Synthesis and Characterization of a New Sillenite Compound—Bi12(B0.5P0.5)O20

A new sillenite compound, Bi₁₂(B_0.5P_0.5)O₂₀, was synthesized using a solid-state reaction method. The stoichiometry was confirmed by XRD analyses, microstructural investigations, and quantitative elemental analysis. An investigation of the dielectric properties at frequencies from 100 Hz to 1 MHz revealed a broad, highly frequency-dispersive, relaxor-like dielectric anomaly, which appeared in the temperature range of −80°–100°C. The permittivity, Q × f value, and temperature coefficient of the resonant frequency, measured at ∼5.5 GHz, were determined to be 37.4, 850 GHz, and −19 ppm/K, respectively.     

WSDL and UDDI extensions for version support in web services

Versioning is an important aspect of web service development, which has not been adequately addressed so far. In this article, we propose extensions to WSDL and UDDI to support versioning of web service interfaces at development-time and run-time. We address service-level and operation-level versioning, service endpoint mapping, and version sequencing. We also propose annotation extensions for developing versioned web services in Java. We have tested the proposed solution for versioning in two real-world environments and identified considerable improvements in service development and maintenance efficiency, improved service reuse, and simplified governance.     

Simulation of cutting forces in ball-end milling

The paper presents a simulation system (SCP) that determines the cutting forces in the ball-end milling process. The system is based on numerical methods, computer programme, theoretical knowledge of technological processes, machining and tests performed. The system for simulation of the cutting process combines the technological data base, the analytical and experimental model and the data base SCP. The experimental model contains a collection of variables of the cutting process by means of sensors and transformation of those data into numerical values, which are a starting point for data calculation of characteristic coefficients of materials. The analytical model is used to estimate the tangential, radial and axial cutting forces, along with a material data base obtained from cutting experiments. Ball-end milling test has been conducted to verify simulation results. The simulation results, are the basis for the development of the tool-designing model and for the model of optimization of the machining process cutting parameters.     

BUSINESS EXCELLENCE IN PUBLIC-UTILITY COMPANIES BY INNOVATIVENESS BASED ON DIALECTICAL SYSTEMS THINKING

Bertalanffian systemic thinking attacks over-specialization and tries to teach humans how to attain holism for humankind to survive. Indirect ways may support this crucial intention better, including business excellence, which enjoys the support of, for example, the European Quality Award (EFQM/EQA). But in some industries, such as public utilities working on waste problems, market and EFQM/EQA do not support systemic thinking well enough. The new model presented herein has been evolving for over ten years and has proven successful in practice in the public utility companies.     

Asphalt concrete modification with waste PMMA/ATH

This paper presents recycling of waste PMMA/ATH powder in asphalt concrete mixture. Waste PMMA/ATH is generated in large amounts during shaping process of acrylic sheets. Recycling waste polymers rationally and efficiently has become one of the priorities of road pavement industry in recent years. Therefore, in this study waste PMMA/ATH powder was incorporated in an asphalt mixture. In one case waste PMMA/ATH was used as an asphalt binder modifier and in other case as a partial replacement for fine aggregate fraction. Basic performance characteristics of asphalt mixtures were evaluated by measuring material properties such as rutting potential and stripping resistance. Binder characteristics were determined also on artificially aged samples. With both modification methods, improved performance characteristics of asphalt mixture were achieved which can increase road pavement durability. Finally, waste PMMA/ATH allowed us to prepare an asphalt mixture that had strongly enhanced mechanical properties regarding to the wheel tracking test and could also have less negative effects on the environment as indicated by moisture susceptibility test results.     

The Turing Machine May Not Be the Universal Machine

Minds and Machines -     

Autonomous evolutionary algorithm in medical data analysis

An autonomous evolutionary algorithm for constructing decision trees is presented. The algorithm requires no or minimal human interaction and shows some interesting properties when used on different medical datasets. The algorithm uses a non-standard implicit fitness evaluation in the selection phase of a co-evolving environment. Together with self-adaptation of evolution parameters and with some other improvements it can monitor and adjust its own behavior. The algorithm's capability to self-adapt to a given problem is used as a measure to predict if some dataset is just difficult or impossible to analyze. The autonomous algorithm on average produces very general solutions or gives no solution if the dataset is prone to the overfitting problem.     

Dielectric Relaxations in Bi2O3–Nb2O5–NiO Cubic Pyrochlores

Dielectric properties of pyrochlores compositions from Bi₂O₃–Nb₂O₅–NiO system were analyzed. The dielectric properties are dominated with a low-temperature relaxation that is typical for Bi-pyrochlores. A vast pyrochlore homogeneity range that exists in this system allowed to correlate characteristics of the observed relaxations with a compositional variations within the A₂O'- and B₂O₆ pyrochlore sublattice. It was possible to make a distinction between different influences of the two sublattices, which can be satisfactorily described by the existing relaxation model for Bi_3/2ZnNb_3/2O₇. A new relaxor-like room temperature relaxation was found for Bi_1.6Ni_0.57Nb_1.43O_6.55.     

Single-step preparation of rutile-type CrNbO4 and CrTaO4 oxides from oxalate precursors–characterization and properties

Chromium niobate and tantalate (CrNbO₄ and CrTaO₄) were synthesized by pyrolysis of the oxalate-based heterometallic complexes [Cr₂(bpy)₄(μ-O)₄Nb₂(C₂O₄)₄]·3H₂O (Cr-Nb) and [Cr(bpy)₂(H₂O)(μ-O)Ta(C₂O₄)₃]₂·3.5H₂O (Cr-Ta) (bpy = 2,2'-bipyridine). Compared to conventional solid-state synthesis, herein studied oxides are prepared at lower temperatures, in one step without repeating grinding procedures. The structure, morphology, and optical properties of the as-synthesized oxides were characterized using powder X-ray diffraction (PXRD), field emission scanning electron microscopy (SEM), the thermogravimetric and differential thermal analysis (TG/DTA) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The determined band gap energies of CrNbO₄ and CrTaO₄ are 2.39 and 2.82 eV, respectively, which prompted us to investigate photocatalytic activity of these oxides in degradation of dyes. Microscopy studies show that the particles of both oxides began to aggregate into bigger particles, leading to an increase in grain size. Additionally, magnetization measurements on both oxides revealed spin-glass behavior at low temperatures.