A correlation for heat of vaporization of pure compounds

Twenty-seven selected equations were tested on 162 compounds with 1958 calorimetric data for their abilities to reflect the temperature influence on the heat of vaporization of pure compounds. A new equation is recommended (overall percent deviation 0.27% and percent deviation 0.59% above 0.9T _r ).     

Calcium hydrosilicate as a base for producing thermal insulation products

We have conducted research on the process for producing thermal insulation materials using calcium silicates with the addition of glass fibres. These materials have excellent refractoriness, heat resistance, mechanical strength and dimensional stability and are suitable for refractory coatings, as heat insulators, and as a lagging product.

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Resume Nous avons mené une recherche sur le processus de fabrication de matériaux d’isolation avec des silicates de calcium renforcés de fibres de verre. Ces isolants présentent d’excelllentes résistances à la chaleur et au feu, aussi bien que de bonnes résistance mécanique et stabilité dimensionelle, et se prêtent donc à la confection de revêtements réfractaires, d’isolants thermiques et de calorifuges.

     

Distribution of titanium and aluminium in sintered mullite

The distribution of TiO₂ and Al₂O₃ in mullite and the glassy phase of samples obtained by sintering kaolin and Al₂O₃ with O to 3 wt% TiO₂ has been studied. Quantitative phase analysis was performed by means of X-ray diffraction and by successive dissolution of the glassy phase and mullite in HF. The microstructure and microanalyses of the samples were determined using scanning electron microscopy and by analytical electron microscopy. With samples containing >1 wt% TiO₂, not only two morphologically and compositionally different mullites have been determined (the large prismatic mullites and the small needle-shaped ones, embedded into the glassy matrix) but also rutile in the form of needle-shaped crystals embedded in the glassy matrix. In addition on the surface of prismatic mullites, an exsolution of the phase enriched in titanium and iron has been detected. However, the formation of tialite, Al₂TiO₅, has not been proved either by X-ray diffraction or by analytical electron microscopy. Using energy dispersive X-ray analysis a greater Al/Si ratio has been determined for needle-shaped mullites than for prismatic ones. Prismatic mullites have constant Al₂O₃ values, not dependent on the sintering temperature and on TiO₂ added. The solubility of TiO₂ in prismatic mullites is due to the decrease in SiO₂.     

Compositional software verification based on game semantics and process algebra

We present an approach to software model checking based on game semantics and the CSP process algebra. Open program fragments (i.e. terms-in-context) are compositionally modelled as CSP processes which represent their game semantics. This translation is performed by a prototype compiler. Observational equivalence and regular properties are checked by traces refinement using the FDR tool. We also present theorems for parameterised verification of polymorphic terms and properties. The effectiveness of the approach is evaluated on several examples. We acknowledge support by the EPSRC (GR/S52759/01). The second author was also supported by the Intel Corporation, and is also affiliated to the Mathematical Institute, Serbian Academy of Sciences and Arts, Belgrade     

An approach to developing complex database schemas using form types

In this paper we consider an approach to developing complex database schemas. Apart from the theoretical model of the approach, we also developed a CASE tool named Integrated Information Systems*Case, R.6.2 (IIS*Case) that supports the practical application of the approach. In this paper the basis of our approach to the design and integration of database schemas and ways of using IIS*Case is outlined. The main features of a new version of IIS*Case, developed in Java, are described. IIS*Case is based on the concept of ‘form type’ and supports the conceptual modelling of a database schema, generating subschemas and integrating them into a relational database schema in 3NF. IIS*Case provides an intelligent support for complex and highly formalized design and programming tasks. Having an advanced knowledge of information systems and database design is not a compulsory prerequisite for using IIS*Case. IIS*Case is based on a methodology of gradual integration of independently designed subschemas into a database schema. The process of independent subschema design may lead to collisions in expressing real‐world constraints. IIS*Case uses specialized algorithms for checking the consistency of constraints embedded in a database schema and its subschemas. This paper briefly outlines the application of the process of detecting collisions, and actions the designer may take to resolve them. Copyright © 2007 John Wiley & Sons, Ltd.     

The mechanism of formation of a surface film of silver on a platinum electrode in galvanostatic deposition

A mechanism for the growth of thin metal films on inert substrates in galvanostatic metal deposition is proposed. Qualitative agreement between theoretical and experimental results was obtained.     

