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Kammern-Grubgraben is among the few stratified Upper Palaeolithic sites in Central Europe dating to the Last Glacial Maximum which provided not only substantial amounts of archaeological materials but also extensive preserved occupational structures. Although the site has been known since the last quarter of the 19th century, systematic excavations didn't start until the 1980's. These were carried out subsequently by two different teams providing partly incongruent observations and interpretations. Renewed field investigations commenced in 2015 and aim at reassessing stratigraphy and chronology, settlement structures and occupational sequence, as well as mobility and economy. First results provide a robust multi-method chrono-stratigraphic bracket for occupation between Greenland Stadials GS-3 and GS-2.1. Artefact technology and typology point at supra-regional contacts to both the west and east on a more general scale while a high degree of mobility is specifically demonstrated for the hunter-gatherer groups occupying the site by displaying procurement patterns for various raw materials targeting not only local, but also regional and far-distance sources. Furthermore, the new investigations have been able to almost double the previously established site extent, and targeted excavations show that the diversity and complexity of stone constructions considerably exceeds what has previously been observed. [ABSTRACT FROM AUTHOR]

Since 2005, annual excavation campaigns have been conducted at the open air site of Krems-Wachtberg in eastern Austria. This paper provides an overview of the preliminary archaeological results, including a presentation of the site's Upper Palaeolithic features and find inventories, as well as a discussion of its position within the Gravettian of the Middle Danube region. The site is characterized by a well-developed occupation layer with associated features like hearths and burials. From a local perspective, the station is part of an extensive Gravettian settlement cluster on the Wachtberg promontory. Beyond that, more far-ranging connections can be established to sites of the older Gravettian forming the regional group of the Pavlovian. These analogies apply to topographic position and economic factors, as well as to technological and typological criteria of the lithic inventories. Furthermore, parallels in burial rituals and art are evident. [ABSTRACT FROM AUTHOR]

Abstract: Recent archaeological excavations at the Upper Palaeolithic open-air site of Krems-Wachtberg in eastern Austria exposed a late Pleistocene loess sequence. An interdisciplinary sampling strategy was applied to the 8-m high North profile. The extraordinary conservation of a Gravettian living floor with several complex features is discussed in this paper. [Copyright &y& Elsevier]

Abstract: Volume-doped CoTiO3 was synthesized via the polyol method. As volume dopants Gd, Ho, K, La, Li, Na, Pb, Sb, and Sm with a concentration of 2at.% were applied. By X-ray diffraction (XRD) materials structure was confirmed, while the materials morphology was imaged using scanning electron microscopy (SEM). Thick films of the nanocrystalline material were applied with a laboratory robotic system to a 8×8 multielectrode substrate. We show that the p-type semiconducting material doped with various metals is applicable for the fast detection of ethanol and propylene. The volume dopants affect the sensing and response behavior of the base material. [Copyright &y& Elsevier]

Abstract: Perovskite-type LnMO3 (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; M=Cr, Fe) oxides were prepared by the polyol mediated synthesis. Thick films of the prepared materials were electrically characterised using high throughput impedance spectroscopy (HT-IS). All samples showed p-type semiconductivity. Ethanol and propylene were used to test the gas sensing behaviour in a temperature range from 200 to 500°C. A correlation between the (Ln–O) binding energy and the sensing properties is observed. [Copyright &y& Elsevier]

Abstract: p-Type semiconducting nanocrystalline CoTiO3:La (2at.%) was synthesized via polyol method. X-ray diffraction (XRD) was used to confirm the materials structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to image the materials morphology. Thick films of the nanocrystalline material were applied with a laboratory roboting system to an 8×8 multielectrode substrate, developed for high-throughput impedance spectroscopy (HTIS). With this method it was shown that the base material doped with various metals (Au, Ce, Ir, Pd, Pt, Rh, Ru) in different concentrations (0.2–0.6at.%) is applicable for the fast detection of ethanol, propylene and NO2, depending on the surface doping and the operation temperature. [Copyright &y& Elsevier]

Abstract: Assessment of fracture healing is a common problem in orthopaedic practice and research. To determine the effectiveness of certain treatments, drugs, mechanical loads, or rehabilitation regimes, the strength of the fracture callus must be determined. Both clinically and experimentally, there is a need to noninvasively and quantitatively evaluate fracture callus quality during healing. The objective of this study was to develop a method to assess fracture stiffness using micro-computed tomography (micro-CT) and finite element analysis. The method was developed and validated with plastic phantoms of various cross sections and known material properties, tested experimentally in four-point bending and torsion. The method was then applied to fractured rat femurs after 3 and 4 weeks of healing tested experimentally in torsion (50 femurs total). Micro-CT scans were made of the fracture calluses to determine three-dimensional geometry and material properties for the finite element models. Experimentally measured torsional rigidities were compared to finite element solutions. Finite element model predictions of callus rigidity correlated significantly better with experimental torsional rigidity than other common measures of healing progress such as callus area, bone mineral density, or area moment of inertia. Using FEA to predict mechanical properties of the callus could prove to be a useful tool in fracture-healing studies. [Copyright &y& Elsevier]

As a novel strategy to overcome some of the therapeutic disadvantages of 6-thioguanine (TG) and 6-mercaptopurine (MP), we propose the inclusion of these drugs in βcyclodextrin (βCD) to form the complexes βCD-TG and βCD-MP, followed by subsequent interaction with gold nanoparticles (AuNPs), generating the ternary systems: βCD-TG-AuNPs and βCD-MP-AuNPs. This modification increased their solubility and improved their stability, betting by a site-specific transport due to their nanometric dimensions, among other advantages. The formation of the complexes was confirmed using powder X-ray diffraction, thermogravimetric analysis and one and two-dimensional NMR. A theoretical study using DFT and molecular modelling was conducted to obtain the more stable tautomeric species of TG and MP in solution and confirm the proposed inclusion geometries. The deposition of AuNPs onto βCD-TG and βCD-MP via sputtering was confirmed by UV–vis spectroscopy. Subsequently, the ternary systems were characterized by TEM, FE-SEM and EDX to directly observe the deposited AuNPs and evaluate their sizes, size dispersion, and composition. Finally, the in vitro permeability of the ternary systems was studied using parallel artificial membrane permeability assay (PAMPA). [ABSTRACT FROM AUTHOR]

