Liquid-helium-cooled Michelson interferometer

Interferometer serves as a rocket-flight spectrometer for examination of the far infrared emission spectra of astronomical objects. The double beam interferometer is readily adapted to make spectral scans and for use as a detector of discrete line emissions

A comment on "Amplification of endpoint structure for new particle mass measurement at the LHC"

We present a comment on the kinematic variable $m_{CT2}$ recently proposed in "Amplification of endpoint structure for new particle mass measurement at the LHC". The variable is designed to be applied to models such as R-parity conserving Supersymmetry (SUSY) when there is pair production of new heavy particles each of which decays to a single massless visible and a massive invisible component. It was proposed in "Amplification of endpoint structure for new particle mass measurement at the LHC" that a measurement of the peak of the $m_{CT2}$ distribution could be used to precisely constrain the masses of the SUSY particles. We show that when Standard Model backgrounds are included in simulations, the sensitivity of the $m_{CT2}$ variable to the SUSY particle masses is more seriously impacted for $m_{CT2}$ than for other previously proposed variables.Comment: 5 page

Red Crossbill Invasion of Northwestern Arkansas during 2012-2013

An irruption of Red Crossbills (Loxia curvirostra) occurred in primarily northwestern Arkansas starting in November of 2012 and lasting to the end of May of 2013. Based on recordings of call notes, most birds around Fayetteville were Type 2, the large-billed ponderosa pine crossbill, associated with a variety of conifer species. Birds recorded in Carroll County were Type 3, the small-billed western hemlock crossbill, and they were associated with small cones on shortleaf pine (Pinus echinata). One recording was obtained in Fayetteville of Type 5, the lodgepole pine crossbill, only the third recording east of the Great Plains. Crossbills at the Fayetteville Country Club were observed eating algae (Cladophora sp.) during the months of December and January, a behavior rarely reported for passerines. During March, crossbills appeared at sunflower bird feeders, which is a relatively recent phenomenon associated with low conifer seed abundance. The first two Arkansas specimens of crossbills (probably Type 3) were obtained from birds that struck windows near feeders. This is only the third recorded irruption of crossbills in Arkansas in the last 43 years, suggesting that crossbills rarely travel this far south in search of cone crops

Comparison of boiler feed pumps for cesium and potassium Rankine cycle systems

Comparison of electromagnetic and centrifugal pumps for cesium and potassium Rankine cycle system

Generating entanglement with low Q-factor microcavities

We propose a method of generating entanglement using single photons and electron spins in the regime of resonance scattering. The technique involves matching the spontaneous emission rate of the spin dipole transition in bulk dielectric to the modified rate of spontaneous emission of the dipole coupled to the fundamental mode of an optical microcavity. We call this regime resonance scattering where interference between the input photons and those scattered by the resonantly coupled dipole transition result in a reflectivity of zero. The contrast between this and the unit reflectivity when the cavity is empty allow us to perform a non demolition measurement of the spin and to non deterministically generate entanglement between photons and spins. The chief advantage of working in the regime of resonance scattering is that the required cavity quality factors are orders of magnitude lower than is required for strong coupling, or Purcell enhancement. This makes engineering a suitable cavity much easier particularly in materials such as diamond where etching high quality factor cavities remains a significant challenge

Study of the de Almeida-Thouless line using power-law diluted one-dimensional Ising spin glasses

We test for the existence of a spin-glass phase transition, the de Almeida-Thouless line, in an externally-applied (random) magnetic field by performing Monte Carlo simulations on a power-law diluted one-dimensional Ising spin glass for very large system sizes. We find that an Almeida-Thouless line only occurs in the mean field regime, which corresponds, for a short-range spin glass, to dimension d larger than 6.Comment: 4 pages, 2 figures, 1 tabl

Hydrological Investigations at Biafo Glacier, Karakoram Range, Himalaya; an Important Source of Water For the Indus River

