Regeneration and renovation in queues

Regenerative events for different queueing models are considered. The aim of this paper is to construct these events for continuous-time processes if they are given for the corresponding discrete-time model. The construction uses so-called renovative events revealing the property of the state at timen of the discrete-time model to be independent (in an algebraic sense) of the states referring to epochs not later thann −L (whereL is some constant) given that there are some restrictions on the “governing sequence”. Different types of multi-server and multi-phase queues are considered.     

Resonance-enhanced multiphoton ionisation photoelectron spectroscopy of the ClO radical: the C 2 sigma- state

A (2 + 1) one-colour resonance-enhanced multiphoton ionisation study is carried out on the C 2 sigma- state of the ClO radical in the one-photon energy range 29,500-31,250 cm-1. The ClO radical is produced by one-photon photolysis of ClO2 employing 359.2 nm photons derived from a separate laser. In this way a significant concentration of vibrationally excited ClO in its spin-orbit split X 2 pi omega (omega = 3/2 or 1/2) electronic ground state is produced. In addition to mass-resolved excitation spectra, kinetic-energy resolved photoelectron spectra for the X 3 sigma-(v+)<--C 2 sigma-(v' = 3-5) transitions are measured. These transitions are not completely Frank-Condon diagonal, and indicate a decrease in bond length on removal of the Rydberg electron from the C 2 sigma- state. In addition to an unambiguous assignment of the C 2 sigma- state, valuable information is obtained on the degree of vibrational excitation with which the nascent ClO radical is formed in the photolysis of ClO2. Analysis of the photoelectron spectra is supported by Franck-Condon calculations based on potential energy curves either from experimental spectroscopic parameters, or obtained by theoretical ab initio methods.     

Thermal oxidative stability of poly-p-xylylenes

The air oxidation of poly-p-xylylene films was studied at temperatures between 125 and 200°C. The oxidation kinetics were obtained from neutron activation (NA) oxygen analyses and infrared (IR) Spectroscopy. A correlation between the NA oxygen analyses and mechanical properties indicated that the amount of oxygen incorporated into these polymers before a significant degradation mechanical properties is about 1000 ppm for poly(dichloro-p-xylylene) and 5000 ppm for poly(monochloro-p-xylylene) or poly-p-xylylene. The activation energy for the oxidation of these polymers was about 30 kcal/mole. Long-term-use (100,000 hr) temperatures were also estimated for each of the poly-p-xylylenes studied. The 100,000-hr maximum continuous-use temperature is 112°C for poly(dichloro-p-xylylene), 72°C for poly(monochloro-p-xylylene), and 57°C for poly-p-xylylene.     

Reversible Phosphaalkene Formation Frol'i Iminodi-Phosphines

Abstract

Addition of variousnucleophiles to phosphaalkenes is considered to be irreversible. As an example, the quantitative formation of iminodiphosphine III from phosphinous amide and phosphaalkene was recently reported (1).     

Multicriteria mapping of stakeholder preferences in regulating nanotechnology

In order to facilitate stakeholder discussions on how to regulate nanotechnology, the opensource program multicriteria mapping (MCM) was used to structure 26 interviews with stakeholders in the USA. MCM offers a systematic part quantitative, part qualitative approach to clarify why some regulatory options (bans, moratoriums, voluntary measures, etc.) were deemed to be acceptable/unacceptable by various stakeholders and which criteria stakeholders used to evaluate the different regulatory options. Adopting an incremental approach and implementing a new regulatory framework was evaluated as the best options whereas a complete ban and no additional regulation of nanotechnology were found to be the least favorable. Criteria applied differed substantially among stakeholders and included social, ethical, regulatory, environmental, and health issues. Opinions on future regulation seem far less polarized than expected and it seems that stakeholders would welcome a combination of voluntary measures, an incremental approach and forming of a new regulatory framework.     

Molecular and crystal structure of 2-(2-p-tolyloxyethoxy)ethylchloroacetate

2-(2-p-Tolyloxyethoxy)ethylchloroacetate is synthesized and its single crystal X-ray diffraction analysis is performed.     

PARALLEL AUXILIARY SPACE AMG FOR H（curl） PROBLEMS

In this paper we review a number of auxiliary space based preconditioners for the second order definite and semi-definite Maxwell problems discretized with the lowest order Nedelec finite elements. We discuss the parallel implementation of the most promising of these methods, the ones derived from the recent Hiptmair-Xu （HX） auxiliary space decomposition [Hiptmair and Xu, SIAM J. Numer. Anal., 45 （2007）, pp. 2483-2509]. An extensive set of numerical experiments demonstrate the scalability of our implementation on large-scale H（curl） problems.