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in creator/contributor: "Hull, J. R."

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Practical superconductor development for electrical power applications annual report for FY 1998.

Development of useful high-T{sub c} superconductors requires synthesis of superconducting compounds; fabrication of wires, tapes, and films from these compounds; production of composite structures that incorporate stabilizers or insulators; and design and testing of efficient components. This report describes FY 1998 technical progress of research and development efforts aimed at producing superconducting components in the Bi-(Pb)-Sr-Ca-Cu and Y-Ba-Cu oxide systems. Topics discussed are synthes… more

Date: January 27, 1999

Creator: Askew, T. R.; Balachandran, U.; Cha, Y. S.; Dorris, S. E.; Dusek, J. T.; Emerson, J. E. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Practical superconductor development for electrical power applications - annual report for FY 2003.

Most large-scale applications of high-critical-temperature superconductors will require conductors that can carry large currents in the presence of applied magnetic fields. This report describes progress at Argonne National Laboratory (ANL) in the research and development of practical superconducting components and devices. These efforts primarily focus on the use of Y-Ba-Cu-O system in second-generation conductors, but they also include investigations of Bi-Pb-Sr-Ca-Cu-O systems for use in fir… more

Date: October 18, 2004

Creator: Balachandran, U.; Baurceanu, R.; Clauss, H.; Dorris, S. E.; Emerson, J. E.; Erck, R. A et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Practical superconductor development for electrical power applications - annual report for FY 2000.

Most large-scale high-critical-temperature superconductor applications require wires or tapes that an carry high currents in applied magnetic fields. This report describes technical progress of research and development efforts aimed at producing superconducting components and devices in the Y-Ba-Cu-O and Bi-(Pb)-Sr-Ca-Cu-O systems. Topics discussed are formation of first- and second-generation composite conductors, characterization of structures and superconducting and mechanical properties, mo… more

Date: January 25, 2001

Creator: Balachandran, U.; Cha, Y. S.; Dorris, S. E.; Dusek, J. T.; Emerson, J. E.; Fisher, B. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Electromagnetic continuous casting project: Final report

This report describes the work on development of an electromagnetic casting process for steel, which was carried out at Argonne National Laboratory between January 1985 and December 1987. This effort was concerned principally with analysis and design work on magnet technology, liquid metal feed system, coolant system, and sensors and process controllers. Experimentation primarily involved (1) electromagnetic studies to determine the conditions and controlling parameters for stable levitation an… more

Date: October 1, 1988

Creator: Battles, J. E.; Rote, D. M.; Misra, B.; Praeg, W. F.; Hull, J. R.; Turner, L. R. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Practical superconductor development for electrical power applications: annual report for FY 2002.

Most large-scale applications of high-critical-temperature superconductors will require conductors that can carry large currents in the presence of applied magnetic fields. This report describes progress at Argonne National Laboratory (ANL) in the research and development of practical superconducting components and devices using the Y-Ba-Cu-O and Bi-Pb-Sr-Ca-Cu-O systems. Results are presented in the areas of fabrication of second- and first-generation composite conductors, characterization of … more

Date: April 9, 2003

Creator: Baurceanu, R.; Cha, Y. S.; Dorris, S. E.; Emerson, J. E.; Erck, R. A.; Fisher, B. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Practical superconductor development for electrical power applications : annual report for FY 2001.

Most large-scale applications of high-critical-temperature superconductors will require wires or tapes that can carry large current in applied magnetic fields. This report describes research and development efforts at Argonne National Laboratory (ANL) aimed at producing practical superconducting components and devices using the Y-Ba-Cu-O and Bi-(Pb)-Sr-Ca-Cu-O systems. Topics discussed include various methods of forming second- and first-generation composite conductors, characterization of thei… more

Date: May 2, 2002

Creator: Cha, Y. S.; Dorris, S. E.; Dusek, J. T.; Emerson, J. E.; Erck, R. A.; Fisher, B. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The effect of processing parameters during heat treatment of bulk high- Tc superconductors

Plastic extrusion is a promising method for producing the long lengths of high-{Tc} superconductor that will be necessary to meet many potential applications. A crucial phase of the extrusion method is removal of organic constituents. Incomplete removal can leave residual carbon at grain boundaries, which can adversely affect the superconducting properties, whereas excessively rapid removal of the organics can cause the extruded superconductor to disintegrate completely. In this paper, we analy… more

