Planung flexibler Produktionskapazitäten im Spannungsfeld logistischer und monetärer Ziele

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Monitoring Bioeconomy Transitions with Economic−Environmental and Innovation Indicators: Addressing Data Gaps in the Short Term

Monitoring bioeconomy transitions and their effects can be considered a Herculean task, as they cannot be easily captured using current economic statistics. Distinctions are rarely made between bio-based and non-bio-based products when official data is collected. However, production along bioeconomy supply chains and its implications for sustainability require measurement and assessment to enable considered policymaking. We propose a starting point for monitoring bioeconomy transitions by suggesting an adapted framework, relevant sectors, and indicators that can be observed with existing information and data from many alternative sources, assuming that official data collection methods will not be modified soon. Economic–environmental indicators and innovation indicators are derived for the German surfactant industry based on the premise that combined economic–environmental indicators can show actual developments and trade-offs, while innovation indicators can reveal whether a bioeconomy transition is likely in a sector. Methodological challenges are discussed and low-cost; high-benefit options for further data collection are recommended.Peer Reviewe

Towards analyzing the influence of measurement errors in magnetic resonance imaging of fluid flows : development of an interval-based iteration approach

Magnetic Resonance Imaging (MRI) provides an insight into opaque structures and does not only have a large number of applications in the field of medical examinations but also in the field of engineering. In technical applications, MRI enables a contactless measurement of the two- or threedimensional velocity field within minutes. However, various measurement methods would benefit from an acceleration of the measurement procedure. Compressed Sensing is a promising method to fit this need. A random undersampling of the sampled data points enables a significant reduction of acquisition time. As this method requires a nonlinear iterative reconstruction of unmeasured data to obtain the same data quality as for a conventional fully sampled measurement, it is essential to estimate the influence of uncertainty on the quantitative result. This paper investigates the implementation of interval arithmetic approaches with a focus on the applicability in the frame of compressed sensing techniques. These approaches are able to handle bounded uncertainty not only in the case of linear relationships between measured data and the computed outputs but also allow for solving the necessary optimality criteria for the fluid velocity reconstruction in an iterative manner under the assumption of set-valued measurement errors and bounded representations of noise

Chiral photoelectron angular distributions from ionization of achiral atomic and molecular species

We show that the combination of two achiral components - atomic or molecular target plus a circularly polarized photon - can yield chirally structured photoelectron angular distributions. For photoionization of CO, the angular distribution of carbon K-shell photoelectrons is chiral when the molecular axis is neither perpendicular nor (anti-)parallel to the light propagation axis. In photo-double-ionization of He, the distribution of one electron is chiral, if the other electron is oriented like the molecular axis in the former case and if the electrons are distinguishable by their energy. In both scenarios, the circularly polarized photon defines a plane with a sense of rotation and an additional axis is defined by the CO molecule or one electron. This is sufficient to establish an unambiguous coordinate frame of well-defined handedness. To produce a chirally structured electron angular distribution, such a coordinate frame is necessary, but not sufficient. We show that additional electron-electron interaction or scattering processes are needed to create the chiral angular distribution

Kinematically complete experimental study of Compton scattering at helium atoms near the ionization threshold

Compton scattering is one of the fundamental interaction processes of light with matter. Already upon its discovery [1] it was described as a billiard-type collision of a photon kicking a quasi-free electron. With decreasing photon energy, the maximum possible momentum transfer becomes so small that the corresponding energy falls below the binding energy of the electron. Then ionization by Compton scattering becomes an intriguing quantum phenomenon. Here we report a kinematically complete experiment on Compton scattering at helium atoms below that threshold. We determine the momentum correlations of the electron, the recoiling ion, and the scattered photon in a coincidence experiment finding that electrons are not only emitted in the direction of the momentum transfer, but that there is a second peak of ejection to the backward direction. This finding links Compton scattering to processes as ionization by ultrashort optical pulses [2], electron impact ionization [3,4], ion impact ionization [5,6], and neutron scattering [7] where similar momentum patterns occur.Comment: 7 pages, 4 figure

