Within the Herschel key project “The Warm And Dense ISM” (WADI) we systematically observe a number of prominent photon-dominated regions (PDRs) to measure the impact of varying UV fields on the energy balance, the chemical and dynamical structure of heated molecular clouds.

Field enclosure and laboratory cage experiments designed to measure the impact of the parasitoid Microctonus hyperodae Loan on the Argentine stem weevil, Listronotus bonariensis (Kuschel) have shown that under high parasitoid pressure, there is significant weevil mortality without obvious parasitism. Parasitoid-exposed, but unparasitized portions of caged populations died at rates significantly higher than both the parasitized weevils from the same population and the unexposed controls. Unexpectedly, parasitized weevils had the lowest mortality rates (prior to larval parasitoid emergence). It was of ecological significance that this mortality effect was detected under field conditions using several years of empirically-collected population dynamics data. Under both field and laboratory conditions this mortality was found to occur within shorter time intervals than that required for full parasitoid larval development; thus it could not be attributed to the mortality that occurs after the emergence of prepupal parasitoids. The mechanism for this mortality remains undetermined, although it could possibly be linked to pseudoparasitism.

The Analytical Instrumentation Facility (AIF) is a laboratory composed of scientists and engineers specializing in the development and application of advanced techniques for materials characterization (http://spm.aif.ncsu.edu/aif/index.html)http://www.nice.org.uk/page.aspx?o=43210. AIF facilities include an extensive collection of analytical instrumentation utilized in teaching, research, and in support of academic and industrial programs. General forms of analysis include: electron, ion, and photon microscopies, surface science and analysis, and scanned probe microscopies. An abbreviated listing of AIF capabilities follows: metallography/sample preparation, optical microscopy, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Secondary Ion Mass Spectroscopy (SIMS), Secondary Electron Microscopy (SEM), Scanned Probe Microscopy (SPM), Micro-Raman Spectroscopy, Focused Ion Beam Micro-machining (FIBM), Auger Electron Spectroscopy (AES), and X-Ray Photoelectron Spectroscopy (XPS or ESCA).

AIF is a resource utilized not only by those within NC State requiring analytical services, but also by a large number of North Carolina non-profit and industrial organizations as well as the Materials Community at large.

Nanoindentation is becoming an increasingly important tool for the characterization of the mechanical properties of materials on the nanometer scale. The mechanical response of a material is measured by recording the force acting between an indenter and the material while displacing the indenter into the material. The shape of the recorded load displacement curves is not only dependent on the mechanical properties of the material, but also strongly dependent on indenter geometry. To minimize difficulties in the extraction of quantitative material mechanical property information from the force curve, indenter geometry must be controlled and characterized on the same scale as the indentation, i.e. on the nanometer scale. Diamond, the hardest naturally occurring material, is an obvious choice as the indenter material. Conventional lapping techniques4 do not provide sufficient control to produce indenter geometries of the shapes and to the precision required for optimal nanoindentation measurements.

We have observed IRAS 09371+1212 using both narrow and broad band filters. As a result, we note that relative color trends B-V/V-R appear to be inconsistent with both the mean IS reddening law, and the variation deduced for model grains (Robinson et al, 1992). There also appears to be a disparity in the B-V/V-R reddening gradient as between the inner and outer source envelopes—a characteristic which, together with other evidence, may indicate a corresponding evolution in grain properties.

