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Many physical properties of oxides can be changed by inducing lattice distortions in the crystal through heteroepitaxial growth of thin films. The average lattice strain can often be tuned by changing the film thickness or using suitable buffer layers between film and substrate. The exploitation of the full potential of strain engineering for sample or device fabrication rests on the understanding of the fundamental mechanisms of stress generation and evolution. For this study an optical measurement of the substrate curvature is used to monitor in situ how the stress builds up and relaxes during the growth of oxide thin films by pulsed laser deposition. The relaxation behavior is correlated with the growth mode, which is monitored simultaneously with reflection high-energy electron diffraction. The stress relaxation data is fitted and compared with theoretical models for stress evolution which were established for semiconductor epitaxy. The initial stage of the growth appears to be governed by surface stress and surface energy effects, while the subsequent stress relaxation is found to be fundamentally different between films grown on single-crystal substrates and on buffer layers. The first case can be rationalized with established theoretical models, but these models fail in the attempt to describe the growth on buffer layers. This is most probably due to the larger average density of crystalline defects in the buffer layers, which leads to a two-step stress relaxation mechanism, driven first by the nucleation and later by the migration of dislocation lines.

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3D-Polarized Light Imaging has become a unique technique to study the fiber architecture of unstained brain sections at the meso- and microscale. It exploits the intrinsic birefringence of nerve fibers which is measured with a customized Polarimeter in which the brain section is placed on a tiltable specimen stage. So far, a computationally fast analytical method based on the discrete Fourier transformation to analyze the data acquired with the tiltable specimen stage has been used. In this study, we propose a new algorithm based on a fitting approach which provides an improved stability against measurement noise resulting in a more realistic orientation interpretation, in particular for low signals. For the first time, it is demonstrated how fiber courses at the boundary of white and grey matter can robustly be reconstructed with 3D-PLI. This significantly improves the reliability of mapping the cortex based on 3D-PLI data.

Julich Supercomputing Centre (JSC) started running (extreme) scaling workshops with its first IBM Blue Gene supercomputer, finally spanning three generations each seeing an increase in the number of cores and available threads. Over the years, this workshop series attracted numerous international code teams and resulted in many applications capable of running on all available cores of each system. This article reviews some of the knowledge gained with running and tuning highly-scalable applications, focussing on JUQUEEN, the IBM Blue Gene/Q at JSC. The ability to execute successfully on all 458752 cores with up to 1.8 million processes or threads may qualify codes for the High-Q Club, which serves as a showcase for diverse codes scaling to the entire 28 racks, effectively defining a collection of the highest scaling codes on JUQUEEN. The intention was to encourage other developers to invest in tuning and scaling their codes while identifying the necessary key aspects for that goal. As this era closes, it is timely to compare the characteristics of the 32 High-Q Club member codes, considering their strong and/or weak scaling, exploitation of hardware threading, and whether/how intra-node multi-threading is employed combined with message-passing. We also identify the obstacles for scaling such as inefficient use of limited compute node memory and file I/O as key governing factors. Overall, the analysis provides guidance as to how applications may (need to) be designed in future to exploit expected exa-scale computer systems.

We use resonant and non-resonant X-ray diffraction measurements in combination with first-principles electronic structure calculations and Monte Carlo simulations to study the relationship between crystal structure and multiferroic orders in the orthorhombic perovskite manganites, o-$R$MnO$_3$ ($R$ is a rare-earth cation or Y). In particular, we focus on how the internal lattice parameters (Mn-O bond lengths and Mn-O-Mn bond angles) evolve under chemical pressure and epitaxial strain, and the effect of these structural variations on the microscopic exchange interactions and long-range magnetic order. We show that chemical pressure and epitaxial strain are accommodated differently by the crystal lattice of o-$R$MnO$_3$, which is key for understanding the difference in magnetic properties between bulk samples and strained films. Finally, we discuss the effects of these differences in the magnetism on the electric polarization in o-$R$MnO$_3$., Comment: 16 pages, 10 figures

This chapter discusses recent progress in 2D and 3D printing technologies, in particular laser-induced forward transfer and two-photon polymerization (TPP). We explore their potential for applications in micro-electronics, protein microarrays, sensors and biosensors, and tissue engineering. An overview of the factors that affect patterning, miniaturization and functionality is presented. A special focus is placed on laser direct writing via TPP for the fabrication of 3D vertical microtubes acting as microreservoirs for an osteogenic drug.

The micro-laser plasma thruster (μ-LPT) is a device aimed at orienting and repositioning small satellites above the atmosphere. These devices are based on IR diode lasers utilized for the ablation of polymers and production of thrust for the control of the satellite motion. In this work, different polymer systems, i.e., poly(vinyl chloride) (PVC), glycidyl azide polymer (GAP), and poly(vinyl nitrate) (PVN) with two absorbers, i.e., carbon nanoparticles (C) and an IR-dye (IR), have been investigated for an application in μ-LPT. The properties of a plasma produced by the irradiation of GAP + C, GAP + IR, PVC + C, and PVN + C with 100 fs laser pulses has been investigated by time-resolved plasma imaging and time and space resolved plasma emission spectroscopy.

