Low temperature and cost-effective growth of vertically aligned carbon nanofibers using spin-coated polymer-stabilized palladium nanocatalysts

We describe a fast and cost-effective process for the growth of carbon nanofibers (CNFs) at a temperature compatible with complementary metal oxide semiconductor technology, using highly stable polymer–Pd nanohybrid colloidal solutions of palladium catalyst nanoparticles (NPs). Two polymer–Pd nanohybrids, namely poly(lauryl methacrylate)-block-poly((2-acetoacetoxy)ethyl methacrylate)/Pd (LauMA_x-b-AEMA_y/Pd) and polyvinylpyrrolidone/Pd were prepared in organic solvents and spin-coated onto silicon substrates. Subsequently, vertically aligned CNFs were grown on these NPs by plasma enhanced chemical vapor deposition at different temperatures. The electrical properties of the grown CNFs were evaluated using an electrochemical method, commonly used for the characterization of supercapacitors. The results show that the polymer–Pd nanohybrid solutions offer the optimum size range of palladium catalyst NPs enabling the growth of CNFs at temperatures as low as 350 °C. Furthermore, the CNFs grown at such a low temperature are vertically aligned similar to the CNFs grown at 550 °C. Finally the capacitive behavior of these CNFs was similar to that of the CNFs grown at high temperature assuring the same electrical properties thus enabling their usage in different applications such as on-chip capacitors, interconnects, thermal heat sink and energy storage solutions.     

Reconstruction procedure for 3D micro X-ray absorption fine structure

A new approach for chemical speciation in stratified systems using 3D Micro-XAFS spectroscopy is developed by combining 3D Micro X-ray Fluorescence Spectroscopy (3D Micro-XRF) and conventional X-ray Absorption Fine Structure Spectroscopy (XAFS). A prominent field of application is stratified materials within which depth-resolved chemical speciation is required. Measurements are collected in fluorescence mode which in general lead to distorted spectra due to absorption effects. Developing a reliable reconstruction algorithm for obtaining undistorted spectra for superficial and in-depth layers is proposed and validated. The developed algorithm calculates the attenuation coefficients of the analyte for the successive layers facilitating a new spectroscopic tool for three-dimensionally resolved nondestructive chemical speciation.     

Dose-dependent immunomodulatory effects of 10-hydroxy-2-decenoic acid on human monocyte-derived dendritic cells

The effect of 10-hydroxy-2-decenoic acid (10-HDA), the unique component of royal jelly, on maturation and functions of human monocyte-derived dendritic cells (MoDCs) in culture was investigated. It has been shown that 10-HDA, at concentrations higher than 500 μM, induces apoptosis of MoDCs. A lower dose (50 μM) stimulated T helper (Th)1 and down-regulated Th2 immune responses, as judged by the levels of interferon-gamma (IFN-γ) and interleukin (IL)-4, respectively, in supernatants of 10-HDA-treated MoDCs cultivated with allogeneic CD4⁺T cells. In contrast, a higher dose of 10-HDA (500 μM), although non-cytotoxic, inhibited maturation of lipopolysaccharide (LPS)-stimulated MoDCs. Such treated MoDCs produced lower levels of IL-12, IL-18 and tumour necrosis factor-alpha (TNF-α) and down-regulated both Th1 and Th2 immune responses. In conclusion, our results suggest that 10-HDA exerts different activity on human MoDCs, depending on applied concentrations, which is important when considering its therapeutic immunomodulatory property.     

Adsorption and release of gemcitabine hydrochloride and oxaliplatin by hydroxyapatite

The aim of this study was to investigate the adsorption and the release profile of two anticancer drugs, gemcitabine hydrochloride (dFdU.HCl) and oxaliplatin (DACH-Pt), from hydroxyapatite (HAP) in order to evaluate HAP as local drug delivery system (DDS). Various initial concentrations of drug aqueous solutions were used in order to determine the maximum adsorption capacity of HAP after 48 h shaking. The maximum adsorption capacity of dFdU.HCl (400 mg/g HAP) was achieved after 40 h while the maximum adsorption capacity of DACH-Pt (49.1 mg/g HAP) was accomplished after 20 h. Adsorption processes for both drugs were found to fit the Freundlich equation. The release processes were studied by soaking the samples of loaded HAP in simulation body fluids (SBF). After only 1 h 65% of dFdU.HCl was released while the release of DACH-Pt from the HAP was more gradual since 55% of DACH-Pt was released in the first 24 h. Finally, in an attempt to understand the molecular basis of the drug action, the chemical interactions involved in the complex processes of drug delivery were studied theoretically.     

