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- Author or Editor: M. Paul x
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Abstract
Phosphorous pentasulfide is an important starting material for a number of commercial chemicals. Examples include lubricant additives (Spikes, Trib Lett 17:469–489, 2004), agricultural insecticides (Kirk-Othmer, Enycl Chem Technol 14:549–552, 1995), and mining ore flotation agents. Phosphorous pentasulfide is a mixture of several components, one of which is free elemental sulfur, present at levels of approximately 50 ppm to 20,000 ppm (2 %). The amount of free sulfur present in the phosphorous pentasulfide can impact manufacturing, such as zinc dithiosulfate processing. Therefore, an accurate and fast analytical method to measure elemental sulfur in phosphorous pentasulfide would be of value compared to what is available now.
Abstract
The usual determination of formaldehyde by gravimetry and spectroscopy extends down to 10−3 mg with only limited reproducibility. Radiochemical analysis using14C-labelled formaldehyde allows to determine amounts of 10−4 to 10−5 mg. This technique was, therefore, applied to detect reliably the amount of formaldehyde proportional to the activity in viscose rayon, spun in a formaldehyde containing spinning bath by using an ionisation chamber assay. The objects investigated were found to contain 2·10−5 mg to 1.4·10−4 mg formaldehyde, the relative error being lower than 4%. The scope of application of this method is discussed.
Herein, we illustrate how microreactor technology can be used as a tool for reaction screening and optimization, in addition to improving the reaction chemistry. We report the in-situ generation of azo compounds by reactive quenching of diazonium intermediates in microreactors. This involves an electrophilic aromatic substitution reaction, namely, an azo-coupling reaction performed in continuous-flow systems in the presence of a phase transfer catalyst with great emphasis on compounds that do not easily couple. Capitalizing on the benefits of a large surface area and the short molecular diffusion distances observed in microreactors, in-situ phase transfer catalyzed azo-coupling reaction of diphenylamine to p-nitroaniline was investigated. A rapid and easy optimization protocol was established which yielded a 99%, 22%, and 33% conversion of diphenylamine, carbazole, and triphenylamine, respectively, in approximately 2.4 min.
Abstract
The preparation of magnetic iron oxide nanoparticles within microreactors is reported. The proportion of γ-Fe2O3 and Fe3O4 in the sample was determined, an important parameter for reproducibility in applications.
In this perspective article, the use of continuous flow synthesis to prepare advanced pharmaceutical intermediates in developing economies is highlighted. Case studies are presented to suggest that cost effective local manufacture of life saving drugs, may potentially be implemented to facilitate better access to drugs to the underprivileged.
Background and aims
Social casino games (SCGs) feature gambling themes and are typically free to download and play with optional in-game purchases. Although few players spend money, this is sufficient to make them profitable for game developers. Little is known about the profile and motivations of paying players as compared to non-paying players.
Methods
This study compared the characteristics of 521 paying and non-paying Australian social casino game players who completed an online survey.
Results
Paying players were more likely to be younger, male, speak a non-English language, and have a university education than non-payers. Paying players were more likely to be more highly involved in SCG in terms of play frequency and engagement with games and emphasized social interaction more strongly as a motivation for playing. A cluster analysis revealed distinct subgroups of paying players; these included more frequent moderate spenders who made purchases to avoid waiting for credits and to give gifts to friends as well as less frequent high spenders who made purchases to increase the entertainment value of the game.
Discussion
These findings suggest that paying players have some fundamental differences from non-paying players and high spenders are trying to maximize their enjoyment, while non-spenders are content with the game content they access.
Conclusions
Given the structural similarities between SCG and online gambling, understanding subgroups of players may have broader implications, including identifying characteristics of gamers who may also engage in gambling and players who may develop problems related to excessive online gaming.
Background and Aims
Gambling and gaming activities have become increasingly recognised as sharing many common features at a structural and aesthetic level. Both have also been implicated as contributing to harm through excessive involvement. Despite this, relatively little attention has been given to the fundamental characteristics that differentiate these two classes of activity, especially in situations where the boundaries between them may be particularly hard to distinguish. This is evident, for example, in digital games that incorporate free and paid virtual currencies or items, as well as the capacity for wagering. Such overlaps create problems for regulatory classifications, screening, diagnosis and treatment. Is the problem related to the gambling or gaming content?
Methods
In this paper, we review the principal sources of overlap between the activity classes in terms of several dimensions: interactivity, monetisation, betting and wagering, types of outcomes, structural fidelity, context and centrality of content, and advertising.
Results
We argue that gaming is principally defined by its interactivity, skill-based play, and contextual indicators of progression and success. In contrast, gambling is defined by betting and wagering mechanics, predominantly chance-determined outcomes, and monetisation features that involve risk and payout to the player. A checklist measure is provided, with practical examples, to examine activities according to features of design and function, which may inform guidelines for policy makers, researchers and treatment providers.
Discussion and conclusions
We suggest that, in some instances, using category-based nomenclature (e.g., “gambling-like game”) may be too vague or cumbersome to adequately organise our understanding of new gaming/gambling hybrid activities.
Abstract
Hydrazoic acid (HN3) was used in a safe and reliable way for the synthesis of 5-substitued-1H-tetrazoles and for the preparation of N-(2-azidoethyl)acylamides in a continuous flow format. Hydrazoic acid was generated in situ either from an aqueous feed of sodium azide upon mixing with acetic acid, or from neat trimethylsilyl azide upon mixing with methanol. For both processes, subsequent reaction of the in situ generated hydrazoic acid with either organic nitriles (tetrazole formation) or 2-oxazolines (ring opening to β-azido-carboxamides) was performed in a coil reactor in an elevated temperature/pressure regime. Despite the explosive properties of HN3, the reactions could be performed safely at very high temperatures to yield the desired products in short reaction times and in excellent product yields. The scalability of both protocols was demonstrated for selected examples. Employing a commercially available benchtop flow reactor, productivities of 18.9 g/h of 5-phenyltetrazole and 23.0 g/h of N-(1-azido-2-methylpropan- 2-yl)acetamide were achieved.
A highly scalable and efficient flow-system has been developed to perform the catalyzed acetylation of alcohols and phenols, such as salicylic acid, at room temperature in excellent yield. The volumetric throughput and the amount of product can be increased simply by increasing the diameter of a versatile catalytic 12-tungstosilicic acid-supported, silica monolith can be used to increase the quantity of product produced without having to changeing the optimal operatingreaction conditions.