Fabrication of Si1-xGex and Si-1-x-yGexCy layers on Si(100) by high-dose ion implantation of 72Ge ions without and with 12C ions and subsequent high-energy and low-energy ion-beam-induced epitaxial crystallization (IBIEC) has been investigated. Structural properties of the surface layers were observed by RBS-channeling technique. Si(100) wafers were implanted with 150keV and 80keV Ge ions at room temperature so as to produce a peak concentration of Ge amounting to approximately 2 and 14 at.%, respectively. C ions were additionally implanted to a fluence of 10% of Ge concentration for the SiGeC samples. IBΓEC experiments performed with 400keV 18Ar ion bombardments have induced crystallization of the amorphous layers of SiGe and SiGeC on Si up to the surface at 400°C for both samples with low Ge concentration (2%) and high Ge concentration (14%). IBIEC using 72Ge ions with energies whose projected ranges are within the amorphous layer was alternatively performed for SiGe layer on Si. Bombardments of 140keV and 40keV Ge ions at 400°C have induced crystallization up to the surface with a slight disorder in the grown layer. Present experimental results suggest a novel ion beam synthesis method of fabrication of SiGe (SiGeC) on Si at low temperatures.

The preparation of amorphous insulating films containing nanometer-scaled structures of semiconductors has attracted increased attention since the observation of room temperature emission of light from films containing indirect-bandgap semiconductors such as Ge and Si. While most experimental reports on these Si and Ge nano-scale structures have been based on thin films created using sputter-deposition, in this study we have used conventional ion implantation of Ge to create the non-equilibrium mixture of materials that, upon annealing, develops a nano-crystallite phase embedded in the amorphous matrix. The presence of clusters that are difficult to image in TEM, in addition to microcrystallites, is an issue of interest since the source of light emission is still controversial. The second phase is formed from excess amounts of the semiconductor, in this case added by implantation. In this paper the formation and size distribution of the Ge nano-structures was characterized using Raman scattering and transmission electron microscopy (TEM). Similarly to reported sputtered film results, Raman spectra suggest Ge clusters that are not well formed crystallites may be present for anneals at low temperatures and in unannealed films. For annealing temperatures exceeding 600°C, a mixture of amorphous-like clustering and nano-crystallites may result, depending on the volume fraction of Ge. For low dose samples it was found that temperature and time of annealing could be used to manipulate the nucleation behavior of the nano-crystallites.

We present new calculations for ls−2p transitions in C−, N−, and O-like Ti, Cr, and Ni for application to tokamak X-ray spectra. This extends our earlier work for the corresponding iron ions (Phillips et al. 1983, Ap.J. 265, 1120) in which a density dependence of line intensities was pointed out. These lines are principally formed by dielectronic recombination; the density effect arises due to the density-dependent populations of the fine structure levels in the ground configuration of the recombining ion. In the present work the calculations of the Ti, Cr, and Ni lines have been made for the wavelengths and the dielectronic recombination rates using a Hartree-Fock technique with statistical exchange. The density dependence of the collisionally excited transitions was also included. Density-dependent populations of the fine structure levels of the ground configuration were obtained from Feldman et al. (1980 J. Appl. Phys. 51, 190) and Bhatia et al. (1980, J. Appl. Phys. 51, 1464). In calculating the ionization fractions we have assumed coronal equilibrium; new ionization rate coefficients were calculated using the formalism given by Burgess and Chidichimo (1983). The spectra were synthesized with Voigt line profiles and typical tokamak radius-dependent temperature and density profiles were assumed. The N-like lines, in-particular show a strong dependence over tha range: <1011 −3.1013 cm−3 (Ti XVI) <1011 −3.1014 cm−3 (Cr XVIII), 1012 −1015 cm−3 (Ni XXII). If a density profile across the torus is available from Thomson-scattered laser radiation, observations of these lines may serve to show where the N-like ions are formed in the tokamak plasma.

The X-Ray Polychromator (XRP) resumed operations on 24 April 1984 following the successful in-orbit repair of the Solar Maximum Mission Satellite. Since that time the two instruments that comprise the XRP, the Flat Crystal Spectrometer (FCS) and the Bent Crystal Spectrometer (BCS), have been used to obtain new spectroscopic data from active regions and flares. The FCS, in particular, has accumulated far more observations of soft X-ray line profiles than were obtained during SMM-I in 1980. For this short presentation, we have chosen two topics to illustrate the type of data that we have obtained since the repair.