In the course of extensive excavations at the Upper Palaeolithic open-air site of Krems-Wachtberg, a large assemblage as well as extraordinarily well preserved archaeological features have been recovered since 2005. After the completion of the field work, a preliminary overview of the lithic industry can be provided. Artefact-morphological studies allow for the dating of the main cultural layer to the older Gravettian, with specific typological elements indicating an attribution to the Pavlovian stage. Detailed raw material analyses applying stereo-microscopic investigation for all lithic artefacts and geochemical analysis for selected raw material groups revealed a predominantly local raw material economy. Accordingly, the lithic chaîne opératoire is present at the site for most of the identified raw materials. Spatial analyses of selected raw material units in combination with initial refitting-results reflect site formation processes but also indicate specific activity areas within the cultural layer. [ABSTRACT FROM AUTHOR]

Zeolites are in use as catalyst materials in the selective catalytic reduction of NO x with NH 3 as reducing agent. An initial NH 3 -adsorption on the catalyst is essential for the reaction with NO and NO 2 to occur. Due to the adsorbed NH 3 , the proton conductivity of the zeolite increases markedly. This change of the electrical properties of the catalyst material can be monitored in a contactless way and in operando using a radio frequency-based method to determine the ammonia loading on the catalyst. In this work, the ammonia storage is examined on a copper exchanged Chabazite Cu-SSZ-13, a typical SCR catalyst as it is in use for serial applications, at different temperatures and various feed ratios. [ABSTRACT FROM AUTHOR]

Since 2005, detailed archaeological investigations have been carried out at the Upper Palaeolithic site of Krems-Wachtberg in eastern Austria where a well-preserved Gravettian find layer is embedded in an 8 m high Late Pleistocene loess sequence. The excavations are accompanied by interdisciplinary sampling strategies applied on the main profiles' entire sediment series as well as on selected locations within the archaeological context. The latter include both evident anthropogenic structures, an in situ occupation surface with hearths and burials, and periglacial features that together determine the morphology and explain the formation of the main Gravettian find horizon. [ABSTRACT FROM AUTHOR]

The classic Upper Palaeolithic location of the Wachtberg in Krems (eastern Austria) features a multitude of exposures in a limited area of about 50,000 m 2 . In addition to Gravettian sites which have been investigated in detail in the course of recent years using modern methods, there are the records of old excavations, several documented sections, as well as a considerable number of core samples displaying heterogeneous documentation standards. This paper provides an overview of these different sources of information and aims at synthesizing the data for a comprehensive understanding of the local loess sedimentation and Palaeolithic occupation. [ABSTRACT FROM AUTHOR]

The catalytic combustion of methane has gained much attention as a sustainable technology, due to concerns about the environmental impact of unburnt methane emissions from the natural gas vehicles. Researchers have explored alternatives to precious metal catalysts for methane combustion, with a focus on perovskite oxides known for their excellent activity and sintering-resistance capacity. In this study, LaFeO 3 perovskite material was synthesized and subsequently subjected to a nitric acid etching treatment to modify its surface. It was found that the acid preferentially dissolved La cations from LaFeO 3 surface while the perovskite phase was unchanged, as a consequence, the etched LaFeO 3 shows improvement in methane combustion activity. The best performance was achieved in the sample with one-hour surface etched treatment, which suggests that the appropriate surface reconstruction induced by acid treatment promotes the formation of more active Fe sites on the surface and reduces the energic barriers of methane activation. This work presents a straightforward and effective approach to tailor the exposed surface properties of perovskites, thereby enhancing their activity in hydrocarbon combustion reactions. [Display omitted] • Nitrate acid treatment is performed to selectively etch the as-prepared LaFeO 3 perovskite for the surface modification. • Nitric acid preferentially dissolves La cations from LaFeO 3 surface, thus more Fe-O termination are exposed as active sites. • 1-h treated LaFeO 3 shows an enhanced CH 4 combustion reaction activity, due to the lowest energic barriers of CH 4 activation. • This work presents an effective approach to tailor the exposed surface properties of perovskites. [ABSTRACT FROM AUTHOR]

The phase-pure zeolite Y with a high n (Si)/ n (Al) ratio is obtained with the cyclic polyether 15-Crown-5 as a structure-directing agent. In copper-exchanged for this new zeolite outperformed other Cu-containing zeolite Y counterparts during NH 3 -SCR-DeNO x with more than 80% NO conversion and more than 85% N 2 selectivity in the temperature range of 100 – 500 °C. The presence of Cu+ species located in sodalite cages with elevated redox cyclability guarantees high activity and N 2 selectivity up to 400 °C over CuY-Crown. Above 400 °C, a high activity and N 2 selectivity are related to the accessibility of chemisorbed NH 3 to the gaseous NO during the NH 3 -SCR-DeNO x. [Display omitted] • Zeolite Y with a high n (Si)/ n (Al) ratio is obtained using 15-Crown-5. • CuY-Crown outperformed other CuY counterparts in NH 3 -SCR-DeNO x. • Cu+ species located in sodalite cages guarantee high activity and N 2 selectivity. [ABSTRACT FROM AUTHOR]

