Bowen Measure From Heteroclinic Points

We present a new construction of the entropy-maximizing, invariant probability measure on a Smale space (the Bowen measure). Our construction is based on points that are unstably equivalent to one given point, and stably equivalent to another: heteroclinic points. The spirit of the construction is similar to Bowen's construction from periodic points, though the techniques are very different. We also prove results about the growth rate of certain sets of heteroclinic points, and about the stable and unstable components of the Bowen measure. The approach we take is to prove results through direct computation for the case of a Shift of Finite type, and then use resolving factor maps to extend the results to more general Smale spaces

K-Theoretic Duality for Hyperbolic Dynamical Systems

The K-theoretic analog of Spanier-Whitehead duality for noncommutative C*-algebras is shown to hold for the Ruelle algebras associated to irreducible Smale spaces. This had previously been proved only for shifts of finite type. Implications of this result as well as relations to the Baum-Connes conjecture and other topics are also considered.Comment: 36 page

Electrolytic pretreatment unit gaseous effluent conditioning

The electrolytic pretreatment of urine is an advanced process that eliminates the need for handling and storing the highly corrosive chemicals that are normally used in water reclamation systems. The electrolytic pretreatment process also converts the organic materials in urine to gases (N2 and O2) that can be used to replenish those lost to space by leakage, venting, and air lock operations. The electrolytic process is more than a pretreatment, since it decreases the urine solids content by approximately one third, thus reducing the load and eventual solids storage requirements of the urine processing system. The evolved gases from the pretreatment step cannot, however, be returned directly to the atmosphere of a spacecraft without first removing several impurities including hydrogen, chlorine, and certain organic compounds. A treatment concept was developed that would decrease the impurities in the gas stream that emanates from an electrolysis unit to levels sufficiently low to allow the conditioned gas stream to be safely discharged to a spacecraft atmosphere. Two methods were experimentally demonstrated that can accomplish the desired cleanup. The bases of the two methods are, repectively: (1) raw urine scrubbing and (2) silica gel sorption

Education and Social Capital

Education is usually the most important predictor of political and social engagement. Over the last half century, educational levels in the United States have risen sharply, yet levels of political and social participation have not. Norman Nie, Jane Junn, and Kenneth Stehlik-Barry (NJS-B) have offered an elegant resolution to this paradox based on a distinction between the relative education having positive effects on participation. Using a broad range of evidence, including the data used by NJS-B, this paper shows that increases in average education levels improve trust and do not reduce participation levels. The contrast with the NJS-B participation results is found to be due to the definition of the educational environment. We use a changing regional comparison group, theoretically preferable to NJS-B's static national measure. Our results point to a more optimistic conclusion about the consequences of increases in average education levels, while leaving open the puzzle of sluggish participation.

Education and Social Capital

Education is usually the most important predictor of political and social engagement. Over the last half Century, educational levels in the United States have risen sharply, yet levels of political and social participation have not. Norman Nie, Jane Junn and Kenneth Stehlik-Barry (NJS-B) have offered a resolution to this paradox based on the distinction between absolute and relative education, with only relative education having positive effects on education. Using a broad range of data, including that used by NJS-B, this paper shows that increases in average education levels increases trust and does not reduce average participation levels. These results are found when we use a dynamic regional comparison group, theoretically preferable to NJS-B’s static national measure. Our results provide an optimistic conclusion about the effects of increases in education levels, while leaving open the explanation of declining participation levels. Our results suggest that exposure to television during childhood may play an important role in that story.