In the framework of this project we propose the study of (α,γ) reactions relevant to the astrophysics p-process nucleosynthesis. Specifically, we are aiming to the experimental and theoretical investigation at astrophysical beam energies selected (α,γ) reactions, such as: 73Ge(α,γ)77Se and 102Pd(α,γ)106Cd. The goal of the study, is by using the 4π NaI(Tl) detector to provide experimental data in previously unexplored energy regions or in beam energies were the existing experimental information is insufficient for setting firm constrains of the theoretical model calculations. Accordingly, we suggest the study of the excitation function of the above mentioned reactions for α-beam energies between 6-15 MeV, as provided by Dynamitron Tandem Laboratorium (DTL) of the Ruhr-Universität Bochum and by adopting an energy step of the order of 0.5 MeV.

During the evolution of chloroplasts from a cyanobacterial endosymbiont, ancient prokaryotic protein targeting machineries were adapted and combined with novel targeting mechanisms to facilitate protein transport in chloroplasts. In the proposed project we aim to analyse the molecular details of post- and cotranslational thylakoid membrane protein transport mechanisms in the moss Physcomitrium patens. These data will reveal insight into the evolutionary driving forces that triggered drastic molecular adaptations during land plant evolution.

Persistent organic pollutants (POPs) are known to have adverse effects on human health and the environment. Thus, an effective risk assessment with concern on POP adsorption potential in the soil compartment is of high interest. The objective of our study was to develop a reliable, rapid and low-cost method which is able to predict the adsorption of two model POPs, 4-n-nonylphenol (NP) and perfluorooctanoic acid (PFOA), in soil samples based on spectral information (MIR) and partial least-square analyses (PLSR). For the model development 96 top- as well as subsoils were used. To characterize the composition of the samples, they were analyzed for particle size distribution, manganese and iron oxide concentration, organic carbon content (SOC), pH and the soil surface area. The KD-values for NP and PFOA were calculated in batch experiments.

This project is dedicated to thin film analysis of materials of interest deposited by the IMC group in a collaborative effort with partners from academia / industry. Primarily, selected metallic thin film samples will be subjected to ion beam and x-ray analysis to gain insights in the effect of deposition technique and parameter variation on thin film composition and functionally exploitable properties.

Within the framework of CO2BioFeed, an approach to the sustainable industrial production of base chemicals is to be developed. The aim of the project is to convert CO2 with olefins from renewable sources into valuable intermediates. The key is to use CO2 as an oxidant for the epoxidation of lower alkenes and as a carboxylating agent for insertion into the C-H bonds of lower alkenes, producing acrylic acid derivatives. In this project, silver catalysts supported on mixed oxides (Mo, V, Te, Ce, Zr) tailored for CO2 conversion will be characterized. The hazard potential of the samples is considered low. XPS analysis is a key to the comprehensive characterization of the catalysts and deriving structure-performance relationships.

The properties of transition metal nitrides (TM-N) strongly depend on their chemical composition (e.g. TM/N ratio) and density. Both, density and composition are affected by synthesis parameters (e.g. temperature, plasma properties). Transition metal nitrides were synthesized by magnetron sputtering using sets of different process parameters. Mechanical properties like Young’s modulus and hardness are determined by nano indentation and residual stress is evaluated by curvature method. The aim of the project is to identify relationships between synthesis parameters, composition and density and mechanical properties. The project is part of the collaborative research center SFB-TR 87.

This project aims a combining a Stimulated Emission Depletion (STED) and a Scanning Ion Conductance Microscope (SICM) to allow simultaneous, correlated recording of the cellular topography and a protein distribution in living cells with diffraction-unlimited resolution.

Funded by: DFG, DFG

14C-labelled substrates or nutrients and combinations will be added to the moist soil samples after a 7-day pre-incubation period. The incubation will be conducted in a CarbO2Bot® instrument which allows temperature control and records CO2 evolution from the samples through changes in electric conductivity in an alkaline solution. After certain time intervals, the solution is replaced by a fresh one and the evolved 14CO2 is determined in a scintillation counter (Perkin Elmer Tri-Carb 2800 TR). In this way, the substrate-borne CO2 can be differentiated from the SOC-borne CO2 and priming effects are calculated by subtracting the CO2 evolved from an unsupplemented control sample (Hamer and Marschner 2005). Enzyme activities will be determined in soil suspensions to which fluorogenic substrates (MUF, AMC) are added in a 96 well microplate assay as described by Marx et al.(2001).

Pyroxenes are common minerals in a wide range of magmatic rocks. Diffusion chronometry using major and trace element zoning in pyroxenes is being increasingly used in the last decade but this approach is hampered by the incomplete availability of diffusion data. New experimental and analytical developments for sample investigations on the nanoscale now allow the urgently needed diffusion data for diffusion chronometry to be precisely measured. In our novel experimental approach we will combine pulsed laser deposition for the preparation of thin-film diffusion couples and samples will be investigated using various analytical methods on the nm-scale. RBS will be used to measure the Fe diffusion profile. This research project is a sub-project of a research unit of the DFG (FOR2881).

