Abstract: Inelastic image simulation software is presented, implementing the double channeling approximation which takes into account the combination of multiple elastic and single inelastic scattering in a crystal. The approach is described with a density matrix formalism. Two applications in high resolution energy filtered (EFTEM) transmission electron microscopy (TEM) images are presented: thickness-defocus maps for SrTiO3 and exit plane intensities for an (LaAlO3)3(SrTiO3)3 multilayer system. Both systems show a severe breakdown in direct interpretability which becomes worse for higher acceleration voltages, thicker samples and lower excitation edge energies. Since this effect already occurs in the exit plane intensity, it is a fundamental limit and image simulations in EFTEM are indispensable just as they are indispensable for elastic high resolution TEM images.

Abstract: This paper discusses the possibility of retrieving the electron distribution (with highlighted valence electron distribution information) of materials from recorded HREM images. This process can be achieved by solving two inverse problems: reconstruction of the exit wave and reconstruction of the electron distribution from exit waves. The first inverse problem can be solved using a focal series reconstruction method. We show that the second inverse problem can be solved by combining a series of exit waves recorded at different thickness conditions. This process is designed based on an improved understanding of the dynamical scattering process. It also explains the fundamental difficulty of obtaining the valence electron distribution information and the basis of our solution.

Abstract: First results on the imaging of intact metalorganic framework (MOF) pores in MOF-5 nanocrystals by aberration corrected transmission electron microscopy (TEM) under liquid nitrogen conditions are presented. The applied technique is certainly transferable to other MOF systems, permitting detailed studies of MOF interfaces, MOFnanoparticle interaction and MOF thin films.

Abstract: The use of non-invasive macroscopic imaging techniques is becoming more prevalent in the field of cultural heritage, especially to avoid invasive procedures that damage valuable artworks. For this purpose, an X-ray powder diffraction scanner (MA-XRPD) capable of visualising crystalline compounds in a highly specific manner was recently developed. Many inorganic pigments present in paintings fall into this category of materials. In this study, the 17th century oil painting Girl with a Pearl Earring (c. 1665) by Johannes Vermeer was analysed with a combination of transmission and reflection mode MA-XRPD. By employing this scanner in reflection mode, the relative sensitivity for compounds that are present at the paint surface could be increased, establishing it as a highly relevant technique for investigating the degradation processes that are ongoing at paint surfaces. Many of the original pigments employed by Vermeer could be identified, along with four secondary alteration products: gypsum (CaSO4 center dot 2H(2)O), anglesite (PbSO4), palmierite (K2Pb(SO4)(2)) and weddellite (CaC2O4 center dot 2H(2)O). The formation of gypsum was linked to the presence of chalk in the upper glaze layer while the formation of palmierite and weddellite is driven by the presence of lake pigments (and their substrates). In this manner, MA-XRPD can also be used to pinpoint locations relevant for sampling and synchrotron mu-XRPD analysis, which provides information on the microscopic make-up of the paint. A paint cross-section taken from an area rich in palmierite was analysed with synchrotron mu-XRPD, which confirmed the presence of this secondary compound at the interface of the upper paint layer with the ground layer as well as the presence of anglesite in the ground layer. The capacity of MA-XRPD to identify and chart secondary alteration products in a non-invasive manner has only very recently been demonstrated and makes it a highly relevant technique for the assessment of the chemical condition of works of art.

Abstract: Different types of titanosilicates are synthesized, structurally characterized, and subsequently catalytically tested in the liquid-phase epoxidation of cyclohexene. The performance of three types of combined zeolitic/mesoporous materials is compared with that of widely studied Ti-grafted-MCM-41 molecular sieve and the TS-1 microporous titanosilicate. The catalytic test results are correlated with the structural characteristics of the different catalysts. Moreover, for the first time, immersion calorimetry with the same substrate molecule as in the catalytic test reaction is applied as an extra means to interpret the catalytic results. A good correlation between catalytic performance and immersion calorimetry results is found. This work points out that the combination of catalytic testing and immersion calorimetry can lead to important insights into the influence of the materials structural characteristics on catalysis. Moreover, the potential of using immersion calorimetry as a screening tool for catalysts in epoxidation reactions is shown.