Date: April 1, 1991

Creator: Cha, Y. S.; Dorris, S. E.; Hull, J. R. & Poeppel, R. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The effect of processing parameters during heat treatment of bulk high-{Tc} superconductors

Date: April 1, 1991

Creator: Cha, Y. S.; Dorris, S. E.; Hull, J. R. & Poeppel, R. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Flux-flow resistivity of three high-temperature superconductors

Results of experiments on flux-flow resistivity (the relationship of voltage to current) of three high-temperature superconductors are described. The superconductors are a melt-cast BSCCO 2212 rod, a single filament BSCCO powder-in-tube (PIT) tape, and a multifilament PIT tape. The flux-flow resistivity of these superconductors was measured at three temperatures: 77 K (saturated liquid nitrogen), 87 K (saturated liquid argon), and 67 K (subcooled liquid nitrogen). Implications of the present re… more

Date: October 1996

Creator: Cha, Y. S.; Evans, D. J.; Hull, J. R. & Seol, S. Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cryostabilization of high-temperature superconducting magnets with subcooled flow in microchannels

Subcooled flow of liquid nitrogen in microchannels is proposed as a means to enhance the stability of a superconducting magnet. Analysis shows high current density or a low stabilizer fraction is obtainable in a cryostable magnet. Increase in stability (using the Stekley criterion) is directly related to coolant velocity and coolant channel aspect ratio, however, there is a corresponding increase in pressure drop of the system. Another constraint is the coolant temperature rise, which is found … more

Date: July 6, 1992

Creator: Cha, Y. S.; Hull, J. R. & Choi, U. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cryostabilization of high-temperature superconducting magnets with subcooled flow in microchannels

Date: July 6, 1992

Creator: Cha, Y. S.; Hull, J. R. & Choi, U. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design of microchannels for cryostabilization of high temperature superconducting magnets

Microchannel cooling using subcooled liquid nitrogen is proposed to cryogenically stabilize high-temperature superconducting magnets. Various design constraints and parameters are identified and summarized. A graphical method is proposed for the design of microchannel systems. This graphical method helps to reduce the amount of work towards achieving optimum design for a specific application because there are a large number of parameters involved in the design of a microchannel system. The prop… more

Date: October 1, 1993

Creator: Cha, Y. S.; Hull, J. R. & Niemann, R. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Apparatus to measure liquid helium boil-off from low-loss superconducting current leads

A low-loss liquid helium dewar was constructed to measure the liquid helium boil-off rate from high-temperature superconducting current leads. The dewar has a measured background heat leakage rate of 12 mW. Equations calculating the heat leakage rate from the measured vapor mass flow rate in liquid helium boil-off experiments are derived. Parameters that affect the experiments, such as density ratio, absolute pressure, and rate of pressure variation, are discussed. This study is important as su… more

Date: June 1, 1995

Creator: Cha, Y. S.; Niemann, R. C. & Hull, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Thermal characteristics of a low-loss liquid-helium dewar

A liquid helium dewar has been designed, fabricated, and operated successfully with a minimum background heat-loss rate of only a few milliwatts. The objective is to provide a facility that can be used to measure relatively low heat-loss rate (1--100 milliwatts) in a liquid helium environment. The experimental system consists mainly of an inner helium reservoir within an outer helium reservoir that is thermally shielded from the room-temperature environment by multiple insulation layers in a va… more

Date: May 1, 1994

Creator: Cha, Y. S.; Niemann, R. C. & Hull, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Liquid helium boil-off measurements of heat leakage from sinter-forged BSCCO current leads under DC and AC conditions

Liquid helium boil-off experiments are conducted to determine the heat leakage rate of a pair of BSCCO 2223 high-temperature superconductor current leads made by sinter forging. The experiments are carried out in both DC and AC conditions and with and without an intermediate heat intercept. Current ranges are from 0-500 A for DC tests and 0-1,000 A{sub rms} for AC tests. The leads are self-cooled. Results show that magnetic hysteresis (AC) losses for both the BSCCO leads and the low-temperature… more

Date: June 1, 1995

Creator: Cha, Y. S.; Niemann, R. C.; Hull, J. R.; Youngdahl, C. A.; Lanagan, M. T.; Nakade, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design, Construction, and Initial Operation of the ANL Research Salt-Gradient Solar Pond

The design consideration of a 1/4 acre research salt-gradient solar pond is described. Experience learned during the construction of the solar pond is presented. Initial operation of the pond indicates that the construction of the pond is sound and no leakage has occurred. The pond began to warm up during March of 1981. The maximum pond temperature reached 63 C at the end of July and it is still rising. All signs indicate that the operation of the well instrumented pond will be a success and th… more

