A model measurements comparison of atmospheric forcing and surface fluxes of the Baltic Sea

Observed basic meteorological quantities, heat and radiation fluxes from three different measurement stations in the Baltic Sea are compared with model data of the coupled sea-ice-ocean model BSIOM in order to evaluate the atmospheric forcing, corresponding surface fluxes and the sea surface response. Observational data were made available from the BASIS winter campaigns in 1998 and 2001 as well as from the r/v "Alkor" cruise in June 2001. Simulated fluxes were calculated from prescribed atmospheric forcing provided from the SMHI meteorological database and modelled sea surface temperatures. The comparison of these fluxes with observations demonstrates a strong correlation, even though mean differences in sensible heat fluxes range from 4 to 12 W m-2 in winter and -25 W m-2 in the June experiment. Differences in latent heat fluxes range from -10 to 23 W m-2. The short-wave radiation flux used as model forcing is on average 15 W m-2 less than the corresponding observations for the winter experiments and 40 W m-2 for the June experiment. Differences in net long-wave radiation fluxes range from -5 to 12 W m-2 in winter and -62 W m-2 for the June experiment. The correspondence between measured and calculated momentum fluxes is very high, which confirms the usability of our model component for calculating surface winds and wind stresses from the atmospheric surface pressure

Part I Photochemical Deconjugation Reactions Of 3-alkyl-2-cyclohexenones Part Ii Biradicals In 2+2 Photocycloaddition Reactions Of 2-cyclopentenone

Part I. Ultraviolet irradiation of 3-methyl-2-cyclohexenones leads to the formation of the deconjugated exocyclic isomers in low quantum yields. The reaction proceeds via the triplet excited state of the enone but the mechanism has not been determined satisfactorily. Part I of this thesis describes evidence for acid catalysis of the reaction. The presence of small quantities of carboxylic acid greatly enhances the quantum yield of the deconjugation reaction. The proposal of the intermediacy of a carbocation was supported by the detection of products derived from addition to the conjugate base of the acid to the carbocation. In addition, the presence of 10% methanol in the irradiation mixture led to the formation of products derived from addition of the alcohol to the carbocation. From the kinetic data obtained the lifetime of the trans-enone was determined to be at least 1 {dollar}\mu{dollar}s.;The presence of alkenes in the reaction mixture led to a decrease in the quantum yield of the deconjugation reaction; instead products derived from 2+2 cycloaddition between the enone and the alkene were observed.;Contrary to literature reports it was found that the deconjugation reaction proceeds not only for 3-methyl substituted 2-cyclohexenones but also for 3-ethyl-5,5-dimethyl-2-cyclohexenone. Irradiation of the latter compound led to the formation of two geometrical isomers of the exocyclic deconjugated isomer. No deconjugation products were found in the irradiation of 3-isopropyl substituted 2-cyclohexenones which was believed to be due to steric hindrance to formation of the trans-enone. Acid catalysis was also found in the deconjugation reaction of R-10-methyl-{dollar}\Delta\sp{lcub}1,9{rcub}{dollar}-2-octalone, a bicyclic cyclohexenone.;Part II. Irradiation of 2-cyclopentenone in the presence of alkenes leads to the formation of cyclobutane ring containing 2+2 cycloadducts. The reaction proceeds via the triplet excited state of the enone which is quenched by the alkene to give an intermediate triplet 1,4-biradical.;Irradiation of the enone with vinylcyclopropane led to the detection of products derived from radical rearrangement of the intermediate biradical in addition to 2+2 cycloadducts. From the product distribution the lifetime of the triplet 1,4-biradical intermediate in this reaction was estimated to be 20-50 ns.;A number of differently substituted diketones based on the bicyclo (3.3) octane system were synthesized. It was hoped that these would undergo a photochemical decarbonylation reaction generating the desired biradicals; however, only the cyano substituted diketones underwent the expected reaction. The results suggest that the cycloaddition reaction regiochemistry is indeed determined by the fates of the biradical intermediates rather than their relative rates of formation. (Abstract shortened by UMI.

