However, below 80◦C, in the temperature range of 80–75◦C,gel formation was observed, resulting in the gradual increase of the outlet Tc-w to 3–4◦C, while the inlet Tc-w was a t 8–10◦C. After the formation of the thick gel layer at the tube wall, as reported during the first experiment, very low impact was observed from vibration effects, with the outlet Tc-w remaining at the same value with or without vibration, with an approximate improvement of 1–3◦C due to vibration.