The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Joseph K. Madathil - One of the best experts on this subject based on the ideXlab platform.
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Application of an ultrathin LiF/Al bilayer in Organic Surface-emitting diodes
Applied Physics Letters, 2001Co-Authors: L.s. Hung, Ching Wan Tang, M. G. Mason, Pranab K. Raychaudhuri, Joseph K. MadathilAbstract:Organic Surface-emitting diodes have been constructed with a multilayer stacked cathode consisting of (1) an ultrathin LiF/Al bilayer acting as an effective electron injector, (2) an optically low-loss and electrically conducting silver intermediate layer for sheet resistance reduction, and (3) a transparent and nonconducting capping layer for refractive index matching to optimize optical transmission. The entire cathode structure is prepared by conventional thermal evaporation without incurring radiation damage, and the resulting Organic Surface-emitting diodes exhibit superior electrical and optical characteristics.
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application of an ultrathin lif al bilayer in Organic Surface emitting diodes
Applied Physics Letters, 2001Co-Authors: L.s. Hung, Ching Wan Tang, M. G. Mason, Pranab K. Raychaudhuri, Joseph K. MadathilAbstract:Organic Surface-emitting diodes have been constructed with a multilayer stacked cathode consisting of (1) an ultrathin LiF/Al bilayer acting as an effective electron injector, (2) an optically low-loss and electrically conducting silver intermediate layer for sheet resistance reduction, and (3) a transparent and nonconducting capping layer for refractive index matching to optimize optical transmission. The entire cathode structure is prepared by conventional thermal evaporation without incurring radiation damage, and the resulting Organic Surface-emitting diodes exhibit superior electrical and optical characteristics.
Jörg Prietzel - One of the best experts on this subject based on the ideXlab platform.
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Microstructural and biochemical diversity of forest soil Organic Surface layers revealed by density fractionation
Geoderma, 2020Co-Authors: Jörg Prietzel, Sigrid Hiesch, Gertraud Harrington, Svenja MüllerAbstract:Abstract Particularly on sites with shallow, nutrient-poor soils, forest soil Organic Surface layers (O layers) are important for the storage of plant-available nutrients and water, and thus for forest vitality and productivity. O layers can contain up to 70 mass percent of inOrganic compounds (minerals) which may be spatially separated from or closely associated with soil Organic matter (SOM). O layer SOM may differ in biochemical properties and resistance against mineralization, depending on the extent of organo-mineral association. Moreover, type and intensity of SOM-mineral mixing in O layers conveys information about biological activity. Here, for the first time we present detailed density fractionation results to distinguish SOM constituents in O layers with different chemical properties and likely also different degrees of organo-mineral association. Additionally, we characterized spatial association patterns of the SOM fractions. We investigated samples of Of (Oe) and Oh (Oa) horizons of temperate forest soils with different parent materials (basalt, gneiss, andesite, Pleistocene gravel, dolomite). The samples were distinguished into six density fractions (ρ 1.6 g cm−3) by sequential treatment with deionized H2O (ρ = 1.0 g cm−3), 1-propanol (ρ = 0.8 g cm−3), and sodium polytungstate (SPT) solution of increasing density (ρ = 1.2, 1.4, 1.6 g cm−3). The procedure is characterized by a mass recovery of 93 ± 5% and an Organic carbon (OC) recovery of 90 ± 9%. In each fraction, we analyzed the concentrations of C, N, metal cations (Fe, Al, Ca, Mg), C speciation (13C NMR spectroscopy), as well as abundances of 13C and 15N. For selected fractions, we additionally determined the radiocarbon age and acquired microscopic images. From the Of to the Oh horizons, the contribution of heavy fractions (>1.4 g cm−3) to total soil mass and total SOC increased, indicating augmented organo–mineral association with progressive SOM decomposition state. Compared to bulk soil, heavier fractions >1.4 g cm−3 were characterized by smaller SOC concentrations, whereas concentrations of Al and Fe were increased for fractions >1.4 g cm−3 in the of and >1.6 g cm−3 in the Oh horizon. The SOM in the heavy fractions was enriched in N, carboxyl C, and alkyl C, but depleted in O/N-alkyl C and aryl C. Smaller mean particle sizes and C/N ratios as well as increased alkyl C / O/N-alkyl C ratios and 13C and 15N abundances indicate an advanced SOM decomposition state and enrichment of microbial-derived SOM in heavier fractions. However, according to its 14C signature, in contrast to high-density (ρ > 1.6 g cm−3) SOM in the mineral soil, forest floor SOM with high density is a rapidly cycling SOM pool with a turnover time
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Analysis of non-cellulosic polysaccharides helps to reveal the history of thick Organic Surface layers on calcareous Alpine soils
Plant and Soil, 2012Co-Authors: Jörg Prietzel, Nicolas Dechamps, Sandra SpielvogelAbstract:Background and aims We investigated the potential of non-cellulosic polysaccharides (NCP) as biomarkers to identify the plant types that dominate present and past litter input into Organic Surface covers on calcareous Alpine soils and to reveal historic vegetation changes.
