Spins in 23Na from 25Mg(d, α)

The ²⁵Mg(d, α)²³Na reaction has been investigated at bombarding energies of 12.07,11.82 and 11.57 MeV. Angular distributions are approximately symmetric about 90° and for states of known J^π angle-integrated cross sections $\text{σ}$ averaged over bombarding energy, are roughly proportional to $\text{2J + 1:}\text{σ}\text{/(2J + 1) = 25±4 μ}\text{b}$. Measured cross sections for other states, up to E_x = 7.9 MeV, have been used to place limits on J.     

Entire solutions of first-order nonlinear partial differential equations

We show that any entire solution of an essentially nonlinear first-order partial differential equation in two variables must be linear.

     

The Zoo Connection: A Cooperative Project Between Formal and Informal Educational Institutions

This project was a cooperative effort between university faculty, elementary school teachers, and members of the Education Department at the Indianapolis Zoo. The purpose of this project was to develop, evaluate, and disseminate a set of fourteen K-6 science lessons that could be used in conjunction with field trips to the zoo. These lessons, titled The Zoo Connection, follow the Learning Cycle teaching model. In addition to following the model, the development of the lessons was based on the premise that teachers should focus on a specific science concept or set of related concepts when visiting a zoo. Workshop sessions were conducted to introduce teachers to the materials and to provide them with strategies for implementing the materials in their science instruction. An evaluation was conducted for each workshop session to determine teachers' perceptions of the materials and to determine whether they felt prepared to use them with their students. The materials were also field-tested in several elementary schools to assess their effectiveness for presenting science concepts to elementary school children. Results indicate that teachers felt the workshops adequately prepared them to use the materials and that the materials were effective for presenting science concepts.     

Polyvinylidene fluoride-co-chlorotrifluoroethylene and polyvinylidene fluoride-co-hexafluoropropylene nanofiber-coated polypropylene microporous battery separator membranes

Nanofiber-coated polypropylene (PP) separator membranes were prepared by coating a Celgard® microporous PP membrane with electrospun polyvinylidene fluoride-co-chlorotrifluoroethylene (PVDF-co-CTFE) and PVDF-co-CTFE/polyvinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP) nanofibers. Three PVDF polymer solutions of varying compositions were used in the preparation of the nanofiber coatings. Two of the polymer solutions were PVDF-co-CTFE blends made using different types of PVDF-co-HFP copolymers. The PVDF-co-CTFE and PVDF-co-CTFE/PVDF-co-HFP blend nanofiber coatings have been found to have comparable adhesion to the PP microporous membrane substrate. The electrolyte uptakes and separator–electrode adhesion properties of nanofiber-coated membranes were evaluated. Both the electrolyte uptake and the separator–electrode adhesion were improved by the nanofiber coatings. The improvement in electrolyte update capacity is not only related to the gelation capability of the PVDF copolymer nanofibers, but also attributed to the increased porosity and capillary effect on nanofibrous structure of the electrospun nanofiber coatings. Enhancement of the separator–electrode adhesion was owing to the adhesion properties of the copolymer nanofiber coatings. Compared with the PVDF-co-CTFE/PVDF-co-HFP blend nanofiber coatings studied, the PVDF-co-CTFE coating was more effective in improving the electrolyte uptake and separator–electrode adhesion. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

The absorption spectrum of polycrystalline silver halide fibres

The wavelength dependence of the attenuation in polycrystalline AgCl:AgBr fibre has been determined between 2.5 μm and 14 μm. The background attenuation as λ^-2 dependence as expected but there are also strong absorption peaks due to water and silver oxide which, to our knowledge, are observed for the first time in these fibres.     

Preparation of 1,8-naphthalimides as candidate fluorescent probes of hypoxic cells

A number of nitro- and dinitro-1,8-naphthalimides have been prepared as potential fluorescent probes of hypoxic cells. The susceptibility of 4-nitro-1,8-naphthalic anhydrides and -naphthalimides to nucleophilic displacement of the nitro group has been demonstrated by reaction with 1-butanethiol to yield 4-butylthio derivatives. Attempted nitration of these 4-butylthio derivatives with sodium nitrate and concentrated sulphuric acid yielded the corresponding sulphoxides in high yield.     

Production ofρ +, −, 0 (770),η(550), ω(783) andf 2(1270) mesons in\bar v neon and ν neon charged current interactions

The production of the meson resonances ?(770) (all three charge states), η(550), ω(783) andf ₂(1270) in \(\bar v\) Ne and ν Ne charged current interactions is investigated in a bubble chamber experiment with BEBC at CERN. Except for thef ₂, the main features of resonance production are reasonably well described by the Lund model, although the average resonance multiplicities are overestimated by the model by (67±30)%. The average multiplicities of all resonances, including thef ₂, are well reproduced by a semiempirical model, whose parameters were determined from hadron interaction data.     

The transformation of α-aminoacids into fluoroacids

The reactions of some α-aminoacids with excess sodium nitrite in polyhydrogen fluoride-pyridine are described.