36,501 research outputs found
Habitats and Spider Prey of \u3ci\u3eDipogon Sayi Sayi\u3c/i\u3e (Hymenoptera: Pompilidae) in Washington County, Maine
Spider wasps were reared from three types of trap-nests deployed in strip-clearcut areas of a spruce-fir-mixed hardwood forest of Maine. Collections of Dipogon sayi sayi from Mooseborn National Wildlife Refuge, Washington County, represent the easternmost records for the United States. Spider prey included females of Misumena vatia, Xysticus emertoni (new prey record), and X. punctatus, and juveniles and penultimate males of Xysticus sp. We found no evidence of nest-site competition between spider wasps and eumenid wasps (Hymenoptera: Eumenidae) that prey on spruce budwornl, Choristoneura fumiferana, when available nesting sites ranged from 320 to 4400
Light weight fire resistant graphite composites
Composite structures with a honeycomb core and characterized by lightweight and excellent fire resistance are provided. These sandwich structures employ facesheets made up of bismaleimide-vinyl styrylpyridine copolymers with fiber reinforcement such as carbon fiber reinforcement. In preferred embodiments the facesheets are over layered with a decorative film. The properties of these composites make them attractive materials of construction aircraft and spacecraft
Surface acoustic wave stabilized oscillators
Four areas of surface acoustic wave (SAW) controlled oscillators were investigated and a number of 401.2 MHz oscillators were constructed that showed improved performance. Aging studies on SAW devices packaged in HC36/U cold weld enclosures produced frequency drifts as low as 0.4 ppm in 35 weeks and drift rates well under 0.5 ppm/year. Temperature compensation circuits have substantially improved oscillator temperature stability, with a deviation of + or - 4 ppm observed over the range -45 C to + 40 C. High efficiency amplifiers were constructed for SAW oscillators and a dc to RF efficiency of 44 percent was obtained for an RF output of 25 mW. Shock and vibration tests were made on four oscillators and all survived 500 G shock pulses unchanged. Only when white noise vibration (20 Hz to 2000 Hz) levels of 20 G's rms were applied did some of the devices fail
Gap Symmetry of Superconductivity in UPd2Al3
The angle dependent thermal conductivity of the heavy-fermion superconductor
UPdAl in the vortex state was recently measured by Watanabe et al. Here
we analyze this data from two perspectives: universal heat conduction and the
angle-dependence. We conclude that the superconducting gap function
in UPdAl has horizontal nodes and is given by
, with .Comment: 8 pages, 4 figures, improved figures in replacemen
Direct versus Delayed pathways in Strong-Field Non-Sequential Double Ionization
We report full-dimensionality quantum and classical calculations for double
ionization of laser-driven helium at 390 nm. Good qualitative agreement is
observed. We show that the classical double ionization trajectories can be
divided into two distinct pathways: direct and delayed. The direct pathway,
with an almost simultaneous ejection of both electrons, emerges from small
laser intensities. With increasing intensity its relative importance, compared
to the delayed ionization pathway, increases until it becomes the predominant
pathway for total electron escape energy below around 5.25 . However the
delayed pathway is the predominant one for double ionization above a certain
cut-off energy at all laser intensities
Exit plane H2O concentration measurements correlated with OH PLIF near-injector mixing measurements for scramjet flows
Mixing and combusting high enthalpy flows, similar to those encountered in scramjet engines, were investigated using a shock tunnel to produce the flow in conjunction with non-intrusive optical diagnostics which monitored the performance of two injector configurations. The shock tunnel is configured to produce Mach 3 flow and stagnation enthalpies corresponding to flight equivalent Mach numbers between 7 and 11. A pulsed hydrogen injection capability and interchangeable injector blocks provide a means of examining high speed, high enthalpy reacting flows. Planar laser induced fluorescence (PLIF) of OH molecules in the near injector region produced images which show the combusting and mixing zones for the reacting flow. Line-of-sight exit plane measurement of water concentration and temperature were used to provide a unique method of monitoring exit plane products. These results demonstrated that a velocity matched axial injection system produced a fuel jet that lifted off the floor of the duct. Mixing was observed to increase for this system as a velocity mismatch was introduced. Comparison of exit plane water concentrations for a wall jet injection system and a velocity matched injection system indicated similar mixing performance but an accurate pressure measurement is necessary to further validate the result. In addition, exit plane measurements indicated an approximate steady-state condition was achieved during the 1 to 2 ms test times
Direct-Capture Model for the He3(α, γ)Be7 and T(α, γ)Li7 Reactions
Using the He3+He4 scattering phase shifts, the cross section for the He3(α, γ)Be7 reaction is calculated on the basis of a He3+He4 model for the ground state and first excited state of Be7. Capture of particles from the S, P, D, and F partial waves by means of E1, M1, and E2 transitions is considered. The results are in excellent agreement with the experimental data presented in the preceding paper and indicate that the reaction proceeds chiefly by means of E1 capture from the S and D waves. It is a surprising consequence that the D wave contributes an appreciable fraction of the total capture cross section for alpha-particle energies as low as 1 MeV. Using the same values for the reduced widths of the final states that were determined for the He3(α, γ)Be7 reaction, similar calculations have also yielded excellent agreement with the experimental data for both the branching ratio and the total cross section of the mirror reaction T(α, γ)Li7
The global addiction academy project: a global phenomenon - requiring a global solution - from a global community
The emergence of different and effective modes of e-communications has rapidly expanded possibilities for more extensive dialogue, collaboration and learning. For professionals and those working with addiction issues and support services, these offer increased opportunities to break down significant barriers to integrating issues of addiction into the care sector workforce and to ensure that the workforce can respond more appropriately and confidently and to access a range of up-to-date resources as well as to share best practice and expertise. Our international collaboration to develop a Global Classroom which started at the beginning of 2014 seeks to provide an innovative online platform for stimulating learning among people of different disciplines and interests on addictions. We aim to bring people together from diverse cultural communities to engage in dialogue, debate and to share ideas on addiction beyond their own peers, regions or country and to meet a range of learning needs within this structure which is inclusive and developmental. This symposium will share the outcomes of our early developments in the first year of developing a global addiction academy project, the challenges and possibilities particularly focusing on the impact of such methodology on achieving wider engagement on a global public health issue and enhancing inter-professional learning
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