Institute of Physical Chemistry of Combustion

Stuttgart, Germany

Institute of Physical Chemistry of Combustion

Stuttgart, Germany
Time filter
Source Type

Heuer A.,Institute of Physical Chemistry of Combustion | Rubner O.,Institute of Physical Chemistry of Combustion
PLoS ONE | Year: 2014

We present a systematic approach for prediction purposes based on panel data, involving information about different interacting subjects and different times (here: two). The corresponding bivariate regression problem can be solved analytically for the final statistical estimation error. Furthermore, this expression is simplified for the special case that the subjects do not change their properties between the last measurement and the prediction period. This statistical framework is applied to the prediction of soccer matches, based on information from the previous and the present season. It is determined how well the outcome of soccer matches can be predicted theoretically. This optimum limit is compared with the actual quality of the prediction, taking the German premier league as an example. As a key step for the actual prediction process one has to identify appropriate observables which reflect the strength of the individual teams as close as possible. A criterion to distinguish different observables is presented. Surprisingly, chances for goals turn out to be much better suited than the goals themselves to characterize the strength of a team. Routes towards further improvement of the prediction are indicated. Finally, two specific applications are discussed. © 2014 Heuer, Rubner.

De Jong D.H.,Zernike Institute for Advanced Materials | De Jong D.H.,Institute of Physical Chemistry of Combustion | Liguori N.,VU University Amsterdam | Van Den Berg T.,Zernike Institute for Advanced Materials | And 3 more authors.
Journal of Physical Chemistry B | Year: 2015

Electron transfers within and between protein complexes are core processes of the electron transport chains occurring in thylakoid (chloroplast), mitochondrial, and bacterial membranes. These electron transfers involve a number of cofactors. Here we describe the derivation of molecular mechanics parameters for the cofactors associated with the function of the photosystem II core complex: plastoquinone, plastoquinol, heme b, chlorophyll A, pheophytin, and β-carotene. Parameters were also obtained for ubiquinol and ubiquinone, related cofactors involved in the respiratory chain. Parameters were derived at both atomistic and coarse grain (CG) resolutions, compatible with the building blocks of the GROMOS united-atom and Martini CG force fields, respectively. Structural and thermodynamic properties of the cofactors were compared to experimental values when available. The topologies were further tested in molecular dynamics simulations of the cofactors in their physiological environment, e.g., either in a lipid membrane environment or in complex with the heme binding protein bacterioferritin. © 2015 American Chemical Society.

Heuer A.,Institute of Physical Chemistry of Combustion | Rubner O.,Institute of Physical Chemistry of Combustion
PLoS ONE | Year: 2012

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified. © 2012 Heuer, Rubner.

Reuter A.,Monash Institute of Pharmaceutical Sciences | Reuter A.,Max Planck Graduate Center | Reuter A.,Institute of Physical Chemistry of Combustion | Panozza S.E.,University of Melbourne | And 15 more authors.
Journal of Immunology | Year: 2015

Ab-targeted vaccination involves targeting a receptor of choice expressed by dendritic cells (DCs) with Ag-coupled Abs. Currently, there is little consensus as to which criteria determine receptor selection to ensure superior Ag presentation and immunity. In this study, we investigated parameters of DC receptor internalization and determined how they impact Ag presentation outcomes. First, using mixed bone marrow chimeras, we established that Ag-targeted, but not nontargeted, DCs are responsible for Ag presentation in settings of Ab-targeted vaccination in vivo. Next, we analyzed parameters of DEC205 (CD205), Clec9A, CD11c, CD11b, and CD40 endocytosis and obtained quantitative measurements of internalization speed, surface turnover, and delivered Ag load. Exploiting these parameters in MHC class I (MHC I) and MHC class II (MHC II) Ag presentation assays, we showed that receptor expression level, proportion of surface turnover, or speed of receptor internalization did not impact MHC I or MHC II Ag presentation efficiency. Furthermore, the Ag load delivered to DCs did not correlate with the efficiency of MHC I or MHC II Ag presentation. In contrast, targeting Ag to CD8+ or CD82 DCs enhanced MHC I or MHC II Ag presentation, respectively. Therefore, receptor expression levels, speed of internalization, and/or the amount of Ag delivered can be excluded as major determinants that dictate Ag presentation efficiency in setting of Ab-targeted vaccination. Copyright © 2015 by The American Association of Immunologists, Inc.

