The History of Skunk Defensive Secretion Research

The striped skunk (Mephitis mephitis) is widely known for the highly odoriferous defensive secretion it uses to repel predators. Chemists have sporadically investigated the chemical composition of this secretion for many years. In this research, a number of chemicals have been incorrectly attributed to this secretion and the errors incorporated into the chemical literature. The major component in skunk spray was erroneously believed to be l-butanethiol, until it was later shown that the actual compound was (E)-2-butene-l-thiol. More recently, two studies identified the third major compound in the secretion as either (E)-2-butenyl methyl disulfide or (E)-2-butenyl propyl sulfide. These structural assignments were incorrect and the compound was later shown to be (E)-2-butenyl thioacetate. Two investigations have reported chemicals that could not be confirmed in a later study, so these compounds may have been artifacts produced during isolation or analysis. The striped skunks secretion is similar to, but different from, the defensive secretions of two other skunk species, the spotted skunk (Spilogale gracilis) and the hog-nosed skunk (Conepatus mesoleucus).Folklore asserts that tomato juice will neutralize the odor of skunk spray, but human olfactory fatigue can explain the apparent disappearance of the odor on sprayed pets. The odoriferous thiols in skunk spray can easily be neutralized by oxidation to sulfonic acids.     

A fluidized bed process for electron sterilization of powders

A small capacity (100 g.s⁻¹) pilot system is described for presentation of powders and fine aggregates at high velocity, to an electron beam. Electron beam dose rate is continuously monitored in real time, while the thickness of the fluidized bed used to pneumatically transport the product can be monitored and controlled using beta-gauge techniques. Using electron paramagnetic resonance (EPR) techniques, alanine power mixed with the product is used for precise determination of dose delivered to the powder stream. Thin film dosimeters transported in the bed are also used for dose determination. Results with a variety of products are presented using both dose rate and velocity as the independent variables. Lethality data for the bioburdens present in several powdered foodstuffs are discussed.     

Electroclinic effects in a homogeneously aligned smectic A cell

The electroclinic effect, in a material having a first order S_A to S_C* transition, is studied using the half leaky guided mode geometry. Using an approximately 1 μm thick, homogeneously aligned cell, the voltage induced director twist is characterized at a few temperatures in the S_A phase. The mean field theory readily explains the data recorded at low fields where a linear dependence on voltage is found. However, at higher fields, an unexpected saturation occurs which is most likely caused by the influence of strong surface anchoring forces.     

A Geometric formulation of the causal Interpretation of quantum mechanics

The principles of the causal interpretation are embodied in a conformally invariant theory in Weyl space. The particle is represented by a spherically symmetric thin-shell solution to Einstein's equations. Use of the Gauss-Mainardi-Codazzi formalism yields new insights into the issues of nonlocality, the quantum potential, and the guidance mechanism.1. The issue of negative probabilities associated with second-order wave equations in the causal interpretation is discussed in Ref. 19.