In order to improve the understanding of laser interactions of materials with homogeneous nano-structures, pulsed laser induced plasma from a low density, high-porosity multiwall carbon nanotube (CNT) sponge and a dense graphite block have been investigated by combinational spectroscopy approaches. We observe distinct differences in the laser-induced light emission of the CNT sponge and graphite block which we attribute to the occurrence of a phase explosion caused by the lower thermal conductivity and weaker mechanical strength of the CNT sponge. Furthermore, spectroscopy plasma analysis reveals that differences in the surface of the two systems play a key role in the generation of negative carbon ions. We observe a more effective production of negative ions for the CNT sponge as compared to the graphite block due to the greater number of surface defects of the CNT sponge.

Summary Homogeneous cluster architectures, which used to dominate high-performance computing (HPC), are challenged today by heterogeneous approaches utilizing accelerator or co-processor devices. The DEEP (Dynamical Exascale Entry Platform) project is implementing a novel architecture for HPC, in which a standard HPC cluster is directly connected to a so-called ‘Booster’: a cluster of many-core processors. By these means heterogeneity is organized differently as in today's standard approach, where accelerators are added to each node of the cluster. In order to adapt application codes to this Cluster-Booster architecture as seamless as possible, DEEP has developed a complete programming environment. It integrates the offloading functionality given by the Message Passing Interface standard with an abstraction layer based on the task-based OmpSs programming paradigm. This paper presents the DEEP project with an emphasis on the DEEP programming environment. Copyright © 2015 John Wiley & Sons, Ltd.

The crystallization kinetics of amorphous 3 and 8 mol% yttria stabilized zirconia (3YSZ and 8YSZ) thin films grown by pulsed laser deposition (PLD), spray pyrolysis and dc-magnetron sputtering are explored. The deposited films were heat treated up to 1000 °C ex situ and in situ in an X-ray diffractometer. A minimum temperature of 275 °C was determined at which as-deposited amorphous PLD grown 3YSZ films fully crystallize within five hours. Above 325 °C these films transform nearly instantaneously with a high degree of micro-strain when crystallized below 500 °C. In these films the t′′ phase crystallizes which transforms at T > 600 °C to the t′ phase upon relaxation of the micro-strain. Furthermore, the crystallization of 8YSZ thin films grown by PLD, spray pyrolysis and dc-sputtering are characterized by in situ XRD measurements. At a constant heating rate of 2.4 K min−1 crystallization is accomplished after reaching 800 °C, while PLD grown thin films were completely crystallized already at ca. 300 °C.

With the IBM Blue Gene/P supercomputer JUGENE, inaugurated in May 2009 at the Julich Supercomputing Centre (JSC), the Forschungszentrum Julich has entered the era of petaflop supercomputer performance in Europe. The Julich Supercomputing Centre (JSC), as a part of the Institute for Advanced Simulation within the Forschungszentrum Julich, operates supercomputers of the highest performance class in Europe. When IBM Blue Gene technology became available in 2004/2005, Forschungszentrum Julich recognized the potential of this architecture as a leadership-class system for capability computing applications. The lifetime of the largest Blue Gene/P in the world ended in mid 2012 after having been in operation for over three years and being superseded by an IBM Blue Gene/Q system. Blue Gene/P is an MPP type system with the design goal of achieving an optimal Performance/Watt ratio and extreme scalability. The JUGENE system in Julich consists of 72 Blue Gene/P racks, configured as 9 rows with 8 racks each, which sums up to 73,728 nodes.

The introduction of manganite buffer layers, La7/8Sr1/8MnO3 (LSMO) in particular, at the metallic interface between SrTiO3 (STO) and another band insulator suppresses the carrier density of the interfacial two-dimensional electron gas (2DEG) and improves significantly the electron mobility. However, the mechanisms underlying the extreme mobility enhancement remain elusive. Herein, we used 18O isotope exchanged SrTi18O3 as substrates to create 2DEG at room temperature with and without the LSMO buffer layer. By mapping the oxygen profile across the interface between STO18 and disordered LaAlO3 or yttria-stabilized zirconia (YSZ), we provide unambiguous evidence that redox reactions occur at oxide interfaces even grown at room temperature. Moreover, the manganite buffer layer not only suppresses the carrier density but also strongly suppresses the oxygen exchange dynamics of the STO substrate, which likely prevents the reduction of STO during the formation of the 2DEG. The underlying mechanism on the enhanced electron mobility at buffered oxide interfaces is also discussed., to be apprear in PRMater, 2017

