The rate of convergence in Orey's theorem for Harris recurrent Markov chains with applications to renewal theory

We derive sufficient conditions for ∝ λ (dx)6Pⁿ(x, ·) - π6 to be of order o(ψ(n)^-1), where Pⁿ (x, A) are the transition probabilities of an aperiodic Harris recurrent Markov chain, π is the invariant probability measure, λ an initial distribution and ψ belongs to a suitable class of non-decreasing sequences. The basic condition involved is the ergodicity of order ψ, which in a countable state space is equivalent to $\text{Σ ψ(n)}\text{P}{}_{\mathrm{i}}\text{{τ}{}_{\mathrm{i}}\text{?n} <∞}$ for some i, where τ_i is the hitting time of the tate i. We also show that for a general Markov chain to be ergodic of order ψ it suffices that a corresponding condition is satisfied by a small set.We apply these results to non-singular renewal measures on $\text{R}$ providing a probabilisite method to estimate the right tail of the renewal measure when the increment distribution F satisfies ∝ tF(dt) 0; > 0 and ∝ ψ(t)(1- F(t))dt< ∞.     

Determination of 14C, 55Fe, 63Ni and gamma emitters in activated RPV steel samples: a comparison between calculations and experimental analysis

Journal of Radioanalytical and Nuclear Chemistry - Determination of 14C, 55Fe, 63Ni and gamma emitters in two different types of activated reactor pressure vessel (RPV) steel samples were carried...     

Local dimensions of sliced measures and stability of packing dimensions of sections of sets

Let m and n be integers with 0<m<n. We relate the absolutely continuous and singular parts of a measure μ on to certain properties of plane sections of μ. This leads us to prove, among other things, that the lower local dimension of (n−m)-plane sections of μ is typically constant provided that the Hausdorff dimension of μ is greater than m. The analogous result holds for the upper local dimension if μ has finite t-energy for some t>m. We also give a sufficient condition for stability of packing dimensions of section of sets.     

A Tandem Mass Spectrometric Method for Singlet Oxygen Measurement

Singlet oxygen, a harmful reactive oxygen species, can be quantified with the substance 2,2,6,6‐tetramethylpiperidine (TEMP) that reacts with singlet oxygen, forming a stable nitroxyl radical (TEMPO). TEMPO has earlier been quantified with electron paramagnetic resonance (EPR) spectroscopy. In this study, we designed an ultra–high‐performance liquid chromatographic—tandem mass spectrometric (UHPLC‐ESI‐MS/MS) quantification method for TEMPO and showed that the method based on multiple reaction monitoring (MRM) can be used for the measurements of singlet oxygen from both nonbiological and biological samples. Results obtained with both UHPLC‐ESI‐MS/MS and EPR methods suggest that plant thylakoid membranes produce 3.7 × 10^?7 molecules of singlet oxygen per chlorophyll molecule in a second when illuminated with the photosynthetic photon flux density of 2000 μmol m^?2 s^?1.     

The Effect of Pure Component Characteristic Parameters on Sanchez–Lacombe Equation‐of‐State Predictive Capabilities

The dependence of predictive capabilities of SL EOS on the pure characteristic parameters of monomers and polymers is investigated. A sensitivity analysis study is carried out to understand the effect of these parameters on the predictive capability of SL EOS for different α‐olefin/polyolefins systems. Among all pure component characteristic parameters, the monomer characteristic temperature (T*_monomer) has the largest impact on SL EOS predictive capability; whereas the polymer characteristic density (ρ*_polymer) is found to have the smallest impact.

     

The Relationship Between the Microstructure and Physical Properties of Injection Molded Naphthalenic-Based Liquid Crystal Copolyester

Holding pressure was expected to change the free flow of the liquid crystalline melt. Because of the complex mold used and the two variables, nozzle and mold temperature, the shear and elongational flow were in the injection molding study evaluated by means of the notched Charpy and Izod impact strength. The tensile modulus, the flexural strength and modulus mainly depended on the elongational flow induced skin. On the grounds of the microstructure composed of 4 distinct layers a free flow model of the liquid crystal polymer having a yield stress is proposed.     

Deactivation in liquid-phase hydrogenation

Importance of investigating catalyst deactivation in the synthesis of fine chemicals is illustrated by several examples in three-phase hydrogenation reactions, performed in batch and continuous reactors. This revised version was published online in June 2006 with corrections to the Cover Date.     

Structural analysis of polyethene prepared with rac‐dimethylsilylbis(indenyl)zirconium dichloride/methylaluminoxane in a high‐temperature,continuously stirred tank reactor

A study of ethene solution polymerization with the rac‐dimethylsilylbis(indenyl)‐zirconium dichloride/methylaluminoxane catalyst system in a high‐temperature (140 °C), continuously stirred tank reactor system was carried out. ¹³C NMR, gel permeation chromatography, Fourier transform infrared, and rheological measurements were used for polymer analyses. Polyethylenes with low molecular weights (weight‐average molecular weight ≈ 35–55 kg/mol) and small amounts of methyl, ethyl, and long‐chain branching were produced. ¹³C NMR measurements showed that the long‐chain and methyl branches increased and that the ethyl branch contents decreased with decreasing monomer concentrations. At high monomer concentrations, the chain transfer to the coordinated monomer was concluded to be the predominant chain termination mechanism, whereas the chain transfer to aluminum was dominant at low monomer concentrations, which was evidenced by the fact that the selectivity of end groups was reduced to about 50%. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3292–3301, 2002     

Interpretation of KL2,3L2,3 radiative auger thresholds in metals and semiconductors

High-resolution measurements of the KL_2,3L_2,3 radiative Auger edge in Mg and Al are reported. The theory of soft X-ray absorption thresholds by Flynn and Lipari is modified to account for the KL_2,3L_2,3 threshold energies. The calculated energies are in excellent agreement with the experimental results including previous measurements on Si.