... YBCO Coated Conductors with Reduced AC Losses ... YBCO Coated Conductor, AC losses, RABiTS, Superconductor, Maganetic Properties ...
DTIC Science & Technology
... SUPERCONDUCTORS, *ELECTRIC FIELDS, *ALTERNATING CURRENT ... SURFACE PROPERTIES, THINNESS, SCALAR FUNCTIONS, LOSSES ...
... Abstract : This report deals with two properties of high field superconductors; namely, their critical current density and ac losses. ...
... AC Loss Minimisation in High Temperature Superconductors ... Extension to AC Loss Minimisation in High Temperature Superconductors ...
We are experimentally studying basic AC loss properties of IBAD/CVD-YBCO coated conductors with a copper layer for stabilizing, especially the temperature dependence of perpendicular field loss in alternating electromagnetic environments. We prepared two types of short specimens with and without a copper layer and ...
NASA Astrophysics Data System (ADS)
This report discusses the AC losses in the MICE channel magnets during magnet charging and discharging. This report talks about the three types of AC losses in the MICE magnets; the hysteretic AC loss in the superconductor, the coupling AC ...
National Technical Information Service (NTIS)
Superconductors with inhomogeneous or filamentary structures are able to carry current distributed right across their cross sections. Because of flux- trapping properties, the form of current distribution will in general depend on the previous history of the specimen and, if a-c are carried, hysteresis in the current distribution is to be expected. ...
Energy Citations Database
The properties of ac hysteresis loop of a stator tooth in a 5 hp induction motor was measured and analyzed. The load increase on the motor decreased magnetic induction, however increase the minor hysteresis loops in the high induction region. This effect caused increase in the core loss. Depending on condition of the motor, the core ...
We studied magnetic properties of biaxially textured Ni_1-xWx materials with x = 0, 3, 5, 6, and 9 at% W. They are important as substrates for ``RABiTS'' coated conductors containing high temperature superconductors. The quasi-static dc and ac hysteretic loss W was determined to estimate the ferromagnetic (FM) contribution to the ...
This paper presents a new finite-element simulation model for computing the electromagnetic properties and AC losses in systems of YBCO (yttrium barium copper oxide) conductors on roll assisted biaxially textured substrates (RABiTS). In this model, the magnetic field dependent permeability and ferromagnetic loss of ...
The magnetic properties, including ac core loss, dc hysteresis loss, eddy current loss, ac and dc permeability at 10 kG and 15 kG, and magnetic flux density at field strength 2,500 A/m, of 17 heats of fully processed, continuous-annealed low-carbon electrical steels with ...
Energy dissipation, which is also called AC loss, of a composite multifilamentary superconducting wire is one of the most fundamental concerns in building a stable superconducting magnet. Characterization and reduction of AC losses are especially important in designing a superconducting magnet for generating ...
This paper investigates the electromagnetic properties of high-temperature superconductors with a particular focus on the AC loss in coils made from YBCO superconductors. The numerical analysis and finite element modelling of the YBCO superconductors used in Cambridge�s superconducting permanent magnet synchronous motor currently in ...
... Extension to AC Loss Minimisation in High Temperature Superconductors ... The transport AC loss decreases more than 3 times. ...
AFRL-PR-WP-TP-2006-208 AC LOSS REDUCTION OF YBCO ... SUBJECT TERMS AC losses, coated conductors, YBCO, multifilamentary 16. ...
The successful application of superconductivity to motors and other power system components depends on the characterization and subsequent minimization of the ac loss in the superconductor used for fabrication of the component. The superconductive component, excited by an ac power source, may be exposed to large dc magnetic fields ...
We investigate the AC loss of a high-0953-2048/10/8/004/img2 superconducting power-cable conductor with four layers and interlayer insulation. The electric-circuit model is applied for the calculation of the AC loss of the conductor. The result of a calculation for the AC ...
... Abstract : Results are presented on the AC and DC characteristics of Wausau granite which show that excess AC losses at low temperatures are ...
]�[12]. It is difficult to measure ac loss and stability properties at lower temperatures primarily due to the problems are coplanar with the G10 sample holder as well as the supercon- ducting sample. A resistive heater located superconducting tape. The possibility of obtaining uniform temperature over a 15 cm long sample in 35�80 ...
E-print Network
... Accession Number : ADA461815. Title : AC Loss Reduction of YBCO Coated Conductors by Multifilamentary Structure. Descriptive ...