Funded by: Deutsche Forschungsgemeinschaft

The project addresses the focused ion beam implantation of metal ions from the rare earth group into semiconductor nanostructures. In particular, we focus on the incorporation of erbium ions (Er3+) into gallium arsenide (GaAs). The optical transitions of the erbium should lead to an emission of electro-magnetic radiation at a wavelength of 1.54 µm. To better quantify the optical investigation of this emission, it is crucial to qualitatively and quantitatively verify the incorporation of the erbium into GaAs after implantation. For this purpose, highly sensitive analytical methods will be used at RUBION. Among other methods, elemental analyses will be carried out with the help of PIXE. Other research in this field has shown that the luminescence of erbium can be increased by additional implantation of further elements. For this purpose, oxygen is implanted over the surface of the GaAs:Er samples and the luminescence is then investigated.

Fabricating metal oxide based nanostructures for their application in gas phase sensors. The project covers precursor development and its evaluation for thin film deposition via thermal and plasma assisted atomic layer deposition

Although ITO (Indium Tin Oxide) is a widely used transparent conductive oxide, H diffusion in ITO has not been analysed in detail, yet. Especially for the application as a contact layer in photovoltaic devices, ITO layers have been and are used intensively. For most PV devices hydrogen plays a crucial role due to its influence of the passivation of silicon surfaces. Hence, the movement of H atoms in ITO layers is of importance for understanding the performance of PV devices. Therefore, we plan to implant hydrogen into ITO layers. Secondary Ion Mass Spectroscopy (SIMS) and effusion spectroscopy will be applied to investigate the diffusion of hydrogen in the films and evaluate the diffusion coefficient from the depth profile Arrhenius dependency. Parameters: * the hydrogen peak should be implanted into a depth of about 0.1 to 0.15µm in the 0.6µm thick ITO layers (ITO on c-Si substrate) * two implantations are necessary with 10E15 and 3E15/cm^2 Best regards, Maurice Nuys

In the department RUBION ion-beams, in the area of the industrial implantation, ion irradiations in the MeV range are carried out on behalf of customers in cooperation with our partner, the rubitec GmbH. There is a wide range of different ions available. The available energy and dose range depends on the respective species and the wafer size of our customers. The possibilities are determined by us depending on the application for each customer on request. In this field we are certified according to DIN EN ISO 9001: 2015 !

Molybdenum Compunds, MoS2 and Mo(2)C are promising new catalysts for electrochemical applications, e.g. water electrolysers. It is planned to study several aspects of hydrogen dynamics in these materials using neutron scattering (ILL Grenoble), electrochemical spectroscopy (WH Recklinghausen) and nuclear reaction analysis (present proposal): hydrogen sorption, fast hydrogen diffusion under reaction conditions, hydrogen modes and substrate phonons as well as ortho-para-conversion of hydrogen on cold catalyst surfaces. Model systems of bulk materials, pure powder samples and electrochemical electrodes will be used. The expected results of these studies are diffusion parameters (binding sites, pathways, activation energies), and key parameters of structure and dynamics of the active surface. Since hydrogen sorption and the motion of several hydrogen species are involved, hydrogen concentrations profiles are required for the full interpretation of the neutron scattering results.

Funded by: Institut Laue-Langevin, Doktorandenstipendium

Oligodendrocytes are responsible for myelination in the nervous system thereby enabling faster action potential propagation. Their progenitors (OPCs) migrate from the subventricular zone towards their target cells and are able to renew or repair myelin sheets. A disruption may lead to unmyelinated axons in the nervous system, which is a typical symptom of multiple sclerosis. Greater knowledge of the dynamics of the growth-cone-like structures on OPC might shed more light on the migration and movement mechanisms of OPCs. Using super-resolution microscopy techniques, the dynamics of the tips will be further investigated.

The work includes material development and structural Layering of perovskite for electroluminescence and laser applications. Different layer formation procedures such as pure liquid phase processes, pure vacuum deposition, as well as hybrid deposition processes are demonstrated. The work aims to study and optimize luminescence quantum efficiency and optical amplification and to understand the relationship between composition / structure and optical amplification. And then, selected materials are integrated into electroluminescent devices.

Advanced practical experiments at the accelerators for students from the Ruhr University Bochum and Paderborn University.

In the course of this project cell cultures will be obtained from postnatal rats. These cultures primarily composed of neurons and astrocytes will be treated with growth factors or other proteins and factors that are capable of modulating neuronal excitability. Our aim is to test the hypothesis that an increased excitability in neurons also leads to an upregulated expression of Na+/K+-ATPase. We use Tritium-labeled ouabain which selectively binds to the Na+/K+-ATPase to determine the density of this enzyme in the cell membrane.

In vitro transcription with radioactive labeling

PIXE technique is applied for the qualitative and quantitative analysis of major and trace elements in various kinds of samples, such as in minerals, glasses, alloys etc. The concentrations of elements from Si up to U can be determined in samples of different structures, i.e. in homogeneous thin or thick samples, as well as in layered ones. The sensitivity of PIXE can reach levels of the order of a few parts per million (ppm).

VO2 is of interest due to its Semiconductor-to-Metal phase transition. Elmental addition can modulate the transition properties of VO2. To systematically study the effect of elemental doping, V-M-O thin film libraries with continuous composition spread are fabricated by magnetron reactive co-sputtering. The concentration of dopant (M) will be determined by Rutherford backscattering spectrometry (RBS). In addition, it has been reported that the stoichiometry of VOx, e.g., the ratio of oxygen to the metals, can also influence the transition properties. To estimate the amount of oxygen, Nuclear reaction analysis (NRA) will be performed on the libraries.

Funded by: DFG, DFG

This project supports the other ongoing RUBION-projects of RUB's IMC group. Complementary to the RBS/NRA project, selected thin films are subjected to XPS and AES analysis to gain insights into their surface chemical composition.