Abstract: For numerical simulations of biological processes the assignment of reliable material properties is essential. Since literature data show huge variations for each parameter, this study presents a method for determining tissue properties straight from the investigated specimens by combining electronic speckle pattern interferometry (ESPI) with finite element (FE) analysis in a two-step parameter analysis procedure. ESPI displacement data from two mid-sagittal ovine fracture callus slices under 5N compressive load were directly compared to data from FE simulations of the respective experimental setup. In the first step a parameter sensitivity analysis quantified the influence of single tissues on the mechanical behavior of the callus specimens. In the second step, material properties (i.e. Young''s moduli and Poisson''s ratios) for the most dominant material of each callus specimen were determined through a parameter sampling procedure minimizing the mean local deviations between the simulated (FE) and measured (ESPI) equivalent element strains. The resulting material properties showed reasonable ranges downsizing the variability of previous published values, especially for Young''s modulus which was 1881MPa for woven bone and 16MPa for cartilage in average. In conclusion, a numerical method was developed to determine material properties straight from independent fracture callus specimens based on experimentally derived local mechanical conditions. [Copyright &y& Elsevier]

Abstract: Spinel iron oxide nanoparticles of sizes from 12 to 60nm have been prepared via a hydrothermal synthesis. Thick films of the Fe3−x O4 nanoparticles deposited on interdigital electrodes were applied as resistive gas sensors. The electrical and gas sensing properties were characterized by impedance spectroscopy using multielectrode substrates. The reducing analytes CH4, NO, H2 and NH3 in N2 as a reference were applied in order to investigate the sensor response, the selectivity and the recovery behavior at temperature between 50°C and 300°C. The materials exhibit good sensor responses towards NH3 with low cross sensitivities towards H2 and NO at 250°C. A linearly increasing sensor response towards NH3 and H2 with decreasing particle size was found. [Copyright &y& Elsevier]

Abstract: Osteoporosis is a widely spread disease with severe consequences for patients and high costs for health care systems. The disease is characterised by a loss of bone mass which induces a loss of mechanical performance and structural integrity. It was found that transverse trabeculae are thinned and perforated while vertical trabeculae stay intact. For understanding these phenomena and the mechanisms leading to fractures of trabecular bone due to osteoporosis, numerous researchers employ micro-finite element models. To avoid disadvantages in setting up classical finite element models, composite finite elements (CFE) can be used. The aim of the study is to test the potential of CFE. For that, a parameter study on numerical lattice samples with statistically simulated, simplified osteoporosis is performed. These samples are subjected to compression and shear loading. Results show that the biggest drop of compressive stiffness is reached for transverse isotropic structures losing of the trabeculae (minus 89.8% stiffness). The biggest drop in shear stiffness is found for an isotropic structure also losing 32% of the trabeculae (minus 67.3% stiffness). The study indicates that losing trabeculae leads to a worse drop of macroscopic stiffness than thinning of trabeculae. The results further demonstrate the advantages of CFEs for simulating micro-structured samples. [Copyright &y& Elsevier]

Abstract: Background: Internal loads in long bones are of special interest, for testing and optimization of current implant designs for fracture treatment. Inverse dynamic musculoskeletal models were successfully used to determine the muscle forces in the lower extremities, however the internal loads expressed as forces and moments along the human tibia during gait have not been reported. Methods: A musculoskeletal model of the lower extremities, developed and provided under public domain from the AnyBody research group (www.anybody.aau.dk), was modified to determine the three-dimensional internal loads along the tibial axis during gait. To corroborate this numerical model, the calculated resultant hip contact force as well as the axial force on the tibial plateau were compared to in vivo data from the literature. Findings: The highest internal loads were the axial force with up to 4.7 bodyweight and the bending moment in the sagittal plane with up to 71.6 bodyweight times millimetre in the late stance phase. The extreme values of the internal loads along the tibial axis varied up to 1.5 bodyweight and 85.7 bodyweight times millimetre. In the distal part of the tibia, the axial force dominated the three-dimensional internal load case, whereas the internal moments became more significant with increasing distance from the ankle joint. Interpretation: This study provides for the first time the three-dimensional internal loads, expressed as forces and moments along the human tibia during normal gait. The results of this study could be used to improve the mechanical behaviour of current implant designs for the treatment of tibial fractures to avoid implant failures under in vivo loading conditions. [Copyright &y& Elsevier]

Abstract: This study evaluated the feasibility of assessing continuous strain distributions on fracture callus cross-sections with an electronic speckle pattern interferometry (ESPI) system. Mid-sagittal callus cross-sections were harvested from ovine tibiae. One low stiffness (LS) specimen and one high stiffness (HS) specimen were selected to evaluate the feasibility for strain acquisition over a range of callus properties. The HS specimen was 147 times stiffer in compression than the LS specimen. ESPI captured continuous strain distributions on both specimens. Peak strain was located adjacent to cortical boundaries in the osteotomy gap. In response to 5N compression, peak compressive strain of 5.8% in the LS specimen was over two orders of magnitude higher than peak compressive strain of 0.013% in the HS specimen. In conclusion, ESPI-based strain acquisition enables reproducible quantification of strain distributions on callus cross-sections. Such measurements may support validation of computational models and evaluation of experimental results in fracture healing research. [Copyright &y& Elsevier]

Abstract: The workflow of a high throughput screening setup for the rapid identification of new and improved gas sensor materials is presented. The polyol method was applied to prepare nanoparticulate metal oxides as base materials. These materials have been modified by surface and volume doping. Using multielectrode substrates and high throughput impedance spectroscopy (HT-IS) a wide range of materials could be screened on a short time scale. Selected examples reflect the state of the art for applying HT-IS in search of new selective gas sensing materials. [Copyright &y& Elsevier]