Anamorphic Experiences in 3D Space: Shadows,Projections and Other Optical Illusions

The paper presents recent research on the reconstruction of Anamorphic effects and other optical illusions, shadows and projections, with the use of CAD systems. The first part of the paper is a bibliographical overview about the appearance of optical illusions in art, ranging from the work of Niceron to the extravagant sculptures of contemporary artists such as Markus Raetz. The second part of the paper reports on an educational approach that introduces anamorphic geometries into the teaching of digital methods of representation at Graz University of Technology. There is an overview of the experiments and methodology for constructing optical illusions in a CAD environment as well as examples drawn from student projects. The paper concludes with some observations and remarks relating to the aforementioned educational experience.     

Interrupted by Your Pupil: An Interruption Management System Based on Pupil Dilation

Interruptions are prevalent in everyday life and can be very disruptive. An important factor that affects the level of disruptiveness is the timing of the interruption: Interruptions at low-workload moments are known to be less disruptive than interruptions at high-workload moments. In this study, we developed a task-independent interruption management system (IMS) that interrupts users at low-workload moments in order to minimize the disruptiveness of interruptions. The IMS identifies low-workload moments in real time by measuring users’ pupil dilation, which is a well-known indicator of workload. Using an experimental setup we showed that the IMS succeeded in finding the optimal moments for interruptions and marginally improved performance. Because our IMS is task-independent—it does not require a task analysis—it can be broadly applied.     

Modeling of cable-moored floating breakwaters connected with hinges

In the present paper, the overall performance of a cable-moored array of floating breakwaters connected by hinges is investigated under the action of monochromatic linear waves in the frequency domain. The performance is defined here as: (i) demonstration of acceptable levels of both response of the array and its effectiveness and (ii) non-failure of the mooring lines. The numerical analysis of the array is based on a 3D hydrodynamic formulation of the floating body coupled with the static and dynamic analyses of the mooring lines. The motions of the array of floating breakwaters associated with the hinge vertical translations are considered in the hydrodynamic analysis with the implementation of appropriate generalized modes. The stiffness and damping coefficients caused by the mooring lines in both rigid and generalized degrees of freedom are derived here in the general form. A rigorous parametric study is carried out in order to investigate the effect of different configurations (number of hinge joints and number of mooring lines) on the performance of the cable-moored array of floating breakwaters. Moreover, the performance of the various configurations of cable-moored floating breakwaters connected by hinges examined is compared with the performance of a single cable-moored floating breakwater with no hinges. It is found that the number of hinge joints and mooring lines have a direct effect on the performance of the cable-moored array of floating breakwaters.     

3D micro-XRF for cultural heritage objects: new analysis strategies for the investigation of the Dead Sea Scrolls

A combination of 3D micro X-ray fluorescence spectroscopy (3D micro-XRF) and micro-XRF was utilized for the investigation of a small collection of highly heterogeneous, partly degraded Dead Sea Scroll parchment samples from known excavation sites. The quantitative combination of the two techniques proves to be suitable for the identification of reliable marker elements which may be used for classification and provenance studies. With 3D micro-XRF, the three-dimensional nature, i.e. the depth-resolved elemental composition as well as density variations, of the samples was investigated and bromine could be identified as a suitable marker element. It is shown through a comparison of quantitative and semiquantitative values for the bromine content derived using both techniques that, for elements which are homogeneously distributed in the sample matrix, quantification with micro-XRF using a one-layer model is feasible. Thus, the possibility for routine provenance studies using portable micro-XRF instrumentation on a vast amount of samples, even on site, is obtained through this work.