... Title : AC LOSSES OF SUPERCONDUCTING COMPOSITES WITH 8 MU-M NBTI FILAMENTS IN A DC MAGNETIC FIELD WITH A ...
AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss ...
For near-future applications of REBa2Cu3O7 (REBCO) coated conductors to electric power cables, transformers and Superconducting Magnetic Energy Storage (SMES), the long taped wires with high performance in the transport properties have been designed and fabricated. Moreover, in order to drastically reduce AC losses in perpendicular ...
Lead monoxide filled isophthalate resin particulate polymer composites were prepared with different filler concentrations and investigated for physical, thermal, mechanical and gamma radiation shielding characteristics. This paper discusses about the dielectric properties of the composites. The present study showed that the dielectric constant (?'), dielectric ...
The favorable nuclear properties of actinium-225 ((225)Ac) have led to proposal of this isotope for use in radioimmunotherapy. In an effort to reduce the toxicity of free (225)Ac, a series of ligands were evaluated for stability in vivo. Loss of (225)Ac from acyclic chelating agents resulted in ...
PubMed
The report includes brief summaries of theoretical studies of pure and impurity-doped insulators and metals with the object of understanding the sources of energy loss in magnetic materials used in AC instrumentation. Also studied are surface effects on m...
This report describes work concerning the properties of the high- temperature oxide superconductors. This work falls into four general areas: ac losses in the superconducting state, ac losses in the normal state, anisotropy in the superconducting state, and monitoring developments in ...
A simple model gave utilized for calculation of magnetization effects on ac loss and sextupole for Energy Doubler dipole magnets. The calculation in the simple model gave an underestimation of ac loss by about 30%. Results of computation on ac harmonics were also described.
DOE Information Bridge
Magnetism can affect losses in superconducting coils in two ways. First, there is magnetic loss ('core loss'). This can be separately measured as a function of magnetic induction in the material of interest (usually the substrate on which a superconducting film is grown). One can then find the fields in the coil when a current is ...
Ni-W alloys are used as the substrate in the manufacture of HTS tape via the RABiTSTM process. Theoretical work has shown that the ferromagnetism in a substrate can affect the ac losses in the superconductor. This occurs in part because of the increased magnetic permeability, which alters the magnetic induction in the superconductor and thereby the ...
Critical-current density, upper critical field, and hysteresis ac losses have been evaluated for a large (100-m long) sample of in situ formed Cu-Nb/sub 3/Sn composite with superconducting volume fraction lambdaapprox. =0.23. The magnetic field dependence of the critical current, measured in wire and tape samples of different reductions, cannot be ...
Impedance spectroscopy has been used to study the effect of kaolinite grain sizes on the AC electrical properties of kaolinite/polystyrene composites under different temperatures and applied frequencies. Impedance measurements were performed on prepared composites containing 20% kaolinite mineral of grain sizes 63, 106, 212, and 300 ?m in addition to neat ...
Abstracts are given of presentations covering: superconducting device fabrication; applications of rf superconductivity; conductor stability and losses; detectors and signal processing; fusion magnets; A15 and Nb-Ti conductors; stability, losses, and various conductors; SQUID applications; new applications of superconductivity; advanced conductor ...
This report summarizes work on NbTi composite superconductors for the work period of July 1st, 1990 to June 30, 1991. Topic discussed are: properties of the filament, properties of the stabilizer, mechanism of proximity effect coupling, hysteretic AC losses, and published papers. (JL)
This report discusses the AC losses in the MICE channelmagnets during magnet charging and discharging. This report talks aboutthe three types of AC losses in the MICE magnets; the hysteretic AC lossin the superconductor, the coupling AC loss in the ...
... Title : High Frequency Properties of Electron Waveguides, AC- Admittance, Scattering Parameters, Plasma Oscillations. ...
Ac loss measurements have been performed in samples of a prototype conductor being developed for application in the central solenoid of NET. Two types of losses have been measured: hysteresis losses in the strand, and coupling losses in the strand, subcab...
The theory and calculation of a.c. losses in type II superconducting materials and superconducting coils are presented. The calculated losses are compared to loss-measurements in solenoids performed by several laboratories. Methods of loss measurements are described. (author)
Page 1. AFRL-PR-WP-TP-2006-210 LOW AC LOSS STRUCTURES IN ... 2, JUNE 2005 2827 Low AC Loss Structures in YBCO Coated Conductors ...
