Observing the Mpemba effect with minimal bias and the value of the Mpemba effect to scientific outreach and engagement

The Mpemba effect is the assertion that it is quicker to cool or freeze water when the initial temperature is high. We define the Mpemba effect to have been observed when two samples of water, one initially warmer than the other, are cooled and the initially hotter sample freezes or cools to a prescribed temperature in less time; this assumes that the samples are of the same mass, are at least as pure as drinking water, the cooling is delivered to both samples in the same manner and the same level of insulation is applied to both. Under this definition, we enable repeatable observations of the Mpemba effect by systematically introducing increased nucleation sites (in our case by roughening the container walls with sandpaper) within the cooling environment of the initially warmer sample. We remain able to observe the Mpemba effect when the enthalpy of cooling and freezing the initially warmer sample exceeds that of the initially cooler sample by over 50%, corresponding to a difference in the initial temperatures of around 50 °C. The context of this study, initiated by a high-school student who then carried out all of the experiments, highlights the value of the Mpemba effect as a tool for scientific learning and engagement.

Limber tail syndrome in German shepherd dog

A 3-year-old intact female German shepherd dog weighing 25 kg was evaluated for acute onset of staggering gait and flaccid (dropped) tail following immersion in freeze water. Clinical signs included staggering gait, aggressive behavior, postural pain and flaccid tail. Clinical signs progressed in severity for 2-3 hours following immersion in freeze water. The dog was treated using anti-inflammatory medication along with warm fomentation of the affected portion of the tail and complete rest. Dog uneventfully recovered on day 7 of initiation of treatment and no reoccurrence was observed during one month follow up period. Limber tail syndrome is an uncommonly reported condition in German shepherd dogs that should be considered when sudden staggering gait and dropped tail is observed after immersion in too cold water. Recovery is possible with anti-inflammatory drugs and rest.

Uing DSC Technology for Water Content and Thermal Properties Analysis of Carassius Organs

Thermal properties of Brain, gill, hepatopancreas, muscle and blood of Carassius living in 8°C were investigated by differential scanning calorimeter. Between 20°C～-40°C , blood showed lower specific heat capacity than other organs. It might help temperature equilibrium in organism. Blood and brain had higher freezing temperature. Brain showed the maximum water content but less freeze water while ventral muscle had the lowest water content but high freeze-able water. Hepatopancreas had both low water and freeze-able water content.