93,259 research outputs found
Solvation agent for disulfide precipitates from inhibited glycol-water solutions
Small additions /0.01 percent or less/ of triethanoloamine sodium sulfite adduct to mercapto benzothiazole inhibited glycol water heat transfer solutions containing disulfide precipitate produce marked reduction in amount of precipitate. Adduct is useful as additive in glycol base antifreezes and coolants
Prediction of friction coefficients for gases
Empirical relations are used for correlating laminar and turbulent friction coefficients for gases, with large variations in the physical properties, flowing through smooth tubes. These relations have been used to correlate friction coefficients for hydrogen, helium, nitrogen, carbon dioxide and air
Experimental local heat-transfer and average friction data for hydrogen and helium flowing in a tube at surface temperatures up to 5600 deg r
Heat transfer and average friction coefficients for hydrogen and helium flowing in tungsten tub
Effect of refining variables on the properties and composition of JP-5
Potential future problem areas that could arise from changes in the composition, properties, and potential availability of JP-5 produced in the near future are identified. Potential fuel problems concerning thermal stability, lubricity, low temperature flow, combustion, and the effect of the use of specific additives on fuel properties and performance are discussed. An assessment of available crudes and refinery capabilities is given
Cut-off Characterisation of Energy Spectra of Bright Fermi Sources: Current instrument limits and future possibilities
In this paper some of the brightest GeV sources observed by the Fermi-LAT
were analysed, focusing on their spectral cut-off region. The sources chosen
for this investigation were the brightest blazar flares of 3C~454.3 and 3C~279
and the Vela pulsar with a reanalysis with the latest Fermi-LAT software. For
the study of the spectral cut-off we first explored the Vela pulsar spectrum,
whose statistics in the time interval of the 3FGL catalog allowed strong
constraints to be obtained on the parameters. We subsequently performed a new
analysis of the flaring blazar SEDs. For these sources we obtained constraints
on the cut-off parameters under the assumption that their underlying spectral
distribution is described by a power-law with a stretched exponential cut-off.
We then highlighted the significant potential improvements on such constraints
by observations with next generation ground based Cherenkov telescopes,
represented in our study by the Cherenkov Telescope Array (CTA). Adopting
currently available simulations for this future observatory, we demonstrate the
considerable improvement in cut-off constraints achievable by observations with
this new instrument when compared with that achievable by satellite
observations.Comment: total number of pages 24, including 6 pages of references. Accepted
by Astroparticle Physic
Analysis of heat transfer and fluid friction for fully developed turbulent flow of supercritical water with variable fluid properties in a smooth tube
Recommended from our members
Robust Inference on Seasonal Unit Roots via a Bootstrap Applied to OECD Macroeconomic Series
Recent experimental results presented in Burridge and Taylor (2001a,b, and 2003) show that, as usually implemented, the Hylleberg et al. (1990) seasonal unit root tests can be rather liberal, with true level often substantially higher than nominal level. This effect is due to the presence of any of three things: data-based lag selection in the implementation of the tests, and either or both periodic heteroscedasticity and serial correlation in the driving shocks. Burridge and Taylor (2003) demonstrate that under experimental conditions a carefully implemented bootstrap substantially corrects test level without loss of power. The present study applies their technique to a large number of publicly available series, and demonstrates conclusively that the bootstrap produces less liberal, and, given the experimental results cited above, more reliable inference. We report results for Sweden, the UK and the US, which are typical of the fifteen countries in our panel. Other results, the GAUSS code, and raw data are all available at: www.staff.city.ac.uk/p.burridge
Demonstration of the feasibility of automated silicon solar cell fabrication
A study effort was undertaken to determine the process, steps and design requirements of an automated silicon solar cell production facility. Identification of the key process steps was made and a laboratory model was conceptually designed to demonstrate the feasibility of automating the silicon solar cell fabrication process. A detailed laboratory model was designed to demonstrate those functions most critical to the question of solar cell fabrication process automating feasibility. The study and conceptual design have established the technical feasibility of automating the solar cell manufacturing process to produce low cost solar cells with improved performance. Estimates predict an automated process throughput of 21,973 kilograms of silicon a year on a three shift 49-week basis, producing 4,747,000 hexagonal cells (38mm/side), a total of 3,373 kilowatts at an estimated manufacturing cost of 1.22 per watt
Exterior powers in Iwasawa theory
The Iwasawa theory of CM fields has traditionally concerned Iwasawa modules
that are abelian pro-p Galois groups with ramification allowed at a maximal set
of primes over p such that the module is torsion. A main conjecture for such an
Iwasawa module describes its codimension one support in terms of a p-adic
L-function attached to the primes of ramification. In this paper, we study more
general and potentially much smaller Iwasawa modules that are quotients of
exterior powers of Iwasawa modules with ramification at a set of primes over p
by sums of exterior powers of inertia subgroups. We show that the higher
codimension support of such quotients can be measured by finite collections of
p-adic L-functions under the relevant CM main conjectures.Comment: 41 pages, to appear in J. Eur. Math. So
- …