60 Matching Results

Search Results

Advanced search parameters have been applied.

in creator/contributor: "Poeppel, R. B."

open access

Sintering of Bulk High - Tc Superconductors: Bi-Sr-Ca-Cu-O

Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (2212) and (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (2223) superconductors have orthorhombic crystal structures. They form platelike grains that at high temperatures grow primarily in the a-b planes and not in the c direction. The diffusional properties of Bi-Sr-Ca-Cu-O superconductors are so anisotropic that 2212 and 2223 cannot, in general, be densified by solid-state sintering. Improved densification can be achieved by application of pressure or… more

Date: May 1, 1992

Creator: Goretta, K. C.; Lanagan, M. T.; Kaufman, D. Y.; Biondo, A. C.; Wu, C. T.; Loomans, M. E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Biaxial Creep Behavior of Ribbed GCFR Cladding at 650 degrees C in Nominally Pure Helium (99. 99%)

Biaxial creep-rupture tests were conducted on 12 prototypic GCFR fuel-cladding specimens at 650 deg C and a nominal hoop stress of 241.3 MPa. All test specimens were fabricated from 20% cold-worked Type 316 stainless steel tubes that were ribbed on the outer surface by mechanical grinding or electro-chemical etching. Test variables included specimen length and the presence or absence of weld-reinforcing end collars.

Date: November 1977

Creator: Yaggee, F. L.; Purohit, A.; Grajek, W. J. & Poeppel, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Use of Krypton-85 for the Detection of Pinhole Failures in GCFR Cladding

Radioactive krypton-85 is used as a tracer to detect pinhole failures in GCFR cladding. High-purity helium (99.99% pure) that contains 0.3 ppm krypton-85 is used to pressurize the tubular test specimens, and a Geiger-Mueller counter is used to detect the krypton-85 in the helium environmental gas as it leaves the test chamber. Under the least favorable conditions of temperature and specimen pressure, it is estimated that the smallest pinhole failure that could be detected within 60 sec would ha… more

Date: May 1976

Creator: Yaggee, F. L.; Purohit, A. & Poeppel, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: January-March 1984

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes activitiesdirected toward seeking alternative cathode materials to NiO for molten carbonate fuel cells.

Date: January 1985

Creator: Pierce, Robert Dean; Baumert, B.; Claar, T. D.; Fousek, R. J.; Huang, H. S.; Kaun, T. D. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: April-June 1984

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). These efforts have been directed toward seeking alternative cathode materials to NiO for molten carbonate fuel cells. Particular emphasis has been placed on studying the relationship between synthesis conditions and the resistivity of doped and undoped LiFeO2 and Li2 MnO3 and on achieving a better understanding of the crystalline defect structures of the thermodynamically stable phases.

Date: November 1984

Creator: Pierce, Robert Dean; Claar, T. D.; Dees, D. W.; Fousek, R. J.; Kaun, T. D.; Kucera, C. H. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Neutron-Induced Helium Implantation in GCFR Cladding

The neutron-induced implantation of helium atoms on the exterior surfaces of the cladding of a prototypic gas-cooled fast reactor (GCFR) has been investigated analytically. A flux of recoil helium particles as high as 4.2 x 10¹⁰ He/cm sq.s at the cladding surface has been calculated at the peak power location in the core of a 300-MWe GCFR. The calculated profile of the helium implantation rates indicates that although some helium is implanted as deep as 20 microns, more than 99% of helium parti… more

Date: October 1980

Creator: Yamada, H.; Poeppel, R. B. & Sevy, R. H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Evaluation of Ceramic Refractories for Slagging Gasifiers : Summary of Progress to Date

Commercial refractories were tested for up to 500 h in both basic and acidic slags. The slag compositions typify those expected in slagging coal gasifiers. The slag temperatures ranged up to 1600 degrees C. Compositions tested have included silicon carbides, chrome-alumina-magnesia spinels, and alumina and magnesia-based refractories with various amounts of chromia and silica. In some tests, the cold faces were water cooled. With water cooling, the silicon carbides showed virtually no attack af… more

Date: September 1978

Creator: Kennedy, C. R.; Swaroop, R.; Jones, D. J.; Fousek, R. J.; Poeppel, R. B. & Stahl, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: April-June 1979

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving the components of moltencarbonate-electrolyte fuel cells operated at temperatures near 925 K.