Abstract: Background: A number of clinically used total hip femoral implants are claiming a more or less physiologic load transfer, mostly without providing experimental data. To compare three clinically cementless total hip stems of fundamentally different design, the strain distribution before and after insertion in human cadaver femora was measured in vitro. Methods: A conventional straight stem based on a distal anchorage concept, a so-called “anatomic” stem designed to have a proximal force transmission and a “stemless” femoral neck prosthesis were evaluated under similar loading conditions. Strain distribution was measured with tri-axial strain-gauge rosettes before and after implantation of the stems. The same bending moment was used in all femora tested to compare magnitude and direction of the resulting strains. Findings: The straight and the “anatomic” stem both led to a decrease of the longitudinal strains in the proximal femur, while the femoral neck implant mainly led to an increase of measured strains on the lateral side of the greater trochanter. The observed medial strains were closer to physiological values in the “stemless” prosthesis than those of the two full-stem prosthesis. Interpretation: The decrease in strains seen in the proximal region of the femora with implanted conventional hip prosthesis corresponds well to the decrease of bone density in this region noted in clinical follow-up studies. The more physiological strain at the inferior base of the neck seen in “stemless implant” may induce a remodelling process that better retains bone stock in that area. However, the increase of strains noted after implantation of this prosthesis require further investigation to assess the risk they may pose to bone failure. [Copyright &y& Elsevier]

Abstract: Background: Major deficits of many finite element models of the lumbar spine are the oversimplification, assumed constellation of the material properties or the insufficiently performed calibration using experimental in vitro data. The aim of this study was, to develop a method for calibrating the two-composite structure of the annulus fibrosus, the ground substance and collagen fibers. Methods: For that purpose, a three-dimensional, non-linear finite element model of a denucleated intervertebral disc with the adjacent vertebral bodies (L4–L5) was created. Previously performed in vitro experiments provided experimental data for the range of motion in each load direction, needed for calibration. A method was developed to determine the individual contribution of the fibers and the ground substance for bending moments with four different magnitudes (2.5, 5.0, 7.5 and 10Nm). For each bending moment, the stiffness of fibers was varied to approximate the Young’s modulus of the ground substance in order to fulfil the required range of motion obtained from in vitro results within an accuracy of 99%. Results: Infinite material parameter combinations of collagen fibers and ground substance led to the same range of motion, which were different for each bending moment. However, there was only one combination, which was valid for all applied bending moments; and in all load direction. Interpretation: This calibration method was performed on range of motion data; however, the procedure could also be applied to other loading scenarios and measurement parameters like disc bulge, translation and intradiscal pressure. [Copyright &y& Elsevier]

Abstract We describe a facile and simple solid-state thermolysis route for the preparation of Co, Ni, and Fe phosphide nanoparticles embedded in amorphous carbon using an organometallic complex. This was achieved by using a suitable organometallic complex in a single step synthetic route without using any solvent or catalyst. The advantage of using such precursor was to offer a source for metal, phosphorus and carbon without using any additional sources. The morphology of products was characterized by transmission electron microscopy, scanning electron microscopy and nature of carbon was analyzed using the Raman microscope and X-ray diffraction. The electrocatalytic oxygen evolution reaction (OER) activity and stability of the metal phosphide nanostructure was evaluated using the rotating disk electrode technique. The CoP, NiP and FeP exhibit the OER overpotential of 370, 380 and 550 mV at 10 mA cm−2, respectively in 0.1 M KOH electrolyte. Among prepared phosphide catalysts, cobalt phosphide shows a lowest Tafel slope indicate favorable kinetics for the OER activity than nickel and iron phosphide catalysts. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

In Cu-zeolite based selective catalytic reduction of NO x with NH 3 (NH 3 -SCR), Cu species (in particular Cu I ) solvated by NH 3 molecules are predicted theoretically to be highly mobile with their mobility being decisive for the NH 3 -SCR reactivity at low temperatures (<250 °C). Direct experimental observation of the Cu mobility after NH 3 solvation, however, has not been achieved yet. Here we show that complex impedance-based modulus spectroscopy, performed by following the corresponding dielectric relaxation processes at high frequencies (10 4 to 10 6 Hz), can be applied to monitor directly the dynamic local movement of Cu ions in zeolite catalysts under NH 3 -SCR related reaction conditions. Simultaneous in situ impedance and infrared spectroscopy studies, assisted by periodic DFT calculations with reliable van der Waals dispersion corrections, allowed us to identify the key factors determining the local dynamics of Cu ions in two representative Cu-zeolites, i.e. Cu-ZSM-5 and Cu-SAPO-34. The co-adsorption and interaction of NO and NH 3 on Cu II sites led to the formation of highly mobile Cu I species and NH 4 + intermediates, and, consequently, significantly enhanced local dynamics of Cu ions in both zeolite catalysts. The re-oxidation of Cu I , which is the rate-determining step of NH 3 -SCR reaction, was more favorable in Cu-SAPO-34 than in Cu-ZSM-5, which can be attributed to the close coupling of NH 4 + intermediate and Cu site promoting the formation of Cu II -NO 2 /NH 4 + . As a result, the overall local dynamics of Cu, largely determined by Cu I species, is less dependent on the NH 4 + intermediate in Cu-SAPO-34 than in Cu-ZSM-5. [ABSTRACT FROM AUTHOR]

