Solid-state polymorphic transition (SSPT) has been regarded as an interesting research subject for a long time, but kinetics and the mechanism of these phase transitions are still not fully understood. Particularly, kinetic studies on the SSPT process of cocrystals are not widely reported even though extensive novel cocrystal polymorphs have been discovered over the recent decades. Herein we presented a comprehensive kinetic study of the enantiotropic polymorphic system of 1:1 nicotinamide (NA)–pimelic acid (PA) cocrystals with the combination of various analytical methods. Bulk kinetic studies conducted with powder X-ray diffraction and differential scanning calorimetry indicated that both directions of SSPT (form 1 ↔ form 2) occur by a nucleation and growth mechanism. In addition, large activation energy barriers of form 1 → form 2 with a wide range (337.1–514.2 kJ mol–1) and variations in the onset transition temperature were observed, depending on the crystal conditions. In situ atomic force microscopy analysis was also carried out to monitor the surface morphology change at the nanoscale to supplement the bulk kinetics.

This study examines the lexical representation and recall of abstract words by beginning L2 learners of Spanish in the light of the predictions of the dual coding theory (Paivio 1971; Paivio and Desrochers 1980). Ninety-seven learners (forty-four males and fifty-three females) were randomly placed in the picture or non-picture group and taught twelve concrete and twelve abstract words they did not previously know. Subjects performed a recall task on an immediate and a delayed posttest. The results showed that associating abstract words with pictures had a significant effect on their recall on the immediate posttest, but no such effect was found on the delayed posttest. The results suggest that associating abstract lexical items with pictures has a significant effect on memory representation and recall in the short term. The findings also support the predictions of the dual coding theory and show that a concreteness effect can be created for abstract words by associating them with visual images.

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