This paper discusses the physics of ac losses in type-II superconductors and in multifilamentary superconducting-normal composite conductors. As an introduction, the ac eddy-current losses in a homogeneous normal conducting cylindrical specimen subjected ...
This lecture discusses the physics of ac losses in type-II superconductors and in multifilamentary superconducting-normal composite conductors. As an introduction, the ac eddy-current losses in a homogeneous normal conducting cylindrical specimen subjecte...
We fabricated and characterized the Bi2223 tape with Al2O3 as interfilamentary resistive barriers for the filament decoupling and also for the reduction of AC losses under AC external magnetic field. The tapes with thin Al2O3 barrier layers around the Bi2223 filaments were prepared by using a standard powder-in-tube (PIT) method. Al2O3 ...
Future use of coated conductors in electric power applications like transmission cables, transformers or fault current limiters is sensitive to the amount of dissipation in the AC regime. This paper analyses factors controlling AC loss of coated conductors in typical configurations: the self-field case when transport current generates ...
This paper reports on microwave properties of high T{sub c} oxides. The frequency and temperature dependences of the impedance are obtained. Short coherence length leads to large losses. The effects of impurities and multi-gap structures are discussed. The impedance of the proximity system is calculated. The presence of the acoustic plasmon branch leads to ...
... Accession Number : ADA481255. Title : YBCO Coated Conductors with Reduced AC Losses. Descriptive Note : Final technical rept. ...
... Accession Number : ADA346511. Title : Program to Study AC Loss in High-Tc Superconductors. Descriptive Note : Final technical rept. ...
... Accession Number : ADA038393. Title : Measurements of AC Losses in Superconductors below Hc1. Descriptive Note : Final rept. Jan 74-Jun 76,. ...
... Title : Low AC Loss Structures in YBCO Coated Conductors With Filamentary ... Personal Author(s) : Barnes, Paul N. ; Levin, George A. ; Varanasi ...
... Abstract : This report results from a contract tasking University of Cambridge as follows: The contractor will investigate: 1) AC losses of appropriate ...
... report results from a contract tasking University of Cambridge as follows: The contractor will investigate: (a) Measure the AC losses of appropriate ...
... Title : Critical Currents and AC Losses in Model YBCO ... HALL EFFECT, ELECTRIC FIELDS, ALTERNATING CURRENT, OXIDES, COPPER ...
... Using the two-dimensional FEM model for electromagnetic field analysis of coated conductors, the AC losses at various conditions were calculated ...
... Title : AC LOSSES IN A MULTIFILAMENTARY NB3AL/CU COMPOSITE SUPERCONDUCTOR MADE BY A JELLY ROLL PROCESS. ...
Some electrical properties, such as piezoelectricity, ac conductivity, dielectric constant and loss tangent of nine commercial types of dental composite restorative materials, have been investigated before and after laser exposure for 3s to study the effect of a probable laser exposure during some surgeries on the electrical ...
Glass ceramic superconductors were prepared by the melt-quenching method. The frequency and temperature dependence of dielectric constant ( ?'), dielectric loss ( ??) and loss tangent (tan ?) of these superconductors were investigated in the frequency range of 10 kHz-10 MHz and temperature range of 80-300 K using the capacitance-voltage (C-V) and ...
can increase the losses of the capacitor significantly. Fortunately, very lit- tle ac current flowsCapacity Limits and Matching Properties of Lateral Flux Integrated Capacitors Roberto Aparicio-fractal capacitors are calculated. These limits are used to investigate the efficiency of various capacitive struc
One of the major objectives of the Large Coil Task (LCT) is to demonstrate that large-scale magnet systems can be operated stably and safely while subjected to external transient disturbances. This paper reviews the design of the conductor and the coil structure of all six LCT coils with special emphasis on their ac loss properties. ...
... TERMS magnetization losses, superconductor, YBCO coated ... of coated super- conductors in demanding ac ... Theory of Superconductors Tay- lor and ...
... ALTERNATING CURRENT, CRITICAL TEMPERATURE, LOSSES, HYSTERESIS, UNITED KINGDOM, YTTRIUM BARIUM COPPER OXIDES. ...
... The main obstacle to the use of superconductors in electrical machines in ... superconducting cylinder (ie the losses in the superconductor plus the ...
... MATHEMATICAL MODELS, ALTERNATING CURRENT, LOSSES, MAGNETIZATION, COPPER OXIDES, YTTRIUM OXIDES, BARIUM OXIDES ...
