Search results for "ddc:"
showing 10 items of 3080 documents
Estimation of Vegetation Structure Parameters From SMAP Radar Intensity Observations
2021
In this article, we present a multipolarimetric estimation approach for two model-based vegetation structure parameters (shape A and orientation distribution ψ of the main canopy elements). The approach is based on a reduced observation set of three incoherent (no phase information) polarimetric backscatter intensities (|S HH | 2 , |S HV | 2 , and |S VV | 2 ) combined with a two-parameter (A P and ψ) discrete scatterer model of vegetation. The objective is to understand whether this confined set of observations contains enough information to estimate the two vegetation structure parameters from the L-band radar signals. In order to disentangle soil and vegetation scattering influences on th…
Security in Niamey : an anthropological perspective on policing and an act of terrorism in Niger
2012
ABSTRACTThe abduction of two Frenchmen in January 2011 in Niamey's supposedly most secure neighbourhood has led many to question the functioning of the city's security apparatus. This paper analyses Niamey's security landscape, initially from an historical and then from a spatial perspective. It argues that for a comprehensive analysis of security, we must first decentre our perspective on security construction, and thus take informal non-organised modes of policing just as seriously as policing by state and vigilante organisations; and second, take into account the inseparability of sociality and security, a fragile balance of trust and acceptable risk. In conclusion I argue that this focu…
Petrogenetic evolution of metabasalts and metakomatiites of the lower Onverwacht Group, Barberton Greenstone Belt (South Africa)
2019
A well-preserved sequence, by Archean standards, of mantle-derived metabasalts and metakomatiites forms large parts of the lower Onverwacht Group of the Barberton Greenstone Belt (South Africa). To elucidate the origin of mafic and ultramafic rocks from this 3.55 to 3.45 Ga sequence, we present a comprehensive geochemical dataset including major and trace elements as well as Lu-Hf and Sm-Nd isotope compositions for a variety of metavolcanic rocks. These include metabasalts of the amphibolite-facies Sandspruit and Theespruit Formations as well as metabasalts and metakomatiites of the lower greenschist-facies Komati Formation. Based on their incompatible trace element patterns, the basalts of…
Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 2: A…
2012
Abstract. For reconstructing environmental change in terrestrial realms the geochemistry of fossil bioapatite in bones and teeth is among the most promising applications. This study demonstrates that alkaline earth elements in enamel of Hippopotamids, in particular Ba and Sr are tracers for water provenance and hydrochemistry. The studied specimens are molar teeth from Hippopotamids found in modern and fossil lacustrine settings of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by ca. two orders of magnitude for Ba (120–9336 μg g−1) as well as for Sr (9–21…
Battery characterization via eddy-current imaging with nitrogen-vacancy centers in diamond
2021
Sensitive and accurate diagnostic technologies with magnetic sensors are of great importance for identifying and localizing defects of rechargeable solid batteries in a noninvasive detection. We demonstrate a microwave-free AC magnetometry method with negatively charged NV centers in diamond based on a cross-relaxation feature between NV centers and individual substitutional nitrogen (P1) centers occurring at 51.2 mT. We apply the technique to non-destructive solid-state battery imaging. By detecting the eddy-current-induced magnetic field of the battery, we distinguish a defect on the external electrode and identify structural anomalies within the battery body. The achieved spatial resolut…
Rapid online solid-state battery diagnostics with optically pumped magnetometers
2020
Applied Sciences 10(21), 7864 (2020). doi:10.3390/app10217864
Flax, Basalt, E-Glass FRP and Their Hybrid FRP Strengthened Wood Beams: An Experimental Study
2019
In this study, the structural behavior of small-scale wood beams externally strengthened with various fiber strengthened polymer (FRP) composites (i.e., flax FRP (FFRP), basalt FRP (BFRP), E-glass FRP (&ldquo
Mentoring of newly qualified teachers. A bilateral comparison between Germany and Finland
2017
Mentoring stellt in der Begleitung von in den Beruf einsteigenden Lehrpersonen eine international gängige Praxis dar. Ausgehend von theoretischen und empirisch fundierten Annahmen wird in diesem Beitrag der Ansatz der practice architectures genutzt, um Formen des Mentorings in Deutschland und Finnland im Hinblick auf länderspezifische Verständnisse vom Berufseinstieg von Lehrpersonen und deren Professionalisierung zu untersuchen. (DIPF/Orig.) Internationally, mentoring is a well-recognized practice in supporting newly qualified teachers. Based on theoretical and empirical understanding, this paper compares mentoring practices in two countries: Germany and Finland. The theoretical framework …
Interaction of Au16 Nanocluster with Defects in Supporting Graphite: A Density-Functional Study
2011
Soft-landed adsorption of Au-16 on bilayered graphene is investigated using density functional theory. The orientation of the Au-16 cluster and number of neighboring surface vacancies affect the overall structural and electronic properties of the cluster. The results of the PBE, vdW-DF, and vdW-DF2 exchange-correlation functionals are compared for the cluster-substrate interaction for systems with and without defects. In the presence of defects size two and greater, an Au atom adsorbs into the topmost graphene layer; this strongly influences the binding energy (>3 eV), while inducing substantial bending in the carbon plane and altering electronic properties of the system. Though the T-d-sym…
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ?accidental cell death' (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. "Regulated cell death" (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to…