The Influence of the Nature of Anions on the Adhesion Durability of Bitumen–Anionite Protective Systems

Protection of Metals and Physical Chemistry of Surfaces - The influence of AV-17-8, a strong basic anion-exchange resin introduced in various ionic forms as an active filler on the adhesive...     

Experience in the Development and Production of Thermal-Neutron Detectors at the IBR-2 DSC (Review)

Instruments and Experimental Techniques - One of the most important activities of the IBR-2 DSC is the development of detector technologies, which will be used as a basis in designing detectors for...     

Mechanism of anodic oxidation of molybdenum in nearly-neutral electrolytes studied by electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy

Anodic oxidation of molybdenum in weakly acidic, nearly neutral and weakly alkaline electrolytes was studied by voltammetric and electrochemical impedance spectroscopic measurements in a wide potential and pH range. Current vs. potential curves were found to exhibit two pseudo-Tafel regions suggesting two parallel pathways of the dissolution process. Electrochemical impedance spectra indicated the presence of at least two reaction intermediates. X-ray photoelectron spectroscopic (XPS) results pointed to the formation of an oxide containing Mo(IV), Mo(V) and Mo(VI), the exact ratio between different valence states depending on potential and pH of the solution. A physico-chemical model of the processes is proposed and a set of kinetic equations for the steady-state current vs. potential curve and the impedance response are derived. The model is found to reproduce quantitatively the current vs. potential curves and impedance spectra at a range of potentials and pH and to agree qualitatively with the XPS results. Subject to further improvement, the model could serve as a starting point for the optimization of the electrochemical fabrication of functional molybdenum oxide coatings.     

Medical hydrogels based on bioactive compounds. Synthesis,properties, and possible application for preparing bactericidal materials

Several physicochemical analytical methods were used to study aqueous solutions and hydrogels based on L-cysteine and silver nitrate. It was found that anions played a decisive role in forming the threedimensional gel-network in dilute silver-cysteine solutions. The ability to use silver-cysteine solutions and hydrogels to prepare bactericidal fibers and fabrics was examined.     

Brown Dwarf: A fully-distributed, fault-tolerant data warehousing system

In this paper we present the Brown Dwarf, a distributed data analytics system designed to efficiently store, query and update multidimensional data over commodity network nodes, without the use of any proprietary tool. Brown Dwarf distributes a centralized indexing structure among peers on-the-fly, reducing cube creation and querying times by enforcing parallelization. Analytical queries are naturally performed on-line through cooperating nodes that form an unstructured Peer-to-Peer overlay. Updates are also performed on-line, eliminating the usually costly over-night process. Moreover, the system employs an adaptive replication scheme that adjusts to the workload skew as well as the network churn by expanding or shrinking the units of the distributed data structure. Our system has been thoroughly evaluated on an actual testbed: it manages to accelerate cube creation up and querying up to several tens of times compared to the centralized solution by exploiting the capabilities of the available network nodes working in parallel. It also manages to quickly adapt even after sudden bursts in load and remains unaffected with a considerable fraction of frequent node failures. These advantages are even more apparent for dense and skewed data cubes and workloads.     

Polyaniline–water interactions: A theoretical investigation with the polarisable continuum model

The simulations of emeraldine hydrochloride tetramers were performed for the first time in implicit water solvent using the polarisable continuum model (PCM) with the density functional theory (DFT) method. This approach should be more appropriate for the study of the conducting form of polyaniline as all known processes of synthesis and further transformations take place in polar medium. Our results confirm this hypothesis and clearly indicate that the geometry and electronic structure of the emeraldine salt depend on the dielectric properties of the medium. In polar environment the protons are bound tighter to the chains compared to vacuum and this leads to stronger impact of the dopant on the structural parameters of PANI. As a consequence, the density distribution in the emeraldine hydrochloride obtained by PCM is more realistic compared to vacuum estimates. The stability in polar medium of two possible salt configurations with respect to counterions position is assessed. Each configuration is simulated in singlet and triplet state (bipolaron and polaron). The results show that at the tetramer level the bipolaron form is always preferred in accordance to available experimental results.     

Theoretical and methodological implications of designing and implementing multiuser location-based games

Multiuser location-aware applications present a new form of mediated communication that takes place within a digital as well as a physical spatial context. The inherently hybrid character of locative media use necessitates that the designers of such applications take into account the way communication and social interaction is influenced by contextual elements. In this paper, an investigation into the communicational and social practices of users who participate in a location-based game is presented, with an emphasis on group formation and dynamics, interpersonal communication, and experienced sense of immersion. This investigation employs a methodological approach that is reliant on both qualitative and quantitative data analysis. A series of this user experience study’s results are presented and discussed.