ABSTRACT Perovskite-type mixed ionic-electronic conductor oxides are used as Solid Oxide Fuel Cel... more ABSTRACT Perovskite-type mixed ionic-electronic conductor oxides are used as Solid Oxide Fuel Cell cathodes (SOFC). A major limitation in cathode performance is the slow kinetics of oxygen exchange on the perovskite oxide surfaces, particularly at lower temperatures (T
In membrane bioreactors (MBR) for wastewater treatment, the separation of activated sludge and tr... more In membrane bioreactors (MBR) for wastewater treatment, the separation of activated sludge and treated water takes place by membrane filtration. Due to the small footprint and superior effluent quality, the number of membrane bioreactors used in wastewater treatment is rapidly increasing. A major challenge in this process is the fouling of the membranes which results in permeability decrease and the demand of chemical cleaning procedures. With the objective of a chemical-free process, the removal of the fouling layer by continuous physical abrasion was investigated. Therefore, particles (granules) were added to the activated sludge in order to realise a continuous abrasion of the fouling layer. During operation for more than 8 months, the membranes showed no decrease in permeability. Fluxes up to 40 L/(m(2) h) were achieved. An online turbidity measurement was installed for the effluent control and showed no change during this test period. For comparison, a reference (standard MBR process without granules) was operated which demonstrated permeability loss at lower fluxes and required chemical cleaning. Altogether with this process an operation at higher fluxes and no use of cleaning chemicals will increase the cost efficiency of the MBR-process.
ABSTRACT This paper introduces the special section on “New Modelling Approaches and Novel Experim... more ABSTRACT This paper introduces the special section on “New Modelling Approaches and Novel Experimental Technologies for Improved Understanding of Process Dynamics at Aquifer-Surface Water Interfaces”. It is contextualising the framework for the 27 research papers of the special section by firth identifying research gaps and imminent challenges for ecohydrological research at aquifer-surface water interfaces and then discussing the specific paper contributions on (i) New Developments in Temperature/Heat Tracing at GW-SW Interfaces, (ii) New methods to capture the temporal and spatial variability of groundwater – surface water exchange (iii) New Approaches in Modelling Aquifer-River Exchange Flow and (iv) New Concepts and Advanced Theory of Groundwater – Surface Water Exchange.
The future of nanoscale spin-based technologies hinges on a fundamental understanding and dynamic... more The future of nanoscale spin-based technologies hinges on a fundamental understanding and dynamic control of atomic-scale magnets. The role of the substrate conduction electrons on the dynamics of supported atomic magnets is still a question of interest lacking experimental insight. We characterized the temperature-dependent dynamical response of artificially constructed magnets, composed of a few exchange-coupled atomic spins adsorbed on a metallic substrate, to spin-polarized currents driven and read out by a magnetic scanning tunneling microscope tip. The dynamics, reflected by two-state spin noise, is quantified by a model that considers the interplay between quantum tunneling and sequential spin transitions driven by electron spin-flip processes and accounts for an observed spin-transfer torque effect.
The mammillary bodies (MB) are important relay nuclei within limbic and extralimbic connections. ... more The mammillary bodies (MB) are important relay nuclei within limbic and extralimbic connections. They are known to play important roles in memory formation and are affected in alcoholism and vitamin B1 deficiency. Their strategic position linking temporo-limbic to cortico-thalamic brain structures make the MB a candidate brain structure for alterations in schizophrenia. We studied 15 postmortem brains of schizophrenics and 15 matched control brains. Brain sections were stained either with Heidenhain-Woelcke, glutamic acid decarboxylase (GAD), calretinin, or parvalbumin. We determined the volumes of the MB and performed cell countings using stereological principles and a computerized image analysis system. The volumes of MB do not differ between schizophrenics and controls. However, in schizophrenia the number of neurons as well as the resulting neuronal densities was significantly reduced on both sides (on left side by 38.9%, on right side by 22%). No changes were seen in the number of GAD-expressing or calretinin-containing neurons, whereas the number of parvalbumin-immunoreactive MB neurons was reduced by more than 50% in schizophrenia. This cell loss (as a result of developmental malformation and/or neurodegeneration) points to a prominent involvement of the MB in the pathomorphology of schizophrenia. Parvalbumin-immunoreactive GABAergic interneurons have been reported to be diminished in schizophrenia. However, in the MB parvalbumin labels a subpopulation of glutamate/aspartate-containing neurons projecting mainly to the anterior thalamus. Thus, our data provide new evidence for impaired limbic circuits in schizophrenia.