Backstepping in Infinite Dimension for a Class of Parabolic Distributed Parameter Systems

 In this paper a family of stabilizing boundary feedback control laws for a class of linear parabolic PDEs motivated by engineering applications is presented. The design procedure presented here can handle systems with an arbitrary finite number of open-loop unstable eigenvalues and is not restricted to a particular type of boundary actuation. Stabilization is achieved through the design of coordinate transformations that have the form of recursive relationships. The fundamental difficulty of such transformations is that the recursion has an infinite number of iterations. The problem of feedback gains growing unbounded as the grid becomes infinitely fine is resolved by a proper choice of the target system to which the original system is transformed. We show how to design coordinate transformations such that they are sufficiently regular (not continuous but L _∞). We then establish closed-loop stability, regularity of control, and regularity of solutions of the PDE. The result is accompanied by a simulation study for a linearization of a tubular chemical reactor around an unstable steady state. Date received: June 22, 2001. Date revised: January 17, 2002. RID="*" ID="*"This work was supported by grants from AFOSR, ONR, and NSF.     

Amorphous alloys resistant to corrosion in artificial saliva solution

The tailoring of new corrosion-resistant alloys with specific properties has recently been performed mostly by the sputter deposition technique. The aim of this work was to investigate corrosion resistance of aluminum–tungsten (Al–W) amorphous alloys in artificial saliva solution, pH=5.5, based on the electrochemical methods of cyclic voltammetry and linear polarization. Thin alloy films were prepared on a sapphire substrate by magnetron codeposition. Completely amorphous films were obtained in the Al₈₀W₂₀–Al₆₇W₃₃ composition range. Amorphous Al–W alloys exhibit very high corrosion resistance due to their homogeneous single-phase nature. The passive films spontaneously formed at their surface are uniform with characteristics of an insulator film and prevent corrosion progression in the bulk in a very demanding oral environment. The mechanism of increasing resistivity of Al–W alloys to pitting corrosion and generalized corrosion has been discussed in the view of increasing tungsten content in the alloy. Considering these exceptional corrosion properties and microhardness which falls in the range 7.5±1.6 Pa, Al–W alloys represent promising materials for dental applications.     

Biology of TiO2-oligonucleotide nanocomposites

Emerging areas of nanotechnology hold the promise of overcoming the limitations of existing technologies for intracellular manipulation. These new developments provide approaches for the creation of chemical-biological hybrid nanocomposites that can be introduced into cells and subsequently used to initiate intracellular processes or biochemical reactions. Such nanocomposites would advance medical biotechnology, just as they are improving microarray technology and imaging in biology and medicine, and introducing new possibilities in chemistry and material sciences. Here we describe the behaviour of 45-A nanoparticles of titanium dioxide semiconductor combined with oligonucleotide DNA into nanocomposites in vivo and in vitro. These nanocomposites not only retain the intrinsic photocatalytic capacity of TiO2 and the bioactivity of the oligonucleotide DNA (covalently attached to the TiO2 nanoparticle), but also possess the chemically and biologically unique new property of a light-inducible nucleic acid endonuclease, which could become a new tool for gene therapy.     

Integration of electrokinetic-based multidimensional separation/concentration platform with electrospray ionization-Fourier transform ion cyclotron resonance-mass spectrometry for proteome analysis of Shewanella oneidensis

This work focuses on the development of a multidimensional electrokinetic-based separation/concentration platform coupled with electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) for achieving the high resolution and ultrasensitive analysis of complex protein/peptide mixtures. A microdialysis junction is employed as the interface for on-line combination of capillary isoelectric focusing (CIEF) with transient capillary isotachophoresis/zone electrophoresis (CITP/CZE) in an integrated platform. Besides the excellent resolving power afforded by both CIEF and CZE separations, the electrokinetic focusing/stacking effects of CIEF and CITP greatly enhance the dynamic range and detection sensitivity of MS for protein identification. The constructed multidimensional separation/concentration platform is demonstrated for the analysis of Shewanella oneidensis proteome, which has considerable implications toward the bioremediation of environmental pollutants. The electrokinetic-based platform offers the overall peak capacity comparable to those obtained using multidimensional chromatography systems, but with a much shorter run time and no need for column regeneration. Most importantly, a total of 1174 unique proteins, corresponding to 26.5% proteome coverage, are identified from the cytosolic fraction of S. oneidensis, while requiring <500 ng of proteolytic digest loaded in the CIEF capillary. The ultrasensitive capabilities of electrokinetic-based proteome approach are attributed to the concentration effect in CIEF, the electrokinetic stacking of CITP, the nanoscale peak volume in CZE, the "accurate mass tag" strategy for protein/peptide identification, and the high-sensitivity, high-resolution, and high-mass measurement accuracy of FTICR-MS.