0000000000636338

AUTHOR

D. Walter

showing 11 related works from this author

TID and SEE Tests of an Advanced 8 Gbit NAND-Flash Memory

2008

We report on the dose and operational mode dependence of error percentage, stand-by current, erase and write time of 8 Gbit / 4 Gbit NAND-flash memories as well as on their static, dynamic and SEFI cross sections.

Non-volatile memoryHardware_MEMORYSTRUCTURESComputer scienceNand flash memorybusiness.industryGigabitHardware_ARITHMETICANDLOGICSTRUCTURESbusinessComputer hardwareFlash memoryHardware_LOGICDESIGN2008 IEEE Radiation Effects Data Workshop
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MBU characterization of NAND-Flash memories under heavy-ion irradiation

2011

The angular dependence of the MBU-Cross-Section of two 8-Gbit-SLC-NAND-Flash and the orientation of the MBU-pattern has been measured.

Flash (photography)Materials sciencebusiness.industryElectrical engineeringNAND gateOptoelectronicsAngular dependencebusinessHeavy ion irradiationCharacterization (materials science)2011 12th European Conference on Radiation and Its Effects on Components and Systems
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Heavy ion SEE studies on 4-Gbit NAND-Flash memories

2007

Heavy ion SEE studies on three 4-Gbit NAND-flash memory types were performed at the RADEF facility at the University of Jyvaskyla, Finland with particular emphasis on SEFI differentiation. An error classification for complex memory devices is introduced, and respective cross sections are reported.

Flash (photography)Hardware_MEMORYSTRUCTURESComputer scienceGigabitEmphasis (telecommunications)Electronic engineeringNAND gateHeavy ionTransient analysisFlash memory2007 9th European Conference on Radiation and Its Effects on Components and Systems
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African volcanic emissions influencing atmospheric aerosols over the Amazon rain forest

2018

Long-range transport (LRT) plays an important role in the Amazon rain forest by bringing in different primary and secondary aerosol particles from distant sources. The atmospheric oxidation of dimethyl sulfide (DMS), emitted from marine plankton, is considered an important sulfate source over the Amazon rain forest, with a lesser contribution from terrestrial soil and vegetation sulfur emissions. Volcanic sulfur emissions from Africa could be a source of particulate sulfate to the Amazonian atmosphere upon transatlantic transport but no observations have been published. By using satellite observations, together with ground‑based and airborne aerosol particle observations, this paper provide…

Atmospheric Science010504 meteorology & atmospheric sciencesAmazonian[SDE.MCG]Environmental Sciences/Global Changes010502 geochemistry & geophysicsAtmospheric sciences01 natural sciencescomplex mixtureslcsh:ChemistryAtmospherechemistry.chemical_compoundparasitic diseasesCloud condensation nucleiSulfate0105 earth and related environmental sciences[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph][SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmospheregeographygeography.geographical_feature_category15. Life on landParticulateslcsh:QC1-999Trace gasAerosollcsh:QD1-999Volcanochemistry13. Climate actionEnvironmental sciencegeographic locationslcsh:Physics
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Black and brown carbon over central Amazonia: long-term aerosol measurements at the ATTO site

2018

The Amazon rainforest is a sensitive ecosystem experiencing the combined pressures of progressing deforestation and climate change. Its atmospheric conditions oscillate between biogenic and biomass burning (BB) dominated states. The Amazon further represents one of the few remaining continental places where the atmosphere approaches pristine conditions during occasional wet season episodes. The Amazon Tall Tower Observatory (ATTO) has been established in central Amazonia to investigate the complex interactions between the rainforest ecosystem and the atmosphere. Physical and chemical aerosol properties have been analyzed continuously since 2012. This paper provides an in-depth analysis of t…