Local to regional paleoenvironmental reactions to past climate changes are preserved in loess-paleosol sequences (LPS). In order to extract this information we used a multi-methodological approach in the Upper Paleolithic site of Krems-Wachtberg East in Lower Austria. Detailed field studies and high-resolution geochemical, colorimetric, and granulometric analyses help to understand the interplay between soil formation, loess accumulation, and surface processes. In comparison to the main profile/excavation of Krems-Wachtberg 2005–2015 it can be stated that OSL- and 14 C-ages as well as the (archeological) stratigraphy of both profiles are comparable. However, pedogenic features are more evident at Krems-Wachtberg East. The new investigations show that well-established weathering indices do not clearly trace interstadial soil formation in the studied profile. Apart from this fact, single specific elements like Fe and Mg react more sensitive to initial pedogenic processes. Weak pedogenesis can further be evidenced by quantitative spectrophotometric results. The latter is also capable of refining and supporting the stratigraphy/pedology based on field analyses. As a general rule, next to loess also initial soil horizons of the MIS 3 are remarkably rich in primary carbonates indicating that soil formation took place in an alkaline environment. Due to the fact that hydrolysis of feldspars could not clearly be detected by the application of pedochemical indices, soil formation was probably limited to the oxidation of iron bearing minerals and weak carbonate leaching. These phases of favorable climatic conditions in terms of pedogenesis were terminated by increasing dust input towards the onset of MIS 2. The eolian deposits are overprinted during reducing conditions in soils and/or modified by colluvial processes. Altogether, weak pedogenesis can be reliably detected using a multi-methodological approach which leads to enhanced paleoenvironmental interpretations. The OSL-ages put the profile in a range of ∼41 to 30 ka. We present a tentative correlation of the studied loess profile to the record of the North Greenland Ice Core Project (NGRIP) for the part of the profile where OSL and 14 C complement each other. [ABSTRACT FROM AUTHOR]

The performance of Cu-chabazite (Cu-CHA) zeolite, the state-of-art catalyst for the ammonia-assisted selective reduction (NH 3 -SCR) of toxic NO x pollutants from heavy-duty diesel vehicles, is insufficient at low reaction temperatures and needs to be improved for meeting stringent emission regulations. Here, we demonstrate that the auto-reduction of isolated Cu sites (i.e. Cu2+[OH]→Cu+) in Cu-CHA could promote the low-temperature NO x abatement efficiency in NH 3 -SCR. Combining in situ spectroscopy, steady-state/transient kinetic measurements and computational simulations, we unveiled that Cu auto-reduction, which was driven by non-oxidative thermal activation, weakened the Cu tethering to CHA framework and thus increased the Cu mobility, particularly, in the presence of NH 3. More importantly, auto-reduction-induced charge redistribution favored NO activation to form intimately interacted Cu+···NO+ pairs, which enabled alternative and highly efficient pathways leading to drastically promoted NO abatement at temperatures below 250 °C. These mechanistic findings shed new light on tuning the speciation of Cu single-sites to promote NO x reduction catalysis over Cu-zeolites. [Display omitted] • Low-temperature NH 3 -SCR promoted by Cu auto-reduction in Cu-CHA zeolite. • Auto-reduction weakened Cu tethering to zeolite framework. • Auto-reduction led to a higher Cu mobility in NH 3 -containing atmosphere. • Highly reactive Cu+-NO+ pairs formed on auto-reduced Cu-CHA in NH 3 -SCR. • The promoting effect of Cu auto-reduction in NH 3 -SCR is universal for Cu-zeolites. [ABSTRACT FROM AUTHOR]

This study demonstrates the effect of polymer topology and molar mass on the electrodeposition of preformed polyelectrolytes. The polyelectrolyte solubility is manipulated electrochemically using a counterion switching approach. Upon this, a triggered film formation occurs upon oxidation of hexacyanoferrate(II). The resulting Pt-electrode deposit consists of polycationic chains, namely poly{[2-(methacryloyloxy)ethyl]trimethylammonium chloride} (PMOTAC), which are physically crosslinked by polymer-complexing ferricyanides. Within this study the architecture of the polyelectrolyte is varied from monomeric units over linear and star-shaped polymers to network-like microgel colloids. Film deposition is observed only for linear and star-shaped polymers being pronounced for shorter linear chains at equimolar charge ratios. Quantification is achieved by help of the deposition efficiency DE obtained by analyzing the currents of a rotating ring disk electrode (RRDE) during hydrodynamic voltammetry. DE relates the amount of deposited ferricyanides to the total amount of electrochemically-produced ferricyanides. DE is used to estimate the deposited mass and film thickness showing good agreement with the film thickness determined experimentally by Scanning Force Microscopy. For future applications these results might help optimizing beneficial film formation or minimizing detrimental film formation during other procedures. [ABSTRACT FROM AUTHOR]

The development of more efficient zeolite catalysts for selective catalytic reduction of NO x by NH 3 (NH 3 -SCR) requires insights into both reaction mechanism and real-time state of the catalyst ( e.g. , the storage level of NH 3 ). Here, we show that impedance spectroscopy (IS) can be applied to sense electrically the uptake of NH 3 into proton-conducting, copper-promoted zeolite catalysts, i.e. , into Cu-ZSM-5 and Cu-SAPO-34. Comparative investigations indicate that Cu-SAPO-34, as compared to Cu-ZSM-5, showed high sensitivity to the change of NH 3 concentration at a broader temperature range. While both zeolites performed similarly for direct monitoring of the SCR conversion of stored NH 3 at temperatures above 350 °C, Cu-SAPO-34 showed a better performance than Cu-ZSM-5 at lower temperatures. A simultaneous IS and diffuse reflection infrared Fourier transform spectroscopy (IS-DRIFTS) study revealed that NH 4 + or NH 4 NO 3 intermediates form on the two zeolite catalysts under SCR-related conditions and affect the proton conductivity at low temperatures, thus influencing significantly the monitoring of SCR conversion of stored NH 3 . The correlation of integral electrical responses with molecular processes, achieved by our simultaneous IS-DRIFTS studies, not only clarifies the origin of the sensing mechanism of zeolite catalysts at a molecular level, but also provides a new perspective to understand the NH 3 -SCR mechanism over metal-promoted zeolites at low reaction temperatures. [ABSTRACT FROM AUTHOR]