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Microheterogeneity of element distribution and sulfur speciation in an Organic Surface horizon of a forested Histosol as revealed by synchrotron-based X-ray spectromicroscopy
Organic Geochemistry, 2011Co-Authors: Jörg Prietzel, Jürgen Thieme, David L. Paterson, Ingrid Kögel-knabner, Ian McnultyAbstract:Abstract In recent years, the relevance of physico-chemical heterogeneity patterns in soils at the micron and submicron scale for the regulation of biogeochemical processes has become increasingly evident. For an Organic Surface soil horizon from a forested Histosol in Germany, microspatial patterns of element distribution (sulfur, phosphorus, aluminium, silicon) and S speciation were investigated by synchrotron-based X-ray spectromicroscopy. Microspatial patterns of S, P, Al and Si contents in the Organic topsoil were assessed for a sample region of 50 μm × 30 μm by spatially resolving μ-XRF. Sulfur speciation at four microsites was investigated by focused X-ray absorption near edge structure (μ-XANES) spectroscopy at the S K -edge. The results show a heterogeneous distribution of the investigated elements on the (sub)micron scale, allowing the identification of diatoms, aluminosilicate mineral particles and sulfide minerals in the Organic soil matrix. Evaluation of the S K -edge μ-XANES spectra acquired at four different microsites by linear combination fitting revealed a substantial microspatial heterogeneity of S speciation, characterized by the presence of distinct enrichment zones of inOrganic sulfide and zones with dominant Organic disulfide S within a few micrometers distance, and coexistence of different S species (e.g. reduced inOrganic and Organic S compounds) at a spatial scale below the resolution of the instrument (60 nm × 60 nm; X-ray penetration depth: 30 μm).
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Microheterogeneity of element distribution and sulfur speciation in an Organic Surface horizon of a forested Histosol as revealed by synchrotron-based X-ray spectromicroscopy
Organic Geochemistry, 2011Co-Authors: Jörg Prietzel, Jürgen Thieme, David L. Paterson, Ingrid Kögel-knabner, Ian McnultyAbstract:Abstract In recent years, the relevance of physico-chemical heterogeneity patterns in soils at the micron and submicron scale for the regulation of biogeochemical processes has become increasingly evident. For an Organic Surface soil horizon from a forested Histosol in Germany, microspatial patterns of element distribution (sulfur, phosphorus, aluminium, silicon) and S speciation were investigated by synchrotron-based X-ray spectromicroscopy. Microspatial patterns of S, P, Al and Si contents in the Organic topsoil were assessed for a sample region of 50 μm × 30 μm by spatially resolving μ-XRF. Sulfur speciation at four microsites was investigated by focused X-ray absorption near edge structure (μ-XANES) spectroscopy at the S K -edge. The results show a heterogeneous distribution of the investigated elements on the (sub)micron scale, allowing the identification of diatoms, aluminosilicate mineral particles and sulfide minerals in the Organic soil matrix. Evaluation of the S K -edge μ-XANES spectra acquired at four different microsites by linear combination fitting revealed a substantial microspatial heterogeneity of S speciation, characterized by the presence of distinct enrichment zones of inOrganic sulfide and zones with dominant Organic disulfide S within a few micrometers distance, and coexistence of different S species (e.g. reduced inOrganic and Organic S compounds) at a spatial scale below the resolution of the instrument (60 nm × 60 nm; X-ray penetration depth: 30 μm).
