131,615 research outputs found
ExoMol line lists - III. An improved hot rotation-vibration line list for HCN and HNC
No full textA revised rotation-vibration line list for the combined hydrogen cyanide (HCN)/hydrogen isocyanide (HNC) system is presented. The line list uses ab initio transition intensities calculated previously and extensive data sets of recently measured experimental energy levels. The resulting line list has significantly more accurate wavelengths than previous ones for these systems. An improved value for the separation between HCN and HNC is adopted, leading to an approximately 25 per cent lower predicted thermal population of HNC as a function of temperature in the key 2000 to 3000 K region. Temperature-dependent partition functions and equilibrium constants are presented. The line lists are validated by comparison with laboratory spectra and are presented in full as supplementary data to the article and at www.exomol.com
ExoMol line lists-IV. The rotation-vibration spectrum of methane up to 1500 K
No full textA new hot line list is calculated for CH in its ground electronic state. This line list, called 10to10, contains 9.8 billion transitions and should be complete for temperatures up to 1500 K. It covers the wavelengths longer than 1 μm and includes all transitions to upper states with energies below hc · 18 000 cm and rotational excitation up to J = 39. The line list is computed using the eigenvalues and eigenfunctions of CH obtained by variational solution of the Schrödinger equation for the rotation-vibration motion of nuclei employing program TROVE and a new 'spectroscopic' potential energy surface (PES) obtained by refining an ab initio PES (CCSD(T)-F12c/aug-cc-pVQZ) through least-squares fitting to the experimentally derived energies with J = 0-4 and a previously reported ab initio dipole moment surface (CCSD(T)-F12c/aug-cc-pVTZ). Detailed comparisons with other available sources of methane transitions including HITRAN, experimental compilations and other theoretical line lists show that these sources lack transitions both higher temperatures and near-infrared wavelengths. The 10to10 line list is suitable for modelling atmospheres of cool stars and exoplanets. It is available from the CDS data base as well as at www.exomol.com
The Darby-Lewis dataset for 9Be2H
No full textThe dataset is an archive of ExoMol page, https://exomol.com/data/molecules/BeH/9Be-2H/Darby-Lewis. Please check the reference details according to the following description or directly from the website.Definitions file:9Be-2H__Darby-Lewis.defRoot references for ExoMol database: 1. J. Tennyson, S.N. Yurchenko A.F. Al-Refaie, V.H.J. Clark, K.L. Chubb,E.K. Conway, A. Dewan, M.N. Gorman, C. Hill, A.E. Lynas-Gray, T. Mellor, L.K. McKemmish, A. Owens, O.L. Polyansky, M. Semenov, W. Somogyi, G. Tinetti, A. Upadhyay, I. Waldmann, Y. Wang, S. Wright and O.P. Yurchenko, The 2020 release of the ExoMol database: molecular line lists for exoplanet and other hot atmospheres, J. Quant. Spectrosc. Rad. Transf., 255, 107228 (2020).[https://doi.org/10.1016/j.jqsrt.2020.107228.]Darby-Lewis: line listDarby-Lewis line list for BeH in its X and A electronic states using the Duo program.: 9Be-2H__Darby-Lewis.trans.bz2 Transition file for the Darby-Lewis line list for (9Be)(2H) 9Be-2H__Darby-Lewis.states.bz2 States file for the Darby-Lewis line list for (9Be)(2H)References: 1. Darby-Lewis, D., Tennyson, J., Lawson, K. D., Yurchenko, S. N., Stamp, M. F., Shaw, A., Brezinsek, S., JET Contributors, "Synthetic spectra of BeH, BeD and BeT for emission modeling in JET plasmas", J. Phys. B At. Mol. Opt. Phys. 51, 185701 (2018). [https://doi.org/10.1088/1361-6455/aad6d0][18DaTeLa.BeH]Darby-Lewis: partition functionDarby-Lewis line list for BeH in its X and A electronic states using the Duo program.: 9Be-2H__Darby-Lewis.pf Partition function of (9Be)(2H) generated using the Darby-Lewis line listReferences: 1. Darby-Lewis, D., Tennyson, J., Lawson, K. D., Yurchenko, S. N., Stamp, M. F., Shaw, A., Brezinsek, S., JET Contributors, "Synthetic spectra of BeH, BeD and BeT for emission modeling in JET plasmas", J. Phys. B At. Mol. Opt. Phys. 51, 185701 (2018). [https://doi.org/10.1088/1361-6455/aad6d0][18DaTeLa.BeH
Influence of predefined angle of attack on piezoelectric energy harvesting from transverse galloping of different bluff bodies