Atmospheric Science010504 meteorology & atmospheric sciencesSingle-scattering albedoAmazon rainforest010501 environmental sciencesCombustionAtmospheric sciences01 natural scienceslcsh:QC1-999Aerosollcsh:ChemistryAtmospherelcsh:QD1-999Dry seasonForest ecologyEnvironmental scienceAbsorption (electromagnetic radiation)lcsh:Physics0105 earth and related environmental sciencesAtmospheric Chemistry and Physics
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Land cover and its transformation in the backward trajectory footprint region of the Amazon Tall Tower Observatory

2019

Abstract. The Amazon rain forest experiences the combined pressures from human-made deforestation and progressing climate change, causing severe and potentially disruptive perturbations of the ecosystem's integrity and stability. To intensify research on critical aspects of Amazonian biosphere–atmosphere exchange, the Amazon Tall Tower Observatory (ATTO) has been established in the central Amazon Basin. Here we present a multi-year analysis of backward trajectories to derive an effective footprint region of the observatory, which spans large parts of the particularly vulnerable eastern basin. Further, we characterize geospatial properties of the footprint regions, such as climatic condition…

0106 biological sciencesAtmospheric Science010504 meteorology & atmospheric sciences[SDE.MCG]Environmental Sciences/Global ChangesAmazonianClimate changeContext (language use)Land cover010603 evolutionary biology01 natural scienceslcsh:ChemistryDeforestationEcosystem0105 earth and related environmental sciences[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]Fire regimeAmazon rainforest15. Life on landlcsh:QC1-999POLUIÇÃO ATMOSFÉRICAlcsh:QD1-99913. Climate actionClimatologyEnvironmental sciencelcsh:Physics
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Bioaerosols in the Amazon rain forest: temporal variations and vertical profiles of Eukarya, Bacteria, and Archaea

2021

The Amazon rain forest plays a major role in global hydrological cycling, and biogenic aerosols are likely to influence the formation of clouds and precipitation. Information about the sources and altitude profiles of primary biological aerosol particles, however, is sparse. We used fluorescence in situ hybridization (FISH), a molecular biological staining technique largely unexplored in aerosol research, to investigate the sources and spatiotemporal distribution of Amazonian bioaerosols on the domain level. We found wet season bioaerosol number concentrations in the range of 1–5 × 105 m−3 accounting for > 70 % of the coarse mode aerosol. Eukaryotic and bacterial particles predominated, …

QE1-996.5EcologyAmazonianIndoor bioaerosolGeologyUnderstoryAtmospheric sciencesAerosolAltitudeBioprecipitationLifeQH501-531Environmental sciencePrecipitationEcology Evolution Behavior and SystematicsQH540-549.5Earth-Surface ProcessesBioaerosol
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Influx of African biomass burning aerosol during the Amazonian dry season through layered transatlantic transport of black carbon-rich smoke

2020

Black carbon (BC) aerosols influence the Earth's atmosphere and climate, but their microphysical properties, spatiotemporal distribution, and long-range transport are not well constrained. This study presents airborne observations of the transatlantic transport of BC-rich African biomass burning (BB) smoke into the Amazon Basin using a Single Particle Soot Photometer (SP2) as well as several complementary techniques. We base our results on observations of aerosols and trace gases off the Brazilian coast onboard the HALO (High Altitude and LOng range) research aircraft during the ACRIDICON-CHUVA campaign in September 2014. During flight AC19 over land and ocean at the northeastern coastline …

Atmospheric Science010504 meteorology & atmospheric sciences[SDE.MCG]Environmental Sciences/Global ChangesPopulation010502 geochemistry & geophysicsAtmospheric sciences01 natural sciencesAtmospherelcsh:ChemistryAltitudeConvective mixingddc:550Cloud condensation nucleiMass concentration (chemistry)educationbiomass burning aerosol transport airborne measurement Amazon basin0105 earth and related environmental sciences[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]education.field_of_studyAmazon rainforestAtmosphärische Spurenstoffe15. Life on landOberpfaffenhofenBACIA HIDROGRÁFICAlcsh:QC1-999Aerosollcsh:QD1-99913. Climate actionEnvironmental sciencelcsh:Physics
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Preliminary results of carbon degassing in the tectonically active areas of Balkan Peninsula

