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A magnetic thermostat employing soft-ferromagnetic particles and a varying magnetic field has been developed to investigate a homogeneous granular gas system in microgravity. While the thermostat’s mechanism of creating homogeneous distribution of the particles was shown earlier, its characteristics have not been understood well due to limited access to a microgravity environment. Therefore, a parametric study by numerical simulation based on the discrete element method is carried out in this paper to evaluate effects of tunable parameters in the thermostat. The result shows the capability of the system and provides a wide range of options and improvements for future experiments. Moreover, it predicts that the thermostat allows variation of homogeneity and excitation level of the granular gas just by changing the magnetic parameters without using any mechanical means. In addition, the suggested improvement is experimentally implemented and evaluated in a drop tower test.

A compact fully protected microfocus X-radiography facility (XRISE-M) is presented for the study of microstructure evolution during the solidification of thin liquid alloy samples and chemical diffusion in liquid binary alloys in situ and in real-time aboard a sounding rocket. XRISE-M presently enables the simultaneous processing of either two near-isothermal solidification furnaces or a combination of a linear-shear cell diffusion furnace and a near-isothermal solidification furnace. For optimal detector calibration shortly before flight, the furnaces can be rotated around the central beam axis and calibration images can be recorded. The facility allows preheating the samples into the liquid state prior to lift-off without leakage during the ascent phase at accelerations of up to 27 g. Macrosegregation on remelting of thin metal samples for microstructure evolution investigations is prevented by an inclinable furnace metric. The use of ion-getter pumps for vacuum generation enables us to exploit the entire available time of reduced gravity for image recording and data acquisition. With the device and currently available sample environments, microstructure formation upon solidification and chemical diffusion under purely diffusive conditions in alloys can be investigated. The facility can be used equally for other investigations such as granular matter dynamics or metal foaming, provided that suitable experiment inserts are developed in the future.

Novel material thin-film solar cells are promising alternatives to conventional solar cells for future space applications. Previous terrestrial investigations have shown promising stability under simulated space conditions, pioneering the next step to test these solar cells under space conditions. Here, we present the sounding rocket experiment OHSCIS to characterize the electronic behavior of Organic and Hybrid Solar Cells In Space (OHSCIS). The mechanical and electronic design aims at maximizing the rate of data collection and the fail-safety for high scientific output with precise measurements. The maiden flight onboard the MAPHEUS-8 proved the experimental concept to be successful and produced valuable results for the operation and behavior of perovskite and organic solar cells in space.

The reactive interface between phthalocyanine (2HPc) and a Cu(111) surface was investigated with X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption/reaction (TPD/TPR). 2HPc reacts with Cu(111) to form copper(II) phthalocyanine (CuPc). For 2HPc submonolayers, the reaction starts already below 240 K. Thin 2HPc multilayers (4 monolayers) are completely converted into CuPc at elevated temperatures (500 K). To understand how molecules can react even though they are initially not in contact with the Cu surface, TPD/TPR studies with a NiPc interlayer between Cu and 2HPc were performed. These studies reveal the operation of an exchange mechanism, by which CuPc or NiPc molecules from the first layer are replaced by 2HPc molecules from higher layers. Once a 2HPc molecule comes into contact with the Cu surface, the molecule can react with the surface, forming CuPc, which can then be replaced by another unreacted 2HPc molecule. These findings have important implications for metal–organic int...

The interface formation upon vapor deposition of a metal onto a molecular organic semiconductor was studied using a well-defined complexation reaction between a metal and a porphyrin. Specifically, metallic cobalt (Co) was vapor deposited onto a thin film of 2H-tetraphenylporphyrin (2HTPP) at room temperature. The resulting interface was probed with Hard X-ray Photoelectron Spectroscopy (HAXPES) using photon energies between 2 and 6 keV to obtain a detailed depth profile of the chemical composition. Characteristic changes in the N 1s core level signals reveal the formation of a cobalt tetraphenylporphyrin (CoTPP) layer between the Co and 2HTPP layers. Assuming an abrupt interface between CoTPP and 2HTPP (layer-by-layer model), analysis of the XPS data results in a thickness of the CoTPP reaction layer of 1.6 nm. However, a more advanced numerical analysis allowed us to reconstruct details of the actual depth distribution of the CoTPP interphase layer: up to a depth of 1.5 nm, all 2HTPP molecules were converted into CoTPP. Beyond this depth, the CoTPP concentration decreases sharply within 0.15 nm to zero.

A Li4Ti5O12 (LTO) film was coated as buffer layer onto a LiNi0.5Mn1.5O4 (LNMO) high-voltage cathode, and after cycling of the cathode in a battery electrolyte, the LTO film was investigated by means of synchrotron radiation based hard X-ray photoelectron spectroscopy (HAXPES). By tuning the photon energy between 2 keV and 6 keV, we obtained non-destructive depth profiles of the coating material with probing depths ranging from 6 nm to 20 nm. The coating was found to be covered by a few nanometers thin surface layer resulting from electrolyte decomposition. This layer consisted predominantly of organic polymers as well as metal fluorides and fluorophosphates. A positive influence of the Li4Ti5O12 coating with regard to the size and stability of the surface layer was found. The coating itself consisted of a uniform mixture of Li(I), Ti(IV), Ni(II) and Mn(IV) oxides that most likely adopted a spinel structure by forming a solid solution of the two spinels LiNi0.5Mn1.5O4 and Li4Ti5O12 with Li, Mn, Ni and Ti cations mixing on the spinel octahedral sites. The diffusion of Ni and Mn ions into the Li4Ti5O12 lattice occurred during the heat treatment when preparing the cathode. The doping of Li4Ti5O12 with the open d-shell ions Ni(2+) (d(8)) and Mn(4+) (d(3)) should increase the electronic conductivity of the coating significantly, as was found in previous studies. The complex signal structure of the Ti 2p, Ni 2p and Mn 2p core levels provides insight into the chemical nature of the transition metal ions.

