Zeolite LTA deposition on silicon wafer

The deposition of zeolite LTA layer on silicon wafer, from homogeneous synthesis systems, trough the seeding method, has been systematically investigated and high quality, oriented zeolite films are obtained. Basically the seeding method consists in various steps. In the first step the support surface is modified in order to promote the adhesion of pre-synthesized colloidal zeolite seeds, oppositely charged. The seeded support is then hydrothermally treated in the same synthesis solution to allow the growth of zeolite seeds into a dense film. In this work it was shown that the ageing of the synthesis solution before zeolite crystallization process, sensibly affects both size, amount and formation kinetics of the zeolite LTA crystals deposited on the seeded silicon surface.     

Evaluating Thesaurus Alignments for Semantic Interoperability in the Library Domain

Thesaurus alignments play an important role in realizing efficient access to heterogeneous cultural-heritage data. Current technology, however, provides only limited value for such access because it fails to bridge the gap between theoretical study and practical application requirements. This article explores common real-world library problems and identifies solutions that focus on the application-embedded study, development, and evaluation of matching technology.     

Electrochemical behaviour of polyacrylic acid coated gold electrodes: An application to remove heavy metal ions from wastewater

An efficient and low cost preparation method (Diazonium-Induced Anchoring Process) to graft polyacrylic acid (PAA) on the gold substrate has been reported. IR, XPS and AFM techniques were used to characterize the obtained polymer film. The interfacial electrochemistry of the PAA coated gold electrodes was studied by means of impedance spectroscopy and cyclic voltammetry transition techniques. The ability of PAA-grafted onto a gold electrode to reversibly bind or release metal ions was confirmed. As a broad-range chelating material, PAA is able to capture several heavy metal ions at low concentration. The release of those metal ions from the grafted PAA film was obtained under electro-induced-acidification by applying an anodic potential at the electrode to promote a localized water electrolysis. Application of electrochemical-pH-switchable PAA films can be considered within the field of heavy metal waste treatments.     

SIMONE: a realistic neural network simulator to reproduce MEA-based recordings.

Contemporary multielectrode arrays (MEAs) used to record extracellular activity from neural tissues can deliver data at rates on the order of 100 Mbps. Such rates require efficient data compression and/or preprocessing algorithms implemented on an application specific integrated circuit (ASIC) close to the MEA. We present SIMONE (Statistical sIMulation Of Neuronal networks Engine), a versatile simulation tool whose parameters can be either fixed or defined by a probability distribution. We validated our tool by simulating data recorded from the first olfactory relay of an insect. Different key aspects make this tool suitable for testing the robustness and accuracy of neural signal processing algorithms (such as the detection, alignment, and classification of spikes). For instance, most of the parameters can be defined by a probabilistic distribution, then tens of simulations may be obtained from the same scenario. This is especially useful when validating the robustness of the processing algorithm. Moreover, the number of active cells and the exact firing activity of each one of them is perfectly known, which provides an easy way to test accuracy.     

Experimentally Determined Phase Diagram for the Barium Sulfide-Copper(I) Sulfide System Above 873 K (600 °C)

The phase diagram of the barium sulfide-copper(I) sulfide system was investigated above 873 K (600 °C) using a custom-built differential thermal analysis (DTA) apparatus. The melting point of barium sulfide was determined utilizing a floating zone furnace. Four new compounds, Ba₂Cu₁₄S₉, Ba₂Cu₂S₃, Ba₅Cu₄S₇, and Ba₉Cu₂S₁₀, were identified through quench experiments analyzed with wavelength dispersive X-ray spectroscopy (WDS) and energy dispersive X-ray analysis (EDS). A miscibility gap was observed between 72 and 92 mol pct BaS using both DTA experiments and in situ melts observation in a floating zone furnace. A monotectic was observed at 94.5 mol pct BaS and 1288 K (1015 °C).     

