlich, da Ludwig Leichhardt und Alexander von Humboldt mehr verband, als ihre Leidenschaft für die Naturwissenschaften. Viel zu wenig ist sich bis jetzt den biographischen Analogien und den vergleichbaren geographischen Leistungen der beiden Preußen gewidmet worden. Abstract During July 1841 a meeting between two men takes place, which seems to have been extraneous, but turns out to be a significant historical incident. 71 year old natural scientist Alexander von Humboldt welcomes young Ludwig Leichhardt from Prussia in his office in Paris. The prospective young scientist expects help and references from famous Alexander von Humboldt. The conversation is short and ends from Leichhardt’s point of view without results. Unfortunately this is going to be the only meeting between the two scientists even though the two Prussians have more in common than their passion for the natural sciences. Way too seldomly have biographical analogy and geographical productivity of the two men been compared. Résumé En juillet 1841 une rencontre entre deux hommes a lieu, qui au premier abord semble sans importance, mais qui des années plus tard est considéré comme un événement historique majeur. Dans son bureau parisien, le naturaliste Alexandre de Humboldt, alors âgé de 71 ans, reçoit le jeune Prussien Ludwig Leichhardt. Le jeune scientifique en devenir

  11. Tracking Electromagnetic Energy With SQUIDs

    Science.gov (United States)

    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.

  12. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    Science.gov (United States)

    2015-09-30

    an area important for acoustical testing and tactical exercises, the most abundant species by biomass is Pacific hake, Merluccius productus, a fish...scattering characteristics of the animal especially if the animal has eaten hard- shelled mollusc prey. Figure 7. A dorsal scan (similar to an x-ray) of a...kHz echogram. 11 In order to generate abundance and biomass estimates for organisms using active acoustics, one assumption that can be made is

  13. SQUID-based measuring systems

    Indian Academy of Sciences (India)

    field produced by a given two-dimensional current density distribution is inverted using the Fourier transform technique. Keywords ... Superconducting quantum interference devices (SQUIDs) are the most sensitive detectors for measurement of ... omagnetic prospecting, detection of gravity waves etc. Judging the importance ...

  14. Compact integrated dc SQUID gradiometer

    Science.gov (United States)

    de Waal, V. J.; Klapwijk, T. M.

    1982-10-01

    An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17×12 mm and a sensitivity of 3.5×10-12 T m-1 Hz-1/2.

  15. Compact integrated dc SQUID gradiometer

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, V.J.; Klapwijk, T.M.

    1982-10-01

    An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17 x 12 mm and a sensitivity of 3.5 x 10/sup -12/ T m/sup -1/ Hz/sup -1/2/.

  16. Squids: applications outside the laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Falco, C M

    1978-07-01

    Originally thought to be rather esoteric, SQUIDS (superconducting quantum interference devices) have moved from the realms of theory to practical application since 1962. The promise for the not-too-distant future is a superconducting computer, with 10/sup 5/ logic elements in a 1cm cube.

  17. STM-SQUID probe microscope

    International Nuclear Information System (INIS)

    Hayashi, Tadayuki; Tachiki, Minoru; Itozaki, Hideo

    2007-01-01

    We have developed a STM-SQUID probe microscope. A high T C SQUID probe microscope was combined with a scanning tunneling microscope for investigation of samples at room temperature in air. A high permeability probe needle was used as a magnetic flux guide to improve the spatial resolution. The probe with tip radius of less than 100 nm was prepared by microelectropolishing. The probe was also used as a scanning tunneling microscope tip. Topography of the sample surface could be measured by the scanning tunneling microscope with high spatial resolution prior to observation by SQUID microscopy. The SQUID probe microscope image could be observed while keeping the distance from the sample surface to the probe tip constant. We observed a topographic image and a magnetic image of Ni fine pattern and also a magnetically recorded hard disk. Furthermore we have investigated a sample vibration method of the static magnetic field emanating from a sample with the aim of achieving a higher signal-to-noise (S/N) ratio

  18. Cold SQUIDs and hot samples

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-01

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

  19. How the SQUID was born

    International Nuclear Information System (INIS)

    Silver, Arnold H

    2006-01-01

    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

  20. Properties of high temperature SQUIDS

    International Nuclear Information System (INIS)

    Falco, C.M.; Wu, C.T.

    1978-01-01

    A review is given of the present status of weak links and dc and rf biased SQUIDs made with high temperature superconductors. A method for producing reliable, reproducible devices using Nb 3 Sn is outlined, and comments are made on directions future work should take

  1. Cold SQUIDs and hot samples

    International Nuclear Information System (INIS)

    Lee, T.S.C.; Lawrence Berkeley national Lab., CA

    1997-05-01

    Low transition temperature (low-T c ) and high-T c 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-T c superconductors using two low-T c 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-T c SQUID microscope optimized for imaging room-temperature objects with very high spatial resolution and magnetic source sensitivity

  2. How the SQUID was born

    Energy Technology Data Exchange (ETDEWEB)

    Silver, Arnold H [Northrop Grumman Space Technology, One Space Park, Redondo Beach, CA 90278 (United States)

    2006-05-15

    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.

  3. Alexander von Humboldt and British artists: the Oriental taste

    Directory of Open Access Journals (Sweden)

    Garrido, Elisa

    2013-12-01

    Full Text Available Humboldtian landscape is the best result of a close relationship between artists and scientists in the context of the Enlightenment. Many artists inspired Humboldt to develop his concept of landscape as the best way of representing Nature, but some British artists in particular were a strong reference for him. Thomas Daniell and William Hodges had travelled to Asia creating a particular imagery, which inspired the desire to travel and the feeling of the exotic taste in Humboldt. Around Humboldt, mainly two types of artists have been studied: on the one hand, painter travellers who received direct instructions from Humboldt after his experience in America, and on the other, artists who started their trips by themselves after reading his works. However, this paper is focused on the links between Humboldt and these British painters of the Orient, whom he met on a European tour with Georg Forster, before making his trip to America.El paisaje teorizado por Humboldt es el resultado de una estrecha relación entre artistas y científicos, en el contexto de la Ilustración. Muchos artistas inspiraron a Humboldt a desarrollar su concepto del paisaje como la mejor forma de representar la naturaleza pero particularmente, algunos artistas británicos supusieron una fuerte referencia para él. Principalmente, alrededor de Humboldt se han estudiado dos tipos de artistas: por una parte, los pintores viajeros que recibieron instrucciones directas de Humboldt tras su experiencia en América y por otra, los artistas que iniciaron sus viajes por iniciativa propia tras haber leído los sus trabajos. Sin embargo, este texto se centra en las relaciones entre Humboldt y los pintores británicos de Oriente, a quienes él conoció en su viaje europeo junto a Georg Forster, antes de realizar su viaje americano.

  4. NanoSQUIDs: Basics & recent advances

    Science.gov (United States)

    José Martínez-Pérez, Maria; Koelle, Dieter

    2017-08-01

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

  5. Hypertextuality in the Alexander von Humboldt Digital Library

    Directory of Open Access Journals (Sweden)

    Detlev Doherr

    2016-04-01

    Full Text Available To do justice to the legacy of Alexander von Humboldt, a 19th century German scientist and explorer an information and knowledge management system is required to preserve the author's original intent and promote an awareness of all his relevant works. Although all of Humboldt's works can be found on the internet as digitized papers, the complexity and internal interconnectivity of the writings is not very transparent. Humboldt's concepts of interaction cannot be adequately represented only by digitized papers or scanned documents. The Humboldt Portal is an attempt to create a new generation of digital libraries, providing a new form of interaction and synthesis between humanistic texts and scientific observation. The digital version of his documents supplies dynamic links to sources, maps, images, graphs and relevant texts in accordance with his visions, because "everything is interconnectedness".

  6. Eureka Littoral Cell CRSMP Humboldt Bay Shoreline Types 2011

    Data.gov (United States)

    California Natural Resource Agency — In 2011 Aldaron Laird walked and kayaked the entire shoreline of Humboldt Bay mapping the shoreline conditions onto 11x17 laminated fieldmaps at a scale of 1' = 200'...

  7. Alexandre de Humboldt et le Marquis de Laplace

    Directory of Open Access Journals (Sweden)

    Eberhard Knobloch

    2014-12-01

    Full Text Available Pierre-Simon Marquis de Laplace joua un rôle éminent dans la vie scientifique d’Alexandre de Humboldt. Humboldt avait fait la connaissance du savant français qui avait vingt ans de plus que lui-même à Paris en 1798. L’article de Eberhard Knobloch examine la relation entre ces deux géants de la science en s’appuyant entre autre pour la première fois sur des documents inédits: les quatre lettres de Laplace à Humboldt, le journal d’Humboldt et sur le matériel d’archives conservé aux Archives de l’Académie des Sciences de Berlin-Brandebourg.

  8. Alexandre de Humboldt et le Marquis de Laplace

    OpenAIRE

    Eberhard Knobloch

    2014-01-01

    Pierre-Simon Marquis de Laplace joua un rôle éminent dans la vie scientifique d’Alexandre de Humboldt. Humboldt avait fait la connaissance du savant français qui avait vingt ans de plus que lui-même à Paris en 1798. Si l’on n’étudie pas seulement leurs œuvres, mais aussi leurs correspondances et le journal américain d’Humboldt, on en conclut qu’il faut réviser l’impression superficielle qui se dégage des publications d’Humboldt. L’estime réciproque entre les deux hommes ne se mit en place que...

  9. Ein Humboldt-Brief in der Autographensammlung Lion Feuchtwangers

    Directory of Open Access Journals (Sweden)

    Ingo Schwarz

    2006-10-01

    Full Text Available Article in German, Abstracts in English and German.The paper deals with a letter from Alexander von Humboldt, which has been part of Lion Feuchtwanger's Autograph Collection since 1958. An investigation of the contents of the letter brought to light new details, chiefly of Humboldt's activities in promoting young talents. Emil Naumann (1827-1888, composer, teacher and author, was clearly identified as the letter's recipient.

  10. Humboldt SK pilot biodigester receives funding

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-09-30

    The Canada-Saskatchewan Western Economic Partnership Agreement (WEPA) will provide funding for Canada's first pilot-scale biodigester to be built in Humboldt, Saskatchewan. The $208,138 pilot facility will use household garbage as well as agricultural waste such as manure and livestock operations, abattoirs and food processing to create heat or power and fertilizer. Support for this bio-energy facility, which could also reduce greenhouse gases, will come from the Prairie Agricultural Machinery Institute which has received $186,138 from Canada and Saskatchewan in the form of cost-shared federal-provincial funding. The pilot plant will test different combinations of waste material feedstocks and the characteristics of the resulting gas end products. The pilot facility will also provide design information for full-scale biodigester manufacturers in Canada. It is expected that 25 full-scale biodigesters will be constructed in Canada in the near future.

  11. A new integrated microwave SQUID circuit design

    International Nuclear Information System (INIS)

    Erne, S.N.; Finnegan, T.F.

    1980-01-01

    In this paper we consider the design and operation of a planar thin-film rf-SQUID circuit which can be realized via microwave-integrated-circuit (MIC) techniques and which differs substantially from pervious microwave SQUID configurations involving either mechanical point-contact or cylindrical thin-film micro-bridge geometries. (orig.)

  12. Preliminary results of hydrogeologic investigations Humboldt River Valley, Winnemucca, Nevada

    Science.gov (United States)

    Cohen, Philip M.

    1964-01-01

    Most of the ground water of economic importance and nearly all the ground water closely associated with the flow o# the Humboldt River in the. 40-mile reach near Winnemucca, Nev., are in unconsolidated sedimentary deposits. These deposits range in age from Pliocene to Recent and range in character from coarse poorly sorted fanglomerate to lacustrine strata of clay, silt, sand, and gravel. The most permeable deposit consists of sand and gravel of Lake Lahontan age--the so-called medial gravel unit--which is underlain and overlain by fairly impermeable silt and clay also of Lake Lahontan age. The ultimate source of nearly all the water in the study area is precpitation within the drainage basin of the Humboldt River. Much of this water reaches the study, area as flow or underflow of the Humboldt River and as underflow from other valleys tributary to the study area. Little if any flow from the tributary streams in the study area usually reaches the Humboldt River. Most of the tributary streamflow within the study area evaporates or is transpired by vegetation, but a part percolates downward through unconsolidated deposits of the alluvial fans flanking the mountains and move downgradient as ground-water underflow toward the Humboldt River. Areas that contribute significant amounts of ground-water underflow to. the valley of the Humboldt River within the study area are (1) the valley of the Humboldt River upstream from the study area, (2) the Pole Creek-Rock Creek area, (3) Paradise Valley, and (4) Grass Valley and the northwestern slope of the Sonoma Range. The total average underflow from these areas in the period 1949-61 was about 14,000-19,000 acre-feet per year. Much of this underflow discharged into the Humboldt River within the study area and constituted a large part of the base flow of the river. Streamflow in the Humboldt River increases substantially in the early spring, principally because of runoff to the river in the reaches upstream from the study area

  13. Review of SQUID Sensors for Measuring Magnetocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. H.; Kim, J. M.; Yu, K. K.; Kim, K.; Kwon, H. [Brain and Cognition Measurement Lab, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2011-08-15

    Measurement of magnetic signals generated from electric activity of myocardium provides useful information for the functional diagnosis of heart diseases. Key technical component of the magnetocardiography (MCG) technology is SQUID. To measure MCG signals with high signal-to-noise ratio, sensitive SQUID magnetic field sensors are needed. Present magnetic field sensors based on Nb SQUIDs have field sensitivity good enough to measure most of MCG signals. However, for accurate measurement of fine signal pattern or detection of local atrial fibrillation signals, we may need higher field sensitivity. In addition to field sensitivity, economic aspect of the SQUID system is also important. To simplify the SQUID readout electronics, the output voltage or flux-to-voltage transfer of SQUID should be large enough so that direct measurement of SQUID output can be done using room-temperature preamplifiers. Double relaxation oscillation SQUID (DROS), having about 10 times larger flux-to-voltage transfers than those of DC-SQUIDs, was shown to be a good choice to make the electronics compact. For effective cancellation of external noise inside a thin economic shielded room, first-order axial gradiometer with high balance, simple structure and long-baseline is needed. We developed a technology to make the axial gradiometer compact using direct bonding of superconductive wires between pickup coil and input coil. Conventional insert has mechanical support to hold the gradiometer array, and the dewar neck has equal diameter with the dewar bottom. Boiling of the liquid He can generate mechanical vibrations in the gradiometer array due to mechanical connection structure. Elimination of the mechanical support, and direct mounting of the gradiometer array into the dewar bottom can reduce the dewar neck diameter, resulting in the reduction of liquid He consumption.

  14. Psychological Analysis of "Humboldt's Gift" from the Perspective of Lacan's Theory

    Science.gov (United States)

    Xiang, Fang

    2017-01-01

    Two protagonists Humboldt and Citrine in "Humboldt's gift" are characterized as restless even lunatic, for they are constantly or madly seeking something such as honor, power or intimate relationship something or other. This thesis intends to analyze Humboldt and Citrine's psychological troubles from the perspective of Lacan's theory and…

  15. 76 FR 31846 - Safety Zone; 28th Annual Humboldt Bay Festival, Fireworks Display, Eureka, CA

    Science.gov (United States)

    2011-06-02

    ...-AA00 Safety Zone; 28th Annual Humboldt Bay Festival, Fireworks Display, Eureka, CA AGENCY: Coast Guard... support of the 28th Annual Humboldt Bay Festival Fireworks Display on the specified waters off the South... Humboldt Bay Festival Fireworks Display. The fireworks display is for entertainment purposes. This safety...

  16. Alexander von Humboldt und die transnationale Wissenschaftskommunikation im 19. Jahrhundert

    Directory of Open Access Journals (Sweden)

    Ulrich Päßler

    2008-10-01

    Full Text Available Article in german, abstracts in english and frenchAlexander von Humboldt has been labelled a “scientific cosmopolitan”. Through his vast correspondence and a network of personal contacts, he upheld a form of scientific exchange that was characteristic of the eighteenth-century “republic of letters”.This article examines how Humboldt adapted this cosmopolitan tradition of communication to a nineteenth century scientific culture that was largely institutionalized and was becoming increasingly nationalized. Humboldt quite successfully fostered scientific exchange between Berlin and Paris after 1830 and, on various occasions between the 1830s and 1850s, readily advocated international large-scale projects. These examples demonstrate that Humboldt observed the development of nationally defined scientific cultures and the opening of the sciences towards the public realm. Moreover, they indicate how he was able to make use of these developments as he promoted the sciences in Prussia. In scientific controversies within the Parisian scientific community, Humboldt was involuntarily assigned the role of a “neutral” foreign arbitrator. Thus, the development of nineteenth century sciences also jeopardized Humboldt’s unique position as an independent “homme des lettres”.

  17. Acceleration of Humboldt glacier, north Greenland

    Science.gov (United States)

    Jeong, S.; Howat, I.; Noh, M. J.; King, M. D.

    2017-12-01

    Here we report on recent abrupt acceleration on the flow speed of Humboldt Glacier (HG) in northern Greenland. The mean annual discharge of this glacier in 2000 was estimated as 8.4Gt/a, placing it among the largest outlet glacier draining the northern coast (Enderlin et al., 2014). Using a combination of remote sensing datasets, we find that following a slight slowing before 2010, HG suddenly sped up by a factor of three between 2012 and 2013, maintaining that increased speed through 2016. Speedup was accompanied by up to 10 m of thinning near the terminus and followed slower, longer-term thinning and retreat. Here we assess possible causes for the speedup, potential for continued acceleration and implication to ice sheet mass balance. ReferenceEnderlin, E. M., I. M. Howat, S. Jeong, M.-J. Noh, J. H. van Angelen, and M. R. van den Broeke (2014), An improved mass budget for the Greenland ice sheet, Geophys. Res. Lett., 41, 866-872, doi:10.1002/2013GL059010.

  18. Squid based beam current meter

    International Nuclear Information System (INIS)

    Kuchnir, M.

    1983-01-01

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

  19. New version of toroidal SQUID sensor

    International Nuclear Information System (INIS)

    Zarembinski, S.; Kachniarz, J.

    1983-01-01

    A report is given on the design and fabrication of a mechanically stable and thermal shock resistant SQUID sensor. The sensor is vacuum sealed while the access to the adjustment of its point contact is left open

  20. Die Ordnung der Weltkulturen. Alexander von Humboldts Ansichten der Kultur

    Directory of Open Access Journals (Sweden)

    Ottmar Ette

    2004-10-01

    Full Text Available Article in German,Abstracts in English, German and Spanish. Focussing Alexander von Humboldt's Vues des Cordillères et Monumens des peuples indigènes de l'Amérique (1810 - 1813 in the context of his monumental work, this essay tries to highlight not only the creation of a new discourse on the Americas but, at the same time, the project(ion of a new order of world cultures. From a transregional perspective, Humboldt's aesthetically most radical book can be fully understood as a musée imaginaire of world cultures whose spatial, temporal, social, literary, frictional, architextual and cultural dimensions allow new insights in one of the most fascinating texts of the early 19th century. Alexander von Humboldt's Vues are creating a transmedial kaleidoscope within a fractal vision of the cultures of the world in the second period of accelerated globalization.

  1. YBCO SQUIDs with unconventional current phase relation

    International Nuclear Information System (INIS)

    Bauch, T.; Johansson, J.; Cedergren, K.; Lindstroem, T.; Lombardi, F.

    2007-01-01

    We have studied the dynamics of YBa 2 Cu 3 O 7-δ (YBCO) dc sperconducting quantum interference devices (SQUIDs) characterized by an unconventional Josephson current phase relation (CPR). We have focused on SQUID configurations with Josephson junctions where the lobe of the order parameter in one electrode is facing a node in the other electrode. This order parameter arrangement should enhance the appearance of a sin(2φ) term in the CPR. The response of the critical current of the dc SQUID, under the effect of an external magnetic field, has been measured in temperature, down to 20 mK. Our experimental data have been compared with numerical simulations of the SQUIDs dynamics by considering a CPR of a single junction of the form I(φ) = I I sin(φ) - I II sin(2φ) where I I and I II are, respectively, the first and second harmonic component. In our devices the values of the sin(2φ) term are such that the fundamental state of the SQUID is naturally double degenerate. This is of great relevance for applications of d-wave SQUIDs in quantum information processing

  2. The Journal of A. v. Humboldt in Spain

    Directory of Open Access Journals (Sweden)

    Leitner, Ulrike

    2011-12-01

    Full Text Available The Spanish diary can surprisingly not be found in his bounded diaries from his American travels, but in a separate folder of his legacy in Berlin, where Humboldt collected material which he wanted to use for his publication about Spain. So it remained undiscovered until recently. Humboldt’s notes contain geognostic descriptions as well as his observations about climate, vegetation, electricity of the atmosphere, etc. The comparison with Humboldt’s publication of 1825 facilitates to gain insight into his scientific methods.

    El diario español de Humboldt se encuentra sorprendentemente en una carpeta de su legado en Berlín, donde el mismo recopiló los materiales para su publicación sobre la meseta española en la revista Hertha, y no en sus diarios encuadernados del viaje americano. Esto explica que no se hubieran descubierto hasta hace poco tiempo. El manuscrito contiene descripciones geognósticas, observaciones sobre el clima, la vegetación, la electricidad de la atmósfera, etc. La comparación con lo publicado de Humboldt en 1825 sobre la meseta española que realizamos en las notas de esta edición facilitará al lector una aproximación a los métodos cientificos típicos de Humboldt.

  3. Alexander von Humboldt's invention of the natural landscape

    NARCIS (Netherlands)

    Kwa, C.

    2005-01-01

    Landscape took on a new meaning through the new science of plant geography of Alexander von Humboldt (1769-1857). In the seventeenth and eighteenth centuries, "landscape" was foremost a painterly genre. Slowly, painted landscapes came to bear on natural surroundings, but by 1800 it was still not

  4. Virgin Valley opal district, Humboldt County, Nevada

    Science.gov (United States)

    Staatz, Mortimer Hay; Bauer, Herman L.

    1951-01-01

    The Virgin Valley opal district, Humboldt County, Nevada, is near the Oregon-Nevada border in the Sheldon Game Refuge. Nineteen claims owned by Jack and Toni Crane were examined, sampled, and tested radiometrically for uranium. Numerous discontinuous layers of opal are interbedded with a gently-dipping series of vitric tuff and ash which is at least 300 ft thick. The tuff and ash are capped by a dark, vesicular basalt in the eastern part of the area and by a thin layer of terrace qravels in the area along the west side of Virgin Valley. Silicification of the ash and tuff has produced a rock that ranges from partly opalized rock that resembles silicified shale to completely altered rock that is entirely translucent, and consists of massive, brown and pale-green opal. Carnotite, the only identified uranium mineral, occurs as fracture coatings or fine layers in the opal; in places, no uranium minerals are visible in the radioactive opal. The opal layers are irregular in extent and thickness. The exposed length of the layers ranges from 8 to 1, 200 ft or more, and the thickness of the layers ranges from 0. 1 to 3. 9 ft. The uranium content of each opal layer, and of different parts of the same layer, differs widely. On the east side of Virgin Valley four of the seven observed opal layers, nos. 3, 4, 5, and 7, are more radioactive than the average; and the uranium content ranges from 0. 002 to 0. 12 percent. Two samples, taken 5 ft apart across opal layer no. 7, contained 0. 003 and 0. -049 percent uranium. On the west side of the valley only four of the fifteen observed opal layers, nos; 9, , 10, 14, and 15, are more radioactive than the average; and the uranium content ranges from 0. 004 to 0. 047 percent. Material of the highest grade was found in a small discontinuous layer of pale-green opal (no. 4) on the east side of Virgin Valley. The grade of this layer ranged from 0. 027 to 0. 12 percent uranium.

  5. Radiation detection from phase-locked serial dc SQUID arrays

    DEFF Research Database (Denmark)

    Kaplunenko, V. K.; Mygind, Jesper; Pedersen, Niels Falsig

    1993-01-01

    We report on synchronous operation of series arrays of inductively coupled superconducting quantum interference devices (SQUIDs). Each array consisted of N=3 or 11 dc SQUIDs with common inductances providing a strong interaction between neighboring cells. Externally shunted (betac[approximately-e......We report on synchronous operation of series arrays of inductively coupled superconducting quantum interference devices (SQUIDs). Each array consisted of N=3 or 11 dc SQUIDs with common inductances providing a strong interaction between neighboring cells. Externally shunted (betac...

  6. Squids: principles and basic applications in experimental physics

    International Nuclear Information System (INIS)

    Ocio, M.

    1990-01-01

    The basic principles and the description of the technical aspects of SQUIDs (Superconducting Quantum Interference Devices) are described. The applications of SQUIDs in experimental researches and low temperature physics experiments are given. The concepts of fluxoid quantization in a superconductor and Josephson tunnelling are reviewed. The principles, the operation, the noise and the different configurations of r.f. and direct current bias SQUIDs are summarized. The principal characteristics of several SQUIDs are reported

  7. The investigation of rf-squids at liquid nitrogen temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Polushkin, V N; Vasiliev, B V [Joint Inst. for Nuclear Research, Dubna (USSR)

    1989-12-01

    One- and two-hole YBCO ceramic rf-squids operating at liquid nitrogen temperatures have been developed. The main squid parameters: self-inductance, white noise level and magnetic flux resolution were measured. The directly measured external field sensitivity for one-hole squid was at the level of 100 fT/{radical}Hz. (orig.).

  8. The use of (double) relaxation oscillation SQUIDs as a sensor

    NARCIS (Netherlands)

    van Duuren, M.J.; Brons, G.C.S.; Kattouw, H.; Flokstra, Jakob; Rogalla, Horst

    1997-01-01

    Relaxation Oscillation SQUIDs (ROSs) and Double Relaxation Oscillation SQUIDs (DROSs) are based on relaxation oscillations that are induced in hysteretic dc SQUIDs by an external L-R shunt. The relaxation frequency of a ROS varies with the applied flux Φ, whereas the output of a DROS is a dc

  9. Computer model for noise in the dc Squid

    International Nuclear Information System (INIS)

    Tesche, C.D.; Clarke, J.

    1976-08-01

    A computer model for the dc SQUID is described which predicts signal and noise as a function of various SQUID parameters. Differential equations for the voltage across the SQUID including the Johnson noise in the shunted junctions are integrated stepwise in time

  10. Well coupled, low noise, dc SQUIDS

    International Nuclear Information System (INIS)

    Muhlfelder, B.; Beall, J.A.; Cromar, M.W.; Johnson, W.W.; Ono, R.H.

    1985-01-01

    The authors have designed, fabricated, and tested a Double Transformer (DT) coupled dc SQUID (Superconducting Quantum Interference Device) with low noise, an input inductance of 1μH and a smooth input-output characteristic. A transmission line model is presented to explain a resonance in the input-output characteristic of early versions of this device. Guided by the results of numerical simulations a new version of this device has been built and tested. Experimental results are presented that show that the resonance can be moved to a higher voltage by reducing the area of the SQUID loop. The voltage-external flux characteristic of some of these new devices agrees to within 10% with computer simulations. The minimum detectable energy per unit bandwidth (MDE) referred to the SQUID loop, is 10h, where h is Planck's constant. Computer simulations indicate an MDE of 6h

  11. Parameter tolerance of the SQUID bootstrap circuit

    International Nuclear Information System (INIS)

    Zhang Guofeng; Dong Hui; Xie Xiaoming; Jiang Mianheng; Zhang Yi; Krause, Hans-Joachim; Braginski, Alex I; Offenhäusser, Andreas

    2012-01-01

    We recently demonstrated and analysed the voltage-biased SQUID bootstrap circuit (SBC) conceived to suppress the preamplifier noise contribution in the absence of flux modulation readout. Our scheme contains both the additional voltage and current feedbacks. In this study, we analysed the tolerance of the SBC noise suppression performance to spreads in SQUID and SBC circuit parameters. Analytical results were confirmed by experiments. A one-time adjustable current feedback can be used to extend the tolerance to spreads such as those caused by the integrated circuit fabrication process. This should help to improve the fabrication yield of SBC devices integrated on one chip—as required for multi-channel SQUID systems.

  12. Decommissioning of the Humboldt Bay Power Plant, Unit No. 3, Docket No. 50-133, Humboldt County, California

    International Nuclear Information System (INIS)

    1987-04-01

    Environmental impacts associated with the SAFSTOR option for decommissioning the Humboldt Bay Power Plant, Unit 3, located four miles southwest of the city of Eureka in Humboldt County, California, are assessed. Humboldt Bay Unit 3, a 65-MWe boiling water reactor, was operated commercially from August 1963 until July 1976, at which time it was shut down for seismic modifications. The facility would be stored safely for approximately 30 years. Estimated annual purchases of materials and supplies resulting from SAFSTOR activities are expected to be $20,000 (1984 dollars), and these purchases are expected to be made in Humboldt County. A fuel-handling accident would result in atmospheric radionuclide releases that are well below EPA Protective Action Guide (PAG) levels. Damage to all the stored-fuel assemblies resulting from a nonmechanistic heavy-load drop would result in atmospheric radionuclide releases that are also well below the PAG levels. There is a negligibly small likelihood that seismic loads or other mechanical loads would generate criticality among the spent fuel assemblies stored in the pool. The upper limits of potential lung, liver, and bone doses resulting from an instantaneous expulsion to the atmosphere of the entire water/radionuclide content of the spent-fuel pool are very small fractions of the PAG levels. A rupture of the spent-fuel pool or the liquid radwaste tanks would result in a total body dose to an average individual via the seafood chain that would be less than the dose from natural background levels. Doses from recreational activities in Humboldt Bay would be negligible

  13. High Tc Josephson Junctions, SQUIDs and magnetometers

    International Nuclear Information System (INIS)

    Clarke, J.

    1991-01-01

    There has recently been considerable progress in the state-of-the-art of high-T c magnetometers based on dc SQUIDs (Superconducting Quantum Interference Devices). This progress is due partly to the development of more manufacturable Josephson junctions, making SQUIDs easier to fabricate, and partly to the development of multiturn flux transformers that convert the high sensitivity of SQUIDs to magnetic flux to a correspondingly high sensitivity to magnetic field. Needless to say, today's high-T c SQUIDs are still considerably less sensitive than their low-T c counterparts, particularly at low frequencies (f) where their level of 1/f noise remains high. Nonetheless, the performance of the high-T c devices has now reached the point where they are adequate for a number of the less demanding applications; furthermore, as we shall see, at least modest improvements in performance are expected in the near future. In this article, the author outlines these various developments. This is far from a comprehensive review of the field, however, and, apart from Sec. 2, he describes largely his own work. He begins in Sec. 2 with an overview of the various types of Josephson junctions that have been investigated, and in Sec. 3, he describes some of the SQUIDs that have been tested, and assess their performance. Section 4 discuss the development of the multilayer structures essential for an interconnect technology, and, in particular, for crossovers and vias. Section 5 shows how this technology enables one to fabricate multiturn flux transformers which, in turn, can be coupled to SQUIDs to make magnetometers. The performance and possible future improvements in these magnetometers are assessed, and some applications mentioned

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

    International Nuclear Information System (INIS)

    Gershenson, M.

    1991-01-01

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

  15. Das Ganze der Natur Alexander von Humboldt und das romantische Forschungsprogramm

    Directory of Open Access Journals (Sweden)

    Kristian Köchy

    2002-10-01

    Full Text Available Article in German, Abstracts in English, German and Spanish. The wholeness of natureAlexander von Humboldt and the romantic research programIt does not seem to be clear whether there is a tight junction between the humboldian science and the romantic research program. But by recognizing the principal aim of Humboldts concept – the representation of nature as a whole – one can see how Humboldts view has been developed in contact with romantic ideas. This investigation analyses Humboldts research program in consideration of its main features and the special relations between science, philosophy of nature, feeling of nature, history and art.

  16. Double-barrier junction based dc SQUID

    NARCIS (Netherlands)

    Bartolomé, M.E.; Brinkman, Alexander; Flokstra, Jakob; Golubov, Alexandre Avraamovitch; Rogalla, Horst

    2000-01-01

    dc SQUIDs based on double-barrier Nb/Al/AlOx/Al/AlOx/Al/Nb junctions (DBSQs) have been fabricated and tested for the first time. The current–voltage curves have been measured at temperatures down to 1.4 K. The critical current, Ic, dependence on the temperature T is partially described by the

  17. One Period of Exploration with the Squid.

    Science.gov (United States)

    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)

  18. Squid Dissection: From Pen to Ink.

    Science.gov (United States)

    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)

  19. The Humboldt High Magnetic Field Center at Berlin

    International Nuclear Information System (INIS)

    Hansel, S; Mueller, H-U; Anh, T T; Richter, B; Rossmann, H; Ortenberg, M von

    2006-01-01

    The Humboldt High Magnetic Field Center is operated by the Chair for Magnetotransport in Solids of the Department of Physics of the Humboldt-Universitaet zu Berlin. It provides DC-magnetic fields up to 20 T, pulsed nondestructive fields of up to 60 T and megagauss fields of up to 331 T using a single-turn coil generator for experimental application focusing on solid state physics. Magneto-optical investigations are carried out in the MIR, NIR and visible wavelength range as well as transport and magnetization experiments. The facility is open to the scientific community and welcomes users within the European project EuroMagNET. The laboratory will be closed in fall 2006 but its experimental facilities will be further accessible to the community in other labs. The single-turn coil generator will be transferred to LNCMP, Toulouse, France, continuing to provide applicable megagauss fields to the European Community

  20. Alexander von Humboldt's perceptions of colonial Spanish America.

    Science.gov (United States)

    Rebok, Sandra

    2009-01-01

    This study presents an in-depth analysis of Alexander von Humboldt's descriptions and critical comments on the colonial society of the different regions he visited during his well-known expedition through the Americas (1799-1804). The criticisms of colonialism that he expressed, reflecting his personal convictions, have already been the focal point of many studies, but Humboldt also was able to offer a more differentiated assessment through comparisons of regional and local traditions and developments. This essay focuses on his personal diaries, which offer many interesting comments on colonial societies. These considerations and impressions made during the expedition are of particular scholarly value since they were not subject to censorship of any kind.

  1. SISTEM OTENTIKASI UNTUK SQUID BERBASIS WEB

    Directory of Open Access Journals (Sweden)

    Febriliyan Samopa

    2006-07-01

    Full Text Available Dalam sebuah jaringan komputer terdapat bermacam-macam tipe user dengan berbagi tingkatan yang berbeda yang juga dibutuhkan perlakuan yang berbeda pada tiap user yang disesuaikan dengan kebutuhan dalam menggunakan akses web, baik berupa http, ftp, gopher, dan lain-lain. Dimana masing-masing user memiliki skala prioritas dalam penggunaan bandwidth, jumlah koneksi maksimum, waktu koneksi, ukuran file maksimum, situs yang tidak boleh diakses dan lain-lain. Tujuan dari penelitian ini adalah membuat sebuah perangkat lunak yang dapat melakukan otentikasi user berdasarkan data konfigurasi yang disimpan dalam basisdata. Selain itu, perangkat lunak yang dibuat dapat memproses request dari client berdasarkan data konfigurasi dengan lebih cepat. Permasalahan yang mucul adalah bagaimana merancang dan membuat suatu perangkat lunak yang dapat melakukan otentikasi user berdasarkan data konfigurasi yang diambil dari basisdata, serta dapat memproses request dari client dengan lebih cepat berdasarkan hak akses yang dimilikinya.Dalam penelitian ini didesain dan diimplementasikan suatu sistem otentikasi user dengan mengambil data user yang tersimpan dalam basisdata MySQL. Disamping itu, dilakukan rekayasa pada beberapa rutin proses yang terdapat dalam squid proxy, supaya proses-proses dapat melakukan pengambilan data konfigurasi yang dialihkan dan disimpan dalam basisdata MySQL. Data konfigurasi ini didasarkan pada pembagian hak akses yang dimiliki oleh masing-masing grup user. Antarmuka berbasis web digunakan sebagai salah satu layanan bagi admin untuk mempermudah pengelolaan dan pengolahan data konfigurasi yang dibuat.Berdasarkan uji coba yang telah dilakukan, terbukti sistem yang dibuat dapat bekerja dengan baik dan tidak melenceng dari fungsi asli sebelum dilakukan perubahan. Bahkan pada penanganan request client yang berukuran besar, kinerja squid mengalami peningkatan dalam hal kecepatan proses yang dibutuhkan. Sebagai contoh, request client pada  file

  2. 78 FR 56944 - Pacific Gas and Electric Company; Humboldt Bay Independent Spent Fuel Storage Installation

    Science.gov (United States)

    2013-09-16

    ... process waste at the Humboldt Bay ISFSI will not significantly affect the quality of the human environment... NUCLEAR REGULATORY COMMISSION [Docket No. 72-27; NRC-2011-0115] Pacific Gas and Electric Company; Humboldt Bay Independent Spent Fuel Storage Installation AGENCY: Nuclear Regulatory Commission. ACTION...

  3. 76 FR 21329 - Humboldt-Toiyabe National Forest; Nevada; Environmental Impact Statement for Geothermal Leasing...

    Science.gov (United States)

    2011-04-15

    ... at 1340 Financial Blvd, Reno, NV 89502, is a cooperating agency for this NEPA analysis. Responsible... Impact Statement for Geothermal Leasing on the Humboldt-Toiyabe National Forest AGENCY: Forest Service, USDA. ACTION: Notice of Intent to prepare an environmental impact statement. SUMMARY: The Humboldt...

  4. Der Briefwechsel zwischen Alexander von Humboldt und Karl Ernst von Baer

    Directory of Open Access Journals (Sweden)

    Thomas Schmuck

    2012-10-01

    Full Text Available Zusammenfassung Der kurze, nicht vollständig erhaltene Briefwechsel zwischen Alexander von Humboldt und Karl Ernst von Baer behandelt sehr verschiedene Themen: Politik, Kriegsgefahr, den Wissenschaftsbetrieb, Auszeichnungen und Tagungen, Embryologie und Cholera. Gemeinsam mit Briefen und Reden ergibt sich dabei ein differenziertes Bild der Beurteilung der beiden Wissenschaftler durch den jeweils anderen. Während Baer sich als Bewunderer Humboldts erweist, erscheint umgekehrt Humboldts Einschätzung Baers als ambivalent. Abstract The short, not completely preserved correspondence between Alexander von Humboldt and Karl Ernst von Baer deals with a wide range of subjects: politics and the danger of war, academic activities, scientific awards and conferences, aspects of embryology and the cholera. Letters to third persons and speeches, together with the correspondence between Humboldt and Baer show a differentiated pattern of mutual appraisal: While Baer always remained an admirer of the elder naturalist, Humboldt’s estimation was characterized by ambivalence.

  5. Image processing for HTS SQUID probe microscope

    International Nuclear Information System (INIS)

    Hayashi, T.; Koetitz, R.; Itozaki, H.; Ishikawa, T.; Kawabe, U.

    2005-01-01

    An HTS SQUID probe microscope has been developed using a high-permeability needle to enable high spatial resolution measurement of samples in air even at room temperature. Image processing techniques have also been developed to improve the magnetic field images obtained from the microscope. Artifacts in the data occur due to electromagnetic interference from electric power lines, line drift and flux trapping. The electromagnetic interference could successfully be removed by eliminating the noise peaks from the power spectrum of fast Fourier transforms of line scans of the image. The drift between lines was removed by interpolating the mean field value of each scan line. Artifacts in line scans occurring due to flux trapping or unexpected noise were removed by the detection of a sharp drift and interpolation using the line data of neighboring lines. Highly detailed magnetic field images were obtained from the HTS SQUID probe microscope by the application of these image processing techniques

  6. Macroscopic quantum tunneling in a dc SQUID

    International Nuclear Information System (INIS)

    Chen, Y.C.

    1986-01-01

    The theory of macroscopic quantum tunneling is applied to a current-biased dc SQUID whose dynamics can be described by a two-dimensional mechanical system with a dissipative environment. Based on the phenomenological model proposed by Caldeira and Leggett, the dissipative environment is represented by a set of harmonic oscillators coupling to the system. After integrating out the environmental degrees of freedom, an effective Euclidean action is found for the two-dimensional system. The action is used to provide the quantum tunneling rate formalism for the dc SQUID. Under certain conditions, the tunneling rate reduces to that of a single current-biased Josephson junction with an adjustable effective critical current

  7. Fundamental characteristics of the QFP measured by the dc SQUID

    International Nuclear Information System (INIS)

    Shimizu, N.; Harada, Y.; Miyamoto, N.; Hosoya, M.; Goto, E.

    1989-01-01

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

  8. Hot electron effect in the dc SQUID

    International Nuclear Information System (INIS)

    Wellstood, F.C.; Clarke, J.; Urbina, C.

    1989-01-01

    The authors have investigated the temperature dependence of the noise in thin-film dc Superconducting Quantum Interference Devices (SQUIDs) down to 20 mK. The white noise measured in the early versions of our SQUIDs did not decrease as the bath temperature was lowered below 150 mK. They have attributed this saturation to a hot electron effect in the thin-film AuCu resistors shunting the Josephson junctions. A theoretical investigation showed that the temperature of the electrons in the shunts should be given by T/sub e/ = (P/ΣΩ)/sup 1/5/, where P is the power dissipated in the shunts, Ω is the shunt volume, and Σ is a proportionality constant. Experimentally, the authors found Σ=(2.4+-0.6)X10/sup 9/WK/sup -5/m/sup -3/. They have redesigned the shunts, adding large thin-film cooling fins, to increase their volume substantially. This technique has reduced T/sub e/ to about 50 mK, with a corresponding improvement in the sensitivity of the SQUIDs

  9. Directly coupled YBCO dc SQUID magnetometers

    International Nuclear Information System (INIS)

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

    1999-01-01

    YBa 2 Cu 3 O 7- x magnetometers have been made on 10mmx10mm MgO substrates by directly coupling the magnetometer pick-up loop to a dc SQUID with narrow strip lines. The dc SQUIDs were made with YBa 2 Cu 3 O 7-x step-edge Josephson junctions. The layout of the magnetometer pick-up loop was chosen as a compromise between maximizing the loop effective area and minimizing the loop inductance. The SQUID was designed to have L S ∼100 pH in order to obtain β L =2I 0 L S /Φ 0 approx.= 1 with the single-junction critical current I 0 ∼10 μA. We have made magnetometers with white noise levels down to 55 fT Hz -1/2 and a 1/f knee at 1 Hz (ac biased). Noise measurements were made on a field-cooled magnetometer. The noise measured at 1 Hz when cooled in 'zero field' was 175 fT Hz -1/2 . When cooled in magnetic fields of B = 50 μT and B = 100 μT we measured the noise at 1 Hz to be 430 fT Hz -1 2 and 1.3 pT Hz -1/2 , respectively. (author)

  10. Recent advancements in the SQUID magnetospinogram system

    Science.gov (United States)

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

    2017-06-01

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

  11. Analysis of Squid Net Fisheries Business Production

    Directory of Open Access Journals (Sweden)

    Herna Octivia Damayanti

    2017-03-01

    Full Text Available Squid net is one of alternatives to replace trawl net in Pati regency. The purposes of the research are 1 to determine the influence factors, 2 to analyze the return to scale, 3 to analyze cost and return.The research location in Juwana Subdistrict particularly Bakaran Kulon, Dukutalit, Bajomulyo and Bendar Villages. The research conducted on October 2015 to June 2016. The number of final samples was 36, while the formulation of management strategies used 15 samples by snowball sampling. Data analysis techniques used 1 Cobb Douglas production function, 2 revenue-cost ratio analysis. The results of the research are 1 significant inputs for production factor are long trip, Solar fuel, the number of crew and lights. 2 the return to scale of squid net bussiness in Juwana subdistrict Pati regency is -0.231 means decreasing to scale. 3 the R/C ratio of scenario II more profitable for squid net crews than  scenario I.

  12. Preliminary report on the PIXE analysis of the squid statoliths

    International Nuclear Information System (INIS)

    Ikeda, Yuzuru; Arai, Nobuaki; Sakamoto, Wataru; Murayama, Tatsuro; Maeda, Kuniko; Yoshida, Koji.

    1996-01-01

    Micro trace elements in the squid statolith, a calcareous stone which acts as a balancer and hearing, was analyzed with Particle Induced X-ray Emission (PIXE) for the Japanese common squid for the first time. Calcium is the main component of the squid statoliths, which means that squid statolith is the pure calcified structure similar to the fish otolith. Beside Ca, Sr was detected with strong dosage, and some other elements as Mn, Fe, Cu, Zn and As were also detected. Possible assumption of intake of microelements to the statoliths and the suitability of PIXE for statoliths analysis are discussed. (author)

  13. Low noise niobium dc SQUID with a planar input coil

    Science.gov (United States)

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

    1983-02-01

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

  14. Low noise niobium dc SQUID with a planar input coil

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-02-15

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

  15. SQUIDs for the readout of metallic magnetic calorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Ferring, Anna; Wegner, Mathias; Fleischmann, Andreas; Gastaldo, Loredana; Kempf, Sebastian; Enss, Christian [Kirchhoff-Institute for Physics, Heidelberg University (Germany)

    2015-07-01

    Superconducting quantum interference devices (SQUIDs) are the devices of choice to read out metallic magnetic calorimeters (MMCs). Here, the temperature change of the detector upon the absorption of an energetic particle is measured as a magnetization change of a paramagnetic temperature sensor that is situated in a weak magnetic field. Driven by the need for devices that allow for the readout of large-scale detector arrays with hundreds or even thousands of individual detectors as well as of single channel detectors with sub-eV energy resolution, we have recently started the development of low-T{sub c} current-sensing SQUIDs. In particular, we are developing cryogenic frequency-domain multiplexers based on non-hysteretic rf-SQUIDs for detector array readout as well as dc-SQUIDs for single channel detector readout. We discuss our SQUID designs and the performance of prototype SQUIDs. We particularly focus on the frequency and temperature dependence of the SQUID noise as well as the reliability of our SQUID fabrication process for Nb/Al-AlO{sub x}/Nb Josephson junctions. Additionally, we demonstrate experimentally that state-of-the-art MMCs can successfully be read out with our current devices. Finally, we discuss different strategies to improve the SQUID and detector performance aiming to reach sub-eV energy resolution for individual detectors as well as for detector arrays.

  16. Antioxidant and antimicrobial activities of squid ink powder

    OpenAIRE

    Fatimah Zaharah, M.Y.; Rabeta, M.S.

    2017-01-01

    Economic development in Malaysia has led to increasing quantity and complexity of generated waste or by-product. The main objective of this study is to investigate the antioxidant and antimicrobial activities of squid ink powder. The squid ink was collected from fresh squid and dried using freeze dryer before it was ground into powder. The yield of squid ink was 22.82% after freeze-drying which was 69.37g in amount. Proximate composition analysis as well as two total antioxidant activity assa...

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

    Science.gov (United States)

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

    2013-02-18

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

  18. Inductance-dependent characteristics of HTS dc-SQUID amplifiers

    International Nuclear Information System (INIS)

    Mitchell, E.E.; Tilbrook, D.L.; Foley, C.P.; MacFarlane, J.

    2002-01-01

    Full text: We have experimentally determined the transfer function V Φ and noise S Φ of several high temperature superconducting (HTS) dc SQUIDs of increasing loop size, while they were operated (without input flux transformer) in a small-signal-amplifier (open-loop) mode. A primary aim of our investigation was to provide reliable inductance data to aid our design of subsequent magnetometer devices. Flux was induced by means of current injection via a well-defined stripline directly into the SQUID loop. The loop size was systematically incremented in a range of otherwise similar SQUIDs. For each SQUID, the ratio between the induced flux and the injection current (which we define as the coupling inductance of the device, L c ) was measured as a function of the injection path length and the SQUID loop dimensions. Both L c and the derived SQUID self-inductance, L sq , were then compared with theoretical values, and contributions due to kinetic inductance and junction inductance were estimated. Correlations between the inductance data and our measured values of transfer function V Φ and noise S Φ were compared with previous results. Guidelines for optimisation of gradiometer SQUIDs were established, and in particular, the importance of achieving a large value transfer function together with a relatively small inductance was demonstrated. The strong influence of an enhanced transfer function was further emphasised when an order-of-magnitude reduction in noise was achieved by subjecting one of our SQUIDs to an in-house 'ion-beam trimming' process

  19. SQUID magnetometry from nanometer to centimeter length scales

    International Nuclear Information System (INIS)

    Hatridge, Michael J.

    2010-01-01

    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.

  20. SQUID magnetometry from nanometer to centimeter length scales

    Energy Technology Data Exchange (ETDEWEB)

    Hatridge, Michael J. [Univ. of California, Berkeley, CA (United States)

    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.

  1. Universal mechanisms of decoherence of qubit states in a SQUID

    Science.gov (United States)

    Kuklov, A. B.; Chudnovsky, E. M.

    2003-03-01

    Fundamental conservation laws mandate parameter-free generic mechanisms of decoherence of quantum oscillations of the superconducting current in a SQUID [1]. The very fact that the current flows with respect to the ion lattice is shown to result in a decoherence via emission of the transverse sound at the oscillation frequency. For SQUIDs larger than the wavelength of the phonons, this effect can significantly limit the quality factor. The decohering effects of the external mechanical and magnetic noise are shown to be proportional to the total magnetic moment of the SQUID, making small SQUIDs less susceptible to the noise than large SQUIDs. Decoherence due to the emission of photons into the open space and in the presence of the metal shielding has been studied as well. Suggestions of experimental setups with low decoherence have been made. [1] E. M. Chudnovsky and A. B. Kuklov, arXiv:cond-mat/0211246.

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

    Directory of Open Access Journals (Sweden)

    Tabatabaei Mahdi

    2015-01-01

    Full Text Available 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.

  3. Current-phase relations and noise in rf biased SQUIDS

    International Nuclear Information System (INIS)

    Jackel, L.D.; Clark, T.D.; Buhrman, R.A.

    1975-01-01

    An investigation was made of the effect of the weak link current-phase relation on noise in rf biased SQUIDs. Non-sinusoidal current-phase relations were observed in various weak links, and these non-sinusoidal relations were correlated with significantly increased intrinsic noise in the SQUID ring. The current-phase relation was also found to affect the amplitude of the rf SQUID ring dissipation. The result of an rf SQUID system noise analysis shows that, due to increased intrinsic noise and reduced ring dissipation, the minimum attainable noise for a SQUID ring having a very non-sinusoidal current-phase relation is considerably greater than for a ring with a sinusoidal relation

  4. Humboldt, un prusiano en la Corte del Rey Carlos IV

    Directory of Open Access Journals (Sweden)

    Puig-Samper, Miguel Ángel

    1999-08-01

    Full Text Available The study of Alejandro de Humboldt's transit through Spain and particularly Madrid, has been one of the forgotten aspects of his historiography. The reasons that would explain the approval by king Charles IV of his trip, involving the minister Mariano de Urquijo and the embassador of Sajonia, baron of Forell, are not sufficiently documented due to the scarce data that Humboldt himself offered in his work and to the absence of any other supporting documents. This work studies the preparation of his American trip and its approval by the Spanish court. It incorporates the Memorandum presented —which was «lost» until now—, the autobiography submitted to the authorities and the references given by Philippe de Forrell. Furthermore, it analyses his relationships with the Spanish scientific community in Madrid and the profile of the team that supported him to achieve his targets.

