Phosphorus(III)-Nitrogen-Sulphur Compounds: Synthesis and Metal Complexes

Abstract

The preparation and X-ray structure (M=Mo) of complexes of the type M(CO)₅(Ph₂PNSO) (M=Cr,Mo) are described. These complexes are used in the synthesis of homo- and hetero-dinuclear complexes of Ph₂PNSNPPh₂. A ³¹P DNMR study of these dinuclear complexes indicates a cis, trans → trans, cis isomerization in solution. The preparation and X-ray structure (M=Cr) of the mononuclear complexes, cis-M(CO)₄(P(Ph)₂NSN(Ph)₂P), (M=Cr,Mo) are also described.     

Porous microcapsule formation with microsieve emulsification

A simple route is presented to prepare core-shell Eudragit microcapsules through a solvent extraction method with the use of microsieve emulsification. Droplets from a solution of Eudragit FS 30D (a commercial copolymer of poly(methyl acrylate-co-methyl methacrylate-co-methacrylic acid) 7:3:1) and hexadecane in dichloromethane are dispersed into water, using a micro-engineered membrane with well-defined pores, in a cross-flow setting. The dichloromethane is extracted from the droplets, which induces demixing in the droplets, leading to a hexadecane-rich core, and an Eudragit-rich shell. The obtained microcapsules have a narrow size distribution due to the microsieve emulsification process. The capsules have a porous shell as shown by SEM and AFM measurements. Their porosity and pore size is dependent on the ratios of Eudragit and hexadecane in the dispersed phase. At pH 7.1 and above Eudragit (FS 30D) dissolves in water; this pH change is used to release the contents of the microcapsule.     

An evaluation of objective measures for intelligibility prediction of time-frequency weighted noisy speech

Existing objective speech-intelligibility measures are suitable for several types of degradation, however, it turns out that they are less appropriate in cases where noisy speech is processed by a time-frequency weighting. To this end, an extensive evaluation is presented of objective measure for intelligibility prediction of noisy speech processed with a technique called ideal time frequency (TF) segregation. In total 17 measures are evaluated, including four advanced speech-intelligibility measures (CSII, CSTI, NSEC, DAU), the advanced speech-quality measure (PESQ), and several frame-based measures (e.g., SSNR). Furthermore, several additional measures are proposed. The study comprised a total number of 168 different TF-weightings, including unprocessed noisy speech. Out of all measures, the proposed frame-based measure MCC gave the best results (ρ?=?0.93). An additional experiment shows that the good performing measures in this study also show high correlation with the intelligibility of single-channel noise reduced speech.     

Program equilibrium—a program reasoning approach

The concept of program equilibrium, introduced by Howard (Theory and Decision 24(3):203–213, 1988) and further formalised by Tennenholtz (Game Econ Behav 49:363–373, 2004), represents one of the most ingenious and potentially far-reaching applications of ideas from computer science in game theory to date. The basic idea is that a player in a game selects a strategy by entering a program, whose behaviour may be conditioned on the programs submitted by other players. Thus, for example, in the prisoner’s dilemma, a player can enter a program that says “If his program is the same as mine, then I cooperate, otherwise I defect”. It can easily be shown that if such programs are permitted, then rational cooperation is possible even in the one-shot prisoner’s dilemma. In the original proposal of Tennenholtz, comparison between programs was limited to syntactic comparison of program texts. While this approach has some considerable advantages (not the least being computational and semantic simplicity), it also has some important limitations. In this paper, we investigate an approach to program equilibrium in which richer conditions are allowed, based on model checking—one of the most successful approaches to reasoning about programs. We introduce a decision-tree model of strategies, which may be conditioned on strategies of others. We then formulate and investigate a notion of “outcome” for our setting, and investigate the complexity of reasoning about outcomes. We focus on coherent outcomes: outcomes in which every decision by every player is justified by the conditions in his program. We identify a condition under which there exist a unique coherent outcome. We also compare our notion of (coherent) outcome with that of (supported) semantics known from logic programming. We illustrate our approach with many examples.     

Time resolved Raman spectroscopy for depth analysis of multi‐layered mineral samples

Time resolved Raman spectroscopy (TRRS) can provide subsurface information from multi‐layered samples of transparent and translucent evaporative and silicate minerals up to several centimetres thick. Depth information was obtained using 3‐ps pulsed laser excitation at 720 nm and a gated intensified charge‐coupled device detector with stepwise increasing delay times. Blocks of different minerals were used as first, second or third layers, and Raman spectra from deeper layers could be detected through 10 mm of translucent calcite and up to 40 mm of transparent halite crystals. Measurements by conventional confocal Raman, as well as spatially offset Raman spectroscopy were also successful in distinguishing different mineral layers. This study establishes the great potential for the use of Raman spectroscopy in future planetary exploration, where TRRS could be used as a non‐invasive tool for profiling the (sub‐)surface at millimetre‐depth resolution. Copyright © 2013 John Wiley & Sons, Ltd.     

Influence of multivalent ions on power production from mixing salt and fresh water with a reverse electrodialysis system

Reverse electrodialysis is a membrane-based technique for production of sustainable electricity from controlled mixing of a diluted electrolyte solution (e.g., river water) and a concentrated electrolyte solution (e.g., sea water). Reverse electrodialysis has been investigated with pure sodium chloride solutions. In practice, however, in most cases also other ions are present in both feed solutions. In the present paper, the effect of multivalent ions on the performance of a reverse electrodialysis stack was investigated. Results show that, besides a higher stack resistance in presence of multivalent ions, especially the presence of multivalent ions in the dilute solution has a lowering effect on the stack voltage. This can be explained by an observed transport of these ions from the diluted electrolyte solution to the concentrated electrolyte solution. In order to prevent or hamper this transport against the activity gradient, monovalent-selective membranes can be used. This shows indeed better results with respect to the stack voltage. Therefore, it would be beneficial to use monovalent-selective membranes in reverse electrodialysis, especially in the case of a relatively high content of multivalent ions in the dilute (i.e., in the first stages of the installation where the sodium chloride content in the dilute is still relatively low).     

Interpretation of the asymmetrical ESR hyperfine spectrum of sodium pyrazine [Na P] in DME in the low temperature region. Evidence for the triple ion [Na P Na]+

The ESR spectrum of Na pyrazine in DME, at temperatures below ?50°C, has been studied in detail. It is shown that two paramagnetic species with slightly different g values are present in the solution, i.e. the sodium pyrazine ion pair [Na P] and the iriple ion [Na P Na]⁺. The interpretation is based on the concentration dependence of the spectrum.