API src

Found 1521 results.

Related terms

LegacyVegetation: Northern Hemisphere reconstruction of past plant cover and total tree cover from pollen archives of the last 14 ka

This data set presents the reconstructed vegetation cover for 2773 sites based on harmonized pollen data from the data set LegacyPollen 2.0 (https://doi.pangaea.de/10.1594/PANGAEA.965907). 1040 sites are located in North America, 1287 in Europe, and 446 in Asia. Sugita's REVEALS model (2007) was applied to all pollen records using REVEALSinR from the DISQOVER package (Theuerkauf et al. 2016). Pollen counts were translated into vegetation cover by accounting for taxon-specific pollen productivity and fall speed. Additionally, relevant source areas of pollen were calculated using the aforementioned taxon-specific parameters and a Gaussian plume model for deposition and dispersal. Values for relative pollen productivity and fall speed from the synthesis from Wiezcorek and Herzschuh (2010) were updated with recent studies used to reconstruct vegetation cover. The average values from all Northern Hemisphere values were used where taxon-specific continental values were unavailable. As REVEALS was conceived to reconstruct vegetation from large lakes, only records originating from large lakes (>= 50h) are marked as "valid as site" in the dataset. Reconstructions from other records can be used when spatially averaging several together. An example script to do so is provided on Zenodo (https://doi.org/10.5281/zenodo.12800290). Reconstructed tree cover was validated using modern Landsat remote sensing forest cover. Reconstructed tree cover has much lower errors than the original arboreal pollen percentages. Reconstructions of individual taxa are more uncertain. We present tables with reconstructed vegetation cover for all continents with original parameters. As further details, we list a table with the taxon-specific parameters used, metadata for all records, and a list of parameters adjusted in the default version of REVEALSinR.

LegacyVegetation: Asian reconstruction of past plant cover and total tree cover from pollen archives of the last 14 ka

This data set presents the reconstructed vegetation cover for 446 Asian sites based on harmonized pollen data from the data set LegacyPollen 2.0. Sugita's REVEALS model (2007) was applied to all pollen records using REVEALSinR from the DISQOVER package (Theuerkauf et al. 2016). Pollen counts were translated into vegetation cover by accounting for taxon-specific pollen productivity and fall speed. Additionally, relevant source areas of pollen were calculated using the aforementioned taxon-specific parameters and a Gaussian plume model for deposition and dispersal. Values for relative pollen productivity and fall speed from the synthesis from Wiezcorek and Herzschuh (2010) were updated with recent studies used to reconstruct vegetation cover. The average values from all Northern Hemisphere values were used where taxon-specific continental values were unavailable. As REVEALS was conceived to reconstruct vegetation from large lakes, only records originating from large lakes (>= 50h) are marked as "valid as site" in the dataset. Reconstructions from other records can be used when spatially averaging several together. An example script to do so is provided on Zenodo (https://doi.org/10.5281/zenodo.12800290). Reconstructed tree cover was validated using modern Landsat remote sensing forest cover. Reconstructed tree cover has much lower errors than the original arboreal pollen percentages. Reconstructions of individual taxa are more uncertain. We present tables with reconstructed vegetation cover for all continents with original parameters. As further details, we list a table with the taxon-specific parameters used, metadata for all records, and a list of parameters adjusted in the default version of REVEALSinR.

Horizontal-to-Vertical Spectral Ratios (HVSR) of NW Italy seismic stations elaborated during the "FOCUS-HVNEA" NOA-ILGE project