The objective of the program was to study the feasibility of Nb3Ge being used as an AC superconducting power transmission cable material. Specifically, the program was to measure AC losses in available samples of Nb3Ge and find under what conditions the l...
The purpose of this study was to evaluate the effect of carcass chilling methods on marination properties, tenderness, sensory attributes, and consumer acceptance of broiler breast fillets. A total of 120 broilers were slaughtered at 6 wk of age. Carcasses were either immersion chilled (in a 2-stage prechill-chill system; IC) or air chilled (AC) and then ...
... are superconducting. The design of such a machine is dominated by the AC losses which occur in the armature. Most superconducting ...
Establishment of processing technology for multifilamentary coated conductors (CCs) is a key issue for superconducting electric power applications from the viewpoint of AC loss reduction. On the other hand, CCs sometimes have local inhomogeneity in the superconducting layers, and that will cause a current blocking in a filament or inhomogeneity of critical ...
Interstrand AC losses and contact resistances of Rutherford cables are easily affected by curing conditions. The authors have measured the interstrand AC losses and contact resistances for three kinds of Rutherford cables, made from strands with a Cu matrix, a CuMn barrier around a filamentary bundle and a CuMn ...
AC losses must be considered in SMES during discharging of the coil. This is especially true for very fast discharges. In particular, the SMES/Engineering Test Model (ETM) should be able to demonstrate the capability to discharge at 400 MW for 100 seconds. It is important to quantify AC losses to ascertain its ...
We have tried to determine the effects of 60Co gamma irradiation on properties of Au/SnO2/n-Si (MOS) structures such as dielectric constant (??), dielectric loss (??), tangent loss (tan ?) and ac conductivity (?ac). Three samples were fabricated with different deposition time. The samples were ...
PbO-Ga2O3-P2O5 glasses containing different concentrations of Cr2O3 ranging from 0 to 1.0 mol % were prepared. The differential thermal analysis and dielectric properties (viz., constant epsilon', loss tan ?, a.c. conductivity ?ac over a wide range of frequency and temperature) have been studied as a function of ...
The feasibility of superconductors for alternating current use depends on successful reduction of losses. Moreover, the demand for large field amplitudes is a stimulation for investigating the nature of a.c. losses (e.g. in the set of poloidal coils in a ...
A series of M-type hexaferrite samples with composition Sr{1-x}La{x}Fe{12}O{19} (x = 0.00, 0.05, 0.15 and 0.25) were prepared by standard ceramic technique. AC electrical conductivity measurements were carried out at different frequencies (20 Hz 1 MHz) and at different temperatures. The dielectric constant and dielectric loss tangent were measured in the ...
The effects of sulfur content and slab reheating temperature on the magnetic properties of four fully processed nonoriented electrical steels have been investigated. Four slabs of nonoriented electrical steels with sulfur content in the range of 0.0006 0.0126 wt% were reheated to 1100, 1200, and 1300 �C, respectively. Then, they were hot rolled and annealed at 700 �C, cold ...
An empirical relation is presented which allows simple computation of volume-averaged winding fields from central fields for coils of small rectangular cross sections. This relation suggests that, in certain applications, ac-loss minimization can be accomplished by use of low winding densities, provided that hysteresis losses are independent of winding ...
Page 1. Electrical and Magnetic Properties of D6ac Steel SK Burke and ME Ibrahim ... Page 3. Electrical and Magnetic Properties of D6ac Steel ...
The variation of the relative permittivity epsilon'sub(r), the loss factor epsilon'' and a.c. conductivity sigma with the frequency of an applied electromagnetic field over the range 0.5 to 50 MHz has been studied in the leaf and stem tissues of three tro...
In this paper we discuss a novel material which has nearly ideal properties at optical frequencies. It combines the low dissipation of a dielectric with the reflectivity of a metal. This material employs a two-dimensional photonic band gap structure to ac...
Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac ...
AC loss is one of the main issues in the design of the CICC used for PF and TF coils of superconducting tokamak. A preliminary calculation of AC loss for the designed HT-7U CICCs used for TF magnets is given in this paper. We only consider the hysteresis and coupling losses related to ...
Magnetization AC losses in striated YBCO conductors in a perpendicular applied AC magnetic field were investigated with special regard to the coupling current AC loss (CCAC). The AC loss of YBCO samples of different length L was measured by using ...
