Zur Schlußreinigung konzentrierter Zuckerfabrikabwässer

The most important measure is that the freshwater demand of 0.5 m³ per t beet processing is strictly kept to or fallen below, to which a catalogue of measures with ten points is presented. The wastewaters which cannot be used again have to be stored prior to the final purification in order to compensate for quantities and concentrations, aerated storage ponds being successful for small sugar factories as the purification technology. For this, three cases are described as examples: supplementary equipment of two anaerobic ponds with a rod-roll aeration, by which within two months (May to July) the BOD₃ is reduced from 1,200 to 11 mg/l. The aeration of a pond of 12.5 ha (370,000 … 500,000 m³) by means of a centrifugal aerator (45 kW) does not lead to completely aerobic conditions: Accumulation up to 350 t BOD₅, 200 t organic acids at a reduction of 100 t sulphate, 45 t of which being converted via sulphides by photoautotrophic sulphur bacteria. This combination of anaerobic and aerobic processes is very economical. At aeration with ca. 1 W/m³ in the third case in summer there are achieved wastewater loads which are of a receiving-water quality.     

Raman scattering study of the high-temperature vibrational properties and stability of CaGeO3 perovskite

The vibrational properties of metastable Ca-GeO₃ perovskite are investigated as a function of temperature using Raman scattering. Mode-assignments are derived from polarized spectra of optically oriented single crystals. Neither symmetry-breaking structural transformations nor soft-mode behavior is revealed in the Raman spectra between room temperature and 650° C. Only a small decrease in the local static octahedral tilt angles can be inferred from the Raman data over this temperature range. A Landau extrapolation of the lowest frequency A_g modes suggests that these modes become critical near 2000° C, a temperature that is above the extrapolated zero pressure melting point.     

An evaluation of the ductility reduction factor q in the 1976 regulations for the federal district of mexico

The reduction of the spectral accelerations to account for inelastic response of structures as given by the 1976 Regulations for the Federal District of Mexico is evaluated relative to the records obtained at the Secretaria de Communicaciones y Transportes (SCT) during the September 19, 1985 Mexico earthquake. It is concluded that the 1976 Regulations do not treat all types of structural systems equally. On a relative basis the 1976 Regulations provide less protection for those structures designed to larger values of ductility factors. This could have contributed, together with other characteristics of the ground motions and construction practices, to the heavy damage of highrise buildings in Mexico City.     

Expert judgment and climate forecasting: A methodological critique of “climate change to the year 2000”

The National Defense University's study of climate change to the year 2000 was based largely on the judgments of the members of two expert panels. Although the study has been widely distributed and apparently read by policy makers in the U.S. and abroad, the method of eliciting and analyzing expert judgment has not been critically reviewed. This paper uses the literature on judgment and subjective probability to evaluate the expert judgment methods used in the study.The National Center for Atmospheric Research is sponsored by the National Science Foundation.     

Two-step deglaciation: 14C-Dated high-resolution δ18O records from the tropical Atlantic Ocean

Eight box cores from the tropical Atlantic were studied in detail with regard to foraminiferal oxygen isotopes, radiocarbon, and Globorotalia menardii abundance. A standard Atlantic oxygen-isotope signal was reconstructed for the last 20,000 yr. It is quite similar to the west-equatorial Pacific signal published previously. Deglaciation is seen to occur in two steps which are separated by a pause. Onset of deglaciation is after 15,000 yr B.P. The pause is centered between 11,000 and 12,000 yr B.P., but may be correlative with the Younger Dryas (10,500 yr B.P.) if allowance is made for a scale shift due to mixing processes on the sea floor. Step 2 is centered near 10,000 yr B.P. and is followed by a brief excursion toward light oxygen values. This excursion (the M event) may correlate with the Gulf of Mexico meltwater spike.