In order to meet the legislative emission requirements for NO x -containing exhaust gases, SCR catalysts, in particular zeolites, are used. To improve catalysts and the catalytic processes, an in-depth understanding of the reaction mechanisms is required as well as an analysis of the physicochemical properties of the SCR catalysts, preferably in real-time. Here, we introduce a setup combining impedance spectroscopy and infrared spectroscopy in diffuse reflection mode for in situ measurements on zeolites under SCR-related conditions. This setup allows for the first time to simultaneously monitor both, the proton conductivity of zeolites and the vibration modes of the molecules involved in the catalytic conversion of NO by NH 3 . We studied both, pure and Fe-promoted H-form zeolites, as sensors and model catalysts at the same time, and found out that weakly bound NH 3 is dominating the proton conductivity of both zeolites in a temperature range below the desorption temperature of NH 3 . When a part of the weakly bound NH 3 is consumed by the SCR reaction, proton conductivity and thus the sensing effect gets dominated by strongly bound NH 3 . This allows applying impedance spectroscopy to assess the degree of NH 3 loading and the state of the SCR conversion process in zeolite catalyst. [ABSTRACT FROM AUTHOR]

Metal(IV) phosphates such as zirconium phosphate (ZrP) are well known proton conductors based on the mobility of protons localized at Brønsted-acid sites. By introduction of mesoporous silica into the interlayer region, these compact materials are transformed into Porous Phosphate Heterostructures (PPH). Here we studied the electrical properties of PPH and show that the proton conductivity is supported by ammonia, which does not occur neither in ZrP nor in the mesoporous silica. This demonstrates that transforming the layer structure of ZrP into a mesoporous hybrid material leads to a new ammonia gas sensing material. This concept might be promising for the development of new gas sensor materials in general. [ABSTRACT FROM AUTHOR]

This report centers on different modern chemical synthesis methods suitable for production with which low-dimensional crystalline structures are attainable in the Ge–Sb–Te material system. The general characteristics of the methods are described first. The special challenges are discussed for the Ge–Sb–Te material system. Growth optimization is studied, and the resulting nanostructures are presented. At last a comparison of the methods is given with respect to research scale vapor transport approach on the one hand and the potential described for future application in technology on the other hand. [ABSTRACT FROM AUTHOR]

Abstract: The dynamic C2H5OH sensitivity of ilmenite-type cobalt titanates volume-doped by 2at% Li, Na, K, Sb, La, Sm, Gd, Ho and Pb was systematically studied with respect to exhaust monitoring. Therefore, the p-type semiconducting CoTiO3 materials were characterized as resistive gas sensors via high-throughput impedance spectroscopy toward 5–200ppm C2H5OH at 300–500°C. The best performing materials were tested further by time-resolved and long-term measurements whereby the CoTiO3 volume-doped with K exhibited an outstanding overall performance. X-ray absorption spectroscopy on this particular material gave evidence that the local structure around Co and Ti remains unaffected by the doping despite of a slight increase in static disorder. Hence, the effect of K doping does not originate from alteration in the metal-to-oxygen interaction as expected from previous findings. [Copyright &y& Elsevier]

Abstract: Gold nanoparticles (GNP) provide many opportunities in imaging, diagnostics, and therapies of nanomedicine. Hence, their biokinetics in the body are prerequisites for specific tailoring of nanomedicinal applications and for a comprehensive risk assessment. We administered 198Au-radio-labelled monodisperse, negatively chargedGNP of five different sizes (1.4, 5, 18, 80, and 200nm) and 2.8nm GNP with opposite surface charges by intravenous injection into rats. After 24h, the biodistribution of the GNP was quantitatively measuredby gamma-spectrometry. The size and surface charge of GNP strongly determine the biodistribution. Most GNP accumulated in the liver increased from 50% of 1.4nm GNP to >99% of 200nm GNP. In contrast, there was little size-dependent accumulation of 18–200nm GNP in most other organs. However, for GNP between 1.4nm and 5nm, the accumulation increased sharply with decreasing size; i.e. a linear increase with the volumetric specific surface area. The differently charged 2.8nm GNP led to significantly different accumulations in several organs. We conclude that the alterations of accumulation in the various organs and tissues, depending on GNP size and surface charge, are mediated by dynamic protein binding and exchange. A better understanding of these mechanisms will improve drug delivery and dose estimates used in risk assessment. [Copyright &y& Elsevier]

Abstract: Background: The healing outcome of long bone fractures is strongly influenced by the mechanical environment. High interfragmentary movement at the fracture site is detrimental to the fracture healing process. Long bone fractures stabilized with thin intramedullary nails commonly used for unreamed intramedullary nailing might be very flexible in shear direction and therefore critical for the fracture healing outcome. The aims of this study were to simulate the shear interfragmentary movement during gait for a human tibia treated with intramedullary nailing and to investigate if this movement could be lowered by implant design modifications. Methods: The shear movement was calculated with a 3D finite element model based on computer tomograph images of a cadaver bone–implant complex of a transverse tibia fracture treated with a Stryker T2 Standard Tibial Nail. This model was validated through in vitro test results under pure shear, axial, bending and torsional loading. Findings: High shear movements of approximately 4mm were calculated during gait. These shear movements could be reduced by approximately 30% either by implant modifications or the use of a 1mm thicker nail. Combining the implant modifications with a 1mm thicker nail, the shear movements could be reduced by 54%. Interpretation: The increase of the fixation stiffness by using an implant material with a high Young''s modulus in combination with an angle–stable nail–screw fixation helps to reduce the shear movement during gait and possibly to lower the risk of a prolonged healing time with unreamed intramedullary nailing. [Copyright &y& Elsevier]

