• Title/Summary/Keyword: Korean squid

Search Result 892, Processing Time 0.021 seconds

Noise Properties of Directly-coupled Single-layer High-Tc 2nd-order SQUID Gradiometer

  • 황윤석;안종록;강찬석;이순걸;김진태
    • Progress in Superconductivity
    • /
    • v.3 no.2
    • /
    • pp.163-167
    • /
    • 2002
  • We have fabricated planar-type single-layer second-order high-Tc SQUID gradiometers. The devices consisted of symmetrically designed three parallel-connected square pickup loops that were directly coupled to the SQUID. $YBa_2$$Cu_3$$O_{7}$ film was deposited on $SrTiO_3$ substrate by a PLD system and patterned into a device by the photolithography with ion milling technique. Junctions of the SQUID were either step-edge or bicrystal type. All the structures were formed on a 10 mm $\times$ 5 mm substrate. Balancing of the gradiometer was achieved by adjusting the width of the central pickup loop. The gradiometer noise was measured both inside and outside a magnetically shielded room. Details of the results will be discussed.

  • PDF

Design and Construction of an HTS DC SQUID Electronic Gradiometer NDE system

  • Kim, J.Y.;Han, S.G.;Kang, J.H.;Lee, E.H.;Song, I.H.
    • Progress in Superconductivity
    • /
    • v.1 no.2
    • /
    • pp.115-119
    • /
    • 2000
  • We designed and constructed a non-destructive evaluation system using an HTS DC SQUID electronic gradiometer. Our DC SQUID electronic gradiometer is composed of two DC SQUID magnetometers. The system included a non-magnetic stainless steel cryostat and a set of coaxial exciting coils, which were used to induce an eddy current in the test piece. We also have calculated the eddy current density produced by an exciting coil in any direction of the testing object. We could compute the eddy current density distribution in 3D. The SQUIDs were computer controlled and the output data from the electronic gradiometer was obtained by using a Labview software.

  • PDF

Low Frequency Noise Properties of YBCO SQUID Gradiometers (YBCO SQUID gradiometers의 저주파 잡음 특성 연구)

  • 황태종;김인선;김동호;박용기
    • Progress in Superconductivity
    • /
    • v.4 no.1
    • /
    • pp.68-73
    • /
    • 2002
  • We have fabricated YBCO SQUID 1st order gradiometers on $30^{\circ}$STO bicrystal substrate. The pickup coil size was 3.8mm$\times$3.8mm and baseline was 5mm. Three types of SQUID gradiometer were designed and tested for unshielded operation; solid pickup coil, pickup coil consisting of 4 parallel $ 50\mu\textrm{m}$-wide loops, and solid pickup coil with flux dam. We have investigated external magnetic field dependence of the SQUID gradiometers on the magnetic field noiseproperties. Significant increase of low frequency noise with the application of static field has been observed in the case of parallel and flux dam type pickup coil above threshold field of $1.3 \mu$T. Magnetic field noise at 1 Hz measured in the magnetically shielding room was 30, 165, 480 fTcm/sup -1/Hz/sup -1/2/ for solid type and slot type and parallel loops type, respectively.

  • PDF

Numerical study of topological SQUIDs

  • Soohong, Choi;Yeongmin, Jang;Sara, Arif;Yong-Joo, Doh
    • Progress in Superconductivity and Cryogenics
    • /
    • v.24 no.4
    • /
    • pp.11-15
    • /
    • 2022
  • We conducted numerical calculations to obtain the critical current as a function of the magnetic flux through the topologically trivial and non-trivial superconducting quantum interference devices (SQUIDs), with varying the capacitive and inductive couplings of Josephson junctions (JJs). Our calculation results indicate that a nontrivial SQUID is almost indistinguishable from trivial SQUID, considering the effective capacitance coupling. When the SQUID contains 2π- and 4π-periodic supercurrents, the periodicity of the current-flux relation can be distinguished from the purely trivial or nontrivial SQUID cases, and its difference is sensitive to the relative ratio between the topologically trivial and nontrivial supercurrents. We believe that our calculation results would provide a practical guide to quantitatively measure the portion of the topologically nontrivial supercurrents in experiments.