Ground based experiments, conducted in advanced space environment simulation facilities, complement the exo/astrobiological experiments in Low Earth Orbit (LEO). For example, the in-orbit ESA-facility EXPOSE on the International Space Station ISS can only accommodate a limited number of experiments for exposure to the space parameters high vacuum, intense radiation of galactic and solar origin and microgravity. Ground based experiments in carefully equipped and monitored simulation facilities allow necessary experiment preparation and additional investigation of a much wider variety of samples. In the ESA accepted experiment SSIOUX, ESA-RA-LS-01-PREP, an international consortium of 14 prime investigators will expose organic compounds and a wide range of microorganisms, from bacterial spores to complex microbial communities, to simulated space environment parameters in pursuit of exobiological questions on their resistance to space environment and the origin and distribution of life. The experiments will be conducted in the Planetary and Space Simulation Facilities of the Institute of Aerospace Medicine at DLR in Koln, Germany, where the simulated space parameters vacuum with controlled residual composition, ionizing radiation, polychromatic UV radiation and selected UV ranges from vacuum-UV to UVA, VIS and IR or individual monochromatic UV wavelengths, and temperature control at the sample site are provided individually or in selected combinations in 9 facilities of varying sizes. Parameters are constantly measured and data are available in real time online during the exposure. Experiments in these facilities discriminate between the effects of individual space parameters and selected combinations. In addition, they serve as ground experiments defining interesting and suitable biological samples for future space experiments and compliment the data of executed space experiments and those in progress. As 1 × g controls, they also enable the identification of microgravity effects when compared to the space experiments. Here, the SSIOUX consortium and their experiments will be presented as well as the ground based Planetary and Space Simulation Facilities at DLR. The results of the SSIOUX experiments will be directly comparable and are designed to lead to further understanding of adaptation and evolution of life.

Pyroelectric infrared sensor arrays are imaging devices for infrared radiation that utilize the temperature dependence of the remanent in polarization in pyroelectric materials. We use the finite element method for the calculation of the coupled thermo-electro-mechanical fields for an instance of a linear sensor array, derive the modulation transfer function from the simulation data, and compare the result to an analytical solution.

Dodecahydro-N-ethylcarbazole (H12-NEC) has been proposed as a potential liquid organic hydrogen carrier (LOHC) for chemical energy storage, as it combines both favourable physicochemical and thermodynamic properties. The design of optimised dehydrogenation catalysts for LOHC technology requires a detailed understanding of the reaction pathways and the microkinetics. Here, we investigate the dehydrogenation mechanism of H12-NEC on Pd(111) by using a surface-science approach under ultrahigh vacuum conditions. By combining infrared reflection-absorption spectroscopy, density functional theory calculations and X-ray photoelectron spectroscopy, surface intermediates and their stability are identified. We show that H12-NEC adsorbs molecularly up to 173 K. Above this temperature (223 K), activation of C-H bonds is observed within the five-membered ring. Rapid dehydrogenation occurs to octahydro-N-ethylcarbazole (H8-NEC), which is identified as a stable surface intermediate at 223 K. Above 273 K, further dehydrogenation of H8-NEC proceeds within the six-membered rings. Starting from clean Pd(111), C-N bond scission, an undesired side reaction, is observed above 350 K. By complementing surface spectroscopy, we present a temperature-programmed molecular beam experiment, which permits direct observation of dehydrogenation products in the gas phase during continuous dosing of the LOHC. We identify H8-NEC as the main product desorbing from Pd(111). The onset temperature for H8-NEC desorption is 330 K, the maximum reaction rate is reached around 550 K. The fact that preferential desorption of H8-NEC is observed even above the temperature threshold for H8-NEC dehydrogenation on the clean surface is attributed to the presence of surface dehydrogenation and decomposition products during continuous reactant exposure.

The focus of this chapter is single-crystal adsorption calorimetry, which is used for the direct measurement of adsorption energies on well-defined surfaces, both single- and poly-crystalline. The method was pioneered in the 1990s mainly by D.A. King and C.T. Campbell and is based on earlier work by S. Cerny. Especially in recent years, the technique has seen increasing proliferation and development. In contrast to desorption-based methods, such as temperature-programmed desorption and isosteric measurements, calorimetry is also well suited for irreversible reactions. The systems studied range from simple adsorption of small molecules, such as CO and NO, to surface reconstructions, reaction intermediates, hydroxyl group formation, metal adsorption and diffusion into polymers, particle-size dependent adsorption energies on model catalysts and even electrochemical reactions on electrode surfaces in the liquid phase.

In diesem Kapitel werden anhand der Anwendungen des betrieblichen Informationsmanagements die verschiedenen Wissens- und Informationsprozesse dargestellt, die bei der Entwicklung semantischer Anwendungen grundlegend sind. Ziel ist es aus der Entwicklungsperspektive der einzelnen Anwendungen die Notwendigkeit und den Nutzen aufzuzeigen, der sich aus dem Einsatz von semantischen Technologien ergibt. Die vorgestellten Fallbeispiele veranschaulichen die Einsatzgebiete von semantischen Technologien in der betrieblichen Anwendung.

A formula that can analyze the laser Doppler velocimeter spectrum was derived. The formula showed good agreement with computational experimental results. The use of a Fourier transform lens as detection optics was proposed and was found to be independent of the displacement of the object along the direction parallel to the optical axis. An experimental method was also proposed that can make the simultaneous measurement of velocity and displacement possible simply by adding a second detector. By using two detectors, not only can displacement of the surface be measured, but also the results of the speed measurement can be compensated for.