A note on the subexponential asymptotics of the stationary distribution of M/G/1 type Markov chains

Masuyama (2011) obtained the subexponential asymptotics of the stationary distribution of an M/G/1 type Markov chain under the assumption related to the periodic structure of G-matrix. In this note, we improve Masuyama’s result by showing that the subexponential asymptotics holds without the assumption related to the periodic structure of G-matrix.     

Exponential Behavior of Solutions to Stochastic Integrodifferential Equations with Distributed Delays

In this work, we study the existence, uniqueness, and exponential asymptotic behavior of mild solutions to stochastic integrodifferential delay evolution equations. We assume that the non-delay part generates a C₀-semigroup.     

Phase behavior of (CO2 + methanol + lauric acid) system

In this study the phase equilibrium behaviors of the binary system (CO₂ + lauric acid) and the ternary system (CO₂ + methanol + lauric acid) were determined. The static synthetic method, using a variable-volume view cell, was employed to obtain the experimental data in the temperature range of (293 to 343) K and pressures up to 24 MPa. The mole fractions of carbon dioxide were varied according to the systems as follows: (0.7524 to 0.9955) for the binary system (CO₂ + lauric acid); (0.4616 to 0.9895) for the ternary system (CO₂ + methanol + lauric acid) with a methanol to lauric acid molar ratio of (2:1); and (0.3414 to 0.9182) for the system (CO₂ + methanol + lauric acid) with a methanol to lauric acid molar ratio of (6:1). For these systems (vapor + liquid), (liquid + liquid), (vapor + liquid + liquid), and (solid + fluid) transitions were observed. The phase equilibrium data obtained for the systems were modeled using the Peng–Robinson equation of state with the classical van der Waals mixing rule with a satisfactory correlation between experimental and calculated values.     

Application of spectroscopic techniques: ICP-OES, LA-ICP-MS and chemometric methods for studying the relationships between trace elements in clinical samples from patients with atherosclerosis obliterans

The study was aimed to evaluate the influence of the vascular disease, atherosclerotic obliterans (AO), on the location and concentration of elements in the arterial wall and serum. Use of a modern method for studying element’s concentration and distribution in samples of clinical material, i.e. laser ablation inductively coupled plasma mass spectrometry, is presented. Elements are not equally distributed between the inner (intima) and the outer (media + adventitia) layer of the arterial wall. Among the studied elements, calcium was found to have an unquestionable role in the calcification of the wall. Increased concentration of calcium found in the inner part of the atherosclerotic arterial wall and in the plaque, as compared to the control arterial wall samples, demonstrates the unquestionable role of this element in the calcification of the wall observed in AO. Applied chemometric methods were useful for demonstrating the differences in the element’s concentration in blood serum and the arterial wall samples between AO and the control group.     

Mössbauer effect and NMR studies of copper-cadmium ferrites

Hyperfine magnetic field distributions have been observed at room temperature in Cd _x Cu_1?x Fe₂O₄ (0≤x≤0.5) ferrites by the Mössbauer and NMR methods and are explained by statistical distributions of metallic ions separately within A and within B crystal sublattices.     

507—Electron transport through human epithelial amniotic membrane in vitro: Comparative study with artificial membranes (bilayer and millipore filters)

The transfer of solutes and water across the amniotic membrane, in vivo, is controlled by hydraulic, osmotic and electrochemical factors. In this study the electrochemical component is specified in vitro, and the mechanism of ion transport across the amnion is characterized by comparison with artificial membranes (bilayers and Teflon millipore filters). The electrochemical study shows that the amniotic conductance depends on time and salt concentration; the cationic transference number is comprised between 0.75 and 0.85; the electro-osmotic potentials are negative; the I(V) curves are linear; the activation conductance energy ranges between 4 and 8 kcal degree^?1 mole^?1 and the cation selectivity sequence is: RbCsK>Na>Li. The pharmacological agents (ouabain, amiloride, dinitrophenol) decrease gNa. These results suggest: (1) that the amnion has fixed neutral sites in external epithelial cell membranes and on intercellular channels with, under certain conditions, negative sites in greater number than positive sites; (2) that the amnion is comparable to negative artificial membranes; (3) that the paracellular pathway is more important than the transcellular pathway; (4) that there are specific sites on the external membranes and in intercellular channels.     

Regularly varying tail of the waiting time distribution in M/G/1 retrial queue

We consider an M/G/1 retrial queue where the service time distribution has a regularly varying tail with index −β, β>1. The waiting time distribution is shown to have a regularly varying tail with index 1−β, and the pre-factor is determined explicitly. The result is obtained by comparing the waiting time in the M/G/1 retrial queue with the waiting time in the ordinary M/G/1 queue with random order service policy.