Angular dependence of the Wigner time delay upon tunnel ionization of H2H_{2}

More than 100 years after its discovery and its explanation in the energy domain, the duration of the photoelectric effect is still heavily studied. The emission time of a photoelectron can be quantified by the Wigner time delay. Experiments addressing this time delay for single-photon ionization became feasible during the last 10 years. A missing piece, which has not been studied, so far, is the Wigner time delay for strong-field ionization of molecules. Here we show experimental data on the Wigner time delay for tunnel ionization of $H_{2}$ molecules and demonstrate its dependence on the emission direction of the electron with respect to the molecular axis. We find, that the observed changes in the Wigner time delay can be quantitatively explained by elongated/shortened travel paths of the electrons that are due to spatial shifts of the electron's birth position after tunneling. This introduces an intuitive perspective towards the Wigner time delay in strong-field ionization.Comment: 17 pages, 6 figure

Effect of quantum confinement on exciton-phonon interactions

We investigate the homogeneous linewidth of localized type-I excitons in type-II GaAs/AlAs superlattices. These localizing centers represent the intermediate case between quasi-two-dimensional (Q2D) and quasi-zero-dimensional localizations. The temperature dependence of the homogeneous linewidth is obtained with high precision from micro-photoluminescence spectra. We confirm the reduced interaction of the excitons with their environment with decreasing dimensionality except for the coupling to LO-phonons. The low-temperature limit for the linewidth of these localized excitons is five times smaller than that of Q2D excitons. The coefficient of exciton-acoustic-phonon interaction is 5 ~ 6 times smaller than that of Q2D excitons. An enhancement of the average exciton-LO-phonon interaction by localization is found in our sample. But this interaction is very sensitive to the detailed structure of the localizing centers.Comment: 6 pages, 4 figure

Observation of Photoion Backward Emission in Photoionization of He and N2

We experimentally investigate the effects of the linear photon momentum on the momentum distributions of photoions and photoelectrons generated in one-photon ionization in an energy range of 300 eV $\leq~E_\gamma~\leq$ 40 keV. Our results show that for each ionization event the photon momentum is imparted onto the photoion, which is essentially the system's center of mass. Nevertheless, the mean value of the ion momentum distribution along the light propagation direction is backward-directed by $-3/5$ times the photon momentum. These results experimentally confirm a 90 year old prediction.Comment: 5 pages, 3 figure

Dental therapy before and after radiotherapy–an evaluation on patients with head and neck malignancies

The present investigation evaluates the dental care situation of patients with head and neck cancer before and after radiotherapy. The situations of these patients in 1993 and 2005 were compared to detect similarities, differences and developments. In the years 1993 and 2005, 37 and 36 patients, respectively, with head and neck cancer treated by the local departments of otorhinolaryngology and of radiotherapy were examined consecutively according to their aftercare appointments. Time points of radiotherapy treatment of the patients evaluated in 1993 varied from 1984 to 1993. The patients evaluated in 2005 had received radiotherapy between 1998 and 2005. Therefore the applied radiotherapeutic regimen differed not only between the two groups of patients, but also within each group. The information for these investigations was provided anonymously. It was evaluated with descriptive statistics. The evaluation of the data shows distinct differences with respect to preventive and therapeutic dental care measures. In 2005, 35 out of 36 patients (97.2%) had a dental consultation before radiotherapy (1993, 65%). All 27 dentate patients (100%) obtained a splint for fluoride application (1993, none). 29% fewer edentulous patients were seen than in 1993. The number of teeth destroyed decreased from 19.2% (1993) to 7.8% in 2005. Mycoses due to Candida spp. and chronic failures in wound healing were rare (5.5%). In the course of the 12 years, prophylactic measures, such as the application of splints for fluoride treatment, were intensified. However, concepts for the dental care of patients undergoing radiotherapy, especially following the radiation, should be widened to avoid ruined teeth and long delayed wound healings