Optimal allocation–consumption problem for a portfolio with an illiquid asset

During financial crises investors manage portfolios with low liquidity, where the paper-value of an asset differs from the price proposed by the buyer. We consider an optimization problem for a portfolio with an illiquid, a risky and a risk-free asset. We work in the Merton's optimal consumption framework with continuous time. The liquid part of the investment is described by a standard Black–Scholes market. The illiquid asset is sold at a random moment with prescribed distribution and generates additional liquid wealth dependent on its paper-value. The investor has a hyperbolic absolute risk aversion also denoted as HARA-type utility function, in particular, the logarithmic utility function as a limit case. We study two different distributions of the liquidation time of the illiquid asset – a classical exponential distribution and a more practically relevant Weibull distribution. Under certain conditions we show the smoothness of the viscosity solution and obtain closed formulae relevant for numerics.     

Inversion of the electron energy distribution in hollow-cathode glow discharge in nitrogen-sulfur hexafluoride gas mixture

The electron energy distribution function (EDF) in a hollow-cathode glow discharge in nitrogen-sulfur hexafluoride (N₂-SF₆) gas mixture has been studied by experimental and theoretical methods. On adding a small amount of SF₆ to N₂, the density of electrons in the energy interval (2−4 eV) of the EDF inversion increases by approximately one order of magnitude.     

The kinetic evidence for the formation of multiple active species in a bis(phenoxy-imine) zirconium dichloride/MAO catalyst during ethylene polymerization

The effects of polymerization time and temperature on the molecular weight and molecular weight distribution of polyethylene, produced over homogeneous catalyst bis[N-(3-tert-butyl salicylidene)anilinato]zirconium(IV) dichloride ^tBu-L₂ZrCl₂/MAO have been studied. The data on the number of active centers (C_P) and propagation rate constants (k_P) at different polymerization time have been obtained as well. It was found that at a short polymerization time two types of active centers, producing low molecular weight PE (M_w = (4-10) × 10³ g mol⁻¹) are formed. The number of these centers was estimated to be 11% of total zirconium complex and their reactivity is very high (the k_P value was found to be 54 × 10³ L mol⁻¹ s⁻¹ at 35 °C). High initial activity of the catalyst fell with the increase in polymerization time, whereas the polydispersity values of the resulting PE increase due to formation of new centers, producing high molecular weight PE (M_w = (30-1300) × 10³ g mol⁻¹). It was found that the decrease in activity is caused by reducing the initial active centers number and lower reactivity of the new-formed centers (k_P = 17 × 10³ L mol⁻¹ s⁻¹).     

Interaction between a ferromagnet and a high-temperature superconductor at the interface in thin-film heterostructures

The development of high-temperature superconductor (HTSC)/ferromagnet thin-film heterostructures is a promising direction in their application to spin-wave electronics. The state of the HTSC-ferromagnet interface determines the nature of the propagation of the surface magnetostatic waves in the heterostructure. The formation of the HTSC films in the heterostructures involves thermal treatment at high temperatures, which results in the diffusion interaction of the HTSC films and the ferromagnet. The heterostructure consists of a YBa₂Cu₃O_7−x HTSC film deposited by pyrolysis on an Y₃Fe₅O₁₂ ferromagnetic film grown epitaxially on a (111)-oriented gadolinum-gallium garnet Gd₃Ga₅O₁₂ substrate. The interdiffusion is studied from the intensity distribution curves of the x rays of iron (Fe), barium (Ba), copper (Cu), and silver (Ag), the last introduced into the HTSC in the amounts of 5–50 wt.%. The thin-film heterostructures are studied in the microwave range. A correlation is found between the state of the interface and the microwave characteristics. Pis’ma Zh. Tekh. Fiz. 23, 69–73 (June 26, 1997)     

The Ability of the Nitric Oxide Synthases Inhibitor T1023 to Selectively Protect the Non-Malignant Tissues