Over 80% of the flow of the Upper Indus River is derived from less than 20% of its area: essentially from zones of heavy snowfall and glacierized basins above 3500 m elevation. The trans-Himalaya n contribution comes largely from an area of some 20000 km2 of glacierized basins, mostly along the axis of the Greater Karakoram range and especially from 20-30 of the largest glacier basins. Very few glaciological investigations have so far been undertaken in this the major glacierized region of Central Asia. Biafo Glacier, one of the largest of the Karakoram glaciers, drains south-eastwards from the central Karakoram crest. Its basin covers a total area of 853 km2 , 628 km2 of which are permanent snow and ice, with 68% of the glacier area forming the accumulation zone. This paper describes investigations of snow accumulation, ablation , glacier movement, and glacier depth undertaken in the period 1985-87 , set against a background of investigations carried out over the last 130 yea rs. Biafo Glacier differs from most of the other Karakoram glaciers in being nourished mainly by direct snowfall rather than by avalanching; this has the advantage of allowing extensive investigation of accumulation over a broad range of altitude. Snow-accumulation studies in the Biafo Glacier basin have indicated that annual accumulation varies from 0.9 to 1.9 m of water equivalent between 4650 and 5450 m a .. s.l. This suggests an annual moisture input above the equilibrium line of approximately 0.6 km3. Monopulse radar measurements indicate the presence of ice thickness as great as 1400 m at the equilibrium line, although these results may not be completely reliable . Mean surface velocity during the summer of 0.8 m d -I has been measured near to the equilibrium line. Calculations of annual ice flux through the vertical cross-profile at the equilibrium line indicate a throughput of 0.7 km3 a-I Estimates from stake ablation measurements also suggest that ice loss on Biafo Glacier is about 0.7 km3 a-I. The close agreement between these three sets of measurements is reassuring, indicating that the ablation zone of Biafo Glacier, whose area covers 0.09% of the whole Upper Indus basin, produces approximately 0.9% of the total run-off. However. it should be mentioned that this estimate does not include water originating from seasonal snow melt, e either above or below the equilibrium line, or from rainfall. Net annual ice losses due to wastage of the glacier since 1910 are probably of the order of 0.4-{).5 m a-I; this would represent between 12 and 15% of annual water yield from melting ice

Structural and elastic characterization of Cu-implanted SiO₂ films on Si(100) substrates

Cu-implanted SiO₂ films on Si(100) have been studied and compared to unimplanted SiO₂ on Si(100) using x-ray methods, transmission electron microscopy, Rutherford backscattering, and Brillouin spectroscopy. The x-ray results indicate the preferred orientation of Cu {111} planes parallel to the Si substrate surface without any directional orientation for Cu-implanted SiO₂∕Si(100) and for Cu-implanted and annealedSiO₂∕Si(100). In the latter case, transmission electron microscopy reveals the presence of spherical nanocrystallites with an average size of ∼2.5 nm. Rutherford backscattering shows that these crystallites (and the Cu in the as-implanted film) are largely confined to depths of 0.4−1.2 μm below the film surface. Brillouin spectra contain peaks due to surface, film-guided and bulk acoustic modes. Surface (longitudinal) acoustic wave velocities for the implanted films were ∼7% lower (∼2% higher) than for unimplanted SiO₂∕Si(100). Elastic constants were estimated from the acoustic wave velocities and film densities. C₁₁ (C₄₄) for the implanted films was ∼10% higher (lower) than that for the unimplanted film. The differences in acoustic velocities and elastic moduli are ascribed to implantation-induced compaction and/or the presence of Cu in the SiO₂ film.B.J. and M.C.R. are grateful for financial support from the Australian Synchrotron Research Program, funded by the Commonwealth of Australia. M.C.R. would also like to thank the Australian Research Council for their financial support. The financial support of the Natural Sciences and Engineering Research Council of Canada NSERC is gratefully acknowledged by G.T.A. and J.S

Survey of information on turbine bucket erosion

Turbine bucket erosion in steam, mercury, and potassium vapor turbines for use in space power plant