The generation of cavitation fields for the pre-treatment of anaerobic sludge was studied by means of a novel acoustic measuring system. The influence of different reactor dimensions (i.e., choosing reaction chamber widths of 40, 60 and 80 mm) on the cavitation intensity was determined at various solid contents, flow rates and static pressures. Results suggest that the cavitation intensity is significantly reduced by the sonication of liquids with a high solid content. By increasing the pressure to 1 bar, the intensity of bubble implosions can be enhanced and the sound attenuation in the solid fraction is partly compensated compared to ambient pressure. However, a further increase in pressure to 2 bars has a detrimental effect due to the suppression of powerful bubbles. A reduction of the reactor gap permits an intensification of the treatment of waste activated sludge (WAS) by concentrating the ultrasound power from 6 to 18 dB. This effect is less relevant in digested sludge (DS) with its markedly lower total solids content (2.2% vs. 6.9% of solids in WAS). Increasing the flow rate, resulting in a flow velocity of up to 7 m/min, has no influence on the cavitation intensity. By adapting the reactor design and the static pressure to the substrate characteristics, the intensity of the sonication can be notably improved. This allows the design of sonication devices that are suitable for the intensive treatment of wastewater sludge.

The impact of the inoculum's origin on the methane yield in Biochemical Methane Potential (BMP) tests was investigated. The three most commonly applied inocula were chosen, originating from (i) a digester of a wastewater treatment plant, (ii) an agricultural biogas plant treating manure and energy crops, and (iii) a biowaste treatment plant. The performance of each inoculum was tested with four different substrates, namely sewage sludge, dried whole crop maize, food waste, and microcrystalline cellulose as a typical reference material. The results revealed that the choice of inoculum had no significant impact on the specific methane yield of the tested substrates except for cellulose. Still, the specific methane production rate was significantly influenced by the choice of the inoculum especially for sewage sludge, but also for food waste and cellulose, whereas it became clear that an inoculum adapted to a substrate is beneficial for a speedy digestion.

We present a calculation of the leptonic decay-constant ratio $f_K/f_\pi$ in 2+1 flavor QCD, performed via a series of lattice studies, which allows us to quantify all sources of systematic uncertainty. Our final result is $f_K/f_\pi=1.182(28)$, and with isospin breaking corrections from ChPT the charged decay-constant ratio reads $f_{K^\pm}/f_{\pi^\pm}=1.178(28)$. With $V_\mathrm{ud}$ from super-allowed nuclear beta decays, the CKM matrix element $V_\mathrm{us}=0.2282(54)$ is perfectly compatible with the first-row unitarity constraint of the Standard Model.

Solid oxide oxygen ion and proton conductors are a highly important class of materials for renewable energy conversion devices like solid oxide fuel cells. Ba2In2O5 (BIO) exhibits both oxygen ion and proton conduction, in a dry and humid environment, respectively. In a dry environment, the brownmillerite crystal structure of BIO exhibits an ordered oxygen ion sublattice, which has been speculated to result in anisotropic oxygen ion conduction. The hydrated structure of BIO, however, resembles a perovskite and the protons in it were predicted to be ordered in layers. To complement the significant theoretical and experimental efforts recently reported on the potentially anisotropic conductive properties in BIO, we measure here both the proton and oxygen ion conductivity along different crystallographic directions. Using epitaxial thin films with different crystallographic orientations, the charge transport for both charge carriers is shown to be anisotropic. The anisotropy of the oxygen ion conduction can indeed be explained by the layered structure of the oxygen sublattice of BIO. The anisotropic proton conduction, however, further supports the suggested ordering of the protonic defects in the material. The differences in proton conduction along different crystallographic directions attributed to proton ordering in BIO are of a similar extent as those observed along different crystallographic directions in materials where proton ordering is not present but where protons find preferential conduction pathways through chainlike or layered structures.