Abstract: The rat is of increasing importance for experimental studies on fracture healing. The healing outcome of long bone fractures is strongly influenced by mechanical factors, such as the interfragmentary movement. This movement depends on the stability of the fracture fixation and the musculoskeletal loads. However, little is known about these loads in rats. The musculoskeletal loads during gait were estimated using an inverse-dynamic musculoskeletal model of the right hindlimb of the rat. This model was based on a micro-CT scan of the lower extremities and an anatomical study using 15 rat cadavers. Kinematics were reconstructed from X-ray movies, taken simultaneously from two perpendicular directions during a gait cycle. The ground reaction forces were taken from the literature. The muscle forces were calculated using an optimization procedure. The internal forces and moments varied over the gait cycle and along the femoral axis. The greatest internal force (up to 7 times bodyweight) acted in the longitudinal direction. The greatest internal moment (up to 13.8 bodyweight times millimeter) acted in the sagittal plane of the femur. The validity of the model was corroborated by comparing the estimated strains caused by the calculated loads on the surface of the femoral mid-shaft with those from the literature. Knowledge of the internal loads in the femur of the rat allows adjustment of the biomechanical properties of fixation devices in fracture healing studies to the desired interfragmentary movement. [Copyright &y& Elsevier]

Background: The healing outcome of long bone fractures is strongly influenced by the interfragmentary movement of the bone fragments. This depends on the fixation stability, the optimum value of which is still not known. The aim of this study was to simulate a patient-specific human healing process using a numerical algorithm and to retrospectively analyse the influence of the fixation stability on the healing time. Methods: The healing simulation was processed as an initial value problem. This was iteratively solved based on two mechanical (invariants of the strain tensor, calculated through a finite element analysis) and five biological state variables (local tissue composition and blood perfusion) using a previously published fuzzy logic algorithm. For validation purposes, the calculated interfragmentary movement was compared to in vivo measurements of this patient. By changing clinically adjustable parameters of the fixation device, the influence of the fixation stability on the healing time was analysed. Finding: The time course showed good agreement of the interfragmentary movement compared with the in vivo measurements. The predicted healing time was strongly influenced by the fixation stability, i.e. by changing the parameters of the fixation device, it was possible to significantly reduce the healing time. Interpretation: The time to heal could be greatly reduced by modification of the fixator design, i.e. increasing the fixation stiffness. When using external fixation devices, this could be achieved by decreasing the free bending length of the pins, using a stiff fixation body and a stiff connection between the pins and the body. [Copyright &y& Elsevier]

Abstract: We report, for the first time, symmetric (versus cluster potential of zero charge) charging of narrowly dispersed monolayer-protected Au145 cluster films in a room temperature ionic liquid. Near-reversible voltammetric features are found, indicating up to nine electrochemically accessible charge states with assigned values between −4 and +5. The zero charge state has a stability range of 276mV, very similar as found in solution-phase voltammetry. All other charge states are more narrowly spaced, indicating a sudden increase in cluster capacitance. We ascribe this effect to an abrupt change in local dielectric constant on insertion of one or more counter ions, following departure from zero charge, with a possible contribution of coupled electron–ion transfer. Our findings open perspectives of potential technological importance involving nanocrystal-based device-like behaviour. [Copyright &y& Elsevier]

Abstract: The self-assembly of ω-ferrocenylalkanethiols (FcCnSH) with different alkyl-spacer lengths on Au(111) substrates has been studied by scanning tunneling microscopy (STM). Upon deposition at room temperature FcCnSH molecules tend to form multilayers, while by thermal treatment monolayer formation, a rearrangement of the molecules and the formation of ordered domains is achieved. The surface structure of the resulting full coverage self-assembled monolayers is resolved with molecular resolution by STM. The ordered monolayer structure of ω-ferrocenylpropanethiol is discussed in comparison with its bulk crystal structure, derived from single crystal X-ray analysis. Based on these results a monolayer structure of ω-ferrocenylalkanethiols with longer alkyl chains closely related to the bulk crystal structure of the shorter alkyl-spacer derivates is suggested. Our results provide detailed insight into the self-assembly of FcCnSH on gold substrates. [Copyright &y& Elsevier]

Abstract: Sulfonated poly(ether ether ketone) (SPEEK)–silica membranes doped with phosphotungstic acid (PWA) are presented. The silica is generated in situ via the water free sol–gel process of polyethoxysiloxane (PEOS), a liquid hyperbranched inorganic polymer of low viscosity. At 100°C and 90% RH the membrane prepared with PEOS (silica content=20wt%) shows two times higher conductivity than the pure SPEEK. The addition of small amounts of PWA (2wt% of the total solid content) introduced in the early stage of membrane preparation brings to a further increase in conductivity (more than three times the pure SPEEK). During membrane formation PWA and the sulfonic acid groups of SPEEK act as catalysts in the conversion of PEOS in silica. Once the membranes are formed, PWA is incorporated in the silica network and acts as proton conductivity enhancer. The correlation between morphology and proton conductivity allows establishing the optimal doping level and preparation procedure. The morphology is studied by transmission electron microscopy (TEM) while the proton conductivity is measured by impedance spectroscopy (IS). The direct methanol fuel cell performance is also investigated. [Copyright &y& Elsevier]

Abstract: We compare the characteristic features obtained in TPD and in impedance measurements on the desorption of ammonia from zeolite H-ZSM-5. We show that the ammonia desorption peaks observed by TPD correspond to characteristic changes in the proton transport mechanism. While at low temperature an almost temperature independent Grotthus-like proton conductivity in the presence of ammonia is observed, the on-set of the low temperature desorption peak in TPD coincides with a change in the transport mechanism to a vehicle-mediated transport of protons. Furthermore, at higher temperature, the desorption of ammonia from the Brønsted acid sites, as indicated by the high temperature peak in TPD, causes again a characteristic change in the temperature dependent conductivity, reflected by a decreasing conductivity with increasing temperature in an intermitted range, which then turns over again to simply activated proton hopping. [Copyright &y& Elsevier]

Abstract: We present a humidity sensor based on H-ZSM-5 type zeolite that is suitable to detect traces of humidity (∼10–110ppmV) under harsh conditions, e.g. reducing atmosphere (H2) and high temperature (up to 600°C). By means of complex impedance spectroscopy (IS) we show that the zeolite sensor responds linearly towards minimal changes in humidity. Therefore this result indicates that the zeolite sensor is capable to detect traces of humidity in processes where high temperatures in a hydrogen environment are required. [Copyright &y& Elsevier]

