A review of nicotine‐containing electronic cigarettes: trends in use, effects, contents, labelling accuracy and detection methods

Electronic cigarettes (ECs) are thought to be less harmful than traditional combustible cigarettes and were originally intended to help smokers quit. Over the past two decades, they have especially gained popularity with the younger generation. To date, there are over 7000 unique e-liquid flavours available and over 400 different e-cigarette brands. The accuracy of nicotine strength labelling in e-liquids was assessed in this work. Twenty-three studies from around the world were chosen to assess the level and frequency of nicotine mislabelling in 545 e-liquid products. Nicotine strengths were most commonly mislabelled by between 5% and 20%, with the majority testing lower than what the label indicated. Fifteen European e-liquids that were assessed were labelled as 20 mg/ml or less, yet when tested, they contained more than 20 mg/ml of nicotine. One e-liquid that was supposed to contain no nicotine in fact contained 23.91 mg/ml of nicotine. Furthermore, the difference between the medians of the available labelled and experimental nicotine concentrations was significant (p < 0.001, Wilcoxon signed rank test). Preliminary studies show that high nicotine levels delivered via aerosol increase the risk for nicotine poisoning and cause airway inflammation. Other EC ingredients, such as flavourings, contribute to EVALI and ‘popcorn lung’. There is evidence that certain flavourings, such as menthol, reinforce the effects of nicotine and modify drug absorption and metabolism. There is a global need for better quality control in EC products in order to make these safe for consumers

A review of cannabidiol‐containing electronic liquids: current regulations and labelling accuracy

The use of cannabidiol in electronic liquids (e-liquids) is becoming increasingly widespread, and the current regulations enforced onto nicotine-containing e-liquids are not applicable to cannabidiol-based products. This has led to concerns about the quality of cannabidiol vapes. Articles investigating the reliability of product labelling were reviewed using systematic review criteria. Of 70 e-liquids, 77.1% of the e-liquids tested in the articles were found to have underestimated or overestimated the cannabidiol quantities stated in the product labelling. Statistical analysis confirmed that there was a significant difference between the labelled and analysed cannabidiol concentrations (p < 0.05, Mann-Whitney U and Wilcoxon Signed Rank). Inaccuracies in received cannabidiol dosages could lead to an increased risk of adverse reactions or limit the therapeutic effect received, highlighting the benefit of enforcing specific regulations on cannabidiol-based e-liquids to protect consumer safety and guarantee product efficacy

HIGH-REYNOLDS-NUMBER ASYMPTOTICS OF THE STEADY FLOW-THROUGH A ROW OF BLUFF-BODIES

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Quantifying Correlation Uncertainty Risk in Credit Derivatives Pricing

We propose a simple but practical methodology for the quantification of correlation risk in the context of credit derivatives pricing and credit valuation adjustment (CVA), where the correlation between rates and credit is often uncertain or unmodelled. We take the rates model to be Hull–White (normal) and the credit model to be Black–Karasinski (lognormal). We summarise recent work furnishing highly accurate analytic pricing formulae for credit default swaps (CDS) including with defaultable Libor flows, extending this to the situation where they are capped and/or floored. We also consider the pricing of contingent CDS with an interest rate swap underlying. We derive therefrom explicit expressions showing how the dependence of model prices on the uncertain parameter(s) can be captured in analytic formulae that are readily amenable to computation without recourse to Monte Carlo or lattice-based computation. In so doing, we crucially take into account the impact on model calibration of the uncertain (or unmodelled) parameters

A Prandtl-Batchelor model of flow in the wake of a cascade of normal flat plates

The steady large-Re flow through a cascade of normal flat plates is considered in the limit of small blockage ratio. Evidence is presented suggesting the existence of a branch of Prandtl-Batchelor solutions comprising two symmetric inviscid regions, each with constant vorticity, surrounded by thin shear layers which enable smooth matching with the external flow. The wake length is proportional to the cascade half-width. The solutions are of particular note in that they constitute non-unique solutions of the system, i.e. a bifurcated branch. The calculation requires however the postulation of an infinite sequence of small secondary vortices near the plate's rear stagnation point; elucidation of the implied structure is seen not to be possible without full Navier-Stokes computation.<br/