Städtebauliche Kalkulation mit Decision Support Infrastructure Das Beispiel der Analyse ökonomischer Wirkungen eines kommunalen Baulandmodells

Die Kenntnis der Kosten von Stadtentwicklungs- und Wohnbaulandprojekten und die Abschätzung, inwieweit die entstehenden Lasten an Investoren übertragen werden können, ist für Kommunen von hoher Bedeutung. Diese Informationen, die in in Entscheidungen über den richtigen Standort, oder die richtige Dichte und städtebauliche Ausrichtung einer Fläche einfließen können mit dem GIS-basierten Instrument decision support infrastructure dsi analysiert und bewertet werden. Im weiteren Verlauf wird zunächst die Idee der Software Plattform dsi dargestellt. Es folgt die Beschreibung, wie dieses Instrument auch für die Kalkulationen im Zusammenhang mit kommunalen Baulandmodellen angewendet werden kann. Dazu wird der Hintergrund und die Regulierungsfunktion des Kölner Baulandmodells beschrieben und dann anhand eines Fallbeispiels Ergebnisse verschiedene Kostenübertragungen bei unterschiedlicher baulicher Dichte dargestellt

Zinc Homeostasis and isotopic fractionation in plants: a review

Aims Recent advances in mass spectrometry have dem- onstrated that higher plants discriminate stable Zn iso- topes during uptake and translocation depending on environmental conditions and physiological status of the plant. Stable Zn isotopes have emerged as a prom- ising tool to characterize the plants response to inade- quate Zn supply. The aim of this review is to build a comprehensive model linking Zn homeostasis and Zn isotopic fractionation in plants and advance our current view of Zn homeostasis and interaction with other micronutrients. Methods The distribution of stable Zn isotopes in plants and the most likely causes of fractionation are reviewed, and the interactions with micronutrients Fe, Cu, and Ni are discussed. Results The main sources of Zn fractionation in plants are i) adsorption, ii) low- and high-affinity transport phenomena, iii) speciation, iv) compartmentalization, and v) diffusion. We propose a model for Zn fraction- ation during uptake and radial transport in the roots, root-to-shoot transport, and remobilization. Conclusions Future work should concentrate on better understanding the molecular mechanisms underlying the fractionations as this will be the key to future devel- opment of this novel isotope system. A combination of stable isotopes and speciation analyses might prove a powerful tool for plant nutrition and homeostasis studies

A Sensitive Search for [N II]205 μm Emission in a z = 6.4 Quasar Host Galaxy

We present a sensitive search for the 3P1 → 3P0 ground-state fine structure line at 205 μm of ionized nitrogen ([N II]205μm) in one of the highest-redshift quasars (J1148+5251 at z = 6.42) using the IRAM 30 m telescope. The line is not detected at a (3σ) depth of 0.47 Jy km s^−1, corresponding to a [N II]205μm luminosity limit of L[N II] 7) using the Atacama Large Millimeter/submillimeter Array, for which the highly excited rotational transitions of CO will be shifted outside the accessible (sub-)millimeter bands

Gauging Radical Stabilization with Carbenes

Carbenes, including N-heterocyclic carbene (NHC) ligands, are used extensively to stabilize openshell transition metal complexes and organic radicals. Yet, it remains unknown, which carbene stabilizes a radical well and, thus, how to design radical-stabilizing C-donor ligands. With the large variety of C-donor ligands experimentally investigated and their electronic properties established, we report herein their radicalstabilizing effect. We show that radical stabilization can be understood by a captodative frontier orbital description involving π-donation to- and π-donation from the carbenes. This picture sheds a new perspective on NHC chemistry, where π-donor effects usually are assumed to be negligible. Further, it allows for the intuitive prediction of the thermodynamic stability of covalent radicals of main group- and transition metal carbene complexes

Inference of abrupt changes in noisy geochemical records using transdimensional changepoint models

International audienceWe present a method to quantify abrupt changes (or changepoints) in data series, represented as a function of depth or time. These changes are often the result of climatic or environmental variations and can be manifested inmultiple datasets as different responses, but all datasets can have the same changepoint locations/timings. The method we present uses transdimensional Markov chain Monte Carlo to infer probability distributions on the number and locations (in depth or time) of changepoints, the mean values between changepoints and, if required, the noise variance associated with each dataset being considered. This latter point is important as we generally will have limited information on the noise, such as estimates only of measurement uncertainty, and in most cases it is not practical to make repeat sampling/measurement to assess other contributions to the variation in the data.Wedescribe themain features of the approach (and describe themathematical formulation in supplementary material), and demonstrate its validity using synthetic datasets, with known changepoint structure (number and locations of changepoints) and distribution of noise variance for each dataset.We show that when using multiple data, we expect to achieve better resolution of the changepoint structure than when we use each dataset individually. This is conditional on the validity of the assumption of common changepoints between different datasets.We then apply themethod to two sets of real geochemical data, both from peat cores, taken from NE Australia and eastern Tibet. Under the assumption that changes occur at the same time for all datasets, we recover solutions consistent with those previously inferred qualitatively from independent data and interpretations. However, our approach provides a quantitative estimate of the relative probability of the inferred changepoints, allowing an objective assessment of the significance of each change

Towards an intensified process of biomass-derived monomers: The influence of HMF by-products on gold-catalyzed synthesis of 2,5-furandicarboxylic acid