Controlling material properties by modulating the crystalline structure has been attempted using various techniques, e.g., hydrostatic pressure, chemical pressure, and epitaxy. These techniques succeed to improve properties and achieve desired functionalities by changing the unit cell in all dimensions. In order to obtain a more detailed understanding on the relation between the crystal lattice and material properties, it is desirable to investigate the influence of a smaller number of parameters. Here, we utilize the combination of chemical pressure and epitaxy to modify a single lattice parameter of the multiferroic orthorhombic $R\mathrm{Mn}{\mathrm{O}}_{3}$ ($R=\mathrm{rare}\text{\ensuremath{-}}\mathrm{earth}$; $\mathrm{o}\text{\ensuremath{-}}R\mathrm{Mn}{\mathrm{O}}_{3}$) system. By growing a series of $\mathrm{o}\text{\ensuremath{-}}R\mathrm{Mn}{\mathrm{O}}_{3}$ ($R=\mathrm{Gd}--\mathrm{Lu}$) films coherently on (010)-oriented $\mathrm{YAl}{\mathrm{O}}_{3}$ substrates, the influence of chemical pressure is reflected only along the $b$ axis. Thus a series of $\mathrm{o}\text{\ensuremath{-}}R\mathrm{Mn}{\mathrm{O}}_{3}$ with $a\ensuremath{\sim}5.18\phantom{\rule{0.16em}{0ex}}\AA{},\phantom{\rule{0.16em}{0ex}}5.77\phantom{\rule{0.16em}{0ex}}\AA{}lbl5.98\phantom{\rule{0.16em}{0ex}}\AA{}$, and $c\ensuremath{\sim}7.37\phantom{\rule{0.16em}{0ex}}\AA{}$ were obtained. Raman spectra analysis reveals that the change of the $b$-axis parameter induces a shift of the oxygen in the nominally ``fixed'' $ca$ plane. Their ferroelectric ground state is independent on the $b$-axis parameter showing polarization of $\ensuremath{\sim}1\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{C}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}2}$ along the $a$ axis for the above-mentioned range, except for $b\ensuremath{\sim}5.94\phantom{\rule{0.16em}{0ex}}\AA{}$, which corresponds to $\mathrm{TbMn}{\mathrm{O}}_{3}$ showing $\ensuremath{\sim}2\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{C}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}2}$. This result implies that multiferroic order of $\mathrm{o}\text{\ensuremath{-}}R\mathrm{Mn}{\mathrm{O}}_{3}$ is almost robust against the $b$-axis parameter provided that the dimension of the $ca$ plane is fixed to $7.37\phantom{\rule{0.16em}{0ex}}\AA{}\ifmmode\times\else\texttimes\fi{}5.18\phantom{\rule{0.16em}{0ex}}\AA{}$.

The size of the band gap and the energy position of the band edges make several oxynitride semiconductors promising candidates for efficient hydrogen and oxygen production under solar light illumination. The intense research efforts dedicated to oxynitride materials have unveiled the majority of their most important properties. However, two crucial aspects have received much less attention. One is the critical issue of the compositional/structural surface modifications occurring during operation and how these affect the photoelectrochemical performance. The second concerns the relation between the electrochemical response and the crystallographic surface orientation of the oxynitride semiconductor. These are indeed topics of fundamental importance since it is exactly at the surface where the visible light-driven electrochemical reaction takes place. In contrast to conventional powder samples, thin films represent the best model system for these investigations. This study reviews current state-of-the-art of oxynitride thin film fabrication and characterization before focusing on LaTiO2N selected as representative photocatalyst. We report the investigation of the initial physicochemical evolution of the surface. Then we show that, after stabilization, the absorbed photon-to-current conversion efficiency of epitaxial thin films can differ by about 50% for different crystallographic surface orientations and be up to 5 times larger than for polycrystalline samples.

A current challenge in the field of magnetoelectric multiferroics is to identify systems that allow a controlled tuning of states displaying distinct magnetoelectric responses. Here we show that the multiferroic ground state of the archetypal multiferroic TbMnO3 is dramatically modified by epitaxial strain. Neutron diffraction reveals that in highly strained films the magnetic order changes from the bulk-like incommensurate bc-cycloidal structure to commensurate magnetic order. Concomitant with the modification of the magnetic ground state, optical second-harmonic generation (SHG) and electric measurements show an enormous increase of the ferroelectric polarization, and a change in its direction from along the c- to the a-axis. Our results suggest that the drastic change of multiferroic properties results from a switch of the spin-current magnetoelectric coupling in bulk TbMnO3 to symmetric magnetostriction in epitaxially-strained TbMnO3. These findings experimentally demonstrate that epitaxial strain can be used to control single-phase spin-driven multiferroic states., Scientific Reports, 7, ISSN:2045-2322

In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm2 the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

In this study, we investigate both experimentally and numerically laser-induced forward transfer (LIFT) of thin films to determine the role of a thin polymer layer coating the receiver with the aim of modifying the rate of deceleration and reduction of material stress preventing intact material transfer. A numerical model of the impact phase during LIFT shows that such a layer reduces the modelled stress. The evolution of stress within the transferred deposit and the substrate as a function of the thickness of the polymer layer, the transfer velocity and the elastic properties of the polymer are evaluated. The functionality of the polymer layer is verified experimentally by LIFT printing intact 1- $$\upmu $$ m-thick bismuth telluride films and polymeric light-emitting diode pads onto a layer of 12- $$\upmu $$ m-thick polydimethylsiloxane and 50-nm-thick poly(3,4-ethylenedioxythiophene) blended with poly(styrenesulfonate) (PEDOT:PSS), respectively. Furthermore, it is demonstrated experimentally that the introduction of such a compliant layer improves adhesion between the deposit and its substrate.