Abstract: The acid properties of H-ZSM-5 zeolites with different SiO2/Al2O3 ratios (30, 50, 80, 150, 280 and 1000) were examined by means of the temperature programmed desorption of ammonia (NH3-TPD). Different pretreatments together with a comparison of different curve-fitting methods after desorption of ammonia were used to differentiate between different adsorption sites. 27Al-MAS-NMR spectroscopy was applied to distinguish the framework (AlF) from the extra-framework aluminum (AlEF). Both techniques reveal that the concentration of Brønsted acid sites is lower than expected when considering the aluminum content. The strength of the Brønsted acid sites, determined by a theoretical model assuming the free readsorption of ammonia, is found to be in the range of ΔH =129–161kJmol−1 and shows variations in the acid strength to be less than σ =12kJmol−1. [Copyright &y& Elsevier]

Abstract: Trabecular bone fractures heal through intramembraneous ossification. This process differs from diaphyseal fracture healing in that the trabecular marrow provides a rich vascular supply to the healing bone, there is very little callus formation, woven bone forms directly without a cartilage intermediary, and the woven bone is remodelled to form trabecular bone. Previous studies have used numerical methods to simulate diaphyseal fracture healing or bone remodelling, however not trabecular fracture healing, which involves both tissue differentiation and trabecular formation. The objective of this study was to determine if intramembraneous bone formation and remodelling during trabecular bone fracture healing could be simulated using the same mechanobiological principles as those proposed for diaphyseal fracture healing. Using finite element analysis and the fuzzy logic for diaphyseal healing, the model simulated formation of woven bone in the fracture gap and subsequent remodelling of the bone to form trabecular bone. We also demonstrated that the trabecular structure is dependent on the applied loading conditions. A single model that can simulate bone healing and remodelling may prove to be a useful tool in predicting musculoskeletal tissue differentiation in different vascular and mechanical environments. [Copyright &y& Elsevier]

The complex interplay of dust sedimentation, pedogenesis, and erosion/reworking in the formation of loess-paleosol sequences (LPS) challenges paleoenvironmental proxies. Here we show that color and grain size are essential parameters characterizing loess profiles and support robust stratigraphies as a basis for reconstructions in the context of local geo-ecological and large-scale paleoclimatic evolution. Detailed paleoenvironmental records from the period since the arrival of anatomically modern humans to the last glacial maximum are scarce in the Alpine surroundings. The c. 7.5 m thick LPS Krems-Wachtberg, NE Austria, known for its well-preserved Upper Paleolithic context at a depth of 5.5 m, formed between 40 and 20 ka BP by quasi-continuous dust-sedimentation, interrupted by phases of incipient pedogenesis and local reworking. The new KW2015 composite is based on three sections studied and sampled at 2.5 cm resolution. Color and grain size data support a robust stratigraphy for reconstructions of the pedosedimentary evolution. The marked transition from oxidized to reduced paleosols of KW2015 around 34–35 ka corresponds to the Middle-to Upper Pleniglacial transition as part of a general cooling trend from marine isotope stage (MIS) 3 to 2, intensely modulated by millennial-scale climatic fluctuations as recorded in the Greenland ice core data. The distinct response of KW2015 to these trends highlights that reconstructing LPS evolution based on a robust stratigraphy is a prerequisite to paleoenvironmental proxy interpretation. • 7.2 m thick loess studied at the Upper Paleolithic Krems-Wachtberg site (KW2015). • Detailed KW2015 stratigraphy supported by high-resolution color and grain size data. • Complex pedosedimentary evolution challenges standard paleoenvironmental proxies. • Detailed Middle- to Upper Pleniglacial paleoenvironmental record in the NE Alpine forelands. • Distinct local response of KW2015 to large-scale paleoclimatic shifts (MIS 3/2 transition). [ABSTRACT FROM AUTHOR]

Reduction of harmful nitrogen oxides (NO x) from diesel engine exhausts is one of the key challenges in environmental protection, and can be achieved by NH 3 -assisted selective catalytic reduction (NH 3 -SCR) using copper-exchanged chabazite zeolites (i.e. Cu-CHA, including Cu-SSZ-13 and Cu-SAPO-34) as catalysts. Understanding the redox chemistry of Cu-CHA in NH 3 -SCR catalysis is crucial for further improving the NO x reduction efficiency. Here, a series of Cu-SSZ-13 catalysts with different Cu ion exchange levels were prepared, thoroughly characterized by different techniques such as X-ray diffraction, diffuse reflectance ultraviolet–visible spectroscopy and temperature-programmed desorption using NH 3 as a probe molecule, etc., and tested in NH 3 -SCR reactions under steady-state conditions. In situ studies by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), supplemented with density-functional theory calculations, provided solid evidence for the formation of ammonium ion (NH 4 +) intermediates resulting from the reduction of Cu2+ to Cu+ by co-adsorbed NH 3 and NO molecules on Cu-SSZ-13. Catalytic relevance of the NH 4 + intermediates, as demonstrated by an increase of NO conversion over Cu-SSZ-13 pre-treated in NH 3 /NO atmosphere, can be attributed to the formation of closely coupled Cu+/NH 4 + pairs promoting the Cu+ re-oxidation and, consequently, the overall NH 3 -SCR process. This study thus paves a new route for improving the NH 3 -SCR efficiency over Cu-CHA zeolite catalyst. Image 1 • The relative content of NH 4 + intermediates was determined by in situ DRIFTS. • Cu redox cycle in NH 3 -SCR is closely related to the formation of NH 4 + intermediates. • The catalytic relevance of NH 4 + intermediates was elaborated. [ABSTRACT FROM AUTHOR]