2,511 research outputs found
Addendum to SSV Generic OFT First Stage Ascent Base Convective Heating Environments
Convective environments for OFT Mission C are presented in graphs for first stage convective heating to the internal surfaces of the OMS nozzle, to the aft facing 8 and 9 RCS nozzles, and to the base (trailing edge) of the vertical tail
Vector Casimir effect for a D-dimensional sphere
The Casimir energy or stress due to modes in a D-dimensional volume subject
to TM (mixed) boundary conditions on a bounding spherical surface is
calculated. Both interior and exterior modes are included. Together with
earlier results found for scalar modes (TE modes), this gives the Casimir
effect for fluctuating ``electromagnetic'' (vector) fields inside and outside a
spherical shell. Known results for three dimensions, first found by Boyer, are
reproduced. Qualitatively, the results for TM modes are similar to those for
scalar modes: Poles occur in the stress at positive even dimensions, and cusps
(logarithmic singularities) occur for integer dimensions . Particular
attention is given the interesting case of D=2.Comment: 20 pages, 1 figure, REVTe
Modular space station phase B extension preliminary system design. Volume 2: Operations and crew analyses
All analyses and tradeoffs conducted to establish the MSS operations and crew activities are discussed. The missions and subsystem integrated analyses that were completed to assure compatibility of program elements and consistency with program objectives are presented
SSV Generic OFT first stage ascent base convective heating environments
Space Shuttle Vehicle (SSV) base convective heating environments during the recirculated flow time segment of first stage ascent were determined for the Generic OFT trajectory and performance conditions. These environments are presented in the attachments as cold wall convective heat transfer coefficients for individual or groups of design points for all affected SSV base surfaces. Two gas recovery temperatures applicable to upper and lower base region surfaces are also included. The environments were based upon magnitudes and trends from analysis of data taken during Base Heating Tests IH-39, IH-75, and IH-83. The plume heating trajectory and performance data were supplied by Rockwell International for both the OFT-1 Generic Mission A and Mission C
Casimir effect for a -dimensional sphere
The Casimir force on a -dimensional sphere due to the confinement of a
massless scalar field is computed as a function of , where is a
continuous variable that ranges from to . The dependence of
the force on the dimension is obtained using a simple and straightforward
Green's function technique. We find that the Casimir force vanishes as ( non-even integer) and also vanishes when is a negative even
integer. The force has simple poles at positive even integer values of .Comment: 22 pages, REVTeX, 4 uuencoded figures, OKHEP-94-0
The Chesapeake Bay: A Study of Present and Future Water Quality and Its Ecological Effects Volume II: Analysis and Projection of Ecological Conditions
Petrology and Geochemistry of the Silver Plume-Age Plutons of the Southern and Central Wet Mountains, Colorado.
The 1.43 billion-year-old Silver Plume-age intrusive complex of the central and southern Wet Mountains, Colorado, is subdivided into six units. In inferred order of intrusion, these include: the San Isabel batholith, the granite of Cliff Creek, the granite of Williams Creek, the granite of Bear Creek, the Wixson Divide pluton, and the granite of the Mount Tyndall quadrangle. All rocks are metaluminus to mildly peraluminus, calc-alkaline, and modally range from melanocratic biotite-hornblende-rich granite to leucocratic alaskite. The biotite-rich granites are non-eutectic and crystallized at a temperature of 710(DEGREES)C to 850(DEGREES)C. The leucocratic granites are eutectic and crystallized between 650(DEGREES)C and 700(DEGREES)C. The depth of emplacement is mesozone to catazone, representing an emplacement depth less than 17 kilometers, with a load pressure of less than 4600 bars. The rocks have undergone pre-, syn-, and post-emplacement crystallization followed by late stage recrystallization, mylonization, and potassium metasomatism. Field, modal, and chemical characteristics of the Silver Plume granites, are not clearly indicative of any single model of granite formation. The granites closely resemble I-type or S-type granites. However, the plutons appear to have an anoroginic origin. This seemingly paradoxical situation may suggest that the magma produced during the anorogenic Silver Plume Disturbance-Thermal Event inherited much of its oroginic character from the melting of rocks generated during an earlier event
Water-in-air droplet formation in plasma bonded microchannels fabricated by Shrinky-Dink® lithography
Thesis (M.S.) University of Alaska Fairbanks, 2011This thesis presents the first work on water-in-air droplet microfluidics. Polymeric microchannels were prototyped to illustrate water droplet formation in air by the T-junction meditated design. The first part of the thesis is on the proof of using unfiltered air as the process gas for plasma-assisted bonding of polydimethylsiloxane (PDMS) microchannels. A series of bilayered PDMS prototypes were plasma bonded under various plasma treatment parameters to determine the optimal settings for high-strength bonding. Pressure rupture tests were conducted to measure the bonding interface strength, which were shown to be as high as 135 psi. The second part of the thesis illustrates the formation and dispersion of water droplets in a continuous air flow in microchannels, and discusses the mechanisms of how droplets are formed. The Shrinky Dinks lithography and plasma-assisted bonding were used to prototype leakage-free microcbannels for testing droplet production. Droplets are formed under the competition between the fluid viscosity and surface tension forces. The channel dimensions and the fluid flow rates dictate the mechanism of droplet formation. The major finding is that the droplet length increases and droplet velocity decreases with increasing water flow rates, but some droplets were not formed at the T-Junction. These findings are discussed.Alaska NASA EPSCoR Progra
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