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Found 709 results.

Ozone soundings as a tool for detecting ozone change

Das Projekt "Ozone soundings as a tool for detecting ozone change" wird vom Umweltbundesamt gefördert und von Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung - Institut AWI - Forschungsstelle Potsdam durchgeführt. Objective: 1. To measure the rate and extent of ozone loss both inside the Arctic vortex and at middle latitudes during the winters of 1995-96, 96-97 and 97-98. 2. To follow the ozone destruction as it develops during an individual winter and from one winter to the next. 3. To investigate the structure and duration of laminae episodes. 4. To extend the important record of ozonesonde data obtained during the last four winters. 5. To build a data base of quality controlled ozonesonde data collected since 1988. 6. To provide this and other projects with meteorological analyses and forecasts from ECMWF. General Information: The work programme consists of five work packages: 1. Purchase and distribution of sondes and sonde operation 2. Match campaign and analysis If ozone loss occurs it will be detected by launching sondes from different stations into the same air mass a few days apart. This is achieved by using forecast trajectories. A large number of such matching pairs is needed in order to get a good statistics. It is the aim to investigate the ozone loss both inside the polar vortex and at middle latitudes. Sondes launched in Canada will be used as primary sondes, and the same air mass will be measured by the European stations. 3. Ozone laminae, climatology and trends 3.1 Mean ozone field 3.2 Ozone versus potential vorticity (PV) The effects of dynamics will be isolated from chemical effects by considering the relative evolution of ozone and PV. 3.3 Extension to subtropical latitudes This activity will address changes in the ozone distribution caused by dynamical changes, which can then be linked to the effects seen at middle latitudes. 3.4 Ozone trends on isentropic levels The temporal evolution of the ozone mixing ratio at isentropic surfaces will be studied. Diabatic descent will be accounted for. Data will be sorted according to the PV values at the sounding site. 3.5 Measurement of ozone laminae A newly improved ozone lidar will measure ozone from 4 to 18 km. It will be used to measure the passage of ozone laminae over Aberystwyth, in order to determine the typical along-flow scales of these features. 4. Quality control and homogeneous ozonesonde data base Ozonesonde data will be subject to daily quality control. A comparison of how the different stations convert raw data to geophysical data will be carried out before winter 1996-97. Common sounding instructions will be distributed to the stations. After the campaign the post mission quality control will verify the correctness of the final data in close collaboration with the station PIs. An archive of quality controlled data from 1988-1998 will be made and disseminated on CD-ROM. 5. Data centre and ECMWF data Ozonesonde data will be collected from the sounding stations in near real time. Data from ECMWF will be collected for use by OSDOC and some other projects. Prime Contractor: Norwegian Institute for Air Research; Kjeller; Norway.

On-line zinc analysis of hot converter exhaust gas

Das Projekt "On-line zinc analysis of hot converter exhaust gas" wird vom Umweltbundesamt gefördert und von Krupp Hoesch Stahl durchgeführt. General Information: The growing use of zinc-coated steel sheet in a variety of sectors (motor industry, consumer durables and construction industry) has led to an increase in the zinc content of home scrap, a large proportion of which is recycled in L-D steelworks. From a metallurgical point of view, the Zn coating of the scrap does not interfere with the steel production process, nor does it normally affect product quality. However, the zinc does accumulate in the process dusts. Despite their high iron content, typically around 60 per cent, these dusts cannot be recycled in the sintering plant or the blast furnace because of the zinc load without additional, usually complicated processing stages, above all owing to the risk of scaling in the blast furnace. On the other hand, the typical zinc content of these dusts of 2 per cent is too low to be recycled in zinc foundries. From the purely economic point of view, this currently requires Zn concentrations of well above 30 per cent. If the dusts and slurries from the waste gas cleaning system of an L-D converter are to be recycled internally, the zinc load must be reduced to a level that will not damage the blast furnace. The main source of the zinc in the dusts from waste gas purification is the scrap used in the converter, the Zn content of which can vary considerably. Some types of scrap are practically zinc-free, e.g. the uncoated process scrap or comparable new scrap. However, a large proportion of the scrap used, with the exception of the internal scrap arising in the finishing plants, has an unknown zinc content. This is particularly true of capital scrap. A knowledge of the Zn load per converter batch would basically make it possible to identify and hive off dusts and slurries suitable for the blast furnace. This would permit separation of recyclable and non-recyclable dust fractions, which would reduce the amount of material to be land filled or processed separately. While it is in principle technically possible to study the Zn content of metal in the scrap industry, the information would not normally be very useful, as it is practically impossible to take a representative sample in normal scrap handling practice. A way must therefore be found of reliably quantifying the zinc stream from the converter, in order to be able to determine the zinc load of the dusts and slurries from waste gas purification. The evaporation behaviour of zinc can be harnessed for this purpose, as dusts highly contaminated with zinc are driven off as soon as pig iron is poured over the scrap, or during the following first minutes of blowing, so that a reliable zinc analysis should be possible. The task is to develop a method of detecting zinc in the flue dust of the converter deduster. The objective is to measure the Zn content above a threshold value reliably throughout the process, in order to use this information to separate low-zinc from high-zinc dust fractions.

