WorldWideScience

Sample records for easy-to-use squid sensors

  1. SQUID position sensor development

    Science.gov (United States)

    Torii, Rodney

    1996-11-01

    I describe the development of an inductance position sensor for the STEP (satellite test of the equivalence principle) accelerometer. I have measured the inductance (with an experimental error of 0.5%) of a single-turn thin-film niobium pick-up coil as a function of the distance from a thin-film niobium disc (both at 4.2 K and superconducting). The circular pick-up coil had a diameter of 4 cm with a track width of 0264-9381/13/11A/022/img1. The disc (mock test mass) had a diameter of 4 cm. The distance range between the coil and disc was set by the range of a low-temperature differential capacitance sensor: 0 - 2 mm with a resolution of 0264-9381/13/11A/022/img2. The full range of the low-temperature translation stage was 0 - 4 mm. The inductance was measured using an LCR meter in a four-wire configuration. The measured inductance was compared to the inductance of a circular loop above a superconducting plane. Due to the fact that the thin-film disc is of finite size, the calculation differed from experiment by as much as 12%. I have also calculated the inductance by segmenting the thin-film niobium disc into 500 concentric rings (each with a width of 0264-9381/13/11A/022/img3). A discrepancy between calculation and experiment of approximately 3% was found.

  2. 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

  3. 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.

  4. Easy-to-use interface

    International Nuclear Information System (INIS)

    Blattner, D O; Blattner, M M; Tong, Y.

    1999-01-01

    Easy-to-use interfaces are a class of interfaces that fall between public access interfaces and graphical user interfaces in usability and cognitive difficulty. We describe characteristics of easy-to-use interfaces by the properties of four dimensions: selection, navigation, direct manipulation, and contextual metaphors. Another constraint we introduced was to include as little text as possible, and what text we have will be in at least four languages. Formative evaluations were conducted to identify and isolate these characteristics. Our application is a visual interface for a home automation system intended for a diverse set of users. The design will be expanded to accommodate the visually disabled in the near future

  5. 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.

  6. 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

  7. 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.

  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. 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)

  10. 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)

  11. 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.

  12. 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

  13. An easy-to-use diagnostic system development shell

    Science.gov (United States)

    Tsai, L. C.; Ross, J. B.; Han, C. Y.; Wee, W. G.

    1987-01-01

    The Diagnostic System Development Shell (DSDS), an expert system development shell for diagnostic systems, is described. The major objective of building the DSDS is to create a very easy to use and friendly environment for knowledge engineers and end-users. The DSDS is written in OPS5 and CommonLisp. It runs on a VAX/VMS system. A set of domain independent, generalized rules is built in the DSDS, so the users need not be concerned about building the rules. The facts are explicitly represented in a unified format. A powerful check facility which helps the user to check the errors in the created knowledge bases is provided. A judgement facility and other useful facilities are also available. A diagnostic system based on the DSDS system is question driven and can call or be called by other knowledge based systems written in OPS5 and CommonLisp. A prototype diagnostic system for diagnosing a Philips constant potential X-ray system has been built using the DSDS.

  14. SQUID: sensorized shirt with smartphone interface for exercise monitoring and home rehabilitation.

    Science.gov (United States)

    Farjadian, Amir B; Sivak, Mark L; Mavroidis, Constantinos

    2013-06-01

    Stroke is a leading cause of serious long-term disability in the United States. There is a need for new technological adjuncts to expedite patients' scheduled discharge from hospital and pursue rehabilitation procedure at home. SQUID is a low-cost, smart shirt that incorporates a six-channel electromyography (EMG) and heart rate data acquisition module to deliver objective audiovisual and haptic biofeedback to the patient. The sensorized shirt is interfaced with a smartphone application, for the subject's usage at home, as well as the online database, for the therapist's remote supervision from hospital. A single healthy subject was recruited to investigate the system functionality during improperly performed exercise. The system can potentially be used in automated, remote monitoring of variety of physical therapy exercises, rooted in strength or coordination training of specific muscle groups.

  15. 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)

  16. Easy-to-Use UAV Ground Station Software for Low-Altitude Civil Operations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design and develop easy-to-use Ground Control Station (GCS) software for low-altitude civil Unmanned Aerial Vehicle (UAV) operations. The GCS software...

  17. Quebec Trophoblastic Disease Registry: how to make an easy-to-use dynamic database.

    Science.gov (United States)

    Sauthier, Philippe; Breguet, Magali; Rozenholc, Alexandre; Sauthier, Michaël

    2015-05-01

    To create an easy-to-use dynamic database designed specifically for the Quebec Trophoblastic Disease Registry (RMTQ). It is now well established that much of the success in managing trophoblastic diseases comes from the development of national and regional reference centers. Computerized databases allow the optimal use of data stored in these centers. We have created an electronic data registration system by producing a database using FileMaker Pro 12. It uses 11 external tables associated with a unique identification number for each patient. Each table allows specific data to be recorded, incorporating demographics, diagnosis, automated staging, laboratory values, pathological diagnosis, and imaging parameters. From January 1, 2009, to December 31, 2013, we used our database to register 311 patients with 380 diseases and have seen a 39.2% increase in registrations each year between 2009 and 2012. This database allows the automatic generation of semilogarithmic curves, which take into account β-hCG values as a function of time, complete with graphic markers for applied treatments (chemotherapy, radiotherapy, or surgery). It generates a summary sheet for a synthetic vision in real time. We have created, at a low cost, an easy-to-use database specific to trophoblastic diseases that dynamically integrates staging and monitoring. We propose a 10-step procedure for a successful trophoblastic database. It improves patient care, research, and education on trophoblastic diseases in Quebec and leads to an opportunity for collaboration on a national Canadian registry.

  18. esATAC: An Easy-to-use Systematic pipeline for ATAC-seq data analysis.

    Science.gov (United States)

    Wei, Zheng; Zhang, Wei; Fang, Huan; Li, Yanda; Wang, Xiaowo

    2018-03-07

    ATAC-seq is rapidly emerging as one of the major experimental approaches to probe chromatin accessibility genome-wide. Here, we present "esATAC", a highly integrated easy-to-use R/Bioconductor package, for systematic ATAC-seq data analysis. It covers essential steps for full analyzing procedure, including raw data processing, quality control and downstream statistical analysis such as peak calling, enrichment analysis and transcription factor footprinting. esATAC supports one command line execution for preset pipelines, and provides flexible interfaces for building customized pipelines. esATAC package is open source under the GPL-3.0 license. It is implemented in R and C ++. Source code and binaries for Linux, MAC OS X and Windows are available through Bioconductor https://www.bioconductor.org/packages/release/bioc/html/esATAC.html). xwwang@tsinghua.edu.cn. Supplementary data are available at Bioinformatics online.

  19. Motofit - integrating neutron reflectometry acquisition, reduction and analysis into one, easy to use, package

    International Nuclear Information System (INIS)

    Nelson, Andrew

    2010-01-01

    The efficient use of complex neutron scattering instruments is often hindered by the complex nature of their operating software. This complexity exists at each experimental step: data acquisition, reduction and analysis, with each step being as important as the previous. For example, whilst command line interfaces are powerful at automated acquisition they often reduce accessibility by novice users and sometimes reduce the efficiency for advanced users. One solution to this is the development of a graphical user interface which allows the user to operate the instrument by a simple and intuitive 'push button' approach. This approach was taken by the Motofit software package for analysis of multiple contrast reflectometry data. Here we describe the extension of this package to cover the data acquisition and reduction steps for the Platypus time-of-flight neutron reflectometer. Consequently, the complete operation of an instrument is integrated into a single, easy to use, program, leading to efficient instrument usage.

  20. Comparison of concepts in easy-to-use methods for MSD risk assessment.

    Science.gov (United States)

    Roman-Liu, Danuta

    2014-05-01

    This article presents a comparative analysis of easy-to-use methods for assessing musculoskeletal load and the risk for developing musculoskeletal disorders. In all such methods, assessment of load consists in defining input data, the procedure and the system of assessment. This article shows what assessment steps the methods have in common; it also shows how those methods differ in each step. In addition, the methods are grouped according to their characteristic features. The conclusion is that the concepts of assessing risk in different methods can be used to develop solutions leading to a comprehensive method appropriate for all work tasks and all parts of the body. However, studies are necessary to verify the accepted premises and to introduce some standardization that would make consolidation possible. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  1. 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.

  2. E/Z MAS: An easy-to-use computerized materials control and accountability system

    International Nuclear Information System (INIS)

    Anderson, L.K.; Boor, M.G.; Hurford, J.M.; Landry, R.P.; Martinez, B.J.; Solem, A.M.; Whiteson, R.; Zardecki, A.

    1998-01-01

    Nuclear facilities that handle and process nuclear materials are required to track their nuclear holdings and to keep adequate records that manage and control the inventory of those holdings. The complexity of a system that does this job is directly proportional to the complexity of the facility's operations. This paper describes an approach to computerized materials protection, control, and accountability (MPC and A) that was introduced by Los Alamos National Laboratory (LANL) in the fall of 1997. This new system, E/Z MAS, is the latest addition to the LANL suite of computerized MPC and A tools, which also includes the CoreMAS system. E/Z MAS was initially designed to address the needs of those facilities that have small to modest MPC and A needs but has been expanded to provide full functionality for any facility. The system name, E/Z MAS, reflects the system's easy-to-use characteristics, which include ease of installation and ease of software maintenance. Both CoreMAS and E/Z MAS have been provided to facilities in the Former Soviet Union to assist them in implementing a computerized MPC and A system that meets their needs. In this paper the authors will address the functionality of CoreMAS and E/Z MAS, and an argument in favor of intranet-based material control and accountability will be advanced

  3. Development of an Easy-to-Use Tool for the Assessment of Emergency Department Physical Design

    Directory of Open Access Journals (Sweden)

    Alireza Majidi

    2014-03-01

    Full Text Available Physical design of the emergency department (ED has an important effect on its role and function. To date, no guidelines have been introduced to set the standards for the construction of EDs in Iran. In this study we aim to devise an easy-to-use tool based on the available literature and expert opinion for the quick and effective assessment of EDs in regards to their physical design. For this purpose, based on current literature on emergency design, a comprehensive checklist was developed.  Then, this checklist was analyzed by a panel consisting of heads of three major EDs and contradicting items were decided. Overall 178 crude items were derived from available literature. The Items were categorized in to three major domains of Physical space, Equipment, and Accessibility. The final checklist approved by the panel consisted of 163 items categorized into six domains. Each item was phrased as a “Yes or No” question for ease of analysis, meaning that the criterion is either met or not. 

  4. Helping technophobic teachers ease the burden of marking with easy-to-use online quizzes

    Directory of Open Access Journals (Sweden)

    LIP Paul Chi Hong

    2008-12-01

    Full Text Available A number of studies have shown that teacher stress was due to teachers spending long hours in marking their students’ work such as quizzes and examination papers from large class sizes. With this problem in mind, a new web 2.0 technology has emerged, Quiz Center supported by DiscoverySchool.com which can help technophobic teachers make a free and easy-to-use online quiz. Online quizzes can be automatically marked by a script or managed by a server. In this paper, the following sections were addressed:1 the need for using online quizzes to ease the burden of teachers:2 the definitions of different types of online quizzes and the advantages and reasons for using them;3 the reasons for using Quiz Center from DiscoverySchool.com; 4 a sharing of how I made an online multiple-choice email quiz with Quiz Center from the perspective of a technophobic teacher; and 5 a discussion on the limitations, recommendations and implications for using online quizzes.

  5. Easy-to-use augmented reality neuronavigation using a wireless tablet PC.

    Science.gov (United States)

    Deng, Weiwei; Li, Fang; Wang, Manning; Song, Zhijian

    2014-01-01

    Augmented reality (AR) technology solves the problem of view switching in traditional image-guided neurosurgery systems by integrating computer-generated objects into the actual scene. However, the state-of-the-art AR solution using head-mounted displays has not been widely accepted in clinical applications because it causes some inconvenience for the surgeon during surgery. In this paper, we present a Tablet-AR system that transmits navigation information to a movable tablet PC via a wireless local area network and overlays this information on the tablet screen, which simultaneously displays the actual scene captured by its back-facing camera. With this system, the surgeon can directly observe the intracranial anatomical structure of the patient with the overlaid virtual projection images to guide the surgery. The alignment errors in the skull specimen study and clinical experiment were 4.6 pixels (approx. 1.6 mm) and 6 pixels (approx. 2.1 mm), respectively. The system was also used for navigation in 2 actual clinical cases of neurosurgery, which demonstrated its feasibility in a clinical application. The easy-to-use Tablet-AR system presented in this study is accurate and feasible in clinical applications and has the potential to become a routine device in AR neuronavigation.

  6. An Easy-to-Use Airborne LiDAR Data Filtering Method Based on Cloth Simulation

    Directory of Open Access Journals (Sweden)

    Wuming Zhang

    2016-06-01

    Full Text Available Separating point clouds into ground and non-ground measurements is an essential step to generate digital terrain models (DTMs from airborne LiDAR (light detection and ranging data. However, most filtering algorithms need to carefully set up a number of complicated parameters to achieve high accuracy. In this paper, we present a new filtering method which only needs a few easy-to-set integer and Boolean parameters. Within the proposed approach, a LiDAR point cloud is inverted, and then a rigid cloth is used to cover the inverted surface. By analyzing the interactions between the cloth nodes and the corresponding LiDAR points, the locations of the cloth nodes can be determined to generate an approximation of the ground surface. Finally, the ground points can be extracted from the LiDAR point cloud by comparing the original LiDAR points and the generated surface. Benchmark datasets provided by ISPRS (International Society for Photogrammetry and Remote Sensing working Group III/3 are used to validate the proposed filtering method, and the experimental results yield an average total error of 4.58%, which is comparable with most of the state-of-the-art filtering algorithms. The proposed easy-to-use filtering method may help the users without much experience to use LiDAR data and related technology in their own applications more easily.

  7. SSTAR, a Stand-Alone Easy-To-Use Antimicrobial Resistance Gene Predictor.

    Science.gov (United States)

    de Man, Tom J B; Limbago, Brandi M

    2016-01-01

    We present the easy-to-use Sequence Search Tool for Antimicrobial Resistance, SSTAR. It combines a locally executed BLASTN search against a customizable database with an intuitive graphical user interface for identifying antimicrobial resistance (AR) genes from genomic data. Although the database is initially populated from a public repository of acquired resistance determinants (i.e., ARG-ANNOT), it can be customized for particular pathogen groups and resistance mechanisms. For instance, outer membrane porin sequences associated with carbapenem resistance phenotypes can be added, and known intrinsic mechanisms can be included. Unique about this tool is the ability to easily detect putative new alleles and truncated versions of existing AR genes. Variants and potential new alleles are brought to the attention of the user for further investigation. For instance, SSTAR is able to identify modified or truncated versions of porins, which may be of great importance in carbapenemase-negative carbapenem-resistant Enterobacteriaceae. SSTAR is written in Java and is therefore platform independent and compatible with both Windows and Unix operating systems. SSTAR and its manual, which includes a simple installation guide, are freely available from https://github.com/tomdeman-bio/Sequence-Search-Tool-for-Antimicrobial-Resistance-SSTAR-. IMPORTANCE Whole-genome sequencing (WGS) is quickly becoming a routine method for identifying genes associated with antimicrobial resistance (AR). However, for many microbiologists, the use and analysis of WGS data present a substantial challenge. We developed SSTAR, software with a graphical user interface that enables the identification of known AR genes from WGS and has the unique capacity to easily detect new variants of known AR genes, including truncated protein variants. Current software solutions do not notify the user when genes are truncated and, therefore, likely nonfunctional, which makes phenotype predictions less accurate. SSTAR

  8. Development of sensorless easy-to-use overhead crane system via simulation based control

    Science.gov (United States)

    Tagawa, Yasutaka; Mori, Yoshihito; Wada, Masaomi; Kawajiri, Eisaku; Nouzuka, Kazuma

    2016-09-01

    This paper describes the newly developed overhead crane which has a sensorless vibration control system. Generally, loads which are carried by the overhead cranes are easy to vibrate and only skilled people can operate the cranes. Therefore, a lot of studies have been done to solve this problem by using feedback control with vibration sensors. However vibration sensors often break down in severe industrial environment and more reliable control systems are required. For this reason, we have been developing sensorless control system for overhead cranes. In this paper, we firstly introduce basic idea of simulation based control which is called IDCS, then overview and modeling of the overhead crane is presented. Next, the control system design of the overhead crane is discussed, and experimental results are shown for real overhead crane with 2 axes.

  9. Low noise SQUIDs

    Science.gov (United States)

    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.

  10. 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.

  11. An easy-to-use semiquantitative food record validated for energy intake by using doubly labelled water technique.

    Science.gov (United States)

    Koebnick, C; Wagner, K; Thielecke, F; Dieter, G; Höhne, A; Franke, A; Garcia, A L; Meyer, H; Hoffmann, I; Leitzmann, P; Trippo, U; Zunft, H J F

    2005-09-01

    Estimating dietary intake is important for both epidemiological and clinical studies, but often lacks accuracy. To investigate the accuracy and validity of energy intake estimated by an easy-to-use semiquantitative food record (EI(SQFR)) compared to total energy expenditure (TEE) estimated by doubly labelled water technique (EE(DLW)). TEE was measured in 29 nonobese subjects using the doubly labelled water method over a period of 14 days. Within this period, subjects reported their food consumption by a newly developed semiquantitative food record for 4 consecutive days. Energy intake was calculated using the German Food Code and Nutrition Data Base BLS II.3. A good correlation was observed between EI(SQFR) and EE(DLW) (r = 0.685, P 20% in nine subjects (31%). In five subjects (17%), an overestimation of EI(SQFR) was observed. The easy-to-use semiquantitative food record provided good estimates of EI in free-living and nonobese adults without prior detailed verbal instructions. The presented food record has limitations regarding accuracy at the individual level.

  12. 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.)

  13. PANDA-view: An easy-to-use tool for statistical analysis and visualization of quantitative proteomics data.

    Science.gov (United States)

    Chang, Cheng; Xu, Kaikun; Guo, Chaoping; Wang, Jinxia; Yan, Qi; Zhang, Jian; He, Fuchu; Zhu, Yunping

    2018-05-22

    Compared with the numerous software tools developed for identification and quantification of -omics data, there remains a lack of suitable tools for both downstream analysis and data visualization. To help researchers better understand the biological meanings in their -omics data, we present an easy-to-use tool, named PANDA-view, for both statistical analysis and visualization of quantitative proteomics data and other -omics data. PANDA-view contains various kinds of analysis methods such as normalization, missing value imputation, statistical tests, clustering and principal component analysis, as well as the most commonly-used data visualization methods including an interactive volcano plot. Additionally, it provides user-friendly interfaces for protein-peptide-spectrum representation of the quantitative proteomics data. PANDA-view is freely available at https://sourceforge.net/projects/panda-view/. 1987ccpacer@163.com and zhuyunping@gmail.com. Supplementary data are available at Bioinformatics online.

  14. X-ray beam-position feedback system with easy-to-use beam-position monitor.

    Science.gov (United States)

    Park, Jae Yeon; Kim, Yesul; Lee, Sangsul; Lim, Jun

    2018-05-01

    X-ray beam-position stability is indispensable in cutting-edge experiments using synchrotron radiation. Here, for the first time, a beam-position feedback system is presented that utilizes an easy-to-use X-ray beam-position monitor incorporating a diamond-fluorescence screen. The acceptable range of the monitor is above 500 µm and the feedback system maintains the beam position within 3 µm. In addition to being inexpensive, the system has two key advantages: it works without a scale factor for position calibration, and it has no dependence on X-ray energy, X-ray intensity, beam size or beam shape.

  15. Can easy-to-use software deliver effective e-learning in dental education? A randomised controlled study.

    Science.gov (United States)

    Woelber, J P; Hilbert, T S; Ratka-Krüger, P

    2012-08-01

    For the production of computer-based learning environments, a wide range of software solutions can be used which differ not only in their functionality but also vary in cost and ease to program. The aim of our study was to evaluate the overall efficiency and student's perception of two case-based e-learning programs that were produced with either an easy-to-use or a complex software. Eighty-five dental students were randomly assigned to one of two experimental groups. One group studied with a laborious, high-interactive e-learning program (complex-software group). The second group studied within a low-interactive learning environment (easy-software group) that was easy to be programmed. Both programs identically referred to a case report on localised aggressive periodontitis. Learning outcome was tested by a pre- and post-test. Furthermore, questionnaires on workload, motivation, perceived usefulness and perceived learning outcome were used. Learners in the easy-software group showed better results in the post-test F(1, 82) = 4.173, P software tools have the potential to be beneficial in dental education. Students were showing a high acceptance and ability in using both e-learning environments. We conclude that e-learning programs for case-based learning do not have to be overly laborious to program to be useful. Based on our results, we want to encourage instructors to produce case-based e-learning tools with easy-to-use software. © 2012 John Wiley & Sons A/S.

  16. Construction of an easy-to-use CRISPR-Cas9 system by patching a newly designed EXIT circuit.

    Science.gov (United States)

    Tang, Qiang; Lou, Chunbo; Liu, Shuang-Jiang

    2017-01-01

    Plasmid-borne genetic editing tools, including the widely used CRISPR-Cas9 system, have greatly facilitated bacterial programming to obtain novel functionalities. However, the lack of effective post-editing plasmid elimination methods impedes follow-up genetic manipulation or application. Conventional strategies including exposure to physical and chemical treatments, or exploiting temperature-sensitive replication origins have several drawbacks (e.g., they are limited for efficiency and are time-consuming). Therefore, the demand is apparent for easy and rapid elimination of the tool plasmids from their bacterial hosts after genetic manipulation. To bridge this gap, we designed a novel EXIT circuit with the homing endonuclease, which can be exploited for rapid and efficient elimination of various plasmids with diverse replication origins. As a proof of concept, we validated the EXIT circuit in Escherichia coli by harnessing homing endonuclease I- Sce I and its cleavage site. When integrated into multiple plasmids with different origins, the EXIT circuit allowed them to be eliminated from the host cells, simultaneously. By combining the widely used plasmid-borne CRISPR-Cas9 system and the EXIT circuit, we constructed an easy-to-use CRISPR-Cas9 system that eliminated the Cas9- and the single-guide RNA (sgRNA)-encoding plasmids in one-step. Within 3 days, we successfully constructed an atrazine-degrading E. coli strain, thus further demonstrating the advantage of this new CRISPR-Cas9 system for bacterial genome editing. Our novel EXIT circuit, which exploits the homing endonuclease I- Sce I, enables plasmid(s) with different replication origins to be eliminated from their host cells rapidly and efficiently. We also developed an easy-to-use CRISPR-Cas9 system with the EXIT circuit, and this new system can be widely applied to bacterial genome editing.

  17. 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.

  18. 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

  19. 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....

  20. 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...

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.)

  17. 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

  18. 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.

  19. Toward a holistic environmental impact assessment of marble quarrying and processing: proposal of a novel easy-to-use IPAT-based method.