This data set consists of Horizontal-to-Vertical Spectral Ratios (HVSR) resulting from the application of the software package HVNEA (HV Noise and Earthquake Automatic Analysis) with the aim of comparing them with those resulting from the application of another method, namely STATION (Seismic sTATion and sIte amplificatiON). The results, relative to more than 24,000 HVSR, derive from the processing of 700,000 seismograms recorded over different time periods by 8 stations of the networks IV (Italian Seismic Network), GU (Regional Seismic Network of North Western Italy) and GV (Mobile RSNI). To compare the results of the two methods as accurately as possible, the waveforms were subjected to the same preprocessing already used to elaborate the results stored in the STATION database. To this end, the methodological workflow applied with HVNEA for station IV.MURB involved the selection of segments from continuous recordings for each event reported in the INGV catalogue located within a radius of 120 kilometres from the station. Starting from the automatically picked S-wave onsets, 12-second windows were then extracted and used for the analysis of earthquake recordings. Regarding the noise analysis, it should be noted that STATION again considers 12-second windows selected before the P-wave onset, while HVNEA requires the use of a signal window of at least 60 seconds. A window of 3,600 seconds was used for the analysis. The comparison of the HVSR was performed in the frequency band 0.1–15 Hz. All analysed curves, for both earthquake and noise recordings, show generally similar shapes and identify significant peaks in correspondence of the same frequency ranges, although the amplitudes obtained with STATION are systematically higher than those obtained with HVNEA. To obtain a quantitative comparison, various statistical metrics commonly used to measure the discrepancy between data sets were applied, namely the Mean Squared Error, the Mean Absolute Error and the Pearson Correlation Coefficient. This publication results from work conducted under the transnational access/national open access action at the Site effects Laboratory – INGV L’Aquila supported by WP3 ILGE–MEET project, PNRR–EU Next Generation Europe program, MUR grant number D53C22001400005.

Hocheffiziente und robuste Leistungselektronik - ERLE

Biogeochemische Prozesse und Ozean/Atmosphäre- Austauschprozesse in marinen Oberflächenfilmen (BASS): Chemische und Photochemische Umsetzung Organischer Stoffe

Die Grenzfläche zwischen Ozean und Atmosphäre ist durch einen allgegenwärtigen, < 1 mm dicken marinen Oberflächenfilm, den sogenannten sea-surface microlayer (SML), charakterisiert. Der SML ist nicht nur direkter UV-Strahlung und atmosphärischen Oxidantien ausgesetzt, sondern zeichnet sich im Vergleich zum unterliegenden Wasser auch durch höhere Konzentrationen an organischen Stoffen aus. Bisher ist unklar, welche Bedeutung die dadurch bedingten SML-spezifischen abiotischen Prozesse für die Umsetzung und die Emission organischer Stoffe insgesamt haben und wie man diese Prozesse parametrisieren kann. In diesem Projekt, das eng mit anderen Projekten der interdisziplinären Forschungsgruppe â€ÌBiogeochemische Prozesse und Ozean/Atmosphäre- Austauschprozesse in marinen Oberflächenfilmen (BASS)â€Ì verbunden ist, sollen daher molekulare Details SML-spezifischer Reaktionen (Photochemie, heterogene Oxidation, Radikalchemie) genauer untersucht werden. Ziel ist es, Reaktionsprodukte und -geschwindigkeiten quantitativ zu erfassen und Unterschiede zwischen Reaktionen im SML und in der freien Wassersäule herauszuarbeiten. Basierend auf der Expertise der drei beteiligten Arbeitsgruppen im Bereich Photochemie, Reaktionskinetik, Laserspektroskopie, Analytik und theoretischer Modellierung, soll ein molekulares Verständnis ausgewählter Reaktionen und des Einflusses der komplexen SML-Reaktionsumgebung erreicht werden. Dazu sollen experimentelle Verfahren wie Schwingungs-Summenfrequenzerzeugung, hochempfindliche Chromatographie-Massenspektrometrie und gepulste Laserphotolyse-Langwegabsorption mit Methoden der Quantenchemie und Molekulardynamik kombiniert werden. Arbeitsschwerpunkte bilden die Oxidationskinetik von Halogen- bzw. Hydroxyl-Radikalreaktionen in der flüssigen Phase, die Ozonolyse von Fettsäure-Monoschichten und die durch Photosensibilisatoren verstärkte Bildung von reaktiven Radikalen bzw. Zersetzung von organischen Schichten. Neben wohldefinierten Labor-Modellsystemen werden auch natürliche Proben analysiert werden. Dabei stellt sich z.B. die Frage nach den Einflussfaktoren der während einer Algenblüte zunehmenden Bildung von oberflächenaktiven Stoffen im SML und der Bedeutung der durch die Sonne bedingten Photolyse auf die abiotische Umsetzung organischer Stoffe. Flankierend werden im Projekt auch die eingesetzten Untersuchungsmethoden weiterentwickelt; das beinhaltet sowohl die Ausarbeitung von Messprotokollen zur Quantifizierung bestimmter organischen Substanzklassen (z.B. Carbonyle und Kohlenhydrate) im SML, die Synthese und Charakterisierung von neuartigen oberflächenaktiven Photosensibilisatoren (z.B. Benzoyl-Benzoesäure-funktionalisierte Lipide) sowie die Entwicklung und Erprobung mehrstufiger Modellierungsverfahren zur theoretischen Beschreibung von Struktur-Reaktivitätsbeziehungen der Fettsäure-Ozonolyse (z.B. Beschreibung des Einflusses sterischer und elektronischer Effekte der organischen Matrix).