A photoanode structure for dye-sensitized solar cells has been applied into the photocatalytic/electrochemical cooperative degradation of methylene blue solutions. The low eutectic point of titanium dioxide (TiO2) with a fluorine-doped tin dioxide (FTO) conductive layer results in a high reactivity of TiO2 for the photocatalytic process as well as a good electron transfer for the electrochemical process. The porous TiO2 layer maintains a large surface area for the degradations. Through the combinational process, the degradation velocity was improved by ~36%, compared to a pure photocatalytic process.

The UltraScan data analysis application is a software package that is able to take advantage of computational resources in order to support the interpretation of analytical ultracentrifugation experiments. Since 2006, the UltraScan scientific gateway has been used with Web browsers in TeraGrid by scientists studying the solution properties of biological and synthetic molecules. UltraScan supports its users with a scientific gateway in order to leverage the power of supercomputing. In this contribution, we will focus on several advancements of the UltraScan scientific gateway architecture with a standardized job management while retaining its lightweight design and end user interaction experience. This paper also presents insights into a production deployment of UltraScan in Europe. The approach is based on open standards with respect to job management and submissions to the Extreme Science and Engineering Discovery Environment in the USA and to similar infrastructures in Europe such as the European Grid Infrastructure or the Partnership for Advanced Computing in Europe PRACE. Our implementation takes advantage of the Apache Airavata framework for scientific gateways that lays the foundation for easy integration into several other scientific gateways. Copyright © 2014 John Wiley & Sons, Ltd.

We performed a comparative study on the photoelectrochemical performance of LaTaON

Strain engineering is the art of inducing controlled lattice distortions in a material to modify specific physicochemical properties. Strain engineering is applied not only for basic fundamental studies of physics and chemistry of solids but also for device fabrication through the development of materials with new functionalities. Thin films are one of the most important tools for strain engineering. Thin films can in fact develop large strain due to the crystalline constraints at the interface with the substrate and/or as a result of specific morphological features that can be selected by an appropriate tuning of the deposition parameters. Within this context, the in situ measurement of the substrate curvature is a powerful diagnostic tool allowing real time monitoring of the stress state of the growing film. This paper reviews a few recent applications of this technique and presents new measurements that point out the great potentials of the substrate curvature measurement in strain engineering. Our study also shows how, due to the high sensitivity of the technique, the correct interpretation of the results can be in certain cases not trivial and require complementary characterizations and an accurate knowledge of the physicochemical properties of the materials under investigation.

The diffusion in fast oxygen ion conductors is typically analyzed by isotope exchange experiments followed by secondary ion mass spectrometry (SIMS). This study demonstrates confocal Raman spectroscopy in combination with beveling of the specimen's surface as an interesting non-UHV alternative to SIMS. This simple and comparably inexpensive approach is shown to result in practically the same values for the diffusion properties as the SIMS technique. Thereby, the limitations of both techniques are compared for an easy understanding under which conditions they are applicable.

The oxygen diffusion kinetics in a strontium titanate (STO)–yttria stabilized zirconia (YSZ) heterostructure were investigated by secondary ion mass spectrometry (SIMS) depth profiling of pulsed laser deposited thin films grown on 18 O enriched single crystalline substrates. By annealing for 100 h at 1100 °C in an 18 O 2 enriched atmosphere 18 O concentrations of ~ 81% and ~ 63% were reached in the YSZ, and STO substrates, respectively. The film depositions were performed at different substrate temperatures up to 750 °C and different oxygen background pressures in a range from 1.5 × 10 − 5 mbar to 0.1 mbar to observe differences in the diffusion of the oxygen ions from the substrate into the films. Flat profiles of 18 O were obtained for the YSZ thin films implying a very fast diffusion that determines the isotope distribution during the deposition. For the STO films pronounced concentration profiles were obtained at 650 °C allowing estimations of the diffusion constant. Elemental mapping of the YSZ films revealed pinholes of micron size which are hardly detectable by other techniques.

The evolution of Lu and LuO species in a laser ablation plasma from different targets has been investigated by simultaneously performing mass spectrometry and plasma imaging. Ablation was achieved with a 248 nm KrF laser from a Lu, a Lu 2 O 5 and a LuMnO 3 target under different background gas conditions. Mass spectrometry measurements show very similar intensities and ratios for the respective species for all three targets under the same ablation conditions. This indicates only a small influence of the target on the final Lu and LuO contents in the plasma, with the major influence coming from collisions with the background gas. Furthermore, spatially, timely and spectrally resolved plasma imaging was utilized to clearly identify the shockwave at the plasma front as the main region for Lu oxidation. A strong decrease of Lu intensities together with a directly correlated increase of LuO was observed toward the outer regions of the plasma.