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Phosphorus speciation of forest‐soil Organic Surface layers using P K‐edge XANES spectroscopy
Journal of Plant Nutrition and Soil Science, 2010Co-Authors: Jörg Prietzel, Jürgen Thieme, David L. PatersonAbstract:The phosphorus (P) speciation of Organic Surface layers from two adjacent German forest soils with different degree of water-logging (Stagnosol, Rheic Histosol) was analyzed by P K-edge XANES and subsequent Linear Combination Fitting. In both soils, {approx} 70% of the P was inOrganic phosphate and {approx} 30% Organic phosphate; reduced P forms such as phosphonate were absent. The increased degree of water-logging in the Histosol compared to the Stagnosol did not affect P speciation.
L.s. Hung - One of the best experts on this subject based on the ideXlab platform.
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Application of an ultrathin LiF/Al bilayer in Organic Surface-emitting diodes
Applied Physics Letters, 2001Co-Authors: L.s. Hung, Ching Wan Tang, M. G. Mason, Pranab K. Raychaudhuri, Joseph K. MadathilAbstract:Organic Surface-emitting diodes have been constructed with a multilayer stacked cathode consisting of (1) an ultrathin LiF/Al bilayer acting as an effective electron injector, (2) an optically low-loss and electrically conducting silver intermediate layer for sheet resistance reduction, and (3) a transparent and nonconducting capping layer for refractive index matching to optimize optical transmission. The entire cathode structure is prepared by conventional thermal evaporation without incurring radiation damage, and the resulting Organic Surface-emitting diodes exhibit superior electrical and optical characteristics.
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application of an ultrathin lif al bilayer in Organic Surface emitting diodes
Applied Physics Letters, 2001Co-Authors: L.s. Hung, Ching Wan Tang, M. G. Mason, Pranab K. Raychaudhuri, Joseph K. MadathilAbstract:Organic Surface-emitting diodes have been constructed with a multilayer stacked cathode consisting of (1) an ultrathin LiF/Al bilayer acting as an effective electron injector, (2) an optically low-loss and electrically conducting silver intermediate layer for sheet resistance reduction, and (3) a transparent and nonconducting capping layer for refractive index matching to optimize optical transmission. The entire cathode structure is prepared by conventional thermal evaporation without incurring radiation damage, and the resulting Organic Surface-emitting diodes exhibit superior electrical and optical characteristics.
Ian Mcnulty - One of the best experts on this subject based on the ideXlab platform.
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Microheterogeneity of element distribution and sulfur speciation in an Organic Surface horizon of a forested Histosol as revealed by synchrotron-based X-ray spectromicroscopy
Organic Geochemistry, 2011Co-Authors: Jörg Prietzel, Jürgen Thieme, David L. Paterson, Ingrid Kögel-knabner, Ian McnultyAbstract:Abstract In recent years, the relevance of physico-chemical heterogeneity patterns in soils at the micron and submicron scale for the regulation of biogeochemical processes has become increasingly evident. For an Organic Surface soil horizon from a forested Histosol in Germany, microspatial patterns of element distribution (sulfur, phosphorus, aluminium, silicon) and S speciation were investigated by synchrotron-based X-ray spectromicroscopy. Microspatial patterns of S, P, Al and Si contents in the Organic topsoil were assessed for a sample region of 50 μm × 30 μm by spatially resolving μ-XRF. Sulfur speciation at four microsites was investigated by focused X-ray absorption near edge structure (μ-XANES) spectroscopy at the S K -edge. The results show a heterogeneous distribution of the investigated elements on the (sub)micron scale, allowing the identification of diatoms, aluminosilicate mineral particles and sulfide minerals in the Organic soil matrix. Evaluation of the S K -edge μ-XANES spectra acquired at four different microsites by linear combination fitting revealed a substantial microspatial heterogeneity of S speciation, characterized by the presence of distinct enrichment zones of inOrganic sulfide and zones with dominant Organic disulfide S within a few micrometers distance, and coexistence of different S species (e.g. reduced inOrganic and Organic S compounds) at a spatial scale below the resolution of the instrument (60 nm × 60 nm; X-ray penetration depth: 30 μm).