Complex impedance spectroscopic studies were carried out on RbNO3 and RbNO3 Al2O3 dispersed solid electrolyte systems (DSES) in the temperature range of 50 �C to 300 �C and the frequency 50 KHz to 1 MHz. Dielectric constant, loss tangent, and AC conductivity, in these systems are presented. Dielectric constant, loss and ...
Poly(butylenes adipate) ionomers (PBAi) were synthesized using dimethyl 5-sulfoisophthalate sodium salt (DMSI) up to 5 mol% of diacid monomer. We have investigated electrical and dielectric properties of the ionomers to evaluate alternating current (AC) parameters such as impedance, conductance, dielectric constant, admittance, susceptance, dielectric ...
... and References Search GIVE BACK � RELATED LINKS ACS Gift Shop ACS Bookstore MoreBirthdays.com ACSCAN.org Hair Loss ...
MedlinePLUS
... motion compensation will be assumed to avoid any target signal loss incurred in integration. ... the DC part &(v) and the AC spectrum pAc(v) due to ...
Development of the superconducting transformer is arguably the most difficult of the ac power applications of superconductivity - this is because of the need for very low ac losses, adequate fault and surge performance, and the rigors of the application e...
AC losses increased rapidly with frequency and quadratically with AC amplitude. Above about 2 hz, the effective resistance of the control coils exceeds that ...
NASA Website
Glass crystallisation method is used as a relatively new technique for the preparation of nanocrystalline magnetic iron oxide. Properties of glassy flakes, the precursor state, prepared powders as well as a water-based ferrofluid were analysed by XRD, TEM and magnetic methods. Different contributions to specific loss power (SLP) are measured by ...
In this paper we present a finite element model using the commercial COMSOL software package for calculating the ac loss in bifilar stacks of high temperature superconducting tape. In the model, the current-voltage relationship characterizing the superconducting properties is assumed to follow a power law. The calculations were ...
In electrical power devices, ac losses from a superconductor is a primary factor which determines their usefulness as commercial power equipment. For this reason, extensive studies have been carried out on the losses of Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}/Ag, [Bi(2223)/Ag], tapes. These studies were mostly limited to a single ...
Amorphous carbon (a-C) films grow via energetic processes such as pulsed-laser deposition (PLD). The cold-cathode electron emission properties of a-C are promising for flat-panel display and vacuum microelectronics technologies. These ultrahard films consist of a mixture of 3-fold and 4-fold coordinated carbon atoms, resulting in an ...
... Accession Number : ADD134918. Title : Mechanical Properties of D6ac Steel Forging, Billet and Plate,. Descriptive Note : Technical Rept.,. ...
... Accession Number : ADA474883. Title : Electrical and Magnetic Properties of D6ac Steel. Descriptive Note : Technical note. ...
... Abstract : The effect of specimen thickness on the notch properties of D6AC steel heat treated to the 240 to 250 ksi strength level has been studied ...
... Title : Effect of Cooling Rate on the Mechanical Properties of AC4CH Aluminum Alloy Castings. Descriptive Note : Journal article,. ...
... ELEVATED TEMPERATURE FATIGUE PROPERTIES OF D6AC HIGH STRENGTH STEEL ... 1. Photomicrograph of D6AC - Vilella's Reagent, 1000X ...
In this paper an improved measurement system for experimental assessment of magnetic fluid losses is presented. When fluid is exposed to AC magnetic field, three different losses mechanisms are active; relaxation, hysteresis and resonance mechanism. In this paper not individual contributions where studied but combine acting which can ...
Critical currents and AC losses of (Bi, Pb)2Sr2Ca2Cu3Ox superconducting tapes were measured in self-field as a function of temperature. The experimental data of the temperature dependence of critical current were compared with calculated results. An approach to calculating AC losses as a function of temperature was ...
In this paper a description is given of a method to measure calorimetrically ac losses in superconducting samples. The boil-off gas is stored below the liquid helium level in a measuring tube. Losses in the range of 1 mW up to 100 mW can be measured with an accuracy of 3%. Results of measurements of ac ...
Code Section 613A(c) (10) sets forth an exception, for transfers by individuals to their controlled corporations, to the general rule of section 613A(c)(9) denying percentage depletion to transferees of proven oil and gas properties. The proposed regulations attempt to provide guidelines to help taxpayers comply, and, although these ...
In order to apply widely the superconductivity technology to electric power equipments, the development and evaluation on the AC superconducting cables have been conducted in the Central Research Institute of Electric Power Industry. The superconducting c...
