Theoretical and Experimental Studies of XUV Multielectron (Auto-)Ionization Dynamics in Helium and Molecular Hydrogen

This work consists of two parts: theoretical studies of laser-intensity dependent ionization processes in the helium atom and experimental attosecond transient-absorption spectroscopy studies of the (auto-)ionization dynamics of the Qn resonances of molecular hydrogen. In an experiment, motivating the simulations of ionization processes in helium, abrupt ionization of doubly excited states above a certain critical NIR-laser intensity was observed. Numerically solving the quantum-mechanical one-dimensional time-dependent Schrödinger equation for two electrons, the time-dependent population of relevant atomic states during the laser-pulse interaction is directly accessed. With respect to the theoretical results, an ionization mechanism for the doubly excited states is suggested, where non-sequential double ionization, arising due to electron– electron interaction, plays an important role. The investigations of the (auto-)ionization processes of doubly excited states in the hydrogen molecule concentrated on measuring timeand energy-dependent XUV absorption signals to separate the autoionization effects from the overall continuum absorption of H2. First results of (auto-)ionization effects in the hydrogen molecule were obtained in a technically challenging absorption spectroscopy study

Commuting Nonselfadjoint Operators and their Characteristic Operator-Functions

* Partially supported by Grant MM-428/94 of MESC.In this paper we present some generalizations of results of M. S. Livšic [4,6], concerning regular colligations (A1, A2, H, Φ, E, σ1, σ2, γ, ˜γ) (σ1 > 0) of a pair of commuting nonselfadjoint operators A1, A2 with finite dimensional imaginary parts, their complete characteristic functions and a class Ω(σ1, σ2) of operator-functions W(x1, x2, z): E → E in the case of an inner function W(1, 0, z) of the class Ω(σ1). ..

THE VALUE OF ECOLOGICAL AND ECONOMIC INFORMATION IN WATER QUALITY MANAGEMENT

Replaced with revised version of paper 08/25/03.Environmental Economics and Policy,

PANDEMIC CRISIS AND CURRENCY BOARD IN BULGARIA

The pandemic crisis, started as a health crisis and transformed to the economic crisis, had its negative effects not only on the real economy, but also on the financial sector all over the world. The origin of the crisis is different compared to the global financial crisis, but it affected on the behavior of the financial market participants and financial system functioning.Проблеми та перспективи розвитку фінансової системи в сучасних умовах : збірник матеріалів ІІІ Міжнародної науково-практичної інтернет-конференції (м. Полтава, 15–16 квітня 2021 року). – Полтава : ПУЕТ, 2021. – 301 с. – 1 електрон. опт. диск (DVD-ROM). – Текст укр., рос., англ. мовам

Influence of exogenous urea on photosynthetic pigments, 14CO2 uptake, and urease activity in Elodea densa-environmental implications

This paper analyzes the effect of exogenous urea in increased concentration gradient (0, 100, 500 and 1,000 mg L-1) on photosynthetic pigments (measured spectrophotometrically), uptake of 14CO2 (using radioisotope), and urease activity (by measuring ammonia with Nessler's reagent) in leaves of Elodea densa Planch. We have observed that low concentration of urea (100 mg L-1) stimulates the accumulation of photosynthetic pigments and intensifies photosynthesis in E. densa, whereas high concentration (1,000 mg L-1) suppresses these processes. Urease activity increased by approximately 2.7 and 8 fold when exogenous urea concentrations were 100 and 500 mg L-1, respectively. However, exogenous urea in high concentration (1,000 mg L-1) decreased urease activity by 1.5 fold compared to the control. The necessity of mitigating urea and other nitrogen-containing compounds (NH3 from urea) in water bodies has been discussed with emphasis on the potential for phytoremediation of urea using common water weed viz. E. densa. © 2013 Springer-Verlag Berlin Heidelberg

Government ownership and the cost of debt : evidence from government investments in publicly traded firms

Contrary to public perceptions and despite the worldwide success of state privatizations, over the past decade governments have acquired more assets through stock purchases (US$969 billion) than they have sold through share issue privatizations and direct sales (US$ 765 billion). In fact, governments and stateowned entities have been such active stock-market investors that they now own approximately one-fifth of global stock-market capitalization

Leaf Mesophyll Structure and Photosynthetic Activity in Calla palustris L. from Natural Habitats with Different Level of Technogenic Pollution

A study of leaf structure and CO2 assimilation rate was conducted on the emergent plant Calla palustris L. from natural habitats with different levels of technogenic pollution (the Sak-Elga River, upstream and downstream of the Karabash copper smelter, Chelyabinsk region, Russia). It was found that both chlorophyll a content andthe rate of CO2 assimilation decreased twofold in plants from the downstream site. No significant changes were observed in leaf mesophyll structure and the volume of aerenchyma in the leaf. It was shown that in plants from strongly contaminated site, the decrease in spongy mesophyll cell volume was compensated by the increase in their number, whereas the decrease in the number of chloroplasts per cell was accompanied by a growth in volume. It is concluded that the changes in the numerical and dimensional characteristics of mesophyll cells and chloroplasts provide for the viability of C. palustris under prolonged technogenic impact and demonstrate the plasticity of the photosynthetic apparatus. Keywords: emergent plant, heavy metals, adaptation, leaf structure, CO2 uptak

STUDY OF COLCHICINE EFFECTS ON ELECTROCONVULSIVE EPILEPTIC EQUIVALENT IN RATS

No abstrac

Effect of nitrogenous bases on the thermal stability of jet fuels

Fuels from naphthenic petroleums were evaluated, and it was found that they had more N bases than those paraffinic ones (0.00024 and 0.000009% N, respectively). The removal of the N bases improved significantly the thermal stability and reduced the residue formation during oxidation of the fuel. The improvement depended on both content and composition of the bases. Thus, fuels with similar content of N bases (0.00058% N) and thermal stability had oxidation residues of 17.5 and 5.6 and sol. gum of 13 and 1.5 mg/100 ml, before and after removing the N bases, respectively