490 research outputs found

    Testing and improving the spatial and temporal resolution of satellite, radar and station data for hydrological applications

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    This doctoral thesis is based on three publications (two peer-reviewed, one submitted). Its objective was to test existing methods and to develop innovative methods for generating highly resolved climate data with focus on the spatio-temporal distribution of precipitation as both, the spatial and temporal resolution as well as the length of such data sets are limited. For this purpose, satellite and radar-based remote sensing data, ground-based station data, and modelling methods were applied and combined. The Free State of Saxony (Germany) served as an investigation area as its mountainous regions are prone to heavy precipitation events and related (flash) floods like e.g., in 2002, in 2010, and in 2013. Two approaches were developed to generate hourly data when there are no station data available or only daily data. The first approach applies four different algorithms to estimate area-wide rain rates by using the satellite data of Meteosat Second Generation (MSG-1) and compares them to the gauge adjusted radar data product RADOLAN RW. The analyses of five spatial und six temporal integration steps by means of four fit scores and statistical relations show a stepwise improvement. That means, the integration leads to increasing probability of detection (POD) and critical success index (CSI), decreasing false alarm ratio (FAR) and Bias, and improved statistical relations especially for heavy rain rates. The best results are achieved for the lowest resolution of 120 km × 120 km and 24 h. However, this resolution is too low for applications in (flash) flood risk management for small and medium sized catchments. Such satellite-based estimated rain rates may serve as a data source for unobserved regions or as an indicator for large catchments or longer periods. A second approach comprises the newly developed Euclidean distance model (EDM) that generates hourly climate data by means of a temporal disaggregation procedure. The delivered data are point data for the climate variables temperature, precipitation, sunshine duration, relative humidity, and wind speed. They show high correlations and conserve (i) the statistics in comparison to the observed hourly data and (ii) also the consistency over all disaggregated climate elements. The results reveal that the EDM performs best for climate elements with a continuous diurnal cycle like temperature, for the winter half-year, and when the basic climate stations are characterised by similar climate conditions. The EDM proves to be a very robust, flexible and fast working model. Hence, the work presented here succeeded in developing two innovative locally-independent approaches that are applicable to the climate data of any region or station without complex model parametrisation. Simultaneously, the method can be applied to future daily climate data allowing the generation of hourly data that are needed for climate impact models.Diese Dissertation basiert auf drei Publikationen (zwei begutachtet, eine eingereicht). Ziel war es, existierende Methoden zur Generierung hochaufgelöster Klimadaten zu untersuchen und innovative Methoden zu entwickeln mit dem Fokus auf der raumzeitlichen Niederschlagsverteilung, da sowohl die rĂ€umliche und zeitliche Auflösung als auch die LĂ€nge solcher Datenreihen begrenzt sind. HierfĂŒr wurden satelliten- und radarbasierte Fernerkundungsdaten, Bodenstationsdaten sowie Modellierungsverfahren angewendet und kombiniert. Als Untersuchungsgebiet wurde der Freistaat Sachsen (Deutschland) gewĂ€hlt, da dessen Gebirgsregionen starkregen- und damit hochwassergefĂ€hrdet sind, wie bei den Hochwasserereignissen von 2002, 2010 und 2013 sichtbar wurde. Es wurden zwei AnsĂ€tze entwickelt, die die Generierung von Stundendaten ermöglichen, wenn keine Daten oder nur Tagesdaten vorhanden sind. Der erste Ansatz verwendet vier verschiedene Algorithmen zum AbschĂ€tzen flĂ€chendeckender NiederschlagsintensitĂ€ten unter Verwendung der Daten des Satelliten Meteosat Second Generation (MSG-1) und vergleicht diese mit den an Bodenstationsdaten angeeichten Radardaten des RADOLAN RW Produktes. Die Analysen von fĂŒnf rĂ€umlichen und sechs zeitlichen Integrationsstufen mit Hilfe von vier Fit Scores und statistischer Kennwerte zeigen eine schrittweise Verbesserung der Ergebnisse. Das heißt, dass durch Integration steigende Werte der probability of detection (POD) und des critical success index (CSI), sinkende Werte der false alarm ratio (FAR) und des Bias sowie verbesserte statistische Kennwerte erreicht werden. Dies gilt insbesondere fĂŒr StarkniederschlagsintensitĂ€ten. Die besten Ergebnisse werden bei der niedrigsten Auflösung von 120 km × 120 km und 24 h erreicht. Jedoch ist diese Auflösung fĂŒr Anwendungen des Hochwasserrisikomanagements kleiner und mittlerer Einzugsgebiete zu gering. Solche satellitenbasierten NiederschlagsintensitĂ€ten können als Datenquelle fĂŒr unbeobachtete Regionen oder als Indikator fĂŒr große Einzugsgebiete oder lĂ€ngere Zeitintervalle dienen. Ein zweiter Ansatz beinhaltet das neu entwickelte Euclidean distance model (EDM), das mittels zeitlicher Disaggregierung stĂŒndliche Klimadaten generiert. Die erzeugten Daten sind punktbezogene Daten der Klimavariablen Temperatur, Niederschlag, Sonnenscheindauer, relative Feuchte und Windgeschwindigkeit. Sie weisen hohe Korrelationen auf und sie wahren (i) die statistischen KenngrĂ¶ĂŸen im Vergleich mit den beobachteten Stundendaten und (ii) die Konsistenz ĂŒber alle Klimaelemente hinweg. Die Ergebnisse zeigen, dass das EDM fĂŒr Klimaelemente mit einem kontinuierlichen Tagesgang, wie z.B. die Temperatur, fĂŒr das Winterhalbjahr und bei der Verwendung von Basisstationen mit Ă€hnlicher klimatischer Charakteristik die besten Ergebnisse liefert. Das EDM erweist sich als ein sehr robustes, flexibles und schnell arbeitendes Modell. Somit ist es mit der hier vorliegenden Arbeit gelungen, zwei innovative AnsĂ€tze zu entwickeln, die ohne komplexe Modellparametrisierung auf Daten einer jeden Klimaregion oder Klimastation angewendet werden können