    Science.gov (United States)

    Capitano, Cinzia; Peri, Giorgia; Rizzo, Gianfranco; Ferrante, Patrizia

    2017-03-01

    Marble is a natural dimension stone that is widely used in building due to its resistance and esthetic qualities. Unfortunately, some concerns have arisen regarding its production process because quarrying and processing activities demand significant amounts of energy and greatly affect the environment. Further, performing an environmental analysis of a production process such as that of marble requires the consideration of many environmental aspects (e.g., noise, vibrations, dust and waste production, energy consumption). Unfortunately, the current impact accounting tools do not seem to be capable of considering all of the major aspects of the (marble) production process that may affect the environment and thus cannot provide a comprehensive and concise assessment of all environmental aspects associated with the marble production process. Therefore, innovative, easy, and reliable methods for evaluating its environmental impact are necessary, and they must be accessible for the non-technician. The present study intends to provide a contribution in this sense by proposing a reliable and easy-to-use evaluation method to assess the significance of the environmental impacts associated with the marble production process. In addition, an application of the method to an actual marble-producing company is presented to demonstrate its practicability. Because of its relative ease of use, the method presented here can also be used as a "self-assessment" tool for pursuing a virtuous environmental policy because it enables company owners to easily identify the segments of their production chain that most require environmental enhancement.

  20. NANODEVICE: Novel Concepts, Methods, and Technologies for the Production of Portable, Easy-to-use Devices for the Measurement and Analysis of Airborne Engineered Nanoparticles in Workplace Air

    Energy Technology Data Exchange (ETDEWEB)

    Sirvioe, Sari; Savolainen, Kai, E-mail: sari.sirvio@ttl.fi [Finnish Institute of Occupational Health, Topeliuksenkatu 41 a A, 00250, Helsinki (Finland)

    2011-07-06

    NANODEVICE is a research project funded by the European Commission in the context of the 7th Framework Programme. The duration is 48 months starting 1st of April 2009. Due to their unique properties, engineered nanoparticles (ENP) are now used for a myriad of novel applications, and have a great economic and technological importance. However, some of these properties, especially their surface reactivity, have raised health concerns due to their potential health effects. There is currently a shortage of field-worthy, cost-effective ways - especially in real time - for reliable assessment of exposure levels to ENP in workplace air. NANODEVICE will provide new information on the physico-chemical properties of engineered nanoparticles (ENP) and information about their toxicology. The main emphasis of the project is in the development of novel measuring devices to assess the exposure to ENP's from workplace air. The purpose of the project is also to promote the safe use of ENP through guidance, standards and education, implementing of safety objectives in ENP production and handling, and promotion of safety related collaborations through an international nanosafety forum. The main project goal is to develop innovative concepts and reliable methods for characterizing ENP in workplace air with novel, portable and easy-to-use devices suitable for workplaces.

  1. NANODEVICE: Novel Concepts, Methods, and Technologies for the Production of Portable, Easy-to-use Devices for the Measurement and Analysis of Airborne Engineered Nanoparticles in Workplace Air

    Science.gov (United States)

    Sirviö, Sari; Savolainen, Kai

    2011-07-01

    NANODEVICE is a research project funded by the European Commission in the context of the 7th Framework Programme. The duration is 48 months starting 1st of April 2009. Due to their unique properties, engineered nanoparticles (ENP) are now used for a myriad of novel applications, and have a great economic and technological importance. However, some of these properties, especially their surface reactivity, have raised health concerns due to their potential health effects. There is currently a shortage of field-worthy, cost-effective ways - especially in real time - for reliable assessment of exposure levels to ENP in workplace air. NANODEVICE will provide new information on the physico-chemical properties of engineered nanoparticles (ENP) and information about their toxicology. The main emphasis of the project is in the development of novel measuring devices to assess the exposure to ENP's from workplace air. The purpose of the project is also to promote the safe use of ENP through guidance, standards and education, implementing of safety objectives in ENP production and handling, and promotion of safety related collaborations through an international nanosafety forum. The main project goal is to develop innovative concepts and reliable methods for characterizing ENP in workplace air with novel, portable and easy-to-use devices suitable for workplaces.

  2. NANODEVICE: Novel Concepts, Methods, and Technologies for the Production of Portable, Easy-to-use Devices for the Measurement and Analysis of Airborne Engineered Nanoparticles in Workplace Air

    International Nuclear Information System (INIS)

    Sirvioe, Sari; Savolainen, Kai

    2011-01-01

    NANODEVICE is a research project funded by the European Commission in the context of the 7th Framework Programme. The duration is 48 months starting 1st of April 2009. Due to their unique properties, engineered nanoparticles (ENP) are now used for a myriad of novel applications, and have a great economic and technological importance. However, some of these properties, especially their surface reactivity, have raised health concerns due to their potential health effects. There is currently a shortage of field-worthy, cost-effective ways - especially in real time - for reliable assessment of exposure levels to ENP in workplace air. NANODEVICE will provide new information on the physico-chemical properties of engineered nanoparticles (ENP) and information about their toxicology. The main emphasis of the project is in the development of novel measuring devices to assess the exposure to ENP's from workplace air. The purpose of the project is also to promote the safe use of ENP through guidance, standards and education, implementing of safety objectives in ENP production and handling, and promotion of safety related collaborations through an international nanosafety forum. The main project goal is to develop innovative concepts and reliable methods for characterizing ENP in workplace air with novel, portable and easy-to-use devices suitable for workplaces.

  3. 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.

  4. 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.

  5. Metadata Wizard: an easy-to-use tool for creating FGDC-CSDGM metadata for geospatial datasets in ESRI ArcGIS Desktop

    Science.gov (United States)

    Ignizio, Drew A.; O'Donnell, Michael S.; Talbert, Colin B.

    2014-01-01

    Creating compliant metadata for scientific data products is mandated for all federal Geographic Information Systems professionals and is a best practice for members of the geospatial data community. However, the complexity of the The Federal Geographic Data Committee’s Content Standards for Digital Geospatial Metadata, the limited availability of easy-to-use tools, and recent changes in the ESRI software environment continue to make metadata creation a challenge. Staff at the U.S. Geological Survey Fort Collins Science Center have developed a Python toolbox for ESRI ArcDesktop to facilitate a semi-automated workflow to create and update metadata records in ESRI’s 10.x software. The U.S. Geological Survey Metadata Wizard tool automatically populates several metadata elements: the spatial reference, spatial extent, geospatial presentation format, vector feature count or raster column/row count, native system/processing environment, and the metadata creation date. Once the software auto-populates these elements, users can easily add attribute definitions and other relevant information in a simple Graphical User Interface. The tool, which offers a simple design free of esoteric metadata language, has the potential to save many government and non-government organizations a significant amount of time and costs by facilitating the development of The Federal Geographic Data Committee’s Content Standards for Digital Geospatial Metadata compliant metadata for ESRI software users. A working version of the tool is now available for ESRI ArcDesktop, version 10.0, 10.1, and 10.2 (downloadable at http:/www.sciencebase.gov/metadatawizard).

  6. Performance of an easy-to-use prediction model for renal patient survival: an external validation study using data from the ERA-EDTA Registry.

    Science.gov (United States)

    Hemke, Aline C; Heemskerk, Martin B A; van Diepen, Merel; Kramer, Anneke; de Meester, Johan; Heaf, James G; Abad Diez, José Maria; Torres Guinea, Marta; Finne, Patrik; Brunet, Philippe; Vikse, Bjørn E; Caskey, Fergus J; Traynor, Jamie P; Massy, Ziad A; Couchoud, Cécile; Groothoff, Jaap W; Nordio, Maurizio; Jager, Kitty J; Dekker, Friedo W; Hoitsma, Andries J

    2018-01-16

    An easy-to-use prediction model for long-term renal patient survival based on only four predictors [age, primary renal disease, sex and therapy at 90 days after the start of renal replacement therapy (RRT)] has been developed in The Netherlands. To assess the usability of this model for use in Europe, we externally validated the model in 10 European countries. Data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry were used. Ten countries that reported individual patient data to the registry on patients starting RRT in the period 1995-2005 were included. Patients prediction model was evaluated for the 10- (primary endpoint), 5- and 3-year survival predictions by assessing the calibration and discrimination outcomes. We used a data set of 136 304 patients from 10 countries. The calibration in the large and calibration plots for 10 deciles of predicted survival probabilities showed average differences of 1.5, 3.2 and 3.4% in observed versus predicted 10-, 5- and 3-year survival, with some small variation on the country level. The concordance index, indicating the discriminatory power of the model, was 0.71 in the complete ERA-EDTA Registry cohort and varied according to country level between 0.70 and 0.75. A prediction model for long-term renal patient survival developed in a single country, based on only four easily available variables, has a comparably adequate performance in a wide range of other European countries. © The Author(s) 2018. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Characterisation of human induced pluripotent stem cell-derived endothelial cells under shear stress using an easy-to-use microfluidic cell culture system.

    Science.gov (United States)

    Ohtani-Kaneko, Rsituko; Sato, Kenjiro; Tsutiya, Atsuhiro; Nakagawa, Yuka; Hashizume, Kazutoshi; Tazawa, Hidekatsu

    2017-10-09

    Induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) can contribute to elucidating the pathogenesis of heart and vascular diseases and developing their treatments. Their precise characteristics in fluid flow however remain unclear. Therefore, the aim of the present study is to characterise these features. We cultured three types of ECs in a microfluidic culture system: commercially available human iPS-ECs, human umbilical vein endothelial cells (HUVECs) and human umbilical artery endothelial cells (HUAECs). We then examined the mRNA expression levels of endothelial marker gene cluster of differentiation 31 (CD31), fit-related receptor tyrosine kinase (Flk-1), and the smooth muscle marker gene smooth muscle alpha-actin, and investigated changes in plasminogen activator inhibitor-1 (PAI-1) secretion and intracellular F-actin arrangement following heat stress. We also compared expressions of the arterial and venous marker genes ephrinB2 and EphB4, and the endothelial gap junction genes connexin (Cx) 37, 40, and 43 under fluidic shear stress to determine their arterial or venous characteristics. We found that iPS-ECs had similar endothelial marker gene expressions and exhibited similar increases in PAI-1 secretion under heat stress as HUVECs and HUAECs. In addition, F-actin arrangement in iPSC-ECs also responded to heat stress, as previously reported. However, they had different expression patterns of arterial and venous marker genes and Cx genes under different fluidic shear stress levels, showing that iPSC-ECs exhibit different characteristics from arterial and venous ECs. This microfluidic culture system equipped with variable shear stress control will provide an easy-to-use assay tool to examine characteristics of iPS-ECs generated by different protocols in various laboratories and contribute to basic and applied biomedical researches on iPS-ECs.

  8. 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.

  9. Effects of easy-to-use protein-rich energy bar on energy balance, physical activity and performance during 8 days of sustained physical exertion.

    Directory of Open Access Journals (Sweden)

    Minna M Tanskanen

    Full Text Available BACKGROUND: Previous military studies have shown an energy deficit during a strenuous field training course (TC. This study aimed to determine the effects of energy bar supplementation on energy balance, physical activity (PA, physical performance and well-being and to evaluate ad libitum fluid intake during wintertime 8-day strenuous TC. METHODS: Twenty-six men (age 20±1 yr. were randomly divided into two groups: The control group (n = 12 had traditional field rations and the experimental (Ebar group (n = 14 field rations plus energy bars of 4.1 MJ•day(-1. Energy (EI and water intake was recorded. Fat-free mass and water loss were measured with deuterium dilution and elimination, respectively. The energy expenditure was calculated using the intake/balance method and energy availability as (EI/estimated basal metabolic rate. PA was monitored using an accelerometer. Physical performance was measured and questionnaires of upper respiratory tract infections (URTI, hunger and mood state were recorded before, during and after TC. RESULTS: Ebar had a higher EI and energy availability than the controls. However, decreases in body mass and fat mass were similar in both groups representing an energy deficit. No differences were observed between the groups in PA, water balance, URTI symptoms and changes in physical performance and fat-free mass. Ebar felt less hunger after TC than the controls and they had improved positive mood state during the latter part of TC while controls did not. Water deficit associated to higher PA. Furthermore, URTI symptoms and negative mood state associated negatively with energy availability and PA. CONCLUSION: An easy-to-use protein-rich energy bars did not prevent energy deficit nor influence PA during an 8-day TC. The high content of protein in the bars might have induced satiation decreasing energy intake from field rations. PA and energy intake seems to be primarily affected by other factors than energy

  10. 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 ...

  11. 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.

  12. 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/.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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)

  1. 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.

  2. 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

  3. 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

    magnetoencephalography (MEG), by far the most widespread application of biomagnetism with systems containing typically 300 sensors cooled to liquid-helium temperature, 4.2 K. Two important clinical applications are presurgical mapping of focal epilepsy and of eloquent cortex in brain-tumor patients. Reducing the sensor-to-brain separation and the system noise level would both improve spatial resolution. The very recent commercial innovation that replaces the need for frequent manual transfer of liquid helium with an automated system that collects and liquefies the gas and transfers the liquid to the dewar will make MEG systems more accessible. A highly promising means of placing the sensors substantially closer to the scalp for MEG is to use high-transition-temperature (high-T c) SQUID sensors and flux transformers (chapter 3). Operation of these devices at liquid-nitrogen temperature, 77 K, enables one to minimize or even omit metallic thermal insulation between the sensors and the dewar. Noise levels of a few fT Hz-1/2 have already been achieved, and lower values are likely. The dewars can be made relatively flexible, and thus able to be placed close to the skull irrespective of the size of the head, potentially providing higher spatial resolution than liquid-helium based systems. The successful realization of a commercial high-T c MEG system would have a major commercial impact. Chapter 4 introduces the concept of SQUID-based ultra-low-field magnetic resonance imaging (ULF MRI) operating at typically several kHz, some four orders of magnitude lower than conventional, clinical MRI machines. Potential advantages of ULF MRI include higher image contrast than for conventional MRI, enabling methodologies not currently available. Examples include screening for cancer without a contrast agent, imaging traumatic brain injury (TBI) and degenerative diseases such as Alzheimer’s, and determining the elapsed time since a stroke. The major current problem with ULF MRI is that its signal

  4. 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.

  5. 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.

  6. 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.)

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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

  12. 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.).

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. SQUID (superconducting quantum interference device) arrays for simultaneous magnetic measurements: Calibration and source localization performance

    Science.gov (United States)

    Kaufman, Lloyd; Williamson, Samuel J.; Costaribeiro, P.

    1988-02-01

    Recently developed small arrays of SQUID-based magnetic sensors can, if appropriately placed, locate the position of a confined biomagnetic source without moving the array. The authors present a technique with a relative accuracy of about 2 percent for calibrating such sensors having detection coils with the geometry of a second-order gradiometer. The effects of calibration error and magnetic noise on the accuracy of locating an equivalent current dipole source in the human brain are investigated for 5- and 7-sensor probes and for a pair of 7-sensor probes. With a noise level of 5 percent of peak signal, uncertainties of about 20 percent in source strength and depth for a 5-sensor probe are reduced to 8 percent for a pair of 7-sensor probes, and uncertainties of about 15 mm in lateral position are reduced to 1 mm, for the configuration considered.

  20. 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

  1. 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

  2. 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)

  3. 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)

  4. Non-contact optical Liquid Level Sensors

    Science.gov (United States)

    Kiseleva, L. L.; Tevelev, L. V.; Shaimukhametov, R. R.

    2016-06-01

    Information about characteristics of the optical liquid level sensor are present. Sensors are used to control of the light level limit fluid - water, kerosene, alcohol, solutions, etc. Intrinsically safe, reliable and easy to use. The operating principle of the level sensor is an optoelectronic infrared device.

  5. Sensors

    CERN Document Server

    Pigorsch, Enrico

    1997-01-01

    This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...

  6. Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)

    1999-10-01

    A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)

  7. 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

  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. 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

  10. 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

  11. 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

  12. Bioequivalence of Liposome-Entrapped Paclitaxel Easy-To-Use (LEP-ETU) formulation and paclitaxel in polyethoxylated castor oil: a randomized, two-period crossover study in patients with advanced cancer.

    Science.gov (United States)

    Slingerland, Marije; Guchelaar, Henk-Jan; Rosing, Hilde; Scheulen, Max E; van Warmerdam, Laurence J C; Beijnen, Jos H; Gelderblom, Hans

    2013-12-01

    Preclinical studies comparing paclitaxel formulated with polyethoxylated castor oil with the sonicated formulation of liposome-entrapped paclitaxel (LEP) have demonstrated that LEP was associated with reduced toxicity while maintaining similar efficacy. Preliminary studies on the pharmacokinetics in patients support earlier preclinical data, which suggested that the LEP Easy-to-Use (LEP-ETU) formulation and paclitaxel formulated with castor oil may have comparable pharmacokinetic properties. Our objectives were: (1) to determine bioequivalence of paclitaxel pharmaceutically formulated as LEP-ETU (test) and paclitaxel formulated with castor oil (reference); and (2) to assess the tolerability of LEP-ETU following intravenous administration. Patients with advanced cancer were studied in a randomized, 2-period crossover bioequivalence study. Patients received paclitaxel 175 mg/m(2) administered as an intravenous infusion over 180 minutes, either as a single-treatment cycle of the test formulation followed by a single-treatment cycle of the reference formulation, or vice versa. Thirty-two of 58 patients were evaluable and were included in the analysis for bioequivalence. Mean total paclitaxel Cmax values for the test and reference formulations were 4955.0 and 5108.8 ng/mL, respectively. Corresponding AUC0-∞ values were 15,853.8 and 18,550.8 ng·h/mL, respectively. Treatment ratios of the geometric means were 97% (90% CI, 91%-103%) for Cmax and 84% (90% CI, 80%-90%) for AUC0-∞. These results met the required 80% to 125% bioequivalence criteria. The most frequently reported adverse events after LEP-ETU administration were fatigue, alopecia, and myalgia. At the studied dose regimen, LEP-ETU showed bioequivalence with paclitaxel formulated with polyethoxylated castor oil. © 2013 Elsevier HS Journals, Inc. All rights reserved.

  13. 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

  14. 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)

  15. 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.

  16. 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)

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Development of X-ray microcalorimeters using transition edge sensors

    International Nuclear Information System (INIS)

    Ukibe, M; Hirayama, F.; Tanaka, K.; Koyanagi, M.; Ohkubo, M.; Kobayashi, N.; Morooka, T.; Chinone, K.

    2000-01-01

    We are developing X-ray microcalorimeters using superconducting transition edge sensors (TESs), which can be operated at relatively high temperatures in a 3 He cryostat, and DC-SQUID current amplifiers to realize an X-ray spectroscopy with a high energy resolution and a high counting rate. The TESs are proximity bilayers of Ti and Au on SiN x membranes with 500-1000 nm thicknesses. The typical TES has a T c value of 0.4 K and a ΔT c value of 2 mK. Two types of DC-SQUID amplifiers were developed; the single stage with 200-series SQUIDs and the double stage with an input SQUID and 50-series SQUIDs. The X-ray detection experiment is in progress. (author)

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Magnetorelaxometry of few Fe3O4 nanoparticles at 77 K employing a self-compensated SQUID magnetometer

    International Nuclear Information System (INIS)

    Guillaume, Alexander; Scholtyssek, Jan M.; Lak, Aidin; Kassner, Alexander; Ludwig, Frank; Schilling, Meinhard

    2016-01-01

    Magnetic nanoparticles (MNPs) are of great interest for industrial and medical applications. Therefore, the properties of the particles have to be well controlled. Several magnetic measurement schemes have been developed in order to determine particle parameters such as size distribution and structural properties. In general, systems are designed either for the analysis of large amounts of MNP (≫1000) or for single particle investigation. Up to now, the region in between has been less studied. However, small and well defined amounts of MNPs are of high interest, e.g. for the systematic investigation of particle–particle interactions. In this paper, we present a method using electron beam lithographic preparation of small amounts of MNPs directly on a self-compensating high-temperature superconducting quantum interference device (SQUID) with micrometer dimensions which is insensitive to homogeneous fields and first order gradients but very sensitive to internal magnetic dipole fields. Magnetorelaxometry (MRX) measurements were carried out at 77 K sample temperature in a magnetically shielded room in order to analyze the dynamic behavior of MNP samples and to evaluate the detection limit of our SQUID sensors. Calculations based on the magnetic moment superposition model (MSM) and finite element simulations (FEM) indicate that the MNP samples can be fabricated in a well-defined way by the presented method. Based on MRX measurements of a sample with 200 single-core magnetite MNPs with core diameters of 12 nm, we estimate the detection limit of our SQUID MRX setup as 70 MNPs. - Highlights: • Novel self-compensated superconducting quantum interference device (SQUID). • Electron-beam lithographical patterning of magnetic nanoparticles directly on SQUID. • Magnetorelaxometric detection of 200 nanoparticles with diameter of 12 nm at 77 K. • FEM simulations provide detection limit of less than 100 nanoparticles.

  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. Sensor

    OpenAIRE

    Gleeson, Helen; Dierking, Ingo; Grieve, Bruce; Woodyatt, Christopher; Brimicombe, Paul

    2015-01-01

    An electrical temperature sensor (10) comprises a liquid crystalline material (12). First and second electrically conductive contacts (14), (16), having a spaced relationship there between, contact the liquid crystalline material (12). An electric property measuring device is electrically connected to the first and second contacts (14), (16) and is arranged to measure an electric property of the liquid crystalline material (12). The liquid crystalline material (12) has a transition temperatur...

  2. High Performance Fiber-Optic Sensor for Environmental Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research (LGR) proposes to develop a low-cost, compact, lightweight, rugged and easy-to-use environmental monitoring optical fiber sensor device based on...

  3. Detection of nuclear magnetic resonance in the microtesla range using a high Tc dc-SQUID

    Science.gov (United States)

    Wang, Ning; Jin, Yirong; Li, Shao; Ren, Yufeng; Tian, Ye; Chen, Yingfei; Li, Jie; Chen, Genghua; Zheng, Dongning

    2012-12-01

    We have detected the ultra-low field nuclear magnetic resonance signal from water samples using a high-Tc dc-SQUID sensor. The measurements were carried out in a homemade magnetically shielded room. Resonance spectra of 1H from tap water and other substance samples were obtained in the field range from 7-110μT corresponding to resonance frequency 300-4.68kHz. Two kind of experimental systems were built, the first one is a directly coupled system, its signal to noise ratio in a single-shot measurement is around 4 for about 15 ml water. The second one used a Cu coil to transfer the flux to the SQUID sensor. Signal to noise ratio was improved to about 20 in a single-shot measurement for 5ml water, which benefits from the improvement of coupling efficiency. The effect of residual gradient in the magnetically shielded room was also investigated. J-coupling of 2,2,2-Trifluoroethyl alcohol was measured, the peaks are consistent with high field results.

