Spectral analysis and kinetic modeling of radioluminescence in air and nitrogen.

In this article we present a quantitative analysis of the second positive system of molecular nitrogen and the first negative system of the molecular nitrogen cation excited in the presence of ionizing radiation. Optical emission spectra of atmospheric air and nitrogen surrounding 210Po sources were measured from 250 to 400 nm. Multi-Boltzmann and non-Boltzmann vibrational distribution spectral models were used to determine the vibrational temperature and vibrational distribution function of the emitting N2(C3Πu) and N2+(B2Σ+u) states. A zero-dimensional kinetic model, based on the electron energy distribution function (EEDF) and steady-state excitation and de-excitation of N2(X1Σ+g), N2+(B2Σ+u), N2+(X2Σ+g), N4+, O2+, and N2(C3Πu, v), was developed for the prediction of the relative spectral intensity of both the N2+(B2Σ+u → X2Σ+g) emission band and the vibrational bands of N2(C3Πu → B3Πg) for comparison with the experimental data.

Investigation of the exclusive 3He(e,e' pn)1H reaction.

Cross sections for the 3He(e,e' pn)1H reaction were measured for the first time at energy transfers of 220 and 270 MeV for several momentum transfers ranging from 300 to 450 MeV/c. Cross sections are presented as a function of the momentum of the recoil proton and the momentum transfer. Continuum Faddeev calculations using the Argonne V18 and Bonn-B nucleon-nucleon potentials overestimate the measured cross sections by a factor 5 at low recoil proton momentum with the discrepancy becoming smaller at higher recoil proton momentum.

Probing cold dense nuclear matter.

The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.

Investigation of proton-proton short-range correlations via the 12C(e,e'pp) reaction.

We investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2=2 (GeV/c)2, xB=1.2, and in an (e, e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For (9.5+/-2)% of the 12C(e,e'p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e'p) missing-momentum vector, an experimental signature of correlations.

Quasifree pi0 and pi- electroproduction on 4He in the Delta-resonance region.

The reactions 4He(e, e' p3He)pi- and 4He(e, e' p3He)pi0 were studied simultaneously, and for the first time, in a large kinematical domain including the Delta-resonance region. This was achieved by detecting the recoiling 3He and 3H nuclei instead of the emitted pions. The dependences of the cross section on the recoil momentum p(rec), the invariant mass WpiN, and the direction thetapi,q' and phipi,q' of the produced pion, are globally well described by the results of (quasifree) distorted-wave impulse approximation calculations. However, in the Delta-resonance region there are clear discrepancies, which point to medium modifications of the Delta in 4He.

Electron-induced neutron knockout from 4He.

The differential cross section for electron-induced neutron knockout in the reaction 4He(e,e(')n)(3)He has been measured for the first time with a statistical accuracy of 11%. The experiment was performed in quasielastic kinematics at a momentum transfer of 300 MeV/c and in the missing-momentum range of 25-70 MeV/c. The comparison of the data with theoretical calculations shows an impressive increase of the cross section resulting from final state interaction effects. Specifically, the p-n charge-exchange process dominates the cross section in this kinematical regime.

Influence of the roll compactor parameter settings and the compression pressure on the buccal bio-adhesive tablet properties.

Miconazole buccal tablets were prepared via a dry granulation process. By applying a factorial design (2(4)), the roll compactor parameters (compaction force, gap between the rolls, type of the rolls (smooth, ribbed) and the sieve aperture) were optimised for the tablet strength. The compaction force and the roll type significantly affected the tablet strength. Afterwards, a quarter fractional factorial design (2(5-2)) was applied, consisting of the four compactor parameters and additionally the compression pressure, in order to optimise these parameters for the dissolution profile and the buccal bio-adhesion characteristics (bio-adhesive force and energy). In order to evaluate the dissolution profiles properly, the similarity factor between sample and a zero-order release reference profile was used. The compression pressure and the roll type significantly affected the dissolution profile. The sieve aperture had a significant effect on the buccal adhesion properties and the compaction force had a significant effect on the dissolution profile and the bio-adhesive energy. The gap between the rolls affected the bio-adhesive force significantly.