    A Phosphine Functionalized ÎČ‐Diketimine Ligand for the Synthesis of Manifold Metal Complexes

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    One-size-fits-all: A ÎČ-diketimine ligand and its corresponding anion, forming a PNNP-type pocket, can stabilize various coordination polyhedral. A complete series of complexes forming seven different coordination polyhedral and coordination numbers ranging from 2 to 6 were realized. A bis(diphenyl)-phosphine functionalized ÎČ-diketimine (PNac-H) was synthesized as a flexible ligand for transition metal complexes. The newly designed ligand features symmetrically placed phosphine moieties around a ÎČ-diketimine unit, forming a PNNP-type pocket. Due to the hard and soft donor atoms (N vs. P) the ligand can stabilize various coordination polyhedra. A complete series ranging from coordination numbers 2 to 6 was realized. Linear, trigonal planar, square planar, tetrahedral, square pyramidal, and octahedral coordination arrangements containing the PNac-ligand around the metal center were observed by using suitable metal sources. Hereby, PNac-H or its anion PNac− acts as mono-, bi- and tetradendate ligand. Such a broad flexibility is unusual for a rigid tetradentate system. The structural motifs were realized by treatment of PNac-H with a series of late transition metal precursors, for example, silver, gold, nickel, copper, platinum, and rhodium. The new complexes have been fully characterized by single crystal X-ray diffraction, NMR, IR, UV/Vis spectroscopy, mass spectrometry as well as elemental analysis. Additionally, selected complexes were investigated regarding their photophysical properties. Thus, PNac-H proved to be an ideal ligand platform for the selective coordination and stabilization of various metal ions in diverse polyhedra and oxidation states

    Grundwasser - Altlasten - Boden aktuell

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    Neun FachbeitrĂ€ge dokumentieren Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden. Die Inhalte reichen vom Interesse aus Namibia fĂŒr diese Themenbereiche ĂŒber verschiedene Auswertungen von Hintergrundwerten und Hochwasser 2013 bis hin zu Planungen im Bereich Bodendauerbeobachtung in Sachsen. Einzelerkenntnisse zu WĂŒlknitz bzw. zum Tagebau Witznitz werden in dem Heft fortgefĂŒhrt

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

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    Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI
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