Whipped oil stabilised by surfactant crystals

We describe a protocol for preparing very stable air-in-oil foams starting with a one-phase oil solution of a fatty acid (myristic acid) in high oleic sunflower oil at high temperature. Upon cooling below the solubility limit, a two-phase mixture consisting of fatty acid crystals (length around 50 μm) dispersed in an oil solution at its solubility is formed which, after whipping, coat air bubbles in the foam. Foams which do not drain, coalesce or coarsen may be produced either by increasing the fatty acid concentration at fixed temperature or aerating the mixtures at different temperatures at constant concentration. We prove that molecular fatty acid is not surface-active as no foam is possible in the one-phase region. Once the two-phase region is reached, fatty acid crystals are shown to be surface-active enabling foam formation, and excess crystals serve to gel the continuous oil phase enhancing foam stability. A combination of rheology, X-ray diffraction and pulsed nuclear magnetic resonance is used to characterise the crystals and oil gels formed before aeration. The crystal-stabilised foams are temperature-sensitive, being rendered completely unstable on heating around the melting temperature of the crystals. The findings are extended to a range of vegetable oil foams stabilised by a combination of adsorbed crystals and gelling of the oil phase, which destabilise at different temperatures depending on the composition and type of fatty acid chains in the triglyceride molecules

Hybrid thermocouple development program

The design and development of a hybrid thermocouple, having a segmented SiGe-PbTe n-leg encapsulated within a hollow cylindrical p-SiGe leg, is described. Hybrid couple efficiency is calculated to be 10% to 15% better than that of a all-SiGe couple. A preliminary design of a planar RTG, employing hybrid couples and a water heat pipe radiator, is described as an example of a possible system application. Hybrid couples, fabricated initially, were characterized by higher than predicted resistance and, in some cases, bond separations. Couples made later in the program, using improved fabrication techniques, exhibited normal resistances, both as-fabricated and after 700 hours of testing. Two flat-plate sections of the reference design thermoelectric converter were fabricated and delivered to NASA Lewis for testing and evaluation

Dealing with Wayward Desire

The exercise of synchronic self-control is the way in which an actor can attempt to bring a desire into alignment with his better judgement at the moment and during the interval of time over which, but for the exercise of such self-control, the desire would become the actor’s preponderant desire, which the actor would then translate into an act contrary to his better judgment. The moral psychology of an actor who fails to achieve such self-control can be analyzed in two ways. One way is meant to be consistent with compatibilist metaphysics; the other with libertarian metaphysics. The implications of these analyses for the criminal law are complicated, but perhaps the most important is this: the criminal law should in principle recognize a partial excuse for an actor who exercises synchronic self-control but who gives up his effort because he believes that he can no longer continue to resist. His effort to achieve self-control thus fails, and he ends up translating into action the very desire he set out to control

Self-Defense and the Mistaken Racist

How should the law respond when one person (D) kills another person (V), who is black, because D believes that V is about to kill him, but D would not have so believed if V had been white? Should D be exonerated on grounds of self-defense? Some commentators argue that D\u27s claim of self-defense should be rejected. He should be convicted and punished. I argue, however, that denying D\u27s claim of self-defense would be at odds with the principle that criminal liability and punishment should only be imposed on an actor if he chooses to cause or risk causing a harm when the law does not permit him to make such a choice, and not for possessing or choosing to possess racist or otherwise illiberal beliefs or desires. Moreover, insofar as this principle can fairly be characterized as one to which a liberal state must adhere, then a liberal state should acknowledge D\u27s claim of self-defense