  4. Detection of nuclear magnetic resonance in the microtesla range using a high Tc dc-SQUID

    International Nuclear Information System (INIS)

    Wang Ning; Jin Yirong; Li Shao; Ren Yufeng; Tian Ye; Chen Yingfei; Li Jie; Chen Genghua; Zheng Dongning

    2012-01-01

    We have detected the ultra-low field nuclear magnetic resonance signal from water samples using a high-T c dc-SQUID sensor. The measurements were carried out in a homemade magnetically shielded room. Resonance spectra of 1 H from tap water and other substance samples were obtained in the field range from 7-110μT corresponding to resonance frequency 300-4.68kHz. Two kind of experimental systems were built, the first one is a directly coupled system, its signal to noise ratio in a single-shot measurement is around 4 for about 15 ml water. The second one used a Cu coil to transfer the flux to the SQUID sensor. Signal to noise ratio was improved to about 20 in a single-shot measurement for 5ml water, which benefits from the improvement of coupling efficiency. The effect of residual gradient in the magnetically shielded room was also investigated. J-coupling of 2,2,2-Trifluoroethyl alcohol was measured, the peaks are consistent with high field results.

  5. 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.

  6. 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.

  7. 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.

  8. 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.))

  9. 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...

  10. 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.

  11. 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

  12. 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)

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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/

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Electrochemical Sensors for Clinic Analysis

    Directory of Open Access Journals (Sweden)

    Guang Li

    2008-03-01

    Full Text Available Demanded by modern medical diagnosis, advances in microfabrication technology have led to the development of fast, sensitive and selective electrochemical sensors for clinic analysis. This review addresses the principles behind electrochemical sensor design and fabrication, and introduces recent progress in the application of electrochemical sensors to analysis of clinical chemicals such as blood gases, electrolytes, metabolites, DNA and antibodies, including basic and applied research. Miniaturized commercial electrochemical biosensors will form the basis of inexpensive and easy to use devices for acquiring chemical information to bring sophisticated analytical capabilities to the non-specialist and general public alike in the future.

  6. ALAT: Finally an Easy To Use Adaptation Authoring Tool

    NARCIS (Netherlands)

    De Bra, Paul; Stash, Natalia; Boereboom, Wouter; Chen, Celine; Den Ouden, Joris; Kunstman, Martijn; Oostrum, John; Verbakel, Egon

    2016-01-01

    Research papers about adaptive hypermedia systems, frameworks or applications tend to focus on the end-result: how the applications are used by end-users, how adaptation improves user satisfaction, learning, etc. What they do not describe is how difficult and labor-intensive the creation of the

  7. 6 Sigma DFSS technique which is easy to use

    International Nuclear Information System (INIS)

    2002-01-01

    This book gives descriptions of 6 sigma DFSS technique. The contents of this book are storm of change, way of problem and solution, importance of customer satisfaction, quality improvement is key of customer satisfaction, quality improvement equals cost cutting, quality aim in perfect level, finding basic cause, data is life, standardization is fundamentals of all activity for improvement, chief, Chang's house, collection of data, setting goal to improve, experiment is the best way, importance of the last step, x control power of 6 sigma and Let's go six-sigma.

  8. Dexterous Manipulation: Making Remote Manipulators Easy to Use

    International Nuclear Information System (INIS)

    HARRIGAN, RAYMOND W.; BENNETT, PHIL C.

    2001-01-01

    Perhaps the most basic barrier to the widespread deployment of remote manipulators is that they are very difficult to use. Remote manual operations are fatiguing and tedious, while fully autonomous systems are seldom able to function in changing and unstructured environments. An alternative approach to these extremes is to exploit computer control while leaving the operator in the loop to take advantage of the operator's perceptual and decision-making capabilities. This report describes research that is enabling gradual introduction of computer control and decision making into operator-supervised robotic manipulation systems, and its integration on a commercially available, manually controlled mobile manipulator

  9. 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.

  10. 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

  11. SQUID based cryogenic current comparator for measurements of the dark current of superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R.; Nawrodt, R. [Friedrich Schiller Univ. Jena (Germany); Peters, A. [GSI Darmstadt (Germany); Knaack, K.; Wendt, M.; Wittenburg, K. [DESY Hamburg (Germany)

    2005-07-01

    The linear accelerator technology, based on super-conducting L-band (1.3 GHz) is currently under study at DESY (Hamburg, Germany). The two 10 km long main Linacs will be equipped with a total of nearly 20.000 cavities. The dark current due to the emission of electrons in these high gradient field super-conducting cavities is an unwanted particle source. A newly high performance SQUID based measurement system for detecting dark currents is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the pA range with a measurement bandwidth of up to 70 kHz. The use of a cryogenic current comparator as dark current sensor has some important advantages: -) the measurement of the absolute value of the dark current, -) the non-dependence on the electron trajectories, -) the accurate absolute calibration with an additional wire loop, and -) extremely high resolution.

  12. A high-resolution mK-calorimeter applying SQUID-thermometry

    Energy Technology Data Exchange (ETDEWEB)

    Reifenberger, Andreas; Leps, Norman; Fleischmann, Andreas; Pies, Christian; Enss, Christian; Klingeler, Ruediger [Kirchhoff-Institut fuer Physik, Universitaet Heidelberg, INF 227,69120 Heidelberg (Germany)

    2012-07-01

    A new calorimeter for measuring single-crystalline samples of mg-size at ultra-low temperatures is described. Thermometry is done by means of a paramagnetic sensor material (Er-doped Au) in a low magnetic field. A temperature change results in a magnetization change which can be read out as change in magnetic flux by a superconducting quantum interference device (SQUID). This enables measurements in a wide temperature range (theoretically from 1 mK-1 K) with very high sensitivities. The bolometric design exhibits low addenda heat capacity and allows measurements of heat capacities from nJ/K to {mu}J/K by means of a temperature-relaxation method. The performance of the device is compared to a commercially available Quantum Design calorimeter in elsewise unchanged experimental settings in the temperature range from 15 mK to 500 mK.

  13. 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 ...

  14. 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 ...

  15. 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 ...

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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 ...

  1. 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 ...

  2. High-Tc dc-SQUID gradiometers in flip-chip configuration

    International Nuclear Information System (INIS)

    Peiselt, K; Schmidl, F; Linzen, S; Anton, A S; Huebner, U; Seidel, P

    2003-01-01

    We describe a new design of a gradiometric flip-chip antenna, which is inductively coupled to a dc-SQUID gradiometer. Both components are patterned out of thin films of the high-T c superconductor YBa 2 Cu 3 O 7-x (YBCO). For the flip-chip antenna, a 40 mm x 10 mm SrTiO 3 single crystalline substrate is used, while the gradiometer sensors are prepared on 10 mm x 10 mm SrTiO 3 bicrystal substrates. Special attention is paid to the inductive coupling between the flip-chip antenna and the read-out gradiometer antenna. We investigate different designs of coupling loops in order to optimize the coupling inductance between both components of the sensor. With optimized coupling the sensor achieves a field-gradient resolution of 12 fT cm -1 Hz -1/2 in the white noise region and of 310 fT cm -1 Hz -1/2 at 1 Hz in the unshielded laboratory environment

  3. High-Tc dc-SQUID gradiometers in flip-chip configuration

    Science.gov (United States)

    Peiselt, K.; Schmidl, F.; Linzen, S.; Anton, A. S.; Hübner, U.; Seidel, P.

    2003-12-01

    We describe a new design of a gradiometric flip-chip antenna, which is inductively coupled to a dc-SQUID gradiometer. Both components are patterned out of thin films of the high-Tc superconductor YBa2Cu3O7-x (YBCO). For the flip-chip antenna, a 40 mm × 10 mm SrTiO3 single crystalline substrate is used, while the gradiometer sensors are prepared on 10 mm × 10 mm SrTiO3 bicrystal substrates. Special attention is paid to the inductive coupling between the flip-chip antenna and the read-out gradiometer antenna. We investigate different designs of coupling loops in order to optimize the coupling inductance between both components of the sensor. With optimized coupling the sensor achieves a field-gradient resolution of 12 fT cm-1 Hz-1/2 in the white noise region and of 310 fT cm-1 Hz-1/2 at 1 Hz in the unshielded laboratory environment.

  4. Development of a highly sensitive current and position monitor with HTS squids and an HTS magnetic shield

    International Nuclear Information System (INIS)

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

    2005-01-01

    A highly sensitive current and position monitor with HTS (High-Temperature Superconducting) SQUIDs (Superconducting QUantum Interference Device) and an HTS magnetic shield for the measurement of the intensity of faint beams, such as a radioisotope beam, has been developed for the RIKEN RI beam factory project. The HTS magnetic shield and the HTS current sensor including the HTS SQUID are cooled by a low-vibration pulse-tube refrigerator. Both the HTS magnetic shield and the HTS current sensor were fabricated by dip-coating a thin Bi 2 -Sr 2 -Ca 2 -Cu 3 -O x (Bi-2223) layer on 99.9% MgO ceramic substrates. The HTS technology enables us to develop a system equipped with a downsized and highly sensitive current monitor. Recently, a prototype system was completed and installed in the beam transport line of the RIKEN Ring Cyclotron to measure the DC-current of high-energy heavy-ion beams. As a result, we succeeded in measuring the intensity of the 600 nA 40 Ar 17+ beam (95 MeV/u). We describe the present status of the monitor system and the results of the beam measurements. (author)

  5. Nanobridge SQUIDs as calorimetric inductive particle detectors

    International Nuclear Information System (INIS)

    Gallop, John; Cox, David; Hao, Ling

    2015-01-01

    Superconducting transition edge sensors (TESs) have made dramatic progress since their invention some 65 years ago (Andrews et al 1949 Phys. Rev. 76 154–155; Irwin and Hilton 2005 Topics Appl. Phys. 99 63–149) until now there are major imaging arrays of TESs with as many as 7588 separate sensors. These are extensively used by astronomers for some ground-breaking observations (Hattori et al 2013 Nucl. Instrum. Methods Phys. Res. A 732 299–302). The great success of TES systems has tended to overshadow other superconducting sensor developments. However there are other types (Sobolewski et al 2003 IEEE Trans. Appl. Supercond. 13 1151–7; Hadfield 2009 Nat. Photonics 3 696–705) which are discussed in papers within this special edition of the journal. Here we describe a quite different type of detector, also applicable to single photon detection but possessing possible advantages (higher sensitivity, higher operating temperature) over the conventional TES, at least for single detectors. (paper)

  6. 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.

  7. 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

  8. 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.

  9. Operation of transition-edge sensors with excess thermal noise

    International Nuclear Information System (INIS)

    Maasilta, I J; Kinnunen, K M; Nuottajaervi, A K; Leppaeniemi, J; Luukanen, A

    2006-01-01

    The superconducting transition-edge sensor (TES) is currently one of the most attractive choices for ultra-high resolution calorimetry in the keV x-ray band, and is being considered for future ESA and NASA missions. We have performed a study on the noise characteristics of Au/Ti bilayer TESs, at operating temperatures around ∼100 mK, with the SQUID readout at 1.5 K. Experimental results indicate that without modifications the back-action noise from the SQUID chip degrades the noise characteristics significantly. We present a simple and effective solution to the problem: by installing an extra shunt resistor which absorbs the excess radiation from the SQUID input, we have reduced the excess thermal (photon) noise power down by approximately a factor of five, allowing high resolution operation of the sensors

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.)

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

    Science.gov (United States)

    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.

  17. 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

  18. 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...

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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)

  5. 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.

  6. 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

  7. 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.

  8. Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

    Science.gov (United States)

    Prele, D.

    2015-08-01

    As we have seen for digital camera market and a sensor resolution increasing to "megapixels", all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, "simple" and "efficient" techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described.

  9. Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

    International Nuclear Information System (INIS)

    Prele, D.

    2015-01-01

    As we have seen for digital camera market and a sensor resolution increasing to 'megapixels', all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, 'simple' and 'efficient' techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described

  10. 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...

  11. 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

  12. 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.

  13. 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)

  14. 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)

  15. 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.

  16. 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.)

  17. 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...

  18. 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

  19. 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

  20. 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.

  1. Scanning-SQUID investigation of spin-orbit torque acting on yttrium iron garnet devices

    Science.gov (United States)

    Rosenberg, Aaron J.; Jermain, Colin L.; Aradhya, Sriharsha V.; Brangham, Jack T.; Nowack, Katja C.; Kirtley, John R.; Yang, Fengyuan; Ralph, Daniel C.; Moler, Kathryn A.

    Successful manipulation of electrically insulating magnets, such as yttrium iron garnet, by by current-driven spin-orbit torques could provide a highly efficient platform for spintronic memory. Compared to devices fabricated using magnetic metals, magnetic insulators have the advantage of the ultra-low magnetic damping and the elimination of shunting currents in the magnet that reduce the torque efficiency. Here, we apply current in the spin Hall metal β-Ta to manipulate the magnetic orientation of micron-sized, electrically-insulating yttrium iron garnet devices. We do not observe spin-torque switching even for applied currents well above the critical current expected in a macrospin switching model. This suggests either inefficient transfer of spin torque at our Ta/YIG interface or a breakdown of the macrospin approximation. This work is supported by FAME, one of six centers of STARnet sponsored by MARCO and DARPA. The SQUID microscope and sensors were developed with support from the NSF-sponsored Center NSF-NSEC 0830228, and from NSF IMR-MIP 0957616.

  2. 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.

  3. 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.

  4. 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

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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

  16. Benchmarking for On-Scalp MEG Sensors.

    Science.gov (United States)

    Xie, Minshu; Schneiderman, Justin F; Chukharkin, Maxim L; Kalabukhov, Alexei; Riaz, Bushra; Lundqvist, Daniel; Whitmarsh, Stephen; Hamalainen, Matti; Jousmaki, Veikko; Oostenveld, Robert; Winkler, Dag

    2017-06-01

    We present a benchmarking protocol for quantitatively comparing emerging on-scalp magnetoencephalography (MEG) sensor technologies to their counterparts in state-of-the-art MEG systems. As a means of validation, we compare a high-critical-temperature superconducting quantum interference device (high T c SQUID) with the low- T c SQUIDs of an Elekta Neuromag TRIUX system in MEG recordings of auditory and somatosensory evoked fields (SEFs) on one human subject. We measure the expected signal gain for the auditory-evoked fields (deeper sources) and notice some unfamiliar features in the on-scalp sensor-based recordings of SEFs (shallower sources). The experimental results serve as a proof of principle for the benchmarking protocol. This approach is straightforward, general to various on-scalp MEG sensors, and convenient to use on human subjects. The unexpected features in the SEFs suggest on-scalp MEG sensors may reveal information about neuromagnetic sources that is otherwise difficult to extract from state-of-the-art MEG recordings. As the first systematically established on-scalp MEG benchmarking protocol, magnetic sensor developers can employ this method to prove the utility of their technology in MEG recordings. Further exploration of the SEFs with on-scalp MEG sensors may reveal unique information about their sources.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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...

  2. 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/

  3. 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...

  4. 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...

  5. 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...

  6. 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

  7. 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

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

    Science.gov (United States)

    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.

  9. 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.

  10. 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...

  11. 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.

  12. Equilibrium vortex motion in two- and three-dimensional superconductors studied with a dc SQUID

    International Nuclear Information System (INIS)

    Shaw, T.J.; Lawrence Berkeley National Lab., CA

    1997-10-01

    The equilibrium motion of vortices in two- and three-dimensional superconductors has been studied with a dc Superconducting QUantum Interference Device (SQUID). This technique has the advantage of probing the system in a non-invasive manner as well as providing dynamic information over many decades in frequency. Through measurements of the spectral density of magnetic flux noise, S Φ (ω), as a function of temperature and applied magnetic field, the effects of proton and heavy ion irradiation on flux noise in crystals of YBa 2 Cu 3 O 7-δ have been measured and compared with the effects on the critical current, J c . Both proton and heavy ion irradiation proved effective at reducing S Φ (ω), with proton irradiation having a larger effect. Measurement of S Φ (ω) due to the equilibrium Kosterlitz-Thouless-Berezinskii transition in two-dimensional Josephson Junction Arrays (JJAs) was studied as a function of temperature for three different arrays and using three different sensors. S Φ is shown to obey dynamic scaling over as many as five decades in frequency, and estimates are made for the dynamic critical exponent z. An analytic theory for the high- and low-frequency behavior of S Φ (ω) is presented and compared to the measured data, with the result that the low-frequency behavior is well described by the theory but the high-frequency behavior is not. Other theories and numerical simulations are described and compared with the data, but none are completely satisfactory. Lastly, suggestions for necessary further theoretical work and possible future experimental work are suggested

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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....

  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. 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.)

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  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. 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

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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}.

  14. 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.

  15. 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/.

  16. 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.

  17. 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

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. 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

  2. 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.)

  3. Localizing on-scalp MEG sensors using an array of magnetic dipole coils.

    Science.gov (United States)

    Pfeiffer, Christoph; Andersen, Lau M; Lundqvist, Daniel; Hämäläinen, Matti; Schneiderman, Justin F; Oostenveld, Robert

    2018-01-01

    Accurate estimation of the neural activity underlying magnetoencephalography (MEG) signals requires co-registration i.e., determination of the position and orientation of the sensors with respect to the head. In modern MEG systems, an array of hundreds of low-Tc SQUID sensors is used to localize a set of small, magnetic dipole-like (head-position indicator, HPI) coils that are attached to the subject's head. With accurate prior knowledge of the positions and orientations of the sensors with respect to one another, the HPI coils can be localized with high precision, and thereby the positions of the sensors in relation to the head. With advances in magnetic field sensing technologies, e.g., high-Tc SQUIDs and optically pumped magnetometers (OPM), that require less extreme operating temperatures than low-Tc SQUID sensors, on-scalp MEG is on the horizon. To utilize the full potential of on-scalp MEG, flexible sensor arrays are preferable. Conventional co-registration is impractical for such systems as the relative positions and orientations of the sensors to each other are subject-specific and hence not known a priori. Herein, we present a method for co-registration of on-scalp MEG sensors. We propose to invert the conventional co-registration approach and localize the sensors relative to an array of HPI coils on the subject's head. We show that given accurate prior knowledge of the positions of the HPI coils with respect to one another, the sensors can be localized with high precision. We simulated our method with realistic parameters and layouts for sensor and coil arrays. Results indicate co-registration is possible with sub-millimeter accuracy, but the performance strongly depends upon a number of factors. Accurate calibration of the coils and precise determination of the positions and orientations of the coils with respect to one another are crucial. Finally, we propose methods to tackle practical challenges to further improve the method.

  4. 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.

  5. 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)

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

    Science.gov (United States)

    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.

  7. 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.

  8. 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)

  9. 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

  10. 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

  11. 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...

  12. 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, ...

  13. 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

  14. 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...

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

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

    Science.gov (United States)

    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.

  12. 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

  13. 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

  14. 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.

  15. 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)

  16. 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.

  17. Noninvasive wearable sensor for indirect glucometry.

    Science.gov (United States)

    Zilberstein, Gleb; Zilberstein, Roman; Maor, Uriel; Righetti, Pier Giorgio

    2018-04-02

    A noninvasive mini-sensor for blood glucose concentration assessment has been developed. The monitoring is performed by gently pressing a wrist or fingertip onto the chemochromic mixture coating a thin glass or polymer film positioned on the back panel of a smart watch with PPG/HRM (photoplethysmographic/heart rate monitoring sensor). The various chemochromic components measure the absolute values of the following metabolites present in the sweat: acetone, acetone beta-hydroxybutirate, aceto acetate, water, carbon dioxide, lactate anion, pyruvic acid, Na and K salts. Taken together, all these parameters give information about blood glucose concentration, calculated via multivariate analysis based on neural network algorithms built into the sensor. The Clarke Error Grid shows an excellent correlation between data measured by the standard invasive glucose analyser and the present noninvasive sensor, with all points aligned along a 45-degree diagonal and contained almost exclusively in sector A. Graphs measuring glucose levels five times a day (prior, during and after breakfast and prior, during and after lunch), for different individuals (males and females) show a good correlation between the two curves of conventional, invasive meters vs. the noninvasive sensor, with an error of ±15%. This novel, noninvasive sensor for indirect glucometry is fully miniaturized, easy to use and operate and could represent a valid alternative in clinical settings and for individual, personal users, to current, invasive tools. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.)

  4. 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...

  5. 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.

  6. 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 ...

  7. 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

  8. 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...

  9. 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.

  10. 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.

  11. 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, ...

  12. 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)

  13. 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)

  14. 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.

  15. 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

  16. 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)

  17. 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.

  18. 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)

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Taste sensor; Mikaku sensor

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K. [Kyushu University, Fukuoka (Japan)

    1998-03-05

    This paper introduces a taste sensor having a lipid/polymer membrane to work as a receptor of taste substances. The paper describes the following matters: this sensor uses a hollow polyvinyl chloride rod filled with KCl aqueous solution, and placed with silver and silver chloride wires, whose cross section is affixed with a lipid/polymer membrane as a lipid membrane electrode to identify taste from seven or eight kinds of response patterns of electric potential output from the lipid/polymer membrane; measurements of different substances presenting acidic taste, salty taste, bitter taste, sweet taste and flavor by using this sensor identified clearly each taste (similar response is shown to a similar taste even if the substances are different); different responses are indicated on different brands of beers; from the result of measuring a great variety of mineral waters, a possibility was suggested that this taste sensor could be used for water quality monitoring sensors; and application of this taste sensor may be expected as a maturation control sensor for Japanese sake (wine) and miso (bean paste) manufacturing. 2 figs., 1 tab.

  14. Enchondroma vs. chondrosarcoma: A simple, easy-to-use, new magnetic resonance sign

    International Nuclear Information System (INIS)

    Vanel, Daniel; Kreshak, Jennifer; Larousserie, Frédérique; Alberghini, Marco; Mirra, Joe; De Paolis, Massimiliano; Picci, Piero

    2013-01-01

    Introduction: There is no clear radiologic or pathologic agreement on the differences between enchondroma and conventional chondrosarcoma, which has huge therapeutic consequences. Microscopically, an enchondroma is composed of “islands of intramedullary hyaline cartilage surrounded by marrow fat”, and a chondrosarcoma a “diffuse cartilaginous replacement (invasion) of the marrow which leads to complete ‘trapping’ of host lamellar bone trabeculae.” The marrow around islands of cartilage should be detectable on magnetic resonance imaging (MR). Enchondroma may be the precursor of chondrosarcoma; benign cartilaginous islands are often seen microscopically at the periphery of chondrosarcoma. We attempted to detect these islands at the periphery of chondrosarcomas on MR and correlate them microscopically. Materials and methods: We examined our database for all patients with a chondrosarcoma of the long and flat bones between 1990 and 2007. Only those with a preoperative MR who underwent an en bloc resection were included, yielding 32 patients. We looked for low-signal islands surrounded by high (fat) signal on T1-weighted images, and high-signal islands surrounded by low signal on T2-weighted fat saturated images at the periphery of the main tumour mass. Microscopic correlation was performed in all cases. Results: On microscopy, there were 23 conventional chondrosarcomas, nine dedifferentiated. Peripheral islands surrounded by fat were detected on MR in 19 cases, corresponding to benign cartilage in 18 cases and to the benign scar of a needle biopsy tract in one. There were no peripheral islands detected radiographically or microscopically in 13 cases. Conclusion: Cartilaginous islands microscopically detected at the periphery of some chondrosarcomas are easily and reliably diagnosed on MR

  15. LIBVERSIONINGCOMPILER: An easy-to-use library for dynamic generation and invocation of multiple code versions

    Science.gov (United States)

    Cherubin, S.; Agosta, G.