replacePlastic

Kurzbeschreibung Mit der Smartphone App replacePlastic können Verbraucher die Barcodes von Produkten scannen, um den Herstellern über die App mitzuteilen, dass sie sich das entsprechende Produkt in einer Verpackung ohne Plastik/mit weniger Plastik wünschen. Küste gegen Plastik e.V. möchte der Behauptung vieler Hersteller, dass durch Plastikverpackungen in erster Linie den Kundeninteressen entsprochen würde, die Stimmen der Kunden sichtbar entgegenstellen. Mit der App sollen Kunden die Möglichkeit erhalten, den Herstellern von Produkten ein Feedback zu ihren Plastikverpackungen zu senden. Die Kunden scannen dazu den Barcode eines Produktes ein und vermitteln dem Hersteller anschließend, dass sie sich das jeweilige Produkt in einer umweltfreundlicheren Verpackung wünschen. Die Meldungen werden zunächst in einer Datenbank gesammelt, gebündelt an den Hersteller übermittelt sowie auf einer Website visualisiert. Auf diese Weise erhält der Hersteller einerseits wertvolle Marktforschungsdaten, andererseits kann sich Öffentlichkeit darüber informieren, welche Produktverpackungen von anderen Verbrauchern kritisch gesehen werden. Dies regt die öffentliche Diskussion um Verpackungen sowie geeignete Alternativen an und gibt den Verbrauchern ein Mittel an die Hand, ihrem Wunsch nach besseren Verpackungen zum Ausdruck zu bringen. Ziel ist weiterhin der Aufbau einer konstruktiven Kommunikation mit den Herstellern von Produkten und weiteren Stakeholdern zur Unterstützung von innovativen Lösungen. Auf der Website sollen die Reaktionen du Wünsche der Verbraucher sichtbar gemacht werden, sowie über positive Veränderungen und Reaktionen der Hersteller berichtet werden. Ergebnisse Siehe Website

Reservoir-modelling and parametrization of a potential reservoir structure (Pilot area B) in the German North Sea

As part of the CDRmare joint project GEOSTOR (https://geostor.cdrmare.de/), the BGR created detailed static geological 3D models for two potential CO2 storage structures in the Middle Buntsandstein in the Exclusive Economic Zone (EEZ) of the German North Sea and supplemented them with petrophysical parameters (e.g. porosities, permeabilities). The 3D geological model (Pilot area B; ~560 km2) is located in the north-western part of the German North Sea sector, the so-called “Entenschnabel”, an approximately 150 kilometer long and 30 kilometer wide area between the offshore sectors of the Netherlands, Denmark and Great Britain (pilot region B). The model in the Ducks Beak is based on several high-resolution 3D seismic data and geophysical/geological information from four exploration wells. It includes 20 generalized faults and the following 16 horizon surfaces: 1) Sea Floor, 2) Mid Miocene Unconformity, 3) Base Tertiary, 4) Base Upper Cretaceous, 5) Base Lower Cretaceous, 6) Base Upper Jurassic, 7) Base Lower Jurassic, 8) Base Muschelkalk, 9) Base Röt, 10) Base Solling Formation, 11) Base Detfurth Formation, 12) Base Volpriehausen Wechselfolge, 13) Base Volpriehausen Formation, 14) Base Triassic, 15) Base Zechstein, 16) Top Basement. The reservoir formed by sandstones of the Middle Buntsandstein is located within the Mads Graben, which is bounded to the west by the extensive Mads Fault (normal fault). Marine mudstones of the Upper Jurassic and Lower Cretaceous serve as the main seal formations. Petrophysical analyses of all considered well data were conducted and reservoir properties (including porosity and permeability) were calculated to determine the static reservoir capacity for these potential CO2 storage structures. The model parameterized and can be used for further dynamic simulations of storage capacity, geo-risk, and infrastructure analyses, in order to develop a comprehensive feasibility study for potential CO2 storage within the project framework. The 3D models were created by the BGR between 2021 and 2024. SKUA-GOCAD was used as the modeling software. We would like to thank AspenTech for providing licenses for their SSE software package as part of the Academic Program (https://www.aspentech.com/en/academic-program).

