10,664 research outputs found
Composition dependence of ion transport coefficients in gas mixtures
A simple momentum-transfer theory for the composition dependence of ion mobilities and diffusion coefficients in gas mixtures at arbitrary field strengths is corrected, extended, and compared with a similar theory based on momentum and energy transfer, and with results based on direct solution of the Boltzmann equation by Kihara's method. Final equations are recommended for predicting composition dependences, given only results on ion mobilities and diffusion coefficients in the pure component gases
Heavy Rainfall Warning Assessment Tool User Guide. Version 1.2
This report is a User Guide to a PC tool for assessing Heavy Rainfall Warnings. Development of the PC tool formed an important operational output of the Environment Agency and Met Office funded project: "Development of Rainfall Forecast Performance Monitoring Criteria. Phase 1: Development of Methodology and Algorithms" (Jones et al., 2003).
The Heavy Rainfall Warning (HRW) Assessment Tool is a toolkit for Microsoft Excel. The tool allows the user to configure an assessment framework for a particular format of Heavy Rainfall Warning, enter and save data for forecasts and ground-truths, and generate a range of performance measures and other statistics for new and previously saved data. Summary tables are presented using Excel's PivotTable feature, from which charts can also be generated.
Performance measures are provided to assess forecasts of heavy rainfall in continuous variable, categorical and probability form: these include bias, rmse, R-squared Efficiency, skill scores and the Continuous Brier Score
Perancangan Buku Company Profile Sebagai Media Promosi Vegas Conceptual Show
Perusahaan Vegas Conceptual Show ini berada di daerah Surabaya, Indonesia. Perusahaan Vegas Conceptual Show ini merupakan Perusahaan baru yang berkembang pesat di dalam pasarnya. Perusahaan ini bergerak di bidang penyedia jasa untuk entertainment conceptual show. Perusahaan Vegas Conceptual Show ini memiliki kelebihan sendiri yang membedakannya dari Perusahaan entertainment show yang lainnya, yaitu kelebihan mereka dalam menyediakan jasa conceptual showtime. Namun Perusahaan ini menyadari bahwa perlu adanya upaya mempromosikan nama mereka dan memberikan awareness kepada masyarakat terlebih kepada target audience mereka. Oleh karena itulah dibutuhkan media dan promosi yang dilakukan agar dapat mempromosikan dan meningkatkan awareness terhadap para target audience dari Perusahaan Vegas Conceptual Show ini
SCUBA - A submillimetre camera operating on the James Clerk Maxwell Telescope
The Submillimetre Common-User Bolometer Array (SCUBA) is one of a new
generation of cameras designed to operate in the submillimetre waveband. The
instrument has a wide wavelength range covering all the atmospheric
transmission windows between 300 and 2000 microns. In the heart of the
instrument are two arrays of bolometers optimised for the short (350/450
microns) and long (750/850 microns) wavelength ends of the submillimetre
spectrum. The two arrays can be used simultaneously, giving a unique
dual-wavelength capability, and have a 2.3 arc-minute field of view on the sky.
Background-limited performance is achieved by cooling the arrays to below 100
mK. SCUBA has now been in active service for over a year, and has already made
substantial breakthroughs in many areas of astronomy. In this paper we present
an overview of the performance of SCUBA during the commissioning phase on the
James Clerk Maxwell Telescope (JCMT).Comment: 14 pages, 13 figures (1 JPEG), Proc SPIE vol 335
Transport coefficients and cross sections for electrons in water vapour: comparison of cross section sets using an improved Boltzmann equation solution
This paper revisits the issues surrounding computation of electron transport properties in water vapour as a function of E/n0 (the ratio of the applied electric field to the water vapour number density) up to 1200 Td. We solve the Boltzmann equation using an improved version of the code of Ness and Robson [Phys. Rev. A 38, 1446 (1988)], facilitating the calculation of transport coefficients to a considerably higher degree of accuracy. This allows a correspondingly more discriminating test of the various electron–water vapour cross section sets proposed by a number of authors, which has become an important issue as such sets are now being applied to study electron driven processes in atmospheric phenomena [P. Thorn, L. Campbell, and M. Brunger, PMC Physics B 2, 1 (2009)] and in modeling charged particle tracks in matter [A. Munoz, F. Blanco, G. Garcia, P. A. Thorn, M. J. Brunger, J. P. Sullivan, and S. J. Buckman, Int. J. Mass Spectrom. 277, 175 (2008)]
Summary report on excavations at Tell Khaiber, an administrative centre of the Sealand period, 2013-2017
Excavations at Tell Khaiber by the Ur Region Archaeological Project have revealed a substantial building (hereafter the Public Building) dating to the mid-second millennium BC. The results are significant for several reasons: they shed light on Babylonian provincial administration; they reveal a previously unknown type of fortified monumental building; and they produced a provenanced, dated archive of the little-understood Sealand Dynasty. Here we give a summary of the main results, including the architecture and the material culture. There are also comments on the historical background, and a discussion of the form and function of the Public Building
Detection of Cosmic Microwave Background Structure in a Second Field with the Cosmic Anisotropy Telescope
We describe observations at frequencies near 15 GHz of the second 2x2 degree
field imaged with the Cambridge Cosmic Anisotropy Telescope (CAT). After the
removal of discrete radio sources, structure is detected in the images on
characteristic scales of about half a degree, corresponding to spherical
harmonic multipoles in the approximate range l= 330--680. A Bayesian analysis
confirms that the signal arises predominantly from the cosmic microwave
background (CMB) radiation for multipoles in the lower half of this range; the
average broad-band power in a bin with centroid l=422 (theta = 51') is
estimated to be Delta_T/T=2.1^{+0.4}_{-0.5} x 10^{-5}. For multipoles centred
on l=615 (theta =35'), we find contamination from Galactic emission is
significant, and constrain the CMB contribution to the measured power in this
bin to be Delta_T/T <2.0 x 10^{-5} (1-sigma upper limit). These new results are
consistent with the first detection made by CAT in a completely different area
of sky. Together with data from other experiments, this new CAT detection adds
weight to earlier evidence from CAT for a downturn in the CMB power spectrum on
scales smaller than 1 degree. Improved limits on the values of H_0 and Omega
are determined using the new CAT data.Comment: 5 pages, 5 figures (gif), submitted to MNRA
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