    2018-01-01

    We present LIBVERSIONINGCOMPILER, a C++ library designed to support the dynamic generation of multiple versions of the same compute kernel in a HPC scenario. It can be used to provide continuous optimization, code specialization based on the input data or on workload changes, or otherwise to dynamically adjust the application, without the burden of a full dynamic compiler. The library supports multiple underlying compilers but specifically targets the LLVM framework. We also provide examples of use, showing the overhead of the library, and providing guidelines for its efficient use.

  16. Monitoring Attention in ADHD with an Easy-to-Use Electrophysiological Index

    Directory of Open Access Journals (Sweden)

    Goded Shahaf

    2018-02-01

    Full Text Available Attention deficit hyperactivity disorder (ADHD involves characteristic electroencephalographic (EEG activity. We developed a single-channel EEG marker for attention: the Brain Engagement Index (BEI’. In this study, we evaluated the use of BEI’ for distinguishing between ADHD patients and controls, and for monitoring the effect of pharmacological treatment on ADHD patients. The BEI’ values of 20 ADHD patients and 10 controls were measured using a 1-min auditory oddball paradigm and a continuous performance test (CPT task. We showed that CPT BEI’ is trait-specific and separates controls from ADHD patients. At the same time, oddball BEI’ is state-specific and identifies differences in attention level within the two groups of ADHD participants and controls. The oddball BEI’ also associates with response to treatment, after distinguishing between treatment effect and learning/time effect. The combined use of this marker with common computerized tests holds promise for research and clinical use in ADHD. Further work is required to confirm the results of the present study.

  17. Enchondroma vs. chondrosarcoma: A simple, easy-to-use, new magnetic resonance sign

    Energy Technology Data Exchange (ETDEWEB)

    Vanel, Daniel, E-mail: daniel.vanel@ior.it [Department of Research, Istituto Ortopedico Rizzoli, Bologna (Italy); Department of Pathology, Istituto Ortopedico Rizzoli, Bologna (Italy); Kreshak, Jennifer [Department of Pathology, Istituto Ortopedico Rizzoli, Bologna (Italy); Department of Orthopaedic Oncology, Istituto Ortopedico Rizzoli, Bologna (Italy); Larousserie, Frédérique [Department of Pathology, Istituto Ortopedico Rizzoli, Bologna (Italy); Université Paris Descartes, Sorbonne Paris Cité, Paris (France); Alberghini, Marco; Mirra, Joe [Department of Pathology, Istituto Ortopedico Rizzoli, Bologna (Italy); De Paolis, Massimiliano [Department of Orthopaedic Oncology, Istituto Ortopedico Rizzoli, Bologna (Italy); Picci, Piero [Department of Research, Istituto Ortopedico Rizzoli, Bologna (Italy)

    2013-12-01

    Introduction: There is no clear radiologic or pathologic agreement on the differences between enchondroma and conventional chondrosarcoma, which has huge therapeutic consequences. Microscopically, an enchondroma is composed of “islands of intramedullary hyaline cartilage surrounded by marrow fat”, and a chondrosarcoma a “diffuse cartilaginous replacement (invasion) of the marrow which leads to complete ‘trapping’ of host lamellar bone trabeculae.” The marrow around islands of cartilage should be detectable on magnetic resonance imaging (MR). Enchondroma may be the precursor of chondrosarcoma; benign cartilaginous islands are often seen microscopically at the periphery of chondrosarcoma. We attempted to detect these islands at the periphery of chondrosarcomas on MR and correlate them microscopically. Materials and methods: We examined our database for all patients with a chondrosarcoma of the long and flat bones between 1990 and 2007. Only those with a preoperative MR who underwent an en bloc resection were included, yielding 32 patients. We looked for low-signal islands surrounded by high (fat) signal on T1-weighted images, and high-signal islands surrounded by low signal on T2-weighted fat saturated images at the periphery of the main tumour mass. Microscopic correlation was performed in all cases. Results: On microscopy, there were 23 conventional chondrosarcomas, nine dedifferentiated. Peripheral islands surrounded by fat were detected on MR in 19 cases, corresponding to benign cartilage in 18 cases and to the benign scar of a needle biopsy tract in one. There were no peripheral islands detected radiographically or microscopically in 13 cases. Conclusion: Cartilaginous islands microscopically detected at the periphery of some chondrosarcomas are easily and reliably diagnosed on MR.

  18. Easy-to-use application programs for decay heat and delayed neutron calculations on personal computers

    Energy Technology Data Exchange (ETDEWEB)

    Oyamatsu, Kazuhiro [Nagoya Univ. (Japan)

    1998-03-01

    Application programs for personal computers are developed to calculate the decay heat power and delayed neutron activity from fission products. The main programs can be used in any computers from personal computers to main frames because their sources are written in Fortran. These programs have user friendly interfaces to be used easily not only for research activities but also for educational purposes. (author)

  19. Pteros: fast and easy to use open-source C++ library for molecular analysis.

    Science.gov (United States)

    Yesylevskyy, Semen O

    2012-07-15

    An open-source Pteros library for molecular modeling and analysis of molecular dynamics trajectories for C++ programming language is introduced. Pteros provides a number of routine analysis operations ranging from reading and writing trajectory files and geometry transformations to structural alignment and computation of nonbonded interaction energies. The library features asynchronous trajectory reading and parallel execution of several analysis routines, which greatly simplifies development of computationally intensive trajectory analysis algorithms. Pteros programming interface is very simple and intuitive while the source code is well documented and easily extendible. Pteros is available for free under open-source Artistic License from http://sourceforge.net/projects/pteros/. Copyright © 2012 Wiley Periodicals, Inc.

  20. An affordable and easy-to-use diagnostic method for keratoconus detection using a smartphone

    Science.gov (United States)

    Askarian, Behnam; Tabei, Fatemehsadat; Askarian, Amin; Chong, Jo Woon

    2018-02-01

    Recently, smartphones are used for disease diagnosis and healthcare. In this paper, we propose a novel affordable diagnostic method of detecting keratoconus using a smartphone. Keratoconus is usually detected in clinics with ophthalmic devices, which are large, expensive and not portable, and need to be operated by trained technicians. However, our proposed smartphone-based eye disease detection method is small, affordable, portable, and it can be operated by patients in a convenient way. The results show that the proposed keratoconus detection method detects severe, advanced, and moderate keratoconus with accuracies of 93%, 86%, 67%, respectively. Due to its convenience with these accuracies, the proposed keratoconus detection method is expected to be applied in detecting keratoconus at an earlier stage in an affordable way.

  1. Topology optimization using PETSc: An easy-to-use, fully parallel, open source topology optimization framework

    DEFF Research Database (Denmark)

    Aage, Niels; Andreassen, Erik; Lazarov, Boyan Stefanov

    2015-01-01

    This paper presents a flexible framework for parallel and easy-to-implement topology optimization using the Portable and Extendable Toolkit for Scientific Computing (PETSc). The presented framework is based on a standardized, and freely available library and in the published form it solves...

  2. Easy to use program “Simkine3” for simulating kinetic profiles of ...

    African Journals Online (AJOL)

    TLSoda which uses backward differentiation method is utilised to solve resulting ODEs and Downhill Simplex method is used to optimise the estimated rate constants in a robotic way. An online help file is developed using HelpScrible Demo to guide the users of Simkine3. The versatility of the software is demonstrated by ...

  3. SigrafW: An Easy-to-Use Program for Fitting Enzyme Kinetic Data

    Science.gov (United States)

    Leone, Francisco Assis; Baranauskas, Jose Augusto; Furriel, Rosa Prazeres Melo; Borin, Ivana Aparecida

    2005-01-01

    SigrafW is Windows-compatible software developed using the Microsoft[R] Visual Basic Studio program that uses the simplified Hill equation for fitting kinetic data from allosteric and Michaelian enzymes. SigrafW uses a modified Fibonacci search to calculate maximal velocity (V), the Hill coefficient (n), and the enzyme-substrate apparent…

  4. CrystalCMP: an easy-to-use tool for fast comparison of molecular packing

    Czech Academy of Sciences Publication Activity Database

    Rohlíček, Jan; Skořepová, E.; Babor, M.; Čejka, J.

    2016-01-01

    Roč. 49, č. 6 (2016), s. 2172-2183 ISSN 0021-8898 R&D Projects: GA ČR GA16-10035S Institutional support: RVO:68378271 Keywords : comparison * similarity packing * crystal structure * computer programs Subject RIV: JC - Computer Hardware ; Software Impact factor: 3.720, year: 2014

  5. Easy To Use Remote Sensing and GIS Analysis for Landslide Risk Assessment.

    Directory of Open Access Journals (Sweden)

    Hayder Dibs

    2017-12-01

    Full Text Available Many countries throughout the world suffered from the natural risks, they cause a large damage in property and loss in human lives, we cannot prevent the occurring of these hazards but, it is possible to reduce their affect in saving human lives and reducing the damage in properties. Several methodologies have been conducted to predict the suitable model for landslide assessment. The susceptibility maps of landslide hazard generated by combining the remote sensed data with the capability of GIS (geographic information system. We discussed different type of algorithms and factors for modeling the prediction of landslide risk assessment such as SVM (support vector machine, DT (decision tree, ANFIS (adaptive neural-fuzzy inference system, AHP (analytic hierarchy process, ANN (artificial neural network, probability frequency of landslides occurrence factors model and empirical model. The study evaluated various parameters that are responsible for landslide occurrence and the weighting for each parameter and its importance to probable of landslide activity. AHP method, Weights of evidence model, and back propagation method have been applied for weighting the factors.  We found that using ANN algorithm with more than ten factors will give high accuracy result especially if the validation performs by field surveys data.

  6. In Search of Easy-to-Use Methods for Calibrating ADCP's for Velocity and Discharge Measurements

    Science.gov (United States)

    Oberg, K.; ,

    2002-01-01

    A cost-effective procedure for calibrating acoustic Doppler current profilers (ADCP) in the field was presented. The advantages and disadvantages of various methods which are used for calibrating ADCP were discussed. The proposed method requires the use of differential global positioning system (DGPS) with sub-meter accuracy and standard software for collecting ADCP data. The method involves traversing a long (400-800 meter) course at a constant compass heading and speed, while collecting simultaneous DGPS and ADCP data.

  7. An Application-Independent Cryptography Model That Is Easy to Use for All Level Users

    Science.gov (United States)

    Gabrielson, Anthony J.

    2013-01-01

    Cryptography libraries are inflexible and difficult for developers to integrate with their applications. These difficulties are often encountered by applications, like PGP, which are non-intuitive for end-users and are often used improperly or not at all. This thesis discusses the negative impact of the current prevailing poor usability on…

  8. Developing a free and easy to use digital goal setting tool for busy mums

    Directory of Open Access Journals (Sweden)

    Babs Evans

    2015-09-01

    Using data, research and the expertise of commercial and charity partners was an effective way to design a digital product to support behavioural change. By understanding the target audience from the beginning and involving them in the planning stages, the organisations were able to develop a tool the users want with a strong focus on user experience.

  9. Development of an easy-to-use Spanish Health Literacy test.

    Science.gov (United States)

    Lee, Shoou-Yih D; Bender, Deborah E; Ruiz, Rafael E; Cho, Young Ik

    2006-08-01

    The study was intended to develop and validate a health literacy test, termed the Short Assessment of Health Literacy for Spanish-speaking Adults (SAHLSA), for the Spanish-speaking population. The design of SAHLSA was based on the Rapid Estimate of Adult Literacy in Medicine (REALM), known as the most easily administered tool for assessing health literacy in English. In addition to the word recognition test in REALM, SAHLSA incorporates a comprehension test using multiple-choice questions designed by an expert panel. Validation of SAHLSA involved testing and comparing the tool with other health literacy instruments in a sample of 201 Spanish-speaking and 202 English-speaking subjects recruited from the Ambulatory Care Center at UNC Health Care. With only the word recognition test, REALM could not differentiate the level of health literacy in Spanish. The SAHLSA significantly improved the differentiation. Item response theory analysis was performed to calibrate the SAHLSA and reduce the instrument to 50 items. The resulting instrument, SAHLSA-50, was correlated with the Test of Functional Health Literacy in Adults, another health literacy instrument, at r=0.65. The SAHLSA-50 score was significantly and positively associated with the physical health status of Spanish-speaking subjects (peducation. The instrument displayed good internal reliability (Cronbach's alpha=0.92) and test-retest reliability (Pearson's r=0.86). The new instrument, SAHLSA-50, has good reliability and validity. It could be used in the clinical or community setting to screen for low health literacy among Spanish speakers.

  10. MemBrain: An Easy-to-Use Online Webserver for Transmembrane Protein Structure Prediction

    Science.gov (United States)

    Yin, Xi; Yang, Jing; Xiao, Feng; Yang, Yang; Shen, Hong-Bin

    2018-03-01

    Membrane proteins are an important kind of proteins embedded in the membranes of cells and play crucial roles in living organisms, such as ion channels, transporters, receptors. Because it is difficult to determinate the membrane protein's structure by wet-lab experiments, accurate and fast amino acid sequence-based computational methods are highly desired. In this paper, we report an online prediction tool called MemBrain, whose input is the amino acid sequence. MemBrain consists of specialized modules for predicting transmembrane helices, residue-residue contacts and relative accessible surface area of α-helical membrane proteins. MemBrain achieves a prediction accuracy of 97.9% of A TMH, 87.1% of A P, 3.2 ± 3.0 of N-score, 3.1 ± 2.8 of C-score. MemBrain-Contact obtains 62%/64.1% prediction accuracy on training and independent dataset on top L/5 contact prediction, respectively. And MemBrain-Rasa achieves Pearson correlation coefficient of 0.733 and its mean absolute error of 13.593. These prediction results provide valuable hints for revealing the structure and function of membrane proteins. MemBrain web server is free for academic use and available at www.csbio.sjtu.edu.cn/bioinf/MemBrain/. [Figure not available: see fulltext.

  11. Easy to use plastic optical fiber-based biosensor for detection of butanal.

    Directory of Open Access Journals (Sweden)

    Nunzio Cennamo

    Full Text Available The final goal of this work is to achieve a selective detection of butanal by the realization of a simple, small-size and low cost experimental approach. To this end, a porcine odorant-binding protein was used in connection with surface plasmon resonance transduction in a plastic optical fiber tool for the selective detection of butanal by a competitive assay. This allows to reduce the cost and the size of the sensing device and it offers the possibility to design a "Lab-on-a-chip" platform. The obtained results showed that this system approach is able to selectively detect the presence of butanal in the concentration range from 20 μM to 1000 μM.

  12. Online Programs to Stop Sexual Harassment: Easy to Use but Not Always Enough

    Science.gov (United States)

    June, Audrey Williams

    2009-01-01

    A college's first line of defense against employees' making insinuating remarks, unwanted sexual advances, or requests for sexual favors is often about an hour of online sensitivity training. Some people, however, wonder if that line is strong enough. According to a 2006 survey of undergraduate students by the American Association of University…

  13. Rocker: Open source, easy-to-use tool for AUC and enrichment calculations and ROC visualization.

    Science.gov (United States)

    Lätti, Sakari; Niinivehmas, Sanna; Pentikäinen, Olli T

    2016-01-01

    Receiver operating characteristics (ROC) curve with the calculation of area under curve (AUC) is a useful tool to evaluate the performance of biomedical and chemoinformatics data. For example, in virtual drug screening ROC curves are very often used to visualize the efficiency of the used application to separate active ligands from inactive molecules. Unfortunately, most of the available tools for ROC analysis are implemented into commercially available software packages, or are plugins in statistical software, which are not always the easiest to use. Here, we present Rocker, a simple ROC curve visualization tool that can be used for the generation of publication quality images. Rocker also includes an automatic calculation of the AUC for the ROC curve and Boltzmann-enhanced discrimination of ROC (BEDROC). Furthermore, in virtual screening campaigns it is often important to understand the early enrichment of active ligand identification, for this Rocker offers automated calculation routine. To enable further development of Rocker, it is freely available (MIT-GPL license) for use and modifications from our web-site (http://www.jyu.fi/rocker).

  14. Scipion web tools: Easy to use cryo-EM image processing over the web.

    Science.gov (United States)

    Conesa Mingo, Pablo; Gutierrez, José; Quintana, Adrián; de la Rosa Trevín, José Miguel; Zaldívar-Peraza, Airén; Cuenca Alba, Jesús; Kazemi, Mohsen; Vargas, Javier; Del Cano, Laura; Segura, Joan; Sorzano, Carlos Oscar S; Carazo, Jose María

    2018-01-01

    Macromolecular structural determination by Electron Microscopy under cryogenic conditions is revolutionizing the field of structural biology, interesting a large community of potential users. Still, the path from raw images to density maps is complex, and sophisticated image processing suites are required in this process, often demanding the installation and understanding of different software packages. Here, we present Scipion Web Tools, a web-based set of tools/workflows derived from the Scipion image processing framework, specially tailored to nonexpert users in need of very precise answers at several key stages of the structural elucidation process. © 2017 The Protein Society.

  15. A powerful, yet easy to use, computerized analysis of competitive protein binding and radioimmunoassay data

    International Nuclear Information System (INIS)

    English, J.E.

    1981-01-01

    A computerized method has been developed and tested for the automatic computation of data obtained from competitive radio-binding assays, that is easily used by computer and non-computer oriented individuals. The program requires a series of only eleven parameter lines coded from the assay protocol, followed by the data exactly as it is produced from a standard sample counter. From the set of parameters the program is able to find standard curves at scattered locations through an assay, check their 'log dose-logit response' least squares linear regression equations statistically for homogeneity of slopes and elevations, pool the standard curves and check the pooled least squares linear regression equation statistically for linearity and non-linearity. The results of the pooled standard curve is presented graphically and in tabular form. Using the linear equation for the pooled standard curves, the concentration for each unknown sample is predicted with its corresponding 95% confidence interval and presented in a table of unknowns. Also provided in the table of unknowns is a mean and standard error of the mean for all biological replicates, including footnote flags to warn the user when an unknown concentration: (i) is outside the 0-100% bound range; (ii) is estimated from a range outside that covered by the standards; or (iii) was estimated from the unusable tail regions of the standard curve. (Auth.)

  16. SafeSlinger: An Easy-to-use and Secure Approach for Human Trust Establishment

    Science.gov (United States)

    2012-03-12

    headset. NFC is not yet widely deployed, and such communication does not scale to multiple devices. As a consequence, we use Internet-based...Keysigning Party HOWTO. http://cryptnet.net/fdp/crypto/ keysigning party/en/keysigning party.html, Jan. 2008. [5] Bump technologies . http://bu.mp/. [6...relationship. http://www.washingtonpost.com/business/ technology /2011/12/15/gIQAHNffwO story.html, December 2011. [34] Christopher Soghoian and Sid

  17. Assessment of SDN technology for an easy-to-use VPN service

    NARCIS (Netherlands)

    Pol, R. van der; Gijsen, B.M.M.; Zuraniewski, P.; Romão, D.F.C.; Kaat, M.

    2016-01-01

    This paper describes how state-of-the-art SDN technology can be used to create and validate a user configurable, on-demand VPN service. In the Community Connection (CoCo) project an architecture for the VPN service was designed and a prototype was developed based on the OpenFlow protocol and the

  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. 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

  20. 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

  1. 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.

  2. 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.

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

    Science.gov (United States)

    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.

  4. 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

  5. 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.

  6. High-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array

    Science.gov (United States)

    Guss, Paul; Rabin, Michael; Croce, Mark; Hoteling, Nathan; Schwellenbach, David; Kruschwitz, Craig; Mocko, Veronika; Mukhopadhyay, Sanjoy

    2017-09-01

    We demonstrate very high-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor (TES) array. The readout circuit consists of superconducting microwave resonators coupled to radio frequency superconducting-quantum-interference devices (RF-SQUIDs) and transduces changes in input current to changes in phase of a microwave signal. We used a flux-ramp modulation to linearize the response and avoid low-frequency noise. The result is a very high-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array. We performed and validated a small-scale demonstration and test of all the components of our concept system, which encompassed microcalorimetry, microwave multiplexing, RF-SQUIDs, and software-defined radio (SDR). We shall display data we acquired in the first simultaneous combination of all key innovations in a 4-pixel demonstration, including microcalorimetry, microwave multiplexing, RF-SQUIDs, and SDR. We present the energy spectrum of a gadolinium-153 (153Gd) source we measured using our 4-pixel TES array and the RF-SQUID multiplexer. For each pixel, one can observe the two 97.4 and 103.2 keV photopeaks. We measured the 153Gd photon source with an achieved energy resolution of 70 eV, full width half maximum (FWHM) at 100 keV, and an equivalent readout system noise of 90 pA/pHz at the TES. This demonstration establishes a path for the readout of cryogenic x-ray and gamma ray sensor arrays with more elements and spectral resolving powers. We believe this project has improved capabilities and substantively advanced the science useful for missions such as nuclear forensics, emergency response, and treaty verification through the explored TES developments.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under

  15. 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.

  16. 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

  17. 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

  18. 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...

  19. 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...

  20. 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

  1. 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.

  2. High resolution gas volume change sensor

    International Nuclear Information System (INIS)

    Dirckx, Joris J. J.; Aernouts, Jef E. F.; Aerts, Johan R. M.

