Geometric phase decomposition in the basis of Hermite-Gaussian functions

The work presents geometric phase decomposition for analytical signals using Hermite-Gaussian functions. The decomposition is based on the time-frequency distribution with reassigned and multi-tapered spectrogram resulting in increased phase estimation resolution. Numerical analysis is applied to a number of SU(2) evolutions, such as spin-1/2 particle in a static and rotating magnetic field, as well as polarization rotation of a plane wave in optically active medium. Geometric phase decomposition results are provided also for quantum harmonic oscillator and a radiation field of an electric dipole exited by a short pulse.     

Development and Evaluation of Decision-Making Model for Stock Markets

The paper introduces an intelligent decision-making model which is based on the application of artificial neural networks (ANN) and swarm intelligence technologies. The proposed model is used to generate one-step forward investment decisions for stock markets. The ANN are used to make the analysis of daily stock returns and to calculate one day forward decision for purchase of the stocks. Subsequently the Particle Swarm Optimization (PSO) algorithm is applied in order to select the “the best” ANN for the future investment decisions and to adapt the weights of other networks towards the weights of the best network. The experimental investigations were made considering different forms of decision-making model: different number of ANN, ANN inputs, sliding windows, and commission fees. The paper introduces the decision-making model, its evaluation results and discusses its application possibilities.     

Effect of pozzolanic waste materials on hydration peculiarities of Portland cement and granulated expanded glass-based plaster

Journal of Thermal Analysis and Calorimetry - The article analyses the peculiarities of the combined effect on hydration process of the following pozzolanic additives: metakaolin waste (MW),...     

Effect of milled fluidised bed cracking catalyst waste on hydration of calcium aluminate cement and formation of binder structure

The effect of Bi addition on precipitation and dissolution, in Cu–9at% In and Cu–5at% Sb supersaturated solid solutions, has been studied by several complementary techniques. Differential Dilatometry and Differential Scanning Calorimetry permit only the analysis of the δ phase dissolution kinetic in sufficiently aged samples. Delayed spheroidization due to Bi segregation around the precipitated lamellae, observed by Transmission Electron Microscopies in the first alloy, gives a residual interfacial energy leading to accelerated δ phase dissolution with decreased activation energy. Kinetics parameters evolution indicates a progressive δ phase continuous dissolution which makes available a small chemical driving force at high temperatures and leads to an increasing activation energy during dissolution. However, Bi dispersed particles in the second alloy haven’t effect on the dissolution but they cause a contraction above 833 K. Kinetics parameters evolution indicates rapid δ phase dissolution that shifted to high temperatures where an important chemical driving force for solution treatment is available. It leads to almost constant activation energy.

     

Toric Surface Patches

We define a toric surface patch associated with a convex polygon, which has vertices with integer coordinates. This rational surface patch naturally generalizes classical Bézier surfaces. Several features of toric patches are considered: affine invariance, convex hull property, boundary curves, implicit degree and singular points. The method of subdivision into tensor product surfaces is introduced. Fundamentals of a multidimensional variant of this theory are also developed.     

Investigating the hydration of deflocculated calcium aluminate cement-based binder with catalyst waste

The hydration of the binder, consisting of calcium aluminate cement (CAC) with Al₂O₃ >70% and with or without the additives of the FCC catalyst waste and polycarboxylate deflocculant Castament FS-20, is investigated. The methods of calorimetry, thermal analysis, XRD, electrical conductivity, SEM, as well as ultrasonic wave velocity measuring and bending strength evaluation are used. The results of the investigation show that the FCC catalyst as well as polycarboxylate deflocculant, are active additives, influencing the CAC binder??s hydration process. In the structure of the hardened binders, certain amounts of unhydrated CAC minerals, CA, and CA₂, and the hydration products, such as CAH₁₀, C₂AH₈ and the amorphous AH₃, are found. However, in the binder with a deflocculant, there are smaller amounts of CAH₁₀ and the amorphous AH₃, though the amount of C₂AH₈ is higher than that in the binder without a deflocculant additive. It has been found that in the case, when the FCC catalyst and deflocculant are simultaneously used, the FCC catalyst produces a positive effect on the formation of the CAC binder??s structure, increasing its mechanical strength. The results obtained in this article allow to predict that the FCC catalyst and deflocculant simultaneously used as the additives to the CAC binder, will enable to control the hydration process of the binder.     

<Emphasis Type="Italic">In situ</Emphasis> study of the <Superscript>41</Superscript>Ar plume released from the Ignalina NPP

The ⁴¹Ar gamma ray radiation was registered using the in situ method in the vicinity of the Ignalina nuclear power plant (NPP). The sum of gamma rays, that are reaching the HPGe detector, situated along the wind direction, from a number of plume segments and which are registered in the energy range of about 1.29 MeV, is calculated. An independent technological regime of the operating reactor method of the determination of the ⁴¹Ar emission rate from NPP stack is introduced.      

Investigation of ageing of alumina cement-based mixtures using thermal analysis and calorimetry

The shelf life of cement and cement-based dry mixtures is often determined by ageing of such materials. The ageing is the result of interactions between cement and other components of cementitious mixtures with moisture as well as with CO₂ from the atmosphere. In this work, the ageing behaviour of calcium aluminate cement and its mixtures with additives of microsilica, fluidized catalytic cracking catalyst waste and ground quartz sand were investigated. The ageing was achieved by storing cement and its mixtures in a climatic chamber for 7 and 14 days at 95% relative humidity and 20 ± 1 °C temperature. Applying thermal analysis, XRD analysis as well as scanning electronic microscopy, it was established that hydration of the cement minerals takes place along with carbonation during the ageing process of cement and its mixtures. The quantities of the products formed during ageing and their crystallinity depend on the nature of additives and the duration of ageing. When applying the method of calorimetric analysis, the influence of ageing on the kinetics of hydration of cement and as well as of its mixtures with the additives used in the work has been established.