This lecture discusses the physics of ac losses in type-II superconductors and in multifilamentary superconducting-normal composite conductors. As an introduction, the ac eddy-current losses in a homogeneous normal conducting cylindrical specimen subjected to an alternating applied magnetic field are briefly ...
Cr-doped Ni�Zn ferrite nanoparticles having the general formula Ni0.5Zn0.5CrxFe2?xO4 (x=0.1, 0.3, 0.5) were prepared by the simplified sol�gel method. The structural and dielectric properties of the samples sintered at 750�5 �C were studied. X-ray diffraction (XRD) patterns confirm the single-phase spinel structure of the prepared samples. The crystallite size ...
In this work, a tin oxide film was prepared on a silicon wafer. It has exhibited the typical behaviour of a metal-oxide-semiconductor (MOS) structure. This MOS structure was stressed with 60Co-? radiation in the total dose range of 0 500 kGy at room temperature. The effects of the 60Co gamma radiation on the following properties of Au/SnO2/n-Si (MOS) structures, have been ...
ac losses of superconducting solenoidal coils were investigated with a calorimetric method while applying a current or uniform magnetic field of 50 Hz with a sinusoidal wave form. The peak value of the ac current was varied from 0 to 15 rms A and that of the ac magnetic field from 0 to 0.02 T. These experimental ...
The catalytic activity of the CoAcAc)/sub 2/-Et/sub 2/Al(AcAc) system in the hydrogenation of styrene and benzene has been studied and compared to the Co(AcAc)/sub 2/-AlEt/sub 3/ catalytic system. It is shown that the use of Et/sub 2/Al(AcAc) leads to a reduction of catalytic activity toward the hydrogenation of ...
Carbon is an important support for heterogeneous catalysts, such as platinum supported on activated carbon (AC). An important property of these catalysts is that they decompose upon heating in air. Consequently, Pt/AC catalysts can be used in applications requiring rapid decomposition of a material, leaving little residue. This report ...
AC losses in a superconductor strip are numerically evaluated by means of a finite element method formulated with a current vector potential. The expressions of AC losses in an infinite slab that corresponds to a simple model of infinitely stacked strips are also derived theoretically. It is assumed that the ...
A report is given of calorimetric measurements of the ac losses of a small superconducting coil wound from a filament superconductor designed for low ac losses (filament phi = 8 $mu$, number of filaments 1045, CuNi barriers). The coil was pulsed with a maximum dB/dt = 480 kG/s. Further the ...
This study investigated the combined function of the Autographa californica multiple nucleopolyhedrovirus overlapping genes ac16 (BV/ODV-E26, DA26) and ac17. Ac17 is a late gene and the promoter is within the ac16 open reading frame. A double ac16-ac17 knockout virus was ...
The final goal of the program is to establish standard measurement practices and a standard reference material for calibration of apparatus. In this paper the authors discuss a comparison of several techniques for measuring ac losses in superconductors. The techniques are divided into either a calorimetric or electronic type.
It is demonstrated for the first time that a relatively large cryostable superconducting coil can be pulsed with relatively low ac losses at high ramping rates. The low ac losses with limited current sharing have been achieved by insulating the surface of...
The objective of the study is to estimate the probability of failure of the battery system of a nuclear power plant due to loss of ventilation in the battery room during AC blackout. This is part of the more general problem of the interaction between non-...
Nov 24, 2008 ... In a NASA SBIR Phase I and Phase II program we want to develop low AC loss MgB2 superconductors for the stators of synchronous motors or ...
An improved electronic method for measuring ac losses in superconducting cables of lengths from 1m to 10m has been developed and is described. This method compensates for phase shifts in the measuring circuit elements and for imbalance of the difference a...
Energy dissipation, which is also called AC loss, of a composite multifilamentary superconducting wire is one of the most fundamental concerns in building a stable superconducting magnet. Characterization and reduction of AC losses are especially importan...
The measurement of ac losses in superconducting cables by calorimetric means is necessary as a verification of electronic measurements on short high-current models and because the present method of electronic measurement is not applicable to longer cables...
A calorimeter has been developed to measure the total core loss in small samples of magnetic materials which are not suited to conventional measurement techniques. The method is similar to the helium boil-off calorimeter used in some cases to measure ac l...
