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To evaluate the monophyly of Coelogyne (Epidendroideae; Orchidaceae) and reveal sectional relationships and relations to allied genera in subtribe Coelogyninae, we collected PCR (polymerase chain reaction) amplified restriction fragment length polymorphisms (RFLPs) from 11 plastid regions for 42 taxa (28 Coelogyne species and 14 representatives of other genera) and three outgroups from Bletiinae and Thuniinae. We also sequenced a large portion of the plastid trnK intron (mostly matK) and the nuclear ribosomal DNA internal transcribed spacers ITS1 and ITS2 (including the 5.8S gene). Separate phylogenetic analyses on each data set using maximum parsimony produced mainly congruent (except for the position of Panisea) but weakly supported clades. Parsimony analysis of the combined data clearly identified three main clades in Coelogyninae. Whereas Coelogyninae are monophyletic, Coelogyne is polyphyletic, with species falling into at least two well-supported clades. The utility of morphological characters used in previous classifications was explored by reconstructing character state evolution on one of the four molecular trees. Lip base and petal shape were homoplasious, whereas ovary indumentum and flower number were congruent with well-supported groups. The implications of our results for the classification of Coelogyne are discussed, and a reorganization of the genus by including Neogyna and Pholidota and removing several species is proposed.

Using a fast pulse counting system with a time resolution of 0.7 ns, the intensity has been measured of the light originating from a negative corona discharge in the Trichel regime in air, resolved in time, in position in the gap and in wavelength. The dominant spectral lines originate from the second positive system of N2. Both the current and the emission from the plasma carrying the current show a fast increase on a nanosecond timescale and a successive slower decrease. Repetition frequencies are in the MHz range. The maximum of the light pulse intensity corresponds with the maximum of the Trichel pulse. The continuum emission measured originates from the attachment processes during the maximum in the current pulse. The electron density estimated from the continuum measurements is 1018 m-3 at maximum for air at a pressure of 100 kPa. From observed Cul line emission the sputter rate for positive ions impinging on the cathode tip has been determined to be 4*10-5 atoms ion-1.

The occurrence of negative-ion species in a negative corona discharge in the Trichel regime in N2/O2 mixtures has been studied at pressures up to 1 bar. The problems of ion sampling from discharges containing chemically active species with respect to reproducibility and mass discrimination have been adequately solved. Ion sampling took place by probing the undisturbed supersonic expansion downstream from the extraction hole with a skimmer penetrating the surrounding shock wave. No electric fields were applied between the extraction hole and the skimmer. The experiments were carried out in gas containing less than 5 volume parts per million (VPM) water and showed that the negative ions formed in the discharge chamber will cluster with water molecules. The complicated negative-ion mass spectra occurring could only be identified assuming that in the discharge chamber clustering with H2O occurs with clustering numbers up to three and that clustering in the supersonic expansion with air molecules (mainly N2) occurs with clustering numbers up to seven.

Using the Poynting vector formalism under certain assumptions an analytical expression can be derived for the electrode lead currents induced by plasma moving in an inhomogeneous electric field between a number of electrodes. Its limitations are made explicit and its validity is experimentally checked in a needle-to-plane set-up where laser induced breakdown has been studied.