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

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

What\u27s Wrong with Involuntary Manslaughter?

Efforts to explain when and why the state can legitimately impose retributive punishment on an actor who inadvertently creates an unjustified risk of causing death (and death results) typically rely on one of two theories. The prior-choice theory claims that retributive punishment for inadvertent lethal risk-creation is justified if and only if the actor\u27s inadvertence or ignorance was a but-for and proximate result of a prior culpable choice. The hypothetical-choice theory claims that retributive punishment for inadvertent lethal risk-creation is justified if and only if the actor would have chosen to take the risk if he had been aware of it, even though he was not in fact aware of it. I argue that neither of these theories satisfactorily identifies when and why retributive punishment is warranted for inadvertent lethal risk-creation. Instead, I propose that an actor who creates a risk of causing death but who was unaware of that risk can fairly be subject to retributive punishment if he was either non-willfully ignorant or self-deceived, and if such ignorance or self-deception was due to the causal influence of a desire he should have controlled. The culpability of such an actor consists, not in any prior actual choice to do wrong, nor in any imagined hypothetical choice to do wrong, but in the culpable failure to exercise doxastic self-control: control over one\u27s beliefs