Abstract: Cancer immunotherapy is a promising strategy that engages the patient's immune system to kill cancer cells selectively while sparing normal tissue. Treatment of macrophages with a nanosecond-pulsed dielectric barrier discharge directly enhanced their cytotoxic activity against tumor cells but not normal cells. These results underscore the clinical potential of plasma for cancer immunotherapy.

Abstract: Sr2FeO3+x F1-x (x = 0.08, 0.2), an n = 1 Ruddlesden-Popperphase, was synthesized from the oxidationof Sr2FeO3F in air at high temperature followinga fluorine for oxygen substitution and Fe3+ to Fe4+ oxidation. A structural investigation of both compounds was performedusing complementary and high-resolution techniques (Synchrotron X-rayand electron diffraction, Mo''ssbauer spectroscopy, HR-STEM)coupled to DFT calculation. This study reveals that oxidation leadsto a high degree of apical anion disorder coupled to antiphase boundaries. Sr2FeO3F, an oxyfluoride compoundwith an n = 1 Ruddlesden-Popper structure,was identifiedas a potential interesting mixed ionic and electronic conductor (MIEC).The phase can be synthesized under a range of different pO(2) atmospheres, leading to various degrees of fluorinefor oxygen substitution and Fe4+ content. A structuralinvestigation and thorough comparison of both argon- and air-synthesizedcompounds were performed by combining high-resolution X-ray and electrondiffraction, high-resolution scanning transmission electron microscopy,Mo''ssbauer spectroscopy, and DFT calculations. While the argon-synthesizedphase shows a well-behaved O/F ordered structure, this study revealedthat oxidation leads to averaged large-scale anionic disorder on theapical site. In the more oxidized Sr2FeO3.2F0.8 oxyfluoride, containing 20% of Fe4+, two differentFe positions can be identified with a 32%/68% occupancy (P4/nmm space group). This originates due to the presenceof antiphase boundaries between ordered domains within the grains.Relations between site distortion and valence states as well as stabilityof apical anionic sites (O vs F) are discussed. This study paves theway for further studies on both ionic and electronic transport propertiesof Sr2FeO3.2F0.8 and its use in MIEC-baseddevices, such as solid oxide fuel cells.

Abstract: Marine recirculating aquaculture system (MRAS) is an effective technology that provides sustainable farming of food fish globally. However, dissolved organics material (chemical oxygen demand, COD) and especially ammonia are produced from uneaten feed and metabolic wastes of fish. To purify the MRAS water, this study adopted a sequencing biofilm batch reactor (SBBR) and comparatively investigated the performances of four different carriers on ammonia and COD removal. Results indicated that the NH4+-N removal rates were 0.045 +/- 0.05, 0.065 +/- 0.008, 0.089 +/- 0.005, and 0.093 +/- 0.003 kg/(m(3)center dot d), and the COD removal rates were 0.019 +/- 0.010, 0.213 +/- 0.010, 0.255 +/- 0.015, and 0.322 +/- 0.010 kg/(m(3)center dot d) in the SBBRs packed with porous plastic, bamboo ring, maifan stone, and ceramsite carriers, respectively. Among the four carriers, ceramsite exhibited the best performance for both NH4+-N (80%) and COD (33%) removal after the SBBR reached the steady-state operation conditions. For all carriers studied, the NH4+-N removal kinetics could be well simulated by the first-order model, and the NH4+-N and COD removal rates were logarithmically correlated with the carrier's specific surface area. Due to its high ammonia removal, stable performance and easy operation, the ceramsite-packed SBBR is feasible for MRAS water treatment.

Abstract: Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness.

Abstract: Three-dimensional topological insulators are exotic materials with unique properties. Tetradymite type binary chalcogenides of bismuth and antimony, as well as their mixed crystals, belong to prototypical TIs. Potential device applications of these materials require in-depth knowledge of their stability in the ambient atmosphere and other media maintained during their processing. Here we investigated the reactivity of mixed crystals with anion substitution, Bi-2(Se1-xTex)(3) and Sb2(Se1-xTex)(3), towards molecular oxygen using both in situ and ex situ X-ray photoelectron spectroscopy. The results indicate that, in contrast to cation substitution, partial substitution of tellurium by selenium atoms leads to anomalously high surface reactivity, which even exceeds that of the most reactive binary constituent. We attribute this effect to anion ordering that essentially modifies the bond geometry, especially the respective bond angles as modeled by DFT.

