1,906 research outputs found
Complexation of Secondary Amides to Chromium(III): the X-Ray Structure of a Molecule with Two Modes of Monodentate Organic Amide Co-ordination
The X-ray crystal structure of the dimer [Cr{H(chba-Et)}(py)_2]_(2)·2py [H_(4)(chba-Et)= 1,2-bis(3,5-dichloro-2-hydroxybenzamido) ethane, py = pyridine] establishes, for the first time, the existence of N-co-ordination of an organic amide to Cr^III, the N-atom and carbonyl O-atom of two separate amide groups being co-ordinated to each Cr^III centre [Cr–N 2.030(6) and Cr–O 1.976(5)Å]; the potentially tetra-anionic chelating ligand leads to a variety of co-ordination modes
A multi‐scale study of the dominant catchment characteristics impacting low‐flow metrics
Low flows can impact water use and instream ecology. Therefore, reliable predictions of low-flow metrics are crucial. In this study, we assess which catchment characteristics (climate, topography, geology and landcover) can explain the spatial variability of low-flow metrics at two different scales: the regional scale and the small headwater catchment scale. For the regional-scale analysis, we calculated the mean 7-day annual minimum flow (qmin), the mean of the flow that is exceeded 95% of the year (q95), and the master recession constant (C) for 280 independent gauging stations across the Swiss Plateau and the Swiss Alps for the 2000–2018 period. We assessed the relation between 44 catchment characteristics and the three low-flow metrics based on correlation analysis and a random forest model. Low-flow magnitudes across the Swiss Plateau were positively correlated with the fraction of the area covered by sandstone bedrock or alluvium, and with the area that has a slope between 10° and 30°. Across the Swiss Alps, low-flow magnitudes were positively correlated with the fraction of area with slopes between 30° and 60°, and the area with glacial deposits and debris cover. There was good agreement between observations and predictions by the random forest regression model with the top 11 catchment characteristics for both regions: for 80% of the Swiss Plateau catchments and 60% of the Swiss Alpine catchments, we could predict the three low-flow metrics within an error of 30%. The residuals of the regression model, however, varied across short distances, suggesting that local catchment characteristics affect the variability of low-flow metrics. For the local-scale headwater catchments, we conducted 1-day snapshot field campaigns in 16 catchments during low-flow periods in 2015 and 2016. The measurements in these sub-catchments also showed that areas with sandstone bedrock and a good storage-to-river connectivity had above average low-flow magnitudes. Including knowledge on local catchment characteristics may help to improve regional low-flow predictions, however, not all local catchment characteristics were useful descriptors at larger scales
Simulation der Strahlhärtung von Stahl mit WIAS-SHarP
Die Software WIAS-SHarP zur Simulation der Oberflaechenhaertung von Stahl mit Laser- und Elektronenstrahl wurde im Rahmen eines zweijaehrigen interdisziplinaeren Forschungsprojektes entwickelt. Das zugrunde liegende mathematische Modell besteht aus einem System gewoehnlicher Differentialgleichungen zur Beschreibung der Gefuegeumwandlungen, gekoppelt mit einer nichtlinearen Waermeleitungsgleichung sowie Komponenten zur Beschreibung der Energieeinkopplung. Um eine moeglichst breite Anwendbarkeit der Software zu gewaehrleisten, wurden werkstoffspezifische Kennwerte zum Umwandlungsverhalten fuer eine grosse Anzahl praxisrelevanter Staehle bereitgestellt. Zur Modellverifikation wurden experimentelle Untersuchungen bei beteiligten Industriepartnern durchgefuehrt und mit den entsprechenden Simulationsrechnungen verglichen
Zur Messung der Waermeleitfaehigkeit von Festkoerpern insbesondere von keramischen Kernbrennstoffen bei hoechsten Temperaturen
Structures of technetium and rhenium complexes
Investigations in the 99mTc chemistry are stimulated by the search for new radiopharmaceuticals for nuclear medical applications. To understand the coordination mode of Tc with various complexing agents, macroscopic studies of technetium coordination chemistry are often performed using the low energy ß-emitting radionuclide 99Tc, which has a much longer half life (t1/2 = 2.12 x 105 years) than 99mTc, in the mg level. Investigations of Re coordination chemistry are done in conjunction with Tc studies because Re possesses chemical properties similar to those of Tc. For some chemical tasks, Re provides a non-radioactive alternative to work with Tc radioisotopes. In addition, 186Re and 188Re are of great interest to nuclear medicine as they possess nuclear properties favorable for use in therapeutic radiopharmaceuticals. Our investigations of Tc and Re coordination chemistry are toward this goal. A large series of technetium and rhenium complexes resulted from this studies have been characterized by X-ray crystal structure determinations. This survey covers the structural investigations performed by P.Leibnitz and G.Reck (BAM) from 1992 till now. It summarizes results obtained in the Rossendorf technetium group and is not intended to compete with the well-written reviews published so far
Regularization Methods for Ill-Posed Problems in Multiple Hilbert Scales
Several convergence results in Hilbert scales under different source
conditions are proved and orders of convergence and optimal orders of
convergence are derived. Also, relations between those source conditions are
proved. The concept of a multiple Hilbert scale on a product space is
introduced, regularization methods on these scales are defined, both for the
case of a single observation and for the case of multiple observations. In the
latter case, it is shown how vector-valued regularization functions in these
multiple Hilbert scales can be used. In all cases convergence is proved and
orders and optimal orders of convergence are shown.Comment: 32 pages, 2 figure
Dextran sulfate activates contact system and mediates arterial hypotension via B2 kinin receptors
Observation of the Fe spin spiral structure in Fe/Sm-Co exchange-spring bilayers by Mossbauer spectroscopy
The predictive value of the 'VMS frail older patients' for adverse outcomes in geriatric inpatients
Background/Objective: The Dutch Safety Management system (VMS) screening for frail older patients is used as a predictor for adverse outcomes. We aimed to determine the predictive value of the VMS for adverse outcomes in geriatric inpatients. Design: Retrospective cohort study in geriatric inpatients. Outcomes were institutionalization, readmission and mortality (3- and 12-months). Logistic regression analysis was performed to assess the predictive value of the number of positive VMS domains, a VMS score >= 1, and individual domains for adverse outcomes. Results: We included 477 patients. Median age was 85 years (54-99) and 37% were male. Eighty-seven % scored positive on delirium risk, 57% on fall risk, 39% on malnutrition and 64% on physical impairment. One-hundredthirty-five patients (28%) were institutionalized, 78 patients (16%) were readmitted and mortality rate was 127 (27%) at 3 months and 184 (39%) at one year. The VMS was not predictive for readmission (OR 1.6; 95%-CI 0.213.7) and mortality, (OR 0.6 95%-CI 0.2-2.0 and OR 1.1; 95%-CI 0.3-3.7). For institutionalization, delirium risk (OR 2.2; 95%-CI 1.1-4.4), physical impairment (OR 1.8; 95%-CI 1.1-2.9) and a positive score on all four domains were predictive (OR 12.1 95%-CI-1.4-101.7). Malnutrition was predictive for readmission (OR 1.74; 95%-CI 1.05-2.91) and three-month mortality (OR 1.69; 95%-CI 1.11-2.57), delirium risk for one -year mortality (OR 2.0; 95%-CI 1.0-4.0) . Conclusions: Almost all geriatric inpatients scored positive on at least one domain of the VMS. The number of positive VMS domains had some predictive value for institutionalization. Individual domains were able to predict adverse outcomes
Effective skin depth of EM fields due to large circular loop and electric dipole sources
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