Detecting Life-bearing Extra-solar Planets with Space Telescopes

One of the promising methods to search for life on extra-solar planets (exoplanets) is to detect life's signatures in their atmospheres. Spectra of exoplanet atmospheres at the modest resolution needed to search for oxygen, carbon dioxide, water, and methane will demand large collecting areas and large diameters to capture and isolate the light from planets in the habitable zones around the stars. For telescopes using coronagraphs to isolate the light from the planet, each doubling of telescope diameter will increase the available sample of stars by an order of magnitude, indicating a high scientific return if the technical difficulties of constructing very large space telescopes can be overcome. For telescopes detecting atmospheric signatures of transiting planets, the sample size increases only linearly with diameter, and the available samples are probably too small to guarantee detection of life-bearing planets. Using samples of nearby stars suitable for exoplanet searches, this paper shows that the demands of searching for life with either technique will require large telescopes, with diameters of order 10m or larger in space.Comment: 15 pages, 6 figures, submitted to Ap.

Sound shield

An improved test section for a supersonic or hypersonic wind tunnel is disclosed wherein the model tested is shielded from the noise normally radiated by the turbulent tunnel wall boundary layer. A vacuum plenum surrounds spaced rod elements making up the test chamber to extract some of the boundary layer as formed along the rod elements during a test to thereby delay the tendency of the rod boundary layers to become turbulent. Novel rod construction involves bending each rod slightly prior to machining the bent area to provide a flat segment on each rod for connection with the flat entrance fairing. Rods and fairing are secured to provide a test chamber incline on the order of 1 deg outward from the noise shield centerline to produce up to 65% reduction of the root mean square (rms) pressure over previously employed wind tunnel test sections at equivalent Reynolds numbers

An open question: Are topological arguments helpful in setting initial conditions for transport problems in condensed matter physics?

The tunneling Hamiltonian is a proven method to treat particle tunneling between different states represented as wavefunctions in many-body physics. Our problem is how to apply a wave functional formulation of tunneling Hamiltonians to a driven sine-Gordon system. We apply a generalization of the tunneling Hamiltonian to charge density wave (CDW) transport problems in which we consider tunneling between states that are wavefunctionals of a scalar quantum field. We present derived I-E curves that match Zenier curves used to fit data experimentally with wavefunctionals congruent with the false vacuum hypothesis. THe open question is whether the coefficients picked in both the wavefunctionals and the magnitude of the coefficents of the driven sine Gordon physical system should be picked by topological charge arguements that in principle appear to assign values that have a tie in with the false vacuum hypothesis first presented by Sidney ColemanComment: 17 pages, 4 figures (1a to 2b) on two pages. Specific emphasis on if or not topological arguements a la Trodden, Su et al add to formulation of condensed matter transport problem

Advanced Technology for Economical Dehumidification to Improve Indoor Air Quality

High humidity can have a detrimental effect on many aspects of indoor environments. Building materials, books, and records deteriorate more rapidly in humidity levels above 60% due to biodegradation. High humidity increases electrical costs by reducing the temperature required for occupant comfort. Fungal growth in humidities above 70% can have many detrimental health effects, depending on the particular species encountered [5,1]. In fact, high humidity is often an underlying cause of many air quality disorders that result in indoor air quality (IAQ) problems

Experimental and theoretical investigation of boundary-layer instability mechanisms on a swept leading edge at Mach 3.5

A brief outline of the experimental and theoretical investigation of boundary layer instability mechanisms on a swept leading edge at Mach 3.5 is presented. Transition is affected by wind tunnel noise only when roughness is present. Local bar-R sub * Reynolds number and k/eta sub * are useful correlation parameters for a wide range of free stream Mach numbers. Stability theory is in good agreement with the experimental cross flow vortex wavelength. These conclusions are briefly discussed

Semantic Differential Relationships as a Determinant of Clustering

In the past, clustering research has focused primarily on the effect of pre-experimental associations and/or conceptual relationships on clustering in free recall. The present study marks a departure from this trend in that it was designed to determine under what conditions SD relationships among task-items would mediate clustering

A New S-S' Pair Creation Rate Expression Improving Upon Zener Curves for I-E Plots

To simplify phenomenology modeling used for charge density wave (CDW)transport, we apply a wavefunctional formulation of tunneling Hamiltonians to a physical transport problem characterized by a perturbed washboard potential. To do so, we consider tunneing between states that are wavefunctionals of a scalar quantum field. I-E curves that match Zener curves - used to fit data experimentally with wavefunctionals congruent with the false vacuum hypothesis. This has a very strong convergence with electron-positron pair production representations.The similarities in plot behavior of the current values after the threshold electric field values argue in favor of the Bardeen pinning gap paradigm proposed for quasi-one-dimensional metallic transport problems.Comment: 22 pages,6 figures, and extensive editing of certain segments.Paper has been revised due to acceptance by World press scientific MPLB journal. This is word version of file which has been submitted to MPLBs editor for final proofing. Due for publication perhaps in mid spring to early summer 200

Design and fabrication requirements for low noise supersonic/hypersonic wind tunnels

A schematic diagram of the new proposed Supersonic Low Disturbance Tunnel (SLDT) is shown. Large width two dimensional rapid expansion nozzles guarantee wide quiet test cores that are well suited for testing models at large angle of attack and for swept wings. Hence, this type of nozzle will be operated first in the new proposed large scale SLDT. Test results indicate that the surface finish of pilot nozzles is critical. The local roughness Reynolds number criteria R sub k is approx. = 10 will be used to specify allowable roughness on new pilot nozzles and the new proposed tunnel. Experimental data and calculations for M = 3.0, 3.5, and 5.0 nozzles give N-factors from 6 to 10 for transition caused by Goertler vortices. The use of N is approx. = 9.0 for the Goertler instability predicts quiet test cores in the new M = 3.5 and M = 6.0 axisymmetric long pilot nozzles that are 3 to 4 times longer than observed in the test nozzles to date. The new nozzles utilize a region of radial flow which moves the inflection point far downstream and delays the onset and amplification of the Goertler vortices

The Influence of Magnetic Field Geometry on the Evolution of Black Hole Accretion Flows: Similar Disks, Drastically Different Jets

Because the magneto-rotational instability is capable of exponentially amplifying weak preexisting magnetic fields, it might be hoped that the character of the magnetic field in accretion disks is independent of the nature of the seed field. However, the divergence-free nature of magnetic fields in highly conducting fluids ensures that their large-scale topology is preserved, no matter how greatly the field intensity is changed. By performing global two-dimensional and three-dimensional general relativistic magnetohydrodynamic disk simulations with several different topologies for the initial magnetic field, we explore the degree to which the character of the flows around black holes depends on the initial topology. We find that while the qualitative properties of the accretion flow are nearly independent of field topology, jet-launching is very sensitive to it: a sense of vertical field consistent for at least an inner disk inflow time is essential to the support of strong jets.Comment: 42 pages; 17 figures; Accepted for publication in ApJ (some new discussion and 2 new figures