Oxygen is one of the most commonly used background gases for pulsed laser deposition of oxide thin films. In this work the properties of a 308 nm laser-induced La 0.4 Ca 0.6 MnO 3 plasma were analyzed using a quadrupole mass spectrometer combined with an energy analyzer, to investigate the interaction between the various plasma species and the background gas. The composition and kinetic energies of the plasma species were compared in vacuum and an O 2 background gas at different pressures. It has been observed that the O 2 background gas decreases the kinetic energy of the positively charged atomic plasma species. In addition, the interaction with the O 2 background gas causes the generation of positive diatomic oxide species of LaO + , CaO + and MnO + . The amount of negatively charged diatomic or tri-atomic oxide species decreases in the O 2 background compared to vacuum, while the amount of O 2 − increases strongly.

The use of LIFT (Laser Induced Forward Transfer) for localized and high spatial resolution printing of many types of functional organic and inorganic, biological or synthetic materials onto substrates is an effective method in various domains (electronics, sensors, and surface biofunctionalization). Although extensive research has been dedicated to the LIFT process in the last years, there is an increasing interest for combining the advantages of this technique with specific materials characteristics for obtaining localized structures or for creating physical guidance structures that could be used as biological scaffolds. Within this context, we aim to study a new aspect related to combining the advantages of Dynamic Release Layer assisted LIFT (DRL-LIFT) with a soft substrate (i.e. Thermanox) for obtaining surface functionalization with micro and nano “porous” polymeric structures. The structures obtained with different topographical properties were evaluated by scanning electron microscopy, atomic force microscopy, optical and fluorescence microscopy. Subsequently, the structures were used as a base for cellular behavior study platforms. Preliminary in vitro tests involving two types of cells, fibroblast and oligodendrocytes, were performed on these LIFT printed platforms.

Laser-induced forward transfer (LIFT) has already been used to fabricate various types of organic light-emitting diodes (OLEDs), and the process itself has been optimised and refined considerably since OLED pixels were first demonstrated. In particular, a dynamic release layer (DRL) of triazene polymer has been used, the environmental pressure has been reduced down to a medium vacuum, and the donor receiver gap has been controlled with the use of spacers. Insight into the LIFT process's effect upon OLED pixel performance is presented here, obtained through optimisation of three-colour polyfluorene-based OLEDs. A marked dependence of the pixel morphology quality on the cathode metal is observed, and the laser transfer fluence dependence is also analysed. The pixel device performances are compared to conventionally fabricated devices, and cathode effects have been looked at in detail. The silver cathode pixels show more heterogeneous pixel morphologies, and a correspondingly poorer efficiency characteristics. The aluminium cathode pixels have greater green electroluminescent emission than both the silver cathode pixels and the conventionally fabricated aluminium devices, and the green emission has a fluence dependence for silver cathode pixels. (C) 2012 Elsevier B.V. All rights reserved.

This paper presents a theoretical analysis of the processes in thin solid films irradiated by short and ultrashort laser pulses in the regimes of film structuring and laser-induced forward transfer. The regimes are considered at which vaporization of the film materials is insignificant and film dynamics is governed mainly by mechanical processes. Thermoelastoplastic modeling has been performed for a model film in one- and two-dimensional geometries. A method has been proposed to estimate the height of microbumps produced by nanosecond laser irradiation of solid films. Contrary to femtosecond laser pulses, in nanosecond pulse regimes, stress waves across the film are weak and cannot induce film damage. The main role in laser-induced dynamics of irradiated films is played by radial thermal stresses which lead to the formation of a bending wave propagating along the film and drawing the film matter to the center of the irradiation spot. The bending wave dynamics depends on the hardness of the substrate underlying the film. The causes of the receiver substrate damage sometimes observed upon laser-induced forward transfer in the scheme of the direct contact between the film and the receiver are discussed.

The Lanczos process constructs a sequence of orthonormal vectors v_m spanning a nested sequence of Krylov subspaces generated by a hermitian matrix A and some starting vector b. In this paper we show how to cheaply recover a secondary Lanczos process starting at an arbitrary Lanczos vector v_m. This secondary process is then used to efficiently obtain computable error estimates and error bounds for the Lanczos approximations to the action of a rational matrix function on a vector. This includes, as a special case, the Lanczos approximation to the solution of a linear system Ax = b. Our approach uses the relation between the Lanczos process and quadrature as developed by Golub and Meurant. It is different from methods known so far because of its use of the secondary Lanczos process. With our approach, it is now in particular possible to efficiently obtain {\em upper bounds} for the error in the {\em 2-norm}, provided a lower bound on the smallest eigenvalue of $A$ is known. This holds in particular for a large class of rational matrix functions including best rational approximations to the inverse square root and the sign function. We compare our approach to other existing error estimates and bounds known from the literature and include results of several numerical experiments.