Previously, we showed that a nitric oxide synthase (NOS) inhibitor, compound T1023, induces transient hypoxia and prevents acute radiation syndrome (ARS) in mice. Significant efficacy (according to various tests, dose modifying factor (DMF)—1.6–1.9 against H-ARS/G-ARS) and safety in radioprotective doses (1/5–1/4 LD10) became the reason for testing its ability to prevent complications of tumor radiation therapy (RT). Research methods included studying T1023 effects on skin acute radiation reactions (RSR) in rats and mice without tumors and in tumor-bearing animals. The effects were evaluated using clinical, morphological and histological techniques as well as RTOG classification. T1023 administration prior to irradiation significantly limited the severity of acute RSR. This was due to a decrease in radiation alteration of the skin and underlying tissues, and the preservation of the functional activity of cell populations that are critical in the pathogenesis of radiation burn. The DMF values for T1023 for skin protection were 1.4–1.7. Moreover, its radioprotective effect was fully selective to normal tissues in RT models of solid tumors—T1023 reduced the severity of acute RSR and did not modify the antitumor effects of γ-radiation. The results indicate that T1023 can selectively protect the non-malignant tissues against γ-radiation due to hypoxic mechanism of action and potentiate opportunities of NOS inhibitors in RT complications prevention.     

Applicability of neutron activation analysis (NAA) in quantitative determination of some essential and toxic trace elements in food articles

Accurate and reliable data on microgram and nanogram quantities of some essential and toxic elements in most food articles are very scarce. Neutron activation analysis (NAA), with its essentially blankfree advantage, is a valuable approach in the field of determination of trace elements in different foodstuffs and diets. Accordingly, various radiochemical (RNAA) and instrumental (INAA) approaches have been developed in our laboratory for the elements As, Cd, Co, Cu, Hg, I, Mo, Ni, Sb, Se, Sn, Th, U, V, and others, and verified by the analysis of compositionally appropriate certified reference materials.This communication was presented as a poster at EURO FOOD CHEM VIII, Vienna, September 18–20, 1995, and was one of three such posters which were awarded as being outstanding     

Vapor-phase growth of Bi2Sr2Ca n−1Cu n O x (n= 1–3) single crystals

High-quality platelike Bi₂Sr₂Ca _n?1Cu_nO_x (n= 1–3) single crystals with superconducting transition temperatures T _c=10, 85, and 110 K, respectively, are prepared by vapor-phase growth in closed cavities produced in a melt fluxed with KCl. The effect of synthesis and growth conditions on the T _c of the crystals is analyzed. The morphology of the crystals suggests that the most perfect, well-faceted crystals grow via vapor transport with constant feeding from the charge.     

Study on polybenzoxazinone membrane in pervaporation processes

Poly(benz‐3,1‐oxazinone‐4) was prepared by thermal cyclization of its hydrolytically stable precursor polyamic acid. Both polymer and its precursor were investigated as membrane materials. Thermogravimetric analysis and contact angle measurements were carried out for characterization of peculiarity of membrane compositions and analysis of membrane surface. Pervaporation of water–isopropanol mixture was studied in the wide range of feed composition. To interpret the pervaporation transport properties of the membranes, swelling experiments were performed, kinetic curves of sorption and desorption were plotted, and basic sorption and diffusion parameters were analyzed. It was established that poly(benz‐3,1‐oxazinone‐4) membrane is extremely effective in dehydration of water–isopropanol mixture and shows high separation factor. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4024–4031, 2013     

Structural and superconducting properties of single-crystal Bi2Sr2Can ? 1CunO2n + 4 + δ (n = 1–3) whiskers grown in gas-filled cavities

Using growth inside gas-filled cavities in KCl-fluxed melts, we have obtained free-standing phasepure Bi₂Sr₂Ca _{n − 1}Cu _n O_{2n + 4 + δ} (n = 1–3) whiskers possessing superconducting properties in the as-grown state. Bi-2212 whiskers have been prepared in a wide range of doping levels, from underdoped (T _c = 76.5 K) to optimally doped (T _c = 84 K). The whiskers possess high structural perfection, as shown by X-ray diffraction. Annealing under optimal conditions raises the superconducting transition temperature of the underdoped Bi-2212 whiskers to T _{c max} = 85.5 K (ΔT _c = 1.8 K), without impairing their structural perfection. Original Russian Text ? M.V. Golubkov, Yu.I. Gorina, G.A. Kalyuzhnaya, V.V. Rodin, N.N. Sentyurina, V.A. Stepanov, S.G. Chernook, 2009, published in Neorganicheskie Materialy, 2009, Vol. 45, No. 6, pp. 731–737.