AC losses in full length and 1.5 m model SSC collider dipoles were successfully measured by the direct observation of energy flow into and out of magnets during a ramp cycle. The measurement was performed by using two double-integrating type digital volt ...
Since 1995 Southwire Company and Oak Ridge National Laboratory (ORNL) have jointly designed, built, and tested nine, l-m long, high temperature superconducting (HTS) transmission cable prototypes. This paper summarizes the AC loss measurements of five of ...
A new cryostat cooled by a closed-cycle Cryomech GB-37 cryocooler for superconductor measurements at temperatures down to 20 K is described. The sample is conductively coupled to the cold stage so as to minimize vibration and thermal stresses. AC losses h...
Thin chalcogenide films of Bi30 Se(70-x) Tex (x=35, 40, and 45 at%), with a thickness of about 200 nm, have been prepared by the thermal evaporation technique. The physical properties that have been studied are: the density (d), the heat of atomisation (Hs), the average coordination number (Z), and the number of lone pair bonds. The AC conductivity ...
The temperature rise of NiFe2O4 nanoparticles having diameters of 242 and 7.7 nm was measured. The results of the measurement were analyzed by comparing the areas of the hysteresis loops in order to clarify the mechanism of heat dissipation in the samples. The hysteresis loops were obtained by applying both ac and dc magnetic fields. It was found that the contribution of ...
From the time constant and the hysteresis loss measurements of the subcables, it is estimated that approximately 60% of the ac losses of the ANL 3.3 MJ coil at 6 T/s of the central field are due to the losses within the 19-strand subcable itself. The remaining 40% of the losses seem to come ...
It was theoretically confirmed that improvement of superconducting-coil performance can be obtained by making optimum use of multifilamentary tapes with high aspect-ratio cross-sections. Superconducting tapes, such as NbTi and MgB2 multifilamentary tapes, are known to have anisotropic electromagnetic properties, i.e., critical current densities and ac ...
... Descriptors : *ELECTROOSMOSIS, MECHANICAL PROPERTIES, POLARIZATION, LIQUIDS, THESES, MICROWAVES, ALTERNATING ...
... PROPERTIES), INTERMETALLIC COMPOUNDS, MAGNETIC MATERIALS, SAMARIUM, YTTERBIUM, PRASEODYMIUM, NIOBIUM ALLOYS ...
... Work has been performed on the theory of ac losses in multifilament superconductors and experiments were made to check the theory. ...
... Abstract : The theory of magnetohydrodynamic power generators is presented. ... sectional area flows; end losses; AC generation; cycle efficiencies ...
An empirical relation is presented which allows simple computation of volume-averaged winding fields
NASA Technical Reports Server (NTRS)
A superconducting tape having reduced AC losses. The tape has a high temperature superconductor layer that is segmented. Disruptive strips, formed in one of the tape substrate, a buffer layer, and the superconducting layer create parallel discontinuities in the superconducting layer that separate the current-carrying elements of the superconducting layer ...
DOEpatents
... Abstract : ;Contents: Uses of low temperatures; Materials; Ac losses in superconductors; Superconducting, Magnets; Energy storage and ...
... X-ray induced ac losses in TFE resins (previously reported) are greatly influenced by the presence of oxygen during sintering. ...
... AC losses and proximity effects in the composites need careful consideration in the evolution of a practical composite conductor. (Author). ...
... HIGH TEMPERATURE, *SINGLE CRYSTALS, *SUPERCONDUCTORS, *ELECTRIC CONDUCTORS, *YTTRIUM BARIUM COPPER OXIDES ...
Cable-in-conduit conductors in pulsed tokamak applications have design requirements imposed by the tokamak operation: typically an operating temperature dependant on the AC losses and pulse time, the field by the tokamak performance and a quench discharge time by the coil voltage limits. The void fraction of helium in the cable is determined by mechanical ...
Ocean color algorithms are based on the parameterization of apparent optical properties as a function of inherent optical properties. WET Labs underwater absorption and attenuation meters (ac-9 and ac-s) measure both the spectral beam attenuation (c (lamb...
This paper describes measured AC losses of NbTi Rutherford type cable when the wide side of the cable is parallel to the field variation. In the case of a Rutherford type cable, the orientation of the cable in the magnetic field is an important factor for the interstrand coupling loss which can be dominant over other ...
The report deals with hysteresis losses at 4 K measured by magnetization and complex magnetic susceptibility. The theoretical and experimental relationships between ac susceptibility and magnetization as functions of dc field were examined in terms of the...