    El estudio del paso de Alejandro de Humboldt por España y especialmente por Madrid ha sido tradicionalmente uno de los aspectos más olvidados en la historiografía humboldtiana. La repetición de los pocos datos que él mismo ofreció en su obra y la falta de documentos ha hecho insuficiente la explicación de cómo fue aprobado su viaje por el rey Carlos IV, con la intervención del ministro Mariano Luis de Urquijo y del embajador de Sajonia, barón de Forell. En el presente trabajo se estudia la preparación de su viaje americano y su aprobación en la Corte española, aportando la Memoria presentada —abasta ahora «perdida»—, la autobiografía que elevó a las autoridades y el aval de Philippe de Forell. Asimismo se analizan sus relaciones con los científicos españoles en Madrid y el perfil del grupo que le ayudó a conseguir sus objetivos.

  5. Der Briefwechsel zwischen Karl Kreil und Alexander von Humboldt, ein wichtiger Beitrag zur Geschichte des Erdmagnetismus

    Directory of Open Access Journals (Sweden)

    Karin Reich

    2016-11-01

    Full Text Available Abstract The correspondence between Alexander von Humboldt und Karl Kreil was voluminous, it concerned earth magnetism. But only one letter has survived. This letter was written by Kreil on September 3, 1836; one day later Kreil wrote a letter to Carl Friedrich Gauss with nearly the same contents, some sentences are even literally corresponding. Four letters from Kreil to Humboldt were published in the „Annalen der Physik und Chemie“. Some letters were mentioned in the biographical literature dealing with Kreil. These letters show, that the correspondence covered at least the period until 1851 and give information about the intensive relationship between the two scientists. A further interesting source is the library of Humboldt which unfortunately has not survived. The catalogue mentions nine works of Kreil some of them where annotated by Humboldt. This makes it plausible that the contacts even lasted until 1856. Zusammenfassung Die Korrespondenz zwischen Alexander von Humboldt und Karl Kreil war umfangreich und betraf den Erdmagnetismus. Aber heute ist nur noch ein einziger Brief im Original bekannt. Dieser Brief, den Kreil am 3. September 1836 Alexander von Humboldt zukommen ließ, stimmt inhaltlich und teilweise wortwörtlich mit dem Brief überein, den Kreil nur einen Tag später, am 4. September 1836, an Carl Friedrich Gauß schickte. Vier Briefe von Kreil an Humboldt wurden in den „Annalen der Physik und Chemie“ publiziert, eine nicht allzu große Anzahl weiterer Briefe an Humboldt wurde in der biographischen Literatur über Kreil und in Briefen Kreils an Koller und Gauß erwähnt. Aber nicht nur die lückenhafte und bruchstückhaft bekannte Korrespondenz zwischen Humboldt und Kreil, die bis 1851 reicht, gibt Aufschluss über die Beziehungen, sondern von besonderer Bedeutung ist des Weiteren der Bestand an Kreiliana in der Bibliothek Humboldts. Es handelt sich um neun Werke Kreils, das letzte aus dem Jahr 1856. Nachweisbare

  6. Humboldt, Historismus, Humboldteanisierung. Der "Geschichtsschreiber von Amerika", die Massensklaverei und die Globalisierungen der Welt

    Directory of Open Access Journals (Sweden)

    Miachel Zeuske

    2001-10-01

    Full Text Available Article in German, Abstracts in English and Spanish.Humboldt, (German historicism, humboldteanization.The ‘historian of America", mass slavery and the globalisations of the world.This article treats Alexander von Humboldt as an Atlantic intellectual, not only as an european intellectual. The article tries to analize also the "Ensayo político sobre la Isla de Cuba" as a key text of the second globalization ("industrial revolution". Against the background of our knowledge about the reality at the beginnings of the 19th century the article analizes the humboldtian presentation of this reality during his stay in Cuba (1801/1804, confronting it with his "Essay" about Cuba (1826-1831, as well tries to demonstrate the position of Humboldt in the historical thinking. The third part explains the relations of Humboldt to the network of Cuban intellectuals and with some important personalities of the Cuban elite (Arango, Calvo in the development of his work.

  7. Eureka Littoral Cell CRSMP Humboldt Bay Mean Monthly Maximum Water Elevation 2011

    Data.gov (United States)

    California Natural Resource Agency — The Humboldt Bay Shoreline Assessment and LiDAR Analysis was conducted by field mapping the entire shoreline and assigning an unique segment identifier based on a...

  8. NOAA Coastal Services Center orthoimagery for Humboldt, CA, 2009 (NODC Accession 0089055)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of 0.5-meter pixel resolution, four band orthoimages covering the Humboldt Bay area. An orthoimage is remotely sensed image data in which...

  9. Eureka Littoral Cell CRSMP Humboldt Bay Mean Monthly Maximum Water Elevation 2011

    Data.gov (United States)

    California Department of Resources — The Humboldt Bay Shoreline Assessment and LiDAR Analysis was conducted by field mapping the entire shoreline and assigning an unique segment identifier based on a...

  10. Écriture (auto)biographique dans l'Examen critique d'Alexandre de Humboldt

    OpenAIRE

    Julian Drews

    2016-01-01

    Zusammenfassung Der Bezug auf Kolumbus ist ein Gemeinplatz der Humboldtbiographik. Humboldt selbst betont ihn besonders in seinem Examen critique, wo er eine autobiographische Dimension gewinnt. Der Beitrag geht aus literaturwissenschaftlicher Perspektive dem Material und den Formen der Inszenierung nach, mit denen ein Leben über ein anderes dargestellt wird.  Résumé La référence à Colomb est un lieu commun de la biographie humboldtienne. Humboldt lui-même le souligne particulière...

  11. High speed non-latching squid binary ripple counter

    International Nuclear Information System (INIS)

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

    1985-01-01

    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 2 O 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

  12. Composición proximal y propiedades funcionales del surimi liofilizado de Dosidicus gigas “ calamar gigante”

    Directory of Open Access Journals (Sweden)

    Armando Solari - Godiño

    2017-01-01

    Full Text Available El propósito de la investigación fue determinar la composición proximal y propiedades funcionales del surimi liofilizado de calamar gigante ( Dosidicus gigas . Se elaboró surimi a partir de calamar gigante y fue liofilizado hasta obtener surimi en polvo para evaluar sus características y prop iedades funcionales. El contenido de proteínas fue 58,7% y carbohidratos 30,5%. La solubilidad proteica en agua y sal (3% fueron 21,1% y 40,6% respectivamente, siendo estos valores superiores a surimi en polvo de especies comerciales. La capacidad de geli ficación fue 2,4% y la capacidad emulsificante fue 79,9% a una concentración del 1,0%. El color en la escala de Hunter fue L*: 91,5; a*: 0,5; b*:7,0. El surimi en polvo de calamar gigante fue considerado como un polvo proteico funcional debido a su conteni do porcentual proteico, y tuvieron buenas características tecnológicas y de gran potencial en la industria alimentaria .

  13. The sing for Humboldt, for Saussure and for Bakhtin

    Directory of Open Access Journals (Sweden)

    Sebastião Elias Milani

    2015-01-01

    Full Text Available This article shows three of the principal sign conceptions of the studies about language, differences and similarities. The sign is for Humboldt the material representation, or sound-image, of the concept, besides the identity of the articulated language sound; these three parts, sign, concept and sound identity, make the form of the language that is the word. The sign is for Saussure the name of the relation between the signified and the signifier. Saussure proposed the substitution of the terms sound-image and concept, that were full of suggestions and prior conceptualization, to the terms signified and signifier. The sign in Bakhtin is the form of the structure that accomplishes an ideologically sense completed by thought through articulated sound. The meeting between the articulated sound and the concept gives the resulting element of semiosis, so every sign is semiotic.

  14. Eisenmenger ventricular septal defect in a Humboldt penguin (Spheniscus humboldti).

    Science.gov (United States)

    Laughlin, D S; Ialeggio, D M; Trupkiewicz, J G; Sleeper, M M

    2016-09-01

    The Eisenmenger ventricular septal defect is an uncommon type of ventricular septal defect characterised in humans by a traditionally perimembranous ventricular septal defect, anterior deviation (cranioventral deviation in small animal patients) of the muscular outlet septum causing malalignment relative to the remainder of the muscular septum, and overriding of the aortic valve. This anomaly is reported infrequently in human patients and was identified in a 45-day-old Humboldt Penguin, Spheniscus humboldti, with signs of poor growth and a cardiac murmur. This case report describes the findings in this penguin and summarises the anatomy and classification of this cardiac anomaly. To the authors' knowledge this is the first report of an Eisenmenger ventricular septal defect in a veterinary patient. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Antioxidant and antimicrobial activities of squid ink powder

    Directory of Open Access Journals (Sweden)

    Fatimah Zaharah, M.Y.

    2017-10-01

    Full Text Available Economic development in Malaysia has led to increasing quantity and complexity of generated waste or by-product. The main objective of this study is to investigate the antioxidant and antimicrobial activities of squid ink powder. The squid ink was collected from fresh squid and dried using freeze dryer before it was ground into powder. The yield of squid ink was 22.82% after freeze-drying which was 69.37g in amount. Proximate composition analysis as well as two total antioxidant activity assays named 2,2-diphenyl-1-picrylhydrazyl (DPPH assay and Ferric Reducing Antioxidant Power (FRAP assay, and antimicrobial analysis were done on the powdered squid ink. The proximate results of squid ink powder were 4.43 ± 0.29% moisture, 62.46 ± 0.62% protein, 3.96 ± 0.08% fat, and 9.29 ± 0.05% ash. Results of DPPH assay showed that water extraction of squid ink powder has the highest 94.87 ± 4.87%, followed by ethanol 67.57 ± 7.55%, and hexane extract 2.10 ± 1.18%. FRAP assay result presented the same trend with water extraction had the highest value of 929.67 ± 2.31 μmol Fe (II / g of sample extract, followed by ethanol extract 201.00 ± 26.29 μmol Fe (II per gram sample and hexane 79.67 ± 12.66 μmol Fe (II / g of sample extract. Both water and ethanol extract showed antimicrobial properties with inhibition range of 7 to 15 mm, respectively. Fresh squid ink had 1.254 × 103 colony forming unit per gram of sample of microbial content. Squid ink powder had protein as major compound and microbial content was below from standard value of fisheries products as stated in Food Act 1983 and Regulation 1985.

  16. Alexander von Humboldt's Idea of Interconnectedness and its Relationship to Interdisciplinarity and Communication

    Directory of Open Access Journals (Sweden)

    Detlev Doherr

    2015-10-01

    Full Text Available Alexander von Humboldt, a German scientist and explorer of the 19th century, viewed the natural world holistically and described the harmony of nature among the diversity of the physical world as a conjoining between all physical disciplines. He noted in his diary: "Everything is interconnectedness." The main feature of Humboldt's pioneering work was later named "Humboldtian science", meaning the accurate study of interconnected real phenomena in order to find a definite law and a dynamic cause. Following Humboldt's idea of nature, an Internet edition of his works must preserve the author's original intention, retain an awareness of all relevant works, and still adhere to the requirements of scholarly edition. At the present time, however, the highly unconventional form of his publications has undermined the awareness and a comprehensive study of Humboldt's works. Digital libraries should supply dynamic links to sources, maps, images, graphs and relevant texts. New forms of interaction and synthesis between humanistic texts and scientific observation need to be created. Information technology is the only way to do justice to the broad range of visions, descriptions and the idea of nature of Humboldt's legacy. It finally leads to virtual research environments as an adequate concept to redesign our digital archives, not only for Humboldt's documents, but for all interconnected data.

  17. Identität und Differenz Goethes Faust und Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Heinz Krumpel

    2007-04-01

    Full Text Available Article in German, Abstracts in English, Spanish and GermanIn the article “Identity and difference between Goethe`s Faust and Alexander von Humboldt” the issue of how much Faust is contained in Humboldt and in which way Goethe`s Faust has to be related to Alexander von Humboldt is discussed. Here the connection of activity, knowledge and vision as well as the relationship between humans and nature are central to the examination. Goethe and Humboldt were greatly influenced by the enlightenment. Their ideas and visions show us today that modernity is an incomplete project. In Goethe`s Faust the question of the essence of mankind is posed because there is a hint of Faust and Mephisto in each human. With Humboldt those principles acted among other things as a driving force for greater productitivity and the extraction of knowledge. Even though Faust did not fail in his bet with Mephisto, on the other hand he also did not win. Humboldt, however, would have won the bet. Considering the global ecological crisis and regional conflicts today the idea of the relation of Goethe´s Faust and Humboldt has an astonishing relevance.

  18. History and Pre-History of the Alexander von Humboldt Foundation

    Directory of Open Access Journals (Sweden)

    D. Platikanov

    2014-02-01

    Full Text Available In this paper a short review of the history of Alexander von Humboldt Foundation, Bonn - Bad Godesberg, Germany, on the occasion of its 60th anniversary is presented. This outstanding German foundation is actually the third one with the same name. Earlier two other Alexander von Humboldt Foundations consequently existed and they consist its pre-history, which is also shortly reviewed. The establishment of the present Foundation in 1953, its development and growth, its activities, information about the six presidents and five executive directors, as well as the main features, principles and guidelines are considered. During the last 60 years the Alexander von Humboldt Foundation became an important institution for the promotion of international research cooperation, which significantly influences the world science. It supported more than 27700 Humboldt fellows to carry out scientific research in Germany, and they form a large Humboldt family: a world-wide network. Large number Bulgarian Humboldt fellows are among the best scientists in Bulgaria.

  19. A SQUID Bootstrap Circuit with a Large Parameter Tolerance

    International Nuclear Information System (INIS)

    Zhang Guo-Feng; Kong Xiang-Yan; Xie Xiao-Ming; Zhang Yi; Krause Hans-Joachim; Offenhäusser Andreas

    2013-01-01

    The voltage biased (SQUID) bootstrap circuit (SBC) was recently introduced as an effective means to reduce the preamplifier noise contribution. We analyze the tolerances of the SBC noise suppression performance to spreads in SQUID and SBC circuit parameters. It is found that the tolerance to spread mainly caused by the integrated circuit fabrication process could be extended by a one-time adjustable current feedback. A helium-cooled niobium SQUID with a loop inductance of 350 pH is employed to experimentally verify the analysis. From this work, design criteria for fully integrated SBC devices with a high yield can be derived

  20. SQUIDs in thermal detectors of weakly interacting particles

    International Nuclear Information System (INIS)

    Trofimov, V.N.

    1991-01-01

    The application of four different types of SQUID-assisted thermometers for cryogenic thermal detectors of weakly interacting particles is analyzed with two of them for the first time. The classic resistive thermometer is considered as well for the comparison. Original results of testing the detector with working temperature of 1K and thermocouple thermometer with SQUID are given. The conclusion is made that temperature resolution of 10 -10 kHz -1/2 or energy sensitivity of 1-10 eV per 1 kg of detector mass can be achieved when using the SQUID-assisted thermometers. 12 refs.; 7 figs.; 1 tab

  1. Decommissioning of the Humboldt Bay Power Plant, Unit No. 3, Docket No. 50-133, Humboldt County, California

    International Nuclear Information System (INIS)

    1986-04-01

    A draft environmental impact statement (EPA No. 860164D) on plans to decommission unit 3 of the Humboldt Bay reactor in California. The reactor was shutdown in 1976 for seismic modifications after 13 years of operation, but decommissioning proved more economical. The plan calls for retaining spent fuel on the site until a federal repository is available. The utility has established a radiation protection program to limit exposures. Safe storage of the facility is possible for about 30 years, but a fuel-handling or other accident could lead to the release of radionuclides into the atmosphere. A rupture of the spent fuel pool or the liquid radwaste tanks could contaminate the seafood chain, but doses received during recreational use of the bay would be negligible. The Federal Waste Pollution Control Act of 1972 and Nuclear Waste Policy Act of 1982 require the impact statement

  2. rf SQUID system as tunable flux qubit

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, B. [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy)]. E-mail: b.ruggiero@cib.na.cnr.it; Granata, C. [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy); Vettoliere, A. [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy); Rombetto, S. [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy); Russo, R. [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy); Russo, M. [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy); Corato, V. [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-81031 Aversa (Italy); Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy); Silvestrini, P. [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-81031 Aversa (Italy); Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Italy)

    2006-08-21

    We present a fully integrated rf SQUID-based system as flux qubit with a high control of the flux transfer function of the superconducting transformer modulating the coupling between the flux qubit and the readout system. The control of the system is possible by including into the superconducting flux transformer a vertical two-Josephson-junctions interferometer (VJI) in which the Josephson current is precisely modulated from a maximum to zero by a transversal magnetic field parallel to the flux transformer plane. The proposed system can be also used in a more general configuration to control the off-diagonal terms in the Hamiltonian of the flux qubit and to turn on and off the coupling between two or more qubits.

  3. Can understanding squid life-history strategies and recruitment ...

    African Journals Online (AJOL)

    Can understanding squid life-history strategies and recruitment improve management? ... range of potentially limiting conditions in different years, they store genetic diversity and stabilize recruitment in time. ... AJOL African Journals Online.

  4. Negative inductance SQUID qubit operating in a quantum regime

    Science.gov (United States)

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

    2018-04-01

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

  5. Reactive probing of macroscopically quantum mechanical SQUID rings

    International Nuclear Information System (INIS)

    Prance, R.J.; Clark, T.D.; Whiteman, R.; Diggins, J.; Ralph, J.F.; Prance, H.; Spiller, T.P.; Widom, A.; Srivastava, Y.

    1994-01-01

    In this paper we demonstrate that the energy level structure of ultra small capacitance SQUID rings can be probed adiabatically at radio frequency using both dynamical and quasistatic reactive techniques. ((orig.))

  6. Gear Selectivity of a Longfin Squid Bottom Trawl

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Loligo pealeii (longfin inshore squid) co-occurs with Atlantic butterfish (Peprilus triacanthus) throughout the year and discarding in the L. pealeii bottom trawl...

  7. Forecasting chokka squid Loligo vulgaris reynaudii catches and ...

    African Journals Online (AJOL)

    spamer

    2017-11-11

    Nov 11, 2017 ... on ambient water temperature (Augustyn et al. 1992,. A. Oosthuisen, University of ..... from tagged squid and the supply of continuous environ- mental data. ... should a leak develop, and to provide insulation for the electronics.

  8. Dc-SQUID sensor system for multichannel neuromagnetometry

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-03-01

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

  9. Symposium on applications of superconducting quantum interference devices (SQUIDS)

    International Nuclear Information System (INIS)

    1978-01-01

    The abstracts are given of thirteen papers presented at a ''SQUID Symposium'' organized by the Division of Materials Sciences of the U.S. Department of Energy and held March 23--25, 1978, at the University of Virginia. Since SQUID systems have already been utilized in feasibility demonstration in geothermal reservoir exploration, it was recognized that these devices also hold great potential for many other important scientific measurements. Many of these are energy-related, and others include forefront investigations in a diverse group of scientific areas, from biomedical to earthquake monitoring. Research in SQUIDs has advanced so rapidly in recent years that it was felt that a symposium to review the current status and future prospects of the devices would be timely. The abstracts given present an overview of work in this area and hopefully provide an opportunity to increase awareness among basic and applied scientists of the inherent implications of the extreme measurement sensitivity in advanced SQUID systems

  10. Nondestructive evaluation of metallic structures using a SQUID magnetometer

    International Nuclear Information System (INIS)

    Weinstock, H.; Nisenoff, M.

    1985-01-01

    We present one of the first reports of the use of SQUID instrumentation for nondestructive evaluation of electrically conducting and ferromagnetic specimens. We report preliminary experiments on the use of SQUIDs for the detection of defects (such as cracks, holes, weld seams, variations in wall thickness, effects of corrosion, etc.) in the walls of a hollow pipe, and for monitoring the magnetic state of a ferromagnetic sample under stress-strain loading conditions. (orig./BUD)

  11. High-performance DC SQUIDs with submicrometer niobium Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-11-01

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

  12. High-performance dc SQUIDs with submicrometer niobium Josephson junctions

    Science.gov (United States)

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

    1983-11-01

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

  13. High transition-temperature SQUID magnetometers and practical applications

    International Nuclear Information System (INIS)

    Dantsker, E.; Lawrence Berkeley National Lab., CA

    1997-05-01

    The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa 2 Cu 3 O 7-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 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 -1/2 at 1 Hz and 8.5 fT Hz -1/2 at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz -1/2 at 1 Hz and 18 fT Hz -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

  14. High transition-temperature SQUID magnetometers and practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Dantsker, Eugene [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01

    The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa2Cu3O7-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-SrTiO3-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-1/2 at 1 Hz and 8.5 fT Hz-1/2 at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz-1/2 at 1 Hz and 18 fT Hz-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.

  15. Characterization of thermal aging of duplex stainless steel by SQUID

    International Nuclear Information System (INIS)

    Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F.

    1995-01-01

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

  16. Nb nanoSQUIDs for detection of small spin systems

    Energy Technology Data Exchange (ETDEWEB)

    Woelbing, R.; Nagel, J.; Kemmler, M.; Kleiner, R.; Koelle, D. [Physikalisches Institut, Universitaet Tuebingen (Germany); Kieler, O.; Weimann, T.; Kohlmann, J.; Zorin, A. [Fachbereich 2.4 ' ' Quantenelektronik' ' , PTB Braunschweig (Germany); Buchter, A.; Xue, F.; Poggio, M. [Department of Physics, University of Basel (Switzerland); Rueffer, D.; Russo-Averchi, E.; Fontcuberta i Morral, A. [Laboratoire des Materiaux Semiconducteurs, EPF Lausanne (Switzerland); Huber, R.; Berberich, P. [Physik-Department E10, Technische Universitaet Muenchen (Germany); Grundler, D. [Laboratoire des Materiaux Semiconducteurs, EPF Lausanne (Switzerland); Physik-Department E10, Technische Universitaet Muenchen (Germany)

    2013-07-01

    We report on the realization of highly sensitive dc nanoSQUIDs for the investigation of small spin systems in moderate magnetic fields. The Nb SQUIDs are based on normal metal Josephson junctions made of HfTi and patterned by e-beam lithography. We demonstrate stable operation up to B = ± 50 mT without degradation of rms flux noise (S{sub Φ}{sup 1/2} ≤ 280 nΦ{sub 0}/√(Hz)). We also present a multifunctional system combining a Nb nanoSQUID and a low-temperature magnetic force microscope (LTMFM) with a Ni nanotube as a scanning tip. This system allows for magnetization measurements of the Ni tube by using both, LTMFM and SQUID readout. Furthermore, the measurement of magnetic flux Φ vs. position of the particle provides an experimental determination of the coupling factor φ{sub μ} = Φ/μ between SQUID and Ni tube with magnetic moment μ. The results confirm our predictions from numerical simulations, taking into account the SQUID geometry.

  17. Ground-water flow and simulated effects of development in Paradise Valley, a basin tributary to the Humboldt River in Humboldt County, Nevada

    Science.gov (United States)

    Prudic, David E.; Herman, M.E.

    1996-01-01

    A computer model was used to characterize ground-water flow in Paradise Valley, Nevada, and to evaluate probable long-term effects of five hypothetical development scenarios. One finding of the study is that concentrating pumping at the south end of Paradise Valley may increase underflow from the adjacent Humboldt River valley, and might affect flow in the river.

  18. Humboldt der Seefahrer und sein Marinechronometer Ein Beitrag zur Geschichte der Nautik und Meereskunde

    Directory of Open Access Journals (Sweden)

    Gerhard Kortum

    2001-10-01

    Full Text Available Article in German, Abstracts in English, Spanish and German. HUMBOLDT the Navigator and his ChronometerA Contribution to the History of Navigation and OceanographyHUMBOLDT acquired a remarkable precision time-keeper instrument shortly before he left Paris for his Journey to the Neotropics (1799-1804. This chronometer was made by the famous Swiss-French watchmaker Louis BERTHOUD (1753-1813 with the series number 27. It had belonged to "the celebrated BORDA", as HUMBOLDT stated in his "Personal Narrative". Jean Louis BORDA (1733-1799 was a 18th century French navigator, mathematician and cartographer, who invented or improved a number of geomagnetic instruments. HUMBOLDT used this pocket chronometer for his routine astronomic and geomagnetic observations and to fix the longitude of his position while on board a vessel in the Atlantic and Pacific Ocean. Until John "Timekeeper" HARRISON developed his famous "H 4" chronometer in 1773, a strategic invention for a maritime power as Great Britain, the longitude was a major navigational problem. HUMBOLDT, who confessed that he had a "peculiar predelication for the sea", developed great nautical skills, and his findings were much better than those of the pilots. Furthermore he used the chronometer to observe and calculate ocean currents and to improve the geographical coordinates and thus the maps for many places in Latin America. So, beside his thermometer and barometer, the chronometer certainly was a very basic instrument in the state-of-the-art collection of scientific equipment he bought before leaving Europe.

  19. Mineralogical Diversity and Geology of Humboldt Crater Derived Using Moon Mineralogy Mapper Data

    Science.gov (United States)

    Martinot, M.; Besse, S.; Flahaut, J.; Quantin-Nataf, C.; Lozac'h, L.; van Westrenen, W.

    2018-02-01

    Moon Mineralogy Mapper (M3) spectroscopic data and high-resolution imagery data sets were used to study the mineralogy and geology of the 207 km diameter Humboldt crater. Analyses of M3 data, using a custom-made method for M3 spectra continuum removal and spectral parameters calculation, reveal multiple pure crystalline plagioclase detections within the Humboldt crater central peak complex, hinting at its crustal origin. However, olivine, spinel, and glass are observed in the crater walls and rims, suggesting these minerals derive from shallower levels than the plagioclase of the central peak complex. High-calcium pyroxenes are detected in association with volcanic deposits emplaced on the crater's floor. Geologic mapping was performed, and the age of Humboldt crater's units was estimated from crater counts. Results suggest that volcanic activity within this floor-fractured crater spanned over a billion years. The felsic mineralogy of the central peak complex region, which presumably excavated deeper material, and the shallow mafic minerals (olivine and spinel) detected in Humboldt crater walls and rim are not in accordance with the general view of the structure of the lunar crust. Our observations can be explained by the presence of a mafic pluton emplaced in the anorthositic crust prior to the Humboldt-forming impact event. Alternatively, the excavation of Australe basin ejecta could explain the observed mineralogical detections. This highlights the importance of detailed combined mineralogical and geological remote sensing studies to assess the heterogeneity of the lunar crust.

  20. Mineralogical Diversity and Geology of Humboldt Crater Derived Using Moon Mineralogy Mapper Data.

    Science.gov (United States)

    Martinot, M; Besse, S; Flahaut, J; Quantin-Nataf, C; Lozac'h, L; van Westrenen, W

    2018-02-01

    Moon Mineralogy Mapper (M 3 ) spectroscopic data and high-resolution imagery data sets were used to study the mineralogy and geology of the 207 km diameter Humboldt crater. Analyses of M 3 data, using a custom-made method for M 3 spectra continuum removal and spectral parameters calculation, reveal multiple pure crystalline plagioclase detections within the Humboldt crater central peak complex, hinting at its crustal origin. However, olivine, spinel, and glass are observed in the crater walls and rims, suggesting these minerals derive from shallower levels than the plagioclase of the central peak complex. High-calcium pyroxenes are detected in association with volcanic deposits emplaced on the crater's floor. Geologic mapping was performed, and the age of Humboldt crater's units was estimated from crater counts. Results suggest that volcanic activity within this floor-fractured crater spanned over a billion years. The felsic mineralogy of the central peak complex region, which presumably excavated deeper material, and the shallow mafic minerals (olivine and spinel) detected in Humboldt crater walls and rim are not in accordance with the general view of the structure of the lunar crust. Our observations can be explained by the presence of a mafic pluton emplaced in the anorthositic crust prior to the Humboldt-forming impact event. Alternatively, the excavation of Australe basin ejecta could explain the observed mineralogical detections. This highlights the importance of detailed combined mineralogical and geological remote sensing studies to assess the heterogeneity of the lunar crust.

  1. The low fault HTSL-SQUID cooling system. Final report; Stoerarmes HTSL-SQUID-Kuehlsystem. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Binneberg, A.; Spoerl, G.; Buschmann, H.

    1997-03-01

    In the context of the research project, work was done for HTSL-SQUID on (1) the development of a thermo-siphon cooler (low fault and continuously working) and (2) the development of a latent storage cooler (low fault and discontinuously working). Two development versions of the latent storage cooler were followed up, the development of a spherical latent storage cooler and the development of an annular vessel latent storage cooler. A further precondition for the construction of the cooler was the use of split Stirling refrigerators as units producing the cold. The experimental sample was built up with refrigerators which could produce a nominal cooling output of 1.2 W at 80 K. Two samples of the thermo-siphon cooler were built, tested and improved. The second sample was developed further as a demonstration model, introduced at meetings and prepared for testing the cooling of HTSL-SQUIDs. The thermo-siphon cooler can be designed for cooling output up to about 2 W at 80 K and can be used controlled for a temperature range of 90 K to 66 K. (orig./MM) [Deutsch] Im Rahmen des Forschungsvorhabens wurde fuer HTSL-SQUID`s an der (1) Entwicklung eines Thermosiphon-Kuehlers (stoerarm und kontinuierlich arbeitend) und (2) Entwicklung eines Latentspeicher-Kuehlers (stoerfrei und diskontinuierlich arbeitend) gearbeitet. Bei dem Latentspeicher-Kuehler wurden zwei Entwicklungsversionen verfolgt, und zwar Entwicklung eines Kugel-Latentspeicher-Kuehlers und Entwicklung eines Ringgefaess-Latentspeicher-Kuehlers. Eine weitere Praemisse zum Aufbau der Kuehler war der Einsatz von Split-Stirling-Kaeltemaschinen als kaelteerzeugende Baugruppe. Die Versuchsmuster wurden mit Kaeltemaschinen aufgebaut, die eine Nennkuehlleistung von 1,2 W bei 80 K erzeugen konnten. Der Thermosiphon-Kuehler wurde in zwei Musterexemplaren aufgebaut, erprobt und verbessert. Das Zweitmuster wurde als Demonstrator weiterentwickelt, zu Fachtagungen vorgestellt und zur Testung der Kuehlung von HTSL-SQUIDs

  2. Measurements of the dynamic input impedance of a dc SQUID

    International Nuclear Information System (INIS)

    Hilbert, C.; Clarke, J.

    1985-01-01

    The impedance of a circuit coupled magnetically via a mutual inductance M/sub i/ to a dc SQUID of geometric inductance L is modified by the dynamic input impedance of the SQUID, which can be characterized by the flux-to-current transfer function J/sub Phi/approx. =partialJ/partialPhi; J is the current circulating in the SQUID loop and ∫ is the flux applied to the loop. At the same time, the SQUID is modified by the presence of the input circuit in the lumped circuit approximation, one expects its inductance to be reduced to L'(1-α/sub e/ 2 )L, where α/sub e/ is an effective coupling coefficient. Calculations of J/sub Phi/ using an analog simulator are described and presented in the form of a dynamic inductance L and a dynamic resistance R versus bias current I and Phi. Experimental measurements of L and R were made on a planar, thin-film SQUID tightly coupled to a spiral input coil that was connected in series with a capacitor C/sub i/ to form a resonant circuit. Thus, J/sub Phi/ was determined from the change in the resonant frequency and quality factor of this circuit as a function of I and Phi. At low bias currents (low Josephson frequencies) the measured values of L were in reasonable agreement with values simulated for the reduced SQUID, while at higher bias currents (higher Josephson frequencies) the measured values were in better agreement with values simulated for the unscreened SQUID. Similar conclusions were reached in the comparison of the experimental and simulated values of the flux-to-voltage transfer function V/sub Phi/

  3. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    International Nuclear Information System (INIS)

    Heaney, M.B.

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al 2 O 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 x 10 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 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

  4. SQUID use for Geophysics: finding billions of dollars

    Science.gov (United States)

    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.

  5. High-Tc SQUIDs: Noise and applications

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hsiao-Mei [Univ. of Houston, TX (United States)

    2001-08-01

    A major challenge in the design and operation of high transition temperature (Tc ) Superconducting Quantum Interference Devices (SQUIDs) is their potential to exhibit substantially higher levels of noise at low frequency f when exposed to earth’s magnetic field. To investigate this problem, we studied the noise of high-Tc SQUIDs, directly coupled magnetometers and multilayer magnetometers in both static and changing magnetic fields. The directly coupled magnetometer consists of a dc SQUID connected to a large area pickup loop in parallel. The multilayer magnetometer involves a multiturn flux transformer inductively coupled to a dc SQUID on a separate substrate. All the devices are made of thin films of the high-Tc superconductor YBa2Cu3O7-δ, patterned into 4 μm linewidths. After cooling in a magnetic field, the devices showed no increase in 1/f noise for fields up to threshold values well above the earth’s magnetic field. The devices were also cooled in a magnetic field that was subsequently turned off. The 1/f noise of bare SQUIDs was unchanged for fields up to 12 μT. The addition of the flux transformer containing flux dams increased the sensitivity to magnetic field by a factor of 43 while reducing the threshold field only moderately, to 5 μT. This result implies that the multilayer magnetometer can be rotated in the earth’s magnetic field through an angle of up to 26o without increasing the low frequency noise. The results of these studies were incorporated into a 5-channel high-Tc magnetocardiography system involving two first-derivative SQUID gradiometers and three reference SQUIDs. Each planar gradiometer consists of a directly coupled SQUID magnetometer inductively coupled to the smaller coil of an asymmetric, two-loop flux transformer. The reference SQUIDs are patterned into 4 μm lines. The outputs of the five channels were subtracted in software to form a second-derivative gradiometer. Its

  6. SQUIDs De-fluxing Using a Decaying AC Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Matlashov, Andrei Nikolaevich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Semenov, Vasili Kirilovich [State Univ. of New York (SUNY), Plattsburgh, NY (United States); Anderson, Bill [Senior Scientific, LLC, Albuquerque, NM (United States)

    2016-06-08

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

  7. Zwei Briefe auf Guaraní in Alexander von Humboldts Handschrift

    Directory of Open Access Journals (Sweden)

    Manfred Ringmacher

    2014-12-01

    Full Text Available Gegenstand des Aufsatzes von Manfred Ringmacher sind zwei Briefe auf Guaraní in Alexander von Humboldts Handschrift. Die Originale der Abschriften wurden im Jahr 1800 in der ehemals jesuitisch betreuten Indianersiedlung Santa María la Mayor am Río Uruguay geschrieben und an den Vizekönig des spanischen Vizekönigreichs La Plata gesandt. Sie sind mit einer zeitgenössischen spanischen Übersetzung versehen; außerdem hat Alexander von Humboldt in französischer Sprache noch einige Erläuterungen gegeben.

  8. Structural nature of the Humboldt fault zone in northeastern Nemaha County, Kansas

    International Nuclear Information System (INIS)

    Stander, T.W.

    1989-01-01

    The Kansas Geological Survey has conducted a major re-evaluation of the geology and seismicity of Kansas in connection with design criteria for dams, nuclear-power plants, and other earthquake-sensitive structures. Northeast Kansas was chosen as a study area because of the concentration of seismic activity and the stratigraphic evidence for the maximum amount of vertical displacement of the humboldt fault. This study determines the nature of the deformation on the Humboldt fault and resolves its lateral position and total vertical throw in the near-surface

  9. Die Fußnote über Geognosia in Humboldts Florae Fribergensis specimen

    Directory of Open Access Journals (Sweden)

    Herbert Pieper

    2007-04-01

    Full Text Available Article in German, Abstracts in English and GermanHumboldt distinguished between three disciplines dealing with the inquiring of the earth: geognosia, historia telluris, physiografia. In 1793, he used the notion of “Geognosie” for the first time. He explained the notion in a footnote that was reprinted in 1815, 1817, and again in 1845. The paper analyses the meaning attributed by Humboldt to the notion of “Geognosie” and gives a new German translation of the Latin texts of the footnote.

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

    International Nuclear Information System (INIS)

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

    1991-01-01

    This paper reports on the fabrication of hybrid low T c /high T 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 2 insulation layer over YBCO, and 3. selective patterning of niobium and SiO 2 relative to YBCO. All these process steps are pertinent to the eventual use of YBCO thin films in electronic devices

  11. Dipole location using SQUID based measurements: Application to magnetocardiography

    Science.gov (United States)

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

    2012-07-01

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

  12. Application of squids in the Iwate create project

    International Nuclear Information System (INIS)

    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.

    2005-01-01

    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

  13. Scanning high-Tc SQUID imaging system for magnetocardiography

    International Nuclear Information System (INIS)

    Yang, H-C; Wu, T-Y; Horng, H-E; Wu, C-C; Yang, S Y; Liao, S-H; Wu, C-H; Jeng, J T; Chen, J C; Chen, Kuen-Lin; Chen, M J

    2006-01-01

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

  14. Humboldt entre a filosofia da natureza e a ciência moderna / Humboldt between the philosophy of nature and modern science

    Directory of Open Access Journals (Sweden)

    Thiago Brito

    2015-08-01

    Full Text Available This work aims to identify the influence of German thought, above all, the philosophy of nature in Humboldt's “modern science”. He brings from the philosophers the conception of the harmonious totality of nature as an organism to recognize the existence of a connection between the forces of nature and its form captured by intuition. The philosophy of nature exposes the bond between the visible world and the upper world that escapes the senses. Humboldt, however, is not only concerned with the contemplation of nature, but also seeks to measure it, bringing it closer to his eyes to understand its internal connections. The technical and scientific instruments are also an extension of his gaze and his hand. Humboldt want to combine the measurement and quantification with the enjoyment afforded by intellectual intuition in touch with the landscape. The Cosmos, therefore, is presented as a whole to be deciphered through observations and comparisons, but also through an aesthetic perception of natural phenomena.

  15. How Alexander von Humboldt's life story can inspire innovative soil research in developing countries

    Directory of Open Access Journals (Sweden)

    J. Bouma

    2017-09-01

    Full Text Available The pioneering vision of Alexander von Humboldt of science and society of the early 1800s is still highly relevant today. His open mind and urge to make many measurements characterizing the interconnected web of life are crucial ingredients as we now face the worldwide challenge of the UN Sustainable Development Goals. Case studies in the Philippines, Vietnam, Kenya, Niger, and Costa Rica demonstrate, in Alexander's spirit, interaction with stakeholders and attention to unique local conditions, applying modern measurement and modeling methods and allowing inter- and transdisciplinary research approaches. But relations between science and society are increasingly problematic, partly as a result of the information revolution and post-truth, fact-free thinking. Overly regulated and financially restricted scientific communities in so-called developed countries may stifle intellectual creativity. Researchers in developing countries are urged to leapfrog these problems in the spirit of Alexander von Humboldt as they further develop their scientific communities. Six suggestions to the science community are made with particular attention to soil science. (The Humboldt lecture, presented by the 2017 recipient of the Alexander von Humboldt lecture, Johan Bouma, can be accessed at http://client.cntv.at/egu2017/ml1.

  16. 78 FR 49723 - Humboldt-Toiyabe National Forests; Ely Ranger District; Ely Westside Rangeland Project

    Science.gov (United States)

    2013-08-15

    ... Month (AUM) production for the Humboldt National Forest while improving the gap between existing and...: 1. Current Management Alternative: Continue current grazing management. 2. No Grazing Alternative... documents. (Authority: 40 CFR 1501.7 and 1508.22; Forest Service Handbook 1909.15, Section 21) Dated: August...

  17. Mineralogical diversity and geology of Humboldt crater derived using Moon Mineralogy Mapper data

    NARCIS (Netherlands)

    Martinot, M.; Besse, S.; Flahaut, J.; Quantin-Nataf, C.; Lozac'h, L.; van Westrenen, W.

    2018-01-01

    Moon Mineralogy Mapper (M3) spectroscopic data and high-resolution imagery data sets were used to study the mineralogy and geology of the 207 km diameter Humboldt crater. Analyses of M3 data, using a custom-made method for M3 spectra continuum removal and spectral parameters calculation, reveal

  18. On the carbonic acid distributed in the atmosphere, of Alexander Von Humboldt

    International Nuclear Information System (INIS)

    Pelkoswski, Joaquin

    2001-01-01

    Translation that is made of a essay of Alexander Von Humboldt in which describes their own experiences related with the carbon dioxide (denominated carbonic acid in that time) in the atmosphere and in the we can capture the big difficulties around their measurement and their presence in the great gassy cover that surrounds us and it allows us to live

  19. Development and implications of a sediment budget for the upper Elk River watershed, Humboldt County

    Science.gov (United States)

    Lee H. MacDonald; Michael W. Miles; Shane Beach; Nicolas M. Harrison; Matthew R. House; Patrick Belmont; Ken L. Ferrier

    2017-01-01

    A number of watersheds on the North Coast of California have been designated as sediment impaired under the Clean Water Act, including the 112 km2 upper Elk River watershed that flows into Humboldt Bay just south of Eureka. The objectives of this paper are to: 1) briefly explain the geomorphic context and anthropogenic uses of the Elk River...

  20. Fine sediment sources in coastal watersheds with uplifted marine terraces in northwest Humboldt County, California

    Science.gov (United States)

    Stephen Sungnome Madrone; Andrew P. Stubblefield

    2012-01-01

    Erosion in the Mill and Luffenholtz Creek watersheds in Humboldt County, California, with their extensive clay soils, can lead to high turbidity levels in receiving bodies of water, increasing the costs of treating water for domestic water supplies. Detailed road and erosion surveys and monitoring of suspended sediment, discharge, and turbidity levels in Mill Creek (3....

  1. El naturalista Alejando de Humboldt, Cavanilles y Juan Andrés

    Directory of Open Access Journals (Sweden)

    María-Rosario MARTÍ MARCO

    2009-11-01

    Full Text Available RESUMEN: Tras una breve introducción en la que se traza un paralelismo entre el erudito Juan Andrés y el naturalista Alejandro de Humboldt, se presenta una síntesis de la relevancia del viaje científico de Humboldt iniciado en España. Las referencias sobre la figura y trabajo de Humboldt y, en menor medida, sobre Cavanilles en la gran obra total de Andrés demuestran el vigor intelectual de éste, quien subraya muchos de los elementos fundamentales del legado humboldtiano.ABSTRACT: This paper begins with a brief introduction to the similarities between the scholar Juan Andrés and the naturalist Alexander von Humboldt and continues with a summary of the relevance of Humboldt’s scientific expedition which began in Spain. The references to Humboldt’s persona and endeavours, and to a lesser extent to Cavanilles, in all of Andrés’ great works demonstrate the intellectual ability of the author who pinpoints many of the fundamental aspects of Humboldt’s legacy.

  2. Defender of Humanism in the Alienated World--Citrine's Humanistic Journey in "Humboldt's Gift"

    Science.gov (United States)

    Xiang, Fang

    2016-01-01

    The novel "Humboldt's Gift" reveals the dilemma of two intelligentsia in the modern society where consumerism and materialism further aggravates the alienation among people and the culture is degraded into a capital form and is commercialized, so the dignity and even the survival of poets are threatened by this material-centered society.…

  3. How Alexander von Humboldt's life story can inspire innovative soil research in developing countries

    Science.gov (United States)

    Bouma, Johan

    2017-09-01

    The pioneering vision of Alexander von Humboldt of science and society of the early 1800s is still highly relevant today. His open mind and urge to make many measurements characterizing the interconnected web of life are crucial ingredients as we now face the worldwide challenge of the UN Sustainable Development Goals. Case studies in the Philippines, Vietnam, Kenya, Niger, and Costa Rica demonstrate, in Alexander's spirit, interaction with stakeholders and attention to unique local conditions, applying modern measurement and modeling methods and allowing inter- and transdisciplinary research approaches. But relations between science and society are increasingly problematic, partly as a result of the information revolution and post-truth, fact-free thinking. Overly regulated and financially restricted scientific communities in so-called developed countries may stifle intellectual creativity. Researchers in developing countries are urged to leapfrog these problems in the spirit of Alexander von Humboldt as they further develop their scientific communities. Six suggestions to the science community are made with particular attention to soil science. (The Humboldt lecture, presented by the 2017 recipient of the Alexander von Humboldt lecture, Johan Bouma, can be accessed at http://client.cntv.at/egu2017/ml1.)

  4. Himmelsblau. Bemerkungen zum Thema „Farben“ in Humboldts Alterswerk Kosmos. Entwurf einer physischen Weltbeschreibung

    Directory of Open Access Journals (Sweden)

    Petra Werner

    2006-04-01

    Full Text Available Articel in German, Abstracts in English and German.For the greater part of his life, Alexander von Humboldt was interested in colour phenomena which he observed in nature. These observations led him to do research into phenomena such as the blue colour of the sky, enigmatic dust and hail, and the colour of plants. Humboldt corresponded with many scientists about the connection between sunlight and the creation of colours, about coloured shadows, the Blue Cave in Capri, the colour of stars, plants etc. Claude-Louis Berthollet developed a model for the composition of a blue colour (Indigo, a technology which was of great importance to the textile industry.The present paper focuses on Humboldt’s interest in the blue colour of the sky, which he shared with artists, writers and scientists like Johann Wolfgang von Goethe, Christian Gottfried Lichtenberg, Caspar David Friedrich and Horace Bénédict de Saussure. During his travels in South America, Humboldt used Saussure’s cyanometer to determine the intensity of the blue colour of the sky. Later he corresponded about this instrument with his friend François Arago who had invented a cyanometer based on chromatic polarisation. While Humboldt was working on his “Cosmos”, Arago explained to his friend the latest results in physics, especially in polarography. Towards the end of his life, Humboldt corresponded with the painter J. G. Schall and admitted that he had somewhat lost his interest in the physical explanation of the blue colour of the sky.

  5. Progress in Decommissioning the Humboldt Bay Power Plant - 13604

    Energy Technology Data Exchange (ETDEWEB)

    Rod, Kerry [PG and E Utility, Humboldt Bay Power Plant, 1000 King Salmon Ave. Eureka, CA 95503 (United States); Shelanskey, Steven K. [Anata Management Solutions, 5180 South Commerce Dr,, Suite F Murray, UT 84107 (United States); Kristofzski, John [CH2MHILL, 295 Bradley Blvd. Suite 300, Richland WA 99353 (United States)

    2013-07-01

    Decommissioning of the Pacific Gas and Electric (PG and E) Company Humboldt Bay Power Plant (HBPP) Unit 3 nuclear facility has now, after more than three decades of SAFSTOR and initial decommissioning work, transitioned to full-scale decommissioning. Decommissioning activities to date have been well orchestrated and executed in spite of an extremely small work site with space constricted even more by other concurrent on-site major construction projects including the demolition of four fossil units, construction of a new generating station and 60 KV switchyard upgrade. Full-scale decommissioning activities - now transitioning from Plant Systems Removal (PG and E self-perform) to Civil Works Projects (contractor performed) - are proceeding in a safe, timely, and cost effective manner. As a result of the successful decommissioning work to date (approximately fifty percent completed) and the intense planning and preparations for the remaining work, there is a high level of confidence for completion of all HBPP Unit 3 decommissions activities in 2018. Strategic planning and preparations to transition into full-scale decommissioning was carried out in 2008 by a small, highly focused project team. This planning was conducted concurrent with other critical planning requirements such as the loading of spent nuclear fuel into dry storage at the Independent Spent Fuel Storage Installation (ISFSI) finishing December 2008. Over the past four years, 2009 through 2012, the majority of decommissioning work has been installation of site infrastructure and removal of systems and components, known as the Plant System Removal Phase, where work scope was dynamic with significant uncertainty, and it was self-performed by PG and E. As HBPP Decommissioning transitions from the Plant System Removal Phase to the Civil Works Projects Phase, where work scope is well defined, a contracting plan similar to that used for Fossil Decommissioning will be implemented. Award of five major work scopes

  6. Progress in Decommissioning the Humboldt Bay Power Plant - 13604

    International Nuclear Information System (INIS)

    Rod, Kerry; Shelanskey, Steven K.; Kristofzski, John

    2013-01-01

    Decommissioning of the Pacific Gas and Electric (PG and E) Company Humboldt Bay Power Plant (HBPP) Unit 3 nuclear facility has now, after more than three decades of SAFSTOR and initial decommissioning work, transitioned to full-scale decommissioning. Decommissioning activities to date have been well orchestrated and executed in spite of an extremely small work site with space constricted even more by other concurrent on-site major construction projects including the demolition of four fossil units, construction of a new generating station and 60 KV switchyard upgrade. Full-scale decommissioning activities - now transitioning from Plant Systems Removal (PG and E self-perform) to Civil Works Projects (contractor performed) - are proceeding in a safe, timely, and cost effective manner. As a result of the successful decommissioning work to date (approximately fifty percent completed) and the intense planning and preparations for the remaining work, there is a high level of confidence for completion of all HBPP Unit 3 decommissions activities in 2018. Strategic planning and preparations to transition into full-scale decommissioning was carried out in 2008 by a small, highly focused project team. This planning was conducted concurrent with other critical planning requirements such as the loading of spent nuclear fuel into dry storage at the Independent Spent Fuel Storage Installation (ISFSI) finishing December 2008. Over the past four years, 2009 through 2012, the majority of decommissioning work has been installation of site infrastructure and removal of systems and components, known as the Plant System Removal Phase, where work scope was dynamic with significant uncertainty, and it was self-performed by PG and E. As HBPP Decommissioning transitions from the Plant System Removal Phase to the Civil Works Projects Phase, where work scope is well defined, a contracting plan similar to that used for Fossil Decommissioning will be implemented. Award of five major work scopes

  7. Can understanding squid life-history strategies and recruitment ...

    African Journals Online (AJOL)

    Current views of the links between life-history strategies and recruitment processes in fish are contrasted with the pattern emerging for squid. A general perspective is that the roles of space and time are reversed in the two groups, suggesting that management strategies also should differ. The space/time reversal appears to ...

  8. Scanning SQUID susceptometers with sub-micron spatial resolution

    International Nuclear Information System (INIS)

    Kirtley, John R.; Rosenberg, Aaron J.; Palmstrom, Johanna C.; Holland, Connor M.; Moler, Kathryn A.; Paulius, Lisa; Spanton, Eric M.; Schiessl, Daniel; Jermain, Colin L.; Gibbons, Jonathan; Fung, Y.-K.K.; Gibson, Gerald W.; Huber, Martin E.; Ralph, Daniel C.; Ketchen, Mark B.