Date: November 1979

Creator: Pierce, R. D.; Finn, P. A.; Kinoshita, K.; Kucera, G. H.; Poeppel, R. B.; Singh, R. N. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: July-September 1979

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving components of the molten carbonate fuel cells operated at temperatures near 925 K.

Date: February 1980

Creator: Pierce, R. D.; Kinoshita, K.; Kucera, G. H.; Poeppel, R. B.; Sim, J. W. & Singh, R. N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: October-December 1979

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving components of molten carbonate fuel cells and have included operation of 10-cm square cells.

Date: May 1980

Creator: Pierce, R. D.; Kucera, G. H.; Kupperman, D. S.; Poeppel, R. B.; Sim, J. W.; Singh, R. N. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: January-March 1980

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving components of molten carbonate fuel cells and have included operation of 10-cm square cells.

Date: September 1980

Creator: Pierce, R. D.; Arons, R. M.; Fraioli, A. V.; Kucera, G. H.; Poeppel, R. B.; Sim, J. W. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: April-June 1980

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving components of molten carbonate fuel cells and have included operation of a 10-cm square cell.

Date: November 1980

Creator: Pierce, R. D.; Arons, R. M.; Dusek, J. T.; Fraioli, A. V.; Kucera, G. H.; Poeppel, R. B. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Fuel Cell Development Progress Report: July-September 1980

Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward (1) investigating alternative concepts for components of molten carbonate fuel cell stacks and (2) improving our understanding of component behavior.

Date: July 1981

Creator: Pierce, R. D.; Arons, R. M.; Dusek, J. T.; Fraioli, A. V.; Kucera, G. H.; Poeppel, R. B. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Atmosphere control during preparation of YBa sub 2 Cu sub 3 O sub 7- x magnet windings

Large coils of YBa{sub 2}Cu{sub 3}O{sub 7-x} can be fired successfully if the furnace atmosphere is carefully controlled. Organics added during processing produce CO{sub 2} during the initial portions of the firing schedule. Transmission electron microscopy of material fired in atmospheres containing various levels of CO{sub 2} clearly shows the extent of grain boundary degradation caused by CO{sub 2}. Coils with acceptable critical current density can be produced if the rate of CO{sub 2} remov… more

Date: October 1, 1990

Creator: Poeppel, R. B.; Dorris, S. E.; Picciolo, J. J.; Balachandran, U.; Lanagan, M. T.; Zhang, C. Z. et al.

Item Type: Article

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

open access

Characterization of hot isostatically pressed Bi-Sr-Ca-Cu-O as a function of consolidation variables

Fully dense, bulk Bi{sub 2}Sr{sub 1.7}CaCu{sub 2}O{sub x} (2212) superconductor pellets were made by hot isostatic pressing in an inert atmosphere. Electron microscopy revealed that rotation and bending of the platelike 2212 grains were responsible for much of the densification. Under processing conditions of 825{degrees}C and 105 MPa, dense pellets were obtained in 15 min. Many dislocations, planar faults, and, perhaps, intergrowths of the Bi{sub 2}Sr{sub 2}CuO{sub x} phase were produced durin… more

Date: November 1, 1991

Creator: Goretta, K. C.; Miller, D. J.; Poeppel, R. B. & Nash, A. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Sodium Heat Engine Development Program

The Sodium Heat Engine (SHE) is an efficient thermoelectric conversion device which directly generates electricity from a thermally regenerative electrochemical cell that relies on the unique conduction properties of {beta}{double prime}-alumina solid electrolyte (BASE). Laboratory models of a variety of SHE devices have demonstrated the feasibility and efficiency of the system, engineering development of large prototype devices has been slowed by a series of materials and fabrication problems.… more

Date: January 1, 1992

Creator: Singh, J. P.; Kupperman, D. S.; Majumdar, S.; Dorris, S.; Gopalsami, N.; Dieckman, S. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Control of YBa sub 2 Cu sub 3 O sub 7 minus x degradation during heat treatment

