Solid state interactions in the systems CaO(CaCO3)-Fe2O3 and CuFe2O4-CaO

The solid state interactions in the systems CaO(CaCO3)-Fe2O3 and CuFe2O4-CaO have been studied using X-ray diffraction analysis. The influence of the temperature on the ferrite formation process has been investigated in the range of 900-1200 oC and duration up to 360 min. It has been shown that a mixture of ferrites forms at 1000 oC and interaction of 240 min. The exchange reactions in the systems CuFe2O4-CaO and Cu0.5Zn0.5Fe2O4-CaO have been studied, too. It has been established that Ca2+ ions exchange Cu2+ and Zn2 partially and the solubility of copper and zinc in a 7 % sulfuric acid solution increases 10-15 times

European Chemical Industry – Current State and Challenges

The European chemical industry is one of the major and most important industrial sectors of the Community economy. The present paper aims to present an analysis of its current state and, on this basis, to highlight the main challenges it must address in the coming years. The presentation of the main characteristics of the chemical industry on a global scale, which gives a clearer idea of the state of the industry as a whole also plays an important role in the study. The following main conclusions are drawn from the analysis made. First, an increase in the share of chemical substances and products in the EU’s total exports and imports, which determines the growing importance of the sector to the European Union. Second, the European chemical industry is still lagging behind China on a global scale due to a variety of reasons, including the country’s industrial policy and sector reforms. Third, in the future, the industry will have to cope with a number of challenges in areas such as the environment, international competitiveness, sustainable development and the circular economy

Three Essays in International Macroeconomics

This dissertation spans topics related to global trade, oil prices, optimum currency areas, the eurozone, monetary independence, capital controls and the international monetary policy trilemma. It consists of four chapters and three essays. Chapter one provides a brief summary of all three essays. Chapter two investigates the impact of oil prices on global trade. It is concluded that when oil prices increase, countries start trading relatively more with their neighbors. As an application this chapter provides a new estimate of the eurozone effect on trade. Chapter three continues to study the eurozone and asks whether it is an optimum currency area using the member countries’ desired monetary policies. It is concluded that Greece, Spain, and Ireland have desired policies that are the least compatible with the common euro policy and are therefore the least likely to have formed an optimum currency area with the euro. Chapter four provides a new methodology in testing the international trilemma hypothesis. It is concluded that the trilemma holds in the context of the Asian countries

Clinical utility of risedronate in postmenopausal osteoporosis: patient considerations with delayed-release formulation

Bisphosphonates are the most widely prescribed treatment for postmenopausal osteoporosis, secondary osteoporosis, and male osteoporosis. Notwithstanding their high effectiveness and favorable safety profile, the adherence to bisphosphonate treatment remains low. Different treatment strategies aim to improve the clinical effectiveness of bisphosphonate therapy. This review paper assesses the clinical utility of oral intermittent risedronate in the treatment of postmenopausal osteoporosis. The new delayed-release risedronate formulation is a safer and easy to use alternative to other risedronate therapy. Oral risedronate, a potent nitrogen-containing bisphosphonate, has been extensively studied using daily regimens. A new intermittent (weekly) dosing regimen confirmed its clinical effectiveness in relation to vertebral and nonvertebral fracture prevention. The absence of significant differences in the incidence of adverse effects confirmed the favorable tolerability of the weekly dosage. In efforts to improve patient adherence to treatment, an innovative, delayed-release formulation of risedronate, which ensures adequate bioavailability of the active compound when taken with food, was introduced. The once-weekly delayed-release formulation of risedronate proved to be noninferior to the daily dosage of risedronate in terms of bone mineral density and markers of bone turnover. In addition, the incidence of new morphometric vertebral fractures was comparable in both treatment regimens. The new delayed-release formulation of risedronate showed a favorable safety profile. Delayed-release risedronate is a promising, new, effective, and convenient alternative to current bisphosphonate treatments. It appears to allow better patient adherence to antiresorptive treatment

Automatic Detection of Laryngeal Pathology on Sustained Vowels Using Short-Term Cepstral Parameters: Analysis of Performance and Theoretical Justification

The majority of speech signal analysis procedures for automatic detection of laryngeal pathologies mainly rely on parameters extracted from time domain processing. Moreover, calculation of these parameters often requires prior pitch period estimation; therefore, their validity heavily depends on the robustness of pitch detection. Within this paper, an alternative approach based on cepstral- domain processing is presented which has the advantage of not requiring pitch estimation, thus providing a gain in both simplicity and robustness. While the proposed scheme is similar to solutions based on Mel-frequency cepstral parameters, already present in literature, it has an easier physical interpretation while achieving similar performance standards

Тинузавър – едновременно преподаване на програмиране, математика и физика

The need of business for specialists with a combination of competencies in different fields, especially in the context of the fourth industrial revolution, is the reason for the need to change the methods of teaching science. This also determines the growing popularity of STEM. One of the methods for achieving better results is the teaching of several disciplines, such as programming, mathematics and physics, simultaneously combined with work on highly practical projects

A software system for pathological voice acoustic analysis

International audienceA software system for pathological voice analysis using only the resources of a personal computer with a sound card is proposed. The system is written on the basis of specific methods and algorithms for pathological voice analysis and allows evaluation of: 1) Pitch period (To); 2) Degree of unvoiceness; 3) Pitch perturbation and amplitude perturbation quotients; 4) Dissimilarity of surfaces of the pitch pulses; 5) Ratio aperiodic/periodic components in cepstra; 6) Ratio {energy in the cepstral pitch pulse}-to-{total cepstral energy}; 7) Harmonics-to-noise ratio; 8) Degree of hoarseness; 9) Ratio low-to-high frequency energies; 10) Glottal Closing Quotient. The voices of 400 persons were analyzed - 100 (50 females/50 males) normal speakers and 300 (100 females/200 males) patients. The statistical analysis shows very significant changes in PPQ, DH, DPP, DUV, APR, HNR and PECM, and significant changes in APQ and CQ

Black hole inner horizon evaporation in semiclassical gravity

In this work we analyse the backreaction of a quantum field on a spherically symmetric black hole geometry with an inner horizon, i.e. an internal boundary of the trapped region. We start with a black hole background with an inner horizon which remains static after its formation. We quantise a massless scalar field on it and calculate its renormalised stress-energy tensor in the Polyakov approximation. We use this tensor as a source of perturbation on top of the background spacetime. We find that the inner horizon has a tendency to evaporate outward much more quickly than the outer one evaporates inward through the Hawking effect. This suggests a revised picture of a semiclassically self-consistent evaporation in which the dominant dynamical effect comes from the inner horizon. We also look at backreaction on backgrounds which resemble gravitational collapse, where the inner horizon moves toward the origin. There we find that, depending on the nature of the background dynamics, horizon-related semiclassical effects can become dominant and invert the collapse.Comment: 31 pages, 10 figure

Asymptotic horizon formation, spacetime stretching and causality

In this work we analyse asymptotically flat, spherically symmetric spacetimes in which an event horizon is present without any trapped surfaces. We identify two types of such spacetimes, each related to the asymptotic behaviour (in time) of one of the two degrees of freedom of the metric. We study the causal structure of both types, showing that one almost always has a Cauchy horizon beyond which it is extendable, while the other is inextendable but has two separate future null infinity regions on either side of the horizon. We also study what energy conditions can be satisfied by the matter around the horizon. Some of these spacetimes were first introduced in an earlier work in which semiclassical effects near black-hole horizons were analysed. Here we generalise this analysis to a larger family of geometries.Comment: 12 pages, 5 figures; v2: minor changes to match published versio