    2016-01-01

    Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ_0/Hz"1"/"2. This high spatial resolution is accomplished by deep sub-micron feature sizes, well shielded pickup loops fabricated using a planarized process, and a deep etch step that minimizes the spacing between the sample surface and the SQUID pickup loop. We describe the design, modeling, fabrication, and testing of these sensors. Although sub-micron spatial resolution has been achieved previously in scanning SQUID sensors, our sensors not only achieve high spatial resolution but also have integrated modulation coils for flux feedback, integrated field coils for susceptibility measurements, and batch processing. They are therefore a generally applicable tool for imaging sample magnetization, currents, and susceptibilities with higher spatial resolution than previous susceptometers.

  9. The magnapinnidae, a newly discovered family of oceanic Squid ...

    African Journals Online (AJOL)

    A peculiar squid paralarva from Hawaiian waters was described by Young (1991, Bull. mar. Sci. 49(1–2): 162–185), but it could not be assigned to any known family. Two larger juvenile specimens have now been obtained, one collected near the surface in the eastern Pacific Ocean and the other rehydrated from a dried ...

  10. A mass stranding of the squid martialia hyadesi Rochebrune and ...

    African Journals Online (AJOL)

    1997-02-11

    Feb 11, 1997 ... All animals were immature, with females in lower stages of maturity than males. No predatory marine mammals were seen in the area during or after the stranding event. An interpretation of the stranding is presented with reference to historical reports of squid strandings worldwide. Evidence suggests some ...

  11. Review of Magneto cardiography Technology based on SQUID

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. H.; Kwon, H.; Kim, J. M.; Kim, K.; Yu, K. K.; Park, Y. K. [Brain and Cognition Measurement Lab, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2012-04-15

    Electric activity of cardiac muscles generates magnetic fields. Magnetocardiography (or MCG) technology, measuring these magnetic signals, can provide useful information for the diagnosis of heart diseases. It is already about 40 years ago that the first measurement of MCG signals was done by D. Cohen using SQUID (superconducting quantum interference device) sensor inside a magnetically shielded room. In the early period of MCG history, bulky point-contact RF-SQUID was used as the magnetic sensor. Thanks to the development of Nb-based Josephson junction technology in mid 1980s and new design of tightly-coupled DC-SQUID, low-noise SQUID sensors could be developed in late 1980s. In around 1990, several groups developed multi-channel MCG systems and started clinical study. However, it is quite recent years that the true usefulness of MCG was verified in clinical practice, for example, in the diagnosis of coronary artery disease. For the practical MCG system, technical elements of MCG system should be optimized in terms of performance, fabrication cost and operation cost. In this review, development history, technical issue, and future development direction of MCG technology are described.

  12. Scanning SQUID susceptometers with sub-micron spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Kirtley, John R., E-mail: jkirtley@stanford.edu; Rosenberg, Aaron J.; Palmstrom, Johanna C.; Holland, Connor M.; Moler, Kathryn A. [Department of Applied Physics, Stanford University, Stanford, California 94305-4045 (United States); Paulius, Lisa [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Spanton, Eric M. [Department of Physics, Stanford University, Stanford, California 94305-4045 (United States); Schiessl, Daniel [Attocube Systems AG, Königinstraße 11A, 80539 Munich (Germany); Jermain, Colin L.; Gibbons, Jonathan [Department of Physics, Cornell University, Cornell, Ithaca, New York 14853 (United States); Fung, Y.-K.K.; Gibson, Gerald W. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Huber, Martin E. [Department of Physics, University of Colorado Denver, Denver, Colorado 80217-3364 (United States); Ralph, Daniel C. [Department of Physics, Cornell University, Cornell, Ithaca, New York 14853 (United States); Kavli Institute at Cornell, Ithaca, New York 14853 (United States); Ketchen, Mark B. [OcteVue, Hadley, Massachusetts 01035 (United States)

    2016-09-15

    Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ{sub 0}/Hz{sup 1/2}. This high spatial resolution is accomplished by deep sub-micron feature sizes, well shielded pickup loops fabricated using a planarized process, and a deep etch step that minimizes the spacing between the sample surface and the SQUID pickup loop. We describe the design, modeling, fabrication, and testing of these sensors. Although sub-micron spatial resolution has been achieved previously in scanning SQUID sensors, our sensors not only achieve high spatial resolution but also have integrated modulation coils for flux feedback, integrated field coils for susceptibility measurements, and batch processing. They are therefore a generally applicable tool for imaging sample magnetization, currents, and susceptibilities with higher spatial resolution than previous susceptometers.

  13. A contribution to the biology of the ommastrephid squid Martialia ...

    African Journals Online (AJOL)

    Updated knowledge on the distribution and biology of the ommastrephid squid Martialia hyadesi in the South-West Atlantic Ocean is presented. Although the species has an Antarctic circumpolar distribution, its most frequent area of appearance is in the South-West Atlantic, where commercial catches have been made.

  14. Reducing systematic errors in measurements made by a SQUID magnetometer

    International Nuclear Information System (INIS)

    Kiss, L.F.; Kaptás, D.; Balogh, J.

    2014-01-01

    A simple method is described which reduces those systematic errors of a superconducting quantum interference device (SQUID) magnetometer that arise from possible radial displacements of the sample in the second-order gradiometer superconducting pickup coil. By rotating the sample rod (and hence the sample) around its axis into a position where the best fit is obtained to the output voltage of the SQUID as the sample is moved through the pickup coil, the accuracy of measuring magnetic moments can be increased significantly. In the cases of an examined Co 1.9 Fe 1.1 Si Heusler alloy, pure iron and nickel samples, the accuracy could be increased over the value given in the specification of the device. The suggested method is only meaningful if the measurement uncertainty is dominated by systematic errors – radial displacement in particular – and not by instrumental or environmental noise. - Highlights: • A simple method is described which reduces systematic errors of a SQUID. • The errors arise from a radial displacement of the sample in the gradiometer coil. • The procedure is to rotate the sample rod (with the sample) around its axis. • The best fit to the SQUID voltage has to be attained moving the sample through the coil. • The accuracy of measuring magnetic moment can be increased significantly

  15. A method of background noise cancellation for SQUID applications

    International Nuclear Information System (INIS)

    He, D F; Yoshizawa, M

    2003-01-01

    When superconducting quantum inference devices (SQUIDs) operate in low-cost shielding or unshielded environments, the environmental background noise should be reduced to increase the signal-to-noise ratio. In this paper we present a background noise cancellation method based on a spectral subtraction algorithm. We first measure the background noise and estimate the noise spectrum using fast Fourier transform (FFT), then we subtract the spectrum of background noise from that of the observed noisy signal and the signal can be reconstructed by inverse FFT of the subtracted spectrum. With this method, the background noise, especially stationary inferences, can be suppressed well and the signal-to-noise ratio can be increased. Using high-T C radio-frequency SQUID gradiometer and magnetometer, we have measured the magnetic field produced by a watch, which was placed 35 cm under a SQUID. After noise cancellation, the signal-to-noise ratio could be greatly increased. We also used this method to eliminate the vibration noise of a cryocooler SQUID

  16. Flicker (1/f) noise in tunnel junction DC SQUIDS

    International Nuclear Information System (INIS)

    Koch, R.H.; Clarke, J.; Goubau, W.M.; Martinis, J.M.; Pegrum, C.M.; Van Harlingen, D.J.

    1983-01-01

    We have measured the spectral density of the 1/f voltage noise in current-biased resistively shunted Josephson tunnel junctions and dc SQUIDs. A theory in which fluctuations in the temperature give rise to fluctuations in the critical current and hence in the voltage predicts the magnitude of the noise quite accurately for junctions with areas of about 2 x 10 4 μm 2 , but significantly overestimates the noise for junctions with areas of about 6 μm 2 . DC SQUIDs fabricated from these two types of junctions exhibit substantially more 1/f voltage noise than would be predicted from a model in which the noise arises from critical current fluctuations in the junctions. This result was confirmed by an experiment involving two different bias current and flux modulation schemes, which demonstrated that the predominant 1/f voltage noise arises not from critical current fluctuations, but from some unknown source that can be regarded as an apparent 1/f flux noise. Measurements on five different configurations of dc SQUIDs fabricated with thin-film tunnel junctions and with widely varying areas, inductances, and junction capacitances show that the spectral density of the 1/f equivalent flux noise is roughtly constant, within a factor of three of (10 -10 /f)phi 2 0 Hz -1 . It is emphasized that 1/f flux noise may not be the predominant source of 1/f noise in SQUIDS fabricated with other technologies

  17. SQUID developments for the gravitational wave antenna MiniGRAIL

    NARCIS (Netherlands)

    Pleikies, J.; Usenko, O.; Kuit, K.H.; Flokstra, Jakob; de Waard, A.; de Waard, A.; Frossati, G.

    2007-01-01

    We designed two different sensor SQUIDs for the readout of the resonant mass gravitational wave detector MiniGRAIL. Both designs have integrated input inductors in the order of 1.5 muH and are planned for operation in the mK temperature range. Cooling fins were added to the shunt resistors. The

  18. The biomass and ecology of chokka squid Loligo vulgaris reynaudii ...

    African Journals Online (AJOL)

    Migration, stock size and ecology of chokka squid Loligo vulgaris reynaudii off the West Coast of South Africa were studied and their relationship to other regions compared by analysis of distributional, biomass, and size composition, and biological data collected from biannual research cruises from 1983-1987. Biomass ...

  19. spawning grounds for chokka squid Loligo vulgaris reynaudii, using

    African Journals Online (AJOL)

    denise

    Swimming movements in relation to egg beds have been studied using acoustic micro-electronic transmitters implanted in squid and tracked via 3-D radio-linked acoustic positioning telemetry (O'Dor et al. 1996, 1998, Sauer et al. 1997). Most of these methods are either impractical or would be severely limited on the deeper ...

  20. Humboldt, Historismus, Humboldteanisierung. Der "Geschichtsschreiber von Amerika", die Massensklaverei und die Globalisierungen der Welt. Fortsetzung von HiN 3.

    Directory of Open Access Journals (Sweden)

    Michael Zeuske

    2002-04-01

    Full Text Available Article in German, Abstracts in English and Spanish.Humboldt, (German historicism, humboldteanization.The ‘historian of America", mass slavery and the globalisations of the world.This article treats Alexander von Humboldt as an Atlantic intellectual, not only as an european intellectual. The article tries to analize also the "Ensayo político sobre la Isla de Cuba" as a key text of the second globalization ("industrial revolution". Against the background of our knowledge about the reality at the beginnings of the 19th century the article analizes the humboldtian presentation of this reality during his stay in Cuba (1801/1804, confronting it with his "Essay" about Cuba (1826-1831, as well tries to demonstrate the position of Humboldt in the historical thinking. The third part explains the relations of Humboldt to the network of Cuban intellectuals and with some important personalities of the Cuban elite (Arango, Calvo in the development of his work.

  1. Unterwegs zum Weltbewußtsein. Alexander von Humboldts Wissenschaftsverständnis und die Entstehung einer ethisch fundierten Weltanschauung

    Directory of Open Access Journals (Sweden)

    Ottmar Ette

    2000-10-01

    Full Text Available Article in German, Abstracts in English and Spanish. Towards Global Consciousness. Alexander von Humboldt's Conception of Science and the emerging ethical Weltanschauung. In the context of recent reflections upon global ethics (Hans Küng, global democracy (Otfried Höffe and a new cultural situation after the end of the Cold War (Clifford Geertz, Alexander von Humboldt's concept of global consciousness (Weltbewußtsein marks a decisive point in the ungoing process of the construction of a new ethics of globalization. This article tries to show how Humboldt's transdisciplinary and intercultural conception of sience as WorldWideWeb integrates Kant's philosophical visions of global political institutions and formulates a critique of the non-empirical foundations of Hegel's teleological Weltanschauung. From his Visions of Nature and his Personal Narrative to his Cosmos, Humboldt's theory and practice of science help us to find a new ethos and new answers to the contemporary questions of divergent modernities.

  2. Characterisation of micro and nano SQUIDs at variable temperature and magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Koehn, Claudia; Storm, Jan-Hendrik; Bechstein, Sylke; Schurig, Thomas [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany)

    2015-07-01

    SQUIDs are highly suited to investigate the magnetic properties of samples with small dimensions, such as nanoparticles, or to read out nanoelectromechanical systems (NEMS). Due to the small sample size, SQUIDs with dimensions in the μm or nm regime are desirable. These micro or nano SQUIDs should have a low noise and no hysteresis in the current-voltage-characteristic, even when operated in high magnetic fields of up to several 100 mT. To investigate such SQUID, we developed measurement setups which can simulate the measurement conditions of the intended SQUID application. The design and performance of two measurement setups will be shown and compared. One setup uses a dipstick that is immersed in liquid helium and can be evacuated to provide SQUID temperatures between 4.5 K and 10 K. The other one uses an evaporation cryostat so that the temperature can be varied from 2 K to 60 K. Both setups are equipped with coils to enable SQUID operation in variable magnetic field. To minimize noise, the output of the SQUID under test is preamplified by a SQUID series array which is operated at 4.2 K. First results of the characterisation of micro and nano SQUIDs will be presented.

  3. Magnetic shield effect simulation of superconducting film shield covering directly coupled HTS dc-SQUID magnetometer

    International Nuclear Information System (INIS)

    Terauchi, N.; Noguchi, S.; Igarashi, H.

    2011-01-01

    A superconducting film shield over a SQUID ring improves the robustness of the SQUID with respect to magnetic noise. Supercurrent in the SQUID magnetometer and the superconducting film shield were simulated. The superconducting film shield reduces the influence of the external magnetic field on the SQUID ring. An HTS SQUID is a high sensitive magnetic sensor. In recent years, the HTS SQUID is widely used in various applications. In some applications, high robustness with respect to magnetic noise is required to realize stable operation at outside of a magnetic shielding room. The target of this paper is a directly coupled HTS dc-SQUID magnetometer. To enhance the robustness of the SQUID magnetometer, use of a superconducting thin film shield has been proposed. The magnetic field directly penetrating the SQUID ring causes the change of the critical current of Josephson junction, and then the SQUID magnetometer transitions into inoperative state. In order to confirm the magnetic shield effect of the superconducting film shield, electromagnetic field simulation with 3D edge finite element method was performed. To simulate the high temperature superconductor, E-J characteristics and c-axis anisotropy are considered. To evaluate the effect of the superconducting film shield, an external magnetic field which is supposed to be a magnetic noise is applied. From the simulation results, the time transition of the magnetic flux penetrating the SQUID ring is investigated and the effect of the superconducting film shield is confirmed. The amplitude of the magnetic flux penetrating the SQUID ring can be reduced to about one-sixth since the superconducting film shield prevents the magnetic noise from directly penetrating the SQUID ring.

  4. The presentation of the results of Alexander von Humboldt's voyage to Carlos IV

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Puig-Samper

    2016-05-01

    Full Text Available Resumen  Desde nuestras primeras investigaciones sobre la estancia de Alexander von Humboldt en España siempre nos sorprendió la ausencia de una mínima relación posterior del sabio prusiano con la corona española y sus autoridades. Iniciada una nueva investigación, encontramos que efectivamente se produjo el envío de un primer trabajo a Carlos IV desde Roma acompañado de una carta de gratitud por la protección recibida durante su viaje americano y de sumisión a la corona española, que ahora presentamos.   Summary Ever since our first research into Alexander von Humboldt's stay in Spain, the absence of an ensuing relationship between the wise Prussian and the Spanish Crown and Authorities had always surprised us. On starting new research, we found that indeed he sent his first work to Carlos IV from Rome accompanied by a letter of gratitude for the protection he had received during his American trip and submission to the Spanish Crown, which we now present. This first literary fruit of his voyage, which Alexander von Humboldt alluded to in the letter is the first instalment of his work Plantes Équinoxiales, Recueillies au Mexique, dans l’ile de Cuba, dans les provinces de Caracas, de Cumana etc., published in Paris in 1805.   Zusammenfassung Seit unseren ersten Forschungen über den Aufenthalt Alexander von Humboldts in Spanien hat uns das Fehlen einer hieran anschließenden Beziehung des preußischen Wissenschaftlers mit der spanischen Krone und ihren Behörden erstaunt. Im Laufe einer erneuten Aufnahme der Forschung, haben wir nun entdeckt, dass Humboldt in der Tat von Rom aus eine erste Arbeit an Karl IV gesandt hatte, zusammen mit einem Schreiben des Dankes (für den während der amerikanischen Reise erhaltenen Schutz sowie seiner Unterordnung unter die spanische Krone, das wir nun präsentieren. Das erste literarische Ergebnis seiner Reise, auf das Humboldt in diesem Brief verweist, ist der erste Faszikel seines Werkes

  5. Connecting the New World. Nets, mobility and progress in the Age of Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Moritz von Brescius

    2012-12-01

    Full Text Available Zusammenfassung Dieser Artikel untersucht das Verhältnis zwischen den revolutionären technologischen Neuerungen des 19. Jahrhunderts und dem Leben und Wirken Alexander von Humboldts (1769-1859. Dabei wird gefragt, wie Humboldt versuchte, die neuen und sprichwörtlich bahnbrechenden Kommunikations- und Transporttechnologien seiner Zeit zu nutzen, um den amerikanischen Kontinent in globale kommerzielle und kulturelle Austauschprozesse zu integrieren. Jüngere Forschungen zu Humboldts amerikanischer Expedition (1799-1804 haben behauptet, dass seine Beschreibungen Südamerikas den Kontinent für zahlreiche „transformative interventions“ (Pratt von Seiten europäischer Kapitalisten und Investoren zugänglich gemacht hätten. Diese Studien haben jedoch nicht analysiert, aus welchen Motiven heraus Humboldt diese Eingriffe in die Natur unterstützte. Darüber hinaus wurde nicht der zentralen Frage nachgegangen, welche Rolle diese Projekte in Humboldts eigener Auffassung über die Kräfte des gesellschaftlichen Fortschritts gespielt haben. Um Humboldts Unterstützung für tiefgreifende Eingriffe in die Natur Amerikas nachvollziehen zu können, analysiert dieser Artikel zunächst, welche Rolle der „Geodeterminismus“ und die Fortschrittstheorien der Aufklärung in seinem Verständnis von zivilisatorischer Entwicklung spielten. Dabei sollen solche Beispiele menschlicher Interventionen in die Natur Amerikas untersucht werden, die Humboldt selbst aktiv förderte – nicht zuletzt, da sie geeignet schienen, „natürliche“ Barrieren für gesellschaftliche Austauschprozesse zu beseitigen. Dies waren vor allem die Nutzung von Dampfschiffen, elektrischer Telegrafie, Eisenbahnen und großangelegten Kanalprojekten, deren gebündelte Effekte zu einer signifikanten Beschleunigung von Welthandel und Kommunikationsprozessen führten. Diese zeitgenössischen Innovationen sollen mit den vier Motiven „Netz“, „Mobilität“, „Fortschritt“ und

  6. SQUIDs in biomagnetism: a roadmap towards improved healthcare

    Science.gov (United States)

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

    2016-11-01

    Globally, the demand for improved health care delivery while managing escalating costs is a major challenge. Measuring the biomagnetic fields that emanate from the human brain already impacts the treatment of epilepsy, brain tumours and other brain disorders. This roadmap explores how superconducting technologies are poised to impact health care. Biomagnetism is the study of magnetic fields of biological origin. Biomagnetic fields are typically very weak, often in the femtotesla range, making their measurement challenging. The earliest in vivo human measurements were made with room-temperature coils. In 1963, Baule and McFee (1963 Am. Heart J. 55 95-6) reported the magnetic field produced by electric currents in the heart (‘magnetocardiography’), and in 1968, Cohen (1968 Science 161 784-6) described the magnetic field generated by alpha-rhythm currents in the brain (‘magnetoencephalography’). Subsequently, in 1970, Cohen et al (1970 Appl. Phys. Lett. 16 278-80) reported the recording of a magnetocardiogram using a Superconducting QUantum Interference Device (SQUID). Just two years later, in 1972, Cohen (1972 Science 175 664-6) described the use of a SQUID in magnetoencephalography. These last two papers set the scene for applications of SQUIDs in biomagnetism, the subject of this roadmap. The SQUID is a combination of two fundamental properties of superconductors. The first is flux quantization—the fact that the magnetic flux Φ in a closed superconducting loop is quantized in units of the magnetic flux quantum, Φ0 ≡ h/2e, ≈ 2.07 × 10-15 Tm2 (Deaver and Fairbank 1961 Phys. Rev. Lett. 7 43-6, Doll R and Näbauer M 1961 Phys. Rev. Lett. 7 51-2). Here, h is the Planck constant and e the elementary charge. The second property is the Josephson effect, predicted in 1962 by Josephson (1962 Phys. Lett. 1 251-3) and observed by Anderson and Rowell (1963 Phys. Rev. Lett. 10 230-2) in 1963. The Josephson junction consists of two weakly coupled superconductors

  7. Robot-arm-based mobile HTS SQUID system for NDE of structures

    Energy Technology Data Exchange (ETDEWEB)

    Yotsugi, K; Hatsukade, Y; Tanaka, S [Department of Ecological Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, Aichi 441-8580 (Japan)], E-mail: hatukade@eco.tut.ac.jp

    2008-02-01

    A robot-arm-based mobile HTS SQUID system was developed for NDE of fixed targets. To realize the system, active magnetic shielding technique using fluxgate as reference sensor for ambient field was applied to a cryocooler-based HTS SQUID gradiometer that was mounted on commercial robot-arm. In this technique, ambient field noise and pulse noise of 550 nT from robot were measured by the fluxgate near the SQUID, and then the fluxgate output was negatively fed back to generate compensation field around the SQUID and fluxgate. The noise from robot was reduced by a factor of about 20 and the shielding technique enabled the HTS SQUID to move in unshielded environment by the robot-arm without flux-trapping or unlocking at 10 mm/s. System noise measurement and inspection of hidden cracks in multi-layer composite-metal structure were demonstrated using the mobile SQUID-NDE system.

  8. Design consideration for dc SQUIDs fabricated in deep sub-micron technology

    International Nuclear Information System (INIS)

    Ketchen, M.B.

    1991-01-01

    Design rules for scaling dc SQUID junctions to optimize SQUID performance have been well known for over a decade, and verified down to the sub-micron regime. Practical SQUIDs having well coupled input coils of usable inductance have generally been fabricated at the 2-5 μm level of lithography. Other technologies, silicon in particular, are now routinely practiced at the 0.5 μm level of lithography with impressive demonstrations at the 0.1-0.25 μm level not uncommon. In this paper the implications of applying such fabrication capability to advance dc SQUID technology are explored. In particular the issues of scaling practical dc SQUIDs down to the 0.1-0.25 μm regime are examined, using as a prototype design the basic washer SQUID with a spiral input coil

  9. Two-stage SQUID systems and transducers development for MiniGRAIL

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  10. A SQUID gradiometer module with wire-wound pickup antenna and integrated voltage feedback circuit

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Guofeng [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich (FZJ), D-52425 Juelich (Germany); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yi, E-mail: y.zhang@fz-juelich.de [Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich (FZJ), D-52425 Juelich (Germany); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); Zhang Shulin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); Krause, Hans-Joachim [Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich (FZJ), D-52425 Juelich (Germany); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); and others

    2012-10-15

    The performance of the direct readout schemes for dc SQUID, Additional Positive Feedback (APF), noise cancellation (NC) and SQUID bootstrap circuit (SBC), have been studied in conjunction with planar SQUID magnetometers. In this paper, we examine the NC technique applied to a niobium SQUID gradiometer module with an Nb wire-wound antenna connecting to a dual-loop SQUID chip with an integrated voltage feedback circuit for suppression of the preamplifier noise contribution. The sensitivity of the SQUID gradiometer module is measured to be about 1 fT/(cm {radical}Hz) in the white noise range in a magnetically shielded room. Using such gradiometer, both MCG and MEG signals are recorded.

  11. From Alexander von Humboldt to Frederic Edwin Church: Voyages of Scientific Exploration and Artistic Creativity

    Directory of Open Access Journals (Sweden)

    Frank Baron

    2005-04-01

    Full Text Available Article in English, Abstracts in Spanish, German and English.Stephen Jay Gould wrote recently that “when Church began to paint his great canvases, Alexander von Humboldt may well have been the world’s most famous and influential intellectual.” Humboldt’s influence in the case of the landscape artist Church is especially interesting. If we examine the precise relationship between the German explorer and his American admirer, we gain an insight into how Humboldt transformed Church’s life and signaled a new phase in the career of the artist. Church retraced Humboldt’s travels in Ecuador and in Mexico. If we compare the texts available to Church and the comparison of Church’s paintings and the texts and images of Humboldt’s works we can arrive at new perspectives on Humboldt’s extraordinary influence on American landscape painting in the nineteenth century.

  12. Evaluation of nuclear facility decommissioning projects. Status report. Humboldt Bay Power Plant Unit 3, SAFSTOR decommissioning

    International Nuclear Information System (INIS)

    Baumann, B.L.; Haffner, D.R.; Miller, R.L.; Scotti, K.S.

    1986-06-01

    This document explains the purpose of the US Nuclear Regulatory Commission's (NRC) Evaluation of Nuclear Facility Decommissioning Projects (ENFDP) program and summarizes information concerning the decommissioning of the Humboldt Bay Power Plant (HBPP) Unit 3 facility. Preparations to put this facility into a custodial safe storage (SAFSTOR) mode are currently scheduled for completion by June 30, 1986. This report gives the status of activities as of June 1985. A final summary report will be issued after completion of this SAFSTOR decommissioning activity. Information included in this status report has been collected from the facility decommissioning plan, environmental report, and other sources made available by the licensee. This data has been placed in a computerized data base system which permits data manipulation and summarization. A description of the computer reports that can be generated by the decommissioning data system (DDS) for Humboldt Bay and samples of those reports are included in this document

  13. Alexander von Humboldt: The American Hemisphere and TransArea Studies

    Directory of Open Access Journals (Sweden)

    Ottmar Ette

    2014-06-01

    Full Text Available From the very first landing in a bounteous tropical world, European wonderment in the face of so many marvels naturally possessed a dimension that strived for knowledge and tried to conjoin a new world with old and antiquarian knowledge in a very reductionist fashion. Is Alexander von Humboldt therefore merely a new, a “second Columbus,” as he was so often described in the further course of the history of his reception? Does he simply repeat the gestures and res gestae for which the great discoverers had already set the example and in a way even predetermined? Are Humboldt and Bonpland thus caught in the trap of the perception of the other in occidental culture that enters the gray area of colonial expansion and an imperial(ist view?

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

    Energy Technology Data Exchange (ETDEWEB)

    Schönau, T.; Schmelz, M.; Stolz, R.; Anders, S.; Linzen, S.; Meyer, H.-G. [Department of Quantum Detection, Leibniz Institute of Photonic Technology, Jena 07745 (Germany); Zakosarenko, V.; Meyer, M. [Supracon AG, An der Lehmgrube 11, Jena 07751 (Germany)

    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.

  15. The squid-Vibrio symbioses: from demes to genes.

    Science.gov (United States)

    Kimbell, Jennifer R; McFall-Ngai, Margaret J

    2003-04-01

    The monospecific light organ association between the Hawaiian sepiolid squid Euprymna scolopes and the marine luminous bacterium Vibrio fischeri has been used as a model for the study of the most common type of coevolved animal-bacterial interaction; i.e., the association of Gram-negative bacteria with the extracellular apical surfaces of polarized epithelia. Analysis of the squid-vibrio symbiosis has ranged from characterizations of the harvesting mechanisms by which the host ensures colonization by the appropriate symbiont to identification of bacteria-induced changes in host gene expression that accompany the establishment and maintenance of the relationship. Studies of this model have been enhanced by extensive collaboration with microbiologists, who are able to manipulate the genetics of the bacterial symbiont. The results of our studies have indicated that initiation and persistence of the association requires a complex, reciprocal molecular dialogue between these two phylogenetically distant partners.

  16. On-site detection of packaged squid freshness

    Science.gov (United States)

    Ahmad, Noor Azizah; Heng, Lee Yook; Salam, Faridah; Hanifah, Sharina Abu

    2018-04-01

    The development of indicator label for detection of total volatile basic nitrogen (TVB-N) is described. Dye extract from edible plants containing anthocyanins was immobilized onto iota-carrageenan as polymer matrix. TVB-N detection worked based on pH increase as the basic deterioration volatile amines generated in the package headspace. Results showed that the indicator label has changed color from blue to green after 12 hours of storage at ambient conditions. The TVB-N value was 38.9648 mg /100 g which is exceeded of acceptability level for seafood products. The pH value of squid flesh has also increased during storage. The colour values of L * and a * negative increases while b* negative decrease with increasing storage time. The indicator label is potentially used as freshness indicator for squid at ambient conditions.

  17. Magnetic evaluation of a solar panel using HTS-SQUID

    Energy Technology Data Exchange (ETDEWEB)

    Kiwa, Toshihiko, E-mail: kiwa@okayama-u.ac.jp; Fukudome, Yohei; Miyazaki, Shingo; Saari, Mohd Mawardi; Sakai, Kenji; Tsukada, Keiji

    2013-11-15

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

  18. Magnetic evaluation of a solar panel using HTS-SQUID

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  19. Temporal variation of seston biomarkers within the Humboldt Current System off northern Chile (21

    Directory of Open Access Journals (Sweden)

    Sergio Rossi

    2012-06-01

    Full Text Available Proportions and concentrations of seston fatty acids, n-alkanes and glycerol dialkyl glycerol tetraethers (GDGTs were used to assess potential differences in the phytoplankton composition and food quality in the Humboldt Current System (winter 2006, summer 2007 and winter 2007 in surface, oxycline, intermediate and bottom water layers. The zone below the intermediate depth was poorer in fatty acids (minimum 15 – maximum 117mg fatty acids L

  20. Radiological dose to man through the marine pathway from reactor operations at Humboldt Bay, California

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Robison, W.L.; Harrison, F.L.

    1976-01-01

    Source-strength measurements and environmental samples taken at the Humboldt Bay Nuclear Reactor site near Eureka, California, since mid-1971 were used to evaluate the potential dose to man resulting from an aquatic release of radioactivity from the reactor. In this report, we provide an evaluation of individual and population dose through the marine pathways during 1972 and 1973 computed by the methods recommended by the U.S. Nuclear Regulatory Commission

  1. Humboldt Bay Wetlands Review and Baylands Analysis. Volume I. Summary and Findings.

    Science.gov (United States)

    1980-08-01

    the best and most compatible economic, environmental, and social uses of the Humboldt Bay area. Such data includes inven- tories of uses and conditions... personal communication). Since 1973, 22 general permits have been granted by the Harbor District; of these, there were 3 for submarine pipeline/cable...other water charateristics determine the type and abundance. Distribution Water habitats are distributed throughout the study area. Deep and shallow

  2. Humboldt y Bonpland en Popayán. Una visita histórica

    Directory of Open Access Journals (Sweden)

    Gerardo Paz Otero

    1968-01-01

    Full Text Available El barón von Humboldt y el médico francés Aimé Bonpland fueron huéspedes muy gratos del Popayán colonial durante su histórico viaje de estudios; especial interés tenían los ilustres visitantes en conocer a Caldas y enterarse de sus observaciones cosmológicas ya ponderadas por Mutis.

  3. Coherent arrays of planar dc-SQUIDS based on thin-film Josephson microbridges

    International Nuclear Information System (INIS)

    Hansen, J.B.

    1982-01-01

    Phase-locking and voltage-locking in systems consisting of two planar dc-SQUIDs located close together in the same superconducting film have been investigated. The locking strength was found to be strongly dependent on the fluxoid state of both SQUIDs. A simple model for the inductive coupling between two such dc-SQUIDs is presented and the prediction of the model is compared with the experimental results. (Auth.)

  4. Absolute calibration and beam background of the Squid Polarimeter

    International Nuclear Information System (INIS)

    Blaskiewicz, M.M.; Cameron, P.R.; Shea, T.J.

    1996-01-01

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

  5. Symplectin evolved from multiple duplications in bioluminescent squid

    DEFF Research Database (Denmark)

    Francis, Warren R.; Christianson, Lynne M.; Haddock, Steven H.D.

    2017-01-01

    The squid Sthenoteuthis oualaniensis, formerly Symplectoteuthis oualaniensis, generates light using the luciferin coelenterazine and a unique enzyme, symplectin. Genetic information is limited for bioluminescent cephalopod species, so many proteins, including symplectin, occur in public databases...... functioning is conserved across essentially all members of the protein family, even those unlikely to be used for bioluminescence. Conversely, active site residues involved in pantetheinase catalysis are also conserved across essentially all of these proteins, suggesting that symplectin may have multiple...

  6. Antibacterial Activity of Melanin from Cuttlefish and Squid Ink

    OpenAIRE

    Yuspihana Fitrial; Iin Khusnul Khotimah

    2017-01-01

    Marine environment comprises of many organism which are known to posses bioactive compound as a common means of self-defense or for the protection of eggs and embryos. Class Cephalopods (such as squidand cuttlefish) are notable for their defences, such as jetting escape movements, changes in colouration, toxic venom and inking.This study aims to compare the antibacterial activity of melanin from cuttlefish ink (Sepia sp.) with squid ink (Loligo sp.) against E. coli. Extraction and purificatio...

  7. Detecting damage in steel with scanning SQUID microscopy

    International Nuclear Information System (INIS)

    Lee, Tae-Kyu; Clatterbuck, D.M.; Morris, J.W. Jr.; Shaw, T.J.; Lee, Seungkyun; Clarke, John

    2002-01-01

    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

  8. Detecting damage in steel with scanning SQUID microscopy

    International Nuclear Information System (INIS)

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

    2001-01-01

    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

  9. Contrasting patterns of selection between MHC I and II across populations of Humboldt and Magellanic penguins.

    Science.gov (United States)

    Sallaberry-Pincheira, Nicole; González-Acuña, Daniel; Padilla, Pamela; Dantas, Gisele P M; Luna-Jorquera, Guillermo; Frere, Esteban; Valdés-Velásquez, Armando; Vianna, Juliana A

    2016-10-01

    The evolutionary and adaptive potential of populations or species facing an emerging infectious disease depends on their genetic diversity in genes, such as the major histocompatibility complex (MHC). In birds, MHC class I deals predominantly with intracellular infections (e.g., viruses) and MHC class II with extracellular infections (e.g., bacteria). Therefore, patterns of MHC I and II diversity may differ between species and across populations of species depending on the relative effect of local and global environmental selective pressures, genetic drift, and gene flow. We hypothesize that high gene flow among populations of Humboldt and Magellanic penguins limits local adaptation in MHC I and MHC II, and signatures of selection differ between markers, locations, and species. We evaluated the MHC I and II diversity using 454 next-generation sequencing of 100 Humboldt and 75 Magellanic penguins from seven different breeding colonies. Higher genetic diversity was observed in MHC I than MHC II for both species, explained by more than one MHC I loci identified. Large population sizes, high gene flow, and/or similar selection pressures maintain diversity but limit local adaptation in MHC I. A pattern of isolation by distance was observed for MHC II for Humboldt penguin suggesting local adaptation, mainly on the northernmost studied locality. Furthermore, trans-species alleles were found due to a recent speciation for the genus or convergent evolution. High MHC I and MHC II gene diversity described is extremely advantageous for the long-term survival of the species.

  10. Hydrogeochemical studies of historical mining areas in the Humboldt River basin and adjacent areas, northern Nevada

    Science.gov (United States)

    Nash, J. Thomas

    2005-01-01

    The study area comprises the Humboldt River Basin and adjacent areas, with emphasis on mining areas relatively close to the Humboldt River. The basin comprises about 16,840 mi2 or 10,800,000 acres. The mineral resources of the Humboldt Basin have been investigated by many scientists over the past 100 years, but only recently has our knowledge of regional geology and mine geology been applied to the understanding and evaluation of mining effects on water and environmental quality. The investigations reported here apply some of the techniques and perspectives developed in the Abandoned Mine Lands Initiative (AMLI) of the U.S. Geological Survey (USGS), a program of integrated geological-hydrological-biological-chemical studies underway in the Upper Animas River watershed in Colorado and the Boulder River watershed in, Montana. The goal of my studies of sites and districts is to determine the character of mining-related contamination that is actively or potentially a threat to water quality and to estimate the potential for natural attenuation of that contamination. These geology-based studies and recommendations differ in matters of emphasis and data collection from the biology-based assessments that are the cornerstone of environmental regulations.

  11. SQUID sensor application for small metallic particle detection

    International Nuclear Information System (INIS)

    Tanaka, Saburo; Hatsukade, Yoshimi; Ohtani, Takeyoshi; Suzuki, Shuichi

    2009-01-01

    High-Tc superconducting quantum interference device (SQUID) is an ultra-sensitive magnetic sensor. Since the performance of the SQUID is improved and stabilized, now it is ready for application. One strong candidate for application is a detection system of magnetic foreign matters in industrial products or beverages. There is a possibility that ultra-small metallic foreign matter has been accidentally mixed with industrial products such as lithium ion batteries. If this happens, the manufacturer of the product suffers a great loss recalling products. The outer dimension of metallic particles less than 100 μm cannot be detected by an X-ray imaging, which is commonly used for the inspection. Ionization of the material is also a big issue for beverages in the case of the X-ray imaging. Therefore a highly sensitive and safety detection system for small foreign matters is required. We developed detection systems based on high-Tc SQUID with a high-performance magnetic shield. We could successfully measure small iron particles of 100 μm on a belt conveyer and stainless steel balls of 300 μm in water. These detection levels were hard to be achieved by a conventional X-ray detection or other methods

  12. Simulation and optimization of a dc SQUID with finite capacitance

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, V.J.; Schrijner, P.; Llurba, R.

    1984-02-01

    This paper deals with the calculations of the noise an the optimization of the energy resolution of a dc SQUID with finite junction capacitance. Up to now noise calculations of dc SQUIDs were performed using a model without parasitic capacitances across the Josephson junctions. As the capacitances limit the performance of the SQUID, for a good optimization one must take them into account. The model consists of two coupled nonlinear second-order differential equations. The equations are very suitable for simulation with an analog circuit. We implemented the model on a hybrid computer. The noise spectrum from the model is calculated with a fast Fourier transform. A calculation of the energy resolution for one set of parameters takes about 6 min of computer time. Detailed results of the optimization are given for products of inductance and temperature of LT = 1.2 and 5 nHK. Within a range of ..beta.. and ..beta../sub c/ between 1 and 2, which is optimum, the energy resolution is nearly independent of these variables. In this region the energy resolution is near the value calculated without parasitic capacitances. Results of the optimized energy resolution are given as a function of LT between 1.2 and 10 nHK.

  13. Simulation and optimization of a dc SQUID with finite capacitance

    Science.gov (United States)

    de Waal, V. J.; Schrijner, P.; Llurba, R.

    1984-02-01

    This paper deals with the calculations of the noise and the optimization of the energy resolution of a dc SQUID with finite junction capacitance. Up to now noise calculations of dc SQUIDs were performed using a model without parasitic capacitances across the Josephson junctions. As the capacitances limit the performance of the SQUID, for a good optimization one must take them into account. The model consists of two coupled nonlinear second-order differential equations. The equations are very suitable for simulation with an analog circuit. We implemented the model on a hybrid computer. The noise spectrum from the model is calculated with a fast Fourier transform. A calculation of the energy resolution for one set of parameters takes about 6 min of computer time. Detailed results of the optimization are given for products of inductance and temperature of LT=1.2 and 5 nH K. Within a range of β and β c between 1 and 2, which is optimum, the energy resolution is nearly independent of these variables. In this region the energy resolution is near the value calculated without parasitic capacitances. Results of the optimized energy resolution are given as a function of LT between 1.2 and 10 mH K.

  14. Transfer of 60Co from midwater squid to sperm whales

    International Nuclear Information System (INIS)

    Umezu, Takeshi; Minamisako, Yoko; Ebihara, Hiroshi; Watanabe, Hiroshi.

    1984-01-01

    Sperm whales are notable squid-eaters. They feed mainly on medium to large-sized cephalopods at midwater levels and defecate near the surface. This suggests the existence of an upward transport of 60 Co by sperm whales from the mesopelagic zone (150-1,200m). To elucidate this squid-whale route for this artificial radionuclide, 60 Co content was determined in squid and in predator whales captured by commercial whaling. In the Cephalopoda livers 60 Co levels of 30-500 mBq kg -1 wet were found and in the viscera of Odontoceti (toothed whales) 15-40 mBq kg -1 wet. About 0.3% of 60 Co ingested was estimated to be retained in a 23-year-old male sperm whale. In the livers of Bryde's whales, 60 Co levels of 40-80 mBq kg -1 wet were detected, but not in euphausiids and sardines, their possible prey. The level of Co in sperm whales was nearly the same as in Bryde's whales. Specific radioactivity 60 Co/ 59 Co in mBq μg -1 was several times higher in sperm whale (1.1-1.6) than in cephalopods (0.19-0.77). Eating prey with a high content of 60 Co in the 1960's may have contributed to the present body burden in sperm whales with a long-life span. However, the origin of 60 Co in Bryde's whales is unknown. (author)

  15. Thermoelectric SQUID method for the detection of segregations

    Science.gov (United States)

    Hinken, Johann H.; Tavrin, Yury

    2000-05-01

    Aero engine turbine discs are most critical parts. Material inhomogeneities can cause disc fractures during the flight with fatal air disasters. Nondestructive testing (NDT) of the discs in various machining steps is necessary and performed as well as possible. Conventional NDT methods, however, like eddy current testing and ultrasonic testing have unacceptable limits. For example, subsurface segregations often cannot be detected directly but only indirectly in such cases when cracks already have developed from them. This may be too late. A new NDT method, which we call the Thermoelectric SQUID Method, has been developed. It allows for the detection of metallic inclusions within non-ferromagnetic metallic base material. This paper describes the results of a feasibility study on aero engine turbine discs made from Inconel® 718. These contained segregations that had been detected before by anodic etching. With the Thermoelectric SQUID Method, these segregations were detected again, and further segregations below the surfaces have been found, which had not been detected before. For this new NDT method the disc material is quasi-transparent. The Thermoelectric SQUID Method is also useful to detect distributed and localized inhomogeneities in pure metals like niobium sheets for particle accelerators.

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

    International Nuclear Information System (INIS)

    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

  17. SQUID-based noise thermometer for sub-Millikelvin refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Marco; Beyer, Joern; Klemm, Monique [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany); Alivaliollahi, Sassan; Barthelmess, Henry [Magnicon GmbH, Barkhausenweg 11, 22339 Hamburg (Germany)

    2015-07-01

    The magnetic field fluctuation thermometer (MFFT) is a high-accuracy SQUID-based noise thermometer suitable for sub-Kelvin thermometry. A highly sensitive low-Tc SQUID magnetometer detects inductively the magnetic field fluctuation above a metal surface. The fluctuations are generated by the thermal activated noise currents inside the metal body that is thermally anchored to the temperature stage to be measured. The spectral shape is independent of temperature as the electrical conductivity is constant and the geometry is fixed. The magnetic noise power spectral amplitudes at any frequencies are directly proportional to temperature. Hence, only one reference measurement at a known temperature is required for calibration. A complete MFFT thermometer system for the temperature range of ca. 4 K down to <10 mK is commercially available. We have now developed an integrated MFFT with an extended range of operation down to <1 mK. For this purpose the sensitivity of the SQUID sensor has been increased, the metal body geometry modified and the magnetic shielding of the MFFT module improved. These modifications make it possible to obtain a thermometer noise temperature of <10 μK. We discuss the rationale for our MFFT configuration and present numerical simulations and experimental results.

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

    Science.gov (United States)

    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.

  19. The future of coastal upwelling in the Humboldt current from model projections

    Science.gov (United States)

    Oyarzún, Damián; Brierley, Chris M.

    2018-03-01

    The Humboldt coastal upwelling system in the eastern South Pacific ocean is one of the most productive marine ecosystems in the world. A weakening of the upwelling activity could lead to severe ecological impacts. As coastal upwelling in eastern boundary systems is mainly driven by wind stress, most studies so far have analysed wind patterns change through the 20th and 21st Centuries in order to understand and project the phenomenon under specific forcing scenarios. Mixed results have been reported, and analyses from General Circulation Models have suggested even contradictory trends of wind stress for the Humboldt system. In this study, we analyse the ocean upwelling directly in 13 models contributing to phase 5 of the Coupled Model Intercomparison Project (CMIP5) in both the historical simulations and an extreme climate change scenario (RCP8.5). The upwelling is represented by the upward ocean mass flux, a newly-included variable that represents the vertical water transport. Additionally, wind stress, ocean stratification, Ekman layer depth and thermocline depth were also analysed to explore their interactions with coastal upwelling throughout the period studied. The seasonal cycle of coastal upwelling differs between the Northern and Southern Humboldt areas. At lower latitudes, the upwelling season spans most of the autumn, winter and spring. However, in the Southern Humboldt area the upwelling season takes place in spring and the summertime with downwelling activity in winter. This persists throughout the Historical and RCP8.5 simulations. For both the Northern and Southern Humboldt areas an increasing wind stress is projected. However, different trends of upwelling intensity are observed away from the sea surface. Whereas wind stress will continue controlling the decadal variability of coastal upwelling on the whole ocean column analysed (surface to 300 m depth), an increasing disconnect with upwelling intensity is projected below 100 m depth throughout the 21

  20. Political Essay on the Kingdom of New Spain: Humboldt and the history of Mexico

    Directory of Open Access Journals (Sweden)

    Luiz Estevam O. Fernandes

    2014-08-01

    Full Text Available Abstract In this paper we discuss how Alexander von Humboldt conceived a past to New Spain in his Political Essay on New Spain (1811 and how this text was, in turn, appropriated by the Mexican historiography during the 19th century. In order to do so, we analyze how the Prussian drew from American sources, particularly from the text of the Jesuit Francisco Javier Clavijero, written shortly before. We also study Humboldt’s conceptions of text and of history, highlighting the place of the indigenous in the composition of his reasoning. Finally, we give examples of how the Mexican nationalist historiography read and reinterpreted the Political Essay. Resumen En este artículo se discute cómo Alexander von Humboldt concibió un pasado a la Nueva España en su Ensayo político sobre el reino de la Nueva España (1811 y cómo este texto, a su vez, fue apropiado por la historiografía mexicana durante el siglo XIX. Para ello, se analiza cómo el prusiano se ha valido de fuentes americanas, sobre todo a partir del texto del jesuita Francisco Javier Clavijero, escrito poco antes. También estudiamos las concepciones de texto y de la historia de Humboldt, destacando el lugar de los indígenas en la composición de su razonamiento. Por último, damos ejemplos de cómo la historiografía nacionalista mexicana leyó y reinterpretó el Ensayo político. Résumé Cet article explique comment Alexander von Humboldt a conçu une passé pour la Nouvelle-Espagne dans son Essai politique sur le royaume de la Nouvelle-Espagne (1811 et la façon que ce texte, à son tour, a été approprié par l’historiographie mexicaine au cours du XIXe siècle. Ainsi, nous analysons comment le prussien a utilisé des sources américaines, en particulier le texte du jésuite Francisco Javier Clavijero, écrit un peu de temps avant. Nous étudions également les conceptions de texte et de l’histoire de Humboldt, en soulignant la place des indigènes dans la composition de son

  1. 76 FR 68642 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Science.gov (United States)

    2011-11-07

    ... update to essential fish habitat designations for all life stages of mackerel, longfin squid, Illex squid... issued a mackerel permit may not fish for, possess, or land more than 20,000 lb (9.08 mt) of mackerel per trip, and that, during any closure that occurs after June 1, vessels may not fish for, possess, or land...

  2. Hallar e inventar a un público. Nuevos proyectos editoriales acerca de la obra de Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Ottmar Ette

    2008-10-01

    Full Text Available Article in español, abstracts in englisch, español and german.In Latin America, Alexander von Humboldt was and is known as one of the most famous historic and literary figures; in his own country, though, the acquaintance with his texts has until the 80s been reduced to groups of specialized scholars. Yet, for a couple of years, a growing interest in the works of Humboldt can be noticed, based on numerous new editions, which have been published since. Among others, these are the new edition of the Relation historique (1991, the editions of the „Humboldt Project“ (2004-2006 as part of the „Andere Bibliothek“, as well as current projects on German editions concerning Asie Centrale and the Examen critique.

  3. Jade aus Amerika und weitere Grünsteinobjekte von Alexander von Humboldt aus dem Berliner Mineralienkabinett

    Directory of Open Access Journals (Sweden)

    Renate Nöller

    2002-04-01

    Full Text Available Article in German, Abstracts in English, Spanish and German.Alexander von Humboldt sent samples of minerals from America not only for scientific or economic purposes. We also find carved pieces made out of green stone material known as Jade, that has been culturally very important in Mesoamerica. In Europe these green stone objects have been treated differently. The Jade-Celt and the Sun-Disc - known as “Humboldt-Axt” and “Humboldt-Scheibe” - both lost during the second world war, had gained great interest, whereas a small head-pendant - made out of Jade has been totally forgotten. The samples reflect the understanding of their worth in distinct cultural contexts.

  4. Noise characteristics of a dc SQUID with a resistively shunted inductance

    International Nuclear Information System (INIS)

    Enpuku, K.; Muta, T.; Yoshida, K.; Irie, F.

    1985-01-01

    Noise characteristics of a dc SQUID with an inductance shunted by a damping resistance are studied numerically. It is shown that the damping resistance improves considerably the resolution of the SQUID in the case of large β, where β = 2LI 0 /Phi 0 , I 0 is a critical current, L is a loop inductance and Phi 0 is the flux quantum. The energy resolutions for β = 4 and β = 10 are only about 2 and 4 times larger than that for β = 1, respectively. Furthermore, the ranges of both the bias current and the external flux, where good resolution is obtained, become very wide compared with the conventional SQUID. Therefore, the SQUID with the damping resistance can be used for large β (or L) without the significant degradation of the resolution, and will much improve the coupling properties between the SQUID and the input circuitry. The numerical simulation results are also compared with analytical ones, and a reasonable agreement is obtained

  5. Correlation between fluxgate and SQUID magnetometer data sets for geomagnetic storms

    Directory of Open Access Journals (Sweden)

    Matladi Thabang

    2014-01-01

    Full Text Available There has always been a need to monitor the near Earth's magnetic field, as this monitoring provides understanding and possible predictions of Space Weather events such as geomagnetic storms. Conventional magnetometers such as fluxgates have been used for decades for Space Weather research. The use of highly sensitive magnetometers such as Superconducting QUantum Interference Devices (SQUIDs, promise to give more insight into Space Weather. SQUIDs are relatively recent types of magnetometers that exploit the superconductive effects of flux quantization and Josephson tunneling to measure magnetic flux. SQUIDs have a very broad bandwidth compared to most conventional magnetometers and can measure magnetic flux as low as a few femtotesla. Since SQUIDs have never been used in Space Weather research, unshielded, it is necessary to investigate if they can be reliable Space Weather instruments. The validation is performed by comparing the frequency content of the SQUID and fluxgate magnetometers, as reported by Phiri.

