Hot Extrusion of Ceramics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65963/1/j.1151-2916.1992.tb07206.x.pd

Entsorgung von Reststoffen am Beispiel von Eindampfkristallisat einer Sickerwasser-Reinigungsanlage

Neue rechtliche Grundlagen zur Reinigung von Deponiesickerwaessern, die mit den Aenderungen des Wasserhaushaltsgesetzes, des Abwasserabgabengesetzes und der Abwasserherkunftsverordnung in Kraft traten, fuehrten zur Entwicklung und Anwendung verbesserter Reinigungsverfahren. Mittlerweile gehoeren eine Reihe von Verfahren, unter anderem die Eindampf- und Stripptechnik, zum Stand der Technik der Sickerwasserreinigung. Weitgehend ungeloest ist die Frage der Entsorgung der bei diesen Reinigungsverfahren anfallenden Reststoffe. Bisher werden diese mit Schadstoffen belasteten Rueckstaende, wie Klaerschlaemme oder Faellprodukte, deponiert oder verbrannt. Auch bei der Sickerwassereindampfung fallen Reststoffe, insbesondere das wasserloesliche Eindampfkristallisat, an. Um einer Problemverlagerung von der Abwasser- auf die Abfallseite entgegenzuwirken, wurden im Rahmen dieser Arbeit Entsorgungsalternativen fuer die Eindampfreststoffe untersucht. (orig./EF)Amendments to the Federal Water Act, the Federal Waste Water Charges Act, and the Ordinance On the Origin of Waste Waters have created a new legal basis for the purification of seepage waters from landfills. Meanwhile there are a whole number of techniques, among them evaporation and stripping, that deserve the label state of the art in seepage water purification. However, the problem of disposing the residues arising in these purification processes is still largely consolved. Until now the contaminated residues, such as sewage sludge or deposits, have been landfilled or incinerated. Evaporation of sewage waters also leaves residues, notably water-soluble crystallisate. The present paper examines alternatives for the disposal of residues from evaporation as means of counteracting the current tendency to shift the problem from wastewater to solid wastes management. (orig./EF)SIGLEAvailable from TIB Hannover: RA 2036(116)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Study of metal distributions in YBa2Cu3O7-x/Ag2O composites

The micro proton-induced x-ray emission technique has been used to study the elemental distribution profiles of high- composites on varying the content. Measurements revealed that Ag agglomeration starts to appear in samples with , becoming prominent at 50 wt%. These results are further supported by x-ray diffraction (XRD) measurements performed on the same samples. The XRD results identified a crystalline Ag phase to be present in all of the samples (7-50 wt% ), a crystalline phase in the 25 and 50 wt% samples and no evidence for Ag replacing Cu or orthogonal-to-tetragonal transformatio

Magnetization and Critical Currents of Bi-Sr-Ca-Cu-O and Ba 2YCu3O7 Superconductors

We have measured the critical currrent density Jc as a function of temperature for a Bi-Sr-Ca-Cu-O sample containing a substantial fraction of a phase with Tc≊110 K and for a Ba2YCu 3O7 sample (TTc≊92 K). The behavior of Jc was deduced from magnetization measurements. For both samples the magnetization at fixed temperature and field decayed logarithmically with time. The values of Jc so derived, allowing for the decay to occur, went to zero for temperatures above 35 K for the Bi-Sr-Ca-Cu-O ceramic and to zero above 70 K for the Ba2YCu3O7 sample. These values are substantially lower than those deduced from dynamic M-H loops

Wissenschaftliche Begleitung des Vorhabens 'Eindampfanlage zur Behandlung von Deponiesickerwaessern beim Zweckverband Sondermuellplaetze Mittelfranken (ZVSMM) Abschlussbericht

Available from TIB Hannover: RN 5905(2268) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Large Magnetic Hysteresis in a Melt-Textured Y-Ba-Cu-O Superconductor

Melt-textured YBa2Cu3O7-δ superconductor with a long and well-aligned grain structure is shown to exhibit magnetic hysteresis at 77 K which is the largest ever reported for bulk polycrystalline Y-Ba-Cu-O. The large ΔM resulted in a magnet-like behavior as well as a strong suspension phenomenon. It is shown, contrary to the previous reports, that the suspension behavior observed in Y-Ba-Cu-O is a generic consequence of large grain size, and not due to the presence of Ag oxide or Ag particles. There appears to be no substantial enhancement in flux pinning and Jc by these particles. Comparisons of magnetization behavior in various YBa2Cu3O7-δ samples (polycrystals, silver-oxide doped, melt-textured, and single crystals) indicated that for applied fields substantially larger than Hc1 the current flow that gives rise to the observed magnetization is intragranular. The pinning force and hence the critical current is roughly the same [J c (magn)∼104 A/cm2] within a factor of ∼2 regardless of grain size, grain boundary configuration, presence of second phase particles, or increased dislocation and twin densities