The determination of psilocin and psilocybin in hallucinogenic mushrooms by HPLC utilizing a dual reagent acidic potassium permanganate and tris(2,2´-bipyridyl)ruthenium(II) chemiluminescence detection system

This paper describes a procedure for the determination of psilocin and psilocybin in mushroom extracts using high-performance liquid chromatography with postcolumn chemiluminescence detection. A number of extraction methods for psilocin and psilocybin in hallucinogenic mushrooms were investigated, with a simple methanolic extraction being found to be most effective. Psilocin and psilocybin were extracted from a variety of hallucinogenic mushrooms using methanol. The analytes were separated on a C₁₂ column using a (95:5% v/v) methanol:10 mM ammonium formate, pH 3.5 mobile phase with a run time of 5 min. Detection was realized through a dual reagent chemiluminescence detection system of acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II). The chemiluminescence detection system gave improved detectability when compared with UV absorption at 269 nm, with detection limits of 1.2 × 10⁻⁸ and 3.5 × 10⁻⁹ mol/L being obtained for psilocin and psilocybin, respectively. The procedure was applied to the determination of psilocin and psilocybin in three Australian species of hallucinogenic mushroom.

Inverse opal gas sensors : Zn(II)-doped tin dioxide systems for low temperature detection of pollutant gases

Focusing here on the effects of zinc doping in a nanocrystalline matrix of tin dioxide, inverse opal prototype sensors are presented and extensively studied as superior candidates for gas sensing applications. Courtesy of factors including controlled porosity, enhanced surface to volume ratio and homogeneous dispersion of species in the crystalline lattice assured by the sol–gel technique, prototype sensors were prepared with high dopant ratios in a range of new compositions. Exploiting their high sensitivities to low-gas concentrations at low working temperatures, and thanks to the presented templated sol–gel approach, the prepared sensors open up new frontiers in compositional control over the sensing oxide materials, consequently widening the possibilities available in on-demand gas sensor synthesis.

Electrospun spinel LiNi0.5Mn1.5O4 hierarchical nanofibers as 5 v cathode materials for lithium-ion batteries

Spinel LiNi0.5Mn1.5O4 hierarchical nanofibers with diameters of 200–500 nm and lengths of up to several tens of micrometers were synthesized using low-cost starting materials by electrospinning combined with annealing. Well-separated nanofiber precursors impede the growth and agglomeration of Li-Ni0.5Mn1.5O4 particles. The hierarchical nanofibers were constructed from attached LiNi0.5Mn1.5O4 nanooctahedrons with sizes ranging from 200 to 400 nm. It is proven that these Li-Ni0.5Mn1.5O4 hierarchical nanofibers exhibit a favorable electrochemical performance. At a 0.5C (coulombic) rate, it shows an initial discharge capacity of 133 mAhg_1 with a capacity retention over 94% after 30 cycles. Even at 2, 5, 10, and 15C rates, it can still deliver a discharge capacity of 115, 100, 90, and 80 mAhg_1, respectively. Compared with self-aggregated nanooctahedrons synthesized using common sol–gel methods, the LiNi0.5Mn1.5O4 hierarchical nanofibers exhibit a much higher capacity. This is owing to the fact that the self-aggregation of the unique nanooctahedron-in-nanofiber structure has been greatly reduced because of the attachment of nanopolyhedrons in the long nanofibers. This unique microstructured cathode results in the large effective contact areas of the active materials, conductive additives and fully realize the advantage of nanomaterial-based cathodes.

A shareholder’s contractual right to a dividend and a company’s oppressive conduct in withholding dividend payments: Sumiseki Materials Co Ltd v Wambo Coal Pty Ltd

Traditionally, a shareholder’s expectation of receiving a dividend has been limited by the discretion the board of directors has to recommend the appropriate amount of payment as a dividend. As a general rule, shareholders will only be entitled to a dividend after the dividend is declared (normally, at the general meeting), or when the actual date arrives for the dividend to be paid. Because courts were traditionally reluctant to interfere with the internal management of companies, the remedies available to shareholders to compel a company to declare a dividend were very limited. As a result, if the directors have decided to withhold dividend payment, courts will only make an order requiring dividends to be paid under very exceptional circumstances. In this article, the authors discuss the case of Sumiseki Materials Co Ltd v Wambo Coal Pty Ltd [2013] NSWSC 235, which is exceptional for the court’s recognition of a shareholder’s contractual right to a dividend. The article analyses the court’s approach, which found that withholding dividend payments was oppressive and unfairly prejudicial conduct of the company. It also discusses the significance of shareh9olders entrenching their rights in a company’s constitution, irrespective of the fact that a company has a statutory right to alter its constitution by way of a special resolution.

Developments in machining of stacked materials made of CFRP and titanium/aluminum alloys

The aim of this article is to investigate the drilling of carbon fiber-reinforced plastic (CFRP) composite/metal stack-ups to have a details picture of the developments in this complex area. The forces and torque, chip shape, surface finish and geometry, and tool material and tool wear for drilling composite/metal stack-ups have been analyzed in details in addition to drilling mechanism of CFRP. The relation between input and output parameters was discussed and the trend of input parameters for damage free and tight tolerance holes has been investigated based on the literature. The main findings are (i) heat, built-up edge and chips generated from drilling of metallic layers damages CFRP surface, (ii) order of material layers affects the drilling outcomes significantly, (iii) coatings and step-shape on the cutting tool improves the tool performance, (iv) tool materials should be selected based on the material of metallic layer, (v) chipping, adhesion, abrasion and attrition are main tool wear mechanisms during machining of CFRP/metal stacks and (vi) application of coolant improves the machinability.