  6. Low-frequency flux noise in YBCO dc SQUIDs cooled in static magnetic fields

    International Nuclear Information System (INIS)

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

    1999-01-01

    The low-frequency flux noise in bicrystal and step-edge YBa 2 Cu 3 O x dc SQUIDs has been investigated. The width, w, of the superconducting strips forming the SQUID frame was varied from 4 to 42 μm. The SQUIDs were cooled in static magnetic fields up to 150 μT. Two types of low-frequency noise dominated, namely 1/f-like noise and random telegraph noise giving a Lorentzian frequency spectrum. The 1/f noise performance of the w = 4, 6 and 7 μm SQUIDs was almost identical, while the SQUIDs with w = 22 and 42 μm showed an order of magnitude higher noise level. Our analysis of the data suggests an exponential increase of the 1/f noise versus the cooling field, exhibiting a characteristic magnetic field around 40 μT. (author)

  7. Robotic 3D SQUID imaging system for practical nondestructive evaluation applications

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  8. Temperature dependence of the effective sensing area of high-Tc dc SQUIDs

    International Nuclear Information System (INIS)

    Brake, H.J.M. ter; Aarnink, W.A.M.; Bosch, P.J. van den; Hilgenkamp, J.W.M.; Flokstra, J.; Rogalla, H.

    1997-01-01

    The effective sensing area of a high-T c dc SQUID depends on temperature. As a consequence, fluctuations in the operating temperature result in apparent magnetic field noise if the SQUID is placed in a background magnetic field. An analysis of this effect for two SQUID types, the square-washer 'Ketchen' type and the inductively shunted type, is performed. For magnetocardiography, the temperature fluctuations (peak to peak) of the latter SQUID type should be below w 0.3 mK at 77 K, and below 2 mK at 55 K, with an earth's field suppression of 40 dB. For the square-washer SQUID the requirements are about 8 times less stringent. (author)

  9. Evaluación de la toxicidad a dosis repetidas (90 días) por vía oral del concentrado de proteína de pota (Dosidicus gigas), en ratas Sprague dawley

    OpenAIRE

    Rojas Hurtado, Daniel Percy

    2009-01-01

    Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Tecnología de Alimentos El potencial tóxico de un concentrado de proteína de calamar gigante (Dosidicus gigas) fue evaluado mediante el estudio de toxicidad de dosis repetidas a 90 días en ratas Sprague Dawley de ambos sexos. Los métodos empleados fueron los descritos por las normas OECD (1998). Se administró por vía oral la dosis de 500, 1000 y 2000 mg/kg/día durante 13 semanas. Se evaluaron los signos tóxicos y peso...

  10. Issues relating to airborne applications of HTS SQUIDs

    CERN Document Server

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

    2002-01-01

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

  11. Quantum versus thermally excited fluxoid transitions in a SQUID ring

    International Nuclear Information System (INIS)

    Kurkijaervi, J.

    1980-01-01

    The possibility of quantum tunneling as a mechanism for fluxoid transitions in a SQUID ring is carefully considered neglecting, however, dissipation arising from the quasiparticle current. The tunneling rates are compared with the thermally excited transition rates. The type of experiment Jackel et al. carried out in order to observe the thermal process is analyzed for observing the quantum tunneling. We find the expected result that the temperature at which the quantum process should begin to dominate depends essentially on ω 0 = 1/√LC of the ring. If an underdamped junction with C -13 F can be made the quantum tunneling temperature range should be easy to attain. (orig.)

  12. 3D Inversion of SQUID Magnetic Tensor Data

    DEFF Research Database (Denmark)

    Zhdanov, Michael; Cai, Hongzhu; Wilson, Glenn

    2012-01-01

    Developments in SQUID-based technology have enabled direct measurement of magnetic tensor data for geophysical exploration. For quantitative interpretation, we introduce 3D regularized inversion for magnetic tensor data. For mineral exploration-scale targets, our model studies show that magnetic...... tensor data have significantly improved resolution compared to magnetic vector data for the same model. We present a case study for the 3D regularized inversion of magnetic tensor data acquired over a magnetite skarn at Tallawang, Australia. The results obtained from our 3D regularized inversion agree...

  13. Issues relating to airborne applications of HTS SQUIDs

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  14. Thermal activation and macroscopic quantum tunneling in a DC SQUID

    International Nuclear Information System (INIS)

    Sharifi, F.; Gavilano, J.L.; VanHarlingen, D.J.

    1989-01-01

    The authors report measurements of the transition rate from metastable minima in the two-dimensional 1 of a dc SQUID as a function of applied flux temperature. The authors observe a crossover from energy-activated escape to macroscopic quantum tunneling at a critical temperature. The macroscopic quantum tunneling rate is substantially reduced by damping, and also broadens the crossover region. Most interestingly, the authors observe thermal rates that are suppressed from those predicted by the two-dimensional thermal activation model. The authors discuss possible explanations for this based on the interaction of the macroscopic degree of freedom in the device and energy level effects

  15. Alexander von Humboldt brachte Guano nach Europa - mit ungeahnten globalen Folgen

    Directory of Open Access Journals (Sweden)

    Bärbel Rott

    2016-05-01

    Full Text Available Zusammenfassung Die vorliegende Abhandlung beschäftigt sich mit einem bisher wenig beachteten Aspekt von Humboldts Amerikanischer Reise (1799─1804. Während seine Studien der Pflanzen- und Tierwelt bis heute große Aufmerksamkeit genießen, wird Humboldts Beitrag zu der Entwicklung der modernen Landwirtschaft wenig beachtet. Während seines Aufenthalts in Lima erhielt er Proben von Guano, Vogelmist von den Chincha-Inseln vor der peruanischen Küste. Einige Proben, die er von dieser Reise zurückbrachte, wurden von Wissenschaftlern in Frankreich und Deutschland untersucht. Die Analysenergebnisse zeigten außerordentlich hohe Gehalte an Pflanzennährstoffen, insbesondere Stickstoff und Phosphor. In den folgenden Jahrzehnten wurde Guano zu einem bedeutsamen Düngemittel und Auslöser eines Booms in Europa und Peru. Die Auswirkungen dieser Entwicklung sind bis heute sichtbar und werden hier unter besonderer Beachtung von Phosphor beschrieben. Abstract One aspect of Humboldt’s travel to South America (1799─1804 received little attention. The fascination of his studies of the South American flora and fauna is unbroken to the present day. Yet Humboldt’s contribution to modern agriculture remains almost unnoticed. During his stay in Lima Humboldt received samples of guano, a mixture of bird droppings from the Chincha Islands off the Peruvian coast, which he took to Europe and had analyzed by the most famous chemists in France and Germany. The results showed outstanding fertilizing effects, in particular due to the high content of nitrogen and phosphorus. The ensuing boom starting from the 1840s influenced agriculture in Europe and the economy of Peru seriously. Some aspects of this historical development may give an idea of the ensuing change not only in agriculture. Résumé Il y a un aspect du voyage de Alexander von Humboldt en Amérique du Sud (1799─1804 qui jusqu’à présent a été peu considéré. Ses études de la flore at le da

  16. Lo público y lo privado en los escritos de Alexander Von Humboldt sobre Cuba

    Directory of Open Access Journals (Sweden)

    Rebok, Sandra

    2004-12-01

    Full Text Available This study seeks to collect the comments and judgements that Humboldt makes about Cuba and evaluate their character. The resulting analysis and interpretation will be undertaken on two different levels: One refers to the information that can be found in his unofficial works, which means the letters Humboldt sent during or shortly after of his visits to Cuba, as well as the diaries he used during his expedition. The other is based on the official works, which include his travel description, his famous Essay on Cuba and his autobiographical text written in 1804. Constrasting these descriptions, we will compare the evaluations of this Prussian traveller elaborated in the moment he visited the island, with the works he wrote 22 years after his return to Europe.

    Este trabajo tiene el objeto de recopilar los comentarios y juicios que hace Humboldt sobre Cuba y valorar su carácter. El análisis e interpretación que resultará de ello se realiza en dos niveles distintos: uno se refiere a las informaciones que se encuentran en escritos no oficiales, es decir, en las cartas que Humboldt envió durante o poco tiempo después de sus visitas a Cuba, y en los diarios que utilizó a lo largo de su expedición. El otro se fundamenta en los escritos oficiales, que comprenden su narración del viaje, el famoso Ensayo sobre Cuba y la memoria autobiográfica escrita en 1804. Mediante el contraste de estas descripciones se pretende comparar las apreciaciones de este viajero prusiano elaboradas en el preciso momento que visita la isla, cotejándolas con las obras que redactó 22 años después de su vuelta a Europa. Este trabajo tiene el objeto de recopilar los comentarios y juicios que hace Humboldt sobre Cuba y valorar su carácter. El análisis e interpretación que resultará de ello se realiza en dos niveles distintos: uno se refiere a las informaciones que se encuentran en escritos no oficiales, es decir, en las cartas que Humboldt envi

  17. Flux-coherent series SQUID array magnetometers operating above 77 K with superior white flux noise than single-SQUIDs at 4.2 K

    Science.gov (United States)

    Chesca, Boris; John, Daniel; Mellor, Christopher J.

    2015-10-01

    A very promising direction to improve the sensitivity of magnetometers based on superconducting quantum interference devices (SQUIDs) is to build a series-array of N non-interacting SQUIDs operating flux-coherently, because in this case their voltage modulation depth, ΔV, linearly scales with N whereas the white flux noise SΦ1/2 decreases as 1/N1/2. Here, we report the realization of both these improvements in an advanced layout of very large SQUID arrays made of YBa2Cu3O7. Specially designed with large area narrow flux focusers for increased field sensitivity and improved flux-coherency, our arrays have extremely low values for SΦ1/2 between (0.25 and 0.44) μΦ0/Hz1/2 for temperatures in the range (77-83) K. In this respect, they outperform niobium/aluminium trilayer technology-based single-SQUIDs operating at 4.2 K. Moreover, with values for ΔV and transimpedance in the range of (10-17) mV and (0.3-2.5) kΩ, respectively, a direct connection to a low-noise room temperature amplifier is allowed, while matching for such readout is simplified and the available bandwidth is greatly increased. These landmark performances suggest such series SQUID arrays are ideal candidates to replace single-SQUIDs operating at 4.2 K in many applications.

  18. Draft Environmental Statement for decommissioning Humboldt Bay Power Plant, Unit No. 3 (Docket No. 50-133)

    International Nuclear Information System (INIS)

    1986-04-01

    This Draft Environmental Statement (DES) contains th assessment of the environmental impact associated with decommissioning the Humboldt Bay Power Plant Unit 3 located 4 miles southwest of the city of Eureka, Humboldt County, California. This DES is prepared pursuant to the National Environmental Policy Act of 1969 (NEPA) and Title 10 of the Code of Federal Regulations, Part 51, as amended, of the Nuclear Regulatory Commission regulations. The proposed decommissioning would involve safe storage of the facility for about 30 years, after which the residual radioactivity would be removed so that the facility would be at levels of radioactivity acceptable for release of the facility to unrestricted access. 26 refs

  19. Revolution and Exploration: the English Translations of Rousseau and Humboldt by Helen Maria Williams

    Directory of Open Access Journals (Sweden)

    Paula Yurss Lasanta

    2017-12-01

    Full Text Available British author Helen Maria Williams (1759-1827 was a well-known figure in the eighteenth century literary circles, whose work was praised by Elizabeth Montagu, Samuel Johnson, Dorothy and William Wordsworth, Mary Wollstonecraft, Hester Piozzi or Alexander von Humboldt.  In her early poems  Edwin and Eltruda (1782, An Ode to the Peace (1783 and Peru (1784, Williams starts to reveal her political tendencies by appealing to strong empathic feelings as a key to social and political transformation. As a result of her interest in politics, she travelled to France in 1790 and published her most acclaimed work Letters from France (1790. However, the rest of her production has received little critical attention by modern scholars, who have overlooked her involvement in translation. Williams’ only extant novel, Julia (1790 is in fact a creative translation of Rousseau’s Julie ou La Nouvelle Héloïse (1761, in which Williams includes poems that evidence her interest in revolutionary politics. Four years later, she translated Bernardin de Saint Pierre’s Paul et Virginie, while she was imprisoned in Paris. While translating novels was regarded as a respectable exercise for women writers, Williams challenges gender assumptions by translating Researches (1814 and the seven volumes of Personal Narrative (1814-1829, which had been produced by one of the most influential eighteenth century scientists, Alexander von Humboldt. This article interrogates how Williams makes use of translation to access areas of knowledge traditionally restricted to men, such as philosophy, politics and science. For this purpose, I will focus on her translations of the work of two leading intellectual figures of the eighteenth century,  Rousseau and Von Humboldt.

  20. The evolution of seabirds in the Humboldt Current: new clues from the Pliocene of Central Chile.

    Directory of Open Access Journals (Sweden)

    Martín Chávez Hoffmeister

    Full Text Available During the last decade, new Neogene fossil assemblages from South America have revealed important clues about the evolution of seabird faunas in one of the major upwelling systems of the world: the Humboldt Current. However, most of this record comes from arid Northern Chile and Southern Peru and, in consequence, our knowledge of the evolutionary history of seabirds in the temperate transitional zone is negligible. A new Late Pliocene assemblage of fossil birds from the coastal locality of Horcon in Central Chile offers a unique opportunity to fill this gap.Isolated bones of a medium-sized penguin are the most abundant bird remains. Morphological and cladistic analyses reveal that these specimens represent a new species of crested penguin, Eudyptes calauina sp. nov. Eudyptes is a penguin genus that inhabit temperate and subantarctic regions and currently absent in central Chile. Additionally, a partial skeleton of a small species of cormorant and a partial tarsometatarsus of a sooty shearwater have been identified.The Horcon fossils suggest the existence of a mixed avifauna in central Chile during the Pliocene in concordance with the latitudinal thermal gradient. This resembles the current assemblages from the transitional zone, with the presence of species shared with Northern Chile and Southern Peru and a previously unrecorded penguin currently absent from the Humboldt System but present in the Magellanic region. Comparison of Pliocene seabird diversity across the Pacific coast of South America shows that the Horcon avifauna represents a distinctive assemblage linking the living faunas with the Late Miocene ones. A comparison with the fossil record near the Benguela Current (west coast of southern Africa suggests that the thermic gradient could play an important role in the preservation of a higher diversity of cold/temperate seabirds in the Humboldt Current.

  1. A Case of endoscopic retrieval of a long bamboo stick from a Humboldt penguin (Spheniscus humboldti).

    Science.gov (United States)

    Jung, Woo-Sung; Ko, Minho; Cho, Hyun Kee; Kang, Byung-Jae; Choi, Jung Hoon; Chung, Jin-Young

    2017-02-28

    An eighteen-month-old female Humboldt penguin (Spheniscus humboldti) that was 50 cm in length and 4.5 kg in weight was presented with anorexia and vomiting. The hematological and blood biochemical profiles revealed no remarkable findings, and no Salmonella, Shigella or Vibrio spp. were isolated from the fecal culture. However, radiographic imaging revealed a long linear foreign body presenting from the lower esophagus to the stomach. To retrieve this foreign body, flexible endoscopic extraction was performed using flexible rat tooth grasping forceps. A long bamboo stick (29 × 1 cm) was removed from the stomach, and the penguin fully recovered.

  2. "Die Toten reiten schnelle." Literarische Zitate in Briefen von und an Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Ingo Schwarz

    2007-04-01

    Full Text Available Article in GermanAbstract in English and GermanAlexander von Humboldt and his correspondents liked to enrich or embellish their letters with quotations from classic works of ancient literature as well as from recent poems, plays, or novels. This paper tries to show that references to literature were very often used in order to express thoughts and feelings more clearly not so much for impressing the recipients of letters with high education. In educated circles a good knowledge of ancient and modern works of literature was a standard requirement, which often allowed the letter writers to use quotations in a playful manner.

  3. SQUID readout multiplexers for transition-edge sensor arrays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Adrian T. [Physics Department, University of California, Berkeley, CA 94720 (United States) and Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)]. E-mail: atl@physics.berkeley.edu

    2006-04-15

    Two classes of SQUID multiplexer are being developed for large arrays of cryogenic sensors, distinguished by their operation in either the time domain or frequency domain. Several systems optimized for use with Transition-Edge Sensors (TES) are reaching a high level of maturity, and will be deployed on funded astrophysics experiments in the next several years. A useful technical figure of merit is the product of the number of detectors multplexed multipled by the bandwidth of the detectors, which can be termed the 'total signal bandwidth' of a multiplexer system. This figure of merit is comparable within a factor of two for the mature systems. Several new concepts for increasing the total bandwidth are being developed in the broad class of frequency domain multiplexers. Another notable area of progress is in the level of integration of muliplexer and detector array. The time domain system for SCUBA-II is a sophisticated bump-bonded sandwich structure, and the Jena/MPI group is integrating detectors and a time domain multiplexer on one substrate. Finally, the Kinetic Inductance Detectors (KID)/HEMT (non-SQUID) detector/multiplexer system, will be discussed briefly.

  4. Antibacterial Activity of Melanin from Cuttlefish and Squid Ink

    Directory of Open Access Journals (Sweden)

    Yuspihana Fitrial

    2017-08-01

    Full Text Available Marine environment comprises of many organism which are known to posses bioactive compound as a common means of self-defense or for the protection of eggs and embryos. Class Cephalopods (such as squidand cuttlefish are notable for their defences, such as jetting escape movements, changes in colouration, toxic venom and inking.This study aims to compare the antibacterial activity of melanin from cuttlefish ink (Sepia sp. with squid ink (Loligo sp. against E. coli. Extraction and purification studies were carried out on Sepia and Loligo melanin using a hydrochloric acid 0,5M treatment under mechanical.The melanins were obtained and further evaluated their activity by direct contact methods between melanin and E. coli in nutrient broth.Total microbes was counted by total plate count.Both inks also was tested their activity against E. coli. The results showed that melanin from cuttlefish and squid inks had inhibitory activity at concentrations of 10 mg / ml and 20 mg / mL, respectively reaching 99.99% against E. coli.The inks of both Cephalopods at the same concentration as melanin, did not show any inhibitory activity against E. coli.  The melanin of Sepia sp. have a higher antibacterial activity than the melanin of Loligo sp.

  5. Reduction of environmental MHz noise for SQUID application

    Energy Technology Data Exchange (ETDEWEB)

    Araya, T. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)]. E-mail: araya@sup.ee.es.osaka-u.ac.jp; Kitamura, Y. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Kamishiro, M. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Sakuta, K. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Itozaki, H. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)]. E-mail: itozaki@ee.es.osaka-u.ac.jp

    2006-10-01

    It is important to remove large environmental noise in measurement using SQUIDs without magnetic shielding. Active noise control (ANC) is an effective method to remove the environmental noise. The environmental noise has been reduced by the ANC system in the radio frequency region around MHz. The anti-phase waves of the environmental noise should be generated by this system. The ANC system including the phase and amplitude control circuit was developed to make the anti-phase waves in the MHz region. In this paper, sinusoidal waves with a MHz frequency were used as the environmental noise. When a coil antenna was used for a receiver antenna, this ANC system suppressed these sinusoidal waves to the white noise level about 40 dB. When we used a SQUID as a receiver antenna, we also cancelled sinusoidal waves to the white noise level by this system. This shows that the ANC system is useful to reduce an environmental noise when this ANC system is developed to cancel multi-frequency noise.

  6. Reduction of environmental MHz noise for SQUID application

    International Nuclear Information System (INIS)

    Araya, T.; Kitamura, Y.; Kamishiro, M.; Sakuta, K.; Itozaki, H.

    2006-01-01

    It is important to remove large environmental noise in measurement using SQUIDs without magnetic shielding. Active noise control (ANC) is an effective method to remove the environmental noise. The environmental noise has been reduced by the ANC system in the radio frequency region around MHz. The anti-phase waves of the environmental noise should be generated by this system. The ANC system including the phase and amplitude control circuit was developed to make the anti-phase waves in the MHz region. In this paper, sinusoidal waves with a MHz frequency were used as the environmental noise. When a coil antenna was used for a receiver antenna, this ANC system suppressed these sinusoidal waves to the white noise level about 40 dB. When we used a SQUID as a receiver antenna, we also cancelled sinusoidal waves to the white noise level by this system. This shows that the ANC system is useful to reduce an environmental noise when this ANC system is developed to cancel multi-frequency noise

  7. Impact of SQUIDs on functional imaging in neuroscience

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. (paper)

  8. Humboldteanización del mundo occidental? La importancia del viaje de Humboldt para Europa y América Latina

    Directory of Open Access Journals (Sweden)

    Michael Zeuske

    2003-04-01

    Full Text Available Article in Spanish, Abstracts in English and German.The article “Humboldization of the Western world? The importance of the travel of Humboldt for Europa and for Latin America”, treats the empirical Prussian Scientist as a globalist (Universalgelehrten, in accordance to the conceptualization made by Ottmar Ette. Humboldt was one, if not the most important founder of Western moderne. As opposed to the well-known founders of the moderne (Descartes, Kant, Buffon, Schiller, Hegel, Marx ... etc., Alexander von Humboldt was an empirical and a global thinker. He did this in transcultural manners, sometimes already in intercultural manners. But most of times, his point of view is based in the European tradition of roman-classicist and aesthetic thinking. The article tries to demonstrate three types of knowledge in Humboldt and also, that the humboldtian universalism has important intercultural bases in the comunication with American scientists and in the American empiricism (“local knowledge”. One importance of such a conceptualization of Humboldt is shown – in negation – in the actual debates over diaspora and race in the Atlantic world (“Black Atlantic”. Humboldt knowledge of American slaveries and his absolute condemnation of slavery in his “Island of Cuba” is not present in these debates. In the second part the article demonstrates possibles manners of reading the diaries of Humboldt, by constructing “essais imaginaires” about colonialism, slavery, Peru, the Pacific ocean etc.

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

    Science.gov (United States)

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

    2017-05-01

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

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

    Science.gov (United States)

    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.

  11. Sensitive YBCO nanoSQUIDs for the investigation of small spin systems

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Benedikt; Schwarz, Tobias; Woelbing, Roman; Martinez-Perez, Maria Jose; Kleiner, Reinhold; Koelle, Dieter [Tuebingen Univ. (Germany). Physikalisches Inst. and Center for Collective Quantum Phenomena in LISA+; Reiche, Christopher F.; Muehl, Thomas; Buechner, Bernd [Leibniz Institute for Solid State and Materials Research IFW Dresden (Germany)

    2015-07-01

    We report on advances in the realization of dc YBCO nanoSQUIDs for continuous measurement of magnetic nanoparticle magnetization loops in strong magnetic fields up to the Tesla range, applied in the plane of the SQUID loop at temperatures of 4 K and below. Our grain boundary junction based YBCO SQUIDs are patterned by focused ion beam milling and feature a constriction next to the SQUID loop, allowing for on-chip SQUID modulation and bias reversal readout schemes. Using numerical simulations based on London theory, the spin sensitivity S{sub μ}{sup 1/2} = S{sub Φ}{sup 1/2} / φ{sub μ} was improved by optimizing both the flux noise S{sub Φ}{sup 1/2} and the coupling factor φ{sub μ} = Φ / μ (Φ is the magnetic flux coupled into the SQUID loop by a particle with magnetic moment μ). For optimized experimental devices, flux noise levels down to 50 nΦ{sub 0} / Hz{sup 1/2} in the white noise limit have been achieved, corresponding to a calculated spin sensitivity of only a few μ{sub B} / Hz{sup 1/2}. Further, the magnetization reversal of a Fe filled carbon nanotube attached to a YBCO nanoSQUID was traced out.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukade, Y., E-mail: hatukade@ens.tut.ac.jp [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Hayashi, K.; Shinyama, Y.; Kobayashi, Y. [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Adachi, S.; Tanabe, K. [International Superconductivity Technology Center/Superconductivity Research Laboratory, 10-13, Shinonome 1-chome, Koto-ku, Tokyo 135-0062 (Japan); Tanaka, S. [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)

    2011-11-15

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

  13. COLOMBIAN FROZEN BIODIVERSITY: 16 YEARS OF THE TISSUE COLLECTION OF THE HUMBOLDT INSTITUTE

    Directory of Open Access Journals (Sweden)

    Enrique Arbeláez-Cortés

    2015-05-01

    Full Text Available Collections of tissue samples stand as keystone sources of molecular information to construct biodiversity knowledge, and are particularly useful in megadiverse countries. In 1998 the Humboldt Institute (Instituto de Investigación de Recursos Biológicos Alexander von Humboldt began a tissue collection of Colombian biodiversity (IAvH-CT and the aim of this work is to present a diagnostic and an historical narrative for that collection, constructed by compiling information and experiences on its management as well as by organizing and curating the information of each catalogued sample. After 16 years the IAvH-CT harbors 16469 samples, which represent around 2530 species from 1289 genera, and 323 families of the Colombian biodiversity. Samples are biased toward plants and birds (84 %, but also include other animal taxa. Geographically, IAvH-CT includes samples from all Colombian departments, but there is a broad variation in their coverage. When compared with other international collections IAvH-CT fulfills several standards of sample storage and data management, but have a major weakness that is that several tissues seem to lack a vouchered specimen. Tissues housed at IAvH-CT have been included in at least 48 studies published in several scientific journals. IAvH-CT is implementing strategies to improve curatorial standards, fill-up taxonomic gaps, and to explore the potential of its samples to understand the outstanding Colombian biota in a cooperative research frame among institutions.

  14. Nachrichten aus Amerika oder wie man in Koblenz von Humboldts Reise nach Amerika erfuhr

    Directory of Open Access Journals (Sweden)

    Franz-J. Weihrauch

    2006-04-01

    Full Text Available Article in German, Abstracts in English and German.In the almost forgotten Jacobinic newspaper “Der Bewohner des West Rheins” (i.e. The Citizen of the Western Rhine, published in Koblenz/Rhine there appeared on Brumaire 29th of the year IX (i.e. November 20th 1800 a summary of a letter dated January 24th, 1800, sent by Alexander von Humboldt from Laguaira, Venezuela to his colleague Antoine François de Fourcroy (1755-1809 in Paris. It takes Humboldt’s letter six months to reach the French capital and further four months later it arrives in the (at that time French province of the departements on the left bank of the Rhine. This up to now unknown publication of a a letter by Humboldt in the newspaper “Der Bewohner des West Rheins”, a paper of only regional significance, vividly shows two parallel developments: on the one hand the spreading of knowledge from the centre to the perifery, from the capital to the province and on the other hand the spreading of knowledge from the already highly specialized scientific network to the general newspaper business that “generates” publicity and popularizes knowledge.

  15. Closing and opening fisheries following oil spills; a case study in Humboldt Bay, California

    International Nuclear Information System (INIS)

    Challenger, G.E.; Mauseth, G.S.

    1998-01-01

    The issue of fishery evaluation criteria following oil spills in lakes, rivers and seas was discussed. The case of the November 1997 incident in which 4,450 gallons of an intermediate fuel oil was released into Humboldt Bay, California was described. Humboldt Bay contains important shellfish mariculture operations that were subsequently closed by the California Dept. of Health Services (CDHS). The closure and reopening protocols for the fishery were summarized. Suggestions for technical input to resource management decisions were presented. During an initial meeting with regulatory agencies, four levels of criteria were established for rescinding the fishery closure. The fishery closure would be rescinded when: (1) there was a lack of visible oil sheen on the water throughout the commercial growing areas, (2) shellfish tissue samples met the risk-based criteria developed by CDHS, for all analytes of concern in the source oil, (3) all water samples met the risk-based criteria developed by CDHS for all analytes of concern in the source oil, and (4) tissue samples passed an independent sensory evaluation. However, no risk-based water quality criteria were developed and only items 1, 2, and 4 were included in the analysis. 15 refs., 3 tabs., 1 fig

  16. What Would Humboldt Say: A Case of General Bildung in Vocational Education?

    Directory of Open Access Journals (Sweden)

    Ruhi Tyson

    2016-12-01

    Full Text Available A classic philosopher in the Bildung tradition, Humboldt argued that general Bildung was the opposite of specialist training (vocational education. This has been a matter of contention and the aim here is to revisit the issue through an empirical case study. In the vocational education biography of craft master Wolfgang B. he speaks about aspects of his education that have much in common with Humboldt’s ideal of general Bildung but transposed into the context of vocational education and training (VET. The concept of vocationalism (Beruflichkeit provides context to the present argument which is that the contrast Humboldt made is relevant but not in the sense of there being two categories of education (general and vocational but rather two expressions of pedagogy: one expansive and one exclusive. Furthermore, there are two versions of general or expansive Bildung present in the case. The conclusions are that empirical studies of vocational Bildung expand on the concept of Bildung, increase our understanding of how VET contains affordances of Bildung and of the curriculum-patterns related to this.

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

    Science.gov (United States)

    Weinstock, H.

    1993-04-01

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

  18. Radio frequency interference noise reduction using a field programmable gate array for SQUID applications

    International Nuclear Information System (INIS)

    Sakuta, K; Narita, Y; Itozaki, H

    2007-01-01

    It is important to remove large environmental noise in superconducting quantum interference device (SQUID) measurement without magnetic shielding. Active noise control (ANC) is one of the effective methods to reduce environmental noise. Recently, SQUIDs have been used in various applications at high frequencies, such as nuclear quadrupole resonance (NQR). The NQR frequency from explosives is in the range 0.5-5 MHz. In this case, an NQR sensor is exposed to AM radio frequency interference (RFI). The feasibility of the ANC system for RFI that used digital signal processing was studied. Our investigation showed that this digital ANC system can be applied to SQUID measurements for RFI suppression

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

    Science.gov (United States)

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

    2017-07-01

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

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

    Science.gov (United States)

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

    2008-06-15

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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 8MHz with 1m wire length, which is enough for a TES to be operated with a bias current of 70μA, and a noise level of 30pA/Hz

  2. Step edge Josephson junctions and high temperature superconducting quantum interference device (SQUID) gradiometers

    International Nuclear Information System (INIS)

    Millar, Alasdair J.

    2002-01-01

    This thesis is concerned with the development of Superconducting Quantum Interference Device (SQUID) gradiometers based on the high temperature superconductor YBa 2 Cu 3 O 7-δ (YBCO). A step-edge Josephson junction fabrication process was developed to produce sufficiently steep (>60 deg) step-edges such that junctions exhibited RSJ-like current-voltage characteristics. The mean I C R N product of a sample of twenty step-edge junctions was 130μV. Step-edge dc SQUIDs with inductances between 67pH and 114pH were fabricated. Generally the SQUIDs had an intrinsic white flux noise in the 10-30μΦ 0 /√Hz range, with the best device, a 70pH SQUID, exhibiting a white flux noise of 5μΦ 0 /√Hz. Different first-order SQUID gradiometer designs were fabricated from single layers of YBCO. Two single-layer gradiometer (SLG) designs were fabricated on 10x10mm 2 substrates. The best balance and lowest gradient sensitivity measured for these devices were 1/300 and 308fT/cm√Hz (at 1 kHz) respectively. The larger baseline and larger flux capture area of the pick-up loops in a large area SLG design, fabricated on 30x10mm 2 substrates, resulted in significant improvements in the balance and gradient field sensitivity with 1/1000 and 50fT/cm√Hz (at 1kHz) measured respectively. To reduce the uniform field effective area of SLOs and therefore reduce the direct pick-up of environmental field noise when operated unshielded, a novel gradiometric SQUID (G-SQUID) device was developed. Fabricated from a single layer of YBCO, the G-SQUIDs with inductances of 67pH, had small uniform field effective areas of approximately 2μm 2 - more than two orders of magnitude smaller than the uniform field effective areas of conventional narrow linewidth SQUIDs of similar inductance. Two designs of G-SQUID were fabricated on 10x10mm 2 substrates. Due to their small effective areas, when cooled unshielded these devices showed no increase in their white flux noise. The best balance achieved for a G-SQUID

  3. „Vater einer großen Nachkommenschaft von Forschungsreisenden ...“ Ehrungen Alexander von Humboldts im Jahre 1869

    Directory of Open Access Journals (Sweden)

    Ilse Jahn

    2004-04-01

    Full Text Available Article in German, Abstracts in English and GermanIn 1869 the “Naturwissenschaftlicher Verein” was founded in Magdeburg (Saxony Anhalt. That was the time when the scientific world celebrated Alexander von Humboldt’s 100th birthday. In this context, Humboldt’s achievements were remembered during the founding ceremony of that society. The paper which was read in September 2003 on a meeting of this organisation, focuses on three famous naturalists who celebrated Humboldt because they owed him much help in their own professional careers. The botanist Matthias Jacob Schleiden gave a memorial speech in 1869 in Dresden. The physiologist and pioneer of electro-biology Emil du Bois-Reymond honoured his mentor A. v. Humboldt on the occasion of the dedication of the statues of Wilhelm and Alexander in 1883 in Berlin. Charles Darwin expressed his gratitude to Humboldt by sending him in 1839 the report of his travels and received an interesting reply. These three scholars represented a new epoch in the development of the natural sciences. The paper includes a recently re-discovered letter from Humboldt to Schleiden, dated April 13, 1842.

  4. Le temps du paysage. Alexandre de Humboldt et la géohistoire du sentiment de la nature

    OpenAIRE

    Briffaud , Serge

    2006-01-01

    L'article propose une analyse de la théorie de Humboldt, exposé notamment dans Cosmos, sur l'histoire du sentiment de la nature et les étapes de l'émergence d'une vision "paysagère" de la nature en Occident.

  5. Alexander von Humboldt und Carl Friedrich Gauß als Wegbereiter der neuen Disziplin Erdmagnetismus

    Directory of Open Access Journals (Sweden)

    Karin Reich

    2011-03-01

    Full Text Available AbstractThough Alexander von Humboldt was motivated for the first time to deal with earthmagnetism during his stay in Freiberg, it was in France that he really became a specialist in this respect. During most of his journeys he made earthmagnetic measurements. His collaboration with Arago was of great importance, it was in Paris that the first magnetic observatory was built. Humboldt rendered outstanding services to the investigation of earth magnetism by two major achievements: 1. He emphasized intensity measurements and 2. he put forward the law that the magnetic intensity is increasing from the magnetic equator toward the magnetic poles. At least since 1803 Carl Friedrich Gauss was interested in earthmagnetism and especially in Humboldt’s early published data. That Wilhelm Weber became professor of physics at the University of Göttingen in 1831 was a turning point for Gauss. In 1833 Göttingen was the centre of investigating earthmagnetism, a new era began which lasted only until 1843. Gauss’ main contributions were more or less theoretical, in 1832/3 he transformed Humboldt’s relative intensity measurements into absolute ones which were independent of the instrument’s needle. A new epoch began with Gauss’ publication „Allgemeine Theorie des Erdmagnetismus” (1839. The main point was the newly defined notion of „potential“. Gauss was the first to present the surface of the earth with equipotential lines. ZusammenfassungAlexander von Humboldt hatte sich bereits in Freiberg mit dem Erdmagnetismus beschäftigt; jedoch erst in Frankreich lernte er die entsprechenden Beobachtungsmethoden kennen. Auf allen seinen Reisen machte er erdmagnetische Messungen. Seine Zusammenarbeit mit Arago in Paris war besonders fruchtbar, hier wurde das erste magnetische Observatorium gebaut. Humboldt beschäftigte sich vor allem mit Intensitätsmessungen; sein wichtigster Beitrag war die Feststellung, dass die magnetische Intensität vom

  6. Magnetic imaging of unconventional superconductors by scanning SQUID microscopy

    International Nuclear Information System (INIS)

    Hykel, D.

    2011-01-01

    We present the development of a scanning SQUID/AFM microscope and measurements performed on different samples. The microscope can take topographic and magnetic images simultaneously. The magnetic resolution is of the order of 10 -4 Φ 0 √Hz and the spatial resolution of the SQUIDs used in this thesis goes up to 600 nm. The scanning range is 70 μm * 85 μm. The temperature range accessible is between 200 mK and 10 K at the time of writing. Measurements on a thin rhenium film (80 nm) give an estimate of the minimal pinning force of a vortex of about 3.9 * 10 -16 N. Furthermore, the penetration depth λ on this sample was determined as a function of temperature. For T → 0, λ →79 nm. We have for the first time shown local measurements of the domain structure of the superconducting ferromagnet UCoGe and determined the average domain size in the virgin state (10 μm). By magnetic imaging we were capable of determining the magnetic field difference above opposite domains along the c-axis to be 45 G and 16 G along the b-axis. Due to these magnetic field measurements we were able to give an upper limit for the domain wall width (∼ 1μm) and domain reconstruction depth (100 nm). This is supported by simple calculations leading to a domain wall width of several angstroms. Thus UCoGe can be considered an ideal Ising ferromagnet. Different possible domain structures for an Ising ferromagnet have been discussed. The complicated domain structure found in the zero field cooled virgin state corresponds to up domains embedded in larger down domains and vice versa. We have shown evidence for coexistence of superconductivity and ferromagnetism. The weak Meissner effect can be explained by a spontaneous vortex state, put forward by other groups. Numerical simulations suggest that the strong magnetic background signal and the limited spatial and magnetic resolution of the used SQUID made it difficult to resolve the expected spontaneous vortex state. The relaxation of the

  7. Multichannel DC SQUID sensor array for biomagnetic applications

    International Nuclear Information System (INIS)

    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.

    1991-01-01

    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 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)

  8. Detection of Rapid Atrial Arrhythmias in SQUID Magnetocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Woong; Kwon, Hyuk Chan; Kim, Ki Dam; Lee, Yong Ho; Kim, Jin Mok; Kim, In Seon; Lim, Hyun Kyoon; Park, Yong Ki [Biomagnetism Research, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kim, Doo Sang [Seoul Veterans Hospital, Seoul (Korea, Republic of); Lim, Seung Pyung [Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2005-10-15

    We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was 10 fT/Hz(a) 1 Hz and 5 fT/Hz(a) 100 Hz. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

  9. SQUID-detected magnetic resonance imaging in microtesla magnetic fields

    International Nuclear Information System (INIS)

    McDermott, Robert; Kelso, Nathan; Lee, SeungKyun; Moessle, Michael; Mueck, Michael; Myers, Whittier; Haken, Bernard ten; Seton, H.C.; Trabesinger, Andreas H.; Pines, Alex; Clarke, John

    2003-01-01

    We describe studies of nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) of liquid samples at room temperature in microtesla magnetic fields. The nuclear spins are prepolarized in a strong transient field. The magnetic signals generated by the precessing spins, which range in frequency from tens of Hz to several kHz, are detected by a low-transition temperature dc SQUID (Superconducting QUantum Interference Device) coupled to an untuned, superconducting flux transformer configured as an axial gradiometer. The combination of prepolarization and frequency-independent detector sensitivity results in a high signal-to-noise ratio and high spectral resolution (∼1 Hz) even in grossly inhomogeneous magnetic fields. In the NMR experiments, the high spectral resolution enables us to detect the 10-Hz splitting of the spectrum of protons due to their scalar coupling to a 31P nucleus. Furthermore, the broadband detection scheme combined with a non-resonant field-reversal spin echo allows the simultaneous observation of signals from protons and 31P nuclei, even though their NMR resonance frequencies differ by a factor of 2.5. We extend our methodology to MRI in microtesla fields, where the high spectral resolution translates into high spatial resolution. We demonstrate two-dimensional images of a mineral oil phantom and slices of peppers, with a spatial resolution of about 1 mm. We also image an intact pepper using slice selection, again with 1-mm resolution. In further experiments we demonstrate T1-contrast imaging of a water phantom, some parts of which were doped with a paramagnetic salt to reduce the longitudinal relaxation time T1. Possible applications of this MRI technique include screening for tumors and integration with existing multichannel SQUID systems for brain imaging

  10. SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

    Energy Technology Data Exchange (ETDEWEB)

    Moessle, Michael; Hatridge, Michael; Clarke, John

    2006-08-14

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

    Science.gov (United States)

    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.

  12. Technology for SQUID systems for the application in magnetically disturbed environment. Final report

    International Nuclear Information System (INIS)

    Schultze, V.; Fritzsch, L.; Thrum, F.; Stolz, R.; Chwala, A.

    1996-06-01

    International available SQUID systems, as used for example in biomagnetic research, obtain high sensitivities for magnetic fields or magnetic fieldgradients. However, these systems were optimised for operation in magnetically shielded rooms. Goal of this project was to develop SQUIDs suppressing the external noise and therefore are able to operate without external shielding in normal environments. As a consequence, the required Nb/AlO x /Nb technology has also been developed. The resulting planar SQUID gradiometers as produced at the IPHT, reached a suppression of homogeneous fields up to 5 x 10 4 for a magnetic field sensitivity c , project. SQUID gradiometers, produced using YBCO technology, were successfully operated in non shielded eddy current NDE measurements in the lab. (orig.) [de

  13. Growth of juvenile shrimp Metapenaeus monoceros fed with squid and mussel

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Nair, S.R.S.; Krishnakumari, L.

    Small juveniles of both sexes and females of large juveniles of Metapenaeus monoceros attained faster growth with squid diet. Males of large juveniles registered better growth with mussel diet. No significant difference was observed in moult weights...

  14. High-T /SUB c/ Superconducting integrated circuit: a dc SQUID with input coil

    International Nuclear Information System (INIS)

    Di Iorio, M.S.; Beasley, M.R.

    1985-01-01

    We have fabricated a high transition temperature superconducting integrated circuit consisting of a dc SQUID and an input coupling coil. The purpose is to ascertain the generic problems associated with constructing a high-T /SUB c/ circuit as well as to fabricate a high performance dc SQUID. The superconductor used for both the SQUID and the input coil is Nb 3 Sn which must be deposited at 800 0 C. Importantly, the insulator separating SQUID and input coil maintains its integrity at this elevated temperature. A hole in the insulator permits contact to the innermost winding of the coil. This contact has been achieved without significant degradation of the superconductivity. Consequently, the device operates over a wide temperature range, from below 4.2 K to near T /SUB c/

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

    Science.gov (United States)

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

    2002-03-01

    Performance for a recently completed whole-head magnetoencephalography system using a superconducting imaging surface (SIS) surrounding an array of 150 SQUID magnetometers is reported. The helmet-like SIS is hemispherical in shape with a brim. Conceptually, the SIS images nearby sources onto the SQUIDs while shielding sensors from distant “noise” sources. A finite element method (FEM) description using the as-built geometry was developed to describe the SIS effect on source fields by imposing B⊥( surface)=0 . Sensors consist of 8×8 mm 2 SQUID magnetometers with 0.84 nT/ Φ0 sensitivity and positions and orientations was found. Good agreement was found between modeled and measured shielding of the SQUIDs from sources external to the array showing significant frequency-independent shielding. Phantom localization precision was better than 0.5 mm at all locations with a mean of better than 0.3 mm.

  16. Development of a Flow-Through SQUID System for Non-Destructive Evaluation of MRI Wire

    National Research Council Canada - National Science Library

    Wellstood, Frederick C

    2007-01-01

    ...) superconducting quantum interference device (SQUID) system. The ability to detect small defects in km-long sections of NbTi magnet wire could improve the production yield of high-field magnets for power and medical applications...

  17. Analysis of the ac SQUID with low inductance and low critical current

    DEFF Research Database (Denmark)

    Sørensen, O. H.

    1976-01-01

    The properties of the ac SQUID magnetometer has been analyzed. The results are valid in the low-inductance low-critical-current regime, where the Lri0 producted is belowthe value at which the relation between the enclosed and externally applied magnetic dc flux becomes reentrant. The effects...... of the screening current circulating in the SQUID ring as well as of the SQUID-ring time constant, tau-Lr/R9 are taken into account. Here LR IS THE SQUID-ring inductance, and R is the shunt resistance in the shunted junction model assumed to describe the weak link. It is shown that for finite values of omegatau...... constriuctively with the result that the optimal response occurs at a definite and finite value of omegatau. If omegatau is increased beyond this optimal value the weak link behavior is dominated by the Ohmic current channel implying that only if the shunt conductance contains a term depending...

  18. 76 FR 66260 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Science.gov (United States)

    2011-10-26

    ...) of scup, 184,280 lb (83,588 kg) of black sea bass, and 200,000 lb (90,718 kg) of bluefish. Project... summer flounder, scup, black sea bass, longfin squid, butterfish, and Atlantic bluefish, and assessment...

  19. The bases for the development of high-temperature integrated SQUID-systems

    International Nuclear Information System (INIS)

    Polushkin, V.N.

    1992-01-01

    The current state of high-T c superconducting thin-film Josephson junctions and SQUIDs developing is reviewed. The prospects of application of new devices in supersensitive measurement apparatus are analyzed. It is shown that high T c SQUIDs are able seriously to influence further development of information and measurement engineering as on their base the series of microelectronic elements and devices of new generation can be built. 55 refs.; 7 figs.; 2 tabs

  20. The bases for the development of high-temperature integrated squid-systems

    International Nuclear Information System (INIS)

    Polushkin, V.N.

    1992-01-01

    The current state of high-Tc superconducting thinfilm Josepson junctions and SQUIDs developing is reviewed. The prospects of application of new devices in supersensitive measurement apparatus are analyzed. It is shown that high T c SQUIDs are able seriously to influence further development of information and measurement engineering as on their base the series of microelectronic elements and devices of new generation can be built. 84 refs.; 16 figs.; 3 tabs

  1. Temperature profile data collected from the ALE ANDRO DE HUMBOLDT from 19 September 1971 to 26 September 1971 (NODC Accession 7500942)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bottle casts from the ALE ANDRO DE HUMBOLDT in the coastal waters of California from 19 September 1971 to 26 September...

  2. PHYTOPLANKTON - WET WEIGHT and Other Data from ALE ANDRO DE HUMBOLDT From North Pacific Ocean from 19780108 to 19780407 (NODC Accession 9700071)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Phytoplankton data were collected from net tows from the Ale Andro De Humboldt in the North Pacific Ocean from 08 January 1978 to 07 April 1978. Chlorophyll A and...

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

    Science.gov (United States)

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

    2012-07-01

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

  4. A Alexander von Humboldt, el Ciudadano Universal, en su natalicio 245

    Directory of Open Access Journals (Sweden)

    José Leonardo De Sousa

    2018-04-01

    Full Text Available Hace 245 años, en la escala del tiempo del planeta, Alexander von Humboldt vislumbró la luz de la vida el día 14 de septiembre de 1769. A nuestro entender fue el máximo y, quizás, uno de los últimos exponentes de ese movimiento del Enciclopedismo Europeo conocido como la Ilustración . Tal fue su contribución al conocimiento integral del territorio americano que fue calificado por el Libertador Simón Bolívar como el “ descubridor científico del Nuevo Mundo ” y declarado como Ciudadano Mexicano, en 1827, por Guadalupe Victoria (primer presidente de México y luego, como Benemérito de la Patria por el presidente mexicano Benito Juárez.

  5. Influence of inductance induced noise in an YBa2Cu3O7 dc-SQUID at high operation temperatures

    DEFF Research Database (Denmark)

    Nilsson, P. Å.; Claeson, T.; Hansen, J. B.

    1994-01-01

    The voltage modulation depth of a high T(c) dc-SQUID was measured at temperatures close to T(c) and compared to a model by Enpuku et al. where the flux noise from the SQUID inductance is taken into account. The device was an YBa2Cu3O7 dc-SQUID made on a bicrystal substrate of SrTiO3. The design w...

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

    Science.gov (United States)

    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.

  7. Optical parameters of the tunable Bragg reflectors in squid.

    Science.gov (United States)

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

    2013-08-06

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

  8. Percepción, descripción y explicación en la obra de Alexander Von Humboldt

    Directory of Open Access Journals (Sweden)

    Bárbara Jiménez Pazos

    2017-01-01

    Full Text Available Es recurrente la tendencia a considerar a Alexander von Humboldt como autor romántico-naturalista, dada la combinación del método científico de análisis empírico de la naturaleza con su visión estético-subjetiva que posee ciertos rasgos "románticos". Un estudio del léxico empleado por Humboldt en las descripciones de la naturaleza revela, sin embargo, el predominio del lenguaje estrictamente científico e intersubjetivo sobre el subjetivo. La presencia de rasgos semánticos "románticos" no es, empero, meramente ornamental, sino que cumple una función estética que, en la percepción humboldtiana de la naturaleza, es un complemento subjetivo indispensable dentro de su imagen holística del mundo.

  9. Figures et Unité de l’idée de montagne chez Alexandre von Humboldt

    OpenAIRE

    Debarbieux, Bernard

    2012-01-01

    Bien que la montagne soit omniprésente dans ses écrits, Alexandre von Humboldt n’a consacré aucun de ses ouvrages en particulier à ce type de région ou de milieu. Cet essai propose d’expliciter le statut de la montagne en tant que catégorie de la connaissance dans la vision du monde qu’Humboldt a élaborée. Plus précisément, cet essai montre que derrière la diversité apparente des façons qu’il a de mobiliser la notion, il existe une cohérence d’ensemble dont il n’a jamais véritablement rendu c...

  10. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

  11. Microwave SQUID multiplexer demonstration for cosmic microwave background imagers

    Science.gov (United States)

    Dober, B.; Becker, D. T.; Bennett, D. A.; Bryan, S. A.; Duff, S. M.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Hubmayr, J.; Mates, J. A. B.; Reintsema, C. D.; Vale, L. R.; Ullom, J. N.

    2017-12-01

    Key performance characteristics are demonstrated for the microwave superconducting quantum interference device (SQUID) multiplexer (μmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the μmux produces a white, input referred current noise level of 29 pA/ √{H z } at a microwave probe tone power of -77 dB, which is well below the expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98 pA/ √{H z } in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to ˜100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the μmux as a viable readout technique for future CMB imaging instruments.

  12. Development of improved superconductive axial gradiometers for biomagnetic SQUID applications

    Science.gov (United States)

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

    2018-03-01

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

  13. An interchangeable scanning Hall probe/scanning SQUID microscope

    International Nuclear Information System (INIS)

    Tang, Chiu-Chun; Lin, Hui-Ting; Wu, Sing-Lin; Chen, Tse-Jun; Wang, M. J.; Ling, D. C.; Chi, C. C.; Chen, Jeng-Chung

    2014-01-01

    We have constructed a scanning probe microscope for magnetic imaging, which can function as a scanning Hall probe microscope (SHPM) and as a scanning SQUID microscope (SSM). The scanning scheme, applicable to SHPM and SSM, consists of a mechanical positioning (sub) micron-XY stage and a flexible direct contact to the sample without a feedback control system for the Z-axis. With the interchangeable capability of operating two distinct scanning modes, our microscope can incorporate the advantageous functionalities of the SHPM and SSM with large scan range up to millimeter, high spatial resolution (⩽4 μm), and high field sensitivity in a wide range of temperature (4.2 K-300 K) and magnetic field (10 −7 T-1 T). To demonstrate the capabilities of the system, we present magnetic images scanned with SHPM and SSM, including a RbFeB magnet and a nickel grid pattern at room temperature, surface magnetic domain structures of a La 2/3 Ca 1/3 MnO 3 thin film at 77 K, and superconducting vortices in a striped niobium film at 4.2 K

  14. Development of Contaminant Detection System using HTS SQUIDs

    International Nuclear Information System (INIS)

    Ohtani, T.; Tanaka, S.; Narita, Y.; Ariyoshi, S.; Suzuki, S.

