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Search Results: 1 - 10 of 1447 matches for " Jochen Theloke "
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Can we evaluate a fine-grained emission model using high-resolution atmospheric transport modelling and regional fossil fuel CO2 observations?
Felix R. Vogel,Balendra Thiruchittampalam,Jochen Theloke,Roberto Kretschmer
Tellus B , 2013, DOI: 10.3402/tellusb.v65i0.18681
Abstract: Quantifying carbon dioxide emissions from fossil fuel burning (FFCO2) is a crucial task to assess continental carbon fluxes and to track anthropogenic emissions changes in the future. In the present study, we investigate potentials and challenges when combining observational data with simulations using high-resolution atmospheric transport and emission modelling. These challenges concern, for example, erroneous vertical mixing or uncertainties in the disaggregation of national total emissions to higher spatial and temporal resolution. In our study, the hourly regional fossil fuel CO2 offset (ΔFFCO2) is simulated by transporting emissions from a 5 min×5 min emission model (IER2005) that provides FFCO2 emissions from different emission categories. Our Lagrangian particle dispersion model (STILT) is driven by 25 km×25 km meteorological data from the European Center for Medium-Range Weather Forecast (ECMWF). We evaluate this modelling framework (STILT/ECMWF+IER2005) for the year 2005 using hourly ΔFFCO2 estimates derived from 14C, CO and 222Radon (222Rn) observations at an urban site in south-western Germany (Heidelberg). Analysing the mean diurnal cycles of ΔFFCO2 for different seasons, we find that the large seasonal and diurnal variation of emission factors used in the bottom-up emission model (spanning one order of magnitude) are adequate. Furthermore, we show that the use of 222Rn as an independent tracer helps to overcome problems in timing as well as strength of the vertical mixing in the transport model. By applying this variability correction, the model-observation agreement is significantly improved for simulated ΔFFCO2. We found a significant overestimation of ΔFFCO2 concentrations during situations where the air masses predominantly originate from densely populated areas. This is most likely caused by the spatial disaggregation methodology for the residential emissions, which to some extent relies on a constant per capita-based distribution. In the case of domestic heating emissions, this does not appear to be sufficient.
Competition of Intermediaries in a Differentiated Duopoly  [PDF]
Sonja Brangewitz, Jochen Manegold
Theoretical Economics Letters (TEL) , 2016, DOI: 10.4236/tel.2016.66124
Abstract: On an intermediate goods market with asymmetric production technologies as well as vertical and horizontal product differentiation, we analyze the influence of simultaneous competition for resources and customers. The intermediaries face either price or quantity competition on the output market and a monopolistic, strategically acting supplier on the input market. We find that there exist quality and productivity differences such that for quantity competition only one intermediary is willing to procure inputs from the input supplier, while for price competition both intermediaries are willing to purchase inputs. Moreover, the well-known welfare advantage of price competition can in general be no longer confirmed in our model with an endogenous input market and asymmetric intermediaries.
Renormalization by Projection: On the Equivalence of the Bloch-Feshbach Formalism and Wilson's Renormalization
Jochen Mueller,Jochen Rau
Physics , 1995, DOI: 10.1016/0370-2693(96)00964-1
Abstract: We employ projection operator techniques in Hilbert space to derive a continuous sequence of effective Hamiltonians which describe the dynamics on successively larger length scales. We show for the case of \phi^4 theory that the masses and couplings in these effective Hamiltonians vary in accordance with 1-loop renormalization group equations. This is evidence for an intimate connection between Wilson's renormalization and the venerable Bloch-Feshbach formalism.
Superconductivity in Layered Organic Metals
Jochen Wosnitza
Crystals , 2012, DOI: 10.3390/cryst2020248
Abstract: In this short review, I will give an overview on the current understanding of the superconductivity in quasi-two-dimensional organic metals. Thereby, I will focus on charge-transfer salts based on bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET for short). In these materials, strong electronic correlations are clearly evident, resulting in unique phase diagrams. The layered crystallographic structure leads to highly anisotropic electronic as well as superconducting properties. The corresponding very high orbital critical field for in-plane magnetic-field alignment allows for the occurrence of the Fulde–Ferrell– Larkin–Ovchinnikov state as evidenced by thermodynamic measurements. The experimental picture on the nature of the superconducting state is still controversial with evidence both for unconventional as well as for BCS-like superconductivity.