2020

The deeply derived CO2 from tectonically active areas is contributing in a significant proportion, still unquantified in detail, to CO2 Earth degassing. Several studies highlighted how in these tectonically active areas most of the CO2 is dissolved in the groundwaters circulating in the large regional aquifers hosted by the permeable formations of the active orogens. Quantifying the amount of deep CO2 dissolved into groundwater can represent a powerful tool for regional investigations, because springs are representative of their catchment area that can extend from tens to hundreds of square kilometers. In the framework of a Deep Carbon Observatory supported project, we investigated for the …

Carbon dioxide Earth degassing geochemistry Balkan Peninsula
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Thermomineral waters of Greece: geochemical characterization

2020

75 °C). In terms of pH most results vary from 5.5 to 823 °C) ii) warm (23 40 °C) iii) thermal (40 75 °C) and iv) hyperthermal (&gtfew springs show either very low pH (&lt10) proposing serpentinization processes. Regarding TDS concentrations collected waters can be subdivided into low salinity (up to 1.5 g/L) brackish (up to 20 g/L) and saline (up to 43 g/L). The medium high salinities can be justified by mixing with sea water and/or strong waterrock interaction processes. Isotope composition of O and H ranges from 12.7 to +2.7 ‰ SMOW and from 91 to +12 ‰ SMOW respectively and is generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Only few water samples show a positive shift for δ18O possibly related to high temperature waterrock interaction processes. Carbon dioxide (18 997000 μmol/mol) or N2 (1100 989000 μmol/mol) or CH4 (&ltMany geothermal areas of Greece are located in regions affected by Miocene or Quaternary volcanism and in continental basins characterised by elevated heat flow. Moreover the majority of them is found along the coast as well as in islands of the Aegean Sea and thus thermal water is often brackish to saline due to marine intrusion into costal aquifer. In the present study almost 300 thermal and cold mineral water samples were collected along the Hellenic territory with their physicochemical parameters (temperature pH electrical conductivity and Eh) and the amount of bicarbonates (titration with 0.1N HCl) being determined in situ. Additionally gases found either in free or dissolved phase were sampled. Both water and gas samples were analysed at the INGVPa laboratories for major ions (Ion Chromatography) silica (Inductively Coupled Plasma Optical Emission Spectrometry) chemical composition of free and dissolved gases (Gas Chromatography) water isotopes (O and H) and carbon and helium isotopes of free and dissolved gases (Mass Spectrometry). The temperature of the investigated waters ranges from 6.5 to 98°C pH from 1.96 to 11.98 whilst Total Dissolved Solids (TDS) from 0.06 to 43 g/L. Based on the temperature parameter waters can be divided into four groups: i) cold (&lt0.5 913000 μmol/mol) are the prevailing gas species found in the studied sites. The δ13CCO2 values ranged from 20.1 to +8.5 ‰ whilst the isotope ratio of He from 0.21 to 6.71 R/RA.4) suggesting interaction with H2Srich gases or very high pH values (&gtSettore GEO/08 - Geochimica E Vulcanologia
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Geochemical characterization of trace elements in thermomineral waters of Greece

2020

Trace elements have a fundamental role in natural and anthropogenic systems. In waters, they present a great variability of concentrations that mostly depends on the degree of gaswaterrock interactions and geochemical conditions such as pH, temperature, redox and/or exchange reactions, etc. Even though, they are present in very low contents in hostrocks, elevated concentrations in ground or surface waters may have a hazardous impact on human and animal health and thus, it is important to both quantify and try to understand their behaviour in natural systems. Here we present the results of about 300 cold and thermal mineral waters collected along the entire Hellenic territory. Physicochemica…

water geochemistry trace elements GreeceSettore GEO/08 - Geochimica E Vulcanologia
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