    2015-01-01

    In terms of food safety, mixture of contaminants in food is a serious problem for not only consumers but also manufacturers. In general, the target size of the metallic contaminant to be removed is 0.5 mm. However, it is a difficult task for manufacturers to achieve this target, because of lower system sensitivity. Therefore, we developed a food contaminant detection system based on high-Tc RF superconducting quantum interference devices (SQUIDs), which are highly sensitive magnetic sensors. This study aims to improve the signal to noise ratio (SNR) of the system and detect a 0.5 mm diameter steel ball. Using a real time digital signal processing technique along with analog band-pass filters, we improved the SNR of the system. Owing to the improved SNR, a steel ball with a diameter as small as 0.3 mm, with stand-off distance of 117 mm was successfully detected. These results suggest that the proposed system is a promising candidate for the detection of metallic contaminants in food products

  15. An interchangeable scanning Hall probe/scanning SQUID microscope

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chiu-Chun; Lin, Hui-Ting; Wu, Sing-Lin [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Chen, Tse-Jun; Wang, M. J. [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Ling, D. C. [Department of Physics, Tamkang University, Tamsui Dist., New Taipei City 25137, Taiwan (China); Chi, C. C.; Chen, Jeng-Chung [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2014-08-15

    We have constructed a scanning probe microscope for magnetic imaging, which can function as a scanning Hall probe microscope (SHPM) and as a scanning SQUID microscope (SSM). The scanning scheme, applicable to SHPM and SSM, consists of a mechanical positioning (sub) micron-XY stage and a flexible direct contact to the sample without a feedback control system for the Z-axis. With the interchangeable capability of operating two distinct scanning modes, our microscope can incorporate the advantageous functionalities of the SHPM and SSM with large scan range up to millimeter, high spatial resolution (⩽4 μm), and high field sensitivity in a wide range of temperature (4.2 K-300 K) and magnetic field (10{sup −7} T-1 T). To demonstrate the capabilities of the system, we present magnetic images scanned with SHPM and SSM, including a RbFeB magnet and a nickel grid pattern at room temperature, surface magnetic domain structures of a La{sub 2/3}Ca{sub 1/3}MnO{sub 3} thin film at 77 K, and superconducting vortices in a striped niobium film at 4.2 K.

  16. Dynamic Characteristics of S-band DC SQUID Amplifier

    DEFF Research Database (Denmark)

    Prokopenko, G. V.; Shitov, S. V.; Koshelets, I. L. L. V. P.

    2003-01-01

    A low-noise rf amplifier based on a de SQUID (SQA) has been tested in the frequency range 3.0-4.6 GHz in the open-loop configuration. The following parameters have been measured for the single-stage balanced type SQA at 4.0 GHz: gain (12 +/- 1) dB, 3 dB bandwidth of 500 MHz and noise temperature (1.......0 +/- 0.25) K. For the nonbalanced type SQA at 4.0 GHz gain was (15 +/-1) dB, 3 dB bandwidth 200 MHz and noise temperature (0.5 +/- 0.25) K. The improved performance is obtained due to the increased characteristic voltage (approximate to 420 muV) of the small-area (down to 0.7-0.9 mum(2)) high-quality Nb......-AlOx-Nb SIS junctions. The saturation power (normalized to 1 GHz) referred to the input at 1 dB gain compression is estimated as approximate to55 K*GHz at a bias voltage of 60 muV. The reasons for saturation of the SQA are discussed....

  17. Sperm from sneaker male squids exhibit chemotactic swarming to CO₂.

    Science.gov (United States)

    Hirohashi, Noritaka; Alvarez, Luis; Shiba, Kogiku; Fujiwara, Eiji; Iwata, Yoko; Mohri, Tatsuma; Inaba, Kazuo; Chiba, Kazuyoshi; Ochi, Hiroe; Supuran, Claudiu T; Kotzur, Nico; Kakiuchi, Yasutaka; Kaupp, U Benjamin; Baba, Shoji A

    2013-05-06

    Behavioral traits of sperm are adapted to the reproductive strategy that each species employs. In polyandrous species, spermatozoa often form motile clusters, which might be advantageous for competing with sperm from other males. Despite this presumed advantage for reproductive success, little is known about how sperm form such functional assemblies. Previously, we reported that males of the coastal squid Loligo bleekeri produce two morphologically different euspermatozoa that are linked to distinctly different mating behaviors. Consort and sneaker males use two distinct insemination sites, one inside and one outside the female's body, respectively. Here, we show that sperm release a self-attracting molecule that causes only sneaker sperm to swarm. We identified CO2 as the sperm chemoattractant and membrane-bound flagellar carbonic anhydrase as its sensor. Downstream signaling results from the generation of extracellular H(+), intracellular acidosis, and recovery from acidosis. These signaling events elicit Ca(2+)-dependent turning behavior, resulting in chemotactic swarming. These results illuminate the bifurcating evolution of sperm underlying the distinct fertilization strategies of this species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. EFFECT OF DETERGENT ON ELECTRICAL PROPERTIES OF SQUID AXON MEMBRANE.

    Science.gov (United States)

    KISHIMOTO, U; ADELMAN, W J

    1964-05-01

    The effects of detergents on squid giant axon action and resting potentials as well as membrane conductances in the voltage clamp have been studied. Anionic detergents (sodium lauryl sulfate, 0.1 to 1.0 mM; dimethyl benzene sulfonate, 1 to 20 mM, pH 7.6) cause a temporary increase and a later decrease of action potential height and the value of the resting potential. Cationic detergent (cetyl trimethyl ammonium chloride, 6 x 10(-5)M or more, pH 7.6) generally brings about immediate and irreversible decreases in the action and resting potentials. Non-ionic detergent (tween 80, 0.1 M, pH 7.6) causes a slight reversible reduction of action potential height without affecting the value of the resting potential. Both anionic and cationic detergents generally decrease the sodium and potassium conductances irreversibly. The effect of non-ionic detergent is to decrease the sodium conductance reversibly, leaving the potassium conductance almost unchanged.

  19. Microwave SQUID Multiplexer Demonstration for Cosmic Microwave Background Imagers.

    Science.gov (United States)

    Dober, B; Becker, D T; Bennett, D A; Bryan, S A; Duff, S M; Gard, J D; Hays-Wehle, J P; Hilton, G C; Hubmayr, J; Mates, J A B; Reintsema, C D; Vale, L R; Ullom, J N

    2017-12-01

    Key performance characteristics are demonstrated for the microwave SQUID multiplexer (µmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the µmux produces a white, input referred current noise level of [Formula: see text] at -77 dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure [Formula: see text] in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e. phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to ~ 100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the µmux as a viable readout technique for future CMB imaging instruments.

  20. SQUID biosusceptometry in the measurement of hepatic iron

    International Nuclear Information System (INIS)

    Sheth, Sujit

    2003-01-01

    Individuals with primary or secondary abnormalities of iron metabolism, such as hereditary hemochromatosis and transfusional iron loading, may develop potentially lethal systemic iron overload. Over time, this excess iron is progressively deposited in the liver, heart, pancreas, and other organs, resulting in cirrhosis, heart disease, diabetes and other disorders. Unless treated, death usually results from cardiac failure. The amount of iron in the liver is the best indicator of the amount of iron in the whole body. At present, the only sure way to measure the amount of iron in the liver is to remove a sample of the liver by biopsy. Iron stored in the liver can be magnetized to a small degree when placed in a magnetic field. The amount of magnetization is measured by our instrument, called a superconducting quantum interference device (SQUID) susceptometer. In patients with iron overload, our previous studies have shown that magnetic measurements of liver iron in patients with iron overload are quantitatively equivalent to biochemical determinations on tissue obtained by biopsy. The safety, ease, rapidity, and comfort of magnetic measurements make frequent, serial studies technically feasible and practically acceptable to patients. (orig.)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2018-03-01

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

  3. Mobile HTS-SQUID NDE system with robot arm and active shielding using fluxgate

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukade, Y. [Department of Ecological Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)], E-mail: hatukade@eco.tut.ac.jp; Yotsugi, K.; Tanaka, S. [Department of Ecological Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)

    2008-09-15

    A robot-arm-based mobile HTS-SQUID NDE system was developed for inspection of advanced structures such as hydrogen fuel cell tanks. In order to realize stable operation of HTS-SQUID exposed in Earth's field and robot arm's noise without flux trapping, flux jumping and unlocking during motion, a new active magnetic shielding (AMS) technique using fluxgate was introduced. The high sensitive fluxgate, which could measure magnetic field of up to several 10 {mu}T, was mounted near an HTS-SQUID gradiometer on the robot arm to measure the ambient noise and feed back its output to a compensation coil, which surrounded both SQUID and fluxgate to cancel the ambient noise around them. The AMS technique successfully enabled the HTS-SQUID gradiometer to be moved at 10 mm/s by the robot arm in unshielded environment without flux trapping, jumping and unlocking. Detection of hidden slots in multi-layer composite-metal structures imitating the fuel cell tank was demonstrated.

  4. Development of Nb nanoSQUIDs based on SNS junctions for operation in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Morosh, Viacheslav; Kieler, Oliver; Weimann, Thomas; Zorin, Alexander [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Mueller, Benedikt; Martinez-Perez, Maria Jose; Kleiner, Reinhold; Koelle, Dieter [Physikalisches Institut and Center for Quantum Science in LISA+, Universitaet Tuebingen (Germany)

    2016-07-01

    Investigation of the magnetization reversal of single magnetic nanoparticles requires SQUIDs with high spatial resolution, high spin sensitivity (a few Bohr magneton μ{sub B}) and at the same time sufficient stability in high magnetic fields. We fabricated dc nanoSQUIDs comprising overdamped SNS sandwich-type (Nb/HfTi/Nb) Josephson junctions using optimized technology based on combination of electron beam lithography and chemical-mechanical polishing. Our nanoSQUIDs have Josephson junctions with lateral dimensions ≤ 150 nm x 150 nm, effective loop areas < 0.05 μm{sup 2} and the distance between the Josephson junctions ≤ 100 nm. The feeding strip lines of the width ≤ 200 nm have been realized. The nanoSQUIDs have shown stable operation in external magnetic fields at least up to 250 mT. Sufficiently low level of flux noise resulting in spin sensitivity of few tens μ{sub B}/Hz{sup 1/2} has been demonstrated. A further reduction of the nanoSQUID size using our technology is possible.

  5. SQUID magnetometer using sensitivity correction signal for non-magnetic metal contaminants detection

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Toshifumi, E-mail: sakuta.k@usp.ac.jp; Ohashi, Masaharu; Sakuta, Ken

    2016-11-15

    Highlights: • A high-frequency excitation is necessary to detect nonmagnetic metals using SQUID. • It is possible to detect a high-frequency magnetic field using the open loop technique. • Open loop operation leads to a change in the conversion factor. • Conversion between voltage and magnetic field for open loop operation are examined. - Abstract: Measurement methods with SQUID can accurately detect small magnetic metal contaminants based on their magnetic remanence. But, a high-frequency excitation is necessary to detect nonmagnetic metals, on the base of contrasts in electric conductivity. In this work, an open loop technique is introduced to facilitate this. The SQUID is negative feedback controlled (flux locked loop (FLL) operation) for the low frequency range, which includes significant noise due to the movement of the magnetic body or the change of the ambient magnetic field composed of the geomagnetic field and technical signals, and it operates in an open loop configuration for the high frequency range. When using the open loop technique, negative feedback is not applied to the high frequency range. Consequently, the V–Φ characteristic changes due to various causes, which leads to variations in the conversion factor between the SQUID output voltage and the magnetic field. In this study, conversion techniques for the magnetic field for open loop operation of SQUID in the high frequency range are examined.

  6. NANO-SQUIDs based on niobium Dayem bridges for nanoscale applications

    Energy Technology Data Exchange (ETDEWEB)

    Granata, C; Esposito, E; Nappi, C; Ruggiero, B; Russo, M [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, 80078 Pozzuoli (Napoli) (Italy); Vettoliere, A; Walke, P [Also Universita degli Studi di Napoli ' Federico II' , Napoli (Italy); Silvestrini, P, E-mail: c.granata@cib.na.cnr.i [Dipartimento di Ingegneria dell' Informazione, Seconda Universita degli Studi di Napoli, Aversa(Caserta) (Italy)

    2010-06-01

    We report on the design, the fabrication and the performance of an integrated magnetic nano-sensor based on niobium dc-SQUID (Superconducting QUantum Interference Device) for nanoscale applications is presented. The nano-sensors are based on nanometric niobium constrictions (Dayem bridges) inserted in a square loop having a side length of 200 nm. Measurements of voltage-flux characteristic, flux to voltage transfer factor and noise performances are reported. In small signal mode, the sensors have shown a magnetic flux noise spectral density of 1.5 {mu}{Phi}{sub 0}/Hz{sup 1/2} corresponding to a spin sensitivity in unit of Bohr magneton of 60 spin/Hz{sup 1/2}. Supercurrent decay measurements of these devices are also reported. Such measurements provide useful information for applications which employ the SQUID as a trigger where the sensor works on the zero voltage state. The experimental data, have shown an intrinsic current fluctuation less than 0.2% of the critical current at liquid helium temperature, corresponding to an intrinsic sensor magnetic flux resolution of a few m{Phi}{sub 0}. In view of the nano-SQUID employments in the detection of small spin populations, the authors calculated the spin sensitivity and the magnetic response relative to the single spin, as a function of its position within the SQUID hole. The results show that the SQUID response depends strongly on the spin position.

  7. RF SQUID in the nonhysteretic regime with k2Ql>1

    International Nuclear Information System (INIS)

    Dmitrenko, I.M.; Tsoi, G.M.; Shnyrkov, V.I.; Kartsovnik, V.V.

    1982-01-01

    Experimental measurements of current-voltage, current-phase, amplitude-frequency, phase-frequency, and signal characteristics of an rf SQUID operating at a frequency of 30 MHz in the nonhysteretic regime (1 = 2πL 0 I 0 /phi/sub o/ 2 Ql>1. Here I 0 is the critical current of the weak link, L 0 is the SQUID ring inductance, k is the coefficient of coupling of the SQUID ring to a resonant tank circuit of quality Q, and phi 0 is the magnetic flux quantum. A numerical analysis of the above characteristics for all relevant parameter values close to those occurring under experimental conditions was performed for qualitative comparison with theory. The main difference from the traditional nonhysteretic regime of SQUID operation (k 2 Q1 12 V/Wb for the single-valued region of the signal characteristics. The results suggest that considerable improvement of rf SQUID resolution is possible in the regime k 2 Ql>1

  8. SQUID magnetometer using sensitivity correction signal for non-magnetic metal contaminants detection

    International Nuclear Information System (INIS)

    Yagi, Toshifumi; Ohashi, Masaharu; Sakuta, Ken

    2016-01-01

    Highlights: • A high-frequency excitation is necessary to detect nonmagnetic metals using SQUID. • It is possible to detect a high-frequency magnetic field using the open loop technique. • Open loop operation leads to a change in the conversion factor. • Conversion between voltage and magnetic field for open loop operation are examined. - Abstract: Measurement methods with SQUID can accurately detect small magnetic metal contaminants based on their magnetic remanence. But, a high-frequency excitation is necessary to detect nonmagnetic metals, on the base of contrasts in electric conductivity. In this work, an open loop technique is introduced to facilitate this. The SQUID is negative feedback controlled (flux locked loop (FLL) operation) for the low frequency range, which includes significant noise due to the movement of the magnetic body or the change of the ambient magnetic field composed of the geomagnetic field and technical signals, and it operates in an open loop configuration for the high frequency range. When using the open loop technique, negative feedback is not applied to the high frequency range. Consequently, the V–Φ characteristic changes due to various causes, which leads to variations in the conversion factor between the SQUID output voltage and the magnetic field. In this study, conversion techniques for the magnetic field for open loop operation of SQUID in the high frequency range are examined.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukade, Y. [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)], E-mail: hatukade@eco.tut.ac.jp; Yotsugi, K. [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Sakaguchi, Y. [SAMTECH Corporation, 1000-18 Enmyo-cho, Kashiwara City, Osaka 582-0027 (Japan); Tanaka, S. [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)

    2007-10-01

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

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

    NARCIS (Netherlands)

    van den Bosch, P.J.; van den Bosch, P.J.; ter Brake, Hermanus J.M.; van den Eijkel, G.C.; Boelens, J.P.; Holland, Herman J.; Verberne, J.F.C.; Rogalla, Horst

    1994-01-01

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

  12. 76 FR 3044 - Fisheries of the Exclusive Economic Zone Off Alaska; Sculpins, Sharks, Squid, and Octopus in the...

    Science.gov (United States)

    2011-01-19

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

  13. The male reproductive strategy of a deep-sea squid : sperm allocation, continuous production, and long-term storage of spermatophores in Histioteuthis miranda

    NARCIS (Netherlands)

    Hoving, Hendrik Jan T.; Lipinski, Marek R.; Dam, Lammertjan

    2010-01-01

    Squid are semelparous organisms. Much of what we know about squid reproduction relates to females, because few studies have addressed males and, although males are similarly challenged by semelparity, it remains virtually unknown what tactics squid have evolved to allocate sperm to spermatophores.

  14. La influencia de Alejandro de Humboldt en dos artistas venezolanos del siglo XIX

    Directory of Open Access Journals (Sweden)

    Esteva-Grillet, Roldán

    2009-12-01

    Full Text Available Throughout century XIX in the Latin American painting several new subjects are introduced, among them the landscape, no longer more like scene of patriotic, religious or costumbristas scenes. The model propose by Alexander de Humboldt in its book Vue de cordillères et monuments des peuples indigènes de l’Amérique, of 1810, for the scientific study of the landscape, is going to be followed not only by artists German, but by nationals like Car it to me the Fernandez Páez and Ramon Bolet Peraza who will approach modestly in their work to the watercolor and the weather. First in its character of illustrator of the geographic work of Agustín Codazzi, as much in Venezuela as in Colombia, the second when taking care of requests of foreign retailers but also by their participation in scientific expeditions. The study of these two nineteenth-century, devoid artists of a properly academic formation, does not open a possibility of valuation for other artists who did not get to compete in European Halls and were either in its time very solicited like retratists.A lo largo del siglo XIX en la pintura latinoamericana se introducen varios temas nuevos, entre ellos el paisaje, ya no más como escenario de escenas patrióticas, religiosas o costumbristas. El modelo propuesto por Alejandro de Humboldt en su libro Vue des cordillères et monuments des peuples indigènes de l’Amérique, de 1810, para el estudio científico del paisaje, va a ser seguido no sólo por artistas alemanes, sino por nacionales como Carmelo Fernández Páez y Ramón Bolet Peraza quienes abordarán modestamente en su obra a la acuarela y al temple. El primero en su carácter de ilustrador de la labor geográfica de Agustín Codazzi, tanto en Venezuela como en Colombia, el segundo al atender solicitudes de comerciantes extranjeros pero también por su participación en expediciones científicas. El estudio de estos dos artistas decimonónicos, carentes de una formación propiamente

  15. THE MISSING EARTHQUAKES OF HUMBOLDT COUNTY: RECONCILING RECURRENCE INTERVAL ESTIMATES, SOUTHERN CASCADIA SUBDUCTION ZONE

    Science.gov (United States)

    Patton, J. R.; Leroy, T. H.

    2009-12-01

    transects are located in each of eight archival domains in order to evaluate archival bias and potential deformation sources for the southern Cascadia subduction zone. These domains are located in the Eel River, Humboldt Bay, Humboldt Lagoons, and Crescent City regions. In any given domain, evidence of earthquakes can be regional, local, or both. Core transects are designed to capture archival bias due to 1) interseismic deformation in the upper plate or the megathrust, 2) rupture on upper plate thrust faults, 3) rupture on the megathrust, or 4) rupture on both. Modern biogeochemical transects are used to calibrate paleontologic estimates. Based on our assessment, we determine which sites need better age control, which sites need supplemental coring, and key new research areas that need to be investigated.

  16. Data on Streamflow and Quality of Water and Bottom Sediment in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1998-2000

    Science.gov (United States)

    Paul, Angela P.; Thodal, Carl E.

    2003-01-01

    This study was initiated to expand upon previous findings that indicated concentrations of dissolved solids, arsenic, boron, mercury, molybdenum, selenium, and uranium were either above geochemical background concentrations or were approaching or exceeding ecological criteria in the lower Humboldt River system. Data were collected from May 1998 to September 2000 to further characterize streamflow and surface-water and bottom-sediment quality in the lower Humboldt River, selected agricultural drains, Upper Humboldt Lake, and Lower Humboldt Drain (ephemeral outflow from Humboldt Sink). During this study, flow in the lower Humboldt River was either at or above average. Flows in Army and Toulon Drains generally were higher than reported in previous investigations. An unnamed agricultural drain contributed a small amount to the flow measured in Army Drain. In general, measured concentrations of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium were higher in water from agricultural drains than in Humboldt River water during this study. Mercury concentrations in water samples collected during the study period typically were below the laboratory reporting level. However, low-level mercury analyses showed that samples collected in August 1999 from Army Drain had higher mercury concentrations than those collected from the river or Toulon Drain or the Lower Humboldt Drain. Ecological criteria and effect concentrations for sodium, chloride, dissolved solids, arsenic, boron, mercury, and molybdenum were exceeded in some water samples collected as part of this study. Although water samples from the agricultural drains typically contained higher concentrations of sodium, chloride, dissolved solids, arsenic, boron, and uranium, greater instantaneous loads of these constituents were carried in the river near Lovelock than in agricultural drains during periods of high flow or non-irrigation. During this study, the high flows in the lower Humboldt River

  17. Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

    Science.gov (United States)

    Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

    2018-03-01

    In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 μΦ_0/Hz^{1/2}.

  18. Second order gradiometer and dc SQUID integrated on a planar substrate

    Science.gov (United States)

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

    1985-02-01

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

  19. Second order gradiometer and dc SQUID integrated on a planar substrate

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-02-15

    An integrated system of a thin-film niobium dc superconducting quantum interference device (SQUID) and a second order gradiometer on a planar substrate is described. The system consists of a dc SQUID with eight loops in parallel, each sensitive to the second derivative partial/sup 2/B/sub z//partialx/sup 2/ of the magnetic field. The calculated SQUID inductance is 1.3 nH. With an overall size of 16 x 16.5 mm/sup 2/ a sensitivity of 1.5 x 10/sup -9/ Tm/sup -2/ Hz/sup -1//sup ///sup 2/ is obtained. The measured transfer function for uniform fields perpendicular to the plane of the gradiometer is 2.1 x 10/sup -7/ T Phi/sup -1//sub 0/.

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

    Science.gov (United States)

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

    2017-11-01

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

  1. A SQUID magnetometry system for a cryogenic neutron electric dipole moment experiment

    Energy Technology Data Exchange (ETDEWEB)

    Henry, S., E-mail: s.henry@physics.ox.ac.uk; Clarke, C.; Cottle, A.; Lynch, A.; Pipe, M.

    2014-11-01

    Precision magnetometry is an essential component of any neutron electric dipole moment experiment in order to correct shifts in the neutron precession frequency due to changes in the magnetic field. We have developed a magnetometry system using 12 SQUID sensors, designed to operate in 0.5 K superfluid helium. The pick-up loops located near the neutron cell are connected to the SQUID sensors by ∼2 m twisted wire pairs. The SQUID readout cables are run via an intermediate stage at 4.2 K. The system has been installed and tested in the cryoEDM apparatus at the ILL, Grenoble, and used to characterise the magnetic environment. Further tests in a suitable low noise environment confirm it meets our requirements.

  2. Squid measurement of the Verwey transition on epitaxial (1 0 0) magnetite thin films

    International Nuclear Information System (INIS)

    Dediu, V.; Arisi, E.; Bergenti, I.; Riminucci, A.; Solzi, M.; Pernechele, C.; Natali, M.

    2007-01-01

    We report results on epitaxial magnetite (Fe 3 O 4 ) thin films grown by electron beam ablation on (1 0 0) MgAl 2 O 4 substrates. At 120 K magnetite undergoes a structural and electronic transition, the so-called Verwey transition, at which magnetic and conducting properties of the material change. We observed the Verwey transition on epitaxial films with a thickness of 50 nm by comparing zero-field cooling (ZFC) and field cooling (FC) curves measured with a superconducting quantum interference device (SQUID) magnetometer. Observation of the Verwey transition by SQUID measurements in the films is sign of their high crystalline quality. Room temperature ferromagnetism has also been found by magneto-optical Kerr rotation (MOKE) and confirmed by SQUID measurements, with a hysteresis loop showing a coercive field of hundreds of Oe

  3. Direct readout flux locked loop circuit with automatic tuning of bias current and bias flux for high-Tc SQUID

    International Nuclear Information System (INIS)

    Hirano, T.; Nagaishi, T.; Itozaki, H.

    1999-01-01

    Measurement of high-frequency magnetic signals has been required from some SQUID applications. We fabricated a high-T c SQUID magnetic sensor system that can treat high-frequency signals. This system is composed of a SQUID, a preamplifier circuit, a flux locked loop (FLL) circuit with I/O and a personal computer and a PC card. We used the FLL circuit with no modulation to treat the high-frequency signal and to simplify the circuit. This system can treat a signal from dc to 1 MHz. All the sequence from tuning the SQUID to data acquisition can be done by a personal computer. This system successfully realized easy operation of SQUID measurement. (author)

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lu, D.F.; Fan, C.; Ruan, J.Z. [Midwest Superconductivity Inc., Lawrence, KS (United States)] [and others

    1994-12-31

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

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  7. Axon-Schwann cell interaction in the squid nerve fibre.

    Science.gov (United States)

    Villegas, J

    1972-09-01

    The electrical properties of Schwann cells and the effects of neuronal impulses on their membrane potential have been studied in the giant nerve fibre of the squid.1. The behaviour of the Schwann cell membrane to current injection into the cell was ohmic. No impulse-like responses were observed with displacements of 35 mV in the membrane potential. The resistance of the Schwann cell membrane was found to be approximately 10(3) Omega cm(2).2. A long-lasting hyperpolarization is observed in the Schwann cells following the conduction of impulse trains by the axon. Whereas the propagation of a single impulse had little effect, prolonged stimulation of the fibre at 250 impulses/sec was followed by a hyperpolarization of the Schwann cell that gradually declined over a period of several minutes.3. The prolonged effects of nerve impulse trains on the Schwann cell were similar to those produced by depolarizing current pulses applied to the axon by the voltage-clamp technique. Thus, a series of depolarizing pulses in the axon was followed by a long-lasting hyperpolarization of the Schwann cells. In contrast, the application of a series of hyperpolarizing 100 mV pulses at a frequency of 1/sec had no apparent effects.4. Changes in the external potassium concentration did not reproduce the long-lasting effects of nerve excitation.5. The hyperpolarizing effects of impulse trains were abolished by the incubation of the nerve fibre in a sea-water solution containing trypsin.6. These findings are discussed in relation to the possible mechanisms that might be responsible for the long-lasting hyperpolarizations of the Schwann cells.

  8. Quantum decay of metastable current states in rf squids

    International Nuclear Information System (INIS)

    Dmitrenko, I.M.; Khlus, V.A.; Tsoj, C.M.; Shnyrkov, V.I.

    1985-01-01

    Quantum decay of metastable current states in a rf SQUID superconducting ring of a hysteresis mode are considered. Point contacts are used as a Josephson weak link. The first derivative of rf IVC, dVsub(T)/dIsub(RF), is measured which gives the dependence of the density of decay probability on the amplitude of magnetic flux oscillations in the ring. The temperature dependence of probability distribution width between 4.2 and 0.5 K suggests that for most of high-ohmic contacts Nb-Nb, Nb-Ag-Nb the quantum mechanisms of decay become dominant beginning with the temperature of about 2 K. The experimental parameters of distribution of decay probability in the quantum limit are compared to those calculated by the theory of macroscopic quantum tunneling in the limit of high and low dissipation. The experimental values of probability density distribution width and characteristic quantum temperature are higher than the theoretical ones, the fact can be attributed to the deviation of current-phase relation of contact from a sinusoidal one. Besides, some contacts seem to correspond to the case of an intermediate value of dissipation. As the frequency of rf oscillations varies from 30 to 6 MHz, the distribution width remains unchanged in accordance with the theory of quantum tunneling decay of metastable current state in the ring in the limit of high damping. At low temperatures (T approximately 0.5 K), and rather small damping coefficient, the density of probability displays anomalous peaks when the amplitude of rf oscillations is lower considerably than the critical vaiue of magnetic flux in the ring

  9. Detection of thermal aging degradation and plastic strain damage for duplex stainless steel using SQUID sensor

    International Nuclear Information System (INIS)

    Otaka, M.; Evanson, S.; Hesegawa, K.; Takaku, K.

    1991-01-01

    An apparatus using a SQUID sensor is developed for nondestructive inspection. The measurements are obtained with the SQUID sensor located approximately 150 mm from the specimen. The degradation of thermal aging and plastic strain for duplex stainless steel is successfully detected independently from the magnetic characterization measurements. The magnetic flux density under high polarizing field is found to be independent of thermal aging. Coercive force increases with thermal aging time. On the other hand, the magnetic flux density under high field increases with the plastic strain. Coercive force is found to be independent of the plastic strain. (author)

  10. From Wilhelm von Humboldt to Hitler-are prominent people more prone to have Parkinson's disease?

    Science.gov (United States)

    Horowski; Horowski; Calne; Calne

    2000-10-01

    We describe Parkinsonism in prominent people, where Wilhelm von Humboldt and Adolf Hitler provide just two spectacular, opposing examples. In both of them, there is little if any evidence that the disease did influence their life ambitions, methods of achieving them or cognitive function in general. Thus, Hitler's Parkinsonism should remain a 'footnote' to history, and historians should acknowledge that in his last years, his trembling, his curbed posture, his slow walking, mask-like face and low voice did not indicate remorse, fear or depression as a consequence of his crimes, but were mere expressions of his disease which, until the end, had no impact on his intellectual skills and methods. The apparently higher incidence of Parkinsonism in prominent people may be just due to their higher visibility, or a consequence of disease-related personality traits (e.g. ambition, perfectionism, rigidity) which may contribute to becoming, e.g., a prominent authoritarian person. Perhaps even some early behaviour pattern (such as repressed emotions or acting in public-which could even increase the risk of some infection) contributes to a greater vulnerability for developing Parkinsonism. Further studying other prominent cases might lead us to better understanding of risk factors and the expression of early Parkinsonism.

  11. Investigation of Spatial Variation of Sea States Offshore of Humboldt Bay CA Using a Hindcast Model.

    Energy Technology Data Exchange (ETDEWEB)

    Dallman, Ann Renee; Neary, Vincent Sinclair

    2014-10-01

    Spatial variability of sea states is an important consideration when performing wave resource assessments and wave resource characterization studies for wave energy converter (WEC) test sites and commercial WEC deployments. This report examines the spatial variation of sea states offshore of Humboldt Bay, CA, using the wave model SWAN . The effect of depth and shoaling on bulk wave parameters is well resolved using the model SWAN with a 200 m grid. At this site, the degree of spatial variation of these bulk wave parameters, with shoaling generally perpendicular to the depth contours, is found to depend on the season. The variation in wave height , for example, was higher in the summer due to the wind and wave sheltering from the protruding land on the coastline north of the model domain. Ho wever, the spatial variation within an area of a potential Tier 1 WEC test site at 45 m depth and 1 square nautical mile is almost negligible; at most about 0.1 m in both winter and summer. The six wave characterization parameters recommended by the IEC 6 2600 - 101 TS were compared at several points along a line perpendicular to shore from the WEC test site . As expected, these parameters varied based on depth , but showed very similar seasonal trends.

  12. La fabrique du savoir Essai sur les carnets de voyage d'Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Marie-Noëlle Bourguet

    2006-10-01

    Full Text Available Article in French, Abstract in English.Whilst the notebook belongs to the imagery of the enlightened scientist's persona (an auxiliary tool kept by his side to be hastily scribbled with data, when at the bench or in the field, it has been given little attention by historians of science, who are used to consider its manuscript pages as a documentary resource to complement the printed text, but rarely take the notebook as a material and cultural object by itself, the history and epistemology of which is to be explored. Only recently have new trends in the historiography, by historians of printed books and reading practices, and by social and cultural historians of knowledge, called for a fresh look and opened the way for new approaches. Taking Alexander von Humboldt as a paramount example, who expressly devoted his life to "observing and recording" the world, pen in hand, this paper explores the note-taking practices at work in his travel diaries and notebooks from the perspective of the history of scientific observation and cognitive practices. Four themes are successively considered : the question of method and apprenticeship ; the timing of note-taking practices ; the nature and status of the data jotted down on the page ; finally, their uses in the production of scientific knowledge. In the back and forth movement between the observation of the world and the writing of science, the notebook stood as a crucial intellectual step and cognitive tool.

  13. The Humboldt Penguin (Spheniscus humboldti) Rete Tibiotarsale - A supreme biological heat exchanger.

    Science.gov (United States)

    Kazas, Shaked; Benelly, Moran; Golan, Saar

    2017-07-01

    Humans are unable to survive low temperature environments without custom designed clothing and support systems. In contrast, certain penguin species inhabit extremely cold climates without losing substantial energy to self-heating (emperor penguins ambient temperature plummets to as low as -45°C). Penguins accomplish this task by relying on distinct anatomical, physiological and behavioral adaptations. One such adaptation is a blood vessel heat exchanger called the 'Rete Tibiotarsale' - an intermingled network of arteries and veins found in penguins' legs. The Rete existence results in blood occupying the foot expressing a lower average temperature and thus the penguin loosing less heat to the ground. This study examines the Rete significance for the species thermal endurance. The penguin anatomy (leg and main blood vessels) is reconstructed using data chiefly based on the Humboldt species. The resulting model is thermally analyzed using finite element (COMSOL) with the species environment used as boundary conditions. A human-like blood vessel configuration, scaled to the penguin's dimensions, is used as a control for the study. Results indicate that the Rete existence facilitates upkeep of 25-65% of the species total metabolic energy production as compared with the human-like configuration; thus making the Rete probably crucial for penguin thermal endurance. Here, we quantitatively link for the first time the function and structure of this remarkable physiological phenotype. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Revisiting Peruvian anchovy ( Engraulis ringens) trophodynamics provides a new vision of the Humboldt Current system

    Science.gov (United States)

    Espinoza, Pepe; Bertrand, Arnaud

    2008-10-01

    The Peruvian anchovy or anchoveta ( Engraulis ringens) forages on plankton and is a main prey for marine mammals, seabirds, fish, and fishers, and is therefore a key element of the food web in the Humboldt Current system (HCS). Here, we present results from the analysis of 21,203 anchoveta stomach contents sampled during 23 acoustic surveys over the period 1996-2003. Prey items were identified to the genus level, and the relative dietary importance of different prey was assessed by determination of their carbon content. Variability in stomach fullness was examined relative to the diel cycle, the distance from the coast, sea surface temperature, and latitude, using generalized additive models (GAMs). Whereas phytoplankton largely dominated anchoveta diets in terms of numerical abundance and comprised >99% of ingested prey items, the carbon content of prey items indicated that zooplankton was by far the most important dietary component, with euphausiids contributing 67.5% of dietary carbon followed by copepods (26.3%). Stomach fullness data showed that anchoveta feed mainly during daytime between 07h00 and 18h00, although night-time feeding also made a substantial contribution to total food consumption. Stomach fullness also varied with latitude, distance from the coast, and temperature, but with substantial variability indicating a high degree of plasticity in anchoveta feeding behaviour. The results suggest an ecological role for anchoveta that challenges current understanding of its position in the foodweb, the functioning of the HCS, and trophic models of the HCS.

  15. Safstor decommissioning of the Humboldt Bay Power Plant Unit No. 3

    International Nuclear Information System (INIS)

    Nelson, R.T.

    1985-01-01

    The Humboldt Bay Power Plant is located near Eureka, California, about 265 miles north of San Francisco. The plant consists of two fossil fueled units, two mobil gas turbine peaking units, and a nuclear unit - Unit No. 3. Unit No. 3, which utilized a boiling water reactor, was constructed between 1960 and 1963. The unit began commercial operation in August 1963 and operated until July 2, 1976 when it was shutdown for refueling, seismic modifications, and additional seismic and geologic studies. During the years Unit 3 operated it had one of the best operating records of any nuclear power plant in the United States. For its operating lifetime Unit 3 had an overall capacity factor of 63.0% and an availability factor of 85.9%. The unit included certain design features which made it unique among nuclear power plants of its era. Some of these unique features included natural circulation recirculation flow which eliminated the need for costly recirculation pumps, utilization of a pressure suppression containment system which had been developed jointly by PG and E and the General Electric Company, and the fact that the reactor vessel and the containment system were constructed in a caisson below ground level. These design features reduced the overall construction cost of the unit and improved its inherent safety

  16. En el reino de la ambivalencia. La Cuba de Alejandro de Humboldt

    Directory of Open Access Journals (Sweden)

    Oliver Lubrich

    2001-04-01

    Full Text Available Article in Spanish, Abstracts in English and German.In the Realm of Ambivalence.The Question of Cuba in Alexander von Humboldt’s American TravelogueCuba has a special role in Alexander von Humboldt’s American travel narrative: Humboldt’s experience of colonial slave economy drives his optimistic philosophy, inspired by European Enlightenment, into a crisis, and brings to surface the inherent contradictions of his discourse. This phenomenon is particularly interesting from the perspective of literary criticism: Alexander von Humboldt conceives Cuba as a poetic space, where contradictions and ambivalences coexist. Already on the boat to the island from Venezuela he creates destablizing effects of sensual perceptions. He stages his landing in Havana as a moment of oppositional impressions. Within the symbolic topography of his geographic fantasy, Cuba functions as an imaginary in-between space. And Humboldt’s philosophical and aesthetic terminology undergoes a semantic recoding in Cuba: what was once used in a philosophical and aesthetic sense, now has become charged with an economic and political meaning.

  17. Verification of the weak equivalence principle of supports and heavy masses using SQUIDs; Ueberpruefung des schwachen Aequivalenzprinzips von Traegern und schwerer Masse mittels Squids

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R. [Friedrich-Schiller-Universitaet Jena (Germany). Inst. fuer Festkoerperphysik; Dittus, H. [Univ. Bremen (Germany). Zentrum fuer angewandte Raumfahrttechnologie und Mikrogravitation

    2003-07-01

    The weak equivalence principle is one of the fundamental hypotheses of general relativity and one of the key elements of our physical picture of the world, but since Galileo there has been no satisfactory way of verifying it. The new SQUID technology may offer a solution. The contribution presents the experiments of Jena University. Applications are envisaged, e.g., in the STEP space mission of the NASA/ESA. [German] Das Schwache Aequivalenzprinzip ist eine der grundlegenden Hypothesen der Allgemeinen Relativitaetstheorie und damit einer der Grundpfeiler unseres physikalischen Weltbildes. Obwohl es seit den ersten Experimenten von Galileo Galilei am Schiefen Turm zu Pisa im Jahre 1638 bis heute schon zahlreiche und immer praeziser werdende Messungen zur Ueberpruefung der Aequivalenz von schwerer und traeger Masse gegeben hat, ist die strenge Gueltigkeit dieses fundamentalen Prinzips experimentell vergleichsweise unzureichend bestimmt. Neuere Methoden, wie der Einsatz SQUID-basierter Messtechnik und die Durchfuehrung von Experimenten auf Satelliten, lassen Verbesserungen schon in naher Zukunft erwarten, so dass theoretische Ueberlegungen zur Vereinigung aller uns bekannten physikalischen Wechselwirkungen, die eine Verletzung des Schwachen Aequivalenzprinzips voraussagen, experimentell eingegrenzt werden koennten. Der Beitrag gibt einen Ueberblick ueber die an der Universitaet Jena entwickelte SQUID-basierte Messtechnik zum Test des Aequivalenzprinzips und fasst die bisher bei Freifallversuchen am Fallturm Bremen erzielten experimentellen Ergebnisse zusammen. Ein Ausblick auf die geplante Raumfahrtmission STEP der NASA/ESA zum Praezisionstest des Schwachen Aequivalenzprinzips schliesst den Beitrag ab. (orig.)

  18. Experiment und Wissensvermittlung. Alexander von Humboldts Darstellungsmethoden in seinen Versuchen über die gereizte Muskel- und Nervenfaser

    Directory of Open Access Journals (Sweden)

    Alexander Stöger

    2016-11-01

    Full Text Available Zusammenfassung Alexander von Humboldt hat sich in jungen Jahren mit galvanischen Experimenten beschäftigt und die Resultate in einem umfassenden, zweibändigen Werk publiziert. Dabei zeigte er nicht nur, dass er als Experimentator und Teil der wissenschaftlichen Gemeinschaft fähig war, sich mit einem so neuen und komplexen Phänomen zu beschäftigen. Es lässt sich auch erkennen, dass er bereits in dieser frühen Schrift versuchte, das umfangreiche Wissen dem Leser zugänglich zu machen. Der Artikel betrachtet Humboldts Galvanismusschrift Versuche über die gereizte Muskel- und Nervenfaser (1797–1798 und untersucht einige Elemente wie Anhänge und Schreibstil, die Humboldt nutzte, um die umfangreichen Informationen zu ordnen und dem Leser so neben den Big Data seiner Erkenntnisse auch passende Suchfunktionen zur Verfügung zu stellen, die eine gezielte Nutzung überhaupt ermöglichen.  Abstract In the early stages of his scientific career, Alexander von Humboldt took an interest in experiments in galvanism. He publicised the results in a two-volume work under the title Versuche über die gereizte Muskel- und Nervenfaser (Experiments on the Stimulated Muscle and Nerve Fibre in 1797 and 1798. In this treatise, he presented himself as competent experimenter and member of the scientific community, but also demonstrated that he was capable of researching new and complex phenomena. These volumes also provide insight into his early attempts to facilitate the readers’ access to the extensive information he had compiled. This article analyses some aspects of Humboldt’s efforts to arrange his vast numbers of observations and theories, for example by means of appendices and narrative style, which he used not only to present the resulting big data collected during his research, but also to make it possible for the reader to organise and utilise this data.   Resumen A temprana edad Alexander von Humboldt se dedicó a galvanismo. En 1797 y 1798

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

    Science.gov (United States)

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

    2009-01-01

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

  20. Effects of Gamma Irradiation on Shelf-Life and Sensory Scores of Squid Sundae under Accelerated Storage Conditions

    International Nuclear Information System (INIS)

    Kim, H.J.; Kim, K.B.W.R.; Kim, D.H.; Sunwoo, C.; Jung, S.A.; Jeong, D.H.; Jung, H.Y.; Ahn, D.H.; Kim, J.H.; Lee, J.W.; Do, S.R.; Byun, M.W.

    2012-01-01

    This study was conducted to examine the effects of gamma irradiation on the shelf-life and sensory scores of squid Sundae under accelerated storage conditions. Squid Sundae was stored at 37°C for 35 days following gamma irradiation at doses of 0, 10, and 20 kGy. For total viable cell counts, control and gamma-irradiated (GI) (10 kGy) squid Sundae were already spoiled in 4 days, whereas GI (20 kGy) squid Sundae showed complete suppression of bacterial growth during storage. There were no significant changes in pH values compared to the control. The VBN and TBARS (thiobarbituric acid reactive substance) values of GI (20 kGy) squid Sundae were significantly lower than those of the control. In addition, the induction period of GI (20 kGy) squid Sundae as measured by a Rancimat showed a higher level compared to that of the control. In the sensory evaluation, there were no significant changes between the control and GI samples. These results suggest that a dose of 20 kGy is the optimum and effective dose for preservation of squid Sundae. (author)

  1. Alexander von Humboldt und Carlos Montúfar als Reisegefährten: ein Vergleich ihrer Tagebücher zum Chimborazo-Aufstieg

    Directory of Open Access Journals (Sweden)

    Reinhard Andress

    2011-03-01

    Full Text Available ZusammenfassungAls Alexander von Humboldt im Juni 1802 von Quito aus zum Rest seiner lateinamerikanischen Forschungsreise aufbrach, begleitete ihn, abgesehen von Aimé Bonpland, Carlos Montúfar bis nach Europa zurück begleitet, u.a. auch auf beim Versuch, den Chimborazo zu ersteigen. Bis kurz vor der Stadt Cajamarca im heutigen Peru schrieb Montúfar ein relativ unbekanntes Tagebuch zur Reise. Nach einem kurzen Ausflug in das Leben von Humboldts Begleiter steht im Zentrum der weiteren Ausführungen die Frage, ob sein Tagebuch ein anderes Licht auf Humboldt und speziell auf den Aufstiegsversuch wirft. Das läuft auf einen Vergleich der Tagebücher der beiden Reisegefährten hinaus und auf den Versuch, die scheinbaren Widersprüche aufzulösen.AbstractWhen Alexander von Humboldt left Quito in June 1802 in order to undertake the rest of his Latin-American trip of exploration, he was accompanied, aside from Aimé Bonpland, by Carlos Montúfar all the way back to Europe, including the attempt to scale the Chimborazo. Up to shortly before the city of Cajamarca in today’s Peru, Montúfar wrote an relatively unknown diary account of their travels. After a brief excursion into the life of Humboldt’s companion, the question is considered whether his diary sheds a different light on Humboldt and specifically on the mountain climb. That amounts to a comparison of the diaries of the two travel companions and to an attempt to explain the apparent contradictions.ResumenCuando Alexander von Humboldt salió de Quito en junio de 1802 para continuar con el resto de su viaje de exploración por la América Latina, fue acompañado por Carlos Montúfar además de Aimé Bonpland hasta que volvieron a Europa. Este trayecto incluía la tentativa de llegar a la cima del Chimborazo. Hasta un poco antes de la cuidad de Cajamarca que está en el Perú de hoy día, Montúfar mantenía un diario relativamente no conocido del viaje. Después de una breve excursión por

  2. Transatlantic communication in the 19th century aspects of the correspondence between alexander von humboldt and george ticknor

    Directory of Open Access Journals (Sweden)

    Schwarz, Ingo

    2004-12-01

    Full Text Available The Prussian explorer Alexander von Humboldt (1769-1859 and the North American scholar George Ticknor (1791-1871 met in 1817 in Paris, after Ticknor had studied languages, history, and natural sciences at the University of Göttingen. Two years later, he became the first Harvard Professor of the French and Spanish Languages and Literatures. When Ticknor visited Europe in 1836 and 1856, Humboldt was his guide in the Prussian Capital. Both, Humboldt and Ticknor were mediators between the Old World and the New Continent at a time when nationalism was fashionable both in literature and in politics. Humboldt and Ticknor did not agree on all political questions. However, their respect for each other helped them avoid controversial topics in their correspondence, and possibly in their conversations. With their ability to rank the things they had in common higher than their differences they were able to maintain a fruitful transatlantic dialogue over forty years.

    El explorador prusiano Alexander von Humboldt (1769-1859 y el erudito norteamericano George Ticknor (1791-1871 se conocieron en 1817 en París, después que Ticknor había estudiado idiomas, historia y ciencias naturales en la Universidad de Göttingen. Dos años más tarde, llegó a ser el primer Profesor Harvard de Lenguas y Literatura francesa y española. Cuando Ticknor visitó Europa en 1836 y 1856, Humboldt fue su guía en la capital prusiana. Humboldt y Ticknor fueron mediadores entre el Viejo Mundo y el Nuevo Continente en una época en que el nacionalismo estaba de moda en la literatura y la política. Humboldt y Ticknor no estaban de acuerdo en todas las cuestiones políticas. Sin embargo, el respecto que existía entre ellos evitó los asuntos controvertibles en su conversación y posiblemente en su correspondencia. Con su habilidad para clasificar las cosas tenían en común por encima de sus diferencias ser capaces de mantener un diálogo fructífero trasatlántico durante

  3. Expression of squid iridescence depends on environmental luminance and peripheral ganglion control.

    Science.gov (United States)

    Gonzalez-Bellido, P T; Wardill, T J; Buresch, K C; Ulmer, K M; Hanlon, R T

    2014-03-15

    Squid display impressive changes in body coloration that are afforded by two types of dynamic skin elements: structural iridophores (which produce iridescence) and pigmented chromatophores. Both color elements are neurally controlled, but nothing is known about the iridescence circuit, or the environmental cues, that elicit iridescence expression. To tackle this knowledge gap, we performed denervation, electrical stimulation and behavioral experiments using the long-fin squid, Doryteuthis pealeii. We show that while the pigmentary and iridescence circuits originate in the brain, they are wired differently in the periphery: (1) the iridescence signals are routed through a peripheral center called the stellate ganglion and (2) the iridescence motor neurons likely originate within this ganglion (as revealed by nerve fluorescence dye fills). Cutting the inputs to the stellate ganglion that descend from the brain shifts highly reflective iridophores into a transparent state. Taken together, these findings suggest that although brain commands are necessary for expression of iridescence, integration with peripheral information in the stellate ganglion could modulate the final output. We also demonstrate that squid change their iridescence brightness in response to environmental luminance; such changes are robust but slow (minutes to hours). The squid's ability to alter its iridescence levels may improve camouflage under different lighting intensities.

  4. Effect of electron beam on the microbiological and sensory characteristics of squid jeotkal and its ingredients

    International Nuclear Information System (INIS)

    Liu Xiande; Piao Linghua

    2012-01-01

    A seasoned squid Jeotkal, Koran traditional fermented seafood, and its ingredients for manufacturing, including red hot pepper powder and ground garlic were irradiated by 0, 0.5, 1, 2 and 5 kGy electron beam and stored at 4 ℃ for 4 weeks to determine the changes of microorganisms and sensory characteristics. The initial contamination of squid Jeotkal such as total aerobic bacteria, yeast and mold, and coliform bacterial were at the levels of 2.88, 3.04 and 4.20 logCFU/g, respectively. However, 5 kGy electron beam irradiation reduced the total aerobic bacteria about 1 logCFU/g. Yeast and mold and coliform bacterial were reduced 1 ∼ 2 logCFU/g after 2 kGy irradiation and reached to undetected level when the sample was irradiated at 5 kGy and following storage at 4 ℃ for 4 weeks. Sensory characteristics showed that 5 kGy electron beam irradiation did not adversely affect overall acceptability of squid Jeotkal and its ingredients during 4 ℃ storage. Therefore, electron beam irradiation is one of the possible methods to improve storage stability of seasoned squid Jeotkal. (authors)

  5. Highly balanced gradiometer systems based on HTS-SQUIDs for the use in magnetically unshielded environment

    NARCIS (Netherlands)

    Borgmann, H.J.R.; Rijpma, A.P.; ter Brake, Hermanus J.M.; Rogalla, Horst; David, P.

