Abstract: An aptamer-based electrochemical sensor, wherein said aptamer is covalently bonded to or chemisorbed on an electrode, said aptamer forming a robust complex with a target molecule and is encapsulated by a gelatin B matrix; a method of manufacturing an aptamer-based electrochemical sensor for determining a concentration of a target molecule comprising the steps of: selecting an aptamer to form a robust complex with a target molecule using the SELEX procedure; synthesizing said aptamer; adsorbing said aptamer on or covalently coupling said aptamer with an electrode; and providing a gelatin B matrix for said aptamer on said electrode thereby realising said aptamer-based potentiometric or amperometric sensor; and the use of the aptamer-based electrochemical sensor produced according to the above method for the electrochemical determination of a concentration of 15 the target molecule.

Abstract: Historical glass, especially medieval glass, can undergo weathering under the influence of time and environmental conditions. The aim of this investigation was to better understand the processes involved in this natural degradation process by studying artificially altered glass samples prepared for the use of evaluation of conservation methods. Non-durable glass sensors produced by the Fraunhofer Institute (type M1.0) were used as a starting material for artificial alteration. These were immersed in acidic (pH = 0, 2, 4) and neutral solutions (1 h – 8 h). In a second stage the glass samples were immersed in a 0.5 M MnCl2 solution (24 h, 48 h and 72 h), allowing intrusion of Mn from the solution into the gel layer. The samples were characterized at different stages with reflectance FTIR spectroscopy, mu XRF mapping and mu XANES. All measurements were carried out at ESRF, beamline ID21. Reflectance FTIR spectroscopy measurements were performed in the 800 4000 cm(-1) range. Cluster analysis of the resulting maps evidenced the rapid growth of the gel layer in strong acidic conditions. The average spectra for each cluster feature show for the original glass a strong Si-O- stretching band between 900 and 1000 cm(-1), whereas the gel layer could be identified by the increasing Si-O-Si bands around 1100 and 1250 cm(-1). mu XRF maps were recorded at different stages of the experiment at energies around the Mn-K edge (6.539 keV) and with a step size of 2 by 2 m. These confirm the leaching of K+ and Ca+2 from the glass and the intrusion of Mn from the solution. Mn was found throughout the entire gel layer, but with a concentration gradient peaking at the surface. XANES point measurements were recorded at various points where Mn was present. No spatial variation was found, but linear combination fitting of the spectra with various Mn reference compounds indicated that Mn2+Mn23+O4 is the main Mn compound in the gel layer, as was hypothesised by Watkinson et al. The standard corroded glass samples studied here can be used for the evaluation of conservation treatments in follow-up experiments. (C) 2013 The Authors. Published by Elsevier B.V. Selection and peer-review under responsibility of the IA-CS (Italian Association of Conservation Scientists) and University of Antwerp

Abstract: In the present contribution several advanced electron microscopy techniques are employed in order to describe chemical and structural features of the nano- and microstructure of a Ni45.5Ti45.5Nb9 alloy. A line-up of Nb-rich nano-precipitates is found in the Ni-Ti-rich austenite of as-cast material. Concentration changes of the matrix after annealing are correlated with changes in the transformation temperatures. The formation of rows and plates of larger Nb-rich precipitates and particles is described. The interaction of a twinned martensite plate with a Nb-rich nano-precipitate is discussed and the substitution of Nb atoms on the Ti-sublattice in the matrix is confirmed.

Abstract: We study the quantum Hall effect (QHE) in bilayer graphene using the Kubo-Greenwood formula. At zero temperature the Hall conductivity sigma(yx) is given by sigma(yx) – 4(N + 1)e(2)/h with N the index of the highest occupied Landau level (LL). Including the dispersion of the LLs and their width, due to e. g. scattering by impurities, produces the plateau of the n = 0 LL in agreement with experimental results on doped samples and similar theoretical results on single-layer graphene plateaus widen with impurity concentration. Further, the evaluated resistivity rho(xx) exhibits a strong, oscillatory dependence on the electron concentration. Explicit results are obtained for delta-function impurities.

Abstract: Dalle de verre windows, created from 19301940 onwards, consist of glass pieces with a thickness of approximately 2 to 5 cm, set in a matrix of (reinforced) concrete. Besides the degradation of the concrete, the windows suffer mainly from a complex three-dimensional form of cracking of the glass elements. The cracks need to be consolidated in order to ensure stability and improve transparency. A selection of possible adhesives was evaluated: Araldite® 2020, Hxtal NYL-1, Fynebond, Paraloid® B-72, LV740, A18 and OR-G®. An attempt has been made to objectively compare these adhesives using a bench-marking system. None of the adhesives appears to be suitable for in situ application; sufficient penetration of the adhesives can only be realised with the help of vacuum techniques.

Abstract: In 2008, Museum M in Louvain (Flanders, Belgium) acquired a panel depicting The Anointing at Bethany that is believed once to have adorned the citys former Charterhouse. The panel required conservation treatment, which was preceded by a thorough art-historical and technical examination. It emerged that comparable panels are kept at the Metropolitan Museum of Art and the Riverside Church in New York. Chemical analyses show most of the glass in the panel to have a typical 16th century high-limelow-alkali composition. The conservation treatment was based on the evaluation of these findings and focused very strongly on enhancing the aesthetic balance for an improved reading of the panel.