The nitrogen substitution into the oxygen sites of several oxide materials leads to a reduction of the band gap to the visible-light energy range, which makes these oxynitride semiconductors potential photocatalysts for efficient solar water splitting. Oxynitrides typically show a different crystal structure compared to the pristine oxide material. As the band gap is correlated to both the chemical composition and the crystal structure, it is not trivial to distinguish which modifications of the electronic structure induced by the nitrogen substitution are related to compositional and/or structural effects. Here, X-ray emission and absorption spectroscopy are used to investigate the electronic structures of orthorhombic perovskite LaTiO

A current challenge in the field of magnetoelectric multiferroics is to identify systems that allow a controlled tuning of states displaying distinct magnetoelectric responses. Here we show that the multiferroic ground state of the archetypal multiferroic TbMnO3 is dramatically modified by epitaxial strain. Neutron diffraction reveals that in highly strained films the magnetic order changes from the bulk-like incommensurate bc-cycloidal structure to commensurate magnetic order. Concomitant with the modification of the magnetic ground state, optical second-harmonic generation (SHG) and electric measurements show an enormous increase of the ferroelectric polarization, and a change in its direction from along the c- to the a-axis. Our results suggest that the drastic change of multiferroic properties results from a switch of the spin-current magnetoelectric coupling in bulk TbMnO3 to symmetric magnetostriction in epitaxially-strained TbMnO3. These findings experimentally demonstrate that epitaxial strain can be used to control single-phase spin-driven multiferroic states.

The performance of a novel low-maintenance tube reactor for ultrasonic treatment of sludge has been evaluated. The effects of sonication on the release of soluble chemical oxygen demand (sCOD) and anaerobic digestibility of raw and digested sewage sludge as well as agricultural sludge were studied. Results suggest that solubilization and digestibility is dependent on both type of sludge and the energy input. Digested and raw sludge showed high degree of solubilization, however, methane production was only increased for digested sludge. Agricultural sludge was not significantly affected by ultrasonic treatment neither concerning sCOD release nor methane production. The configuration of the ultrasonic system (serial vs. parallel operation) did not show a significant difference in both sCOD release and methane production. However, parallel operation tends to perform better for digested sludge, while serial operation tends to perform better for raw sludge. The strongest effect was observed for the treatment of digested sludge by increasing the methane production by more than 60%, although with a very intensive energy input of more than 5,000 kJ per kg total solids. Hence, tube reactors seem to be an attractive alternative to sonotrode-based systems achieving similar performance at low maintenance with great potential especially for digested sludge.

Magnetoelectric multiferroics hold great promise for electrical control of magnetism or magnetic control of ferroelectricity. However, single phase ferroelectric materials with a sizeable ferromagnetic magnetization are rare. Here, we demonstrate that a single-phase orthorhombic $\mathrm{LuMn}{\mathrm{O}}_{3}$ thin film features coexisting magnetic and ferroelectric orders. The temperature dependence of the different order parameters are presented with ferromagnetic order appearing below 100 K and thus at much higher temperatures than ferroelectricity or antiferromagnetism $({T}_{\mathrm{N}},{T}_{\mathrm{FE}}\ensuremath{\le}40\phantom{\rule{0.16em}{0ex}}\mathrm{K})$.

International audience; After a detailed analysis of possible sources of systematic uncertainty, ab-initio Nf =2+1 resultsfor the up-down and strange quark content - with pion masses all the way down to the physicalpoint - are presented and discussed.

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.

Gas sensors based on tin oxide (SnO2) and palladium doped SnO2 (Pd:SnO2) active materials are fabricated by a laser printing method, i.e. reactive laser-induced forward transfer (rLIFT). Thin films from tin based metal-complex precursors are prepared by spin coating and then laser transferred with high resolution onto sensor structures. The devices fabricated by rLIFT exhibit low ppm sensitivity towards ethanol and methane as well as good stability with respect to air, moisture, and time. Promising results are obtained by applying rLIFT to transfer metal-complex precursors onto uncoated commercial gas sensors. We could show that rLIFT onto commercial sensors is possible if the sensor structures are reinforced prior to printing. The rLIFT fabricated sensors show up to 4 times higher sensitivities then the commercial sensors (with inkjet printed SnO2). In addition, the selectivity towards CH4 of the Pd:SnO2 sensors is significantly enhanced compared to the pure SnO2 sensors. Our results indicate that the reactive laser transfer technique applied here represents an important technical step for the realization of improved gas detection systems with wide-ranging applications in environmental and health monitoring control.