We study how monetary, exchange-rate and other institutional arrangements are associated with pol... more We study how monetary, exchange-rate and other institutional arrangements are associated with policy makers’ preferences for inflation stability. We argue that focusing on policy intentions, represented by these preferences, constitutes a better way of evaluating policy behavior, instead of looking at inflation outcomes that may be unavoidable at times.Using a panel of 34 countries over a period of 24years we
ABSTRACT Perovskite-type mixed ionic-electronic conductor oxides are used as Solid Oxide Fuel Cel... more ABSTRACT Perovskite-type mixed ionic-electronic conductor oxides are used as Solid Oxide Fuel Cell cathodes (SOFC). A major limitation in cathode performance is the slow kinetics of oxygen exchange on the perovskite oxide surfaces, particularly at lower temperatures (T
In membrane bioreactors (MBR) for wastewater treatment, the separation of activated sludge and tr... more In membrane bioreactors (MBR) for wastewater treatment, the separation of activated sludge and treated water takes place by membrane filtration. Due to the small footprint and superior effluent quality, the number of membrane bioreactors used in wastewater treatment is rapidly increasing. A major challenge in this process is the fouling of the membranes which results in permeability decrease and the demand of chemical cleaning procedures. With the objective of a chemical-free process, the removal of the fouling layer by continuous physical abrasion was investigated. Therefore, particles (granules) were added to the activated sludge in order to realise a continuous abrasion of the fouling layer. During operation for more than 8 months, the membranes showed no decrease in permeability. Fluxes up to 40 L/(m(2) h) were achieved. An online turbidity measurement was installed for the effluent control and showed no change during this test period. For comparison, a reference (standard MBR process without granules) was operated which demonstrated permeability loss at lower fluxes and required chemical cleaning. Altogether with this process an operation at higher fluxes and no use of cleaning chemicals will increase the cost efficiency of the MBR-process.
ABSTRACT This paper introduces the special section on “New Modelling Approaches and Novel Experim... more ABSTRACT This paper introduces the special section on “New Modelling Approaches and Novel Experimental Technologies for Improved Understanding of Process Dynamics at Aquifer-Surface Water Interfaces”. It is contextualising the framework for the 27 research papers of the special section by firth identifying research gaps and imminent challenges for ecohydrological research at aquifer-surface water interfaces and then discussing the specific paper contributions on (i) New Developments in Temperature/Heat Tracing at GW-SW Interfaces, (ii) New methods to capture the temporal and spatial variability of groundwater – surface water exchange (iii) New Approaches in Modelling Aquifer-River Exchange Flow and (iv) New Concepts and Advanced Theory of Groundwater – Surface Water Exchange.
The future of nanoscale spin-based technologies hinges on a fundamental understanding and dynamic... more The future of nanoscale spin-based technologies hinges on a fundamental understanding and dynamic control of atomic-scale magnets. The role of the substrate conduction electrons on the dynamics of supported atomic magnets is still a question of interest lacking experimental insight. We characterized the temperature-dependent dynamical response of artificially constructed magnets, composed of a few exchange-coupled atomic spins adsorbed on a metallic substrate, to spin-polarized currents driven and read out by a magnetic scanning tunneling microscope tip. The dynamics, reflected by two-state spin noise, is quantified by a model that considers the interplay between quantum tunneling and sequential spin transitions driven by electron spin-flip processes and accounts for an observed spin-transfer torque effect.
The mammillary bodies (MB) are important relay nuclei within limbic and extralimbic connections. ... more The mammillary bodies (MB) are important relay nuclei within limbic and extralimbic connections. They are known to play important roles in memory formation and are affected in alcoholism and vitamin B1 deficiency. Their strategic position linking temporo-limbic to cortico-thalamic brain structures make the MB a candidate brain structure for alterations in schizophrenia. We studied 15 postmortem brains of schizophrenics and 15 matched control brains. Brain sections were stained either with Heidenhain-Woelcke, glutamic acid decarboxylase (GAD), calretinin, or parvalbumin. We determined the volumes of the MB and performed cell countings using stereological principles and a computerized image analysis system. The volumes of MB do not differ between schizophrenics and controls. However, in schizophrenia the number of neurons as well as the resulting neuronal densities was significantly reduced on both sides (on left side by 38.9%, on right side by 22%). No changes were seen in the number of GAD-expressing or calretinin-containing neurons, whereas the number of parvalbumin-immunoreactive MB neurons was reduced by more than 50% in schizophrenia. This cell loss (as a result of developmental malformation and/or neurodegeneration) points to a prominent involvement of the MB in the pathomorphology of schizophrenia. Parvalbumin-immunoreactive GABAergic interneurons have been reported to be diminished in schizophrenia. However, in the MB parvalbumin labels a subpopulation of glutamate/aspartate-containing neurons projecting mainly to the anterior thalamus. Thus, our data provide new evidence for impaired limbic circuits in schizophrenia.
We study how monetary, exchange-rate and other institutional arrangements are associated with pol... more We study how monetary, exchange-rate and other institutional arrangements are associated with policy makers’ preferences for inflation stability. We argue that focusing on policy intentions, represented by these preferences, constitutes a better way of evaluating policy behavior, instead of looking at inflation outcomes that may be unavoidable at times.Using a panel of 34 countries over a period of 24years we
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Papers by S. Krause