Laboratory practicals are used throughout science and engineering education as it allows students to undertake active learning and develop technical skills. It is therefore important that students arrive to these sessions as prepared as possible to maximise their learning potential. This paper analyses how student preparation affects how prepared they feel to undertake a laboratory practical. It also examines how pre-laboratory video material can affect this preparedness and student marks. Data on student preparedness and preparation is collected via surveys over three years of the same module. Data on video views and retention are collected from YouTube. Findings indicate that students' preparedness increases with time spent preparing, up to a plateau level where further preparation has little affect. Students who watch the pre-laboratory videos increase their preparedness and also increase their assessment mark. Guidelines for creating successful pre-activity videos have been developed and shown to be effective.

Gas-liquid multi-phase processes are widely used for reactions such as oxidation and hydrogenation. There is a trend for such processes to increase the productivity of the reactions, one method of which is to increase the gas flow rate into the vessel. This means that it is important to understand how these reactors perform as high gas flow rates occurs well into the heterogeneous regime. This paper investigates the mixing performance for the dual axial radial agitated vessel of 0.61 m in diameter. 6 blade disk turbine (Rushton turbine) below a 6 Mixed flow Up-pumping and down-pumping have been studied at very high superficial gas velocities to understand the flow regimes operating at industrial conditions. Electrical Resistance Tomography have been used to produce the 3D images using Matlab, along with analysing the mixing parameters such as Power characteristics, gas holdup and dynamic gas disengagement. Minimal difference between the two configurations have been reported in terms of gas holdup , however with the choice of upward and downward pumping impeller power characteristics show significant difference at very high gas flow rates. Also at these high superficial gas velocities, this report introduces a 3rd bubble class, as seen in dynamic gas disengagement experiments, which corresponds to very large slugs of gas. Highlights  At high gas flow rates, a maximum holdup is observed  Power for 6MFD/6MFU problematic at high gas flow rates  The gas liquid holdup results show minimal difference between the two configurations  Large slugs observed as a third bubble classes at very high gas flow rates Keywords Gas-liquid mixing; Gas HoldUp ; Gassed Power; Heterogeneous regime; Axial-radial dual system; Electrical Resistance Tomography V Volume [m 3 ] Volume of dispersion [m 3 ] Volume of liquid [m 3 ] Volume of gas [m 3 ] Superficial gas velocity [m s-1 Greek symbols Gas Holdup [%] Specific total energy input per liquid mass [W kg-1 ] Σ Conductivity (normalised) [mS cm-1 ] Density of fluid [kg m 3 ] Dimensionless numbers

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