    2007-01-01

    Changes of gas quantity in a system can be measured either by measuring pressure changes or by measuring volume changes. As sensitive pressure sensors are readily available, pressure change is the commonly used technique. In many physiologic systems, however, buildup of pressure influences the gas exchange mechanisms, thus changing the gas quantity change rate. If one wants to study the gas flow in or out of a biological gas pocket, measurements need to be done at constant pressure. In this article we present a highly sensitive sensor for quantitative measurements of gas volume change at constant pressure. The sensor is based on optical detection of the movement of a droplet of fluid enclosed in a capillary. The device is easy to use and delivers gas volume data at a rate of more than 15 measurements/s and a resolution better than 0.06 μl. At the onset of a gas quantity change the sensor shows a small pressure artifact of less than 15 Pa, and at constant change rates the pressure artifact is smaller than 10 Pa or 0.01% of ambient pressure

  3. Inductive Non-Contact Position Sensor

    Science.gov (United States)

    Youngquist, Robert; Garcia, Alyssa; Simmons, Stephen

    2010-01-01

    Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter's windows. In this hardware, a mirror is translated such that its position corresponds to the defect's depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is preferable because the mirror is internal to the optical system and thus accessible. Based on requirements supplied by the window inspectors, the depth of the defects needs to be measured over a range of 200 microns with a resolution of about 100 nm and an accuracy of about 400 nm. These same requirements then apply to measuring the position of the mirror, and in addition, since this is a scanning system, a response time of about 10 ms is needed. A market search was conducted and no sensor that met these requirements that also fit into the available housing volume (less than one cubic inch) was found, so a novel sensor configuration was constructed to meet the requirements. This new sensor generates a nearly linearly varying magnetic field over a small region of space, which can easily be sampled, resulting in a voltage proportional to position. Experiments were done with a range of inductor values, drive voltages, drive frequencies, and inductor shapes. A rough mathematical model was developed for the device that, in most aspects, describes how it operates and what electrical parameters should be chosen for best performance. The final configuration met all the requirements, yielding a small rugged sensor that was easy to use and had nanometer resolution over more than the 200-micron range required. The inductive position sensor is a compact device (potentially as small as 2 cubic centimeters), which offers nanometer-position resolution over a demonstrated range of nearly 1 mm. One of its advantages is the simplicity of its electrical design. Also, the sensor resolution is nearly uniform across its operational range, which is in contrast to eddy current and

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. Magnetic characterization by SQUID and FMR of a biocompatible ferrofluid based on Fe3O4

    International Nuclear Information System (INIS)

    Gamarra, L F; Amaro Jr, E; Pontuschka, W M; Mamani, J B; Cornejo, D R; Oliveira, T R; Vieira, E D; Costa-Filho, A J

    2009-01-01

    Biocompatible superparamagnetic iron oxide nanoparticles of magnetite coated with dextran were magnetically characterized using the techniques of SQUID (superconducting quantum interference device) magnetometry and ferromagnetic resonance (FMR). The SQUID magnetometry characterization was performed by isothermal measurements under applied magnetic field using the methods of zero-field-cooling (ZFC) and field-cooling (FC). The magnetic behavior of the nanoparticles indicated their superparamagnetic nature and it was assumed that they consisted exclusively of monodomains. The transition to a blocked state was observed at the temperature T B = (43 ± 1) K for frozen ferrofluid and at (52 ± 1) K for the lyophilized ferrofluid samples. The FMR analysis showed that the derivative peak-to-peak linewidth (ΔH PP ), gyromagnetic factor (g), number of spins (N S ), and spin-spin relaxation time (T 2 ) were strongly dependent on both temperature and super-exchange interaction. This information is important for possible nanotechnological applications, mainly those which are strongly dependent on the magnetic parameters.

  13. Lateral line analogue aids vision in successful predator evasion for the brief squid, Lolliguncula brevis.

    Science.gov (United States)

    York, Carly A; Bartol, Ian K

    2014-07-15

    Cephalopods have visual and mechanoreception systems that may be employed to sense and respond to an approaching predator. While vision presumably plays the dominant role, the importance of the lateral line analogue for predator evasion has not been examined in cephalopods. To test the respective roles of vision and the lateral line analogue, brief squid, Lolliguncula brevis, were observed in the presence of summer flounder, Paralichthys dentatus, under light and dark conditions with their lateral line analogue intact and ablated. Hair cell ablation was achieved through a pharmacological technique used for the first time on a cephalopod. The proportion of predator-prey interactions survived was significantly higher in the light non-ablated and light ablated groups compared with the dark ablated group. The mean number of interactions survived varied across treatment groups with the light non-ablated group having significantly more success than the light ablated, dark non-ablated and dark ablated groups. These findings demonstrate that although vision is the primary sense, the lateral line analogue also contributes to predator evasion in squid. © 2014. Published by The Company of Biologists Ltd.

  14. Compensation for longitudinal chromatic aberration in the eye of the firefly squid, Watasenia scintillans.

    Science.gov (United States)

    Kröger, Ronald H H; Gislén, Anna

    2004-01-01

    The camera eyes of fishes and cephalopods have come forth by convergent evolution. In a variety of vertebrates capable of color vision, longitudinal chromatic aberration (LCA) of the optical system is corrected for by the exactly tuned longitudinal spherical aberration (LSA) of the crystalline lens. The LSA leads to multiple focal lengths, such that several wavelengths can be focused on the retina. We investigated whether that is also the case in the firefly squid (Watasenia scintillans), a cephalopod species that is likely to have color vision. It was found that the lens of W. scintillans is virtually free of LSA and uncorrected for LCA. However, the eye does not suffer from LCA because of a banked retina. Photoreceptors sensitive to short and long wavelengths are located at appropriate distances from the lens, such that they receive well-focused images. Such a design is an excellent solution for the firefly squid because a large area of the retina is monochromatically organized and it allows for double use of the surface area in the dichromatically organized part of the retina. However, it is not a universal solution since compensation for LCA by a banked retina requires that eye size and/or spectral separation between photopigments is small.

  15. Reproductive behavior in the squid Sepioteuthis australis from South Australia: interactions on the spawning grounds.

    Science.gov (United States)

    Jantzen, Troy M; Havenhand, Jon N

    2003-06-01

    Squid behavior is synonymous with distinctive body patterns, postures, and movements that constitute a complex visual communication system. These communications are particularly obvious during reproduction. They are important for sexual selection and have been identified as a potential means of species differentiation. Here we present a detailed account of copulation, mating, and egg deposition behaviors from in situ observations of the squid Sepioteuthis australis from South Australia. We identified four mating types from 85 separate mating attempts: "Male-upturned mating" (64% of mating attempts); "Sneaker mating" (33%); "Male-parallel" (2%); and "Head-to-head" (1%). Intervals between successive egg deposition behaviors were clearly bimodal, with modes at 2.5 s and 70.0 s. Ninety-three percent of egg capsules contained 3 or 4 eggs (mean = 3.54), and each egg cluster contained between 218 and 1922 egg capsules (mean = 893.9). The reproductive behavior of S. australis from South Australia was different from that described for other cephalopod species. More importantly, comparison between these results and those for other populations of S. australis suggests that behavior may differ from one population to another.

  16. Biosynthesis of fatty acids and cholesterol in squid giant nerve fiber

    International Nuclear Information System (INIS)

    Tanaka, T.; Kishimoto, Y.; Gould, R.M.

    1987-01-01

    The giant nerve fiber of squid 3 (loligo pealel) was incubated with [1- 14 C]acetate and ( 3 H)myristate. Fifty-five percent of the radioactivity incorporated from acetate was recovered in fatty acid methyl esters (FAME). The FAME was fractionated by AgNO 3 -impregnated TLC plate; and 52%, 31%, 0.3%, 5%, and 11% of the radioactivity was recovered in spots associated with saturated, monoenes, dienes, trienes, and polyenes, respectively. The saturated FAME was further fractionated by reverse-phase HPLC; and 4, 47, 1, and 48% of the radioactivity was recovered in 14:0, 16:0, 17:0, and 18:0, respectively. Most radioactivity from polyenes migrated to the spot containing saturated FAME, after catalytical hydrogenation. Cholesterol was isolated and converted to dibromoderivative and the derivative was recrystallized. No radioactivity was found in purified dibromocholesterol. Nearly all radioactivity from myristate-labeled tissue was recovered in saturated FAME. Reverse-phase HPLC showed that 71%, 25%, and 3% of radioactivity was associated with 14:0, 16:0, and 18:0, respectively. These results indicate that the squid giant nerve fibers can synthesize fatty acids by de novo and also by chain elongation and desaturation, though at a slower rate

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

    Science.gov (United States)

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

    2004-01-01

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

  18. Squids, snakes, and polarimeters: A new technique for measuring the magnetic moments of polarized beams

    International Nuclear Information System (INIS)

    Cameron, P.R.; Luccio, A.U.; Shea, T.J.; Tsoupas, N.; Goldberg, D.A.

    1997-01-01

    Effective polarimetry at high energies in hadron and lepton synchrotrons has been a long-standing and difficult problem. In synchrotrons with polarized beams it is possible to cause the direction of the polarization vector of a given bunch to alternate at a frequency which is some subharmonic of the rotation frequency. This can result in the presence of lines in the beam spectrum which are due only to the magnetic moment of the beam and which are well removed from the various lines due to the charge of the beam. The magnitude of these lines can be calculated from first principles. They are many orders of magnitude weaker than the Schottky signals. Measurement of the magnitude of one of these lines would be an absolute measurement of beam polarization. For measuring magnetic field, the Superconducting Quantum Interference Device, or squid, is about five orders of magnitude more sensitive than any other transducer. Using a squid, such a measurement might be accomplished with the proper combination of shielding, pickup loop design, and filtering. The resulting instrument would be fast, non-destructive, and comparatively cheap. In addition, techniques developed in the creation of such an instrument could be used to measure the Schottky spectrum in unprecedented detail. We present specifics of a polarimeter design for the Relativistic Heavy Ion Collider (RHIC) and briefly discuss the possibility of using this technique to measure polarization at high-energy electron machines like LEP and HERA. copyright 1997 American Institute of Physics

  19. The effect of sampling methods on the apparent constituents of ink from the squid Sepioteuthis australis.

    Science.gov (United States)

    Madaras, F; Gerber, J P; Peddie, F; Kokkinn, M J

    2010-11-01

    Results of experiments conducted on ink recovered from the squid Sepioteuthis australis indicate that there is no epinephrine or protein naturally present in the ink as it would be ejected in vivo. Protein content was effectively zero when ink was syringed from the duct end of the ink sac of freshly killed animals. By contrast, there were proteins in samples collected from dead specimens where ink was collected by a stripping method. From these samples, a single large molecular weight protein was identified as having tyrosinase activity. Digestion of syringed ink did not yield signs of melanin-bound proteins. Analysis of supernatants after centrifugation of squid ink consistently revealed the presence of DOPA, dopamine, and taurine, whereas epinephrine and nor-epinephrine were recorded from what was believed to be contaminated ink. Histological investigations of the ink sac revealed a compartmentalised glandular structure distal to the duct end. Closer observation of the glandular tissue showed that compartments increased in size as they matured and moved further into the lumen. It was concluded that the presence of epinephrine and tyrosinase (or a related protein) in the ink of S. australis could be attributed to rupturing of basal glandular compartments or contamination from other sources during the extraction process.

  20. Identifying the cellular mechanisms of symbiont-induced epithelial morphogenesis in the squid-Vibrio association.

    Science.gov (United States)

    Koropatnick, Tanya; Goodson, Michael S; Heath-Heckman, Elizabeth A C; McFall-Ngai, Margaret

    2014-02-01

    The symbiotic association between the Hawaiian bobtail squid Euprymna scolopes and the luminous marine bacterium Vibrio fischeri provides a unique opportunity to study epithelial morphogenesis. Shortly after hatching, the squid host harvests bacteria from the seawater using currents created by two elaborate fields of ciliated epithelia on the surface of the juvenile light organ. After light organ colonization, the symbiont population signals the gradual loss of the ciliated epithelia through apoptosis of the cells, which culminates in the complete regression of these tissues. Whereas aspects of this process have been studied at the morphological, biochemical, and molecular levels, no in-depth analysis of the cellular events has been reported. Here we describe the cellular structure of the epithelial field and present evidence that the symbiosis-induced regression occurs in two steps. Using confocal microscopic analyses, we observed an initial epithelial remodeling, which serves to disable the function of the harvesting apparatus, followed by a protracted regression involving actin rearrangements and epithelial cell extrusion. We identified a metal-dependent gelatinolytic activity in the symbiont-induced morphogenic epithelial fields, suggesting the involvement of Zn-dependent matrix metalloproteinase(s) (MMP) in light organ morphogenesis. These data show that the bacterial symbionts not only induce apoptosis of the field, but also change the form, function, and biochemistry of the cells as part of the morphogenic program.

  1. Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes.

    Science.gov (United States)

    Boettcher, K J; Ruby, E G

    1990-07-01

    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 molecule involved in the positive transcriptional regulation of the V. fischeri lux operon. Such an absence of visible light production outside of the symbiotic association has not been previously reported among light organ symbionts of this or any other species of luminous bacteria. Levels of luminescence approaching those of the E. scolopes bacteria in the intact association can be restored by the addition of exogenous autoinducer to bacteria in laboratory culture and are affected by the presence of cyclic AMP. We conclude that some condition(s) specific to the internal environment of the light organ is necessary for maximal autoinduction of luminescence in the symbionts of this squid-bacterial association.

  2. A Transient Exposure to Symbiosis-Competent Bacteria Induces Light Organ Morphogenesis in the Host Squid.

    Science.gov (United States)

    Doino, J A; McFall-Ngai, M J

    1995-12-01

    Recent studies of the symbiotic association between the Hawaiian sepiolid squid Euprymna scolopes and the luminous bacterium Vibrio fischeri have shown that colonization of juvenile squid with symbiosis-competent bacteria induces morphogenetic changes of the light organ. These changes occur over a 4-day period and include cell death and tissue regression of the external ciliated epithelium. In the absence of bacterial colonization, morphogenesis does not occur. To determine whether the bacteria must be present throughout the morphogenetic process, we used the antibiotic chloramphenicol to clear the light organ of bacteria at various times during the initial colonization. We provide evidence in this study that a transient, 12-hour exposure to symbiosis-competent bacteria is necessary and sufficient to induce tissue regression in the light organ over the next several days. Further, we show that successful entrance into the light organ is necessary to induce morphogenesis, suggesting that induction results from bacterial interaction with internal crypt cells and not with the external ciliated epithelium. Finally, no difference in development was observed when the light organ was colonized by a mutant strain of V. fischeri that did not produce autoinducer, a potential light organ morphogen.

  3. Detection of fine magnetic particles coated on a thread using an HTS-SQUID

    International Nuclear Information System (INIS)

    Kawagishi, K.; Itozaki, H.; Kondo, T.; Komori, K.; Koetitz, R.

    2004-01-01

    Polymer-coated magnetic particles, which contain superparamagnetic ferrite nanoparticles, were attached to a nylon thread of 0.35 mm in diameter and were detected by an HTS-SQUID. The length of the sample attached into the thread was within 3 mm and its interval was 30 mm. The particles were magnetized by a coil applied dc field or by a magnet of 1.4 T. The thread ran 2 mm under the SQUID with 20-100 mm/s of the rate. Signals of magnetic beads were detected and the peak-to-peak amplitude of the signals was directly proportional to the applied field and the weight of the magnetic particles. Obtained peak-to-peak amplitude for 20 ng of magnetite particles was 350 pT at 0.25 mT of applied dc field with noise of 18 pT, and estimated detection limit was 10 ng. S/N ratio was improved by the remanence measurement using the magnet and 5.8 ng of detection limit was obtained. This measurement has been proved to be promising for the continuous analysis of ultra dilute DNA solution

  4. YBCO nanoSQUIDs applied to the investigation of small spin systems

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Perez, Maria Jose; Schwarz, Tobias; Woelbing, Roman; Mueller, Benedikt; Kleiner, Reinhold; Koelle, Dieter [Physikalisches Institut and Center for Collective Quantum Phenomena in LISA" +, Universitaet Tuebingen (Germany); Reiche, Christopher F.; Muehl, Thomas; Buechner, Bernd [Leibniz Institute for Solid State and Materials Research IFW Dresden (Germany); Sese, Javier [Instituto de Nanociencia de Aragon and Advanced Microscopy Laboratory, Zaragoza (Spain)

    2015-07-01

    We present the realization of ultra-sensitive YBCO nanoSQUIDs based on submicron grain boundary junctions patterned by focused ion beam milling. White flux noise down to ∝ 50nΦ{sub 0}/Hz{sup 1/2} has been achieved, yielding spin sensitivities of down to a few μ{sub B}/Hz{sup 1/2} at T=4.2 K. Moreover, we demonstrate that magnetic fields up to the tesla range can be applied, fulfilling a fundamental condition for the study of small spin systems. As a proof-of-principle we present the successful deposition of a Fe-filled carbon nanotube (∝ 40 nm in diameter and ∝ 14 μm in length) and an individual Co nanopillar (base diameter of ∝ 50 nm and height ∝ 10 nm) close to the nanoSQUID loop. We show that sub-micrometric control over the particle position lead to large magnetic coupling factors between the nano-loop and the spin system. Together with the possibility of applying large magnetic fields, the latter has allowed us to directly observe the magnetization reversal of these spin systems at different temperatures.

  5. Interference characterisation of a commercial Joule-Thomson cooler to be used in a SQUID-based heart monitor

    NARCIS (Netherlands)

    Bangma, M.R.; Bangma, M.R.; Rijpma, A.P.; de Vries, E.; Reincke, H.A.; Holland, Herman J.; ter Brake, Hermanus J.M.; Rogalla, Horst

    2001-01-01

    At the University of Twente, a foetal heart monitor based on a high-TC SQUID magnetometer system is under development. The purpose of this system is to measure a foetal heart signal in a clinical environment. For cooling a first demonstrator version, a closed-cycle Joule–Thomson cooler from APD

  6. Interference characterisation of a commercial Joule-Thomson cooler to be used in a SQUID-based foetal heart monitor

    NARCIS (Netherlands)

    Bangma, M.R.; Rijpma, A.P.; Vries, de E.; Reincke, H.A.; Holland, H.J.; Brake, ter H.J.M.; Rogalla, H.

    2001-01-01

    At the University of Twente, a fetal heart monitor based on a high-TC SQUID magnetometer system is under development. The purpose of this system is to measure a fetal heart signal in a clin. environment. For cooling a first demonstrator version, a closed-cycle Joule-Thomson cooler from APD

  7. 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.

  8. Projected near-future CO2 levels increase activity and alter defensive behaviours in the tropical squid Idiosepius pygmaeus

    Directory of Open Access Journals (Sweden)

    Blake L. Spady

    2014-10-01

    Full Text Available Carbon dioxide (CO2 levels projected to occur in the oceans by the end of this century cause a range of behavioural effects in fish, but whether other highly active marine organisms, such as cephalopods, are similarly affected is unknown. We tested the effects of projected future CO2 levels (626 and 956 µatm on the behaviour of male two-toned pygmy squid, Idiosepius pygmaeus. Exposure to elevated CO2 increased the number of active individuals by 19–25% and increased movement (number of line-crosses by nearly 3 times compared to squid at present-day CO2. Squid vigilance and defensive behaviours were also altered by elevated CO2 with >80% of individuals choosing jet escape responses over defensive arm postures in response to a visual startle stimulus, compared with 50% choosing jet escape responses at control CO2. In addition, more escape responses were chosen over threat behaviours in body pattern displays at elevated CO2 and individuals were more than twice as likely to use ink as a defence strategy at 956 µatm CO2, compared with controls. Increased activity could lead to adverse effects on energy budgets as well as increasing visibility to predators. A tendency to respond to a stimulus with escape behaviours could increase survival, but may also be energetically costly and could potentially lead to more chases by predators compared with individuals that use defensive postures. These results demonstrate that projected future ocean acidification affects the behaviours of a tropical squid species.

  9. Y1Ba2Cu3O(7-delta) thin film dc SQUIDs (superconducting quantum interference device)

    Science.gov (United States)

    Racah, Daniel

    1991-03-01

    Direct current superconducting quantum interferometers (SQUIDs) based on HTSC thin films have been measured and characterized. The thin films used were of different quality: (1) Granular films on Sapphire substrates, prepared either by e-gun evaporation, by laser ablation or by MOCVD (metal oxide chemical vapor deposition), (2) Epitaxial films on MgO substrates. Modulations of the voltage on the SQUIDs as a function of the applied flux have been observed in a wide range of temperatures. The nature of the modulation was found to be strongly dependent on the morphology of the film and on its critical current. The SQUIDs based on granular films were relatively noisy, hysteretic and with a complicated V-phi shape. Those devices based on low quality (lowIc) granular films could be measured only at low temperatures (much lower than 77 K). While those of higher quality (granular films with high Ic) could be measured near to the superconductive transition. The SQUID based on high quality epitaxial film was measured near Tc and showed an anomalous, time dependent behavior.

  10. Commercial squids: characterization, assessment of potential health benefits/risks and discrimination based on mineral, lipid and vitamin E concentrations.

    Science.gov (United States)

    Torrinha, A; Gomes, F; Oliveira, M; Cruz, R; Mendes, E; Delerue-Matos, C; Casal, S; Morais, S

    2014-05-01

    The most consumed squid species worldwide were characterized regarding their concentrations of minerals, fatty acids, cholesterol and vitamin E. Interspecific comparisons were assessed among species and geographical origin. The health benefits derived from squid consumption were assessed based on daily minerals intake and on nutritional lipid quality indexes. Squids contribute significantly to daily intake of several macro (Na, K, Mg and P) and micronutrients (Cu, Zn and Ni). Despite their low fat concentration, they are rich in long-chain omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicosapentanoic (EPA) acids, with highly favorable ω-3/ω-6 ratios (from 5.7 to 17.7), reducing the significance of their high cholesterol concentration (140-549 mg/100g ww). Assessment of potential health risks based on minerals intake, non-carcinogenic and carcinogenic risks indicated that Loligo gahi (from Atlantic Ocean), Loligo opalescens (from Pacific Ocean) and Loligo duvaucelii (from Indic Ocean) should be eaten with moderation due to the high concentrations of Cu and/or Cd. Canonical discriminant analysis identified the major fatty acids (C14:0, C18:0, C18:1, C18:3ω-3, C20:4ω-6 and C22:5ω-6), P, K, Cu and vitamin E as chemical discriminators for the selected species. These elements and compounds exhibited the potential to prove authenticity of the commercially relevant squid species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Dynamics of d-wave YBa{sub 2}Cu{sub 3}O{sub 7-x} dc SQUIDs

    Energy Technology Data Exchange (ETDEWEB)

    Bauch, T [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden); Cedergren, K [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden); Johansson, J [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden); Rotoli, G [Dipartimento di Ingeneria Meccanica, Energetica e Gestionale, Universita of L' Aquila, Localita Moneluco, L' Aquila (Italy); Tafuri, F [Dipartimento Ingeneria dell' Informatione, INFM, Seconda Universita di Napoli, Aversa (Italy); Lombardi, F [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden)

    2007-02-15

    The predominant d-wave pairing symmetry in high temperature superconductors leads to an unconventional current-phase relation in Josephson junctions. This circumstance may induce new effects in the dynamics of dc SQUIDs. In this contribution we report on the measurements of the dependence of the SQUID Josephson current on the external magnetic field taken at very low temperatures, down to 20 mK. Different grain boundaries have been fabricated by using the biepitaxial and the bicrystal technique. Some of the effects which are induced by a nonsinusoidal current-phase relation can be clearly identified in the dynamics of the SQUIDs. The experimental data are also compared with theoretical simulations taking into account the inductance of the loop. The data show that, in specific conditions, a non-negligible inductance of the loop can induce effects similar to an unconventional current-phase relation, with a pronounced second harmonic sin(2{psi}) term. This fact has to be taken into account when designing d-wave SQUIDs for quantum circuitry.

  12. Reproductive system and the spermatophoric reaction of the mesopelagic squid Octopoteuthis sicula (Ruppell 1844) (Cephalopoda : Octopoteuthidae) from southern African waters

    NARCIS (Netherlands)

    Hoving, H. J. T.; Lipinski, M. R.; Videler, J. J.