    1999-01-01

    Two different concepts for gradiometer formation were tested applying high-temperature rf SQUIDs operated at 77 K in liquid nitrogen. All gradiometer systems are fully based on magnetometers. The first concept applies a compensating magnetometer at different positions to actively cancel the magnetic

  6. Integrated de SQUID magnetometer with high dV/dB

    International Nuclear Information System (INIS)

    Drung, D.; Cantor, R.; Peters, M.; Ryhanen, T.; Kochi, H.

    1991-01-01

    This paper presents a directly coupled dc SQUID magnetometer with very simple feedback electronics. The magnetometer has been integrated on a 7.2 x 7.2 mm 2 chip and fabricated using a four-level Nb/Si x N v /Nb process. Eight pick-up loops are connected in parallel to directly form the SQUID inductance of about 0.4 nH which leads to a high sensitivity B/Φ = 0.47 nT/Φ. An Additional Positive Feedback (APF) circuit on the magnetometer chip has been used to increase the gradient of the V-μ characteristic to dV/dΦ ≅ 300 μV/Φ 0 at the SQUID operating point. The resulting gradient of the transfer function of dV/dB ≅ 640 μV/nT makes it possible to directly read out the SQUID without helium temperature impedance matching circuits or flux modulation techniques

  7. Magnetic properties of thin Ni films measured by a dc SQUID-based magnetic microscope

    DEFF Research Database (Denmark)

    Snigirev, O.V.; Andreev, K.E.; Tishin, A.M.

    1997-01-01

    We have applied a scanning HTS (high-temperature superconductor) de SQUID (superconducting quantum interference device) -based magnetic microscope to study the magnetic properties of Au/Ni/Si(100) films in the thickness range from 8 to 200 Angstrom at T = 77 K. A one-domain structure with in...

  8. The effects of jig color and lunar bright on coastal squid jigging ...

    African Journals Online (AJOL)

    Squid jigging experiments were carried out to determine whether differences occurred between different colors and lunar brightness in Middle Eastern coast of Aegean Sea. Five different colors of jigs (red, blue, green, orange and white) were used together in same angle. According to one-way analysis of variance results, ...

  9. Rotational population patterns and searches for the nuclear SQUID (Superconducting Quantum Interference Device)

    International Nuclear Information System (INIS)

    Canto, L.F.; Donangelo, R.J.; Farhan, A.R.; Guidry, M.W.; Rasmussen, J.O.; Ring, P.; Stoyer, M.A.

    1989-11-01

    This paper presents new theoretical results for rotational population patterns in the nuclear SQUID effect. (The term nuclear SQUID is in analogy to the solid-state Superconducting Quantum Interference Devices.) The SQUID effect is an interesting new twist to an old quest to understand Coriolis anti-pairing (CAP) effects in nuclear rotational bands. Two-neutron transfer reaction cross sections among high-spin states have long been touted as more specific CAP probes than other nuclear properties. Heavy projectiles like Sn or Pb generally are recommended to pump the deformed nucleus to as high spin as possible for transfer. The interference and sign reversal of 2n transfer amplitudes at high spin, as predicted in the early SQUID work imposes the difficult requirement of Coulomb pumping to near back-bending spins at closest approach. For Pb on rare earths we find a dramatic departure from sudden-approximation, so that the population depression occurs as low as final spin 10h. 14 refs., 8 figs

  10. High-Tc SQUID Application for Roll to Roll Metallic Contaminant Detector

    International Nuclear Information System (INIS)

    Tanaka, S.; Kitamura, Y.; Uchida, Y.; Hatsukade, Y.; Ohtani, T.; Suzuki, S.

    2012-01-01

    A sensitive eight-channel high-Tc Superconducting Interference Device (SQUID) detection system for magnetic contaminant in a lithium ion battery anode was developed. Finding ultra-small metallic foreign matter is an important issue for a manufacturer because metallic contaminants carry the risk of an internal short. When contamination occurs, the manufacturer of the product suffers a great loss from recalling the tainted product. Metallic particles with outer dimensions smaller than 100 microns cannot be detected using a conventional X-ray imaging system. Therefore, a highly sensitive detection system for small foreign matter is required. We have already developed a detection system based on a single-channel SQUID gradiometer and horizontal magnetization. For practical use, the detection width of the system should be increased to at least 65 mm by employing multiple sensors. In this paper, we present an 8-ch high-Tc SQUID roll-to-roll system for inspecting a lithium-ion battery anode with a width of 65 mm. A special microscopic type of a cryostat was developed upon which eight SQUID gradiometers were mounted. As a result, small iron particles of 35 microns on a real lithium-ion battery anode with a width of 70 mm were successfully detected. This system is practical for the detection of contaminants in a lithium ion battery anode sheet.

  11. Comparison live adult Artemia and squid meat on the growth of Penaeid shrimp Metapenaeus dobsoni (Miers)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T.; Royan, J.P.

    An experiment lasting 14 weeks was conducted to compare the efficiency of live adult Artemia with fresh squid meat on growth of penaeid shrimp Metapenaeus dobsoni. The shrimps were found actively feeding on live Artemia and grew 84% more than those...

  12. A simple method for checking the balance of gradiometers used with squids

    International Nuclear Information System (INIS)

    Eghrari, I.R.; Ribeiro, P.C.

    1978-11-01

    A simple technique for detecting the degree of balance of first order gradiometers before connecting them to the SQUID is described. The effect of thermal cycling on this balance is given for different materials used in the construction of the gradiometers [pt

  13. Ocean acidification responses in paralarval squid swimming behavior using a novel 3D tracking system

    KAUST Repository

    Zakroff, Casey J.; Mooney, T. Aran; Wirth, Colin

    2017-01-01

    . pealeii from eggs reared under chronic OA demonstrated measurable impairments to swimming activity and control. This required the development of a novel, cost-effective, and robust method for 3D motion tracking and analysis. Squid eggs were reared in pCO2

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

    Science.gov (United States)

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

    2017-06-01

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

  15. A nitrogen triple-point thermal storage unit for cooling a SQUID magnetometer

    NARCIS (Netherlands)

    Rijpma, A.P.; Meenderink, D.J.; Reincke, H.A.; Venhorst, G.C.F.; Holland, H.J.; Brake, ter H.J.M.

    2005-01-01

    In order to achieve turnkey operation, the use is planned of cryocoolers to cool a SQUID magnetometer system. To minimize the magnetical and mech. interference from the coolers, they are switched off during the actual measurements. Consequently, a thermal storage unit (TSU) is required with

  16. A nitrogen triple-point thermal storage unit for cooling a SQUID magnetometer

    NARCIS (Netherlands)

    Rijpma, A.P.; Meenderink, D.J.; Reincke, H.A.; Venhorst, G.C.F.; Venhorst, G.C.F.; Holland, Herman J.; ter Brake, Hermanus J.M.

    2005-01-01

    In order to achieve turnkey operation, we plan to use cryocoolers to cool a SQUID magnetometer system. To minimize the magnetical and mechanical interference from the coolers, we intend to switch them off during the actual measurements. Consequently, a thermal storage unit (TSU) is required with

  17. Closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer

    NARCIS (Netherlands)

    Bosch, van den P.J.; Holland, H.J.; Brake, ter H.J.M.; Rogalla, H.

    1994-01-01

    A closed-cycle gas flow system for cooling a high-crit. temp. d.c.-superconducting quantum interference device (SQUID) magnetometer by means of a cryocooler has been designed, constructed and tested. The magnetometer is aimed to measure heart signals with a sensitivity of 0.1 pT/Hz1/2. The required

  18. Analysis of metal catalyst content in magnetically filtered SWCNTs by SQUID magnetometry

    Czech Academy of Sciences Publication Activity Database

    Pacáková, Barbara; Komínková, Zuzana; Vejpravová, Jana; Kalbáč, Martin

    2015-01-01

    Roč. 50, č. 6 (2015), s. 2544-2553 ISSN 0022-2461 R&D Projects: GA ČR GAP204/10/1677 Institutional support: RVO:68378271 ; RVO:61388955 Keywords : single-wall carbon nanotubes * nanoparticles * magnetic filtration * SQUID Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.302, year: 2015

  19. Characterization of single-core magnetite nanoparticles for magnetic imaging by SQUID relaxometry

    International Nuclear Information System (INIS)

    Adolphi, Natalie L; Huber, Dale L; Monson, Todd C; Provencio, Paula P; Bryant, Howard C; Fegan, Danielle L; Tessier, Trace E; Flynn, Edward R; Lim, JitKang; Majetich, Sara A; Trujillo, Jason E; Lovato, Debbie M; Butler, Kimberly S; Larson, Richard S; Hathaway, Helen J

    2010-01-01

    Optimizing the sensitivity of SQUID (superconducting quantum interference device) relaxometry for detecting cell-targeted magnetic nanoparticles for in vivo diagnostics requires nanoparticles with a narrow particle size distribution to ensure that the Neel relaxation times fall within the measurement timescale (50 ms-2 s, in this work). To determine the optimum particle size, single-core magnetite nanoparticles (with nominal average diameters 20, 25, 30 and 35 nm) were characterized by SQUID relaxometry, transmission electron microscopy, SQUID susceptometry, dynamic light scattering and zeta potential analysis. The SQUID relaxometry signal (detected magnetic moment/kg) from both the 25 nm and 30 nm particles was an improvement over previously studied multi-core particles. However, the detected moments were an order of magnitude lower than predicted based on a simple model that takes into account the measured size distributions (but neglects dipolar interactions and polydispersity of the anisotropy energy density), indicating that improved control of several different nanoparticle properties (size, shape and coating thickness) will be required to achieve the highest detection sensitivity. Antibody conjugation and cell incubation experiments show that single-core particles enable a higher detected moment per cell, but also demonstrate the need for improved surface treatments to mitigate aggregation and improve specificity.

  20. Characterization of single-core magnetite nanoparticles for magnetic imaging by SQUID relaxometry

    Energy Technology Data Exchange (ETDEWEB)

    Adolphi, Natalie L [Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, NM 87131 (United States); Huber, Dale L; Monson, Todd C; Provencio, Paula P [Sandia National Laboratories, P. O. Box 5800, Albuquerque, NM 87185 (United States); Bryant, Howard C; Fegan, Danielle L; Tessier, Trace E; Flynn, Edward R [Senior Scientific, LLC, 11109 Country Club NE, Albuquerque, NM 87111 (United States); Lim, JitKang; Majetich, Sara A [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Trujillo, Jason E; Lovato, Debbie M; Butler, Kimberly S; Larson, Richard S [Department of Pathology, Cancer Research and Treatment Center, University of New Mexico, Albuquerque, NM 87131 (United States); Hathaway, Helen J, E-mail: NAdolphi@salud.unm.ed [Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM 87131 (United States)

    2010-10-07

    Optimizing the sensitivity of SQUID (superconducting quantum interference device) relaxometry for detecting cell-targeted magnetic nanoparticles for in vivo diagnostics requires nanoparticles with a narrow particle size distribution to ensure that the Neel relaxation times fall within the measurement timescale (50 ms-2 s, in this work). To determine the optimum particle size, single-core magnetite nanoparticles (with nominal average diameters 20, 25, 30 and 35 nm) were characterized by SQUID relaxometry, transmission electron microscopy, SQUID susceptometry, dynamic light scattering and zeta potential analysis. The SQUID relaxometry signal (detected magnetic moment/kg) from both the 25 nm and 30 nm particles was an improvement over previously studied multi-core particles. However, the detected moments were an order of magnitude lower than predicted based on a simple model that takes into account the measured size distributions (but neglects dipolar interactions and polydispersity of the anisotropy energy density), indicating that improved control of several different nanoparticle properties (size, shape and coating thickness) will be required to achieve the highest detection sensitivity. Antibody conjugation and cell incubation experiments show that single-core particles enable a higher detected moment per cell, but also demonstrate the need for improved surface treatments to mitigate aggregation and improve specificity.

  1. Conversion of Squid Pens to Chitosanases and Proteases via Paenibacillus sp. TKU042

    Directory of Open Access Journals (Sweden)

    Chien Thang Doan

    2018-03-01

    Full Text Available Chitosanases and proteases have received much attention due to their wide range of applications. Four kinds of chitinous materials, squid pens, shrimp heads, demineralized shrimp shells and demineralized crab shells, were used as the sole carbon and nitrogen (C/N source to produce chitosanases, proteases and α-glucosidase inhibitors (αGI by four different strains of Paenibacillus. Chitosanase productivity was highest in the culture supernatants using squid pens as the sole C/N source. The maximum chitosanase activity of fermented squid pens (0.759 U/mL was compared to that of fermented shrimp heads (0.397 U/mL, demineralized shrimp shells (0.201 U/mL and demineralized crab shells (0.216 U/mL. A squid pen concentration of 0.5% was suitable for chitosanase, protease and αGI production via Paenibacillus sp. TKU042. Multi-purification, including ethanol precipitation and column chromatography of Macro-Prep High S as well as Macro-Prep DEAE (diethylaminoethyl, led to the isolation of Paenibacillus sp. TKU042 chitosanase and protease with molecular weights of 70 and 35 kDa, respectively. For comparison, 16 chitinolytic bacteria, including strains of Paenibacillus, were investigated for the production of chitinase, exochitinase, chitosanase, protease and αGI using two kinds of chitinous sources.

  2. Characterization and demonstration results of a SQUID magnetometer system developed for geomagnetic field measurements

    Science.gov (United States)

    Kawai, J.; Miyamoto, M.; Kawabata, M.; Nosé, M.; Haruta, Y.; Uehara, G.

    2017-08-01

    We characterized a low temperature superconducting quantum interference device (SQUID) magnetometer system developed for high-sensitivity geomagnetic field measurement, and demonstrated the detection of weak geomagnetic signals. The SQUID magnetometer system is comprised of three-axis SQUID magnetometers housed in a glass fiber reinforced plastic cryostat, readout electronics with flux locked loop (FLL), a 24-bit data logger with a global positioning system and batteries. The system noise was approximately 0.2 pT √Hz- 1/2 in the 1-50 Hz frequency range. This performance was determined by including the thermal noise and the shielding effect of the copper shield, which covered the SQUID magnetometers to eliminate high-frequency interference. The temperature drift of the system was ˜0.8 pT °C- 1 in an FLL operation. The system operated for a month using 33 l liquid helium. Using this system, we performed the measurements of geomagnetic field in the open-air, far away from the city. The system could detect weak geomagnetic signals such as the Schumann resonance with sixth harmonics, and the ionospheric Alfvén resonance appearing at night, for the north-south and east-west components of the geomagnetic field. We confirm that the system was capable of high-sensitivity measurement of the weak geomagnetic activities.

  3. SQUIDs as detectors in a new experiment to measure the neutron electric dipole moment

    International Nuclear Information System (INIS)

    Espy, M.A.; Cooper, M.; Lamoreaux, S.; Kraus, R.H. Jr.; Matlachov, A.; Ruminer, P.

    1998-01-01

    A new experiment has been proposed at Los Alamos National Laboratory to measure the neutron electric dipole moment (EDM) to 4x10 -28 ecm, a factor of 250 times better than the current experimental limit. Such a measure of the neutron EDM would challenge the theories of supersymmetry and time reversal violation as the origin of the observed cosmological asymmetry in the ratio of baryons to antibaryons. One possible design for this new experiment includes the use of LTC SQUIDs coupled to large (∼100 cm 2 ) pick-up coils to measure the precision frequency of the spin-polarized 3 He atoms that act as polarizer, spin analyzer, detector, and magnetometer for the ultra-cold neutrons used in the experiment. The method of directly measuring the 3 He precession signal eliminates the need for very uniform magnetic fields (a major source of systematic error in these types of experiments). It is estimated that a flux of ∼2x10 -16 Tm 2 (0.1 Φ 0 ) will be coupled into the pick-up coils. To achieve the required signal-to-noise ratio one must have a flux resolution of dΦ SQ = 2x10 -6 Φ 0 /√Hz at 10 Hz. While this is close to the sensitivity available in commercial devices, the effects of coupling to such a large pick-up coil and flux noise from other sources in the experiment still need to be understood. To determine the feasibility of using SQUIDs in such an application the authors designed and built a superconducting test cell, which simulates major features of the proposed EDM experiment, and they developed a two-SQUID readout system that will reduce SQUID noise in the experiment. They present an overview of the EDM experiment with SQUIDs, estimations of required SQUID parameters and experimental considerations. The authors also present the measured performance of a single magnetometer in the test cell as well as the performance of the two SQUID readout technique

  4. Low-frequency noise in high-(Tc) superconductor Josephson junctions, SQUIDs, and magnetometers

    Science.gov (United States)

    Miklich, A. H.

    1994-05-01

    Design and performance of high-T(sub c) dc superconducting quantum interference devices (SQUID's), junctions that comprise them, and magnetometers made from them are described, with attention to sources of 1/f noise. Biepitaxial junctions are found to have large levels of critical current fluctuations which make them unsuitable for low-noise SQUID's; this suggests a poorly connected interface at the grain boundary junction. SQUID's from bicrystal junctions have levels of critical current noise controllable using bias current reversal techniques which leave the noise white down to frequencies of a few Hz. A SQUID with an energy resolution of 1.5 x 10(exp -30) J Hz(exp -1) at 1 Hz is reported. Magnetometers in which a (9 mm)(exp 2) pickup loop is directly coupled to a SQUID body have achieved field resolutions of 93 fT Hz(exp -1/2) down to frequencies below 1 Hz, improving to 39 fT Hz(exp -1/2) at 1 Hz with the addition of a 50mm-diameter single-turn flux transformer. Poor coupling to pickup loop makes it difficult to satisfy competing goals of high field resolution and small detector size necessary for multichannel biomagnetic imaging. Improved coupling is demonstrated by the use of multiturn-input-coil flux transformers, and a resolution of 35 fT Hz(exp -1/2) in the white noise region is reported with a (10 mm)(exp 2) pickup loop. However, additional 1/f noise from processed multilayer structures in the transformer limits the resolution at 1 Hz to 114 fT Hz(exp -1/2). High-T(sub c) SQUID's exhibit additional 1/f noise when cooled in a nonzero static magnetic field because of additional flux vortices trapped in the film, with the noise power at 1 Hz typically increasing by a factor of 10-20 in a field of 0.05mT (0.5 G). Finally, a SQUID-based voltmeter with a resolution of 9.2 pV Hz(exp -1/2) at 10 Hz (24 pV Hz(exp -1/2) at 1 Hz) is described.

  5. Low-Frequency Noise in High-T Superconductor Josephson Junctions, Squids, and Magnetometers.

    Science.gov (United States)

    Miklich, Andrew Hostetler

    The design and performance of high-T_ {rm c} dc superconducting quantum interference devices (SQUIDs), the junctions that comprise them, and magnetometers made from them are described, with special attention paid to sources of 1/f noise. Biepitaxial junctions are found to have large levels of critical current fluctuations which make them unsuitable for low-noise SQUIDs. This noise suggests a poorly connected interface at the grain boundary junction. SQUIDs from bicrystal junctions, in contrast, have levels of critical current noise that are controllable using bias current reversal techniques which leave the noise white down to frequencies of a few Hz. A SQUID with an energy resolution of 1.5times 10^{-30} J Hz^ {-1} at 1 Hz is reported. Magnetometers in which a (9 mm)^2 pickup loop is directly coupled to a SQUID body have achieved field resolutions of 93 fT Hz^{-1/2} down to frequencies below 1 Hz, improving to 39 fT Hz^{-1/2} at 1 Hz with the addition of a 50 mm-diameter single-turn flux transformer. Although the performance of these devices is sufficient for single -channel biomagnetometry or geophysical studies, their relatively poor coupling to the pickup loop makes it difficult to satisfy the competing goals of high field resolution and small detector size necessary for multichannel biomagnetic imaging. Improved coupling is demonstrated by the use of multiturn-input-coil flux transformers, and a resolution of 35 fT Hz^{-1/2} in the white noise region is reported with a (10 mm) ^2 pickup loop. However, additional 1/f noise from the processed multilayer structures in the transformer limits the resolution at 1 Hz to 114 fT Hz^ {-1/2}. High-T_{ rm c} SQUIDs are shown to exhibit additional 1/f noise when they are cooled in a nonzero static magnetic field because of the additional flux vortices trapped in the film, with the noise power at 1 Hz typically increasing by a factor of 10-20 in a field of 0.05 mT (0.5 G). Finally, a SQUID-based voltmeter with a resolution

  6. Final environmental statement for decommissioning Humboldt Bay Power Plant, Unit No. 3 (Docket No. 50-133)

    International Nuclear Information System (INIS)

    1987-04-01

    The Final Environmental Statement contains the assessment of the environmental impact associated with decommissioning the Humboldt Bay Power Plant Unit 3 pursuant to the National Environmental Policy Act of 1969 (NEPA) and Title 10 of the Code of Federal Regulations, Part 51, as amended, of the Nuclear Regulatory Commission regulations. The proposed decommissioning would involve safe storage of the facility for about 30 years, after which the residual radioactivity would be removed so that the facility would be at levels of radioactivity acceptable for release of the facility to unrestricted access

  7. Tod in den Anden. Ein Brief Francis Halls an Humboldt 1831 und seine historischen und politischen Hintergründe

    Directory of Open Access Journals (Sweden)

    Thomas Schmuck

    2013-12-01

    Full Text Available Zusammenfassung Der Forschungsreisende Francis Hall kam als Soldat nach Südamerika und betätigte sich hier auch als Pflanzensammler, Reiseschriftsteller und Bergsteiger. Er war Freund und Briefpartner Jeremy Benthams und versuchte gemeinsam mit Jean-Baptiste Boussingault den Chimborazo zu besteigen. Der liberale Journalist wurde 1833 in bürgerkriegsähnlichen Unruhen in Ecuador ermordet. Der einzige Brief Halls an Humboldt, in dem er diesen für die Naturerschließung des Landes zu gewinnen versucht, eine Sammlung andiner Pflanzen übersendet und seine Einschätzung zur politischen Lage und Zukunft Südamerikas kundtut, wird hier veröffentlicht und kommentiert. Abstract The British explorer Francis Hall was active in South-America as a soldier, a collector of plants, a writer of travelogues and a mountaineer. Together with Jean-Baptiste Boussingault he failed in ascending the Chimborazo. Friend and correspondent of Jeremy Bentham and also liberal journalist, Hall was killed during riots in Ecuador in 1833. In one single letter addressed to Humboldt, which is presented here, Hall tries to awaken interest for Ecuador, develops his views on the political future of South America and sends a collection of plants from the Andes. Resumen El explorador británico Francis Hall llegó a América del Sur como soldado y allí también se dedicó a la colección de plantas, a escribir sobre viajes y a hacer alpinismo. Intentó subir al Chimborazo con Jean-Baptiste Boussingault. El periodista liberal, amigo de Jeremy Bentham con el que también mantenía correspondencia, fue asesinado en los disturbios de 1833 en Ecuador. En la única carta de Hall a Humboldt, que está publicada y comentada aquí, Hall intenta despertar el interés de Humboldt por la naturaleza del país enviando una colección de plantas andinas y dando su opinión sobre la situación política y el futuro de América del Sur. (Traducción: Christine Lebas

  8. Trasmigrazione di piante trasferimenti di concetti: la lettura scientifica ed estetica del paesaggio sud americano in Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Alexander Di Bartolo

    2013-11-01

    Full Text Available The institution of plant geography as a science in Alexander von Humboldt implies for the first time the emergence of concept of migration concerning plants and animals. But plant geography and the study on vegetation in Humboldt’s books aims to conjugate various natural sciences in order to reach an understanding of the geographical distribution of vegetation. A new approach in South American analysis, connected with an aestethic lecture of Tropical lands of New Word, redefines the idea of “New” thanks to use of analogic concepts based on science and European aestethic lexicon.

  9. Overview of mine drainage geochemistry at historical mines, Humboldt River basin and adjacent mining areas, Nevada. Chapter E.

    Science.gov (United States)

    Nash, J. Thomas; Stillings, Lisa L.

    2004-01-01

    Reconnaissance hydrogeochemical studies of the Humboldt River basin and adjacent areas of northern Nevada have identified local sources of acidic waters generated by historical mine workings and mine waste. The mine-related acidic waters are rare and generally flow less than a kilometer before being neutralized by natural processes. Where waters have a pH of less than about 3, particularly in the presence of sulfide minerals, the waters take on high to extremely high concentrations of many potentially toxic metals. The processes that create these acidic, metal-rich waters in Nevada are the same as for other parts of the world, but the scale of transport and the fate of metals are much more localized because of the ubiquitous presence of caliche soils. Acid mine drainage is rare in historical mining districts of northern Nevada, and the volume of drainage rarely exceeds about 20 gpm. My findings are in close agreement with those of Price and others (1995) who estimated that less than 0.05 percent of inactive and abandoned mines in Nevada are likely to be a concern for acid mine drainage. Most historical mining districts have no draining mines. Only in two districts (Hilltop and National) does water affected by mining flow into streams of significant size and length (more than 8 km). Water quality in even the worst cases is naturally attenuated to meet water-quality standards within about 1 km of the source. Only a few historical mines release acidic water with elevated metal concentrations to small streams that reach the Humboldt River, and these contaminants and are not detectable in the Humboldt. These reconnaissance studies offer encouraging evidence that abandoned mines in Nevada create only minimal and local water-quality problems. Natural attenuation processes are sufficient to compensate for these relatively small sources of contamination. These results may provide useful analogs for future mining in the Humboldt River basin, but attention must be given to

  10. El Proyecto Humboldt: Una biblioteca digital para las expediciones científicas a las Islas Canarias*

    Directory of Open Access Journals (Sweden)

    Markus Schnoepf

    2005-04-01

    Full Text Available Article in Spanish, Abstracts in English, Spanish and German.The Proyecto Humboldt offers since 2002 a growing digital library for the investigation of the european scientific voyages to the Canary Islands between 1700 and 1900. The library is led by the Open Access spirit. Some results of the research work of the last years will be presented in this text. General comments on digital libraries and coming developments will be discussed in another part. Finally the special relationship of the humanities and computer-aided work will be looked at.

  11. Preparation and characterisation of irradiated crab chitosan and New Zealand Arrow squid pen chitosan

    International Nuclear Information System (INIS)

    Shavandi, Amin; Bekhit, Adnan A.; Bekhit, Alaa El-Din A.; Sun, Zhifa; Ali, M. Azam

    2015-01-01

    The properties of chitosan from Arrow squid (Nototodarus sloanii) pen (CHS) and commercial crab shell (CHC) were investigated using FTIR, DSC, SEM and XRD before and after irradiation at the dose of 28 kGy in the presence or absence of 5% water. Also, the viscosity, deacetylation degree, water and oil holding capacities, colour and antimicrobial activities of the chitosan samples were determined. Irradiation decreased (P < 0.05) the viscosity of CHC from 0.21 to 0.03 Pa s and of CHS from 1.71 to 0.23 Pa s. The inclusion of water had no effect on the viscosity of irradiated chitosan. Irradiation did not affect the degree of deacetylation of CHC, but increased the deacetylation degree of CHS from 72.78 to 82.29% in samples with 5% water. Water and oil holding capacities of CHS (1197.30% and 873.3%, respectively) were higher (P < 0.05) than those found in CHC (340.70% and 264.40%, respectively). The water and oil holding capacities were decreased for both types of chitosan irradiation, but were not affected by the addition of water. Squid pen chitosan was whiter in colour (White Index = 90.06%) compared to CHC (White Index = 83.70%). Generally, the CHC samples (control and irradiated) exhibited better antibacterial activity compared to CHS, but the opposite was observed with antifungal activity. - Highlights: • Chitosan prepared from Arrow squid pens (Nototodarus sloanii). • Chitosan samples were gamma irradiated at 28 kGy. • Squid pen chitosan showed high fat and water uptake capacities compared to crab shell chitosan. • Gamma irradiation enhanced the DDA of squid pen chitosan but not crab shell chitosan.

  12. Carbonate-cemented hardgrounds: a subtle indicator for seep activity offshore Humboldt Bay

    Science.gov (United States)

    Shapiro, R. S.; Bazard, D.

    2007-12-01

    Active hydrocarbon seeps are common in the accretionary prism of the Cascadia subduction zone. In Humboldt County, California, the prism is exposed at the surface as a series of fault-propagated anticlines trending NW-SE. Offshore of the town of Samoa, a northwest-plunging anticline is breached at approximately 40 meters water depth, allowing hydrocarbons to seep out to the seafloor (40.8° N, 124.25° W). The assumed microbial activity at the seep leads to the production of interstitial carbonate cements forming hardgrounds. Cementation is pervasive and blocks eroded from the seep area of the seabed are transported onshore during storm events. Blocks collected from the beach range from 3--40 centimeters across. The sediments of the blocks are palimpsest transgressive deposits composed mostly of immature fine sand, but ranging from very fine to rounded gravels 4 cm diameter. Cementation is not dependent on grain size as all of the sediment sizes are cemented. In rare void spaces, a concentric banding of cements is obvious. The interstitial cements preserve original sedimentary structures including graded beds and high-angle cross-beds. Centimeter-scale subspherical concretions occur on the undersides of some blocks. There is no disruption of bedding in contrast to other seeps where the expulsion of gas can create pockmarks, brecciation, and other disturbances. Unlike the better studied seeps farther south in the Eel River basin, the Samoa seeps do not seem to host a rich chemosynthetic fauna. Whole and (mostly) fragmented shells preserved by the cemented sands represent a typical benthic inner shelf community including Dendraster, Macoma, and Olivella. Burrows preserved in the sands are largely horizontal and 1--2 mm diameter. Seep carbonate-cemented hardgrounds are less well studied then the more obvious meter-scale 'chemoherm' deposits. However, they may be more prevalent in the rock record and provide a new proxy for locating ancient seeps and hydrocarbon

  13. Contrasting biogeochemical responses of ENSO induced upwelling variability in the Humboldt Current System

    Science.gov (United States)

    Franco, Ana C.; Gruber, Nicolas; Münnich, Matthias

    2017-04-01

    The Humboldt Current System (HCS) is one of the most productive ecosystems in the world. This high productivity is supported by a large input of nutrients from the subsurface layers to the surface due to year-round upwelling. However, upwelling also supplies waters with low pH and low aragonite saturation state potentially affecting many organisms, especially those that calcify. The influence, extent and source of upwelled water vary substantially on interannual timescales in association with the El Niño/Southern Oscillation (ENSO) phenomenon, generating natural contrasting responses on the biogeochemistry of this system. Here we analyze these responses using an eddy resolving, basin-scale ocean model that covers the whole Pacific Ocean with high resolution (4 km) on the west coast of South America. We performed a simulation of the last 30 years (hindcast simulation) that allows us to investigate the influence of at least eight El Niño episodes and eight La Niña episodes on productivity variations and changes in oxygen concentration and aragonite saturation state. An absolute change in surface omega aragonite of almost 2 units, as well as an absolute change of the aragonite saturation depth of 200 m result from the change of an El Niño phase to a La Niña phase. This variability is on the same order of magnitude as the projected change in the aragonite saturation state in a centennial timescale. During La Niña events, a lower aragonite saturation state values and reduced oxygen concentration in the surface layer are a direct consequence of enhanced upwelling and increased net primary productivity. The opposite is true during El Niño events, where high values of omega aragonite occur in concordance with extraordinarily low net primary productivity values.

  14. Humboldt's spa: microbial diversity is controlled by temperature in geothermal environments.

    Science.gov (United States)

    Sharp, Christine E; Brady, Allyson L; Sharp, Glen H; Grasby, Stephen E; Stott, Matthew B; Dunfield, Peter F

    2014-06-01

    Over 200 years ago Alexander von Humboldt (1808) observed that plant and animal diversity peaks at tropical latitudes and decreases toward the poles, a trend he attributed to more favorable temperatures in the tropics. Studies to date suggest that this temperature-diversity gradient is weak or nonexistent for Bacteria and Archaea. To test the impacts of temperature as well as pH on bacterial and archaeal diversity, we performed pyrotag sequencing of 16S rRNA genes retrieved from 165 soil, sediment and biomat samples of 36 geothermal areas in Canada and New Zealand, covering a temperature range of 7.5-99 °C and a pH range of 1.8-9.0. This represents the widest ranges of temperature and pH yet examined in a single microbial diversity study. Species richness and diversity indices were strongly correlated to temperature, with R(2) values up to 0.62 for neutral-alkaline springs. The distributions were unimodal, with peak diversity at 24 °C and decreasing diversity at higher and lower temperature extremes. There was also a significant pH effect on diversity; however, in contrast to previous studies of soil microbial diversity, pH explained less of the variability (13-20%) than temperature in the geothermal samples. No correlation was observed between diversity values and latitude from the equator, and we therefore infer a direct temperature effect in our data set. These results demonstrate that temperature exerts a strong control on microbial diversity when considered over most of the temperature range within which life is possible.

  15. Spatial and temporal variability of planktonic archaeal abundance in the Humboldt Current System off Chile

    Science.gov (United States)

    Quiñones, Renato A.; Levipan, Héctor A.; Urrutia, Homero

    2009-07-01

    The latest advances in the field of microbial ecology have shown that planktonic Archaea are one of the most abundant unicellular microorganisms of the oceans. However, no information is available on the contribution this group makes to the prokaryote assemblages that inhabit the eastern South Pacific Ocean. Here, we describe the relative abundance and vertical distribution of planktonic Archaea off northern and central-southern Chile. Data come from several cruises and a 45-month time series at a station located on the shelf off central-southern Chile. Both the taxonomic composition of the prokaryote community and its relative abundance were determined using quantitative dot blot 16S-rRNA hybridizations. Total Archaea in central-southern Chile made up 6-87% of the prokaryote rRNA in the water column and did not present evidence of any seasonal pattern. Crenarchaea were the most abundant archaeal group at this site and were significantly associated with the ammonium concentration ( r2=0.16, p=0.0003, n=80). Archaeal abundance in the time series was usually greater in the deeper layer (>50 m), with contributions reaching up to ˜90% of the prokaryote rRNA on certain occasions, and decreasing towards the surface. Important increments in the relative abundance of total Archaea were observed on given dates at the surface of the time-series station off central-southern Chile. Off northern Chile, total Archaea normally contributed from ˜10% to 50% of the prokaryote rRNA found between 10 and 1000 m, and were generally important in the mesopelagic realm. Our results indicate that Archaea constitute an important fraction of the prokaryote assemblage in the water column of the Humboldt Current System, especially in the oxygen minimum zone.

  16. Bacteriohopanepolyols along redox gradients in the Humboldt Current System off northern Chile.

    Science.gov (United States)

    Matys, E D; Sepúlveda, J; Pantoja, S; Lange, C B; Caniupán, M; Lamy, F; Summons, R E

    2017-11-01

    Marine oxygen minimum zones (OMZs) are characterized by the presence of subsurface suboxic or anoxic waters where diverse microbial processes are responsible for the removal of fixed nitrogen. OMZs have expanded over past decades and are expected to continue expanding in response to the changing climate. The implications for marine biogeochemistry, particularly nitrogen cycling, are uncertain. Cell membrane lipids (biomarkers), such as bacterial bacteriohopanepolyols (BHPs) and their degradation products (hopanoids), have distinctive structural attributes that convey information about their biological sources. Since the discovery of fossil hopanoids in ancient sediments, the study of BHPs has been of great biogeochemical interest due to their potential to serve as proxies for bacteria in the geological record. A stereoisomer of bacteriohopanetetrol (BHT), BHT II, has been previously identified in OMZ waters and has as been unequivocally identified in culture enrichments of anammox bacteria, a key group contributing to nitrogen loss in marine OMZs. We tested BHT II as a proxy for suboxia/anoxia and anammox bacteria in suspended organic matter across OMZ waters of the Humboldt Current System off northern Chile, as well as in surface and deeply buried sediments (125-150 ky). The BHT II ratio (BHT II/total BHT) increases as oxygen content decreases through the water column, consistent with previous results from Perú, the Cariaco Basin and the Arabian Sea, and in line with microbiological evidence indicating intense anammox activity in the Chilean OMZ. Notably, BHT II is transported from the water column to surface sediments, and preserved in deeply buried sediments, where the BHT II ratio correlates with changes in δ 15 N sediment values during glacial-interglacial transitions. This study suggests that BHT II offers a proxy for past changes in the relative importance of anammox, and fluctuations in nitrogen cycling in response to ocean redox changes through the

  17. A máquina da cultura: pedagogia e política entre Wilhelm von Humboldt e Nietzsche = The machine of the culture: pedagogy and politics between Wilhelm von Humboldt and Nietzsche

    Directory of Open Access Journals (Sweden)

    Britto, Fabiano de Lemos

    2011-01-01

    Full Text Available A relação entre as demandas da cultura e a interferência política do Estado na esfera da educação foi um dos temas mais importantes do debate intelectual na Alemanha desde o final do século XVIII até a unificação de 1871. A curva descrita por esse período, que tem Wilhelm von Humboldt e Nietzsche como seus dois extremos, constitui, em última análise, a própria trajetória do liberalismo no sistema de ensino alemão do século XIX. Ao reconstruirmos os elementos conceituais envolvidos nesse debate podemos não apenas resgatar as questões que permitiram ao modelo germânico alcançar o sucesso obtido na Europa de então como modelo pedagógico, mas, ao mesmo tempo, compreender como as filosofias de Humboldt e Nietzsche se caracterizaram, em certo momento, como um esforço de participar desta discussão

  18. Two Exceptional Witnesses of Latin American Independence: The Prussian Explorer Alexander Von Humboldt and The Virginian Politician Thomas Jefferson

    Directory of Open Access Journals (Sweden)

    Sandra Rebok

    2014-01-01

    Full Text Available Este artículo analiza las respectivas posturas de Alexander von Humboldt y Thomas Jefferson en relación con la independencia de los territorios hispanoamericanos y el modo en que estas se hallaban condicionadas por sus propias experiencias: Humboldt, como observador de la situación americana justo antes del comienzo de los movimientos independentistas; y Jefferson, como actor importante en la independencia de los EE.UU. y la posterior creación de una nueva sociedad. Asimismo, no se pueden estudiar sus respectivas posiciones hacia los movimientos independentistas en la América española, desvinculadas de sus conclusiones respecto a la Revolución francesa y sus consecuencias. El trabajo muestra de qué manera los dos personajes comentaron estos sucesos en la correspondencia que mantuvieron entre sí. Finalmente, también se evalúan, a través de estos famosos representantes del llamado Nuevo Mundo y el Viejo Mundo, las diferencias y similitudes en la manera de reaccionar ante estos eventos políticos y sociales desde el punto de vista europeo, en comparación con la mirada desde Norteamérica.

  19. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 1: formative years, naturphilosophie, and galvanism.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    During the 1790s, Alexander von Humboldt (1769-1859), who showed an early interest in many facets of natural philosophy and natural history, delved into the controversial subject of galvanism and animal electricity, hoping to shed light on the basic nature of the nerve force. He was motivated by his broad worldview, the experiments of Luigi Galvani, who favored animal electricity in more than a few specialized fishes, and the thinking of Alessandro Volta, who accepted specialized fish electricity but was not willing to generalize to other animals, thinking Galvani's frog experiments flawed by his use of metals. Differing from many German Naturphilosophen, who shunned "violent" experiments, the newest instruments, and detailed measurement, Humboldt conducted thousands of galvanic experiments on animals and animal parts, as well as many on his own body, some of which caused him great pain. He interpreted his results as supporting some but not all of the claims made by both Galvani and Volta. Notably, because of certain negative findings and phenomenological differences, he remained skeptical about the intrinsic animal force being qualitatively identical to true electricity. Hence, he referred to a "galvanic force," not animal electricity, in his letters and publications, a theoretical position he would abandon with Volta's help early in the new century.

  20. Behaviour of wintering Tundra Swans Cygnus columbianus columbianus at the Eel River delta and Humboldt Bay, California, USA

    Science.gov (United States)

    Black, Jeffrey M.; Gress, Carol; Byers, Jacob W.; Jennings, Emily; Ely, Craig R.

    2010-01-01

    Tundra Swan Cygnus columbianus columbinanus phenology and behaviour at the Eel River delta and southern Humboldt Bay in northern California, USA, is described. Counts made each January from 1963 onwards peaked at 1,502 swans in 1988. Monthly counts recorded during the 2006/07 and 2008/09 winters peaked in February, at 1,033 and 772 swans respectively. Swans roosted on ephemeral ponds at the Humboldt Bay National Wildlife Refuge, on ephemeral ponds within grassland pastures in the vicinity of the Refuge, and perhaps also used the Eel River as a roost. Flights between Refuge roosts and the pastures and ponds occurred in the two hours after sunrise and before dark. In winters 2008/09 and 2009/10, the percentage of cygnets in the flocks was 10.6% and 21.4% respectively, and increased to =31% cygnets each year after most swans had departed from the area in March. Average brood size in 2009/10 was 2.1 cygnets. Daily activities consisted of foraging (44.9% of activities recorded), comfort behaviour (22.1%), locomotion (16.2%) and vigilance (15.5%). Eight neck-collared swans identified in the wintering flock were marked at four locations in different parts of Alaska, up to 1,300 km apart.

  1. Rapid method for controlling the correct labeling of products containing common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas) by fast real-time PCR.

    Science.gov (United States)

    Espiñeira, Montserrat; Vieites, Juan M

    2012-12-15

    The TaqMan real-time PCR has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of species. This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas). This technique is notable for the combination of simplicity, speed, sensitivity and specificity in an homogeneous assay. The method can be applied to all kinds of products; fresh, frozen and processed, including those undergoing intensive processes of transformation. This methodology was validated to check how the degree of food processing affects the method and the detection of each species. Moreover, it was applied to 34 commercial samples to evaluate the labeling of products made from them. The methodology herein developed is useful to check the fulfillment of labeling regulations for seafood products and to verify traceability in commercial trade and for fisheries control. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Flux-coherent series SQUID array magnetometers operating above 77 K with superior white flux noise than single-SQUIDs at 4.2 K

    International Nuclear Information System (INIS)

    Chesca, Boris; John, Daniel; Mellor, Christopher J.

    2015-01-01

    A very promising direction to improve the sensitivity of magnetometers based on superconducting quantum interference devices (SQUIDs) is to build a series-array of N non-interacting SQUIDs operating flux-coherently, because in this case their voltage modulation depth, ΔV, linearly scales with N whereas the white flux noise S Φ 1/2 decreases as 1/N 1/2 . Here, we report the realization of both these improvements in an advanced layout of very large SQUID arrays made of YBa 2 Cu 3 O 7 . Specially designed with large area narrow flux focusers for increased field sensitivity and improved flux-coherency, our arrays have extremely low values for S Φ 1/2 between (0.25 and 0.44) μΦ 0 /Hz 1/2 for temperatures in the range (77–83) K. In this respect, they outperform niobium/aluminium trilayer technology-based single-SQUIDs operating at 4.2 K. Moreover, with values for ΔV and transimpedance in the range of (10–17) mV and (0.3–2.5) kΩ, respectively, a direct connection to a low-noise room temperature amplifier is allowed, while matching for such readout is simplified and the available bandwidth is greatly increased. These landmark performances suggest such series SQUID arrays are ideal candidates to replace single-SQUIDs operating at 4.2 K in many applications

  3. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1990-91

    Science.gov (United States)

    Seiler, R.L.; Ekechukwu, G.A.; Hallock, R.J.

    1993-01-01

    A reconnaissance investigation was begun in 1990 to determine whether the quality of irrigation drainage in and near the Humboldt Wildlife Management Area, Nevada, has caused or has the potential to cause harmful effects on human health, fish, and wildlife or to impair beneficial uses of water. Samples of surface and ground water, bottom sediment, and biota collected from sites upstream and downstream from the Lovelock agricultural area were analyzed for potentially toxic trace elements. Also analyzed were radioactive substances, major dissolved constitu- ents, and nutrients in water, as well as pesticide residues in bottom sediment and biota. In samples from areas affected by irrigation drainage, the following constituents equaled or exceeded baseline concentrations or recommended standards for protection of aquatic life or propagation of wildlife--in water: arsenic, boron, dissolved solids, mercury, molybdenum, selenium, sodium, and un-ionized ammonia; in bottom sediment; arsenic and uranium; and in biota; arsenic, boron, and selenium. Selenium appears to be biomagnified in the Humboldt Sink wetlands. Biological effects observed during the reconnaissance included reduced insect diversity in sites receiving irrigation drainage and acute toxicity of drain water and sediment to test organisms. The current drought and upstream consumption of water for irrigation have reduced water deliveries to the wetlands and caused habitat degradation at Humboldt Wildlife Management Area. During this investigation. Humboldt and Toulon Lakes evaporated to dryness because of the reduced water deliveries.

  4. First report of the white pine blister rust fungus, Cronartium ribicola, infecting Pinus flexilis on Pine Mountain, Humboldt National Forest, Elko County, northeastern Nevada, U.S.A.

    Science.gov (United States)

    Detlev R. Vogler; Patricia E. Maloney; Tom Burt; Jacob W. Snelling

    2017-01-01

    In 2013, while surveying for five-needle white pine cone crops in northeastern Nevada, we observed white pine blister rust, caused by the rust pathogen Cronartium ribicola Fisch., infecting branches and stems of limber pines (Pinus flexilis James) on Pine Mountain (41.76975°N, 115.61622°W), Humboldt National Forest,...

  5. Mismatch Between Interseismic Ground Deformation and Paleoseismic/Paleogeodetic Observations, Humboldt Bay, Northern California, Cascadia Subduction Zone

    Science.gov (United States)

    Patton, J. R.; Williams, T. B.; Leroy, T. H.; Anderson, J. K.; Weldon, R. J.; Gilkerson, W.

    2011-12-01

    Observations made by Plafker in Chile (1960) and Alaska (1964) show that vertical deformation during earthquakes is generally opposite in sense of motion compared to interseismic deformation. This elastic rebound theory drives estimates of potential coseismic deformation on the Cascadia subduction zone (CSZ). Similar to other coastal marshes along the CSZ, paleoseismic investigations around Humboldt Bay reveal evidence of coseismic subsidence for the past 4 ka. Tide gage data obtained from NOAA tide gages, as well as 'campaign' style tide gages, are used to infer interseismic ground deformation. Tide gage data from Crescent City and Humboldt Bay are compared to each other and also compared to estimates of eustatic sea-level rise to estimate rates of land-level change. Earthscope and USGS GPS permanent site data are also used to evaluate vertical interseismic deformation in this region. These rates of land-level change are then compared to paleoseismic proxies for vertical land-level change. Cores collected for master's theses research at Humboldt State University were used to compile an earthquake history for the Humboldt Bay region. Some cores in Mad River and Hookton sloughs were used to evaluate magnitudes of coseismic subsidence by comparing diatom and foraminiferid assemblages associated with lithologic contacts (paleogeodesy). Minimum estimates of paleosubsidence for earthquakes range from 0.3 to 2.6 meters. Subtracting eustatic sea-level rise (~2.3 mm/yr, 1977-2010) from Crescent City (CC) and North Spit (NS) relative sea-level rates reveals that CC is uplifting at ~3mm/yr and NS is subsiding at ~2.5 mm/yr. GPS vertical deformation reveals similar rates of ~3 mm/yr of uplift and ~2 mm/yr of subsidence in these two locations. GPS based subsidence rates show a gradient of subsidence between Trinidad (in the north) to Cape Mendocino (in the south). The spatial region of ongoing subsidence reveals the depth of locking of the CSZ fault (differently from previous

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

    Science.gov (United States)

    Anderson, E J; DeMont, M E

    2000-09-01

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

  7. Le Cosmos d'Alexandre von Humboldt et La Tentation de saint Antoine de Gustave Flaubert : deux œuvres de toute une vie

    Directory of Open Access Journals (Sweden)

    Mary Orr

    2010-12-01

    Full Text Available Dans le septième et dernier tableau de La Tentation de saint Antoine de 1874, la fin célèbre est mise en contexte par une description longue et détaillée qui n’a jamais attiré l’attention critique qu’elle mérite. Cet article analyse l’importance de ce panorama du monde naturel sous la forme d’une exploration intertextuelle des passages du Cosmos d’Alexandre de Humboldt. Que Flaubert signale ses lectures de l’œuvre de Humboldt dans sa Correspondance de 1860 suggère des liens très riches entre Le Cosmos – que Humboldt désigne comme « l’œuvre de ma vie » – et la Tentation de saint Antoine définitive que Flaubert retravaillait au même moment. Cette relecture de La Tentation à travers la perspective de Humboldt souligne la place importante du Cosmos parmi les découvertes et les textes scientifiques contemporains de Flaubert, et la manière dont ceux-ci informent la vision de la vie scientifique et religieuse de son protagoniste, Antoine.In the seventh and final tableau of the Tentation de Saint Antoine of 1874, the famous finale is set in the context of a long, detailed description which has not attracted the critical attention it deserves. This article focuses on the importance of this panorama of the natural world as an intertextual exploration of passages from Kosmos by Alexander von Humboldt. The fact that Flaubert’s Correspondance of 1860 mentions his reading of Humboldt’s works suggests rich lines of investigation between Kosmos – which Humboldt calls the « work of all of life » and the final Tentation de Saint Antoine,which Flaubert was reworking at the same moment. This re-reading of the Tentation through the optic of Humboldt underscores the pivotal position of Kosmos amid the scientific discoveries and texts contemporary to Flaubert, and how these inform the vision of life of his protagonist, Antoine, as scientific and religious.

  8. Influence of gamma irradiation and low temperature storage on the quality and shelf life of squid (Doryteuthis sibogae

    Directory of Open Access Journals (Sweden)

    Manjanaik, B.

    2017-08-01

    Full Text Available Irradiation is considered as an efficient method for the reduction of microorganisms in food. It has been used to improve the safety and shelf life of food products. The present investigation is aimed at studying the influence of gamma irradiation (3 and 5 kGy and subsequent storage at refrigeration temperature (4oC on the chemical, microbial qualities and extended shelf life of squid (Doryteuthis sibogae. The total volatile base nitrogen (TVB-N and trimethyl amine nitrogen values (TMA-N of the irradiated squid samples significantly decreased in comparison with the control (non-irradiated stored at 4oC. The thiobarbituric acid values for the irradiated squid was significantly lower than of the non-irradiated samples stored at 4oC (p<0.05. The pH value of the squid was affected significantly by both, irradiation dose and storage temperature (p<0.05. The total microbial load for the non-irradiated squid samples was higher than those of irradiated samples at 4oC temperature. The results revealed that the combination of irradiation and refrigerated storage resulted in a significant reduction of microbial growth and stabilized the biochemical characteristics of squid.

