Explicit Solution to a Certain Non-ELQG Risk-sensitive Stochastic Control Problem

A risk-sensitive stochastic control problem with finite/infinite horizon is studied with a 1-dimensional controlled process defined by a linear SDE with a linear control-term in the drift. In the criterion function, a non-linear/quadratic term is introduced by using the solution to a Riccati differential equation, and hence, the problem is not ELQG (Exponential Linear Quadratic Gaussian) in general. For the problem, optimal value and control are calculated in explicit forms and the set of admissible risk-sensitive parameters is given in a concrete form. As applications, two types of large deviations control problems, i.e., maximizing an upside large deviations probability and minimizing a downside large deviations probability, are mentioned.     

Oxidative heck-type reaction involving cleavage of a carbon-phosphorus bond of arylphosphonic acids

Cleavage of a carbon-phosphorus bond is achieved under palladium catalysis in an oxidative Heck-type reaction which exploits arylphosphonic acids. The reaction of arylphosphonic acids with alkenes provides arylation products in good yields in the presence of TBAF with trimethylamine oxide as an oxidant.     

Binding assay for cholera toxin based on sequestration electrochemistry using lactose labeled with an electroactive compound

A simple electrochemical binding assay for cholera toxin (CT) was developed using lactose labeled with daunomycin as an electroactive compound. The labeled lactose (LL) was determined with high sensitivity by adsorptive stripping voltammetry (AdSV). The electrochemical behaviors of LL at glassy carbon (GC), plastic formed carbon (PFC) and carbon nanotubes paste (CNTP) electrode were investigated. The CNTP electrode showed the greatest accumulation capacity for LL. The assay for CT based on the sequestration electrochemistry was demonstrated. The binding event of the LL to CT was detected by the decrease in the electrochemical response of daunomycin as an electroactive label without a separation process to remove the free LL from the one bound with CT before any measurements can be made. The detection limit of the CT assay using the CNTP electrode was 0.5 nM (42 ng mL(-1)).     

Radiation-induced postpolymerization of trioxane in the solid state. IV. Copolymerization of trioxane with dioxolane

The radiation-induced postpolymerization of trioxane with 1,3-dioxolane has been investigated. Trioxane and 1,3-dioxolane were carefully purified in a rigorously dry, high-vacuum system. In the present study it was found that trioxane can be easily copolymerized with 1,3-dioxolane to give a copolymer having high molecular weight and excellent thermal stability. Typically, the isothermal weight loss after heating for 60 minutes under nitrogen at 222°C was 3.5% for a copolymer of trioxane and 1.0 wt-%1,3-dioxolane preirradiated with a dose of 1.0 × 10⁵ Rad. The thermal stability of the copolymer was scarcely affected by the polymerization temperature and time, although it decreased slightly with increasing preirradiation dose. The dependences of the yield and inherent viscosity of the polymer on the preirradiation dosage, polymerization temperature and time were quite similar to those found for the homopolymerization of trioxane. The results were analyzed by using the kinetic scheme previously reported, and it was found that no chain transfer reaction occurs in this system. These results are discussed in comparison with those of homopolymerization reported previously.     

X-ray fluorescence spectrometric determination of sulfur-containing anionic surfactants in water after their enrichment on a membrane filter as an ion-pair complex with a cationic surfactant.

Anionic surfactants containing sulfur in their structure were enriched on a mixed cellulose ester membrane filter (MF) by filtration as an ion-pair complex with a cationic surfactant. After their enrichment, the anionic surfactants were determined by X-ray fluorescence spectrometry of the sulfur enriched on the MF. A linear calibration was obtained over a concentration range from 0.05 to 0.8 mg L(-1) of sodium dodecyl sulfate as a standard material with less than 6% RSD. The detection limit based on 3s for the reagent blank was 2 microg L(-1). This method is very simple, rapid and highly selective for sulfur-containing surfactants, and does not require any organic solvent extraction. This method was applied to the determination of anionic surfactant in some urban river waters where domestic wastewater was discharged. The results were compared with those obtained by conventional solvent extraction-spectrophotometry. The distribution of the analyte complexes within the MF where the ion-pair was retained is also discussed.