Environment applications for ion mobility spectrometry

The detection of environmentally important polychlorinated aromatics by ion mobility spectrometry (IMS) was investigated. Single polychlorinated biphenyl (PCB) isomers (congeners) having five or more chlorine atoms were reliably detected in isooctane solution at levels of 35 ng with a Barringer IONSCAN ion mobility spectrometer operating in negative mode; limits of detection (LOD) were extrapolated to be in the low ng region. Mixtures of up to four PCB congeners, showing characteristic multiple peaks, and complex commercial mixtures of PCBs (Aroclors) were also detected. Detection of Aroclors in transformer oil was suppressed by the presence of the antioxidant BHT (2,6-di-t-butyl4-methylphenol) in the oil. The wood preservative pentachlorophenol (PCP) was easily detected in recycled wood shavings at levels of 52 ppm with the IONSCAN; the LOD was extrapolated to be in the low ppm region

Die Handelskosten von Sachsen

Die regionale Struktur und das Volumen der sächsischen Exporte und Importe erklären sich nicht nur durch die relativen Kostenunterschiede zwischen Sachsen und den Handelspartnern; mitentscheidend sind auch die Handelskosten für Exporte und Importe der sächsischen Wirtschaft. Unter Handelskosten werden Transportkosten, Kosten des Grenzübergangs der Ware und Distributionskosten, die im Empfängerland entstehen, verstanden. Jüngste empirische Arbeiten zu Kosten im internationalen Handel zeigen ein überraschendes Ergebnis: Für die OECD-Staaten entstehen im Durchschnitt Handelskosten, die einem Aufschlag von über 170 % entsprechen. Handelskosten können als Aufschlag, d. h. als ein Wertzoll aufgefasst werden. Unser Beitrag verwendet einen neuen Handelskostenindex, um die Handelskosten in Form eines Zolläquivalents für die sächsische Wirtschaft zu ermitteln. Im Jahr 1992 lag der durchschnittliche gewichtete Aufschlag für mit Sachsen gehandelte Waren bei 1,70. Im Jahr 2008 nahm dieser Aufschlag der Handelskosten in etwa den Wert eins an. Damit muss zum ursprünglichen Warenwert noch einmal der gleiche Wert für die Kosten des Handels aufgebracht werden.Außenwirtschaft; Transaktionskosten; Transportkosten; Informationskosten; Außenhandelsbeschränkung; Vergleich; Sachsen; OECD-Staaten

The build-up of coercive capacities

Do governments’ military build-ups foster the outbreak of intrastate violence? This article investigates the impact of governments’ arms imports on the onset of intrastate conflicts. There is scant empirical research on the role of the external acquisition of coercive technologies, and even fewer studies explore the respective causal mechanisms of their consequences. We argue that the existing literature has not adequately considered the potential simultaneity between conflict initiation and arms purchases. In contrast, our study explicitly takes into account that weapon inflows may not only causally induce conflicts but may themselves be caused by conflict anticipation. Following a review of applicable theoretical models to derive our empirical expectations, we offer two innovative approaches to surmount this serious endogeneity problem. First, we employ a simultaneous equations model that allows us to estimate the concurrent effects of both arms imports on conflict onsets and conflict onsets on imports. Second, we are the first to use an instrumental variable approach that uses the import of weapon types not suitable for intrastate conflict as instruments for weapon imports that are relevant for fighting in civil wars. Relying on arms transfer data provided by the Stockholm International Peace Research Institute for the period 1949-2013, we provide estimates for the effect of imports on civil war onset. Our empirical results clearly show that while arms imports are not a genuine cause of intrastate conflicts, they significantly increase the probability of an onset in countries where conditions are notoriously conducive to conflict. In such situations, arms are not an effective deterrent but rather spark conflict escalation

Position controlled self-catalyzed growth of GaAs nanowires by molecular beam epitaxy

GaAs nanowires are grown by molecular beam epitaxy using a self-catalyzed, Ga-assisted growth technique. Position control is achieved by nano-patterning a SiO2 layer with arrays of holes with a hole diameter of 85 nm and a hole pitch varying between 200 nm and 2 \mum. Gallium droplets form preferentially at the etched holes acting as catalyst for the nanowire growth. The nanowires have hexagonal cross-sections with {110} side facets and crystallize predominantly in zincblende. The interdistance dependence of the nanowire growth rate indicates a change of the III/V ratio towards As-rich conditions for large hole distances inhibiting NW growth.Comment: 9 pages, 4 figure

Model-driven optimisation of monitoring system configurations for batch production

The increasing need to monitor asset health and the deployment of IoT devices have driven the adoption of non-desctructive testing methods in the industry sector. In fact, they constitute a key to production efficiency. However, engineers still struggle to meet requirements sufficiently due to the complexity and cross-dependency of system parameters. In addition, the design and configuration of industrial monitoring systems remains dependent on recurring issues: data collection, algorithm selection, model configuration and objective function modelling. In this paper, we shine a light on impact factors of machine vision and signal processing in industrial monitoring, from sensor configuration to model development. Since system design requires a deep understanding of the physical characteristics, we apply graph-based design languages to improve the decision and configuration process. Our model and architecture design method are adapted for processing image and signal data in highly sen sitive installations to increase transparency, shorten time-to-production and enable defect monitoring in environments with varying conditions. We explore the potential of model selection, pipeline generation and data quality assessment and discuss their impact on representative manufacturing processes