Polarization in inclusive reactions

A formalism for discussing the spin dependence of inclusive reactions is presented. The role of various constraints following from conservation of parity and angular momentum conservation is discussed. Expressions for specific single and double polarization observables are presented. Predictions of the triple-Regge model for these observables are given.     

Amplitude analyses of the reactions π+p → (ϱ0, ω) Δ++ at 7.1 GeV/c

New data are presented, in the form of statistical tensors, for the reactions π⁺p → (?⁰, ω)Δ⁺⁺ at 7.1 GeV/c. Using these data, two types of model-dependent amplitude analyses have been performed. Both analyses, though based on different sets of assumptions, yield results which are in agreement with each other. The structure observed in the magnitudes and phases of the extracted amplitudes is consistent with that expected on the basis of currently accepted phenomenological ideas.     

On the determination of bond angles of triatomic radicals from electron spin resonance

The s and the p density of the sp hybrid orbital of the unpaired electron on the central nucleus of CO^?₂ and BF₂ are calculated as a function of the bond angle by the INDO molecular orbital method. The theory yields a dependence of the ratio of the p density to the s density on bond angle markedly different from a dependence derived from the orthogonality of sp hybrid orbitals and commonly used to determine the bond angle from ESR data.     

A study of inclusive vector meson production

Data are presented on the reactions π⁺n → ?⁰+X and $\text{K}{}^{\mathrm{?}}\text{p}\text{→}\text{K}{}^1\text{0}\text{(890)+}\text{X}\text{at 6.0}\text{and}\text{7.3}\text{GeV}\text{/c}$, respectively. Comparisons are made with related reactions at higher energies.     

Determination of therapeutic and toxic concentrations of doxepin and loxapine using gas-liquid chromatography with a nitrogen-sensitive detector, and gas chromatography-mass spectrometry of loxapine

A gas-liquid chromatographic procedure is presented for the determination of therapeutic and toxic serum levels of doxepin and loxapine, using a nitrogen-phosphorus-sensitive detector. Amitriptyline is used as the internal standard. The method is accurate, sensitive and specific with no derivatization required prior to analysis. An advantage of the procedure is the small serum sample size needed for analysis and the selectivity and sensitivity of the detector, with the limit of detection being 3 and 2 microgram/l for doxepin and loxapine, respectively. Nine cases of doxenin and loxapine misuse are presented. Serum doxepin concentrations ranged from 113 to 439 microgram/l, with a loxapine concentration of 192 microgram/l observed in one patient. The presence of the tricyclics was identified and confirmed by gas chromatography-mass spectrometry and the mass spectrum of loxapine is reported.     

The 16O(γ, po) reaction at intermediate photon energies

The ¹⁶O(γ, p_o) reaction has been investigated between photon energies E_γ = 40 and 105 MeV using a bremsstrahlung beam, full angular distributions being obtained at E_γ = 60, 80 and 100 MeV. While cross-section calculations which introduce a residual interaction of Yukawa form agree well with the data, the need for further work is indicated.     

Increasing the B/N ratio in boron nitride nanoribbons,a possible approach to dilute magnetic semiconductors

Density functional theory (DFT) employing the local spin density approximation and including correlation functionals is used to show that increasing the boron content relative to the nitrogen content in boron nitride nanoribbons can significantly reduce the band gap making the ribbons semiconducting. Armchair ribbons, but not zigzag ribbons, having excess borons are predicted to have a more stable optimized triplet structure than the optimized singlet structure. The triplet structure is predicted to have a higher density of states at the top of the valence band near Fermi level for the spin down state indicating it could be a ferromagnetic semiconductor. The results suggest a possible new approach to developing ferromagnetic semiconductors.     

Frequency Domain Fluorescence Lifetime Study of Crude Petroleum Oils

Frequency domain (FD) fluorescence lifetime data was collected for a series of 20 crude petroleum oils using a 405 nm excitation source and over a spectral range of ~426 to ~650 nm. Average fluorescence lifetimes were calculated using three different models: discrete multi-exponential, Gaussian distribution, and Lorentzian distribution. Fitting the data to extract accurate average lifetimes using the various models proved easier and less time consuming for the FD data than with Time Correlated Single Photon Counting (TCSPC) methods however the analysis of confidence intervals to the computed average lifetimes proved cumbersome for both methods. The uncertainty in the average lifetime was generally larger for the discrete lifetime multi-exponential model when compared to the distribution-based models. For the lifetime distributions, the data from the light crude oils with long lifetimes generally fit to a single decay term. Heavier oils with shorter lifetimes required multiple decay terms. The actual value for the average lifetime is more dependant on the specific fitting model employed than the data acquisition method used. Correlations between average fluorescence lifetimes and physical and chemical parameters of the crude oils were made with a view to developing a quantitative model for predicting the gross chemical composition of crude oils. It was found that there was no significant benefit gained by using FD over TCSPC other than more rapid data analysis in the FD case. For the FD data the Gaussian distribution model for fluorescence lifetime gave the best correlations with chemical composition allowing a qualitative correlation to some bulk oil parameters.