  9. Studies on the effect of low dose gamma irradiation on the chemical, microbial quality and shelf life of squid

    International Nuclear Information System (INIS)

    Bojayanaik, Manjanaik; Naroth, Kavya; Shetty, Veena; Hiriyur, Somashekarappa

    2014-01-01

    The present investigation was carried out to study the combined effect of low dose gamma irradiation (1, 3 and 5 kGy) and storage at refrigeration (+4℃) and frozen (-18℃) temperatures, on the shelf life extension of fresh squid. The study was based on microbiological and physico-chemical changes occurring in the squid samples. The biochemical parameters such as total volatile base nitrogen and trimethyl amine nitrogen values for irradiated squid samples were significantly lower than non-irradiated samples at both storage temperatures and the rate of decrease was more pronounced in samples irradiated at the higher dose of 3 and 5 kGy (p<0.05). pH values of squid samples were affected by both irradiation dose and storage temperature (p<0.05). Total microbial load for non- irradiated (control) squid samples were higher than the respective irradiated samples at both storage temperatures. The results revealed that the combination of irradiation and low temperature storage resulted in a significant reduction of microbial growth and extend the shelf life of squid at refrigeration and frozen temperature to about 12 and 90 days respectively. (author)

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

    Science.gov (United States)

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

    2017-07-01

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

  11. Ultra-sensitive sensors for weak electromagnetic fields using high-Tc SQUIDS for biomagnetism, NDE, and corrosion currents

    International Nuclear Information System (INIS)

    Kraus, R.H. Jr.; Flynn, E.R.; Espy, M.; Jia, Q.X.; Wu, X.D.; Reagor, D.

    1998-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The research has directly contributed to a new DOE supported project, three patents (one granted and two submitted), and several potential opportunities for new program funding at the Laboratory. The authors report significant developments extending from basic understanding of and fabrication techniques for high critical-temperature (high-T c ) SQUID devices to the development of high-level applications such as the SQUID Microscope. The development of ramp edge geometry and silver-doped YBa 2 Cu 3 O 7-x (YBCO) electrodes has tremendously improved the performance of high-T c SQUIDS. Recent experiments have proven and quantified the LANL-patented superconducting imaging plane gradiometry concept. A SQUID microscope, developed largely under this project, has recently acquired data that demonstrated exceptional sensitivity and resolution. New techniques for background noise suppression, needed to use the extraordinarily sensitive SQUID sensors in unshielded environments, have also been developed. Finally, initial investigations to use SQUIDs in a basic physics experiment to measure the electric dipole moment of the neutron were very successful

  12. Euphausia mucronata: A keystone herbivore and prey of the Humboldt Current System

    Science.gov (United States)

    Antezana, Tarsicio

    2010-04-01

    Euphausiids are important components of many ecosystems, especially in productive regions of temperate and high latitudes. The present paper makes the case that E. mucronata plays a keystone role in the food web of the Humboldt Current System (HCS) based on a synthesis of new and published data supporting its potential role as a primary grazer, as well as a principal prey for upper trophic level fish. E. mucronata is an endemic species, concentrated in the coastal upwelling belt of the HCS, with morpho-physiological adaptations to vertically migrate into the Oxygen Minimum Zone (OMZ). Within the 100-km coastal belt of the HCS it accounts for ca. 50% of the meso zooplankton wet weight in winter. In the mixed layer, it is a herbivore with high night ingestion rates (612.2 ng Chl eq ind -1 h -1 or 1013.9 μg C ind -1 d -1, in winter), and accounted for a 19.3% impact on primary production in winter, at an intermediate population abundance (3.8 ind m -3). At higher abundances (50 ind m -3) equivalent to swarms, impact on primary production could reach 254%. Additionally E. mucronata is a common prey of numerous upper trophic level predators. The diet of jack mackerel ( Trachurus murphyi) off central Chile (34-39°S) indicates a striking dependence on E. mucronata prey (average of 75% of stomach content in weight). The fishing season off central Chile extended from austral fall (March-April) and continued at least until the end of austral winter (September). The average daily ration of jack mackerel was 17.4 g, which is equivalent to 2.3% of fish body weight per day. The total E. mucronata consumed in 1991 by the landed population of fish (3.7 million tons yr -1) amounted to 23.2 million tons yr -1. The total estimated population of jack mackerel that year (17.6 million tons) would have consumed ca. 110.2 million tons of E. mucronata. Based on stomach contents, consumption of E. mucronata by other nektonic predators off Chile and off Peru is also outstanding. Four

  13. The Humboldt Current System: Ecosystem components and processes, fisheries, and sediment studies

    Science.gov (United States)

    Montecino, Vivian; Lange, Carina B.

    2009-12-01

    In the Humboldt Current System (HCS), biological and non-biological components, ecosystem processes, and fisheries are known to be affected by multi-decadal, inter-annual, annual, and intra-seasonal scales. The interplay between atmospheric variability, the poleward undercurrent, the shallow oxygen minimum zone (OMZ), and the fertilizing effect of coastal upwelling and overall high primary production rates drive bio-physical interactions, the carbon biomass, and fluxes of gases and particulate and dissolved matter through the water column. Coastal upwelling (permanent and seasonally modulated off Peru and northern Chile, and markedly seasonal between 30°S and 40°S) is the key process responsible for the high biological productivity in the HCS. At present, the western coast of South America produces more fish per unit area than any other region in the world ocean (i.e. ∼7.5 × 10 6 t of anchoveta were landed in 2007). Climate changes on different temporal scales lead to alterations in the distribution ranges of anchoveta and sardine populations and shifts in their dominance throughout the HCS. The factors affecting the coastal marine ecosystem that reverberate in the fisheries are crucial from a social perspective, since the economic consequences of mismanagement can be severe. Fish remains are often well-preserved in sediment settings under the hypoxic conditions of the OMZ off Peru and Chile, and reveal multi-decadal variability and centennial-scale changes in fish populations. Sediment studies from the Chilean continental margin encompassing the last 20,000 years of deposition reveal changes in sub-surface conditions in the HCS during deglaciation, interpreted to include: a major reorganization of the OMZ; a deglacial increase in denitrification decoupled from local marine productivity; and higher deglacial and Holocene paleoproductivities compared to the Last Glacial Maximum in central-south Chile (35-37°S) while this scheme is reversed for north

  14. Considerações sobre os conceitos de natureza, espaço e morfologia em Alexander von Humboldt e a gênese da geografia física moderna Considerations on the concepts of nature, space, and morphology in Alexander von Humboldt and on the genesis of modern physical geography

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Vitte

    2010-01-01

    Full Text Available Discute a formação dos conceitos de natureza, espaço e morfologia na obra de Alexander von Humboldt e seus impactos na formação da geografia física moderna. Influenciado pelas reflexões de Kant em Crítica do juízo e pelos trabalhos de Goethe e Schelling, Humboldt desenvolveu nova interpretação e representação para a natureza na superfície da Terra, em que o conceito de espacialidade é fundamental para a explicação dos fenômenos da natureza. A geografia física moderna estrutura-se a partir de complexo cruzamento de influências estéticas e instrumentais desenvolvidas por Humboldt, nas quais o princípio da conexão é importante para a invenção artística e científica do conceito de paisagem geográfica.The article discusses how Alexander von Humboldt developed the concepts of nature, space, and morphology in his works and impacted the shaping of modern physical geography. Influenced by Kant's ideas in Critique of judgment and also by the writings of Goethe and Schelling, Humboldt devised a new interpretation and representation of nature on Earth's surface, wherein the concept of space is essential to explaining natural phenomena. Modern physical geography is grounded in a complex interweaving of aesthetic and instrumental influences fashioned by Humboldt, with the principle of connection playing an important role in the artistic and scientific development of the notion of a geographic landscape.

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

    Science.gov (United States)

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

    1979-01-01

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

  16. Polarization sensitivity and retinal topography of the striped pyjama squid (Sepioloidea lineolata - Quoy/Gaimard 1832).

    Science.gov (United States)

    Talbot, Christopher M; Marshall, Justin

    2010-10-01

    Coleoid cephalopods (octopus, cuttlefish and squid) potentially possess polarization sensitivity (PS) based on photoreceptor structure, but this idea has rarely been tested behaviourally. Here, we use a polarized, striped optokinetic stimulus to demonstrate PS in the striped pyjama squid, Sepioloidea lineolata. This species displayed strong, consistent optokinetic nystagmic eye movements in response to a drum with stripes producing e-vectors set to 0 deg, 45 deg, 90 deg and 135 deg that would only be visible to an animal with PS. This is the first behavioural demonstration of a polarized optokinetic response in any species of cephalopod. This species, which typically sits beneath the substrate surface looking upwards for potential predators and prey, possesses a dorsally shifted horizontal pupil slit. Accordingly, it was found to possess a horizontal strip of high-density photoreceptors shifted ventrally in the retina, suggesting modifications such as a change in sensitivity or resolution to the dorsal visual field.

  17. High-Tc SQUID gradiometer system for magnetocardiography in an unshielded environment

    International Nuclear Information System (INIS)

    Liao, S H; Hsu, S C; Lin, C C; Horng, H E; Chen, J C; Chen, M J; Wu, C H; Yang, H C

    2003-01-01

    We set up an electronic gradiometer for magnetocardiography (MCG) in an unshielded environment. The electronically balanced gradiometer consists of high-temperature radio-frequency superconducting quantum interference device (rf SQUID) magnetometers. The rf SQUID magnetometers are arranged to form the electronic first-order, four-vector gradiometer, or second-order gradiometer. The output of the MCG signal was filtered by a band pass (1-30 Hz) and power line filters. We can reduce the noise to ∼1 pT Hz -1/2 at 1 Hz for second-order or four-vector gradiometers. Two-dimensional MCG imaging is demonstrated. The results are discussed with data measured in the moderate magnetically shielded environment

  18. Habitat and distribution of post-recruit life stages of the squid Loligo forbesii

    Science.gov (United States)

    Smith, Jennifer M.; Macleod, Colin D.; Valavanis, Vasilis; Hastie, Lee; Valinassab, Tooraj; Bailey, Nick; Santos, M. Begoña; Pierce, Graham J.

    2013-10-01

    This study models habitat preferences of the squid Loligo forbesii through its post-recruitment life cycle in waters around Scotland (UK). Trawl survey and market sample data from 1985 to 2004 are used to model seasonal habitats of immature, maturing and mature squid (maturity being inferred from size and season). Squid presence-absence and catch rate in areas of presence were analysed using generalised additive models, relating spatiotemporal patterns of distribution and abundance to ecogeographic variables. For all maturity classes, higher abundance in winter and spring (i.e., quarters 1 and 2) was associated with deeper water while higher abundance in summer and autumn (quarters 3 and 4) was associated with shallower water, consistent with seasonal onshore-offshore migrations but suggesting that most spawning may take place in deeper waters. The preferred SST range was generally 8-8.75 °C while preferred salinity values were below 35‰ in winter and summer and above 35‰ in spring and autumn. Squid were positively associated with gravel substrate and negatively associated with mud. Seasonal changes in habitat use were more clearly evident than changes related to inferred maturity, although the two effects cannot be fully separated due to the annual life cycle. Habitat selection for this species can be satisfactorily modelled on a seasonal basis; predictions based on such models could be useful for fishers to target the species more effectively, and could assist managers wishing to protect spawning grounds. The extent to which this approach may be useful for other cephalopods is discussed.

  19. Ultra-Low Field SQUID-NMR using LN2 Cooled Cu Polarizing Field coil

    Science.gov (United States)

    Demachi, K.; Kawagoe, S.; Ariyoshi, S.; Tanaka, S.

    2017-07-01

    We are developing an Ultra-Low Field (ULF) Magnetic Resonance Imaging (MRI) system using a High-Temperature Superconductor superconducting quantum interference device (HTS rf-SQUID) for food inspection. The advantages of the ULF-NMR (Nuclear Magnetic Resonance) / MRI as compared with a conventional high field MRI are that they are compact and of low cost. In this study, we developed a ULF SQUID-NMR system using a polarizing coil to measure fat of which relaxation time T1 is shorter. The handmade polarizing coil was cooled by liquid nitrogen to reduce the resistance and accordingly increase the allowable current. The measured decay time of the polarizing field was 40 ms. The measurement system consisted of the liquid nitrogen cooled polarizing coil, a SQUID, a Cu wound flux transformer, a measurement field coil for the field of 47 μT, and an AC pulse coil for a 90°pulse field. The NMR measurements were performed in a magnetically shielded room to reduce the environmental magnetic field. The size of the sample was ϕ35 mm × L80 mm. After applying a polarizing field and a 90°pulse, an NMR signal was detected by the SQUID through the flux transformer. As a result, the NMR spectra of fat samples were obtained at 2.0 kHz corresponding to the measurement field Bm of 47 μT. The T1 relaxation time of the mineral oil measured in Bm was 45 ms. These results suggested that the ULF-NMR/MRI system has potential for food inspection.

  20. Limits to the observation of coherent oscillations in a SQUID ring

    International Nuclear Information System (INIS)

    Diggins, J.

    1995-01-01

    Using the quantum mechanical, lumped component model of a SQUID ring we compute the onset of tunnelling and macroscopic superposition behaviour in the parameter space of the ring. In addition, we make a quantitative estimate of the stability required in the environmental flux to sustain a superposition state. Both these features are of crucial importance to the realisation of experiments aimed at revealing such behaviour. (orig.)

  1. Sneaker Male Squid Produce Long-lived Spermatozoa by Modulating Their Energy Metabolism

    OpenAIRE

    Hirohashi, Noritaka; Tamura-Nakano, Miwa; Nakaya, Fumio; Iida, Tomohiro; Iwata, Yoko

    2016-01-01

    Spermatozoa released by males should remain viable until fertilization. Hence, sperm longevity is governed by intrinsic and environmental factors in accordance with the male mating strategy. However, whether intraspecific variation of insemination modes can impact sperm longevity remains to be elucidated. In the squid Heterololigo bleekeri, male dimorphism (consort and sneaker) is linked to two discontinuous insemination modes that differ in place and time. Notably, only sneaker male spermato...

  2. SiGe Integrated Circuit Developments for SQUID/TES Readout

    Science.gov (United States)

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

    2018-03-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  4. K+/Na+-triggered bioluminescence in the oceanic squid Symplectoteuthis oualaniensis

    OpenAIRE

    Tsuji, Frederick I.; Leisman, Gary B.

    1981-01-01

    A distinctive type of luminescent system present in the large dorsal luminous organ of the oceanic squid Symplectoteuthis oualaniensis is described. The organ produces an intense blue flash of light followed by a rapid decay in light intensity. Luminescence originates from numerous oval granules present in the luminous organ. The essential light-emitting components are membrane bound. Intact granules or washed homogenates of the granules are triggered to emit light by monovalent cations such ...

  5. Halide peroxidase in tissues that interact with bacteria in the host squid Euprymna scolopes.

    Science.gov (United States)

    Small, A L; McFall-Ngai, M J

    1999-03-15

    An enzyme with similarities to myeloperoxidase, the antimicrobial halide peroxidase in mammalian neutrophils, occurs abundantly in the light organ tissue of Euprymna scolopes, a squid that maintains a beneficial association with the luminous bacterium Vibrio fischeri. Using three independent assays typically applied to the analysis of halide peroxidase enzymes, we directly compared the activity of the squid enzyme with that of human myeloperoxidase. One of these methods, the diethanolamine assay, confirmed that the squid peroxidase requires halide ions for its activity. The identification of a halide peroxidase in a cooperative bacterial association suggested that this type of enzyme can function not only to control pathogens, but also to modulate the interactions of host animals with their beneficial partners. To determine whether the squid peroxidase functions under both circumstances, we examined its distribution in a variety of host tissues, including those that typically interact with bacteria and those that do not. Tissues interacting with bacteria included those that have specific cooperative associations with bacteria (i.e., the light organ and accessory nidamental gland) and those that have transient nonspecific interactions with bacteria (i.e., the gills, which clear the cephalopod circulatory system of invading microorganisms). These bacteria-associated tissues were compared with the eye, digestive gland, white body, and ink-producing tissues, which do not typically interact directly with bacteria. Peroxidase enzyme assays, immunocytochemical localization, and DNA-RNA hybridizations showed that the halide-dependent peroxidase is consistently expressed in high concentration in tissues that interact bacteria. Elevated levels of the peroxidase were also found in the ink-producing tissues, which are known to have enzymatic pathways associated with antimicrobial activity. Taken together, these data suggest that the host uses a common biochemical response to

  6. Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes.

    OpenAIRE

    Boettcher, K J; Ruby, E G

    1990-01-01

    Bioluminescent marine bacteria of the species Vibrio fischeri are the specific light organ symbionts of the sepiolid squid Euprymna scolopes. Although they share morphological and physiological characteristics with other strains of V. fischeri, when cultured away from the light organ association the E. scolopes symbionts depress their maximal luminescence over 1,000-fold. The primary cause of this reduced luminescence is the underproduction by these bacteria of luciferase autoinducer, a molec...

  7. Phylogeographical patterns among Mediterranean sepiolid squids and their Vibrio symbionts: environment drives specificity among sympatric species.

    Science.gov (United States)

    Zamborsky, D J; Nishiguchi, M K

    2011-01-01

    Bobtail squid from the genera Sepiola and Rondeletiola (Cephalopoda: Sepiolidae) form mutualistic associations with luminous Gram-negative bacteria (Gammaproteobacteria: Vibrionaceae) from the genera Vibrio and Photobacterium. Symbiotic bacteria proliferate inside a bilobed light organ until they are actively expelled by the host into the surrounding environment on a diel basis. This event results in a dynamic symbiont population with the potential to establish the symbiosis with newly hatched sterile (axenic) juvenile sepiolids. In this study, we examined the genetic diversity found in populations of sympatric sepiolid squid species and their symbionts by the use of nested clade analysis with multiple gene analyses. Variation found in the distribution of different species of symbiotic bacteria suggests a strong influence of abiotic factors in the local environment, affecting bacterial distribution among sympatric populations of hosts. These abiotic factors include temperature differences incurred by a shallow thermocline, as well as a lack of strong coastal water movement accompanied by seasonal temperature changes in overlapping niches. Host populations are stable and do not appear to have a significant role in the formation of symbiont populations relative to their distribution across the Mediterranean Sea. Additionally, all squid species examined (Sepiola affinis, S. robusta, S. ligulata, S. intermedia, and Rondeletiola minor) are genetically distinct from one another regardless of location and demonstrate very little intraspecific variation within species. These findings suggest that physical boundaries and distance in relation to population size, and not host specificity, are important factors in limiting or defining gene flow within sympatric marine squids and their associated bacterial symbionts in the Mediterranean Sea.

  8. Electronics for a Next-Generation SQUID-Based Time-Domain Multiplexing System

    International Nuclear Information System (INIS)

    Reintsema, C. D.; Doriese, W. R.; Hilton, G. C.; Irwin, K. D.; Krinsky, J. W.; Adams, J. S.; Baker, R.; Bandler, S. R.; Kelly, R. L.; Kilbourne, C. A.; Porter, F. S.; Figueroa-Feliciano, E.; Wikus, P.

    2009-01-01

    A decade has elapsed since the design, development and realization of a SQUID-based time-division multiplexer at NIST. During this time the system has been used extensively for low-temperature-detector-array measurements. Concurrently, there have been substantial advancements both in detector array and commercial electronic component technology. The relevance and applicability of the technology has blossomed as well, often accompanied by more demanding measurement requirements. These factors have motivated a complete redesign of the NIST room-temperature read-out electronics. The redesign has leveraged advancements in component technology to achieve new capabilities better suited to the SQUID multiplexers and detector arrays being realized today. As examples of specific performance enhancements, the overall system bandwidth has been increased by a factor of four (a row switching rate of 6.24 MHz), the compactness has been increased by over a factor of two (a higher number of detector columns and rows per circuit board), and there are two high speed outputs per column (allowing fast switching of SQUID offsets in addition to digital feedback). The system architecture, design implementations, and performance advantages of the new system will be discussed. As an application example, the science chain flight electronics for the Micro-X High Resolution Microcalorimeter X-ray Imaging Rocket will be described as both a motivation for, and a direct implementation of the new system.

  9. SQUID Based Cryogenic Current Comparator for Measurements of the Dark Current of Superconducting Cavities

    CERN Document Server

    Vodel, W; Neubert, R; Nietzsche, S

    2005-01-01

    This contribution presents a LTS-SQUID based Cryogenic Current Comparator (CCC) for detecting dark currents, generated e.g. by superconducting cavities for the upcoming X-FEL project at DESY. To achieve the maximum possible energy the gradients of the superconducting RF cavities should be pushed close to the physical limit of 50 MV/m. The measurement of the undesired field emission of electrons (the so-called dark current) in correlation with the gradient will give a proper value to compare and classify the cavities. The main component of the CCC is a high performance LTS-DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted dark current. For this reason the input coil of the SQUID is connected across a special designed toroidal niobium pick-up coil (inner diameter: about 100 mm) for the passing electron beam. A noise limited current resolution of nearly 2 pA/√(Hz) with a measurement bandwidth of up to 70 kHz was achieved without the pick-up coil. Now, ...

  10. HTS-SQUID NDE Technique for Pipes based on Ultrasonic Guided Wave

    International Nuclear Information System (INIS)

    Hatsukade, Y; Masutani, N; Teranishi, S; Masamoto, K; Kanenaga, S; Adachi, S; Tanabe, K

    2017-01-01

    This article describes research on the novel high-temperature superconductor (HTS) superconducting quantum interference device (SQUID) non-destructive evaluation (NDE) technique for metallic pipes based on ultrasonic guided waves. We constructed HTS-SQUID NDE system for pipes based on ultrasonic guided waves, which were generated and received by means of the magnetostrictive effects. Using the system, we measured magnetic signals due to T (0, 1) mode ultrasonic guided waves that transmitted on aluminium pipe, and investigated influences of measurement parameters to the magnetic signals, such as direction of a HTS-SQUID gradiometer, lift-off distance, and intensity and frequency of input current fed to a magnetostrictive transmitter. With the gradiometer oriented parallel to the pipe axis, more than 10 times larger signals were measured compared with that oriented perpendicular to the pipe axis. Magnetic signals measured by the gradiometer were inverse proportional to the power of the list- off distance, and proportional to the intensity of the input current up to 1 A pp . Relation between the frequency of the input current and the measured signal was shown and discussed. (paper)

  11. Optimization of a digital SQUID magnetometer in terms of noise and distortion

    International Nuclear Information System (INIS)

    Haverkamp, I; Toepfer, H; Wetzstein, O; Kunert, J; Stolz, R; Meyer, H-G; Ortlepp, T

    2012-01-01

    The digital SQUID magnetometer takes advantage of flux quantization in a superconducting loop in order to measure magnetic fields. The core element of the digital SQUID is a Josephson comparator with a superconducting antenna loop attached to one of its junctions. Evaluation of the circuit from the system’s point of view requires an analysis in the frequency domain. In order to obtain a high-resolution fast Fourier transform, large datasets are necessary which are difficult to generate with transient simulation tools. In this work we derive a behavioural model for the digital SQUID in order to overcome restrictions imposed by transient simulation. By means of this model the influence of the comparator grey zone and the input loop inductance on the system performance was analysed. In order to assess the system, evaluation criteria based on the power spectral density were applied, which are commonly used for characterization of semiconductor analogue to digital converters. As a result of this study, design guidelines for an optimum antenna inductance depending on the comparator grey zone are derived, allowing us to achieve an optimum system performance in terms of noise and distortion. (paper)

  12. Spawning pattern of the neon flying squid Ommastrephes bartramii (Cephalopoda: Oegopsida around the Hawaiian Islands

    Directory of Open Access Journals (Sweden)

    Dharmamony Vijai

    2014-12-01

    Full Text Available The neon flying squid, Ommastrephes bartramii, is an oceanic squid species that is widely distributed in the North Pacific, with the winter-spring cohort spawning around the Hawaiian Islands. Here, we investigated the spawning characteristics of O. bartramii by analyzing various reproductive parameters of individuals (622 males, 108 females collected in this region. Female spawning status was determined from the somatic indices and histological characteristics of the ovaries. At all developmental stages, the ovaries of spawned females contained oocytes, and oviduct fullness was not correlated with body size. Thus, because the eggs mature asynchronously, with multiple filling and evacuation events, this species is considered an intermittent spawner. Mature males with developed accessory glands were also present within the distribution range of healthy spawned females, indicating that mating occurs between spawning events. Our data indicate that the first spawning event occurs at a mantle length of ~520-540 mm for Hawaiian O. bartramii. Subsequently, the squid forage and grow, and refill the oviducts, before the second spawning event occurs.

  13. Specific accumulation of polychlorinated biphenyls and organochlorine pesticides in Japanese common squid as a bioindicator

    International Nuclear Information System (INIS)

    Ueno, D.; Inoue, S.; Ikeda, K.; Tanaka, H.; Yamada, H.; Tanabe, S.

    2003-01-01

    Japanese common squid is a suitable bioindicator for monitoring organochlorines pollution in waters around Japan. - Organochlorines (OCs) representing Persistent Organic Pollutants (POPs) such as PCBs (polychlorinated biphenyls), DDTs (DDT and its metabolites), CHLs (chlordane compounds), HCHs (hexachlorocyclohexane isomers) and HCB (hexachlorobenzene) were determined in the liver of Japanese common squid (Todarodes pacificus) collected from the waters around Japan (Japan Sea and western North Pacific Ocean). Among OCs concentrations, PCBs (upto 5600 ng/g lipid wt.) were the highest, and those of other OCs were in the order of DDT> CHLs > HCHs > HCB. Studies on growth trend and seasonal variation of OCs in this species suggest a rapid reflection of the pollution levels in seawater where and when they were collected, regardless of body-length and time of collection. These results indicate that Japanese common squid is a suitable bioindicator for monitoring OCs pollution in waters around Japan. With regard to the geographical distribution of OCs in this species collected from waters around Japan, OCs concentrations in specimens from Japan Sea were higher than those from the Pacific Ocean. This result might reflect some existing of local pollution sources of OCs around Japan Sea, and slower water exchange between Japan Sea and open ocean

  14. SQUID magnetometry and magneto-optics of epitaxial EuS

    International Nuclear Information System (INIS)

    Rumpf, K.; Granitzer, P.; Krenn, H.; Kellner, W.; Pascher, H.; Kirchschlager, R.; Janecek, S.

    2004-01-01

    The complicated (H,T)-magnetic phase diagram of EuS is caused by the critical balance between nearest and next nearest neighbour exchange interaction (J NN = 0.119 K and J NNN =-0.1209 K) and leads to various spin arrangements NNSS..., NSN..., NNS, NNN... [NS denotes opposite ferromagnetic order in adjacent (111) planes]. Beside the subtle local exchange of 5d-t 2g electrons and localized holes with neighbouring Eu-4f spins, obviously also the strain status influences the occurrence of these different phases. We investigate the magnetic ordering phenomenon in a strained 2.5 μm EuS film on BaF 2 substrate by SQUID magnetometry and magneto-optics like spectral Faraday- and Kerr-effect measurements for temperatures from 2 K up to 200 K and for magnetic field up to 5 T. The magneto-optical probe monitors the local environment of the photoexcited electron-hole pair, called magnetic exciton, located within a ferromagnetic surrounding (photoinduced magnetic polaron), whereas the integral magnetization measured by SQUID is most sensitive to long-range magnetic ordering. In spite of the dissimilarity of measurement techniques we find an influence of the long-range magnetic order (e.g. of the NNS- or NNN-matrix) on the non-resonant Kerr reflection. The complementarity of SQUID and magneto-optical methods is stringent only in the (resonant) spectral range, where magnetic polarons are formed. (author)

  15. Growth and optical development of the ocular lens of the squid (Sepioteuthis lessoniana).

    Science.gov (United States)

    Sivak, J G; West, J A; Campbell, M C

    1994-09-01

    Lens focal properties (spherical aberration), diameter and relative anterior/posterior proportions were measured photographically for Japanese squid (Sepioteuthis lessoniana) at ages 4-6 weeks, 7-9 weeks and 7-8 months. The measures involved photographing the refractive effects of lenses in a physiological solution, with and without an index matching fluid (polyvinylpyrroloidone solution), on a parallel array of fine helium-neon laser beams. Spherical aberration was determined from measurement of back vertex distance. Similar measurements were made on lenses from the eyes of cuttlefish (Sepia officinalis). The cephalopod lens develops as hemispheric halves from separate ectodermal sources. The posterior component contributes, on average, about 60% of axial lens diameter in S. lessoniana of all ages and 55% in S. officinalis. However, these proportions vary widely in both species. All lenses of both species show that spherical aberration is neutralized, although small variations in back vertex distance (positive and negative spherical aberration) were measured. Preliminary measures indicate that the refractive index distribution within the cephalopod lens varies in a manner reminiscent of teleost lenses. Squid lenses from animals 7-9 weeks of age were optimally corrected for spherical aberration. Some squid of this age, from a separate tank, showed a high incidence of cataract development. In each case, lens opacification was caused by deterioration of the posterior lens component.

  16. Assessment of Heavy Metal Contamination in Squid (Loligo Spp.) Tissues of Kedah-Perlis Waters, Malaysia

    International Nuclear Information System (INIS)

    Jamil, T.; Lias, K.; Norsila, D.; Syafinaz, N.S.

    2014-01-01

    This study was carried out to determine the concentration of selected heavy metals (Cd, Cu, Pb and Zn) in three different tissues collected from the ink-sac, head, and muscle of the squid. Squid samples were caught off the coastal waters of Kedah-Perlis, where only mature squids within the maturity size-range of 13 to 15 cm were used. From this study, the concentration of Zn (35.06 ± 4.06 mg/ kg in dry weight) was found significantly higher in all of the tissues, followed by Cu (15.10 ± 13.28 mg/ kg in dry weight), Cd (4.76 ± 3.77 mg/ kg in dry weight), and Pb with an average value of 4.01 ± 0.08 mg/ kg in dry weight. From this study, it was discovered that Zn and Cu concentrations in the tissues were lower than the maximum limit recommended by the Food and Agriculture Organization, Malaysian Food Regulation (1985), as well as other countries. Meanwhile, both non-essential elements namely Cd and Pb recorded higher values than that of the recommended concentrations. According to the Metal Pollution Index (MPI), the ink-sac indicated medium-range contamination, while the head and muscle tissues showed low contamination levels. (author)

  17. SQUID-based Nondestructive Testing Instrument of Dished Niobium Sheets for SRF Cavities

    International Nuclear Information System (INIS)

    Q. S. Shu; I. Ben-Zvi; G. Cheng; I. M. Phipps; J. T. Susta; P. Kneisel; G. Myneni; J. Mast; R. Selim

    2007-01-01

    Currently available technology can only inspect flat sheets and allow the elimination of defective flat sheets before the expensive forming and machining of the SRF cavity half-cells, but it does not eliminate the problem of remaining or uncovered surface impurities after partial chemical etching of the half-cells, nor does it detect any defects that may have been added during the fabrication of the half-cells. AMAC has developed a SQUID scanning system based on eddy current technique that allows the scanning of curved Nb samples that are welded to make superconducting RF cavity half-cells. AMAC SQUID scanning system successfully located the defects (Ta macro particles about 100 mm diameter) in a flat Nb sample (top side) and was able to also locate the defects in a cylindrical surface sample (top side). It is more significant that the system successfully located the defects on the backside of the flat sample and curved sample or 3-mm from the top surface. The 3-D SQUID-based Nondestructive instrument will be further optimized and improved in making SRF cavities and allow inspection and detection during cavity manufacturing for achieving highest accelerating fields

  18. Scanning SQUID microscope with an in-situ magnetization/demagnetization field for geological samples

    Science.gov (United States)

    Du, Junwei; Liu, Xiaohong; Qin, Huafeng; Wei, Zhao; Kong, Xiangyang; Liu, Qingsong; Song, Tao

    2018-04-01

    Magnetic properties of rocks are crucial for paleo-, rock-, environmental-magnetism, and magnetic material sciences. Conventional rock magnetometers deal with bulk properties of samples, whereas scanning microscope can map the distribution of remanent magnetization. In this study, a new scanning microscope based on a low-temperature DC superconducting quantum interference device (SQUID) equipped with an in-situ magnetization/demagnetization device was developed. To realize the combination of sensitive instrument as SQUID with high magnetizing/demagnetizing fields, the pick-up coil, the magnetization/demagnetization coils and the measurement mode of the system were optimized. The new microscope has a field sensitivity of 250 pT/√Hz at a coil-to-sample spacing of ∼350 μm, and high magnetization (0-1 T)/ demagnetization (0-300 mT, 400 Hz) functions. With this microscope, isothermal remanent magnetization (IRM) acquisition and the according alternating field (AF) demagnetization curves can be obtained for each point without transferring samples between different procedures, which could result in position deviation, waste of time, and other interferences. The newly-designed SQUID microscope, thus, can be used to investigate the rock magnetic properties of samples at a micro-area scale, and has a great potential to be an efficient tool in paleomagnetism, rock magnetism, and magnetic material studies.

  19. Preparation and evaluation of squid ink polysaccharide-chitosan as a wound-healing sponge.

    Science.gov (United States)

    Huang, Na; Lin, Jiali; Li, Sidong; Deng, Yifeng; Kong, Songzhi; Hong, Pengzhi; Yang, Ping; Liao, Mingneng; Hu, Zhang

    2018-01-01

    A new type of wound healing agent was developed using two marine biomaterials (squid ink polysaccharide and chitosan) as carriers and calcium chloride as an initiator for coagulation. Based on central composite design-response surface methodology, comprehensive evaluation of appearance quality for composite sponges and water absorbency were used as evaluation indices to identify the optimized preparation conditions and further evaluate the performance of the squid ink polysaccharide-chitosan sponge (SIP-CS). The optimized formulation of SIP-CS was as follows: chitosan concentration, 2.29%; squid ink polysaccharide concentration, 0.55%; and calcium chloride concentration, 2.82%, at a volume ratio of 15:5:2. SIP-CS was conducive to sticking on the wound, characterized by the spongy property, strong absorptivity, and tackiness. Rabbit ear arterial, hepatic, and femoral artery hemorrhage experiments indicated that, compared with chitosan dressings and absorbable gelatin, the hemostatic times were shorter and the bleeding volume was smaller. Furthermore, SIP-CS absorbed a large amount of hemocytes, leading to rapid hemostasis. The healing areas and wound pathological sections in scalded New Zealand rabbits indicated that SIP-CS promoted wound healing more rapidly than chitosan and better than commercially available burn cream. Thus, SIP-CS is a good wound healing agent for rapid hemostasis, promoting burn/scalded skin healing, and protecting from wound infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Greatly improved cache update times for conditions data with Frontier/Squid

    Energy Technology Data Exchange (ETDEWEB)

    Dykstra, Dave; Lueking, Lee, E-mail: dwd@fnal.go [Computing Division, Fermilab, Batavia, IL (United States)

    2010-04-01

    The CMS detector project loads copies of conditions data to over 100,000 computer cores worldwide by using a software subsystem called Frontier. This subsystem translates database queries into HTTP, looks up the results in a central database at CERN, and caches the results in an industry-standard HTTP proxy/caching server called Squid. One of the most challenging aspects of any cache system is coherency, that is, ensuring that changes made to the underlying data get propagated out to all clients in a timely manner. Recently, the Frontier system was enhanced to drastically reduce the time for changes to be propagated everywhere without heavily loading servers. The propagation time is now as low as 15 minutes for some kinds of data and no more than 60 minutes for the rest of the data. This was accomplished by taking advantage of an HTTP and Squid feature called If-Modified-Since. In order to use this feature, the Frontier server sends a Last-Modified timestamp, but since modification times are not normally tracked by Oracle databases, a PL/SQL program was developed to track the modification times of database tables. We discuss the details of this caching scheme and the obstacles overcome including database and Squid bugs.

  1. Chitinolytic Bacteria-Assisted Conversion of Squid Pen and Its Effect on Dyes and Pigments Adsorption

    Directory of Open Access Journals (Sweden)

    Tzu-Wen Liang

    2015-07-01

    Full Text Available The aim of this work was to produce chitosanase by fermenting from squid pen, and recover the fermented squid pen for dye removal by adsorption. One chitosanase induced from squid pen powder (SPP-containing medium by Bacillus cereus TKU034 was purified in high purification fold (441 and high yield of activity recovery (51% by ammonium sulfate precipitation and combined column chromatography. The SDS-PAGE results showed its molecular mass to be around 43 kDa. The TKU034 chitosanase used for the chitooligomers preparation was studied. The enzyme products revealed that the chitosanase could degrade chitosan with various degrees of polymerization, ranging from 3 to 9, as well as the chitosanase in an endolytic manner. Besides, the fermented SPP was recovered and displayed a better adsorption rate (up to 99.5% for the disperse dyes (red, yellow, blue, and black than the water-soluble food colorants, Allura Red AC (R40 and Tartrazine (Y4. The adsorbed R40 on the unfermented SPP and the fermented SPP was eluted by distilled water and 1 M NaOH to confirm the dye adsorption mechanism. The fermented SPP had a slightly higher adsorption capacity than the unfermented, and elution of the dye from the fermented SPP was easier than from the unfermented. The main dye adsorption mechanism of fermented SPP was physical adsorption, while the adsorption mechanism of unfermented SPP was chemical adsorption.

  2. Chitinolytic Bacteria-Assisted Conversion of Squid Pen and Its Effect on Dyes and Pigments Adsorption.

    Science.gov (United States)

    Liang, Tzu-Wen; Lo, Bo-Chang; Wang, San-Lang

    2015-07-23

    The aim of this work was to produce chitosanase by fermenting from squid pen, and recover the fermented squid pen for dye removal by adsorption. One chitosanase induced from squid pen powder (SPP)-containing medium by Bacillus cereus TKU034 was purified in high purification fold (441) and high yield of activity recovery (51%) by ammonium sulfate precipitation and combined column chromatography. The SDS-PAGE results showed its molecular mass to be around 43 kDa. The TKU034 chitosanase used for the chitooligomers preparation was studied. The enzyme products revealed that the chitosanase could degrade chitosan with various degrees of polymerization, ranging from 3 to 9, as well as the chitosanase in an endolytic manner. Besides, the fermented SPP was recovered and displayed a better adsorption rate (up to 99.5%) for the disperse dyes (red, yellow, blue, and black) than the water-soluble food colorants, Allura Red AC (R40) and Tartrazine (Y4). The adsorbed R40 on the unfermented SPP and the fermented SPP was eluted by distilled water and 1 M NaOH to confirm the dye adsorption mechanism. The fermented SPP had a slightly higher adsorption capacity than the unfermented, and elution of the dye from the fermented SPP was easier than from the unfermented. The main dye adsorption mechanism of fermented SPP was physical adsorption, while the adsorption mechanism of unfermented SPP was chemical adsorption.

  3. Greatly improved cache update times for conditions data with Frontier/Squid

    International Nuclear Information System (INIS)

    Dykstra, Dave; Lueking, Lee

    2009-01-01

    The CMS detector project loads copies of conditions data to over 100,000 computer cores worldwide by using a software subsystem called Frontier. This subsystem translates database queries into HTTP, looks up the results in a central database at CERN, and caches the results in an industry-standard HTTP proxy/caching server called Squid. One of the most challenging aspects of any cache system is coherency, that is, ensuring that changes made to the underlying data get propagated out to all clients in a timely manner. Recently, the Frontier system was enhanced to drastically reduce the time for changes to be propagated everywhere without heavily loading servers. The propagation time is now as low as 15 minutes for some kinds of data and no more than 60 minutes for the rest of the data. This was accomplished by taking advantage of an HTTP and Squid feature called If-Modified-Since. In order to use this feature, the Frontier server sends a Last-Modified timestamp, but since modification times are not normally tracked by Oracle databases, a PL/SQL program was developed to track the modification times of database tables. We discuss the details of this caching scheme and the obstacles overcome including database and Squid bugs.

  4. Growth and flagellation of Vibrio fischeri during initiation of the sepiolid squid light organ symbiosis.

    Science.gov (United States)

    Ruby, E G; Asato, L M

    1993-01-01

    A pure culture of the luminous bacterium Vibrio fischeri is maintained in the light-emitting organ of the sepiolid squid Euprymna scolopes. When the juvenile squid emerges from its egg it is symbiont-free and, because bioluminescence is part of an anti-predatory behavior, therefore must obtain a bacterial inoculum from the surrounding environment. We document here the kinetics of the process by which newly hatched juvenile squids become infected by symbiosis-competent V. fischeri. When placed in seawater containing as few as 240 colony-forming-units (CFU) per ml, the juvenile became detectably bioluminescent within a few hours. Colonization of the nascent light organ was initiated with as few as 1 to 10 bacteria, which rapidly began to grow at an exponential rate until they reached a population size of approximately 10(5) cells by 12 h after the initial infection. Subsequently, the number of bacteria in the established symbiosis was maintained essentially constant by a combination of both a > 20-fold reduction in bacterial growth rate, and an expulsion of excess bacteria into the surrounding seawater. While V. fischeri cells are normally flagellated and motile, these bacteria did not elaborate these appendages once the symbiosis was established; however, they quickly began to synthesize flagella when they were removed from the light organ environment. Thus, two important biological characteristics, growth rate and flagellation, were modulated during establishment of the association, perhaps as part of a coordinated series of symbiotic responses.

  5. Ultraviolet Laser SQUID Microscope for GaN Blue Light Emitting Diode Testing

    International Nuclear Information System (INIS)

    Daibo, M; Kamiwano, D; Kurosawa, T; Yoshizawa, M; Tayama, N

    2006-01-01

    We carried out non-contacting measurements of photocurrent distributions in GaN blue light emitting diode (LED) chips using our newly developed ultraviolet (UV) laser SQUID microscope. The UV light generates the photocurrent, and then the photocurrent induces small magnetic fields around the chip. An off-axis arranged HTS-SQUID magnetometer is employed to detect a vector magnetic field whose typical amplitude is several hundred femto-tesla. Generally, it is difficult to obtain Ohmic contacts for p-type GaN because of the low hole concentration in the p-type epitaxial layer and the lack of any available metal with a higher work function compared with the p-type GaN. Therefore, a traditional probecontacted electrical test is difficult to conduct for wide band gap semiconductors without an adequately annealed electrode. Using the UV-laser SQUID microscope, the photocurrent can be measured without any electrical contact. We show the photocurrent vector map which was reconstructed from measured magnetic fields data. We also demonstrate how we found the position of a defect of the electrical short circuits in the LED chip

  6. HTS-SQUID NDE Technique for Pipes based on Ultrasonic Guided Wave

    Science.gov (United States)

    Hatsukade, Y.; Masutani, N.; Teranishi, S.; Masamoto, K.; Kanenaga, S.; Adachi, S.; Tanabe, K.

    2017-07-01

    This article describes research on the novel high-temperature superconductor (HTS) superconducting quantum interference device (SQUID) non-destructive evaluation (NDE) technique for metallic pipes based on ultrasonic guided waves. We constructed HTS-SQUID NDE system for pipes based on ultrasonic guided waves, which were generated and received by means of the magnetostrictive effects. Using the system, we measured magnetic signals due to T (0, 1) mode ultrasonic guided waves that transmitted on aluminium pipe, and investigated influences of measurement parameters to the magnetic signals, such as direction of a HTS-SQUID gradiometer, lift-off distance, and intensity and frequency of input current fed to a magnetostrictive transmitter. With the gradiometer oriented parallel to the pipe axis, more than 10 times larger signals were measured compared with that oriented perpendicular to the pipe axis. Magnetic signals measured by the gradiometer were inverse proportional to the power of the list- off distance, and proportional to the intensity of the input current up to 1 App. Relation between the frequency of the input current and the measured signal was shown and discussed.

  7. Development of non-destructive evaluation system using an HTS-SQUID gradiometer for magnetized materials

    Science.gov (United States)

    Kawano, J.; Tsukamoto, A.; Adachi, S.; Oshikubo, Y.; Hato, T.; Tanabe, K.; Okamura, T.

    We have developed a new eddy-current non-destructive evaluation (NDE) system using an HTS SQUID gradiometer with the aim of applying it to practical materials with magnetization. The new NDE system employs a LN2-cooled external Cu pickup coil and an HTS SQUID chip placed in a magnetic shield made of HTS material. The HTS SQUID chip consists of an HTS planar gradiometer manufactured by using a ramp-edge junction technology and a multi-turn HTS thin film input coil coupled with the flip-chip configuration. The first-order coaxial gradiometric Cu pickup coil with a diameter of 16 mm and the baseline of 5.6 mm was used in the present NDE experiments. By using this NDE system, we could observe defect-induced magnetic signals without an appreciable influence of magnetization up to 10 mT. We also examined the ability of detecting deep-lying defects and compared with the results obtained using our previous NDE system.

  8. Design and Characterization of Low-noise Dewar for High-sensitivity SQUID Operation

    International Nuclear Information System (INIS)

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

    2010-01-01

    We have fabricated the low noise liquid helium(LHe) dewar with a different shape of thermal shield to apply the 64-channel SQUID(Superconducting Quantum Interference Device) gradiometer. The first shape of thermal shield was made of an aluminum plate with a wide width of 100 mm slit and the other shape was modified with a narrow width of 20 mm slit. The two types of dewars were estimated by comparing the thermal noise and the signal-to-noise ratio(SNR) of magnetocardiography(MCG) using the 1st order SQUID gradiometer system cooled each dewar. The white noise was different as a point of the dewar. The noise was increased as close as the edge of dewar, and also increased at the thermal shield with the more wide width slit. The white noise of the dewar with thermal shield of 100 mm slit was 6.5 fT/Hz 1/2 at the center of dewar and 25 fT/Hz 1/2 at the edge, and the white noise of the other one was 3.5 - 7 fT/Hz 1/2 . We measured the MCG using 64-channel SQUID gradiometer cooled at each LHe dewar and compared the SNR of MCG signal. The SNR was improved of 10 times at the LHe dewar with a modified thermal shield.

  9. Chitinolytic Bacteria-Assisted Conversion of Squid Pen and Its Effect on Dyes and Pigments Adsorption

    Science.gov (United States)

    Liang, Tzu-Wen; Lo, Bo-Chang; Wang, San-Lang

    2015-01-01

    The aim of this work was to produce chitosanase by fermenting from squid pen, and recover the fermented squid pen for dye removal by adsorption. One chitosanase induced from squid pen powder (SPP)-containing medium by Bacillus cereus TKU034 was purified in high purification fold (441) and high yield of activity recovery (51%) by ammonium sulfate precipitation and combined column chromatography. The SDS-PAGE results showed its molecular mass to be around 43 kDa. The TKU034 chitosanase used for the chitooligomers preparation was studied. The enzyme products revealed that the chitosanase could degrade chitosan with various degrees of polymerization, ranging from 3 to 9, as well as the chitosanase in an endolytic manner. Besides, the fermented SPP was recovered and displayed a better adsorption rate (up to 99.5%) for the disperse dyes (red, yellow, blue, and black) than the water-soluble food colorants, Allura Red AC (R40) and Tartrazine (Y4). The adsorbed R40 on the unfermented SPP and the fermented SPP was eluted by distilled water and 1 M NaOH to confirm the dye adsorption mechanism. The fermented SPP had a slightly higher adsorption capacity than the unfermented, and elution of the dye from the fermented SPP was easier than from the unfermented. The main dye adsorption mechanism of fermented SPP was physical adsorption, while the adsorption mechanism of unfermented SPP was chemical adsorption. PMID:26213948

  10. SQUID multiplexing using baseband feedback for space application of transition-edge sensor microcalorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Takei, Y; Yamasaki, N Y; Hirakoso, W; Kimura, S; Mitsuda, K, E-mail: takei@astro.isas.jaxa.j [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, 229-8510 (Japan)

    2009-11-15

    A microcalorimeter array based on a transition-edge sensor (TES) thermometer is a promising imaging spectrometer for use in future x-ray astronomy missions. A TES microcalorimeter achieves {approx}<5 eV energy resolution and an array of >100 pixels also provides a moderate imaging capability. For a large format array, signal multiplexing at the low temperature stage is mandatory in order to reduce heat loads from cold stage preamplifiers and through wirings. We are developing frequency division multiplexing (FDM). In FDM, each TES is ac-biased with a different carrier frequency. Signals from several pixels are summed and then read out by one dc SQUID (superconducting quantum interference device). The maximum number of multiplexed pixels is limited by the bandwidth of a SQUID in a flux-locked loop. Assuming 1 m cable length between the room temperature and the cold stage, the bandwidth is only <1 MHz with a standard flux-locked loop, due to the delay and phase shift of wirings. We report our development of baseband feedback, a new feedback scheme that overcomes the bandwidth limitation. In baseband feedback, the signal ({approx}<10 kHz) from the TES is sent back to the SQUID after the phase of carrier frequency ({approx}1 MHz) has been adjusted. We demonstrated open-loop gain of 8 for 10 kHz signal at 5 MHz carrier frequency, which indicates the possibility of {approx}40-pixel multiplexing of the TES signal.

  11. Temperature profiles from MBT casts from the HUMBOLDT from Ocean Weather Station D (OWS-D) in the North Atlantic Ocean from 1962-07-13 to 1962-08-05 (NODC Accession 6200130)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the HUMBOLDT within a 1-mile radius of Ocean Weather Station D (4400N 04100W) and in transit. Data were collected by the...

  12. Temperature profiles from MBT casts from the HUMBOLDT from Ocean Weather Station B (OWS-B) in the North Atlantic Ocean from 1968-07-21 to 1968-08-12 (NODC Accession 6800388)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the HUMBOLDT within a 1-mile radius of Ocean Weather Station B (5630N 05100W) and in transit. Data were collected by the...

  13. Temperature profiles from MBT casts from the HUMBOLDT from Ocean Weather Station E (OWS-E) in the North Atlantic Ocean from 1962-09-18 to 1962-10-13 (NODC Accession 6200206)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the HUMBOLDT within a 1-mile radius of Ocean Weather Station E (3500N 04800W) and in transit. Data were collected by the...

  14. Temperature profiles from MBT casts from the HUMBOLDT from Ocean Weather Station C (OWS-C) in the North Atlantic Ocean from 1963-05-26 to 1963-06-24 (NODC Accession 6300123)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the HUMBOLDT within a 1-mile radius of Ocean Weather Station C (5245N 0350W) and in transit. Data were collected by the...

  15. Temperature profiles from MBT casts from the HUMBOLDT from Ocean Weather Station B (OWS-B) in the North Atlantic Ocean from 1966-03-17 to 1966-04-01 (NODC Accession 6600372)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the HUMBOLDT within a 1-mile radius of Ocean Weather Station B (56305N 05100W) and in transit. Data were collected by the...

