Sharing delay information in service systems: a literature survey

Service providers routinely share information about upcoming waiting times with their customers, through delay announcements. The need to effectively manage the provision of these announcements has led to a substantial growth in the body of literature which is devoted to that topic. In this survey paper, we systematically review the relevant literature, summarize some of its key ideas and findings, describe the main challenges that the different approaches to the problem entail, and formulate research directions that would be interesting to consider in future work.     

Effect of surfactant on electrokinetic properties of polyindole/TiO2-conducting nanocomposites in aqueous and nonaqueous media

In this study, polyindole (PIN)/TiO₂ nanocomposites were synthesized with and without the presence of sodium dodecylsulfate, anionic surfactant, with two different PIN contents. The synthesized materials were subjected to various characterizations namely: particle size, apparent density, conductivity, dielectric constants, magnetic susceptibility, elemental analysis, Fourier transform infrared spectroscopy spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Characterization results revealed the successful preparations of PIN/TiO₂ hybrid nanocomposites. Electrokinetic properties of all the materials were determined by zeta (ζ)-potential measurements in aqueous and nonqueous media. Effects of pH, temperature, presence of various electrolytes, and surfactants on electrokinetic properties of the materials were examined.     

Synthesis and chemistry of the bis(trimethylsilyl)amido bis-tetrahydrofuranates of the group 2 metals magnesium, calcium, strontium and barium. X-ray crystal structures of Mg[N(SiMe3)2]2·2THF and related Mn[N(SiMe3)2]2·2THF

Transamination reactions utilizing the compound mercuric bis(trimethylsilyl)amide, Hg{N(SiMe₃)₂}₂, in tetrahydrofuran (THF), and the metals Na, Mg, Ca, Sr, Ba and Al have been investigated. Thus the THF solvated compounds Na[N(SiMe₃)₂]·THF and M[N(SiMe₃)₂]₂·2THF, M = Mg, Ca, Sr and Ba (1–4), have been prepared. The X-ray crystal structures of 1 and the related manganese compound Mn[N(SiMe₃)₂]₂·2THF (5) are reported. Interaction of the silylamides, 2–4, with a range of crown ethers apparently proceeded with elimination of silylamine, (Me₃Si)₂NH, and novel ring opening of the crown ethers, generating species containing a donor alkoxide ligand with a vinyl ether function, presumably, ---O(CH₂CH₂O)_nCH=CH₂ (n = 3−5). The silylamides 2–4 were also cleanly converted to the corresponding alkoxides (from ¹H NMR data) in reactions with stoichiometric quantities of 3-ethyl-3-pentanol.     

Hydrogen determination in coal samples by the recoil proton method

Radioiodine adsorption from aqueous solutions on metal-containing membranes with different compositions have been investigated. Radioiodine can be adsorbed from aqueous media using Bi- or Ag-containing membrane filters. The results of testing the metal-containing membrane filters with NPP water coolant samples are presented. A procedure for the determination of radioiodine in the NPP water coolant is developed.     

A comparison between rate-equation and Fabry-Perot amplifier models of injection locked laser diodes

The rate-equation and the Fabry-Perot amplifier models for injection locked laser diodes are compared. Both models give identical results at the limiting case of no injected signal. The Fabry-Perot model predicts a wider locking bandwidth and is more useful for large signal applications. The rate-equation model is suitable for investigating the dynamic properties. Numerical results from both models are presented.