Algebraic Approach to Molecular thermodynamics

An algebraic model based on Lie-algebraic and discrete symmetry techniques is applied to the analysis of thermodynamic vibrational properties of molecules. The local anharmonic effects are described by a Morse-like potential and the corresponding anharmonic bosons are associated with the SU(2) algebra. A vibrational high-temperature partition function and the related thermodynamic functions are derived and studied in terms of the parameters of the model. The idea of a critical temperature is introduced in relation with the specific heat. A physical interpretation of a quantum deformation associated with the model is given.Comment: 18 pages, 6 figures, submitted to J Physics: Condensed Matte

Squeezed coherent states and the one-dimensional Morse quantum system

The Morse potential one-dimensional quantum system is a realistic model for studying vibrations of atoms in a diatomic molecule. This system is very close to the harmonic oscillator one. We thus propose a construction of squeezed coherent states similar to the one of harmonic oscillator using ladder operators. Properties of these states are analysed with respect to the localization in position, minimal Heisenberg uncertainty relation, the statistical properties and illustrated with examples using the finite number of states in a well-known diatomic molecule.Comment: 15 pages, 10 figures. $\bullet$Revised section 4, results unchanged. Correction of formulas 35 and 37. Results unchanged because all variables are real numbers. arXiv admin note: substantial text overlap with arXiv:1010.327

Simple Applications of q-Bosons

A deformation of the harmonic oscillator algebra associated with the Morse potential and the SU(2) algebra is derived using the quantum analogue of the anharmonic oscillator. We use the quantum oscillator algebra or $q$-boson algebra which is a generalisation of the Heisenberg-Weyl algebra obtained by introducing a deformation parameter $q$. Further, we present a new algebraic realization of the $q$-bosons, for the case of $q$ being a root of unity, which corresponds to a periodic structure described by a finite-dimensional representation. We show that this structure represents the symmetry of a linear lattice with periodic boundary conditions.Comment: LATEX2e, 10 pages, v2: few misprints corrected, added Journal-re

Non-Woven Textiles in the Indoor Environment

The chapter presents the basic metrics of the indoor environment that are used to assess the quality of living and working, together with the risk factors and pollutants indoors. From this point of view the non-woven textiles are presented and discussed. Different groups of non-woven materials are considered: floor coverings, wallcoverings, upholstery and furniture textiles, filters of the HVAC systems, etc. Their particular application on the indoor environment is presented and their effect on the metrics of the Indoor Environmental Quality (IEQ) is analyzed

Working in Cold Environment: Clothing and Thermophysiological Comfort

The chapter presents an in-depth discussion over the occupational activities in a cold environment, which can be performed both outdoors and indoors. It explores the differences between working in natural and artificial cold environment. The thermophysiological comfort, the reactions of the thermoregulatory system during cold exposure, and cold-related injuries are presented and discussed in detail. Clothing as the only insulating barrier between the body and the cold environment is discussed, and hi-tech solutions for development of cold protective clothing are presented. The particular application of standards for the indoor environment is presented, and their input for the proper management of the occupational activities in the cold is analyzed

Adaptation of Traditional Carpet Motifs to Modern Textiles

Smooth surface carpets are the most typical for the hand woven carpets in Bulgaria. The nowadays production of traditional woven carpets faces several difficulties, however. Therefore the design of smaller, frequently used items, art works and souvenirs could be a key solution for preservation of the carpet. This study would like to draw the attention to Chiprovtsi carpets, as the tradition of carpet-weaving in this Bulgarian town was recently (2014) inscribed on the UNESCO Representative List of Intangible Cultural Heritage. The preservation of the carpets motifs is of importance for the cultural heritage; and their larger dissemination can give them new, meaningful life in the modern times. The study presents basic motifs in the weaving of Chiprovtsi carpet, which are typical, and can be used for designing of new woven items. The motifs adaptation in textile items of today is shown. The design of an ethno bag with woven motifs from old carpets is demonstrated. Keywords: carpet motifs, Bulgarian carpets, Chiprovtsi carpet

Bulgarian experience in the development of inclusive education in modern school

Access to quality education for children with disabilities is the modern reform of Bulgarian education in the conditions of globalization of the Bulgarian education and its unity with the European Union. It is necessary to achieve compliance with the Bulgarian educational organizations with European standards in this area. However, at this stage of development, there are many problems to be solvedСовременная реформа болгарского образования в условиях глобализации системы образования в условиях присоединения Болгарии к Евросоюзу предусматривает создание доступа к качественному образованию для детей с особенностями здоровья. Необходимо достичь соответствия болгарских образовательных организаций европейским стандартам в этой области. Вместе с тем на данном этапе развития существует много проблем, требующих решени

Global Stability and Periodicity in a Glucose-Insulin Regulation Model with a Single Delay

A two-dimensional system of differential equations with delay modelling the glucose-insulin interaction processes in the human body is considered. Sufficient conditions are derived for the unique positive equilibrium in the system to be globally asymptotically stable. They are given in terms of the global attractivity of the fixed point in a limiting interval map. The existence of slowly oscillating periodic solutions is shown in the case when the equilibrium is unstable. The mathematical results are supported by extensive numerical simulations. It is shown that typical behaviour in the system is the convergence to either a stable periodic solution or to the unique stable equilibrium. The coexistence of several periodic solutions together with the stable equilibrium is demonstrated as a possibility.Comment: Accepted to Communications in Nonlinear Science and Numerical Simulatio