Abstract: Indium oxide based transparent conductive oxides (TCOs) are promising contact layers in solar cells due to their outstanding electrical and optical properties. However, when applied in Cu(In,Ga)Se-2 or Si-hetero-junction solar cells the specific roughness of the material beneath can affect the growth and the properties of the TCO. We investigated the electrical properties of hydrogen doped and hydrogen-tungsten co-doped indium oxides grown on rough Cu(In,Ga)Se-2 samples as well as on textured and planar glass. At sharp ridges and V-shaped valleys crack-shaped voids form inside the indium oxide films, which limit the effective electron mobility of the In2O3:H and In2O3:H,W thin films. This was found for films deposited by magnetron sputtering and reactive plasma deposition at several deposition parameters, before as well as after annealing and solid phase crystallization. This suggests universal behavior that will have a wide impact on solar cell devices.

Abstract: We utilize an exact variational numerical procedure to calculate the ground state properties of a polaron in the presence of a Rashba-like spin-orbit interaction. Our results corroborate previous work performed with the momentum average approximation and with weak-coupling perturbation theory. We find that spin-orbit coupling increases the effective mass in the regime with weak electron-phonon coupling, and decreases the effective mass in the regimes of intermediate and strong electron-phonon coupling. Analytical strong-coupling perturbation theory results confirm our numerical results in the small-polaron regime. A large amount of spin-orbit coupling can lead to a significant lowering of the polaron effective mass.

Abstract: The unique capabilities of microsecond dwell time (DT) single-particle inductively coupled plasma mass spectrometry (spICPMS) were utilized to characterize the cloud of ions generated from the introduction of suspensions of gold nanoparticles (AuNPs) into the plasma. A set of narrowly distributed particles with diameters ranging from 15.4 to 100.1 nm was synthesized and characterized according to established protocols. Statistically significant numbers of the short transient spICPMS events were evaluated by using 50 μs DT for their summed intensity, maximum intensity, and duration, of which all three were found to depend on the particle diameter. The summed intensity increases from 10 to 1661 counts and the maximum intensity from 6 to 309 counts for AuNPs with diameters from 15.4 to 83.2 nm. The event duration rises from 322 to 1007 μs upon increasing AuNP diameter. These numbers represent a comprehensive set of key data points of the ion clouds generated in ICPMS from AuNPs. The extension of event duration is of high interest to appoint the maximum possible particle number concentration at which separation of consecutive events in spICPMS can still be achieved. Moreover, the combined evaluation of all above-mentioned ion cloud characteristics can explain the regularly observed prolonged single-particle events. The transport and ionization behavior of AuNPs in the ICP was also computationally modeled to gain insight into the size-dependent signal generation. The simulated data reveals that the plasma temperature, and therefore the point of ionization of the particles, is the same for all diameters. However, the maximum number density of Au+, as well as the extent of the ion cloud, depends on the particle diameter, in agreement with the experimental data, and it provides an adequate explanation for the observed ion cloud characteristics.

Abstract: As real-life experimental data on natural ventilation of atmospheric pollution levels in urban street canyons is still scarce and has proven to be complex, this study, experimentally evaluated the impact of an urban street canyon opening on local atmospheric pollution levels, during a 2-week field campaign in a typical urban street canyon in Antwerp, Belgium. Besides following up on atmospheric particulate matter (PM), ultrafine particles (UFPs) and black carbon (BC) levels, the magneto-chemical PM10 composition was quantified to identify contributions of specific elements in enclosed versus open street canyon sections. Results indicated no higher overall PM, UFP and BC concentrations at the enclosed site compared to the open site, but significant day-to-day variability between both monitoring locations, depending on the experienced wind conditions. On days with oblique wind regimes (4 out of 14), natural ventilation was observed at the open location while higher element contributions of Ca, Fe, Co, Ni, Cu, Zn and Sr were exhibited at the enclosed location. Magnetic properties correlated with the PM10 filter loading, and elemental content of Fe, Cr, Mn and Ti. Magnetic bivariate ratios identified finel-grained magnetite carriers with grain sizes below 0.1 μm, indicating similar magnetic source contributions at both monitoring locations. Our holistic approach, combining atmospheric monitoring with magneto-chemical PM characterization has shown the complex impact of real-life wind flow regimes, different source contributions and local traffic dynamics on the resulting pollutant concentrations and contribute to a better understanding on the urban ventilation processes of atmospheric pollution.