Drying Characteristics of Squids According to Far Infrared and Heated Air Drying Conditions (원적외선과 열풍 건조조건에 따른 오징어의 건조특성)

  • Kang, Tae-Hwann;Hong, Hyun-Gi;Jeon, Hong-Young;Han, Chung-Su
    • Journal of Biosystems Engineering
    • /
    • v.36 no.2
    • /
    • pp.109-115
    • /
    • 2011
  • Drying characteristics of squids under two dry conditions were investigated using far infrared and heated air. Dry temperatures of 40, 50 and $60^{\circ}C$ with air speed of 0.6, 0.8 and 1.2 m/s were used for evaluating far infrared squid drying. Heated air squid drying at 40 and $50^{\circ}C$ with air speed of 0.8 m/s was used as a control treatment. The two drying were evaluated in terms of drying rate, color, TBA value, aerobic bacteria, cutting shear, penetration strength, and energy consumption. The drying rate of far infrared drying was relatively faster than that of heated air drying. The drying time of far infrared drying was reduced as the drying temperature increased. The color difference of far infrared dried squids was from 18.81 to 22.85, and heated air dried squid had the color different from 23.94 to 24.09. Far infrared dried squid had relatively smaller TBA values that indicate a level of rancidity. The aerobic bacteria of heated air dried squid increased from $970{\times}10^3$ to $40,000{\times}10^3$ CFU/g before and after drying, respectively. Far infrared dried squid had relatively smaller increase (from $970{\times}10^3$ to $40,000{\times}10^3$ CFU/g). The cutting shear and penetration strength for far infrared dried squids was relatively lower. In addition, far infrared squid drying consumed relatively less energy compared to heated air drying.

Design of a 40 channel SQUID system (40채널 SQUID 시스템의 설계)

  • Lee, Y.H.;Kim, J.M.;Kwon, H.C.;Lim, C.M.;Lee, S.K.;Park, Y.K.;Park, J.C.;Lee, D.H.;Shin, J.K.;Ahn, C.B.;Park, M.S.;Hur, Y.;Hong, J.B.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1998 no.11
    • /
    • pp.191-192
    • /
    • 1998
  • We report on the design of a low-noise 40 channel SQUID system for biomagnetism. We used low-noise SQUID sensor with the pickup coil integrated on the same wafer as the SQUID. The SQUID electronics were simplified by increasing the voltage output of the SQUID. The SQUID insert was designed to have low thermal load, minimizing the liquid helium loss. The digital signal processing provides versatile analysis tools and the software is based on the object-oriented programming. For the effective localization of the source location, solutions of the inverse problems based on the lead-field and the simulated anneal ins were studied.

  • PDF

Sequences and Phylogenic Analysis of Squid New Kinesin Superfamily Proteins (KIFs) (오징어과의 Kinesin Superfamily Proteins (KIFs)의 유전자분석 및 계통분석)

  • Kim, Sang-Jin;Seog, Dae-Hyun
    • Journal of Life Science
    • /
    • v.22 no.3
    • /
    • pp.293-297
    • /
    • 2012
  • The movement of vesicles from the neuronal cell body to specific destinations requires molecular motors. The squid giant axon represents a powerful model for studies of the axonal transport mechanism because the axoplasm can readily be separated from the sheath by simple extrusion. In a previous study, vesicular movements in the axoplasm of the squid giant axon were inhibited by the kinesin antibody. In the present study, we cloned and sequenced the cDNAs for squid brain KIFs. Amplification of the conserved nucleotide sequences of the motor domain by polymerase chain reaction (PCR) using first-strand cDNAs of the squid optic lobe identified six new KIF proteins. Motif analysis of the motor domains revealed that the squid KIFs are homologous to the consensus sequences of the mouse KIFs. The phylogenetic tree generated by using the maximum parsimony (MP) method, the neighbor-joining (NJ) method, the minimum evolution (ME) method, and the maximum likelihood (ML) method showed that squid KIFs are closest to mouse KIFs. These data prove the phylogenetic relationships between squid KIFs and mouse ones.