Spurenelementgehalt der Saale, ein Vergleich der Analysen von 1950 und 1996

Das Projekt "Spurenelementgehalt der Saale, ein Vergleich der Analysen von 1950 und 1996" wird vom Umweltbundesamt gefördert und von Universität Jena, Institut für Ökologie, Arbeitsgruppe Limnologie durchgeführt. Ziel der Untersuchung war, die Veraenderung des Saalewassers unter besonderer Beruecksichtigung der Spurenelemente, ueber die Zeitspanne von etwa 40 Jahren zu erfassen. Mit 12 monatlich entnommenen Proben im Jahr, entsprechend den Untersuchungen von F. Heide in den 50iger Jahren, wurden 28 (geb. 33) Elemente in geloester und an Schwebstoffe gebundener Form untersucht. Gegenueber 1950 wurden analysiert: - geringere Werte fuer Al, Pb, Fe, AS, Ba, Zn; - vergleichbare Werte fuer F, Cr, Ti, Mn, Co, Si, Li, Sr, Na, K, Ca, U; - hoehere Werte fuer Mg, B, Rb, Ni, Sc, Cd. Auffallend veraendert hat sich der Gehalt an B (Waschmittel) und Fe, Al, Zn wahrscheinlich durch Sorption und Komplexbildung, Ca, Mg (saure Regen?).

Use of a new type of anthracite curner and boiler in a power station

Das Projekt "Use of a new type of anthracite curner and boiler in a power station" wird vom Umweltbundesamt gefördert und von Sophia-Jacoba GmbH, Steinkohlenbergwerk durchgeführt. Objective: To demonstrate the use of an innovative, low pollutant burner of low volability anthracite, in a power station, in combination with a boiler system linked to a coal mine, thus solving the problems of mineral oil substitutes, use of low volability coal, SO2 separation, nitrogen removal, adjustability and economy. General Information: The burner design, divided into pre-burner and main burner, means that the ignition and burning of the coal dust can be maintained without brick-lined burner walls and heated combustion air. Due to the type of air passage and course of combustion, the combusted ash is drawn off dry; the boiler can be dimensioned without the need to take waste gas loading into account. The direction of the air and combustion allows 'the cold' combustion with low NOx concentrations. By the addition of lime dust, waste gases are desulphurised in the burner. After grinding to dust, fine coal is passed from storage silos to 7 burners then passed for pre-burning where it is ignited using propane gas; this is gradually decreased (after warming the pre -burner) as the coal dust passes in. This, then, continues to burn by recirculation of hot exhaust gases and continuous glowing coal-dust residue at the end of the pre -burner/start of the main burner. Air supply is via nozzles at the end of the burner which allows combustion control, termination and separation of air particles for easy disposal. To reduce SO2, lime dust is added in the main burner. Waste gas is filtered prior to emission to the atmosphere. The advantage of low-volability coals are: - easier storage (fewer volatile components); - easier transport by road, without need for special measures; - no danger from explosion since anthracite dust is not self -igniting, and there is no risk to groundwater. It is comparable to gas or oil-fired systems from the viewpoint of handling, storage and burning. Achievements: The burners were able to ignite and burn low volatile coal in the combustion chambers of this unit, however, an operation of the boiler was not possible. Reasons were the temperature level, flow behaviour, heat expansion and instabilities of the feed water flow. Thus the project failed. The calculation of expected and actual simple payback was originally based on a comparison with oil burning installations. Based on today's oil price a re-evaluation does not turn out favourable for coal. Furthermore, a realistic comparison cannot be conducted due to the defective boiler.