    2008-01-01

    Reproductive features of the poorly known oceanic squid Octopoteuthis sicula are described and quantified to gain insight into the reproductive biology of the species. The data are based on 39 complete and partial specimens from southern African waters, collected between 1975 and 2005. The specimens

  13. Magnetic properties of Fe/ZnSe and Fe/GaAs heterostructures investigated by ferromagnetic resonance and SQUID measurements

    Czech Academy of Sciences Publication Activity Database

    Meckenstock, R.; Spodding, D.; Himmelbauer, K.; Krenn, H.; Doi, M.; Keune, W.; Frait, Zdeněk; Pelzl, J.

    2002-01-01

    Roč. 240, - (2002), s. 410-413 ISSN 0304-8853 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic resonance * squid * anisotropy-growth-induced * relaxation-magnetic Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.046, year: 2002

  14. Differential expression of the FMRF gene in adult and hatchling stellate ganglia of the squid Loligo pealei

    NARCIS (Netherlands)

    Burbach, J.P.H.; Grant, P.; Hellemons, A.J.C.G.; DeGiorgis, J.A.; Li, K.W.; Pant, H.C.

    2014-01-01

    The giant fiber system of the squid Loligo pealei mediates the escape response and is an important neurobiological model. Here, we identified an abundant transcript in the stellate ganglion (SG) that encodes a FMRFamide precursor, and characterized FMRFamide and FI/LRF-amide peptides. To determine

  15. Attention Sensor

    NARCIS (Netherlands)

    Börner, Dirk; Kalz, Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built

  16. Nuclear magnetic resonance with dc SQUID [Super-conducting QUantum Interference Device] preamplifiers

    International Nuclear Information System (INIS)

    Fan, N.Q.; Heaney, M.B.; Clark, J.; Newitt, D.; Wald, L.; Hahn, E.L.; Bierlecki, A.; Pines, A.

    1988-08-01

    Sensitive radio-frequency (rf) amplifiers based on dc Superconducting QUantum Interface Devices (SQUIDS) are available for frequencies up to 200 MHz. At 4.2 K, the gain and noise temperature of a typical tuned amplifier are 18.6 +- 0.5 dB and 1.7 +- 0.5 K at 93 MHz. These amplifiers are being applied to a series of novel experiments on nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR). The high sensitivity of these amplifiers was demonstrated in the observation of ''nuclear spin noise'', the emission of photons by 35 Cl nuclei in a state of zero polarization. In the more conventional experiments in which one applies a large rf pulse to the spins, a Q-spoiler, consisting of a series array of Josephson junctions, is used to reduce the Q of the input circuit to a very low value during the pulse. The Q-spoiler enables the circuit to recover quickly after the pulse, and has been used in an NQR experiment to achieve a sensitivity of about 2 /times/ 10 16 nuclear Bohr magnetons in a single free precession signal with a bandwidth of 10 kHz. In a third experiment, a sample containing 35 Cl nuclei was placed in a capacitor and the signal detected electrically using a tuned SQUID amplifier and Q-spoiler. In this way, the electrical polarization induced by the precessing Cl nuclear quadrupole moments was detected: this is the inverse of the Stark effect in NQR. Two experiments involving NMR have been carried out. In the first, the 30 MHz resonance in 119 Sn nuclei is detected with a tuned amplifier and Q-spoiler, and a single pulse resolution of 10 18 nuclear Bohr magnetons in a bandwidth of 25 kHz has been achieved. For the second, a low frequency NMR system has been developed that uses an untuned input circuit coupled to the SQUID. The resonance in 195 Pt nuclei has been observed at 55 kHz in a field of 60 gauss. 23 refs., 11 figs

  17. SQUID-magnetometry on Fe monolayers on GaAs(001) in UHV

    Energy Technology Data Exchange (ETDEWEB)

    Kebe, T

    2006-12-11

    This thesis deals with the characterization of the growth and of the magnetic properties of ultrathin Fe films on GaAs(001). In particular, a scanning SQUID (superconducting quantum interference device) magnetometer was used in ultrahigh vacuum (UHV), whose performance has been improved within the scope of this thesis. By probing the magnetic stray field of a magnetized film, the absolute remanent magnetization can be determined with submonolayer sensitivity. In the context of this thesis the magnetic stray field has been calculated analytically. The combined use of SQUID and ferromagnetic resonance (FMR) on the same film in UHV allows for the independent determination of the magnetization and the magnetic anisotropy constants as a function of temperature, film thickness, topography of the substrate and oxygen exposure. The results of this thesis are: 1. The thickness dependent remanent magnetization from 2 to 20 monolayer (ML) Fe on GaAs(001) without cap layer was measured as a function of temperature. 2. The continuous in-plane reorientation of the magnetization (from [1 1 0] to [1 0 0]) of Fe films with increasing film thickness was observed using the scanning SQUID technique and showed good agreement with FMR measurements. 3. The influence of controlled oxygen exposure on the remanent magnetization and the magnetic anisotropy constants of 5 to 16 ML Fe was investigated. A faster reduction of the magnetization is found for the thinner Fe films when the volume of the Fe oxide is taken into consideration. At low oxygen exposure (<10 Langmuir), the perpendicular uniaxial anisotropy constant K{sub 2} {sub perpendicular} {sub to} is reduced by about 40% whereas other anisotropy contributions remain virtually unchanged. In addition, structural investigations using IV-LEED during the oxygen exposure were carried out. 4. An 8.6 ML Fe/GaAs(001) film which was exposed to 25000 L O{sub 2} exhibits a spontaneous magnetization perpendicular to the film plane at low

  18. NASA SensorWeb and OGC Standards for Disaster Management

    Science.gov (United States)

    Mandl, Dan

    2010-01-01

    I. Goal: Enable user to cost-effectively find and create customized data products to help manage disasters; a) On-demand; b) Low cost and non-specialized tools such as Google Earth and browsers; c) Access via open network but with sufficient security. II. Use standards to interface various sensors and resultant data: a) Wrap sensors in Open Geospatial Consortium (OGC) standards; b) Wrap data processing algorithms and servers with OGC standards c) Use standardized workflows to orchestrate and script the creation of these data; products. III. Target Web 2.0 mass market: a) Make it simple and easy to use; b) Leverage new capabilities and tools that are emerging; c) Improve speed and responsiveness.

  19. The Design of Tools for Sketching Sensor-Based Interaction

    DEFF Research Database (Denmark)

    Brynskov, Martin; Lunding, Rasmus; Vestergaard, Lasse Steenbock

    2012-01-01

    In this paper we motivate, present, and give an initial evaluation of DUL Radio, a small wireless toolkit for sketching sensor-based interaction. In the motivation, we discuss the purpose of this specific platform, which aims to balance ease-of-use (learning, setup, initialization), size, speed......, flexibility and cost, aimed at wearable and ultra-mobile prototyping where fast reaction is needed (e.g. in controlling sound), and we discuss the general issues facing this category of embodied interaction design tools. We then present the platform in more detail, both regarding hard- ware and software....... In the brief evaluation, we present our initial experiences with the platform both in design projects and in teaching. We conclude that DUL Radio does seem to be a relatively easy-to-use tool for sketching sensor-based interaction compared to other solutions, but that there are many ways to improve it. Target...

  20. Inertial Sensor-Based Gait Recognition: A Review

    Science.gov (United States)

    Sprager, Sebastijan; Juric, Matjaz B.

    2015-01-01

    With the recent development of microelectromechanical systems (MEMS), inertial sensors have become widely used in the research of wearable gait analysis due to several factors, such as being easy-to-use and low-cost. Considering the fact that each individual has a unique way of walking, inertial sensors can be applied to the problem of gait recognition where assessed gait can be interpreted as a biometric trait. Thus, inertial sensor-based gait recognition has a great potential to play an important role in many security-related applications. Since inertial sensors are included in smart devices that are nowadays present at every step, inertial sensor-based gait recognition has become very attractive and emerging field of research that has provided many interesting discoveries recently. This paper provides a thorough and systematic review of current state-of-the-art in this field of research. Review procedure has revealed that the latest advanced inertial sensor-based gait recognition approaches are able to sufficiently recognise the users when relying on inertial data obtained during gait by single commercially available smart device in controlled circumstances, including fixed placement and small variations in gait. Furthermore, these approaches have also revealed considerable breakthrough by realistic use in uncontrolled circumstances, showing great potential for their further development and wide applicability. PMID:26340634

  1. Development of contaminant detection system based on ultra-low field SQUID-NMR/MRI

    International Nuclear Information System (INIS)

    Tsunaki, S; Yamamoto, M; Hatta, J; Hatsukade, Y; Tanaka, S

    2014-01-01

    We have developed an ultra-low field (ULF) NMR/MRI system using an HTS-rf-SQUID and evaluated performance of the system as a contaminant detection system for foods and drinks. In this work, we measured 1D MRIs from water samples with or without various contaminants, such as aluminum and glass balls using the system. In the 1D MRIs, changes of the MRI spectra were detected, corresponding to positions of the contaminants. We measured 2D MRIs from food samples with and without a hole. In the 2D MRIs, the hole position in the sample was well visualized. These results show that the feasibility of the system to detect and localize contaminants in foods and drinks.

  2. Customizing Properties of β-Chitin in Squid Pen (Gladius by Chemical Treatments

    Directory of Open Access Journals (Sweden)

    Alessandro Ianiro

    2014-12-01

    Full Text Available The squid pen (gladius from the Loligo vulgaris was used for preparation of β-chitin materials characterized by different chemical, micro- and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The β-chitin materials obtained by alkaline treatment showed porosity, wettability and swelling that are a function of the duration of the treatment. Microscopic, spectroscopic and synchrotron X-ray diffraction techniques showed that the chemical environment of the N-acetyl groups of the β-chitin chains changes after the thermal alkaline treatment. As a consequence, the crystalline packing of the β-chitin is modified, due to the intercalation of water molecules between β-chitin sheets. Potential applications of these β-chitin materials range from the nanotechnology to the regenerative medicine. The use of gladii, which are waste products of the fishing industry, has also important environmental implications.

  3. Concentrations of biogenic amines in fish, squid and octopus and their changes during storage.

    Science.gov (United States)

    Hu, Yue; Huang, Zhiyong; Li, Jian; Yang, Hong

    2012-12-15

    The concentrations of seven biogenic amines (BA) were simultaneously determined in 74 samples of fish, squid and octopus, by the method of HPLC coupled with pre-column derivatisation. The relationship between the formation of BA in aquatic products and the growth of microbial flora during storage was also investigated. Results showed that putrescine, cadaverine, histamine and tyramine were the dominant BA in the studied samples, but the concentrations of histamine and tyramine were mostly less than 50 and 100 mgkg(-1), respectively. Freezing can effectively prevent the formation of BA, but the levels of putrescine, cadaverine, histamine and tyramine significantly increased (poctopus strongly and positively correlated with the formation of amines (such as putrescine, cadaverine, histamine and tyramine) during storage, except for histamine in octopus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. A squid-based beam current monitor for FAIR/CRYRING

    International Nuclear Information System (INIS)

    Geithner, Rene; Stöhlker, Thomas; Kurian, Febin; Reeg, Hansjörg; Schwickert, Marcus; Neubert, Ralf; Seidel, Paul

    2015-01-01

    A SQUID-based beam current monitor was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam currents in the nA-range. The cryogenic current comparator (CCC) was optimized for lowest possible noise-limited current resolution together with a high system bandwidth. This CCC is foreseen to be installed in the CRYRING facility (CRYRING@ESR: A study group report www.gsi.de/fileadmin/SPARC/documents/Cryring/ReportCryring-40ESR.PDF), working as a test bench for FAIR. In this contribution we present results of the completed CCC for FAIR/CRYRING and also arrangements that have been done for the installation of the CCC at CRYRING, regarding the cryostat design. (paper)

  5. Visualization of flowing current in braided carbon fiber reinforced plastics using SQUID gradiometer for nondestructive evaluation

    International Nuclear Information System (INIS)

    Hatsukade, Y; Yoshida, K; Kage, T; Tanaka, S; Takai, Y; Aly-Hassan, M S; Hamada, H; Nakai, A

    2013-01-01

    In this paper, visualization of flowing current in various braided carbon fiber reinforced plastics (CFRPs) was demonstrated using high-temperature superconductor (HTS) superconducting quantum interference device (SQUID) gradiometer, in order to study electrical properties and integrity of the braided CFRP samples. Step-by-step tensile loading was also applied to the samples, in order to study their mechanical properties and destructive mechanism. Experimental results indicated that the addition of carbon nano fibers and middle-end carbon fiber bundles attributed to modify not only the mechanical properties, but also the electrical properties of the samples. Combining the results by the both methods, a scenario of the destructive mechanism of one sample was estimated.

  6. First observations of the bigfin squid Magnapinna sp. in the Colombian Southern Caribbean

    Directory of Open Access Journals (Sweden)

    Jurgen Guerrero-Kommritz

    2018-05-01

    Full Text Available Herein, first observations are reported of Magnapinna squids in the Colombian Southern Caribbean. Two specimens were observed by Remote Operated Vehicles (ROV during exploratory drilling surveys for hydrocarbons at 1,883 and 2,294 m depth. These are the first observations of specimens of Magnapinna in the Southern Caribbean. Resumen La primera observación del calamar Magnapinna sp. en el caribe sur colombiano. Dos especímenes de calamares de aleta grande fueron observados con submarino de operación remota (ROV durante un proyecto de perforación exploratoria de hidrocaburos a profundidades de 1,883 y de 2,294 m, respectivamente. Estas son las primeras observaciones de especímenes de Magnapinna en el Caribe Sur.

  7. First observations of the bigfin squid Magnapinna sp. in the Colombian Southern Caribbean.

    Science.gov (United States)

    Guerrero-Kommritz, Jurgen; Cantera, Jaime; Puentes, Vladimir; Leon, Jorge

    2018-01-01

    Herein, first observations are reported of Magnapinna squids in the Colombian Southern Caribbean. Two specimens were observed by Remote Operated Vehicles (ROV) during exploratory drilling surveys for hydrocarbons at 1,883 and 2,294 m depth. These are the first observations of specimens of Magnapinna in the Southern Caribbean. Resumen La primera observación del calamar Magnapinna sp. en el caribe sur colombiano. Dos especímenes de calamares de aleta grande fueron observados con submarino de operación remota (ROV) durante un proyecto de perforación exploratoria de hidrocaburos a profundidades de 1,883 y de 2,294 m, respectivamente. Estas son las primeras observaciones de especímenes de Magnapinna en el Caribe Sur.

  8. DC current distribution mapping system of the solar panels using a HTS-SQUID gradiometer

    International Nuclear Information System (INIS)

    Miyazaki, Shingo; Kasuya, Syohei; Saari, Mohd Mawardi; Sakai, Kenji; Kiwa, Toshihiko; Tsukada, Keiji; Tsukamoto, Akira; Adachi, Seiji; Tanabe, Keiichi

    2014-01-01

    Solar panels are expected to play a major role as a source of sustainable energy. In order to evaluate solar panels, non-destructive tests, such as defect inspections and response property evaluations, are necessary. We developed a DC current distribution mapping system of the solar panels using a High Critical Temperature Superconductor Superconducting Quantum Interference Device (HTS-SQUID) gradiometer with ramp edge type Josephson junctions. Two independent components of the magnetic fields perpendicular to the panel surface (∂Bz/∂x, ∂Bz/∂y) were detected. The direct current of the solar panel is visualized by calculating the composition of the two signal components, the phase angle, and mapping the DC current vector. The developed system can evaluate the uniformity of DC current distributions precisely and may be applicable for defect detection of solar panels.

  9. Evidence that glutamate mediates axon-to-Schwann cell signaling in the squid.

    Science.gov (United States)

    Lieberman, E M; Abbott, N J; Hassan, S

    1989-01-01

    High-frequency stimulation (100 Hz) of isolated giant axons of the small squid Alloteuthis subulata and the large squid Loligo forbesi caused the periaxonal Schwann cell resting potential (Em = -40 mV) to hyperpolarize up to 11 mV in direct proportion to train duration and action potential amplitude. In both species, the Schwann cell also hyperpolarized up to 17 mV with the application of L-glutamate (10(-9) to 10(-6) M), in a dose-dependent manner. By contrast, in the presence of 10(-8) M d-tubocurarine (d-TC) to block the cholinergic component of the Schwann cell response, Schwann cells depolarized 8-9 mV during electrical stimulation of the axon or application of L-glutamate. In the presence of 10(-5) M 2-amino-4-phosphonobutyrate (2-APB), the hyperpolarization to glutamate and to axon stimulation was blocked, whereas the cholinergic (carbachol-induced) hyperpolarization was unaffected. In experiments with Alloteuthis, L-aspartate (10(-7) M) also caused a Schwann cell hyperpolarization, but this was not blocked by 2-APB. In tests with glutamate receptor agonists and antagonists, quisqualate (10(-5) M) produced a hyperpolarization blocked by 10(-4) M L-glutamic acid diethylester (GDEE), which also blocked the response to axonal stimulation. Kainic acid (10(-4) M) also caused a hyperpolarization, but n-methyl-D-aspartate (NMDA; 10(-4) M), ibotenate (10(-5) M), alpha-amino-3-hydroxy-5-methyl-isoxazole proprionate (AMPA; (10(-4) M), and isethionate (10(-5) M) had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Sub-millimeter scale magnetostratigraphy and environmental magnetism of ferromanganese crusts using a scanning SQUID microscope

    Science.gov (United States)

    Oda, H.; Noguchi, A.; Yamamoto, Y.; Usui, A.; Ito, T.; Kawai, J.; Takahashi, H.

    2017-12-01

    Ferromanganese crusts are chemical sedimentary rock composed mainly of iron-manganese oxide. Because the ferromanganese crusts grow very slowly on the sea floor at rates of 3-10 mm/Ma, long-term deep-sea environmental changes can be reconstructed from the ferromanganese crusts. Thus, it is important to provide reliable age model for the crusts. For the past decades 10Be/9Be dating method has been used extensively to give age models for crusts younger than 15 Ma. Alternatively, sub-millimeter scale magnetostratigraphic study on a ferromanganese crust sample using a scanning SQUID (superconducting quantum interference device) microscope (Kawai et al., 2016; Oda et al., 2016) has been applied successfully (e.g. Oda et al., 2011; Noguchi et al. 2017). Also, environmental magnetic mapping was successful for the ferromanganese crust from the Takuyo Daigo Seamount (Noguchi et al., 2017). The ferromanganese crust used in this study was sampled from the Hanzawa Seamount, Ryukyu trench and the Shotoku Seamount. The vertical component of the magnetic field above thin section samples of the ferromanganese crust was measured using the scanning SQUID microscope on 100 μm grids. Magnetic mapping of the Hanzawa Seamount shows sub-millimeter scale magnetic stripes parallel to lamina. By correlating the boundaries of magnetic stripes with known geomagnetic reversals, we estimated that average growth rate of the Hanzawa Seamount is 2.67 +/- 0.04 mm/Ma , which is consistent with that deduced from the 10Be/9Be dating method (2.56 +/- 0.04 mm/Ma). The crust sample from the Shotoku Seamount used by Oda et al. (2011) shows prominent periodical lamination. Further details are going to be discussed together with the environmental magnetic mapping.

  11. Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours.

    Science.gov (United States)

    Iwata, Yoko; Shaw, Paul; Fujiwara, Eiji; Shiba, Kogiku; Kakiuchi, Yasutaka; Hirohashi, Noritaka

    2011-08-10

    Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

  12. Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours

    Directory of Open Access Journals (Sweden)

    Shiba Kogiku

    2011-08-01

    Full Text Available Abstract Background Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm. Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Results Large consort males transfer smaller (average total length = 73 μm sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Conclusions Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external, whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

  13. Phospholipid synthesis in the squid giant axon: incorporation of lipid precursors

    Energy Technology Data Exchange (ETDEWEB)

    Gould, R.M.; Pant, H.; Gainer, H.; Tytell, M.

    1983-05-01

    The squid giant axon and extruded axoplasm from the giant axon were used to study the capacity of axoplasm for phospholipid synthesis. Extruded axoplasm, suspended in chemically defined media, catalyzed the synthesis of phospholipids from all of the precursors tested. /sup 32/P-Labeled inorganic phosphate and gamma-labeled ATP were actively incorporated into phosphatidylinositol phosphate, while (2-/sup 3/H)myo-inositol and L-(/sup 3/H(G))serine were actively incorporated into phosphatidylinositol and phosphatidylserine, respectively. Though less well utilized. (2-/sup 3/H)glycerol was incorporated into phosphatidic acid, phosphatidylinositol, and triglyceride, and methyl-3H)choline and (1-/sup 3/H)ethanolamine were incorporated into phosphatidylcholine and phosphatidylethanolamine, respectively. Isolated squid giant axons were incubated in artificial seawater containing the above precursors. The axoplasm was extruded following the incubations. Although most of the product lipids were recovered in the sheath (composed of cortical axoplasm, axolemma, and surrounding satellite cells), significant amounts (4-20%) were present in the extruded axoplasm. With tritiated choline and myo-inositol, the major labeled phospholipids found in both the extruded axoplasm and the sheath were phosphatidylcholine and phosphatidylinositol, respectively. With both glycerol and phosphate, phosphatidylethanolamine was a major labeled lipid in both axoplasm and sheath. These findings demonstrate that all classes of phospholipids are formed by endogenous synthetic enzymes in axoplasm. In addition, we feel that the different patterns of incorporation by intact axons and extruded axoplasm indicate that surrounding sheath cells contribute lipids to axoplasm. A comprehensive picture of axonal lipid metabolism should include axoplasmic synthesis and glial-axon transfer as pathways complementing the axonal transport of perikaryally formed lipids.

  14. 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.

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

    Science.gov (United States)

    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.

  16. Multiple Mating, Paternity and Complex Fertilisation Patterns in the Chokka Squid Loligo reynaudii.

    Directory of Open Access Journals (Sweden)

    Marie-Jose Naud

    Full Text Available Polyandry is widespread and influences patterns of sexual selection, with implications for sexual conflict over mating. Assessing sperm precedence patterns is a first step towards understanding sperm competition within a female and elucidating the roles of male- and female-controlled factors. In this study behavioural field data and genetic data were combined to investigate polyandry in the chokka squid Loligo reynaudii. Microsatellite DNA-based paternity analysis revealed multiple paternity to be the norm, with 79% of broods sired by at least two males. Genetic data also determined that the male who was guarding the female at the moment of sampling was a sire in 81% of the families tested, highlighting mate guarding as a successful male tactic with postcopulatory benefits linked to sperm deposition site giving privileged access to extruded egg strings. As females lay multiple eggs in capsules (egg strings wherein their position is not altered during maturation it is possible to describe the spatial / temporal sequence of fertilisation / sperm precedence There were four different patterns of fertilisation found among the tested egg strings: 1 unique sire; 2 dominant sire, with one or more rare sires; 3 randomly mixed paternity (two or more sires; and 4 a distinct switch in paternity occurring along the egg string. The latter pattern cannot be explained by a random use of stored sperm, and suggests postcopulatory female sperm choice. Collectively the data indicate multiple levels of male- and female-controlled influences on sperm precedence, and highlights squid as interesting models to study the interplay between sexual and natural selection.