Cholestrol Content and Formation of Oxidized Cholesterols in Processed Squids

  • Hong, Jeung-Hoon;Ryu, Hong-soo;Kim, Heung-Bae
    • Preventive Nutrition and Food Science
    • /
    • v.1 no.2
    • /
    • pp.196-202
    • /
    • 1996
  • The effect of cooking(boiling, steaming and baking0and drying on the cholesterol content and formation of oxidized cholesterols in quid(Japanese flying squid, Todarodes pacificus) was studied. Cholesterol content of live squid meat varied with the portion sampled, and results from spectrophotometric assay ranged from 263.2mg/1..g(mantle) to 315.8mg/100g(tentacle). The cholesterol levels analyzed by gas chromatography(GC) for squid samples were lower by 7% of total cholesterol for live squid meat and 24% for processed meat than those results by spectrophotometric assay. Cooking resulted in the decrease of the initial total cholesterol content of raw meat from 10%(boiling for 5min.) to 25%(steaming for 5min.) The amounts of cholesterol remaining after baking were 68% for microwave oven samples and 64% for convection oven samples. Drying of raw tissue caused the greater reduction in cholesterol content than cooking but showed no significant difference in samples stored for 6 weeks at 4$^{\circ}C$ and 2$0^{\circ}C$. Raw squid meats contained essentially no oxidized cholesterols, while the 22-hydroxychoesterol was detected in frozen meats. The additional oxidized cholesterols as cholestane-triol was indentified with 22-hydroxycholesterols in cooked samples. Sun dried meat stored at 4一 and 2$0^{\circ}C$ for 6 weeks had the three kinds of oxidized cholesterols such as 22-hydroxycholesterol, cholesta-3,5-dien-7-one and cholestane-triol.

  • PDF

High-$T_c$ SQUID Application for Roll to Roll Metallic Contaminant Detector

  • Tanaka, S.;Kitamura, Y.;Uchida, Y.;Hatsukade, Y.;Ohtani, T.;Suzuki, S.
    • Progress in Superconductivity
    • /
    • v.14 no.2
    • /
    • pp.82-86
    • /
    • 2012
  • 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.

A semispherical SQUID magnetometer system using high sensitivity double relaxation oscillation SQUIDs for magnetoencephalographic measurements

  • Lee, Yong-Ho;Hyukchan Kwon;Kim, Jin-Mok;Kim, Kwoong;Park, Yong-Ki
    • Progress in Superconductivity and Cryogenics
    • /
    • v.5 no.1
    • /
    • pp.21-26
    • /
    • 2003
  • We designed and constructed a multichannel superconducting quantum interference device (SQUID) magnetometer system to measure magnetic fields from the human brain. We used a new type of SQUID, the double relaxation oscillation SQUID (DROS). With high flux-to-voltage transfers of the DROS, about 10 times larger than the dc SQUIDs, simple flux-locked loop circuits could be used for SQUID operation. Also the large modulation voltage of the DROS, typically being 100 $mutextrm{V}$, enabled stable flux-locked loop operation against the thermal offset voltage drift of the preamplifier. The magnetometers were fabricated using the Nb/AlOx/Nb junction technology. The SQUID system consists of 37 signal magnetometers, distributed on a semispherical surface, and 11 reference channels were installed to pickup background noises. External feedback was used to eliminate the magnetic coupling with the adjacent channels. The liquid helium dewar has a capacity of 29 L and boil-off rate of about 4 L/d with the total 48 channel insert. The magnetometer system has an average noise level of 3 fT/√Hz at 100 Hz, inside a shielded loon, and was applied to measure auditory-evoked fields.