Date: 1981

Creator: Cha, Y. S.; Sha, W. T. & Hull, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Effect of flux flow on current distribution and heat generation in composite superconductors during a thermal disturbance

An analytical investigation of current distribution and heat generation rate in composite superconductors, incorporating the effects of flux flow during disturbances, is carried out. Equations describing current density in the superconductor and the heat generation rate per unit volume of the composite conductor in the current sharing regime are derived. The results show that when the superconductor is in the flux-flow state, the current density and the heat generation rate depend only on a dim… more

Date: September 1, 1994

Creator: Cha, Y.S.; Hull, J.R. & Askew, T.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Critical current density and dissipation in sintered YBCO filaments

Critical current density and dissipation of four sintered YBCO filaments were measured using a continuous DC power supply. Each sample exhibited somewhat different characteristics from the others even though 3 of the 4 samples are from the same batch. The data suggest that it is possible for the YBCO filament to be in a state of stable equilibrium when part of the filament is in the flux-flow state and part of the filament is in the normal state (local hot spots). This behavior may be advantage… more

Date: September 1, 1997

Creator: Cha, Y.S.; Hull, J.R. & Seol, S.Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Computer Modeling of Electromagnetic Edge Containment in Twin-Roll Casting

This paper presents modeling studies of magnetohydrodynamics (MHD) analysis in twin-roll casting. Argonne National Laboratory (ANL) and Inland Steel Company have worked together to develop a 3-D computer model that can predict eddy currents, fluid flows, and liquid metal containment for an electromagnetic (EM) edge containment device. This mathematical model can greatly shorten casting research on the use of EM fields for liquid metal containment and control. It can also optimize the existing c… more

Date: July 1, 1998

Creator: Chang, F. C.; Turner, L. R.; Hull, J. R.; Wang, Y. H. & Blazek, K. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Simulation of fluid flow induced by opposing ac magnetic fields in a continuous casting mold

A numerical simulation was performed for a novel electromagnetic stirring system employing two rotating magnetic fields. The system controls stirring flow in the meniscus region of a continuous casting mold independently from the stirring induced within the remaining volume of the mold by a main electromagnetic stirrer (M-EMS). This control is achieved by applying to the meniscus region an auxiliary electromagnetic field whose direction of rotation is opposite to that of the main magnetic field… more

Date: July 1, 1995

Creator: Chang, F.C.; Hull, J.R. & Beitelman, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Computer modeling of electromagnetic fields and fluid flows for edge containment in continuous casting

A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel for twin-roll casting. The model can optimize the EMD design so it is suitable for application, and minimize expensive, time-consuming full-scale testing. Numerical simulation was performed by coupling a three-dimensional (3-D)… more

Date: February 1, 1996

Creator: Chang, F.C.; Hull, J.R.; Wang, Y.H. & Blazek, K.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mathematical Modeling and Evaluation of Radionuclide Transport Parameters from the ANL Laboratory Analog Program

Computer model simulation is required to evaluate the performance of proposed or future high-level radioactive waste geological repositories. However, the accuracy of a model in predicting the real situation depends on how well the values of the transport properties are prescribed as input parameters. Knowledge of transport parameters is therefore essential. We have modeled ANL's Experiment Analog Program which was designed to simulate long-term radwaste migration process by groundwater flowing… more

Date: July 1984

Creator: Chen, B. C-J.; Hull, J. R.; Seitz, M. G.; Sha, William T.; Shah, V. L. & Soo, S. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Mathematical modeling and evaluation of radionuclide transport parameters from the ANL Laboratory Analog Program

Date: July 1, 1984

Creator: Chen, B.C.J.; Hull, J.R.; Seitz, M.G.; Sha, W.T.; Shah, V.L. & Soo, S.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Comparison of Testing Methods for Latent-Heat-Storage Devices

ASHRAE Standard 94-77, Method of Testing Thermal Storage Devices Based on Thermal Performance, was developed to allow manufacturers of thermal energy storage devices to compare their products in a meaningful way. When Standard 94-77 was used for thermal energy storage products based on latent heat storage, the Standard was found to be inadequate for comparison of these devices. Standard Project Committee SPC 94.1 was established to devise a Standard that would be adequate for comparing latent h… more

Date: February 1983

Creator: Cole, Roger Lynn; Hull, J. R.; Lwin, Y. & Cha, Y. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department