  17. Understanding the Role of Host Hemocytes in a Squid/Vibrio Symbiosis Using Transcriptomics and Proteomics

    Directory of Open Access Journals (Sweden)

    Andrew J. Collins

    2012-05-01

    Full Text Available The symbiosis between the squid, Euprymna scolopes, and the bacterium, Vibrio fischeri, serves as a model for understanding interactions between beneficial bacteria and animal hosts. The establishment and maintenance of the association is highly specific and depends on the selection of V. fischeri and exclusion of non-symbiotic bacteria from the environment. Current evidence suggests that the host’s cellular innate immune system, in the form of macrophage-like hemocytes, helps to mediate host tolerance of V. fischeri. To begin to understand the role of hemocytes in this association, we analyzed these cells by high-throughput 454 transcriptomic and liquid chromatography/ tandem mass spectrometry (LC-MS/MS proteomic analyses. 454 high-throughput sequencing produced 650,686 reads totaling 279.9 Mb while LC-MS/MS analyses of circulating hemocytes putatively identified 702 unique proteins. Several receptors involved with the recognition of microbial associated molecular patterns (MAMPs were identified. Among these was a complete open reading frame (ORF to a putative peptidoglycan recognition protein (EsPGRP5 that has conserved residues for amidase activity. Assembly of the hemocyte transcriptome showed EsPGRP5 had high coverage, suggesting it is among the 5% most abundant transcripts in circulating hemocytes. Other transcripts and proteins identified included members of the conserved NFκB signaling pathway, putative members of the complement pathway, the carbohydrate binding protein galectin, and cephalotoxin. Quantitative PCR of complement-related genes, cephalotoxin, EsPGRP5, and a nitric oxide synthase showed differential expression in circulating hemocytes isolated from adult squid with colonized light organs compared to those for which the symbionts were removed. These data suggest that the presence of the symbiont influences gene expression of the cellular innate immune system of the host.

  18. Does predation risk affect mating behavior? An experimental test in dumpling squid (Euprymna tasmanica.

    Directory of Open Access Journals (Sweden)

    Amanda M Franklin

    Full Text Available One of the most important trade-offs for many animals is that between survival and reproduction. This is particularly apparent when mating increases the risk of predation, either by increasing conspicuousness, reducing mobility or inhibiting an individual's ability to detect predators. Individuals may mitigate the risk of predation by altering their reproductive behavior (e.g. increasing anti-predator responses to reduce conspicuousness. The degree to which individuals modulate their reproductive behavior in relation to predation risk is difficult to predict because both the optimal investment in current and future reproduction (due to life-history strategies and level of predation risk may differ between the sexes and among species. Here, we investigate the effect of increased predation risk on the reproductive behavior of dumpling squid (Euprymna tasmanica.Females, but not males, showed a substantial increase in the number of inks (an anti-predator behavior before mating commenced in the presence of a predator (sand flathead Platycephalus bassensis. However, predation risk did not affect copulation duration, the likelihood of mating, female anti-predator behavior during or after mating or male anti-predator behavior at any time.Inking is a common anti-predator defense in cephalopods, thought to act like a smokescreen, decoy or distraction. Female dumpling squid are probably using this form of defense in response to the increase in predation risk prior to mating. Conversely, males were undeterred by the increase in predation risk. A lack of change in these variables may occur if the benefit of completing mating outweighs the risk of predation. Prioritizing current reproduction, even under predation risk, can occur when the chance of future reproduction is low, there is substantial energetic investment into mating, or the potential fitness payoffs of mating are high.

  19. Determination of the Tc distribution for 1000 Transition Edge Sensors

    International Nuclear Information System (INIS)

    Brink, P.L.; Saab, T.; Miller, A.J.; Cabrera, B.; Castle, J.P.; Chang, C.; Young, B.A.; Akerib, D.S.; Discroll, D.; Kamat, S.; Perera, T.A.; Schnee, R.W.; Wang, G.; Emes, J.H.; Gaitskell, R.J.; Mandic, V.; Meunier, P.; Rau, W.; Sadoulet, B.; Seitz, D.N.

    2002-01-01

    The ZIP detectors deployed in the CDMS II experiment utilize phonon sensors comprising W Transition Edge Sensors (TESs). In order to ensure uniform collection of the athermal phonon signal the TESs are dispersed uniformly on one side of a 1 cm thick, 3 inch diameter, disk. Each quadrant contains 1036 TESs connected in parallel to one series-array SQUID amplifier. The initial superconducting transition temperatures of these TESs tend to be too high for our requirements, and substantial gradients make the operation of the detectors difficult. Hence our implementation of Fe-56 ion implantation, as reported at the previous LTD meeting, to reduce in a controlled manner the transition temperature. However, the successful implementation of this ion-implantation scheme requires accurate knowledge of the initial transition temperature of each TES in a given quadrant. We report on our approaches and techniques employed to address the issue of determining the initial Tc distribution

  20. Sensors, Volume 4, Thermal Sensors

    Science.gov (United States)

    Scholz, Jorg; Ricolfi, Teresio

    1996-12-01

    'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume describes the construction and applicational aspects of thermal sensors while presenting a rigorous treatment of the underlying physical principles. It provides a unique overview of the various categories of sensors as well as of specific groups, e.g. temperature sensors (resistance thermometers, thermocouples, and radiation thermometers), noise and acoustic thermometers, heat-flow and mass-flow sensors. Specific facettes of applications are presented by specialists from different fields including process control, automotive technology and cryogenics. This volume is an indispensable reference work and text book for both specialists and newcomers, researchers and developers.

  1. Environmental pH, O2 and Capsular Effects on the Geochemical Composition of Statoliths of Embryonic Squid Doryteuthis opalescens

    Directory of Open Access Journals (Sweden)

    Michael O. Navarro

    2014-07-01

    Full Text Available Spawning market squid lay embryo capsules on the seafloor of the continental shelf of the California Current System (CCS, where ocean acidification, deoxygenation and intensified upwelling lower the pH and [O2]. Squid statolith geochemistry has been shown to reflect the squid’s environment (e.g., seawater temperature and elemental concentration. We used real-world environmental levels of pH and [O2] observed on squid-embryo beds to test in the laboratory whether or not squid statolith geochemistry reflects environmental pH and [O2]. We asked whether pH and [O2] levels might affect the incorporation of element ratios (B:Ca, Mg:Ca, Sr:Ca, Ba:Ca, Pb:Ca, U:Ca into squid embryonic statoliths as (1 individual elements and/or (2 multivariate elemental signatures, and consider future applications as proxies for pH and [O2] exposure. Embryo exposure to high and low pH and [O2] alone and together during development over four weeks only moderately affected elemental concentrations of the statoliths, and uranium was an important element driving these differences. Uranium:Ca was eight-times higher in statoliths exposed to low pHT (7.57–7.58 and low [O2] (79–82 µmol·kg−1 than those exposed to higher ambient pHT (7.92–7.94 and [O2] (241–243 µmol·kg−1. In a separate experiment, exposure to low pHT (7.55–7.56 or low [O2] (83–86 µmol·kg−1 yielded elevated U:Ca and Sr:Ca in the low [O2] treatment only. We found capsular effects on multiple elements in statoliths of all treatments. The multivariate elemental signatures of embryonic statoliths were distinct among capsules, but did not reflect environmental factors (pH and/or [O2]. We show that statoliths of squid embryos developing inside capsules have the potential to reflect environmental pH and [O2], but that these “signals” are generated in concert with the physiological effects of the capsules and embryos themselves.

  2. Imaging, manipulation and flux noise of single Abrikosov vortices in YBa2Cu3O7-δ dc SQUIDs

    International Nuclear Information System (INIS)

    Bailer, Matthias

    2013-01-01

    The thesis deals with the imaging and investigation of single Abrikosov vortices in grain boundary dc SQUIDs1 from the high-temperature superconductor YBa 2 Cu 3 O 7-δ . The low temperature scanning electron microscopy (LTSEM) was used for the measurements, which makes a local, spatially resolved investigation of the electrical properties of materials at low temperatures possible. The advantage over other flux quantum imaging methods is the facility to determine the low-frequency flux noise in the SQUID in the process. Special SQUID designs were created, which allow a reproducible cooling of single flux quanta. Electrical transport and noise measurements were carried out to precharacterise the SQUIDs. Within the scope of the thesis it was the first time that antivortices were imaged with the LTSEM. The possibilities of a manipulation of flux quanta (with the electron beam) were investigated and illustrated. By the averaged measurement of the waveform of a single vortex, linescans with unprecedented resolution could be obtained. This allowed the outstanding comparison of the measured, virtual vortex displacement with various theoretically determined waveforms. The experiments to flux noise provided new insights into the noise behaviour of single flux quanta, which exhibit the typical single fluctuators random telegraph signal, and enabled the analysis of the associated hopping processes. Thus concrete values of the spectral noise power density S r ∼ 196 nm 2 /root(Hz) - 0,28 μm 2 /root(Hz) radially to the SQUID hole could be determined by different, pinned vortices. An influence of the hopping behaviour and therefore of the flux noise succeeded by varying an applied magnetic field. Through tilting the potential course of a vortex, the course of the pinning potential by different hopping processes could be reconstructed using stochastic analysis of the time trace data. With the thesis could be shown convincingly that the vortex imaging method of the LTSEM in

  3. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  4. Gas Sensor

    KAUST Repository

    Luebke, Ryan; Eddaoudi, Mohamed; Omran, Hesham; Belmabkhout, Youssef; Shekhah, Osama; Salama, Khaled N.

    2015-01-01

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  5. Sensor web

    Science.gov (United States)

    Delin, Kevin A. (Inventor); Jackson, Shannon P. (Inventor)

    2011-01-01

    A Sensor Web formed of a number of different sensor pods. Each of the sensor pods include a clock which is synchronized with a master clock so that all of the sensor pods in the Web have a synchronized clock. The synchronization is carried out by first using a coarse synchronization which takes less power, and subsequently carrying out a fine synchronization to make a fine sync of all the pods on the Web. After the synchronization, the pods ping their neighbors to determine which pods are listening and responded, and then only listen during time slots corresponding to those pods which respond.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Reconstructing 3D profiles of flux distribution in array of unshunted Josephson junctions from 2D scanning SQUID microscope images

    International Nuclear Information System (INIS)

    Nascimento, F.M.; Sergeenkov, S.; Araujo-Moreira, F.M.

    2012-01-01

    By using a specially designed algorithm (based on utilizing the so-called Hierarchical Data Format), we report on successful reconstruction of 3D profiles of local flux distribution within artificially prepared arrays of unshunted Nb-AlO x -Nb Josephson junctions from 2D surface images obtained via the scanning SQUID microscope. The analysis of the obtained results suggest that for large sweep areas, the local flux distribution significantly deviates from the conventional picture and exhibits a more complicated avalanche-type behavior with a prominent dendritic structure. -- Highlights: ► The penetration of external magnetic field into an array of Nb-AlO x -Nb Josephson junctions is studied. ► Using Scanning SQUID Microscope, 2D images of local flux distribution within array are obtained. ► Using specially designed pattern recognition algorithm, 3D flux profiles are reconstructed from 2D images.

  9. Thermodynamic analysis of the squid mantle muscles and giant axon during slow swimming and jet escape propulsion

    International Nuclear Information System (INIS)

    Yalçınkaya, Bahar Hazal; Erikli, Şükrü; Özilgen, Burak Arda; Olcay, Ali Bahadır; Sorgüven, Esra; Özilgen, Mustafa

    2016-01-01

    Squids have two substantially different types of muscle fibers: superficial mitochondria rich fibers, which perform aerobic respiration during slow swimming, and central mitochondria poor fibers, which perform anaerobic respiration during jet escape. A detailed thermodynamic analysis shows that during slow swimming, 3.82 J/(kg s) of chemical exergy is consumed, and a total muscle work of 0.28 J/(kg s) is produced. 0.27 J/(kg s) of this is produced by the fin to generate lift, and the rest by the mantle volume contraction. During the jet escape at a speed of 3 mantle length/s, squid consumes an exergy of 9.97 J/(kg s) and produces a muscle work of 0.16 J/(kg s). Exergy destruction rates during slow swimming and jet escape modes are 3.54 and 9.81 J/(kg s), respectively. Exergy destroyed because of the action potential propagation in the squid giant axon is calculated as 0.03 and 0.10 J/(kg s) for the slow and fast swimming modes, respectively. - Highlights: • Slow and fast swimming modes of a squid is thermodynamically analyzed. • As swimming speed increases, respiration mode switches from aerobic to anaerobic, and respiration efficiency decreases. • During fast swimming ca. 2.6 times more chemical exergy is consumed. • Both muscles and giant axon destroy nearly 3 times more exergy during jet escape. • Contraction efficiency decreases from 36.8% to 4.7% as the volume of the passive tissue increases from 5% to 95%.

  10. Population Structure of Vibrio fischeri within the Light Organs of Euprymna scolopes Squid from Two Oahu (Hawaii) Populations▿ †

    OpenAIRE

    Wollenberg, M. S.; Ruby, E. G.

    2008-01-01

    We resolved the intraspecific diversity of Vibrio fischeri, the bioluminescent symbiont of the Hawaiian sepiolid squid Euprymna scolopes, at two previously unexplored morphological and geographical scales. These scales ranged from submillimeter regions within the host light organ to the several kilometers encompassing two host populations around Oahu. To facilitate this effort, we employed both novel and standard genetic and phenotypic assays of light-organ symbiont populations. A V. fischeri...

  11. Enlightenment of old ideas from new investigations: more questions regarding the evolution of bacteriogenic light organs in squids

    OpenAIRE

    Nishiguchi, M. K.; Lopez, J. E.; Boletzky, S. v.

    2004-01-01

    Bioluminescence is widespread among many different types of marine organisms. Metazoans contain two types of luminescence production, bacteriogenic (symbiotic with bacteria) or autogenic, via the production of a luminous secretion or the intrinsic properties of luminous cells. Several species in two families of squids, the Loliginidae and the Sepiolidae (Mollusca: Cephalopoda) harbor bacteriogenic light organs that are found central in the mantle cavity. These light organs are exceptional in ...

  12. Chemical sensors

    International Nuclear Information System (INIS)

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section

  13. Body Size Regression Formulae, Proximate Composition and Energy Density of Eastern Bering Sea Mesopelagic Fish and Squid.

    Science.gov (United States)

    Sinclair, Elizabeth H; Walker, William A; Thomason, James R

    2015-01-01

    The ecological significance of fish and squid of the mesopelagic zone (200 m-1000 m) is evident by their pervasiveness in the diets of a broad spectrum of upper pelagic predators including other fishes and squids, seabirds and marine mammals. As diel vertical migrators, mesopelagic micronekton are recognized as an important trophic link between the deep scattering layer and upper surface waters, yet fundamental aspects of the life history and energetic contribution to the food web for most are undescribed. Here, we present newly derived regression equations for 32 species of mesopelagic fish and squid based on the relationship between body size and the size of hard parts typically used to identify prey species in predator diet studies. We describe the proximate composition and energy density of 31 species collected in the eastern Bering Sea during May 1999 and 2000. Energy values are categorized by body size as a proxy for relative age and can be cross-referenced with the derived regression equations. Data are tabularized to facilitate direct application to predator diet studies and food web models.

  14. Transcriptome analysis of the white body of the squid Euprymna tasmanica with emphasis on immune and hematopoietic gene discovery.

    Directory of Open Access Journals (Sweden)

    Karla A Salazar

    Full Text Available In the mutualistic relationship between the squid Euprymna tasmanica and the bioluminescent bacterium Vibrio fischeri, several host factors, including immune-related proteins, are known to interact and respond specifically and exclusively to the presence of the symbiont. In squid and octopus, the white body is considered to be an immune organ mainly due to the fact that blood cells, or hemocytes, are known to be present in high numbers and in different developmental stages. Hence, the white body has been described as the site of hematopoiesis in cephalopods. However, to our knowledge, there are no studies showing any molecular evidence of such functions. In this study, we performed a transcriptomic analysis of white body tissue of the Southern dumpling squid, E. tasmanica. Our primary goal was to gain insights into the functions of this tissue and to test for the presence of gene transcripts associated with hematopoietic and immune processes. Several hematopoiesis genes including CPSF1, GATA 2, TFIID, and FGFR2 were found to be expressed in the white body. In addition, transcripts associated with immune-related signal transduction pathways, such as the toll-like receptor/NF-κβ, and MAPK pathways were also found, as well as other immune genes previously identified in E. tasmanica's sister species, E. scolopes. This study is the first to analyze an immune organ within cephalopods, and to provide gene expression data supporting the white body as a hematopoietic tissue.

  15. Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Tyler R Schleicher

    Full Text Available The beneficial symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium, Vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. Colonization of the squid light organ by V. fischeri begins a lifelong association with a regulated daily rhythm. Each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial cells. We analyzed the host and symbiont proteomes of adult squid exudate and surrounding light organ epithelial tissue using 1D- and 2D-polyacrylamide gel electrophoresis and multidimensional protein identification technology (MudPIT in an effort to understand the contribution of both partners to the maintenance of this association. These proteomic analyses putatively identified 1581 unique proteins, 870 proteins originating from the symbiont and 711 from the host. Identified host proteins indicate a role of the innate immune system and reactive oxygen species (ROS in regulating the symbiosis. Symbiont proteins detected enhance our understanding of the role of quorum sensing, two-component signaling, motility, and detoxification of ROS and reactive nitrogen species (RNS inside the light organ. This study offers the first proteomic analysis of the symbiotic microenvironment of the adult light organ and provides the identification of proteins important to the regulation of this beneficial association.

  16. Stable isotopes document the trophic structure of a deep-sea cephalopod assemblage including giant octopod and giant squid.

    Science.gov (United States)

    Cherel, Y; Ridoux, V; Spitz, J; Richard, P

    2009-06-23

    Although deep-sea cephalopods are key marine organims, their feeding ecology remains essentially unknown. Here, we report for the first time the trophic structure of an assemblage of these animals (19 species) by measuring the isotopic signature of wings of their lower beaks, which accumulated in stomachs of stranded sperm whales. Overall, the species encompassed a narrow range in delta(13)C values (1.7 per thousand), indicating that they lived in closely related and overlapping habitats. delta(13)C values can be interpreted in terms of distribution with the more (13)C-depleted species (e.g. Stigmatoteuthis arcturi, Vampyroteuthis infernalis) having a more pelagic habitat than the more (13)C-enriched, bathyal species (e.g. Todarodes sagittatus and the giant squid Architeuthis dux). The cephalopods sampled had delta(15)N values ranging 4.6 per thousand, which is consistent with the species spanning approximately 1.5 trophic levels. Neither the giant octopod (Haliphron atlanticus) nor the giant squid reached the highest trophic position. Species delta(15)N was independent of body size, with large squids having both the highest (Taningia danae) and lowest (Lepidoteuthis grimaldii) delta(15)N values. Their trophic position indicates that some species share the top of the food web, together with other megacarnivores such as the sperm whale.

  17. Symmetry-Breaking as a Paradigm to Design Highly-Sensitive Sensor Systems

    Directory of Open Access Journals (Sweden)

    Antonio Palacios

    2015-06-01

    Full Text Available A large class of dynamic sensors have nonlinear input-output characteristics, often corresponding to a bistable potential energy function that controls the evolution of the sensor dynamics. These sensors include magnetic field sensors, e.g., the simple fluxgate magnetometer and the superconducting quantum interference device (SQUID, ferroelectric sensors and mechanical sensors, e.g., acoustic transducers, made with piezoelectric materials. Recently, the possibilities offered by new technologies and materials in realizing miniaturized devices with improved performance have led to renewed interest in a new generation of inexpensive, compact and low-power fluxgate magnetometers and electric-field sensors. In this article, we review the analysis of an alternative approach: a symmetry-based design for highly-sensitive sensor systems. The design incorporates a network architecture that produces collective oscillations induced by the coupling topology, i.e., which sensors are coupled to each other. Under certain symmetry groups, the oscillations in the network emerge via an infinite-period bifurcation, so that at birth, they exhibit a very large period of oscillation. This characteristic renders the oscillatory wave highly sensitive to symmetry-breaking effects, thus leading to a new detection mechanism. Model equations and bifurcation analysis are discussed in great detail. Results from experimental works on networks of fluxgate magnetometers are also included.

  18. Wearable Sensors for Remote Health Monitoring.

    Science.gov (United States)

    Majumder, Sumit; Mondal, Tapas; Deen, M Jamal

    2017-01-12

    Life expectancy in most countries has been increasing continually over the several few decades thanks to significant improvements in medicine, public health, as well as personal and environmental hygiene. However, increased life expectancy combined with falling birth rates are expected to engender a large aging demographic in the near future that would impose significant  burdens on the socio-economic structure of these countries. Therefore, it is essential to develop cost-effective, easy-to-use systems for the sake of elderly healthcare and well-being. Remote health monitoring, based on non-invasive and wearable sensors, actuators and modern communication and information technologies offers an efficient and cost-effective solution that allows the elderly to continue to live in their comfortable home environment instead of expensive healthcare facilities. These systems will also allow healthcare personnel to monitor important physiological signs of their patients in real time, assess health conditions and provide feedback from distant facilities. In this paper, we have presented and compared several low-cost and non-invasive health and activity monitoring systems that were reported in recent years. A survey on textile-based sensors that can potentially be used in wearable systems is also presented. Finally, compatibility of several communication technologies as well as future perspectives and research challenges in remote monitoring systems will be discussed.

  19. Wearable Sensors for Remote Health Monitoring

    Directory of Open Access Journals (Sweden)

    Sumit Majumder

    2017-01-01

    Full Text Available Life expectancy in most countries has been increasing continually over the several few decades thanks to significant improvements in medicine, public health, as well as personal and environmental hygiene. However, increased life expectancy combined with falling birth rates are expected to engender a large aging demographic in the near future that would impose significant  burdens on the socio-economic structure of these countries. Therefore, it is essential to develop cost-effective, easy-to-use systems for the sake of elderly healthcare and well-being. Remote health monitoring, based on non-invasive and wearable sensors, actuators and modern communication and information technologies offers an efficient and cost-effective solution that allows the elderly to continue to live in their comfortable home environment instead of expensive healthcare facilities. These systems will also allow healthcare personnel to monitor important physiological signs of their patients in real time, assess health conditions and provide feedback from distant facilities. In this paper, we have presented and compared several low-cost and non-invasive health and activity monitoring systems that were reported in recent years. A survey on textile-based sensors that can potentially be used in wearable systems is also presented. Finally, compatibility of several communication technologies as well as future perspectives and research challenges in remote monitoring systems will be discussed.

