The Influence of Concentration and Temperature on the Formation of γ-Oryzanol + β-Sitosterol Tubules in Edible Oil Organogels

The gelation process of mixtures of γ-oryzanol and sitosterol structurants in sunflower oil was studied using light scattering, rheology, and micro-scanning calorimetry (Micro-DSC). The relation between temperature and the critical aggregation concentration (CAC) of tubule formation of γ-oryzanol and sitosterol was determined using these techniques. The temperature dependence of the CAC was used to estimate the binding energy and enthalpic and entropic contribution to the tubular formation process. The binding energy calculated at the corresponding temperatures and CACs were relatively low, in order of 2 RT (4.5 kJ mol−1), which is in accord with the reversibility of the tubular formation process. The formation of the tubules was associated with negative (exothermic) enthalpy change (ΔH0) compared with positive entropy term (−T ΔS0 >0), indicating that the aggregation into tubules is an enthalpy-driven process. The oryzanol–sitosterol ratio affected the aggregation process; solutions with ratio of (60 oryzanol–40 sitosterol) started aggregation at higher temperature compared with other ratios

Solvent contribution to the stability of a physical gel characterized by quasi-elastic neutron scattering

The dynamics of a physical gel, namely the Low Molecular Mass Organic Gelator {\textit Methyl-4,6-O-benzylidene-$\alpha$ -D-mannopyranoside ($\alpha$-manno)} in water and toluene are probed by neutron scattering. Using high gelator concentrations, we were able to determine, on a timescale from a few ps to 1 ns, the number of solvent molecules that are immobilised by the rigid network formed by the gelators. We found that only few toluene molecules per gelator participate to the network which is formed by hydrogen bonding between the gelators' sugar moieties. In water, however, the interactions leading to the gel formations are weaker, involving dipolar, hydrophobic or $\pi-\pi$ interactions and hydrogen bonds are formed between the gelators and the surrounding water. Therefore, around 10 to 14 water molecules per gelator are immobilised by the presence of the network. This study shows that neutron scattering can give valuable information about the behaviour of solvent confined in a molecular gel.Comment: Langmuir (2015

On the segmented rotor reluctance synchronous motor saliency ratio calculation

The reluctance synchronous motor performance highly depends on its saliency ratio. Therefore an accurate analytical calculation of the motor’s saliency is quite a necessity within the designing procedure. In this paper an analytical method to calculate the main motor inductances and its saliency ratio is applied to a segmented rotor reluctance synchronous motor. The results obtained for two motor variants, compared with the ones obtained via a 2-D FEM computation and via tests, stand by to prove the proposed technique accuracy