2,241 research outputs found
The Stink Bugs (Hemiptera: Heteroptera: Pentatomidae) of Washington State
Froeschner (1988) recorded 23 species of stink bugs (Hemiptera: Heteroptera: Pentatomidae) from Washington State. Based on material primarily housed in the M. T. James Entomological Collection at Washington State University, the number of species is increased to 51. Three species recorded by Froeschner (1988) were not found in our collections: Apateticus crocatus (Uhler), Chlorochroa rossiana Buxton and Thomas, and Tepa rugulosa (Say). Species recorded from Washington State for the first time are: Apoecilus bracteatus (Fitch), Perillus bioculatus (Fabricius), Podisus maculiventris (Say), P. pallens (Stål), P. placidus Uhler, P. serieventris Uhler, Zicrona caerulea (Linnaeus), Halyomorpha halys (Stål), Brochymena quadripustulata (Fabricius), B. sulcata Van Duzee, Acrosternum hilare (Say), Aelia americana Dallas, Banasa euchlora Stål, B. tumidifrons Thomas and Yonke, Chlorochroa congrua Uhler, Coenus delius (Say), Cosmopepla uhleri Montandon, Dendrocoris pini Montandon, Euschistus servus (Say), E. tristigmus (Say), E. variolarius (Palisot), Holcostethus limbolarius (Say), Neottiglossa sulcifrons Stål, N. undata (Say), Prionosoma podopioides (Uhler), Tepa yerma (Rolston), Trichopepla grossa (Van Duzee), and Amaurochrous vanduzeei Barber and Sailer
CaCu_3Ti_4O_12/CaTiO_3 Composite Dielectrics: A Ba/Pb-free Ceramics with High Dielectric Constants
We have measured dielectric properties of CaCuTiO
( = 0, 0.1, 0.5, 1, 1.5, 2, 2.9 and 3), and have found that
CaCuTiO (a composite of CaCuTiO and
CaTiO) exhibits a high dielectric constant of 1800 with a low dissipation
factor of 0.02 below 100 kHz from 220 to 300 K. These are comparable to (or
even better than) those of the Pb/Ba-based ceramics, which could be attributed
to a barrier layer of CaTiO on the surface of the CaCuTiO
grains. The composite dielectric ceramics reported here are environmentally
benign as they do not contain Ba/Pb.Comment: 4 pages, 4 figures, Appl. Phys. Lett. (scheduled on July 25, 2005
Followup Observations of SDSS and CRTS Candidate Cataclysmic Variables
We present photometry of 11 and spectroscopy of 35 potential cataclysmic
variables from the Sloan Digital Sky Survey, the Catalina Real-Time Transient
Survey and vsnet-alerts. The photometry results include quasi-periodic
oscillations during the decline of V1363 Cyg, nightly accretion changes in the
likely Polar (AM Herculis binary) SDSS J1344+20, eclipses in SDSS J2141+05 with
an orbital period of 76+/-2 min, and possible eclipses in SDSS J2158+09 at an
orbital period near 100 min. Time-resolved spectra reveal short orbital periods
near 80 min for SDSS J0206+20, 85 min for SDSS J1502+33, and near 100 min for
CSS J0015+26, RXS J0150+37, SDSS J1132+62, SDSS J2154+15 and SDSS J2158+09. The
prominent HeII line and velocity amplitude of SDSS J2154+15 are consistent with
a Polar nature for this object, while the lack of this line and a low velocity
amplitude argue against this classification for RXS J0150+37. Single spectra of
10 objects were obtained near outburst and the rest near quiescence, confirming
the dwarf novae nature of these objects.Comment: 34 pages, 14 figures, in press at A
Carrier relaxation mechanisms in self-assembled (In,Ga)As/GaAs quantum dots: Efficient P -> S Auger relaxation of electrons
We calculate the P-shell--to-S-shell decay lifetime \tau(P->S) of electrons
in lens-shaped self-assembled (In,Ga)As/GaAs dots due to Auger electron-hole
scattering within an atomistic pseudopotential-based approach. We find that
this relaxation mechanism leads to fast decay of \tau(P->S)~1-7 ps for dots of
different sizes. Our calculated Auger-type P-shell--to-S-shell decay lifetimes
\tau(P->S) compare well to data in (In,Ga)As/GaAs dots, showing that as long as
holes are present there is no need for an alternative polaron mechanism.Comment: Version published in Phys. Rev.
