Background: Informed consent dictates that patients appreciate the risks and benefits of imaging techniques that use ionizing radiation. Computed tomography (CT) and X-ray carry a stochastic lifetime risk of inducing malignancy. This risk is difficult to convey and often overlooked. Objective: This work aims to establish some basics regarding patient knowledge and perception of medical imaging to facilitate an informed consent process. Method: A questionnaire survey was conducted in a general orthopedic outpatient clinic in a United Kingdom tertiary center. Results: There were 219 respondents. Twenty-two percent understood that CT produces ionizing radiation associated with cancer risk, but only 6% knew about cancer risk from natural background radiation. Only 25% knew that CT has a higher cancer risk than X-ray. The majority (93%) knew that smoking poses higher risk than X-rays. The Internet as an information source was statistically associated with concern about X-rays. Conclusions: Patients underestimated CT cancer risk and were unable to compare risk between imaging modalities. Risk can be more effectively conveyed using better known relatable risks as comparators. Patient groups associated with lower knowledge, most in need of education, were highlighted.

A comprehensive model for emulsion polymerisation is presented, accounting for particle size distribution (PSD) and molecular weight distribution (MWD). The PSD information is incorporated through a population balance framework. A mechanistic formulation is adopted in modelling the average number of radicals/particle under pseudo‐bulk compartmentalisation conditions. The method of moments is adopted to simplify the MWD equations over each discrete size class. The impact of the pseudo‐bulk assumption on the PSD and MWD results is assessed. An identification of potential manipulated variables for control of PSD and MWD is done through sensitivity analysis.

A sensitivity study of particle size distribution (PSD) and molecular weight distribution (MWD) responses to perturbations in initiator, surfactant, monomer and chain transfer agent in a semi‐batch emulsion polymerisation is presented. The objective is to provide a systematic study on the ability to simultaneously control both PSD and MWD, towards inferential control of end‐use product properties. This would lead towards identification of the practical feasible regions of operability. All inputs appeared to have an intrinsic and simultaneous influence on end‐time PSD and MWD. Trends shown in experimental results have been explained in a mechanistic sense and also compared to simulation results from a combined PSD/MWD population balance model. The preliminary comparison between experiment and simulation highlights areas to be focussed on with respect to model improvement.

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