  16. Temperature profiles from MBT casts from the HUMBOLDT from Ocean Weather Station D (OWS-D) in the North Atlantic Ocean from 1966-05-28 to 1966-06-24 (NODC Accession 6600371)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the HUMBOLDT within a 1-mile radius of Ocean Weather Station D (4400N 04100W) and in transit. Data were collected by the...

  17. Oceanographic profile plankton, Temperature Salinity and other measurements collected using bottle from VICTORIA 1 FISHING BOAT), ALEJERO HUMBOLDT and other platforms in the South Pacific, Coastal S Pacific and other locations from 1980 to 1982 (NODC Accession 0002083)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other measurements found in dataset OSD taken from the VICTORIA 1(FISHING BOAT), ALEJERO HUMBOLDT and other platforms in the South...

  18. ULF-NMR system using HTS-SQUID and permanent magnet

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, Shohei, E-mail: hatukade@ens.tut.ac.jp [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Tsunaki, Shingo; Chigasaki, Takumi; Hatsukade, Yoshimi; Tanaka, Saburo [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)

    2013-01-15

    Highlights: ► A permanent magnet was introduced into a ULF SQUID-NMR system for polarization. ► An instrument to transfer a sample in the magnet to under a SQUID was implemented. ► An AC pulse coil was also introduced to apply a π/2 pulse to obtain an NMR signal. ► A {sup 1}H NMR signal was measured while applying a static field of 45 μT. ► The signal to noise ratio of the {sup 1}H NMR signal was about 100. -- Abstract: We have constructed an ultra-low field (ULF) nuclear magnetic resonance (NMR)/magnetic resonance imaging (MRI) system using an HTS-rf-SQUID and room-temperature electromagnets in a magnetically shielded room (MSR). In this study, in order to improve the signal to noise ratio (S/N) of the system, we introduced a permanent magnet instead of the electromagnet for pre-polarizing the sample to enhance the pre-polarizing field (B{sub p}). The cylindrical permanent magnet of 270 mT was used to magnetize a water sample for several seconds outside the MSR and about 1.5 m away from the SQUID. We constructed an instrument to transfer the magnetized sample from the permanent magnet to under the SQUID in 0.5 s. Since the non-adiabatic condition cannot be kept in such sample transfer scheme, an AC pulse coil to apply an AC pulse field B{sub AC} to rotate the magnetization moments for π/2 was introduced to measure a free induction decay (FID) signal from the sample. By this system, we obtained an NMR signal from the water sample of 10 ml while applying a static field of 45 μT and π/2 pulse after the transfer. The S/N of the NMR spectrum was about 100 by a single shot, which was 10 times larger than that obtained with the electromagnet of 32 mT. In addition, we demonstrated the measurements of the longitudinal relaxation time (T{sub 1}) and the spin echo signal of the water sample by the system.

  19. High-resolution imaging of magnetic fields using scanning superconducting quantum interference device (SQUID) microscopy

    Science.gov (United States)

    Fong de Los Santos, Luis E.

    Development of a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with sub-millimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensor is mounted in the tip of a sapphire rod and thermally anchored to the cryostat helium reservoir. A 25 mum sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows adjusting the sample-to-sensor spacing from the top of the Dewar. I have achieved a sensor-to-sample spacing of 100 mum, which could be maintained for periods of up to 4 weeks. Different SQUID sensor configurations are necessary to achieve the best combination of spatial resolution and field sensitivity for a given magnetic source. For imaging thin sections of geological samples, I used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80 mum, and achieved a field sensitivity of 1.5 pT/Hz1/2 and a magnetic moment sensitivity of 5.4 x 10-18 Am2/Hz1/2 at a sensor-to-sample spacing of 100 mum in the white noise region for frequencies above 100 Hz. Imaging action currents in cardiac tissue requires higher field sensitivity, which can only be achieved by compromising spatial resolution. I developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250 mum to 1 mm, and achieved sensitivities of 480 - 180 fT/Hz1/2 in the white noise region for frequencies above 100 Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of

  20. Plan for SQUID microscope at ASRC: Vision, purposes and the present status

    International Nuclear Information System (INIS)

    Kadowaki, K.; Kakeya, I.; Suzuki, J.; Hata, Y.; Hojyo, K

    2001-01-01

    A new research plan to develop SQUID microscope and apply it to advanced science and technology research was started in the year of 2000 at the Advanced Science Research Center (ASRC) of JAERI (Japan Atomic Energy Research Institute). This plan was made to develop 'research of ultrafine magnetic structures with magnetic microscope' and is scheduled to continue five years. Principle of SQUID magnetic microscope is to observe changes of magnetic field in microscopic space using SQUID element as the magnetic probe. At present this type of instrument is fabricated by Seiko Instruments Inc. in Japan and is commercially available. Therefore, this plan is being promoted in collaboration with Seiko Instruments Inc. One of the main issues of the present plan is to raise the spatial resolution to the extremity. As of magnetic microscopes, 'magnetic force microscope' and 'scanning Hall probe microscope' also exist. They have different characteristics of their own. The present plan needs challenging technical developments in various fields. Supposed the spatial resolution be made very high, for example, by making very fine SQUID loop with ultrafine processing, critical technologies like sensitivity, electronics, quantum size effect and so on are to be solved at the same time. Characteristics of the existing instrument are being examined from various aspects. At present, the following three issues are taken up and being studied. (1) High resolution and related technical developments. (2) High sensitivity. (3) High performance of cooling system. Among them, the high resolution is the most serious problem. Completely new design of the SQUID system may be needed. By using the existing instrument, magnetic fluxes trapped on YBCO films are observed and the image quality is being examined. Some of the issues which are considered to be taken up now are listed as follows. (1) Magnetic domain structures on thin film magnetic materials. (2) Observation of structures of Josephson magnetic

  1. Emulsifying and gelling properties of weakfish myofibrillar proteins as affected by squid mantle myofibrillar proteins in a model system

    Directory of Open Access Journals (Sweden)

    Daniela Mariel Suarez

    2014-03-01

    Full Text Available The aim of the present work was to investigate the physicochemical, biochemical and functional characteristics of both the myofibrils (MF and actomyosin (AM of squid mantle (Illex argentinus and weakfish (Cynoscion guatucupa muscles, and evaluate the influence of the addition of myofibrilar proteins from the squid mantle on the physicochemical and functional properties of those of the weakfish. After extraction, purification and characterization of the MF and AM of both species, emulsions of each protein fraction from each muscle were formulated. Mixtures of the MF or AM of both species were also analyzed. The emulsifying properties were monitoring using the Emulsifying Activity Index (EAI and Emulsion Stability (ES. In addition, gel pastes were formulated from the squid mantle, weakfish muscle and the mixture of both species, and the following functional properties of the gels assessed: water holding capacity, colour, textural profile analysis (TPA (hardness, elasticity, cohesiveness, gumminess and gel strength. The EAI values of emulsions formulated with the MF of the mantle were significantly (p<0.05 higher than those formulated from those of weakfish. The incorporation of squid MF in the mixture increased the EAI values. Conversely, the highest ES values were obtained with weakfish MF, and the incorporation of MF weakfish in the mixture increased the ES values. Similar EAI and ES behaviours were observed for the AM of the corresponding species. Irrespective of the thermal treatment, the gel strength of the gelled paste of squid muscle was significantly (p<0.05 lower than that of weakfish muscle and of those obtained with the different mixtures. The behaviours of the expressible moisture (EM from the gelled pastes were similar to those of gel strength. Irrespective of the thermal treatment, the pastes formulated with a high weakfish: mantle ratio showed less water loss. The gelled pastes of squid mantle showed the highest values for whiteness

  2. Sensitivity of the Humboldt current system to global warming: a downscaling experiment of the IPSL-CM4 model

    Energy Technology Data Exchange (ETDEWEB)

    Echevin, Vincent [LOCEAN, Paris (France); Goubanova, Katerina; Dewitte, Boris [LEGOS, Toulouse (France); IMARPE, IGP, LEGOS, Lima (Peru); Belmadani, Ali [LOCEAN, Paris (France); LEGOS, Toulouse (France); University of Hawaii at Manoa, IPRC, International Pacific Research Center, SOEST, Honolulu, Hawaii (United States)

    2012-02-15

    The impact of climate warming on the seasonal variability of the Humboldt Current system ocean dynamics is investigated. The IPSL-CM4 large scale ocean circulation resulting from two contrasted climate scenarios, the so-called Preindustrial and quadrupling CO{sub 2}, are downscaled using an eddy-resolving regional ocean circulation model. The intense surface heating by the atmosphere in the quadrupling CO{sub 2} scenario leads to a strong increase of the surface density stratification, a thinner coastal jet, an enhanced Peru-Chile undercurrent, and an intensification of nearshore turbulence. Upwelling rates respond quasi-linearly to the change in wind stress associated with anthropogenic forcing, and show a moderate decrease in summer off Peru and a strong increase off Chile. Results from sensitivity experiments show that a 50% wind stress increase does not compensate for the surface warming resulting from heat flux forcing and that the associated mesoscale turbulence increase is a robust feature. (orig.)

  3. De la biogeografía al paisaje en Humboldt: pisos de vegetación y paisajes andinos equinocciales

    Directory of Open Access Journals (Sweden)

    Concepción Sanz Herráiz

    2010-03-01

    Full Text Available The current recovery of the notion of landscape as a means of comprehending the relationships between nature, society and culture in their spatiotemporal dimensions, that is, as specifi c totalities, calls for a return to its most fecund presentations, beginning with what is perhaps the most outstanding version of them all, that of Alexander von Humboldt. On this occasion we intend to make a reading in terms of landscape of Essay on the Geography of Plants and of the accompanying Physical Tableau, the one of humboldtian works less known. We believe that our study will demonstrate that Humboldt’s contribution on landscape and landscapes was to a great extent contained in the initial text of Geography of Plants; which in turn enables us to explore the fundamental relationship between landscape and the initial development of Biogeography.

  4. Influence of thermal discharges on the distribution of macroflora and fauna. Humboldt Bay Nuclear Power Plant, California

    International Nuclear Information System (INIS)

    Adams, J.R.

    1975-01-01

    Populations of benthic and epifaunal macro-organisms living in the area influenced by the thermal discharge of the steam-electric power plant at Humboldt Bay, California, were analyzed in 1971 and 1972 to determine if differences in distribution could be attributed to the effluent. Relicated benthic samples were collected with a Ponar grab at 20 stations in the bay and at 4 stations in the canals leading to and from the power plant. Comparisons of epifaunal plants and animals in a rocky intertidal zone were made at 13 permanent transects spaced at various distances on either side of the discharge. Species richness in the intertidal was positively correlated with increased temperature in 13 percent of the possible combinations of tide level and diversity. Individual species were positively correlated with increased temperatures for 19 percent of the plant comparisons, and for 16.3 percent of the animal comparisons. Comparisons of populations of individual species in the heated intertidal zone with those in a control zone indicated differences in 26.2 percent of the plant surveys, and 23.2 percent of the animal surveys. Differences were positively related to the increased temperature in 90.5 percent of the comparisons. Proportions of eurythermal plants or animals in the heated areas of the intertidal zone did not differ significantly from proportions in other areas in 4 different survey periods. With the possible exception of one species, there was no conclusive evidence that any of the 132 species found in the intertidal area at Humboldt Bay was eliminated from the heated area surrounding the discharge of the power plant

  5. Genomic features of "Candidatus Venteria ishoeyi", a new sulfur-oxidizing macrobacterium from the Humboldt Sulfuretum off Chile.

    Directory of Open Access Journals (Sweden)

    Alexis Fonseca

    Full Text Available The Humboldt Sulfuretum (HS, in the productive Humboldt Eastern Boundary Current Upwelling Ecosystem, extends under the hypoxic waters of the Peru-Chile Undercurrent (ca. 6°S and ca. 36°S. Studies show that primeval sulfuretums held diverse prokaryotic life, and, while rare today, still sustain species-rich giant sulfur-oxidizing bacterial communities. We here present the genomic features of a new bacteria of the HS, "Candidatus Venteria ishoeyi" ("Ca. V. ishoeyi" in the family Thiotrichaceae.Three identical filaments were micro-manipulated from reduced sediments collected off central Chile; their DNA was extracted, amplified, and sequenced by a Roche 454 GS FLX platform. Using three sequenced libraries and through de novo genome assembly, a draft genome of 5.7 Mbp, 495 scaffolds, and a N50 of 70 kbp, was obtained. The 16S rRNA gene phylogenetic analysis showed that "Ca. V. ishoeyi" is related to non-vacuolate forms presently known as Beggiatoa or Beggiatoa-like forms. The complete set of genes involved in respiratory nitrate-reduction to dinitrogen was identified in "Ca. V. ishoeyi"; including genes likely leading to ammonification. As expected, the sulfur-oxidation pathway reported for other sulfur-oxidizing bacteria were deduced and also, key inorganic and organic carbon acquisition related genes were identified. Unexpectedly, the genome of "Ca. V. ishoeyi" contained numerous CRISPR repeats and an I-F CRISPR-Cas type system gene coding array. Findings further show that, as a member of an eons-old marine ecosystem, "Ca. V. ishoeyi" contains the needed metabolic plasticity for life in an increasingly oxygenated and variable ocean.

  6. Chronic Treatment with Squid Phosphatidylserine Activates Glucose Uptake and Ameliorates TMT-Induced Cognitive Deficit in Rats via Activation of Cholinergic Systems

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Park

    2012-01-01

    Full Text Available The present study examined the effects of squid phosphatidylserine (Squid-PS on the learning and memory function and the neural activity in rats with TMT-induced memory deficits. The rats were administered saline or squid derived Squid-PS (Squid-PS 50 mg kg−1, p.o. daily for 21 days. The cognitive improving efficacy of Squid-PS on the amnesic rats, which was induced by TMT, was investigated by assessing the passive avoidance task and by performing choline acetyltransferase (ChAT and acetylcholinesterase (AchE immunohistochemistry. 18F-Fluorodeoxyglucose and performed a positron emission tomography (PET scan was also performed. In the passive avoidance test, the control group which were injected with TMT showed a markedly lower latency time than the non-treated normal group (P<0.05. However, treatment of Squid-PS significantly recovered the impairment of memory compared to the control group (P<0.05. Consistent with the behavioral data, Squid-PS significantly alleviated the loss of ChAT immunoreactive neurons in the hippocampal CA3 compared to that of the control group (P<0.01. Also, Squid-PS significantly increased the AchE positive neurons in the hippocampal CA1 and CA3. In the PET analysis, Squid-PS treatment increased the glucose uptake more than twofold in the frontal lobe and the hippocampus (P<0.05, resp.. These results suggest that Squid-PS may be useful for improving the cognitive function via regulation of cholinergic enzyme activity and neural activity.

  7. Seasonal Habitat Patterns of Japanese Common Squid (Todarodes Pacificus Inferred from Satellite-Based Species Distribution Models

    Directory of Open Access Journals (Sweden)

    Irene D. Alabia

    2016-11-01

    Full Text Available The understanding of the spatio-temporal distributions of the species habitat in the marine environment is central to effectual resource management and conservation. Here, we examined the potential habitat distributions of Japanese common squid (Todarodes pacificus in the Sea of Japan during a four-year period. The seasonal patterns of preferential habitat were inferred from species distribution models, built using squid occurrences detected from night-time visible images and remotely-sensed environmental factors. The predicted squid habitat (i.e., areas with high habitat suitability revealed strong seasonal variability, characterized by a reduction of potential habitat, confined off of the southern part of the basin during the winter–spring period (December–May. Apparent expansion of preferential habitat occurred during summer–autumn months (June–November, concurrent with the formation of highly suitable habitat patches in certain regions of the Sea of Japan. These habitat distribution patterns were in response to changes in oceanographic conditions and synchronous with seasonal migration of squid. Moreover, the most important variables regulating the spatio-temporal patterns of suitable habitat were sea surface temperature, depth, sea surface height anomaly, and eddy kinetic energy. These variables could affect the habitat distributions through their impacts on growth and survival of squid, local nutrient transport, and the availability of favorable spawning and feeding grounds.

  8. Effects of November 8, 1980 earthquake on Humboldt Bay Power Plant and Eureka, California area. Reconnaissance report 13 Nov-14 Nov 80

    International Nuclear Information System (INIS)

    Herring, K.S.; Rooney, V.; Chokshi, N.C.

    1981-06-01

    On November 8, 1980, an earthquake of a reported surface wave magnitude of 7.0 occurred off the coast of California, west of Eureka and the Humboldt Bay Power Plant. Three NRC staff members visited the site the following week to survey any damage associated with the earthquake, with the objective of using collected data to assist the NRR staff in ongoing seismic evaluations of older operating nuclear power plant facilities. This report contains their observations. They concluded that the effects of the earthquake on Humboldt Bay Power Plant Unit 3 were minimal and did not endanger the health and safety of the public. They recommended that improvements be made to seismic recording equipment and that generic preparation for future post-earthquake reconnaissance trips be made before the actual occurrence of earthquakes

  9. Le Cosmos d'Alexandre von Humboldt et La Tentation de saint Antoine de Gustave Flaubert : deux œuvres de toute une vie

    OpenAIRE

    Mary Orr

    2010-01-01

    Dans le septième et dernier tableau de La Tentation de saint Antoine de 1874, la fin célèbre est mise en contexte par une description longue et détaillée qui n’a jamais attiré l’attention critique qu’elle mérite. Cet article analyse l’importance de ce panorama du monde naturel sous la forme d’une exploration intertextuelle des passages du Cosmos d’Alexandre de Humboldt. Que Flaubert signale ses lectures de l’œuvre de Humboldt dans sa Correspondance de 1860 suggère des liens très riches entre ...

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

    Science.gov (United States)

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

    2018-02-01

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

  11. Flux-coherent series SQUID array magnetometers operating above 77 K with superior white flux noise than single-SQUIDs at 4.2 K

    Energy Technology Data Exchange (ETDEWEB)

    Chesca, Boris, E-mail: B.Chesca@lboro.ac.uk; John, Daniel [Department of Physics, Loughborough University, Loughborough LE11 3TU (United Kingdom); Mellor, Christopher J. [School of Physics and Astronomy, Nottingham University, Nottingham NG7 2RD (United Kingdom)

    2015-10-19

    A very promising direction to improve the sensitivity of magnetometers based on superconducting quantum interference devices (SQUIDs) is to build a series-array of N non-interacting SQUIDs operating flux-coherently, because in this case their voltage modulation depth, ΔV, linearly scales with N whereas the white flux noise S{sub Φ}{sup 1/2} decreases as 1/N{sup 1/2}. Here, we report the realization of both these improvements in an advanced layout of very large SQUID arrays made of YBa{sub 2}Cu{sub 3}O{sub 7}. Specially designed with large area narrow flux focusers for increased field sensitivity and improved flux-coherency, our arrays have extremely low values for S{sub Φ}{sup 1/2} between (0.25 and 0.44) μΦ{sub 0}/Hz{sup 1/2} for temperatures in the range (77–83) K. In this respect, they outperform niobium/aluminium trilayer technology-based single-SQUIDs operating at 4.2 K. Moreover, with values for ΔV and transimpedance in the range of (10–17) mV and (0.3–2.5) kΩ, respectively, a direct connection to a low-noise room temperature amplifier is allowed, while matching for such readout is simplified and the available bandwidth is greatly increased. These landmark performances suggest such series SQUID arrays are ideal candidates to replace single-SQUIDs operating at 4.2 K in many applications.

  12. 个体生长对秘鲁外海茎柔鱼角质颚形态变化的影响%Effect of individual growth on beak morphometry of jumbo flying squid, Dosidicus gigas off the Peruvian Exclusive Economic Zone

    Institute of Scientific and Technical Information of China (English)

    胡贯宇; 陈新军; 方舟

    2016-01-01

    为研究个体生长对茎柔鱼角质颚形态变化的影响,本研究根据2009-2014年中国鱿钓船在秘鲁外海(79°22′~84°30′W、10°00′~18°16′S)采集的茎柔鱼样本,提取出1208尾茎柔鱼的角质颚,对角质颚的12项外部形态进行测量,并利用角质颚微结构的生长纹来估算茎柔鱼的日龄,采用方差分析法(ANOVA)分析了不同胴长组、不同日龄组以及不同性成熟阶段角质颚主要外部形态特征的差异.结果表明,角质颚各形态参数在雌、雄个体间的差异性极显著(P<0.01),且雌性个体的角质颚大于雄性个体.最小显著差多重比较法(LSD)结果显示,在不同胴长组、不同日龄组和不同性成熟阶段,雌、雄个体角质颚的生长存在差异,相同性别个体角质颚不同部位的生长也不同;在胴长大于400 mm、雌性个体大于300日龄、雄性个体大于250日龄以及性腺成熟度在Ⅲ期以后时,角质颚的生长较为缓慢.研究表明,个体大小、日龄和性成熟对茎柔鱼角质颚的形态变化有一定的影响.

  13. Intense Ultrasonic clicks from echolocating toothed whales do not elicit anti-predator responses or debilitate the squid Loligo pealeii

    DEFF Research Database (Denmark)

    Wilson, Maria; Hanlon, Roger; Tyack, Peter

    2007-01-01

    an evolutionary selection pressure on cephalopods to develop a mechanism for detecting and evading sound-emitting toothed whale predators. Ultrasonic detection has evolved in some insects to avoid echolocating bats, and it can be hypothesized that cephalopods might have evolved similar ultrasound detection...... as an anti-predation measure. We test this hypothesis in the squid Loligo pealeii in a playback experiment using intense echolocation clicks from two squid-eating toothed whale species. Twelve squid were exposed to clicks at two repetition rates (16 and 125 clicks per second) with received sound pressure...... levels of 199-226dBre1μPa (pp) mimicking the sound exposure from an echolocating toothed whale as it approaches and captures prey. We demonstrate that intense ultrasonic clicks do not elicit any detectable anti-predator behaviour in L. pealeii and that clicks with received levels up to 226dBre1μPa (pp...

  14. Alexander von Humboldt im Spiegel der spanischen Presse. Zur Wahrnehmung seiner Person und seiner Ideen während der ersten Hälfte des 19. Jahrhunderts

    Directory of Open Access Journals (Sweden)

    Sandra Rebok

    2002-04-01

    Full Text Available Article in German, Abstracts in English, Spanish and German.This article shows the image of Alexander von Humboldt that was created in the Spanish press, both in his professional career and his personal life, from his departure to America in 1799, until his death in 1859. This kind of analysis needs to look into two topics: firstly, the aspects of his personality, his life, his work and his ideas mentioned or emphasized in publications published in those years and secondly, the facets that are not shown; both aspects will form the image that the authors intended to project.In both cases this essay attempts to interpret the intentions that might have been behind the «focus» used by the different publications. As part of this analysis, special importance has been given to the importance attributed to Humboldt in relation to two important events: the Spanish American colonial movement for independence and the beginning of what is nowadays called «modernity».This phase of Spanish History coincides with a changing and complex political-social context, which explains the need to consider not only the moderate press published in Spain under absolutist censorship, but also to include the liberal press of the opposition leaders exiled in London, in order to be able to see the different perception that these papers offered of Alexander von Humboldt.

  15. A novel squid pen chitosan/hydroxyapatite/β-tricalcium phosphate composite for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shavandi, Amin, E-mail: amin.shavandi@postgrad.otago.ac.nz [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Department of Applied Sciences, University of Otago, Dunedin (New Zealand); Bekhit, Alaa El-Din A. [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Sun, Zhifa; Ali, Azam [Department of Physics, University of Otago, Dunedin (New Zealand); Gould, Maree [Department of Anatomy, University of Otago, Dunedin (New Zealand)

    2015-10-01

    Squid pen chitosan was used in the fabrication of biocomposite scaffolds for bone tissue engineering. Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) obtained from waste mussel shells were used as the calcium phosphate source. The composite was prepared using 2.5% tripolyphosphate (TPP) and 1% glycerol as a cross-linker and plasticizer, respectively. The weight percent (wt.%) ratios of the ceramic components in the composite were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/Chi). The biodegradation rate and structural properties of the scaffolds were investigated. Scanning electron microscopy (SEM) and microCT(μCT) results indicated that the composites have a well defined lamellar structure with an average pore size of 200 μm. The porosity of the composites decreased from 88 to 56% by increasing the ratio of HA/β-TCP from 30 to 70%. After 28 days of incubation in a physiological solution, the scaffolds were degraded by approximately 30%. In vitro investigations showed that the composites were cytocompatible and supported the growth of L929 and Saos-2 cells. The obtained data suggests that the squid pen chitosan composites are potential candidates for bone regeneration. - Highlights: • Biocomposite scaffolds were made from mussel shells HA and β-TCP, and squid pin chitosan. • The porosity of the composites decreased with an increase in HA/β-TCP ratio. • Composites were cytocompatible and supported the growth of L929 and Saos-2 cells. • Composite containing 50% HA and β-TCP had the best mechanical properties.

  16. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    Science.gov (United States)

    Bechstein, S.; Petsche, F.; Scheiner, M.; Drung, D.; Thiel, F.; Schnabel, A.; Schurig, Th

    2006-06-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-Tc dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm × 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm × 4 cm × 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

  17. Dimorphic ejaculates and sperm release strategies associated with alternative mating behaviors in the squid.

    Science.gov (United States)

    Apostólico, Lígia H; Marian, José E A R

    2017-11-01

    Sperm competition is a powerful postcopulatory selective force influencing male adaptations associated with increasing fertilization success, and it is usually related to the evolution of different strategies of ejaculate expenditure between individuals. Ejaculates may also be influenced by additional selective pressures associated with sperm competition, such as timing between insemination and fertilization, female reproductive tract morphology, and fertilization environment. Also, males that adopt alternative mating tactics may face distinct sperm competition pressures, which may lead to the evolution of intraspecific diversity in ejaculates. In loliginid squids, males with alternative reproductive tactics (sneakers and consorts) differ not only in mating behavior, but also transfer spermatophores into two distinct sites within the female. Here, we compared structure and functioning of spermatophores between sneakers and consorts in the squid Doryteuthis plei applying microscopy techniques and in vitro experiments. Sneakers and consorts exhibit differences in spermatophore structure that lead to distinct spermatophoric reactions and spermatangium morphologies. Moreover, in sneakers, sperm release lasts longer and their sperm show an aggregative behavior not detected in consorts. Slow sperm release may be a strategy to guarantee longer sperm provision, given the wide interval between sneaker mating and egg release. For consorts, in turn, intense and quick sperm discharge may be advantageous, as timing between mating and egg-laying is relatively short. Within the complex squid mating system, factors such as (i) different fertilization sites and (ii) interval between mating and egg release may also influence sperm competition, and ultimately shape the evolution of divergent ejaculates between dimorphic males. © 2017 Wiley Periodicals, Inc.

  18. CO2-level Dependent Effects of Ocean Acidification on Squid, Doryteuthis pealeii, Early Life History

    KAUST Repository

    Zakroff, Casey J.

    2013-12-01

    Ocean acidification is predicted to lead to global oceanic decreases in pH of up to 0.3 units within the next 100 years. However, those levels are already being reached currently in coastal regions due to natural CO2 variability. Squid are a vital component of the pelagic ecosystem, holding a unique niche as a highly active predatory invertebrate and major prey stock for upper trophic levels. This study examined the effects of a range of ocean acidification regimes on the early life history of a coastal squid species, the Atlantic longfin squid, Doryteuthis pealeii. Eggs were raised in a flow-through ocean acidification system at CO2 levels ranging from ambient (400ppm) to 2200ppm. Time to hatching, hatching efficiency, and hatchling mantle lengths, yolk sac sizes, and statoliths were all examined to elucidate stress effects. Delays in hatching time of at least a day were seen at exposures above 1300ppm in all trials under controlled conditions. Mantle lengths were significantly reduced at exposures above 1300 ppm. Yolk sac sizes varied between CO2 treatments, but no distinct pattern emerged. Statoliths were increasingly porous and malformed as CO2 exposures increased, and were significantly reduced in surface area at exposures above 1300ppm. Doryteuthis pealeii appears to be able to withstand acidosis stress without major effects up to 1300ppm, but is strongly impacted past that threshold. Since yolk consumption did not vary among treatments, it appears that during its early life stages, D. pealeii reallocates its available energy budget away from somatic growth and system development in order to mitigate the stress of acidosis.

  19. Detection and quantification of Vibrio fischeri autoinducer from symbiotic squid light organs.

    Science.gov (United States)

    Boettcher, K J; Ruby, E G

    1995-02-01

    Vibrio fischeri is the specific light organ symbiont of the sepiolid squid species Euprymna scolopes and Euprymna morsei. Both species of squid are luminescent by virtue of their bacterial symbionts, but the natural symbionts of E. scolopes do not produce visible luminescence in laboratory culture. The primary cause of this depressed luminescence by E. scolopes symbionts in culture was found to be the production of relatively low levels of V. fischeri autoinducer, a positive transcriptional coregulator of the lux regulon, identified as N-(3-oxohexanoyl) homoserine lactone. Concentrations of autoinducer activity produced by these symbionts in culture were quantified and found to be at least 10-fold lower than those produced by E. morsei isolates (which are visibly luminous outside the association) and perhaps 10,000-fold lower than those of the brightest V. fischeri strains. Despite the differences in their symbiont strains, the intact light organs of the two species of squid contained comparable amounts of extractable autoinducer activity (between 100 and 200 pg per adult animal). The chromatographic behavior of this autoinducer activity on reverse-phase high-performance liquid chromatography was consistent with its presumptive identification as V. fischeri autoinducer. Within the 5-microliter volume of the epithelial core of the light organ in which the symbiotic V. fischeri strains are housed, these amounts would result in an effective autoinducer concentration of at least 100 nM. Because these levels are over 40-fold higher than the concentration needed for the induction of luminescence of bacteria in culture, we conclude that the inherent degree of autoinducer production by strains of V. fischeri may not influence their effectiveness as light organ symbionts. Furthermore, this study provides the first direct evidence that the phenomenon of cell density-dependent autoinduction, discovered and described first for laboratory cultures of V. fischeri but believed to

  20. Bacterial bioluminescence regulates expression of a host cryptochrome gene in the squid-Vibrio symbiosis.

    Science.gov (United States)

    Heath-Heckman, Elizabeth A C; Peyer, Suzanne M; Whistler, Cheryl A; Apicella, Michael A; Goldman, William E; McFall-Ngai, Margaret J

    2013-04-02

    The symbiosis between the squid Euprymna scolopes and its luminous symbiont, Vibrio fischeri, is characterized by daily transcriptional rhythms in both partners and daily fluctuations in symbiont luminescence. In this study, we sought to determine whether symbionts affect host transcriptional rhythms. We identified two transcripts in host tissues (E. scolopes cry1 [escry1] and escry2) that encode cryptochromes, proteins that influence circadian rhythms in other systems. Both genes cycled daily in the head of the squid, with a pattern similar to that of other animals, in which expression of certain cry genes is entrained by environmental light. In contrast, escry1 expression cycled in the symbiont-colonized light organ with 8-fold upregulation coincident with the rhythms of bacterial luminescence, which are offset from the day/night light regime. Colonization of the juvenile light organ by symbionts was required for induction of escry1 cycling. Further, analysis with a mutant strain defective in light production showed that symbiont luminescence is essential for cycling of escry1; this defect could be complemented by presentation of exogenous blue light. However, blue-light exposure alone did not induce cycling in nonsymbiotic animals, but addition of molecules of the symbiont cell envelope to light-exposed animals did recover significant cycling activity, showing that light acts in synergy with other symbiont features to induce cycling. While symbiont luminescence may be a character specific to rhythms of the squid-vibrio association, resident microbial partners could similarly influence well-documented daily rhythms in other systems, such as the mammalian gut.

  1. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    International Nuclear Information System (INIS)

    Bechstein, S; Petsche, F; Scheiner, M; Drung, D; Thiel, F; Schnabel, A; Schurig, Th

    2006-01-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-T c dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented

  2. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Bechstein, S [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Petsche, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Scheiner, M [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Drung, D [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Thiel, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schnabel, A [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schurig, Th [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

    2006-06-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/{radical}Hz was specially designed for a 304-channel low-T{sub c} dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

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

    Science.gov (United States)

    Yu, Wei; Chen, Xinjun; Yi, Qian

    2017-12-01

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

  4. Development of N-layer materials for SNS junction and SQUID applications

    International Nuclear Information System (INIS)

    Zhou, J.P.; McDevitt, J.T.; Jia, Q.

    1997-01-01

    Materials characteristics including water reactivity, oxygen loss, electromigration of oxide ions, and interfacial reactivity problems have plagued attempts to produce reliable and reproducible cuprate SNS superconductor junctions. In an effort to solve some of these formidable problems, new N-layer compounds from the family of R 1-x Ca x Ba 2-y La y Cu 3-z M z O 7-δ (R = Y, Gd and Pr; M = Co, Ni and Zn; 0 2 Cu 3 O 7-δ phase and the modified materials exhibit enhanced durability properties. The compounds have been utilized to make both SNS junctions and SQUID devices

  5. Magnetic moment oscillation in ammonium perchlorate in a DC SQUID-based magnetic resonance experiment

    International Nuclear Information System (INIS)

    Montero, V.; Cernicchiaro, G.

    2008-01-01

    In this work we describe experimental results in which a DC SQUID (superconducting quantum interference device) is used as free induction decay detector. Measurements of a solid ammonium perchlorate (NH 4 ClO 4 ) sample were performed, in zero field, at 4.2 K. Unexpected magnetic moment oscillations were detected at 1.5 kHz. The computation of the magnetic fields suggests that the proton nuclear magnetic resonance may explain the measured resonance, considering reorientation of the ammonium group by quantum tunneling of protons and a magnetic proton dipole-dipole intermolecular interaction model

  6. Sensory, chemical and bacteriological changes during storage of iced squid ( Todaropsis eblanae )

    DEFF Research Database (Denmark)

    Paarup, T.; Sanchez, J.A.; Moral, A.

    2002-01-01

    Aims: To relate sensory shelf-life of iced whole and gutted squid to bacterial growth and chemical changes. Methods and Results: Cooked mantles from whole and gutted individuals were rejected after 10 and 12 days of storage, respectively, due to ammoniacal off-odours. Rate of production of both...... to spoilage through activity in the digestive gland, followed by diffusion of volatile compounds and amines to the mantle. Significance and Impact of the Study: Due to the psychrophilic nature of P. phosphoreum and Pseudoalteromonas sp., spread- plating and low temperature incubation are recommended...

  7. Study on the Formulation of Squid (Loligosp) Nugget Added with Yellow Pumpkin (Curcubitamoschata) Flour

    OpenAIRE

    Nurharyati, Lisa; ', Suparmi; Sari, N Ira

    2017-01-01

    This study aimed to determine the squid nugget formulation with the addition of pumpkin flour. It was evaluated for the organoleptic value and the proximate composition. The method used was an experimental method and designed as non-factorial completely randomized design (CRD). The treatments were addition of pumpkin flour into the mix, consisting of four levels, namely: N0 (without the addition of pumpkin flour), N1 (pumpkin flour 50 g), N2 (pumpkin flour 75 g) and N3 (pumpkin flour 100 g).B...

  8. Studies of Superfluid 3He Confined to a Regular Submicron Slab Geometry, Using SQUID NMR

    International Nuclear Information System (INIS)

    Casey, Andrew; Corcoles, Antonio; Lusher, Chris; Cowan, Brian; Saunders, John

    2006-01-01

    The effect on the superfluid ground state of confining p-wave superfluid 3He in regular geometries of characteristic size comparable to the diameter of the Cooper pair remains relatively unexplored, in part because of the demands placed by experiments on the sensitivity of the measuring technique. In this paper we report preliminary experiments aimed at the study of 3He confined to a slab geometry. The NMR response of a series of superfluid samples has been investigated using a SQUID NMR amplifier. The sensitivity of this NMR spectrometer enables samples of order 1017 spins, with low filling factor, to be studied with good resolution

  9. Optical extinction of size-controlled aerosols generated from squid chromatophore pigments

    Directory of Open Access Journals (Sweden)

    Sean R. Dinneen

    2017-10-01

    Full Text Available Nanophotonic granules populate the interior of cephalopod chromatophores, contributing to their visible color by selectively absorbing and scattering light. Inspired by the performance of these granules, we fabricated nanostructured aerosols by nebulizing a pigment solution extracted from native squid chromatophores. We determined their optical extinction using cavity ring-down spectroscopy and show how extinction cross section is dependent on both particle concentration and size. This work not only advances the fundamental knowledge of the optical properties of chromatophore pigments but also serves as a proof-of-concept method that can be adapted to develop coatings derived from these pigmentary aerosols.

  10. 洪堡與馬太之對決 Showdown between Humboldt and Matthew

    Directory of Open Access Journals (Sweden)

    張源泉 Yuan-Chuan Chang

    2015-06-01

    has an urgent need for highly educated specialists, higher education has become an emerging industry driving national economic growth. In response to the current situation, Germany has begun making fundamental reforms to its system of higher education. Universities in modern Germany have long subscribed to the ideal of Humboldtian homogeneity. However, in recent years the German government has implemented various measures designed to increase competition, based on the principle that the lion’s share of educational resources should be devoted to those with the most distinguished, the so-called Matthew effect. Framing the current state of higher education in Germany as a showdown between Humboldt and Matthew, in this paper I use document analysis to present the traditional ideal of homogeneity, discuss the measures recently adopted for increasing competition, and to investigate how much influence these measures have had on distinguished students and researchers. Traditionally as the hallmark of the Germany higher education, the Humboldtian model has come into being by the following factors: the legal structure, the regulations preventing the hiring of former students as teaching staff, the non-competitive allocations of funding in higher education, and the way in which the higher education system developed. However, due to such recent measures as the Excellence Initiative, performance-based budget allocations, and the ranking of universities, in recent years German universities have begun to emphasize the importance of differentiation and specialization, while homogeneity has begun to fall by the wayside. While some may see these changes as an actual paradigm shift, due to the continuing influence of the traditional system, as well as the limited effect of the differentiation measures, it is unlikely that the German system of higher education will become as hierarchically structured as ivy-league universities in the United States; instead, it’s more likely that

  11. Development and testing of high temperature-vector-SQUID conductor-magnetometers for the electro-magnetic exploration of our deposits. Final report; SQUID-Anwendungen - Entwicklung und Erprobung von Hochtemperatur-Vektor-Supraleiter SQUID-Magnetometern fuer die elektromagnetische Exploration von Lagerstaetten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Matzander, U.; Friedrichs, B.

    2000-03-01

    Aim of the was the development of a prototype of a 3 axis HTc SQUID magnetometer for the geophysical exploration. The prototype was tested during the project in Germany and in China. Metronix task was the supervision of the development with the direction that the sensor can be used for field measurements and that the manufacturing costs will be acceptable. For magnetotelluric measurements (MT/CSAMT) further development is required to enhance the drift and noise properties of the sensor. The advantages in the geophysical TEM exploration are: greater sounding depth and good conductors (ore bodies) can be penetrated completely; the thickness of the resource can be estimated this way. At the same time the measuring time can be reduced tremendously because of the better signal to noise ratio. The productivity of the measuring campaign increases. If due to further developments coils systems can be replaced in total by the SQUID, SQUID systems will dominate the TEM market. (orig.) [German] Ziel des Projektes war es, einen Prototyp eines 3-achsigen HTc SQUIDS zur Verfuegung zu haben, welcher die Anforderungen fuer geophysikalische Messungen erfuellt. Dieser Prototyp wurde im Laufe des Projektes in Deutschland und China getestet. Die Rolle der Firma Metronix in diesem Projekt war die Einflussnahme auf die Entwicklung in der Form, dass zum einen die aus der Feldmesstechnik resultierenden Anforderungen beruecksichtigt werden, zum anderen auf eine spaetere kostenguenstige Herstellung geachtet wird. Bei magnetotellurischen Messungen (MT/CSAMT) besteht weiterer Bedarf an Verbesserungen hinsichtlich der Drift- und Rauscheigenschaften des Sensors. Fuer die geophysikalische Exploration in der TEM ergeben sich folgende Vorteile: die Erkundungstiefe ist groesser und gute Leiter (Erzkoerper) koennen vollstaendig durchteuft werden; damit kann die Maechtigkeit des Vorkommens bestimmt werden. Gleichzeitig kann auf Grund des besseren Signal / Rauschverhaeltnisses die Messzeit deutlich

  12. Scientific findings of Alexander von Humboldt's expedition into the Spanish-American Tropics (1799-1804 from a geographical point of view

    Directory of Open Access Journals (Sweden)

    Gerd Kohlhepp

    2005-06-01

    Full Text Available Alexander von Humboldt's expedition from 1799 till 1804 to the "equinoctial regions of the new world" led through Venezuela, Cuba, Colombia, Ecuador, Peru, and Mexico. In Europe an increased knowledge of the "New World" was connected with the privately funded journey, which served purely scientific purposes and had nothing to do with the exploration and exploitation of natural resources. Besides the research results, which were based on new measuring methods and the quantitative ascertainment of scientific basics, the journey also made possible detailed descriptions in matters of regional studies including social, socio-economic, political, and economic-geographic circumstances, which were based on empirical field studies. The expedition took place shortly before the political change in Latin America. Humboldt, who still experienced the feudal character of global economy based on slave labor in the colonies, vehemently criticized this economic structure - although he was a noble - and its unbearable social conditions. This is the reason why Humboldt is still admired in Latin America till this day. In Europe the scientific insights of his journey to the tropics and his innovative impulses in geog raphy as well as in many other disciplines brought him fame and lasting recognition as a universal scholar, who had crucial influence on the development of the sciences during the first half of the 19th century.A expedição científica de Alexander von Humboldt de 1799 a 1804 pela região equinocial do novo mundo foi realizada através dos países Venezuela, Cuba, Colômbia, Equador, Peru e México. Esta viagem, destinada à obtenção de novos conhecimentos aprofundados sobre o "novo mundo" para a Europa, foi financiada com meios particulares e tinha exclusivamente objetivos científicos e não a exploração de recursos naturais. Paralelamente aos resultados de pesquisa, fundamentados em novos métodos de medida e da elaboração quantitativa de

  13. SQUID measurements of remanent magnetisation in refillable 3He spin-filter cells (SFC)

    Science.gov (United States)

    Hutanu, V.; Rupp, A.; Sander-Thömmes, T.

    2007-07-01

    A strong influence of external magnetic fields on the relaxation time constant T1 of glass cells serving as reservoirs for polarised 3He, observed for various alkali metal-coated cells made of different glass types, was initially associated with the presence of a large number of ferromagnetic clusters on the glass surface. Later experiments showed the presence of the so-called “ T1 hysteresis” phenomenon with a similar distinctiveness also in uncoated cells made of pure synthetic quartz glass. It suggests that the origin of such a relaxation is a macroscopic magnetisation in the bulk of the cell. We present the results of a multi-SQUID system investigation on magnetised and non-magnetised quartz glass cells, Cs coated as well as bare wall, to be used as neutron spin filters at HMI Berlin. The presence of a macroscopic remanent magnetic moment in the cells after their exposition to external magnetic fields has been experimentally shown. More than 80% of the remanent magnetic moment of the magnetised cells was found to be concentrated in the region of the glass valves. SQUID measurements reveal the existence of some remanent magnetisation in all valve parts and also in the vacuum grease, but most magnetic are the plastic parts and the O-ring. Different valve and sealing types have been compared in order to find the less magnetisable one.

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

    Science.gov (United States)

    Packard, Andrew

    2011-03-01

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

  15. Effects of cholinergic compounds on the axon-Schwann cell relationship in the squid nerve fiber.

    Science.gov (United States)

    Villegas, J

    1975-04-01

    The effects of acetylcholine, carbamylcholine, D-tubocurarine, eserine, and alpha-bungarotoxin on the Schwann cell electrical potential of resting and stimulated squid nerve fibers were studied. Acetylcholine (10-7 M) and barbamylcholine (10-6 M) induce a prolonged hyper polarization in the Schwann cells of the unstimulated nerve fiber. In the presence of carbamylcholine (10-6 M) the behavior of the Schwann cell membrane to changes in the external potassium concentration approximates the behavior of an ideal potassium electrode. D-Tubocurarine (10-9 M) blocks the hyperpolarizing effects of nerve impulse trains and carbamylcholine (10-6 M), whereas at the same concentration eserine prolongs the Schwann cell hyperpolarizations induced by axon stimulation or by acetylcholine (10-7 M). alpha-Bungarotoxin (10-9M) also blocks the hyperpolarizing effect of nerve impulse trains and of carbamylcholine. D-Tubocurarine (10-5M) protects the Schwann cells against the irreversible action of alpha-bungarotoxin. These results show the existence of acetylcholine receptors in the Schwann cell membrane. Preliminary measurements of the binding of 125I-alpha bungarotoxin to the plasma membranes isolated from squid nerves also indicate the presence of acetylcholine receptors. These findings support the involvement of cholinergic mechanisms in the axon-Schwann cell relationship previously described.

  16. Mapping of Ambient Magnetic Fields within Liquid Helium Dewar for Testing of a DC SQUID Magnetometer

    International Nuclear Information System (INIS)

    Newhouse, Randal

    2003-01-01

    In an effort to explore the cavity lights phenomenon, Experimental Facilities Department at SLAC is testing a DC SQUID magnetometer. Due to the nature of the SQUID magnetometer and the intended tests, the earth's magnetic field must be negated. It is proposed to reduce ambient fields using bucking coils. First, however, an accurate map of the magnetic field inside the liquid helium Dewar where the experiment is going to take place needed to be made. This map was made using a three-axis fluxgate magnetometer mounted on a 3D positioning device made for this purpose. A ten inch tall volume within the Dewar was measured at data points approximately an inch from each other in all three axes. A LabVEIW program took readings from the magnetometer at 2 ms intervals for 1000 readings in such a way as to eliminate any ambient 60 Hz signals that may be present in the data. This data was stored in spreadsheet format and was analyzed to determine how the magnetic field within the Dewar was changing as a function of position

  17. Ocean acidification responses in paralarval squid swimming behavior using a novel 3D tracking system

    KAUST Repository

    Zakroff, Casey J.

    2017-08-22

    Chronic embryonic exposure to ocean acidification (OA) has been shown to degrade the aragonitic statolith of paralarval squid, Doryteuthis pealeii, a key structure for their swimming behavior. This study examined if day-of-hatching paralarval D. pealeii from eggs reared under chronic OA demonstrated measurable impairments to swimming activity and control. This required the development of a novel, cost-effective, and robust method for 3D motion tracking and analysis. Squid eggs were reared in pCO2 levels in a dose-dependent manner ranging from 400 to 2200 ppm. Initial 2D experiments showed paralarvae in higher acidification environments spent more time at depth. In 3D experiments, velocity, particularly positive and negative vertical velocities, significantly decreased from 400 to 1000 ppm pCO2, but showed non-significant decreases at higher concentrations. Activity and horizontal velocity decreased linearly with increasing pCO2, indicating a subtle impact to paralarval energetics. Patterns may have been obscured by notable individual variability in the paralarvae. Responses were also seen to vary between trials on cohort or potentially annual scales. Overall, paralarval swimming appeared resilient to OA, with effects being slight. The newly developed 3D tracking system provides a powerful and accessible method for future studies to explore similar questions in the larvae of aquatic taxa.

  18. High critical current density YBCO films and fabrication of dc-SQUIDs

    CERN Document Server

    Kuriki, S; Kawaguchi, Y; Matsuda, M; Otowa, T

    2002-01-01

    In order to improve the sensitivity of SQUID magnetometers made of high-T sub c films, we have studied the conditions of pulsed-laser deposition of YBCO films. Among the different deposition parameters examined, extensive degassing of the vacuum chamber before and precise control of the substrate temperature during the film deposition were found effective for obtaining high critical temperature T sub c and high critical current density J sub c. It was also found that the residual-resistance ratio has a clear correlation with J sub c , indicating that it can be a good, and easy to measure, index of the film quality. Films having T sub c approx 89-90 K and J sub c >= 5x10 sup 6 A cm sup - sup 2 at 77 K were used to fabricate SQUIDs without a pickup loop. Grain-boundary junctions formed on bicrystal substrates with a 30 deg. misorientation angle exhibited I sub c R sub n values of more than 100 mu V at 77 K. The well-known scaling behaviour of the relation I sub c R sub n propor to (J sup G sup B sub c) sup 1 su...

  19. Squid-inspired vehicle design using coupled fluid-solid analytical modeling

    Science.gov (United States)

    Giorgio-Serchi, Francesco; Weymouth, Gabriel

    2017-11-01

    The need for enhanced automation in the marine and maritime fields is fostering research into robust and highly maneuverable autonomous underwater vehicles. To address these needs we develop design principles for a new generation of soft-bodied aquatic vehicles similar to octopi and squids. In particular, we consider the capability of pulsed-jetting bodies to boost thrust by actively modifying their external body-shape and in this way benefit of the contribution from added-mass variation. We present an analytical formulation of the coupled fluid-structure interaction between the elastic body and the ambient fluid. The model incorporates a number of new salient contributions to the soft-body dynamics. We highlight the role of added-mass variation effects of the external fluid in enhancing thrust and assess how the shape-changing actuation is impeded by a confinement-related unsteady inertial term and by an external shape-dependent fluid stiffness contribution. We show how the analysis of these combined terms has guided us to the design of a new prototype of a squid-inspired vehicle tuning of the natural frequency of the coupled fluid-solid system with the purpose of optimizing its actuation routine.

  20. Nondestructive evaluation of braided carbon fiber composites with artificial defect using HTS-SQUID gradiometer

    International Nuclear Information System (INIS)

    Shinyama, Y.; Yamaji, T.; Hatsukade, Y.; Takai, Y.; Aly-Hassan, M.S.; Nakai, A.; Hamada, H.; Tanaka, S.

    2011-01-01

    We applied a current-injection-based NDE method using a HTS-SQUID gradiometer to a braided CFRP with artificial cracks. Current distributions in the braided CFRP were estimated from measured field gradient distributions. A small crack, in which a few carbon-fiber bundles were cut, was well detected from the current distributions. A cross-section of the CFRP showed that a density of the bundles at edges is higher than the other part. The experimental results demonstrated the capability of the method to detect sub-mm cracks. Braided carbon fiber reinforced plastics (CFRPs) are one of multifunctional materials with superior properties such as mechanical strength to normal CFRPs since the braided CFRPs have continuous fiber bundles. In this paper, we applied the current-injection-based nondestructive evaluation (NDE) method using a HTS-SQUID gradiometer to the braided CFRP for the detection of the breakage of the bundles. We prepared planar braided CFRP samples with and without artificial cracks of 1 and 2 mm lengths, and measured the current density distribution above the samples using the NDE method. In the measurement results, not only a few completely-cut bundles but also the additional partially-cut bundles were detected from decrease in the measured current density along the cut bundle around the cracks. From these results, we showed that it is possible to inspect a few partially-cut bundles in the braided CFRPs by the NDE method.