Many properties of materials can be changed by varying the interatomic distances in the crystal lattice by applying stress. Ideal model systems for investigations are heteroepitaxial thin films where lattice distortions can be induced by the crystallographic mismatch with the substrate. Here we describe an in situ simultaneous diagnostic of growth mode and stress during pulsed laser deposition of oxide thin films. The stress state and evolution up to the relaxation onset are monitored during the growth of oxygen ion conducting Ce0.85Sm0.15O2-δ thin films via optical wafer curvature measurements. Increasing tensile stress lowers the activation energy for charge transport and a thorough characterization of stress and morphology allows quantifying this effect using samples with the conductive properties of single crystals. The combined in situ application of optical deflectometry and electron diffraction provides an invaluable tool for strain engineering in Materials Science to fabricate novel devices with intriguing functionalities., Nature Communications, 7, ISSN:2041-1723

Human brain atlases [1] are indispensable tools to achieve a better understanding of the multilevel organization of the brain through integrating and analyzing data from different brains, sources, and modalities while considering the functionally relevant topography of the brain [4]. The spatial resolution of most of these electronic atlases is in the range of millimeters, which does not allow the integration of the information at the level of cortical layers, columns, microcircuits or cells. Therefore, we introduced in 2013 the first BigBrain data set with a resolution of 20 \(\upmu \)m isotropic. This data set allows to specify morphometric parameters of human brain organization, which serve as a “gold standard” for neuroimaging data obtained at a lower spatial resolution. It provides, in addition, an essential basis for realistic brain models concerning structural analysis and simulation [2]. For the generation of other, even higher-resolution data sets of the human brain, we developed an improved and more efficient data processing workflow employing high performance computing to 3D reconstruct histological data sets. To facilitate the analysis of intersubject variability on a microscopic level, the new processing framework was applied for reconstructing a second BigBrain data set with 7676 sections. Efficient data processing of a large amount of data sets with a complex nested reconstruction workflow using large number of compute nodes required optimized distributed processing workflows as well as parallel programming. A detailed documentation of the processing steps and the complex inter-dependencies of the data sets at each level of the multi-step reconstruction workflow was essential to enable transformations to images of the same histological sections obtained with even higher spatial resolution. We have addressed these challenges, and achieved efficient high throughput processing of thousands of images of histological sections in combination with sufficient flexibility, based on an effective, successive coarse-to-fine hierarchical processing.

Epitaxial thin films of the proton conducting perovskite BaZr0.53In0.47O3-dH0.47–2d grown by pulsed laser deposition were investigated in their hydrated and dehydrated conditions through a multitechnique approach with the aim to study the structure and proton concentration depth profile and their relationship to proton conductivity. The techniques used were X ray diffraction X ray and neutron reflectivity nuclear reaction analysis and Rutherford backscattering together with impedance spectroscopy. The obtained proton conductivity and activation energy are comparable to literature values for the bulk conductivity of similar materials thus showing that grain boundary conductivity is negligible due to the high crystallinity of the film. The results reveal an uneven proton concentration depth profile with the presence of a 3–4 nm thick proton rich layer with altered composition likely characterized by cationic deficiency. While this surface layer either retains or reobtains protons after desorption and cooling to room temperature the bulk of the film absorbs and desorbs protons in the expected manner. It is suggested that the protons in the near surface proton rich region are located in proton sites characterized by relatively strong O–H bonds due to weak hydrogen bond interactions to neighboring oxygen atoms and that the mobility of protons in these sites is generally lower than in proton sites associated with stronger hydrogen bonds. It follows that strongly hydrogen bonding configurations are important for high proton mobility.

Decoding the human brain is perhaps the most fascinating scientific challenge in the 21st century. The Human Brain Project (HBP), a 10-year European Flagship, targets the reconstruction of the brain's multi-scale organization. It uses productive loops of experiments, medical, data, data analytics, and simulation on all levels that will eventually bridge the scales. The HBP IT architecture is unique, utilizing cloud-based collaboration and development platforms with databases, workflow systems, petabyte storage, and supercomputers. The HBP is developing toward a European research infrastructure advancing brain research, medicine, and brain-inspired information technology.

The electrical conductivity of dense and nanoporous zirconia-based thin films is compared to results obtained on bulk yttria stabilized zirconia (YSZ) ceramics. Different thin film preparation methods are used in order to vary grain size, grain shape, and porosity of the thin films. In porous films, a rather high conductivity is found at room temperature which decreases with increasing temperature to 120 °C. This conductivity is attributed to proton conduction along physisorbed water (Grotthuss mechanism) at the inner surfaces. It is highly dependent on the humidity of the surrounding atmosphere. At temperatures above 120 °C, the conductivity is thermally activated with activation energies between 0.4 and 1.1 eV. In this temperature regime the conduction is due to oxygen ions as well as protons. Proton conduction is caused by hydroxyl groups at the inner surface of the porous films. The effect vanishes above 400 °C, and pure oxygen ion conductivity with an activation energy of 0.9 to 1.3 eV prevails. The same behavior can also be observed in nanoporous bulk ceramic YSZ. In contrast to the nanoporous YSZ, fully dense nanocrystalline thin films only show oxygen ion conductivity, even down to 70 °C with an expected activation energy of 1.0 ± 0.1 eV. No proton conductivity through grain boundaries could be detected in these nanocrystalline, but dense thin films.