Survival and Growth of Two \u3ci\u3eHydraecia\u3c/i\u3e Species (Noctuidae: Lepidoptera) on Eight Midwest Grass Species

Grasses play a critical role in the life cycles of both the hop vine borer (Hydraecia immanis) and potato stem borer (H. micacea), two potentially se­rious agriculture pests. Neonate larvae of both species (Noctuidae: Lepidoptera) were reared on eight selected grasses and corn for 14-18 days under greenhouse conditions to determine their survival and growth. These were quackgrass (Agropyron repens), smooth bromegrass (Bromus inermis), orchardgrass (Dactylis glomerata), large crabgrass (Digitaria sanguinalis), barnyardgrass (Echinochloa crusgalli), giant foxtail (Seteria faberii), wild prosso millet (Panicum millaceum), Johnsongrass (Sorghum halepense), and corn (Zea mays). In a separate, concurrent experiment, H. immanis and H. micacea larvae were reared on quackgrass, smooth bromegrass and orchardgrass (narrow-stemmed grasses) and sampled after 7, 10 and 14 days. H. immanis larvae generally grew more slowly and dispersed less quickly than H. micacea larvae. The fewest H. immanis and H. micacea larvae were recovered from giant foxtail. H. immanis larvae reared on quackgrass, smooth bromegrass and orchardgrass (thin-stemmed grasses) outgrew their hosts by the third instar and rapidly dispersed, particularly from quackgrass. Due to the unique internal stem-feeding behavior of these larvae the stem thickness becomes a constraining factor regarding duration of suitability to serve as a larval host. Grass feeding has tremendous significance regarding the geographic spread, local population densities, phenological damage periods, and cultural control methods such as crop rotation for these two noctuid species

Small‐Molecule Photovoltaics Based on Functionalized Squaraine Donor Blends

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91166/1/1956_ftp.pd

Accumulation of electric-field-stabilized geminate polaron pairs in an organic semiconductor to attain high excitation density under low intensity pumping

The recombination dynamics of geminate polaron pair (PP) states are investigated by monitoring electric-field-induced delayed fluorescence in thin films consisting of the green laser dye, Coumarin-6 (C6) doped at 1 wt %1wt% into 4,4′4,4′-bis(NN-carbazolyl)biphenyl. We find that the PP decay follows τ−mτ−m (with m ∼ 0.1m∼0.1), where ττ is the time that the PPs are held in the field. This sublinear decay suggests the possibility for accumulation of PPs over time that can then be reconverted into excitons upon field removal. We demonstrate the generation of short ( ∼ 50 ns∼50ns full width at half maximum) bursts of C6 fluorescence with peak intensities >20>20 times the steady-state fluorescence intensity (corresponding to a C6 singlet exciton density NS>4×1015 cm3NS>4×1015cm3) when pumped continuously by a low intensity (<1 W/cm2(<1W∕cm2) laser in the presence of a pulsed electric field.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87790/2/193502_1.pd

Microscopic approach to pion-nucleus dynamics

Elastic scattering of pions from finite nuclei is investigated utilizing a contemporary, momentum--space first--order optical potential combined with microscopic estimates of second--order corrections. The calculation of the first--order potential includes:\ \ (1)~full Fermi--averaging integration including both the delta propagation and the intrinsic nonlocalities in the $\pi$-$N$ amplitude, (2)~fully covariant kinematics, (3)~use of invariant amplitudes which do not contain kinematic singularities, and (4)~a finite--range off--shell pion--nucleon model which contains the nucleon pole term. The effect of the delta--nucleus interaction is included via the mean spectral--energy approximation. It is demonstrated that this produces a convergent perturbation theory in which the Pauli corrections (here treated as a second--order term) cancel remarkably against the pion true absorption terms. Parameter--free results, including the delta--nucleus shell--model potential, Pauli corrections, pion true absorption, and short--range correlations are presented. (2 figures available from authors)Comment: 13 page

Active‐matrix organic light‐emitting displays employing two thin‐film‐transistor a‐Si:H pixels on flexible stainless‐steel foil

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92136/1/1.2759547.pd

General Survey of Polarization Observables in Deuteron Electrodisintegration

Polarization observables in inclusive and exclusive electrodisintegration of the deuteron using a polarized beam and an oriented target are systematically surveyed using the standard nonrelativistic framework of nuclear theory but with leading order relativistic contributions included. The structure functions and the asymmetries corresponding to the various nucleon polarization components are studied in a variety of kinematic regions with respect to their sensitivity to realistic $NN$-potential models, to subnuclear degrees of freedom in terms of meson exchange currents, isobar configurations and to relativistic effects in different kinematical regions, serving as a benchmark for a test of present standard nuclear theory with effective degrees of freedom.Comment: 56 pages, 32 figures, revtex

47.4: Blue Phosphorescent Organic Light Emitting Device Stability Analysis

A model based on defect generation by exciton‐polaron annihilation interactions between the emitter and host molecules, in a blue phosphorescent OLED, is shown to fit well with experimental data. A blue PHOLED with (0.15, 0.25) chromaticity is shown to have a half‐life, from 1,000 nits, of 690 hrs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92134/1/1.3069766.pd

Broadband Plasmonic Photocurrent Enhancement in Planar Organic Photovoltaics Embedded in a Metallic Nanocavity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108314/1/aenm201301937.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108314/2/aenm201301937-sup-0001-S1.pd