Der Einfluss von NOx-Emissionen des Flugzeugs auf die Atmosphaere bei Flughoehen von 8-15 km (AERONOX)

Das Projekt "Der Einfluss von NOx-Emissionen des Flugzeugs auf die Atmosphaere bei Flughoehen von 8-15 km (AERONOX)" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Physik der Atmosphäre Oberpfaffenhofen durchgeführt. The AERONOX project investigated the emissions of nitrogen (NOx) from aircraft engines and global air traffic at cruising altitudes, the resultant increase in Nox concentrations, and the effects on the composition of the atmosphere, in particular with respect to ozone formation in the upper troposphere and lower stratosphere. The project was structured into three subprojects: Engine exhaust emissions, physics and chemistry in the aircraft wake, and global atmospheric model simulations. A complementary program of work by aviation experts has provided detailed information on air traffic data which was combined with data on aircraft performance and emissions to produce a global emissions inventory. The work resulted in improved predictive equations to determine Nox emission measurements on two engines in cruise conditions. This information was combined with a traffic database to provide a new global Nox emissions inventory. It was found that only minor chemical changes occur during the vortex regime of the emission plume; however this result does not exclude the possibility of further changes in the dispersion phase. A variety of global models was set up to investigate the changes in NOx concentrations and photochemistry. Although aviation contributes only a small proportion (about 3 per cent) of the total global NOx from the anthropogenic sorces, the models show that aviation contributes a large fraction to the concentrations of NOx in the upper troposphere, in particular north of 30 N.

Messungen des SO2-Gehaltes der Luft

Das Projekt "Messungen des SO2-Gehaltes der Luft" wird vom Umweltbundesamt gefördert und von Forstliche Versuchs- und Forschungsanstalt Baden-Württemberg durchgeführt.

Measurements of fission products in the experiments mol 7C/6 and mol 7C/7

Das Projekt "Measurements of fission products in the experiments mol 7C/6 and mol 7C/7" wird vom Umweltbundesamt gefördert und von Forschungszentrum Karlsruhe GmbH Technik und Umwelt durchgeführt. Objective: During core melt-down accidents, significant fractions of the fission product inventory can be released from the molten fuel to the sodium, and subsequent to vessel failure; a further release of fission products from the evaporating sodium-pool to the atmosphere will occur. The physical processes which occur in the mol 7c experiments, melting of the fuel in presence of sodium, being comparable with a real accident, interesting and important information can be obtained with respect to the source term problem of core melt-down accidents. Measurement of the activity concentration of the different fission products in the sodium and relating it to the mass of disrupted and molten fuel could provide nuclide-specific transfer factors. The unique features offered by the mol 7c experiments (release of radio nuclides from genuine molten LMFBR fuel through sodium vapour and liquid) can be fully utilized with the addition of a fission products measuring device, without interfering with the main objective of the experiment. General information: the upper part of the sodium circuit of the mol 7c in-pile section extends above the reactor top cover. So, fission product activity measurements can be made in front of the expansion tank which forms the upper part of the mol 7c loop. Activity measurements are made with a ge-li detector incorporated in an under water measuring device. This device has been conceived and used for the scanning of LWR fuel elements in the reactor pool. Between the detector and the mol 7c loop a collimator tube is installed. In front of the detector the lead shield around the upper part of the mol 7c loop is provided with a window. A preliminary evaluation of the detection limits of the fission products under theses circumstances gives the following results: - isotopes considered in the evaluation: 18 - isotopes easy to be measured: 8 sr91, i131, i133, ru103, ru105, te132, i134, i135 - isotopes detectable: 6 zr95, y92, y 93, zr97, ba140, nd149 - isotopes not detectable or with interference: 4 y91, te127m, ce144, nd147. The fabrication of the measuring device is in progress and it is scheduled to be available when the mol 7c/6 experiment is being carried out.

Esposure and risk assessment for fine and ultrafine in ambient air

Das Projekt "Esposure and risk assessment for fine and ultrafine in ambient air" wird vom Umweltbundesamt gefördert und von GSF-Forschungszentrum für Umwelt und Gesundheit GmbH - Institut für Epidemiologie durchgeführt. Objective: 1. Compare available particle counters to measure continuously concentrations and size distributions of fine and ultra fine particles in the urban atmosphere. 2. Assess the size distribution and elemental composition of respirable particles in different urban atmospheres in Germany, the Netherlands and Finland. General Information/Expected achievements: The project is expected to produce significant improvements in our understanding on size distributions, intercorrelations, and behaviour of fine and ultra fine particles in urban air in Europe and how to best measure them. This will also enable future studies to address the question, which characteristics (size, number, elemental composition) of respirable particles in ambient air determine their health effects. Methods Particle counters. The German Mobile Aerosol Spectrometer (MAS) consists of two different sensors covering different size ranges. Particles in the size range from 0.01 5m to 0.1 5m are measured using a differential mobility analyzer (DMA, TSI model 3071) in combination with a condensation nucleus counter (CNC, TSI model 3760). Particles in the size range from 0.1 5m up to 3 5m are classified by a laser aerosol spectrometer (LAS, PMS model LAS-X). In the Netherlands, similar equipment as in Germany will be used. Electric Aerosol Spectrometer (EAS) used in Finland is based on the electric measurement principal similar to the principle of EAA model 3030 of TSI, but significantly modified taking into account the needs of atmospheric aerosol studies in urban and rural environment. EAS has an enlarged measurement range from 0.010 5m to 10 5m divided into fractions. All fractions are measured in parallel and simultaneously. Other Measurements In addition to the particle counters, the following measurements will be done: CPC (TSI 3022A), 24-hour samples of PM10 and PM2.5 with impactors, metal composition of PM2.5 filters and continuous monitoring of gaseous pollutants and weather. Comparisons between different particle counters. The particle counters will be compared mainly running them side-by-side in ambient air conditions. Measuring campaign of ambient aerosols During the winter 1996-97, levels, gradients, and elemental composition of fine particles in urban sites in Germany, the Netherlands, and Finland will be determined. In each location, ambient air quality will be monitored at one site representing background urban levels of air pollution. Prime Contractor: National Public Health Institute, Unit of Environmental Epidemiology; Helsinki; Finland.