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Microheterogeneity of element distribution and sulfur speciation in an Organic Surface horizon of a forested Histosol as revealed by synchrotron-based X-ray spectromicroscopy
Organic Geochemistry, 2011Co-Authors: Jörg Prietzel, Jürgen Thieme, David L. Paterson, Ingrid Kögel-knabner, Ian McnultyAbstract:Abstract In recent years, the relevance of physico-chemical heterogeneity patterns in soils at the micron and submicron scale for the regulation of biogeochemical processes has become increasingly evident. For an Organic Surface soil horizon from a forested Histosol in Germany, microspatial patterns of element distribution (sulfur, phosphorus, aluminium, silicon) and S speciation were investigated by synchrotron-based X-ray spectromicroscopy. Microspatial patterns of S, P, Al and Si contents in the Organic topsoil were assessed for a sample region of 50 μm × 30 μm by spatially resolving μ-XRF. Sulfur speciation at four microsites was investigated by focused X-ray absorption near edge structure (μ-XANES) spectroscopy at the S K -edge. The results show a heterogeneous distribution of the investigated elements on the (sub)micron scale, allowing the identification of diatoms, aluminosilicate mineral particles and sulfide minerals in the Organic soil matrix. Evaluation of the S K -edge μ-XANES spectra acquired at four different microsites by linear combination fitting revealed a substantial microspatial heterogeneity of S speciation, characterized by the presence of distinct enrichment zones of inOrganic sulfide and zones with dominant Organic disulfide S within a few micrometers distance, and coexistence of different S species (e.g. reduced inOrganic and Organic S compounds) at a spatial scale below the resolution of the instrument (60 nm × 60 nm; X-ray penetration depth: 30 μm).
M. G. Mason - One of the best experts on this subject based on the ideXlab platform.
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Application of an ultrathin LiF/Al bilayer in Organic Surface-emitting diodes
Applied Physics Letters, 2001Co-Authors: L.s. Hung, Ching Wan Tang, M. G. Mason, Pranab K. Raychaudhuri, Joseph K. MadathilAbstract:Organic Surface-emitting diodes have been constructed with a multilayer stacked cathode consisting of (1) an ultrathin LiF/Al bilayer acting as an effective electron injector, (2) an optically low-loss and electrically conducting silver intermediate layer for sheet resistance reduction, and (3) a transparent and nonconducting capping layer for refractive index matching to optimize optical transmission. The entire cathode structure is prepared by conventional thermal evaporation without incurring radiation damage, and the resulting Organic Surface-emitting diodes exhibit superior electrical and optical characteristics.
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application of an ultrathin lif al bilayer in Organic Surface emitting diodes
Applied Physics Letters, 2001Co-Authors: L.s. Hung, Ching Wan Tang, M. G. Mason, Pranab K. Raychaudhuri, Joseph K. MadathilAbstract:Organic Surface-emitting diodes have been constructed with a multilayer stacked cathode consisting of (1) an ultrathin LiF/Al bilayer acting as an effective electron injector, (2) an optically low-loss and electrically conducting silver intermediate layer for sheet resistance reduction, and (3) a transparent and nonconducting capping layer for refractive index matching to optimize optical transmission. The entire cathode structure is prepared by conventional thermal evaporation without incurring radiation damage, and the resulting Organic Surface-emitting diodes exhibit superior electrical and optical characteristics.