Current and Charge Distributions along an Antenna in a Cylinder of Cold Plasma

The analysis of the insulated antenna in a relatively dense medium is modified to apply to a thin cylindrical dipole antenna (radius a, length 2h) in a glass tube filled with a homogeneous cold plasma. Account is taken of the finite radius b of the plasma column and of the thickness (c - b) of the containing tube. Complex wave numbers, distributions of current and charge, and driving-point admittances have been calculated for dipoles with electrical lengths up to two wavelengths with 3 ? b/a ? 28, 0.75 ? (?p/?)2 ? 1.05, and 0.01 ? ?/?p ? 0.10. The effect of the thickness and permittivity of the glass tube on the wave number and admittance is determined. Numerous graphs and tables are provided.     

Eliminating Indeterminacy in Singularly Perturbed Boundary Value Problems with Translation Invariant Potentials

Solutions exhibiting an internal layer structure are constructed for a class of nonlinear singularly perturbed boundary value problems with translation invariant potentials. For these problems, a routine application of the method of matched asymptotic expansions fails to determine the locations of the internal layer positions. To overcome this difficulty, we present an analytical method that is motivated by the work of Kath, Knessl and Matkowsky [4]. To construct a solution having n internal layers, we first linearize the boundary value problem about the composite expansion provided by the method of matched asymptotic expansions. The eigenvalue problem associated with the homogeneous form of this linearization is shown to have n exponentially small eigenvalues. The condition that the solution to the linearized problem has no component in the subspace spanned by the eigenfunctions corresponding to these exponentially small eigenvalues determines the internal layer positions. These “near” solvability conditions yield algebraic equations for the internal layer positions, which are analyzed for various classes of nonlinearities.     

The Abramov-Rokhlin entropy addition formula for amenable group actions

In this note we show that the entropy of a skew product action of a countable amenable group satisfies the classical formula of Abramov and Rokhlin.     

Ansätze for self-dual Yang-Mills fields

A sequenceA ₁,A ₂, ... of ansätze for generating self-dual solutions of the Yang-Mills equations is presented. For eachn,A _n produces a solution depending on two arbitrary functions of three variables. As an application, we see thatA ₂ generates a static Yang-Mills-Higgs 2-monopole solution.     

g-Factor for the K=6, Jπ=6+ isomer in178Hf

Hyperfine Interactions -     

Rotating frame spin—lattice relaxation in solid hydrated methaemoglobin

Proton T_1? relaxation times in two samples of methaemoglobin with different water contents showed that a process occurs with a correlation time of the order 10^?s s at 240 K. This is probably an exchange of molecules between bound and free water.     

A 57Fe Mössbauer study of four pyrite compounds: CoS2, NiS2, CoSe2 and NiSe2

Mössbauer spectra of ⁵⁷Fe-doped CoS₂, NiS₂, CoSe₂ and NiSe₂ have been taken at various temperatures between 300 and 16 K, and the hyperfine parameters H and θ measured for those substances showing magnetic hyperfine splitting. Quadrupole splitting $\text{QS}\text{(=}\text{1}\text{2}\text{e}{}^2\text{qQ)}$ was also measured and for NiS₂ and CoS₂ the sign of QS was determined.The room temperature value of QS showed a similar behaviour in the series FeS₂CoS₂NiS₂ to that in the series FeSe₂CoSe₂NiSe₂. The absolute value of QS decreased slightly below the magnetic transition temperature in those compounds which showed magnetic ordering.     

M-ideal structure in Banach algebras

It is shown that M-ideals in a Banach algebra with identity are subalgebras, and that they are ideals if the algebra is commutative. Counterexamples demonstrate that these are the strongest results available. The theory is then applied to familiar classes of Banach spaces.     

Diffraction and resonance production in exclusive pp interactions at 100 GeV/c

We have investigated the reactions $\text{p}\text{p}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{a}\text{?}\text{and}\text{p}\text{p}\text{a}\text{?}\text{p}\text{p}\text{2π}{}^{\mathrm{+}}\text{2π}{}^{\mathrm{?}}\text{at}\text{100}\text{GeV}\text{/c}$. The $\text{p}\text{p}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}$ final state is dominated by diffractive production of a $\text{p}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{(}\text{or}\text{p}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{)}$ system which shows a strong tendency to form $\text{Δ}{}^{\mathrm{++}}\text{π}{}^{\mathrm{?}}\text{(}\text{or}\text{Δ}{}^{\mathrm{++}}\text{π}{}^{\mathrm{+}}\text{)}$. The process $\text{p}\text{p}\text{a}\text{?}\text{Δ}{}^{\mathrm{++}}\text{Δ}{}^{\mathrm{++}}$ is also observed in this reaction, indicating an energy dependence of s^?1.5±0.1. The $\text{p}\text{p}\text{2π}{}^{\mathrm{+}}\text{2π}{}^{\mathrm{?}}$ channel shows less single diffraction, and has a doubly diffractive component consistent with pomeron factorization. Strong Δ⁺⁺(Δ⁺⁺) production is agoain seen, but in contrast to the $\text{p}\text{p}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}$ channel we also observe considerable ?⁰ production.