Edwin Y. Montanye Letter
A letter originally sent by Arthur E. Landolt, minister of Morehead Christian Church, to Edwin Y. Montanye, pastor of Holmesburg Baptist Church, regarding the baptism of William Morrison and a return note by Pastor Montanye from Philadelphia, Pennsylvania on November 30, 1942 to the First Christian Church of Morehead, Kentucky.https://scholarworks.moreheadstate.edu/mfcc_ww2_letters/1082/thumbnail.jp
The Pastor\u27s Study, 1941
Report of Pastor Arthur E. Landolt of the First Christian Church of Morehead, Kentucky from October 8, 1941.
A photometric study of the young open cluster NGC 1220
We present UBV CCD observations obtained in the field of the northern open
cluster NGC 1220, for which little information is available. We provide also BV
CCD photometry of a field 5 northward of NGC 1220 to take into
account field star contamination. We argue that NGC 1220 is a young compact
open cluster, for which we estimate a core radius in the range
arcmin. We identify 26 likely candidate members with spectral type earlier than
, down to =15.00 mag on the basis of the position in the two-colour
Diagram and in the Colour Magnitude Diagrams (CMDs). By analyzing the
distribution of these stars in the colour-colour and CMDs, we find that NGC
1220 has a reddening E mag, is placed pc
distant from the Sun, and has an age of about 60 Myrs. The cluster turns out to
be located about 120 pc above the Galactic plane, relatively high with respect
to its age.Comment: 7 pages, 8 eps figures, accepted for publication in A&
Self-consistent model for ambipolar tunneling in quantum-well systems
We present a self-consistent approach to describe ambipolar tunneling in
asymmetrical double quantum wells under steady-state excitation and extend the
results to the case of tunneling from a near-surface quantum well to surface
states. The results of the model compare very well with the behavior observed
in photoluminescence experiments in asymmetric double quantum
wells and in near-surface single quantum wells.Comment: 10 pages, REVTeX 3.
Phonons in the beta-tin, Imma, and sh phases of Silicon from ab initio calculations
We present a new interpretation of measured Raman frequencies of a
high-pressure structure of Silicon which was assigned previously to the
beta-tin phase. Our results show that the beta-tin->Imma->sh phase transitions
have been already indicated in this experiment which was performed before the
discovery of the Imma phase. We have calculated phonon-dispersion curves for
the beta-tin, Imma, and sh phases of silicon using the plane-wave
pseudopotential approach to the density-functional theory and the
density-functional perturbation theory within the local density approximation.
With the new assignment, the calculated phonon frequencies display an excellent
agreement with the experimental data, and can be also used to determine
precisely the transition pressure for the Imma->beta-tin phase transition. The
sh->Imma transition is accompanied by soft modes.Comment: 4 pages, 5 figure
The large amplitude outburst of the young star HBC 722 in NGC 7000/IC 5070, a new FU Orionis candidate
We report the discovery of a large amplitude outburst from the young star HBC
722 (LkHA 188 G4) located in the region of NGC 7000/IC 5070. On the basis of
photometric and spectroscopic observations, we argue that this outburst is of
the FU Orionis type. We gathered photometric and spectroscopic observations of
the object both in the pre-outburst state and during a phase of increase in its
brightness. The photometric BVRI data (Johnson-Cousins system) that we present
were collected from April 2009 to September 2010. To facilitate transformation
from instrumental measurements to the standard system, fifteen comparison stars
in the field of HBC 722 were calibrated in the BVRI bands. Optical spectra of
HBC 722 were obtained with the 1.3-m telescope of Skinakas Observatory (Crete,
Greece) and the 0.6-m telescope of Schiaparelli Observatory in Varese (Italy).
The pre-outburst photometric and spectroscopic observations of HBC 722 show
both low amplitude photometric variations and an emission-line spectrum typical
of T Tau stars. The observed outburst started before May 2010 and reached its
maximum brightness in September 2010, with a recorded Delta V~4.7 mag.
amplitude. Simultaneously with the increase in brightness the color indices
changed significantly and the star became appreciably bluer. The light curve of
HBC 722 during the period of rise in brightness is similar to the light curves
of the classical FUors - FU Ori and V1057 Cyg. The spectral observations during
the time of increase in brightness showed significant changes in both the
profiles and intensity of the spectral lines. Only H alpha remained in
emission, while the H beta, Na I 5890/5896, Mg I triplet 5174, and Ba II
5854/6497 lines were in strong absorption.Comment: 4 pages, 6 figures, accepted for publication in A&
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