Mitarbeit an der Umweltprobenbank des Bundes im Jahre 1995

Das Projekt "Mitarbeit an der Umweltprobenbank des Bundes im Jahre 1995" wird vom Umweltbundesamt gefördert und von Institut für Veterinär-Pharmakologie und Toxikologie durchgeführt. Im Probenahmezeitraum von September 1994 bis Dezember 1995 wurden 10 Rehleberproben aus dem Probenahmegebiet Duebener Heide gezogen und untersucht. Die Proben stammten von 2 Rehboecken und 8 Rehkitzen. Zu allen Proben liegt eine vollstaendige Dokumentation zur Probenahme und zur Charakterisierung der Proben vor. Es erfolgte eine Untersuchung auf die Elemente Na, K, Ca, Mg, Cu, Zn, Ni, Cd, Pb und Hg. Die Proben stammten von gesunden Tieren ohne Ekto- und Endoparasitenbefall. Der Bauchraum war bei keinem Tier verletzt. Parallel zu den Leberproben wurden im Rahmen der Qualitaetssicherung 5 Referenzmaterialien der Umweltprobenbank und 2 zertifizierte Referenzmaterialien (CRM 185 und CRM 278) untersucht. Fuer die untersuchten Rehlebern wurden die Mediane (mg je kg FS) ermittelt. Bei den Leberproben der Rehboecke deuten sich geringfuegig hoehere Gehalte bei den Na-, Cd- und Hg-Werten gegenueber den Werten der Rehkitze an. Fuer Cd wurde diese Tendenz bereits bei frueheren eigenen Untersuchungen (aus den Jahren 1992 - 1994) beobachtet. Bei den Elementen Cu und Ca ist innerhalb des Probenahmezeitraumes fuer Rehkitze von September bis Januar ein Trend zu niedrigeren Werten im Dezember/Januar zu verzeichnen. Inwieweit sich dieser Trend bestaetigt und moeglicherweise auch bei anderen Elementen (z. B. Mg, Zn, Na u. a.) von Bedeutung ist, muss weiteren Untersuchungen vorbehalten werden. Moegliche Einflussfaktoren fuer diesen Trend koennen sein: a) Altersabhaengigkeit; b) Umstellung der Ernaehrung der Rehkitze von Muttermilch auf pflanzliche Kost; c) saisonbedingte Unterschiede (Herbst/Winter) im Ernaehrungsverhalten der Tiere. Bei einem Vergleich der vorliegenden Untersuchungen zu den Rehkitzen mit Ergebnissen gleichartiger Tiere aus den Jahren 1992 und 1993 aus der Duebener Heide deutet sich bei den Elementen Cd, Pb und Hg eine Tendenz zu niedrigeren Werten an. Eine Bestaetigung des Trends erfordert jedoch die gleichzeitige Untersuchung aller bisher vorliegenden Proben der Umweltprobenbank. Die Analytik der obengenannten Elemente in den Referenzmaterialien (CRM 185 und 278) zeigt eine gute Uebereinstimmung mit den jeweiligen zertifizierten bzw. nicht zertifizierten Werten. Die ermittelten Gehalte liegen im Bereich von 89,9 Prozent bis 108,5 Prozent zum jeweiligen zertifizierten bzw. arithmetischen Mittelwert der Labormittelwerte bei den nicht zertifizierten Werten.

Messung des bodennahen Ozons

Das Projekt "Messung des bodennahen Ozons" wird vom Umweltbundesamt gefördert und von Universität Köln, Institut für Geophysik und Meteorologie durchgeführt. Die laufende Messung des bodennahen Ozons ist in einer Grossstadt von grosser Bedeutung fuer Umweltfragen. Die Konzentration des bodennahen Ozons ist ein empfindlicher Modikator fuer stagnierende Luft. Ozonwerte, die wesentlich ueber dem Durchschnitt liegen, weisen auf eine Smoglage hin.

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