The importance of closely controlling the furnace atmosphere during processing of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) was examined. The stability of YBCO during sintering was studied as a function of CO{sub 2} partial pressure in CO{sub 2}/O{sub 2} gas mixtures. The zero-field critical current density, J{sub c}, decreased with increasing CO{sub 2} partial pressure, and ultimately reached zero, even though Meissner effect measurements showed that the bulk of the samples with zero transport J{su… more

Date: October 1, 1990

Creator: Dorris, S. E.; Poeppel, R. B.; Picciolo, J. J.; Balachandran, U.; Lanagan, M. T.; Zhang, C. Z. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Recent Results in Characterization of Melt-Grown and Quench-Melt- Grown YBCO Superconductors

From the standpoint of applications, melt-grown (MG) and quench-melt-grown (QMG) bulk YBCO superconductors are of considerable interest. In this paper, we studied the intragranular critical current density (J{sub c}), the apparent pinning potential (U{sub o}), and the irreversibility temperature (T{sub irr}) of MG and QMG samples and compared the results to those for conventionally sintered YBCO. A systematic increase in U{sub o} and a slower drop in J{sub c} with temperature indicate a systema… more

Date: February 1, 1992

Creator: Balachandran, U.; Poeppel, R. B. & Gangopadhyay, A. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Processing and Microstructural Development of Ag-clad Bi-Sr-Ca-Cu-O Tapes

Ag-clad Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub x] (2212) and (Bi,Pb)[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub x] (2223) tapes were fabricated by drawing and rolling. Highly textured microstructures and high critical current density values were obtained for each system. However, the heat treatments and phase evolutions for 2212 and 2223 were different. For 2212, nearly phase-pure powder was used, and the heat treatments consisted of partial melting followed by solid-state sintering. For 2223, several … more

Date: October 1, 1992

Creator: Poeppel, R. B.; Goretta, K. C.; Balachandran, U.; Biondo, A. C.; Dorris, S. E.; Hathcox, S. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The FUBR-1B experiment and BEATRIX-I

The objective of this work is to irradiate lithium ceramics in a fast neutron environment to high burnup levels and with large temperature gradients. The first insertion of two subassemblies completed its irradiation in December 1986. This irradiation exposed Li/sub 2/O and LiAlO and LiA102 to not only high temperatures but also large temperature gradients which are expected in fusion blankets. In addition, it included other materials such as Li/sub 2/ZrO/sub 3/, Li/sub 8/ZrO/sub 6/, Li/sub 4/S… more

Date: January 1, 1987

Creator: Hollenberg, G. W.; Knight, R. C.; Pember, L. A.; Johnson, C. E.; Poeppel, R. B. & Yang, L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Practical superconductor development for electrical power applications. Annual report for FY 1993

Development of useful high-critical-temperature 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 technical progress of research and development efforts aimed at producing superconducting components in the Y-Ba-Cu, (Bi,Pb)-Sr-Ca-Cu,(Tl,Pb, Bi)-(Ba,Sr)-Ca-Cu, and Hg-Ba-Ca-Cu… more

Date: October 1, 1993

Creator: Poeppel, R. B.; Goretta, K. C. & Askew, T. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Synthesis of rare-earth-based oxides for the ceramic industry: From laboratory to pilot plant

A wide variety of compounds, e.g., superconductors, chromites, and manganites, have been synthesized by spray drying a mixture of salts or a combination of salts and sols in a flash dryer. The process allows for good control of stoichiometry, morphology, particle size, and surface area. Appropriate particle-growth and synthesis heat treatments of these fine powders were performed. The resultant powders were evaluated for possible applications in fuel cells and superconductors. The processes hav… more

Date: November 1, 1991

Creator: Balachandran, U.; Dorris, S. E.; Lanagan, M. T.; Poeppel, R. B.; Tourre, J. M. & Golowski, J. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characterization of hot isostatically pressed Bi-Sr-Ca-Cu-O as a function of consolidation variables

Date: November 1, 1991

Creator: Goretta, K. C.; Miller, D. J.; Poeppel, R. B. & Nash, A. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department