The utilization of biomass and development of intensified processes are essential to establish a sustainable production of chemicals in the future. Herein, we report on a strategy that allows one to directly convert the biomass-derived platform molecule 5-(hydroxymethyl)furfural (HMF) over Au/ZrO2 in aqueous medium to 2,5-furandicarboxylic acid (FDCA), a renewable building block for biobased polymers like polyethylene furanoate. The focus lies on identifying the influence of 5-(hydroxymethyl)furfural synthesis byproducts, like unconverted sugars, levulinic acid, and formic acid as well as the remaining inorganics, on the synthesis of 2,5-furandicarboxylic acid to save the intermediate step of HMF purification. These components were added to the reaction mixture individually and in combination to study their effect. Although most of these substances lowered the FDCA yield, the reaction conditions could be optimized to produce FDCA quantitatively. Only the addition of levulinic acid led to a severe deterioration of the production of FDCA, which was attributed to poisoning of the catalyst. In a realistic technical scenario, the direct oxidation of impure HMF from unconcentrated sugar syrup in high FDCA yield (74%) was demonstrated. Catalyst stability was investigated in the presence of sugars. On the basis of these studies, highly needed recommendations for the HMF synthesis were developed to establish a more sustainable, technically feasible, and intensified process for direct FDCA production from sugars at industrial scales

Inverse Design of All-dielectric Metasurfaces with Bound States in the Continuum

Metasurfaces with bound states in the continuum (BICs) have proven to be a powerful platform for drastically enhancing light-matter interactions, improving biosensing, and precisely manipulating near- and far-fields. However, engineering metasurfaces to provide an on-demand spectral and angular position for a BIC remains a prime challenge. A conventional solution involves a fine adjustment of geometrical parameters, requiring multiple time-consuming calculations. In this work, to circumvent such tedious processes, we develop a physics-inspired, inverse design method on all-dielectric metasurfaces for an on-demand spectral and angular position of a BIC. Our suggested method predicts the core-shell particles that constitute the unit cell of the metasurface, while considering practical limitations on geometry and available materials. Our method is based on a smart combination of a semi-analytical solution, for predicting the required dipolar Mie coefficients of the meta-atom, and a machine learning algorithm, for finding a practical design of the meta-atom that provides these Mie coefficients. Although our approach is exemplified in designing a metasurface sustaining a BIC, it can, also, be applied to many more objective functions. With that, we pave the way toward a general framework for the inverse design of metasurfaces in specific and nanophotonic structures in general.Comment: 20 pages, 5 figures, Supplementary Materia

First Detection of HCO+ Emission at High Redshift

We report the detection of HCO+(1-0) emission towards the Cloverleaf quasar (z=2.56) through observations with the Very Large Array. This is the first detection of ionized molecular gas emission at high redshift (z>2). HCO+ emission is a star formation indicator similar to HCN, tracing dense molecular hydrogen gas (n(H_2) ~= 10^5 cm^{-3}) within star-forming molecular clouds. We derive a lensing-corrected HCO+ line luminosity of L'(HCO+) = 3.5 x 10^9 K km/s pc^2. Combining our new results with CO and HCN measurements from the literature, we find a HCO+/CO luminosity ratio of 0.08 and a HCO+/HCN luminosity ratio of 0.8. These ratios fall within the scatter of the same relationships found for low-z star-forming galaxies. However, a HCO+/HCN luminosity ratio close to unity would not be expected for the Cloverleaf if the recently suggested relation between this ratio and the far-infrared luminosity were to hold. We conclude that a ratio between HCO+ and HCN luminosity close to 1 is likely due to the fact that the emission from both lines is optically thick and thermalized and emerges from dense regions of similar volumes. The CO, HCN and HCO+ luminosities suggest that the Cloverleaf is a composite AGN--starburst system, in agreement with the previous finding that about 20% of the total infrared luminosity in this system results from dust heated by star formation rather than heating by the AGN. We conclude that HCO+ is potentially a good tracer for dense molecular gas at high redshift.Comment: 5 pages, 3 figures, ApJL, in press (accepted May 17, 2006

Fundamental Investigation of Wave Propagation inside IC-Striplines upon Excitation with Hertzian Dipole Moments

To characterize the electromagnetic compatibility (EMC) of integrated circuits (ICs), especially the radiated emissions in the near field, transversal electromagnetic cell (TEM cell) or IC-stripline measurements (IEC 61967) are utilized. Due to the ongoing miniaturization and the increasing operating frequencies, accurate EMC characterization of ICs is becoming more important to achieve first-time-right designs. In order to avoid expensive redesigns, the prediction of these measurements in terms of a simulation workflow would be of high interest. Because of the high computational burden needed to conduct 3D full-wave finite element (FEM) simulations of both the device under test (DUT) and the measurement system, an equivalent representation of the DUT by means of analytical incident fields, such as Hertzian dipole moments, can be considered. In order to develop an order-reduced model of this kind, it is essential to have a solid understanding of the coupling and wave propagation effects inside the measurement systems. In the present paper, a fundamental investigation of the coupling paths between an IC-stripline and electric or magnetic dipole moments is presented and the results are compared to the existing analytical models. The results show that these analytical models, originally developed for TEM cells, are only partially valid for IC-striplines. It has also been shown that even for simple test structures, such as loop and monopole antennas, the representation in terms of one single dipole moment is insufficient