  20. Ultrastructure of the optic gland of the squid Sepiotheutis sepioidea (Cephalopoda: Loliginidae

    Directory of Open Access Journals (Sweden)

    Dwight Arrieche

    1999-12-01

    Full Text Available I describe the fine structure of the optic gland (OG in the tropical squid Sepiotheutis sepioidea at different sexual maturity stages. Squids were collected in Mochima National Park, Venezuela (10°; 20' 22 " - 10°; 24' N; 64° 19' - 64 ° 22' W. Morphometric characteristics and the development of reproductive organs at different sexual maturity stages (female n = 101; male n = 105, were significantly different (ANOVA, p Se examinó la ultraestructura fina de la glándula óptica (GO en varios estadios de desarrollo sexual del calamar tropical Sepiotheutis sepioidea, proveniente de las costas de la Bahía de Mochima, Venezuela (10° 20' 22 " - 10° 24' N; 64° 19' - 64° 22' W. Los parámetros morfométricos y de los órganos reproductivos (hembras n = 101; machos n = 105, presentaron diferencias significativas entre los estados de maduración sexual (ANOVA, p < 0.001, el índice gonadal promedio en las hembras osciló entre 0.1 - 2.95 %, y en los machos entre 0.22 - 1.38 %. La GO son un par de órganos ovales ubicados en el borde posterior del tracto óptico en el cerebro de los cefalópodos, ésta posee los mismos tipos de células descritos en otros cefalópodos con algunas leves diferencias. La célula principal en el estadio de maduración juvenil posee un perfil dendrítico con delgados procesos del citoplasma, abundantes ribosomas, mitocondrias circulares con crestas tubulares, y un núcleo prominente eucromatínico; en el estadio de adulto las células principales presentan las cisternas del retículo endoplasmático rugoso dilatadas concéntricamente en la célula, el aparato de Golgi es activo con abundantes gránulos electron densos de secreción, las mitocondrias son escasas, y el gránulo de lipofucsina es de mayor tamaño. La dimensión del núcleo de la célula principal y la abundancia de organelos, presentaron oscilaciones en las etapas del ciclo de vida.

  1. Effect of single- and two-cycle high hydrostatic pressure treatments on water properties, physicochemical and microbial qualities of minimally processed squids (todarodes pacificus).

    Science.gov (United States)

    Zhang, Yifeng; Jiao, Shunshan; Lian, Zixuan; Deng, Yun; Zhao, Yanyun

    2015-05-01

    This study investigated the effect of single- and two-cycle high hydrostatic pressure (HHP) treatments on water properties, physicochemical, and microbial qualities of squids (Todarodes pacificus) during 4 °C storage for up to 10 d. Single-cycle treatments were applied at 200, 400, or 600 MPa for 20 min (S-200, S-400, and S-600), and two-cycle treatments consisted of two 10 min cycles at 200, 400, or 600 MPa, respectively (T-200, T-400, and T-600). HHP-treated samples had higher (P pressure level caused no significant difference in water state of squids. The two-cycle HHP treatment was more effective in controlling total volatile basic nitrogen, pH, and total plate counts (TPC) of squids during storage, in which TPC of S-600 and T-600 was 2.9 and 1.8 log CFU/g at 10 d, respectively, compared with 7.5 log CFU/g in control. HHP treatments delayed browning discoloration of the squids during storage, and the higher pressure level and two-cycle HHP were more effective. Water properties highly corresponded with color and texture indices of squids. This study demonstrated that the two-cycle HHP treatment was more effective in controlling microbial growth and quality deterioration while having similar impact on the physicochemical and water properties of squids in comparison with the single-cycle treatment, thus more desirable for extending shelf-life of fresh squids. © 2015 Institute of Food Technologists®

  2. Electronic Detection of DNA Hybridization by Coupling Organic Field-Effect Transistor-Based Sensors and Hairpin-Shaped Probes

    Directory of Open Access Journals (Sweden)

    Corrado Napoli

    2018-03-01

    Full Text Available In this paper, the electronic transduction of DNA hybridization is presented by coupling organic charge-modulated field-effect transistors (OCMFETs and hairpin-shaped probes. These probes have shown interesting properties in terms of sensitivity and selectivity in other kinds of assays, in the form of molecular beacons (MBs. Their integration with organic-transistor based sensors, never explored before, paves the way to a new class of low-cost, easy-to-use, and portable genetic sensors with enhanced performances. Thanks to the peculiar characteristics of the employed sensor, measurements can be performed at relatively high ionic strengths, thus optimizing the probes’ functionality without affecting the detection ability of the device. A complete electrical characterization of the sensor is reported, including calibration with different target concentrations in the measurement environment and selectivity evaluation. In particular, DNA hybridization detection for target concentration as low as 100 pM is demonstrated.

  3. Automotive sensors

    Science.gov (United States)

    Marek, Jiri; Illing, Matthias

    2003-01-01

    Sensors are an essential component of most electronic systems in the car. They deliver input parameters for comfort features, engine and emission control as well as for the active and passive safety systems. New technologies such as silicon micromachining play an important role for the introduction of these sensors in all vehicle classes. The importance and use of these sensor technologies in today"s automotive applications will be shown in this article. Finally an outlook on important current developments and new functions in the car will be given.

  4. Piezoceramic Sensors

    CERN Document Server

    Sharapov, Valeriy

    2011-01-01

    This book presents the latest and complete information about various types of piezosensors. A sensor is a converter of the measured physical size to an electric signal. Piezoelectric transducers and sensors are based on piezoelectric effects. They have proven to be versatile tools for the measurement of various processes. They are used for quality assurance, process control and for research and development in many different industries. In each area of application specific requirements to the parameters of transducers and sensors are developed. This book presents the fundamentals, technical des

  5. SQUID-Detected MRI in the Limit of Zero Static Field

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, Nathan Dean [Univ. of California, Berkeley, CA (United States)

    2009-12-14

    This thesis describes an implementation of the so-called"zero-field MRI" (ZFMRI) pulse sequence, which allows for imaging in an arbitrarily low B0 field. The ZFMRI sequence created an effective unidirectional gradient field by using a train of pi pulses to average out the concomitant gradient components during encoding. The signals were acquired using a low-transition temperature dc Superconducting QUantum Interference Device (low-Tc dc SQUID) coupled to a first-order axial gradiometer. The experiments were carried out in a liquid helium dewar which was magnetically shielded with a single-layer mu-metal can around the outside and a superconducting Pb can contained within the helium space. We increased the filling factor of the custom-made, double-walled Pyrex insert by placing the liquid alcohol sample, at a temperature of approximately -50 degrees C, at the center of one loop of the superconducting gradiometer, which was immersed in the helium bath.

  6. Effects of channel blocking on information transmission and energy efficiency in squid giant axons.

    Science.gov (United States)

    Liu, Yujiang; Yue, Yuan; Yu, Yuguo; Liu, Liwei; Yu, Lianchun

    2018-04-01

    Action potentials are the information carriers of neural systems. The generation of action potentials involves the cooperative opening and closing of sodium and potassium channels. This process is metabolically expensive because the ions flowing through open channels need to be restored to maintain concentration gradients of these ions. Toxins like tetraethylammonium can block working ion channels, thus affecting the function and energy cost of neurons. In this paper, by computer simulation of the Hodgkin-Huxley neuron model, we studied the effects of channel blocking with toxins on the information transmission and energy efficiency in squid giant axons. We found that gradually blocking sodium channels will sequentially maximize the information transmission and energy efficiency of the axons, whereas moderate blocking of potassium channels will have little impact on the information transmission and will decrease the energy efficiency. Heavy blocking of potassium channels will cause self-sustained oscillation of membrane potentials. Simultaneously blocking sodium and potassium channels with the same ratio increases both information transmission and energy efficiency. Our results are in line with previous studies suggesting that information processing capacity and energy efficiency can be maximized by regulating the number of active ion channels, and this indicates a viable avenue for future experimentation.

  7. Preservation of squid rings by gamma irradiation. Microbiological, sensory and physicochemical aspects

    International Nuclear Information System (INIS)

    Tomac, A.; Yeannes, M.I.; Cova, M.C.; Narvaiz, Patricia

    2011-01-01

    The aim of this work was to analyze the use of gamma irradiation to preserve squid rings during refrigerated storage. Skinned rings of 'Illex argentinus' were packed in polyethylene/polyamide bags and gamma irradiated at 0, 2, 3 and 4 kGy with a cobalt-60 source at a semi-industrial irradiation facility. Samples were kept at 4 ± 1 °C during transportation, irradiation and 21 storage days. Mesophilic and psychrotrophic aerobic bacteria, Staphylococcus aureus, enterobacteriaceae, total coliforms, Escherichia coli, and sulphite-reducing clostridia were analyzed, as well as p H, total volatile basic nitrogen, color, and sensory parameters like aspect, color, odor, taste, texture and overall acceptability. Irradiation initially reduced three and two log cycles, respectively, of mesophilic and psychrotrophic bacterial counts, trend which was maintained during storage. Enterobacteriaceae and coliform growths were also controlled by this treatment. S. aureus, E. coli and sulphite-reducing clostridia were not detected in any sample. p H and TVBN values increased during storage time, being significantly lower in irradiated samples. Irradiation slowed down color changes during storage, measured as a* and b*. Color difference (DE2000) was significantly higher in control samples as compared to irradiated rings since the 6 th day. Sensory acceptability was not affected by gamma irradiation at any of the applied doses, being shelf-life extended at least 14 days in 3 kGy samples. (author) [es

  8. An Unexpected Diversity of Photoreceptor Classes in the Longfin Squid, Doryteuthis pealeii.

    Science.gov (United States)

    Kingston, Alexandra C N; Wardill, Trevor J; Hanlon, Roger T; Cronin, Thomas W

    2015-01-01

    Cephalopods are famous for their ability to change color and pattern rapidly for signaling and camouflage. They have keen eyes and remarkable vision, made possible by photoreceptors in their retinas. External to the eyes, photoreceptors also exist in parolfactory vesicles and some light organs, where they function using a rhodopsin protein that is identical to that expressed in the retina. Furthermore, dermal chromatophore organs contain rhodopsin and other components of phototransduction (including retinochrome, a photoisomerase first found in the retina), suggesting that they are photoreceptive. In this study, we used a modified whole-mount immunohistochemical technique to explore rhodopsin and retinochrome expression in a number of tissues and organs in the longfin squid, Doryteuthis pealeii. We found that fin central muscles, hair cells (epithelial primary sensory neurons), arm axial ganglia, and sucker peduncle nerves all express rhodopsin and retinochrome proteins. Our findings indicate that these animals possess an unexpected diversity of extraocular photoreceptors and suggest that extraocular photoreception using visual opsins and visual phototransduction machinery is far more widespread throughout cephalopod tissues than previously recognized.

  9. An Unexpected Diversity of Photoreceptor Classes in the Longfin Squid, Doryteuthis pealeii.

    Directory of Open Access Journals (Sweden)

    Alexandra C N Kingston

    Full Text Available Cephalopods are famous for their ability to change color and pattern rapidly for signaling and camouflage. They have keen eyes and remarkable vision, made possible by photoreceptors in their retinas. External to the eyes, photoreceptors also exist in parolfactory vesicles and some light organs, where they function using a rhodopsin protein that is identical to that expressed in the retina. Furthermore, dermal chromatophore organs contain rhodopsin and other components of phototransduction (including retinochrome, a photoisomerase first found in the retina, suggesting that they are photoreceptive. In this study, we used a modified whole-mount immunohistochemical technique to explore rhodopsin and retinochrome expression in a number of tissues and organs in the longfin squid, Doryteuthis pealeii. We found that fin central muscles, hair cells (epithelial primary sensory neurons, arm axial ganglia, and sucker peduncle nerves all express rhodopsin and retinochrome proteins. Our findings indicate that these animals possess an unexpected diversity of extraocular photoreceptors and suggest that extraocular photoreception using visual opsins and visual phototransduction machinery is far more widespread throughout cephalopod tissues than previously recognized.

  10. Sneaker Male Squid Produce Long-lived Spermatozoa by Modulating Their Energy Metabolism.

    Science.gov (United States)

    Hirohashi, Noritaka; Tamura-Nakano, Miwa; Nakaya, Fumio; Iida, Tomohiro; Iwata, Yoko

    2016-09-09

    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 spermatozoa inseminated long before egg spawning can be stored in the seminal receptacle. We found that sneaker spermatozoa exhibited greater persistence in fertilization competence and flagellar motility than consort ones because of a larger amount of flagellar glycogen. Sneaker spermatozoa also showed higher capacities in glucose uptake and lactate efflux. Lactic acidosis was considered to stabilize CO2-triggered self-clustering of sneaker spermatozoa, thus establishing hypoxia-induced metabolic changes and sperm survival. These results, together with comparative omics analyses, suggest that postcopulatory reproductive contexts define sperm longevity by modulating the inherent energy levels and metabolic pathways. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Sneaker Male Squid Produce Long-lived Spermatozoa by Modulating Their Energy Metabolism *

    Science.gov (United States)

    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 spermatozoa inseminated long before egg spawning can be stored in the seminal receptacle. We found that sneaker spermatozoa exhibited greater persistence in fertilization competence and flagellar motility than consort ones because of a larger amount of flagellar glycogen. Sneaker spermatozoa also showed higher capacities in glucose uptake and lactate efflux. Lactic acidosis was considered to stabilize CO2-triggered self-clustering of sneaker spermatozoa, thus establishing hypoxia-induced metabolic changes and sperm survival. These results, together with comparative omics analyses, suggest that postcopulatory reproductive contexts define sperm longevity by modulating the inherent energy levels and metabolic pathways. PMID:27385589

  12. The road to magnesium diboride thin films, Josephson junctions and SQUIDs

    International Nuclear Information System (INIS)

    Brinkman, Alexander; Mijatovic, Dragana; Hilgenkamp, Hans; Rijnders, Guus; Oomen, Ingrid; Veldhuis, Dick; Roesthuis, Frank; Rogalla, Horst; Blank, Dave H A

    2003-01-01

    The remarkably high critical temperature at which magnesium diboride (MgB 2 ) undergoes transition to the superconducting state, T c ∼ 40 K, has aroused great interest and has encouraged many groups to explore the properties and application potential of this novel superconductor. For many electronic applications and further basic studies, the availability of superconducting thin films is of great importance. Several groups have succeeded in fabricating superconducting MgB 2 films. An overview of the deposition techniques for MgB 2 thin film growth will be given, with a special focus on the in situ two-step process. Although, meanwhile, many problems to obtain suitable films have been solved, such as oxygen impurities and magnesium volatility, the question of how single-phase epitaxial films can be grown still remains. The possibility of growing single-crystalline epitaxial films will be discussed from the deposition conditions' point of view as well as substrate choice. Necessary conditions are discussed and possible routes are reviewed. The applicability of MgB 2 in superconducting electronic devices depends on the possibility of making well-controlled, i.e., reproducible and stable, Josephson junctions. The first attempts to make MgB 2 -MgO-MgB 2 ramp-type junctions and SQUIDs from MgB 2 nanobridges are discussed

  13. dc SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

    International Nuclear Information System (INIS)

    Seppae, H.

    1992-01-01

    A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5x10 -7 Φ 0 /√Hz at 1 kHz and 2x10 -6 Φ 0 /√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 Φ 0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI 3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz. (orig.)

  14. Squids, supercurrents, and slope anomalies: Nuclear structure from heavy-ion transfer reactions

    International Nuclear Information System (INIS)

    Guidry, M.W.

    1989-01-01

    Within the past five years we have developed experimental techniques to study heavy-ion transfer reactions to high spin states in deformed nuclei. These methods have been turned into a quantitative tool to assess the influence of collective excitation on single-particle and pairing structure. I discuss some of the nuclear structure questions which are being answered in these experiments: How strong is ground state pairing? How does pairing change with angular momentum? Why is two-neutron transfer much stronger than expected at large radial separation? What is the evidence for a nuclear Josephson Effect? What is the evidence for a nuclear Berry phase effect (nuclear SQUID)? Why does one-neutron transfer populate much higher spins than would be naively expected? Conversely, why does two-neutron transfer populate much lower spins than anyone expected? The answer to each of these questions involves the influence of detailed nuclear structure on transfer reactions, and represents quantitative new information about the effect of angular momentum and excitation energy on many-body systems with a finite number of particles. 8 refs., 6 figs

  15. Chitosan nanoparticles from marine squid protect liver cells against N-diethylnitrosoamine-induced hepatocellular carcinoma.

    Science.gov (United States)

    Subhapradha, Namasivayam; Shanmugam, Vairamani; Shanmugam, Annaian

    2017-09-01

    Rationale of this study was framed to investigate the protective effect and anti-cancer property of nanoparticles based on chitosan isolated from squid, Sepioteuthis lessoniana, on hepatic cells in N-Nitrosodiethylamine-induced hepatocellular carcinoma in rats. The results conferred that the chitosan nanoparticle supplementation had a protective effect on liver cells by reducing the levels of marker enzymes and bilirubin and thus increasing the albumin levels. The level of reduced glutathione, ascorbic acid and α-tocopherol significantly increased in both post- and pre-treatment with chitosan nanoparticles. The levels of antioxidant enzymes were enhanced and lipid peroxidation products were diminished while treating nitrosodiethylamine-induced hepatocellular carcinoma with chitosan nanoparticles. Supplementation of chitosan nanoparticles had potent anti-hyperlipidemic property that was evidenced by monitoring the serum lipid levels and its components. Animals pre-treated with chitosan nanoparticles along with nitrosodiethylamine showed a significant reduction in the total cholesterol and triglycerides levels with increase in the levels of phospholipids and free fatty acids. Chitosan nanoparticles treated rats showed significant increment in high-density lipoprotein cholesterol and reduction in low-density lipoprotein and very low-density lipoprotein cholesterol when compared with levels in nitrosodiethylamine-induced hepatocellular carcinoma. Nitrosodiethylamine-induced carcinoma changes on circulation and hepatic antioxidant defense mechanism were regulated by chitosan nanoparticles, concluding that the chitosan nanoparticles have a potent protective effect on liver cells which might be due to its robust antioxidant and anti-lipidemic property. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Open water camouflage via 'leaky' light guides in the midwater squid Galiteuthis.

    Science.gov (United States)

    Holt, Amanda L; Sweeney, Alison M

    2016-06-01

    Galiteuthis, a midwater squid, has photophores on the ventral surfaces of its eyes. These photophores emit bioluminescence to counter-illuminate the shadows cast by the eyes in downwelling sunlight, thereby hiding the eyes from upward-looking predators. The photophores consist of laminated fibre-like cells with semi-coaxial protein-dense layers around axial cytoplasm. These cells have been suggested to function as light guides: bioluminescence is an isotropic process used to hide in an anisotropic light environment, so any emission must be reshaped to be effective. We found a wide variation in cross-sectional geometries of photophore cells; some were more efficient at light guiding than others. We used a set of optical models to place these photophores in the context of the radiance where Galiteuthis lives and discovered a possible adaptive reason for this variation. In Galiteuthis's horizontal and vertical range, ocean radiance is also quite variable. For complete camouflage, photophores must reproduce this variation in radiance using an isotropic source. Our models show that variation in the geometry of the photophore light guides reproduces the predicted variation in ocean radiance experienced by this species. By selectively activating geometrically distinct populations of photophore cells, the animal may reproduce the angular distribution of light at all positions in its habitat. © 2016 The Author(s).

  17. Embryonic Development of the Light Organ of the Sepiolid Squid Euprymna scolopes Berry.

    Science.gov (United States)

    Montgomery, M K; McFall-Ngai, M

    1993-06-01

    The sepiolid squid Euprymna scolopes maintains luminous bacterial symbionts of the species Vibrio fischeri in a bilobed light organ partially embedded in the ventral surface of the ink sac. Anatomical and ultrastructural observations of the light organ during embryogenesis indicate that the organ begins development as a paired proliferation of the mesoderm of the hindgut-ink sac complex. Three-dimensional reconstruction of the incipient light organ of a newly hatched juvenile revealed the presence of three pairs of sacculate crypts, each crypt joined to a pore on the surface of the light organ by a ciliated duct. The crypts, which become populated with bacterial symbionts within hours after the juvenile hatches, appear to result from sequential paired invaginations of the surface epithelium of the hindgut-ink sac complex during embryogenesis. A pair of anterior and a pair of posterior ciliated epithelial appendages, which may facilitate infection of the incipient light organ with symbiotic bacteria, develop by extension and growth of the surface epithelium. The ink sac and reflector develop dorsal to the crypts and together function to direct luminescence ventrally. These two accessory tissues are present at the time of hatching, although changes in their overall structure accompany growth and maturation of the light organ. A third accessory tissue, the muscle-derived lens, appears during post-hatch maturation of the light organ.

  18. K/Na-triggered bioluminescence in the oceanic squid Symplectoteuthis oualaniensis.

    Science.gov (United States)

    Tsuji, F I; Leisman, G B

    1981-11-01

    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 as, in decreasing order of effectiveness, potassium, rubidium, sodium, cesium, ammonium, and lithium. Calcium, magnesium, and strontium ions do not trigger light emission. Analysis of the kinetics of the decay of light intensity suggests that two light-emitting components are involved, one decaying faster than the other. The light-emitting reaction has an absolute requirement for molecular oxygen. The optimum KCl or NaCl concentration is approximately 0.6 M and the optimum pH is approximately 7.8. A free sulfhydryl group is essential for activity.

  19. Differential conductivity mapping of solar panels using a high-TC superconductor SQUID

    International Nuclear Information System (INIS)

    Kiwa, T.; Maeda, S.; Miyake, K.; Kataoka, N.; Tsukamoto, A.; Adachi, S.; Tanabe, K.; Kandori, A.; Tsukada, K.

    2011-01-01

    To visualise the distribution of the electric property of solar cells, we developed a differential conductivity mapping system using high-T C (HTS-) superconductor SQUID with a normal conducting pick-up coil. The bias ac voltage with an offset voltage was applied to a solar panel made from amorphous silicon, and the normal component of the generated magnetic field was lock-in-detected. Thus the measured signal was converted to dB/dV properties, which are inverse-proportional to the differential resistivity, as the function of the offset voltage. By scanning the pick-up coil across the panel surface, we obtained the distribution of dB/dV properties across the solar panel was obtained by scanning the pick-up coil across the panel surface. The distribution of dB/dV on the panel differed between when the light source was on and when it was off. This result suggests that the proposed system is a potential tool for diagnosing the electric properties of solar cells.

  20. Nanocrystalline Pd:NiFe2O4 thin films: A selective ethanol gas sensor

    Science.gov (United States)

    Rao, Pratibha; Godbole, R. V.; Bhagwat, Sunita

    2016-10-01

    In this work, Pd:NiFe2O4 thin films were investigated for the detection of reducing gases. These films were fabricated using spray pyrolysis technique and characterized using X-ray diffraction (XRD) to confirm the crystal structure. The surface morphology was studied using scanning electron microscopy (SEM). Magnetization measurements were carried out using SQUID VSM, which shows ferrimagnetic behavior of the samples. These thin film sensors were tested against methanol, ethanol, hydrogen sulfide and liquid petroleum gas, where they were found to be more selective to ethanol. The fabricated thin film sensors exhibited linear response signal for all the gases with concentrations up to 5 w/o Pd. Reduction in optimum operating temperature and enhancement in response was also observed. Pd:NiFe2O4 thin films exhibited faster response and recovery characteristic. These sensors have potential for industrial applications because of their long-term stability, low power requirement and low production cost.