Five years REACH
Jochen Flasbarth
Environmental Sciences Europe , 2012, DOI: 10.1186/2190-4715-24-32
Abstract: On June, 1st, we celebrated five years experience since the European REACH Regulation [1] entered into force. The experience is mainly positive: In nearly 29,000 technical dossiers for approximately 5,900 substances, registrants submitted a huge amount of information on uses, properties, hazards, toxicological and ecotoxicological effects to the European Chemicals Agency (ECHA) in Helsinki. These registrations include all substances with a manufacturing or import volume of more than 1,000 tons per year and registrant, all substances that are carcinogenic, mutagenic or toxic for reproduction which are intended to stay on the EU-market, and some more important chemicals.It was a really hard challenge for companies to meet the deadline for registration and the REACH information requirements. Although we, and also ECHA [2] are not completely satisfied with the quality of many dossiers and the way the information requirements were interpreted, we’d like to congratulate the world-wide chemical industry for managing this challenge in time.The task for authorities is to prioritise substances for regulatory activities. For ECHA this is the dossier evaluation, for Member States authorities the substance evaluation and for all authorities elaborating proposals to identify substances of very high concern (SVHC), and candidates for authorisation and restrictions. Some of these tasks are already in the beginning (e.g. substance evaluation), others are ongoing, (e.g. the identification of SVHC). By September, 1st, 84 SVHC are included in the candidate list, and 14 substances are included in Annex XIV and therefore will be subject for authorisation in future. To elaborate the proposals and to agree the measures in the Member State Committee was not an easy task – and therefore we congratulate also the Member States authorities, and especially ECHA.Reflecting five years experiences, we see options for some improvements. Among other suggestions, the most important is to strengthen th
Statistical filtering for NMR based structure generation
Jochen Junker
Journal of Cheminformatics , 2011, DOI: 10.1186/1758-2946-3-31
Abstract: Nuclear Magnetic Resonance is the most common tool used for the structure elucidation of new compounds. The used 2D NMR experiments like COSY, HSQC, and 13C-HMBC deliver correlation information between atoms that can be translated into connectivity information. Out of these, correlation information from COSY and HSQC experiments can be transcribed directly into connectivity between atoms. But the 13C-HMBC correlations need more attention because of their ambiguity and complexity. Hence the difficulty of the structure elucidation problem depends more on the type of the investigated molecule than on its size. Saturated compounds can usually be assigned unambiguously using mainly COSY and some 13C-HMBC data, whereas condensed heterocycles are problematic due to their lack of protons that could show interatomic connectivities. This ambiguity has driven the development of different software packages to aid in the interpretation of the 13C-HMBC correlation data [1-19] as much as the development of additional correlation experiments [20,21].When the observed connectivity information is used as input for the structure generation program COCON[3,22-24] it will create all compatible constitutional assignments. In the case of unsaturated molecules COCON will usually generate a very large number of possible solutions. Since the solutions will then have to be checked manually for their chemical feasibility and sense, Different efforts have been made to reduce the number solutions. Among others, ranking of the constitutional assignments by chemical shift deviation and/or substructural elements have been tested [25,26] integrated to COCON runs. Unfortunately, the described software could not be made available for the online version of COCON (WEBCOCON at http://cocon.nmr.de webcite), since it uses data protected by Intellectual Property. A different way of handling the result set had to be chosen, and the statistical filter was implemented.The idea behind the filter is, to compare
Theoretical NMR correlations based Structure Discussion
Jochen Junker
Journal of Cheminformatics , 2011, DOI: 10.1186/1758-2946-3-27