Eshet H.,ETH Zurich | Khaliullin R.Z.,ETH Zurich | Kuhne T.D.,Institute of Physical Chemistry of Combustion | Kuhne T.D.,Johannes Gutenberg University Mainz | And 2 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

An interatomic potential for high-pressure high-temperature (HPHT) crystalline and liquid phases of sodium is created using a neural-network (NN) representation of the ab initio potential-energy surface. It is demonstrated that the NN potential provides an ab initio quality description of multiple properties of liquid sodium and bcc, fcc, and cI16 crystal phases in the P-T region up to 120 GPa and 1200 K. The unique combination of computational efficiency of the NN potential and its ability to reproduce quantitatively experimental properties of sodium in the wide P-T range enables molecular-dynamics simulations of physicochemical processes in HPHT sodium of unprecedented quality. © 2010 The American Physical Society.

Saha S.,Institute of Physical Chemistry of Combustion | Fischer K.,Institute of Physical Chemistry of Combustion | Muthukumar M.,Institute of Physical Chemistry of Combustion | Muthukumar M.,University of Massachusetts Amherst | Schmidt M.,Institute of Physical Chemistry of Combustion
Macromolecules | Year: 2013

The apparent molar mass of a partially quaternized poly-2-vinylpyridines (degree of quaternization 4.3% < Q < 35%) in 1-propanol is measured by light scattering at low ionic strength (10-6 M < cs < 10-3 M) as a function of polyion repeat unit concentration (7 × 10-5 monomol/L < cm,p < 4 × 10 -2 monomol/L). No dialysis was applied prior to measurements. The apparent molar mass under "salt-free" conditions is smaller than the true molar mass by an order of magnitude, while approaching the true value at higher ionic strength. Concomitant data on the dependence of scattering intensity on scattering wave vector show that the dilute polyelectrolyte solutions are strongly correlated. A recent theory by Muthukumar for light scattering of dilute polyelectrolyte solutions, developed for correlated multicomponent systems, accounts for interchain electrostatic correlations and regularization of polymer charge by counterion binding isotherm. The experimental results on the relation between the apparent and true molar masses as a function of salt concentration are compared with the predictions of Muthukumar's counterion adsorption theory. Taking binding equilibrium constant as a single fitting parameter, this theory is demonstrated to describe the experimental data as long as the chains do not interact significantly. © 2013 American Chemical Society.

Grasynski K.,Institute of Physical Chemistry of Combustion
PESC Record - IEEE Annual Power Electronics Specialists Conference | Year: 2015

For several years the German Ministry of Research and Technology (BMFT) sponsored investigations to realize large communication satellites, and to develop hardware of special critical components. The developments in the field of energy supply were a main effort. Power conditioning systems up to 10 kW are required. On principle it is possible to realize power conditioning for this large power range on the basis of DC-systems. But there rises problems relating to parts and weight closely associated with the thermal control system. To find a better solution several firms in Germany (AEG-Telefunken, Dornier System AG, Siemens AG and Teldix GmbH) investigated power conditioning concepts with AC distribution in the frequency range of about 20 kHz. First results indicated that even with an AC-system it is not possible to find a fundamental solution of the above mentioned problems, AC-systems seem to present certain advantages, though. In this paper some results of the developments of power conditioning concepts for a high power communication satellite are discussed. It is shown that an AC-system with regulated sinusoidal mainbus voltage is flexible and suited for high power applications. But for special applications decentralized current resonance systems may be better suited due to their high efficiency. © 1977 IEEE.

Hakobyan D.,Institute of Physical Chemistry of Combustion | Heuer A.,Institute of Physical Chemistry of Combustion
Journal of Physical Chemistry B | Year: 2013

Ternary mixtures of saturated and unsaturated phospholipids and cholesterol constitute a well-known model system to study raft formation in membranes. This phenomenon is, e.g., observed in cell membranes. Here, coarse-grained (CG) and microscopic united-atom (UA) simulations are performed to investigate the phase separation of a membrane bilayer for the ternary system of saturated 16:0 (DPPC) and unsaturated 18:2 (DUPC) phospholipids and cholesterol (CHOL). The results of a 9 μs UA simulation demonstrate the onset of phase separation and can be compared with properties of the corresponding CG system. While sharing the structural features of phase separation in the CG model, the onset of demixing for the UA model is 40 times slower. This factor can be rationalized by the different short-time diffusion constants. Various system properties such as order parameters and lipid-CHOL and CHOL-CHOL interactions are analyzed and compared between the UA and CG models. From the structural perspective, the phase separation process appears to be rather similar for both models, which illustrates once more the power of using CG approaches. © 2013 American Chemical Society.

Loading Institute of Physical Chemistry of Combustion collaborators
Loading Institute of Physical Chemistry of Combustion collaborators