Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys

Thermodynamic properties of selected honeys: glass transition temperature (Tg), the change in specifi c heat capacity (ΔCp), and enthalpy (ΔH) were analysed using differential scanning calorimetry (DSC) in relation to the composition i.e. water and sugar content. Glass transition temperatures (Tg) of various types of honey differed significantly (p<0.05) and ranged from -49.7°C (polyfloral) to -34.8°C (sunflower). There was a strong correlation between the Tg values and the moisture content in honey (r = -0.94). The degree of crystallisation of the honey also influenced the Tg values. It has been shown that the presence or absence of sugar crystals influenced the glass transition temperature. For the decrystallised honeys, the Tg values were 6 to 11°C lower than for the crystallised honeys. The more crystallised a honey was, the greater the temperature difference was between the decrystallised and crystallized honey. In conclusion, to obtain reliable DSC results, it is crucial to measure the glass transition after the complete liquefaction of honey.

Wood liquefaction by ionic liquids

The liquefaction of wood (Metasequoia glyptostroboides) has been studied in two imidazole-based ionic liquids: IL1, 3,3′-ethane-1,2-diylbis(1-methyl-1H-imidazol-3-ium) dichloride; and IL2, 3,3′-ethane-1,2-diylbis(1-methyl-1H-imidazol-3-ium) dichloroaluminate. Rapid and complete liquefaction was obtained in IL2 without residue at 120°C for 25 min, in contrast to liquefaction in phenol/H2SO4 (liquid/wood ratio 20:1) with 25.9% residue. Temperature- and time-dependent studies indicate that the performance of the reagents investigated is IL2>IL1> phenol/H2SO4. The liquid/wood ratio and the amount of AlCl3 as catalyst affect the liquefaction rate. In the course of liquefaction with IL2, AlCl3 plays a dual role as a catalyst and a liquefaction reagent. Ionic liquids separated from the liquefied product can be recycled at least five times to maintain a good liquefaction rate.

The Saint-Jean-Vianney Landslide: Observations and Eyewitnesses Accounts

A major landslide occurred in Champlain Clay at Saint-Jean-Vianney, Quebec, on May 4, 1971. Preliminary investigations reveal that the slide commenced about 10.15 p.m., hit the east section of the town about 10.55 p.m., and within 5 min carried 40 homes to destruction and 31 persons to their deaths. An estimated 9 × 106 cubic yards (6.9 × 108 m3) of material moved during the slide, from an area of approximately 350 000 square yards (~268 000 m2). The slide commenced within the crater of a much larger landslide that occurred about 500 years ago, and after complete liquefaction travelled down the Rivière aux Vases at a speed of approximately 16 miles/h (~26 km/h), carrying debris out into the middle of the Saguenay River.A detailed geotechnical study of the landslide region is currently under way.