Abstract: Nuclear Magnetic Resonance allied with Elemental analysis or high resolution Mass Spectroscopy are the most common tools used for the structure elucidation of new compounds. The used 2D NMR experiments like COSY, HSQC, and 13C-HMBC deliver correlation information between atoms that can be translated into connectivity information. Out of these, correlation information from COSY and HSQC experiments can be transcribed directly into connectivity between atoms. But the 13C-HMBC correlations need more attention because of their ambiguity and complexity. Hence the difficulty of the structure elucidation problem depends more on the type of the investigated molecule than on its size [1]. Saturated compounds can usually be assigned unambiguously using mainly COSY and some 13C-HMBC data, whereas condensed heterocycles are problematic due to their lack of protons that could show interatomic connectivities. This ambiguity has driven the development of different software packages to aid in the interpretation of the 13C-HMBC correlation data [2-20] as much as the development of additional correlation experiments [21,22].Most of these approaches have in common that they work only based on experimental NMR correlation data. COCON [1,4,23,24] has recently been extended with the capability to create a theoretical NMR correlation data set, based on a molecule's suggested constitution. The theoretical data set is used as input data for the structure elucidation software COCON. The resulting set of constitutional assignments indicates how unambiguous NMR would have been able to describe the originally suggested molecule. The freely accessible online version of COCON (WEBCOCON at http://cocon.nmr.de webcite) offers this analysis as "Alternative Constitutions".The data derived from the NMR correlation spectra is the result of magnetization transfer via scalar coupling between the atoms in the molecule of interest. Since the scalar coupling is based on the interatomic bonds, the correlatio
Diagnostic and Prognostic Information Provided by a High Sensitivity Assay for Cardiac Troponin T
Jochen Jarausch
Journal of Medical Biochemistry , 2010, DOI: 10.2478/v10011-010-0041-8
Abstract: Cardiac troponins (cTns) are the preferred biomarkers for the diagnosis of acute myocardial infarction, assessment of risk and prognosis, and for determination of antithrombotic and revascularization strategy in patients with acute coronary syndromes. The implementation of high sensitivity cTn assays into the clinical routine has increased the number of patients diagnosed with myocardial infarction. In addition, the number of patients with elevated cTn levels that cannot be explained by acute ischemic injury was increased, which is observed in patients with chronic heart disease and other nonischemic cardiac injury or in patients with impaired renal function. The new definition of myocardial infarction provides support for the interpretation of elevated cTn measured with high sensitivity cTn assays in patients with suspected acute coronary syndrome. This review will summarize clinical studies with the recently introduced high sensitivity cTnT assay (TnT hs) with reference to recent experience with high sensitivity cTn assays in general.
Gethmann-Siefert A., Mittelstra J. (eds): Die Philosophie und die Wissenschaften. Zum Werk Oskar Beckers
Jochen Sattler
Poiesis & Praxis , 2004, DOI: 10.1007/s10202-003-0039-0
Abstract:
The symptom checklist-27-plus (SCL-27-plus): a modern conceptualization of a traditional screening instrument
Hardt, Jochen
GMS Psycho-Social-Medicine , 2008,
Abstract: Background: The symptom checklist SCL-27-plus is a short, multidimensional screening instrument for mental health problems. It contains five scales on current symptoms: depressive, vegetative, agoraphobic, and sociophobic symptoms and pain; a global severity index (GSI-27); a lifetime assessment for depressive symptoms; and a screening question for suicidality.Method: A reformulated version of screening items constituted a survey of n=374 students. Therefore, a total of 76 items was formulated and presented to the students within a questionnaire booklet, that could be filled out at home.Results: All scales of the SCL-27-plus showed good to satisfactory reliability (i.e. .90 ≥ Cronbach’s a ≥ .70). The distributions of the scales were less skewed than in older versions of the symptom checklists and scale inter-correlations were lower. The scale “symptoms of mistrust” could not be retained.Conclusion: The SCL-27-plus demonstrates a clear improvement over the SCL-27. Test-statistical properties were improved. In addition, the supplementation by a lifetime scale for depression and a screener for suicidality shall help the clinician as well as the epidemiologist.
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