Reservoir-modelling and parametrization of a potential reservoir structure (Pilot area A) in the German North Sea

As part of the CDRmare joint project GEOSTOR (https://geostor.cdrmare.de/), the BGR created detailed static geological 3D models for two potential CO2 storage structures in the Middle Buntsandstein in the Exclusive Economic Zone (EEZ) of the German North Sea and supplemented them with petrophysical parameters (e.g. porosities, permeabilities). The 3D geological model (Pilot area A; ~1300 km2) is located on the West Schleswig Block in the area of the Henni salt pillow (pilot region A). It is based on 2D seismic data from various surveys and geophysical/geological information from four exploration wells. The model comprises 14 generalized faults and the following 14 horizon surfaces: 1) Sea Floor, 2) Mid Miocene Unconformity, 3) Base Rupelian, 4) Base Tertiary, 5) Base Upper Cretaceous, 6) Base Lower Cretaceous, 7) Base Muschelkalk, 8) Base Röt (Pelite), 9) Base Röt (Salinar), 10) Base Solling Formation, 11) Base Detfurth Formation, 12) Base Volpriehausen Formation, 13) Base Triassic, 14) Base Zechstein. The selected potential reservoir structure in the Middle Buntsandstein is formed by an anticline created by the uplift of the underlying Henni salt pillow. The primary reservoir unit is the 40-50 m thick Lower Volpriehausen Sandstone, the main sealing units are the Röt and the Lower Cretaceous. Petrophysical analyses of all considered well data were conducted and reservoir properties (including porosity and permeability) were calculated to determine the static reservoir capacity for these potential CO2 storage structures. Both models were parameterized and can be used for further dynamic simulations of storage capacity, geo-risk, and infrastructure analyses, in order to develop a comprehensive feasibility study for potential CO2 storage within the project framework. The 3D models were created by the BGR between 2021 and 2024. SKUA-GOCAD was used as the modeling software. We would like to thank AspenTech for providing licenses for their SSE software package as part of the Academic Program (https://www.aspentech.com/en/academic-program).

Konsolidierung des HTR Code Package (HCP), Konsolidierung des HTR Code Package (HCP), Teilprojekt A

Multibeam bathymetry raw data (Atlas Hydrosweep DS 3 echo sounder entire dataset) of RV POLARSTERN during cruise PS151

Multibeam data were collected with RV Polarstern along the route of cruise PS151 and data acquisition was almost continuously monitored during the survey. Multibeam sonar system was Teledyne/Atlas Hydrosweep DS3. SVPs were retrieved from CTD data and synthetic profiles from World Ocean Atlas 23. SVPs were processed with HydrOffice SoundSpeedManager (https://www.hydroffice.org/soundspeed/main) and extended with World Ocean Atlas 23 (https://www.ncei.noaa.gov/archive/accession/NCEI-WOA23). SVP data were applied during acquisition. Multibeam data are unprocessed and may contain outliers and blunders and should not be used for grid calculations and charting projects without further editing. The raw multibeam sonar data in Teledyne Reson multibeam processing format (.s7k) were recorded with Teledyne PDS software. Raw data files can be processed using software packages like CARIS HIPS/SIPS. For updated vessel configuration files check further details.

1 2 3 4 5 … 151 152 153