Glycerol steam reforming over Ru-Mg-Al hydrotalcite-derived mixed oxides: Role of the preparation method in catalytic activity

Ru-Mg-Al hydrotalcite-derived mixed oxides were synthesized using two preparation methods. The grafted catalyst was prepared by co-precipitation of the Ru/Mg/Al precursors at a constant pH. The impregnated catalyst was prepared by wet-impregnation of a calcined Mg-Al support with the Ru precursor (Ru(NO) (NO₃)₃). Both catalysts were calcined at 600 °C and characterized by X-ray diffraction, CO₂- temperature programmed desorption and H₂-temperature programmed reduction techniques. Catalytic activities were compared in the glycerol steam reforming reaction (400–700 °C, WGFR 9:1, flow rate: 0.075 ml/min) followed by a short-term stability test at 600 °C. The impregnated catalyst demonstrated a superior activity beyond 600 °C. This difference in activity was attributed to the easier accessibility of the active phase resulting from the preparation method. Short-term stability tests revealed deactivation of both catalysts as a result of coke formation.     

Conceptual design of Tritium Extraction System for the European HCPB Test Blanket Module

The HCPB (Helium Cooled Pebble Bed) Test Blanket Module (TBM), developed in EU to be tested in ITER, adopts a ceramic containing lithium as breeder material, beryllium as neutron multiplier and helium at 80 bar as primary coolant.In HCPB-TBM the main function of Tritium Extraction System (TES) is to extract tritium from the breeder by gas purging, to remove it from the purge gas and to route it to the ITER Tritium Plant for the final tritium processing.In this paper, starting from a revision of the so far reference process considered for HCPB-TES and considering a new modeling activity aimed to evaluate tritium concentration in purge gas, an updated conceptual design of TES is reported.     

Design of a multipurpose laboratory scale apparatus for the investigation of hydrogen isotopes in PbLi and permeation technologies

The knowledge of the tritium transport parameters in lead lithium is fundamental for the design of the HCLL (helium cooled lead lithium) blanket. In fact, the inventory of tritium in fusion reactors blankets and the permeation of tritium into the blanket coolant, with the consequent leaks toward the environment, are strongly depending on its solubility and diffusivity in the lead alloy PbLi. Several experiments, devoted to investigate the function linking the tritium solubilised in lead lithium with the corresponding tritium partial pressure at equilibrium, were carried out in the past, but significant uncertainties still remain.A detailed analysis of the past experimental works is carried out in this paper with the aim to investigate the main problems occurred in the facilities used to measure the tritium solubility in PbLi that caused such a big spread in the achieved results. On the basis of this analysis, a new a multipurpose laboratory scale apparatus has been designed. The apparatus is able to measure the tritium solubility and diffusivity in PbLi in the range of temperature 300–550 °C and it will be operated with hydrogen partial pressure in the range 10²–10⁴ Pa. The facility can work with desorption and absorption technique.Moreover, the apparatus has been designed to allow the testing of H/D concentration sensors in Pb–15.7Li in operative conditions relevant to the HCLL–TBM and the characterisation of hydrogen permeation barrier.     

Rate-dependent tensile behavior of high performance fiber reinforced cementitious composites

High Performance Fiber Reinforced Cementitious Composites (HPFRCC) show strain hardening behavior accompanied with multiple micro-cracks under static tension. The high ductility and load carrying capacity resulting from their strain hardening behavior is expected to increase the resisting capacity of structures subjected to extreme loading situations, e.g., earthquake, impact or blast. However, the promise of HPFRCCs for dynamic loading applications stems from their observed good response under static loading. In fact, very little research has been conducted to investigate if their good static response translates into improved dynamic response and damage tolerance. This experimental study investigates the tensile behavior of HPFRCC using High strength steel fibers (High strength hooked fiber and twisted fiber) under various strain rates ranging from static to seismic rates. The test results indicate that the tensile behavior of HPFRCC using twisted fiber shows rate sensitivity while that using hooked fiber shows no rate sensitivity. The results also show that rate sensitivity in twisted fibers is dependent upon both fiber volume fraction and matrix strength, which influences the interface bond properties.