A Neutral-Beam Injector for the Tandem-Mirror Fusion Reactor Delivering 147 MW of 1.2-MeV D°

A conceptual design of a high-current, 1.2-MeV Do injector is presented. This injector has an anticipated operating efficiency of 73%. Major advances in beam technology are needed to meet these specifications, including a continuous source of negative ions, an efficient electron-stripping cell, and the development of associated power conditioning and control equipment. All components in the proposed beam line are elaborations of physics experiments already reported in the literature; therefore, it should be possible to satisfy the neutral-beam requirements of the tandem-mirror reactor (TMR) in the not too distant future.     

Iridium‐Catalyzed Enantioselective Allylic Alkylation with Functionalized Organozinc Bromides

Iridium‐catalyzed enantioselective allylic alkylation of branched racemic carbonates with functionalized alkylzinc bromide reagents is described. Enabled by a chiral Ir/(P,olefin) complex, the method described allows allylic substitution with various primary and secondary alkyl nucleophiles with excellent regio‐ and enantioselectivities. The developed reaction was showcased in a concise, asymmetric synthesis of (?)‐preclamol.     

Luminescence excitation spectra of toluene and mesitylene in rare-gas matrices

Total luminescence yield of toluene and mesitylene, isolated in rare-gas matrices, has been measured as a function of excitation energy in the energy range covering the absorption region of both host and guest. Energy transfer from the host to the dopant is apparent. An increase in the luminescence yield is observed at the host exciton state. Luminescence excitation spectrum of pure mesitylene is presented.     

Local Strain Concentrations in a Microvascular Network

Strain concentrations associated with the presence of a microvascular network in a polymer matrix are measured using fluorescent digital image correlation (FDIC). The accuracy of the measurement technique is established for a specimen containing only a single microchannel. The influence of localized particle reinforcement around the channel is also investigated using this simplified geometry. Three-dimensional network specimens with different structural designs were fabricated and loaded in uniaxial tension. The resulting strain concentrations are compared as a function of channel spacing and location. As expected, decreasing channel spacing leads to increased strain local to the channels. In addition, the three-dimensional nature of the channel architecture influences the resulting strain. The results provide insight into the mechanical behavior of microvascular networks and demonstrate the utility of FDIC as a characterization tool at these length scales.     

IIPS: A framework for specifying inductive-inference problems

We propose the IIPS framework for specifying inductive inference problems. Unlike the specification outline given in [1], the IIPS framework is formally defined and can specify problems where the inducer influences the presentation order of the examples. The framework is suited to specifying machine-discovery problems.     

Absolutely continuous conjugacies of Blaschke products III

Research supported in part by the National Science Foundation.