No full textThe development of smart Internet-of-Things (IoT) solutions requires sensor nodes to be placed at different locations of monitored structures. Wireless solutions are quite attractive because of their simplicity although requiring for local energy supply. In this context, this study investigates the influences of the predefined angle of attack on the piezoelectric energy harvesting based on transverse galloping of different bluff bodies. The investigation is based on a lumped electro-aero-mechanical model with linear electrical and mechanical properties and nonlinear aerodynamic forces evaluated using the quasi-steady theory. The performances of energy harvesters with six different bluff bodies are analyzed at various predefined angles of attack: four rectangular cross-sections with different width-to-height ratios (i.e., b/d), one trapezium section, and one equal angle section. The main purpose is to understand the sensitivity of various bluff body-based energy harvesters on the predefined angle of attack, and further suggest a bluff body-based energy harvester that is robust to the predefined angle of attack. The results show that the response is quite dependent on the characteristic of the electro-mechanical system and the bluff body cross-section and angle of attack. In all cases, the load resistance should be tuned to maximize energy production. The largest vibration amplitude (i.e., largest power output) is predicted for the rectangular bluff body with b/d = 1.0 at a 0° angle of attack. However, its performances are quite dependent on the angle of attack, resulting in a zero-power output for an angle of attack exceeding 4°. A rectangular bluff body with b/d within 1.62 to 2.5 exhibits a reduced energy production compared with b/d = 1.0 at a 0° angle of attack but better robustness varying the angle of attack. Finally, the trapezium and the angle bluff bodies are not suitable for energy harvesting due to their very high onset velocities within the considered range of angles of attack
Exomol: molecular line list for exoplanets and other atmospheres
No full textThe discovery of extrasolar planets is one of the major scientific
advances of the last two decades. Thousands of planets have now been
detected and astronomers are beginning to characterize their
composition and physical characteristics. To do this requires a huge
quantity of spectroscopic data most of which are not available from
laboratory studies. The ExoMol project [1] is generating a
comprehensive solution to this problem by providing spectroscopic
data on all the molecular transitions of importance in the
atmospheres of exoplanets. These data are widely applicable to other
problems such studies on cool stars, brown dwarfs and circumstellar
environments as well as industrial and technological problems on earth.
ExoMol employs a mixture of first
principles and empirically tuned quantum mechanical methods
to compute comprehensive and very large rotation–vibration and
rovibronic line lists. Results span a variety of closed
(NaH, SiO, PN, NaCl, KCl, CS) and open (BeH, MgH, CaH, AlO, VO) shell
diatomics to triatomics (HCN/HNC, SO, HS, H),
tetratomics (HCO, PH, SO, HO), plus methane [2] and nitric acid [3]. This has led directly to the detection of new species
in the atmospheres of exoplanets [4]. A new comprehensive
data release has just been completed [5]. Progress on and future
prospects of the project will be summarised.
\bibliographystyle{default}
\begin{thebibliography}{5}
\bibitem{jt528} J. Tennyson, S.~N. Yurchenko, Mon. Not. R. astr. Soc., 425, 21, 2012.
\bibitem{jt572} S.~N. Yurchenko, J. Tennyson, J. Bailey, M.~D.~J. Hollis, G Tinetti, Proc. Nat. Acad. Sci., 111, 9379, 2014.
\bibitem{jt614} A.~I. Pavlyuchko, S.~N. Yurchenko, J. Tennyson, Mon. Not. R. astr. Soc., 452, 1702, 2015.
\bibitem{jt629} A. Tsiaras {\it et al}, Astrophys. J., in press.
[5] J. Tennyson {\it et al}, J. Mol. Spectrosc., in press.
\end{thebibliography}Made available in DSpace on 2017-01-26T21:38:31Z (GMT). No. of bitstreams: 3
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Previous issue date: 2016-06-2
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
A predicted optimal performance of the Yurchenko layout vault in women's artistic gymnastics
No full textThe Yurchenko layout vault is the base vault from which more advanced forms of the Yurchenko family of vaults have evolved. The purpose of the study was to predict an individual's optimal Yurchenko layout vault by modifying selected critical mechanical variables. The gymnast's current performance characteristics were determined using the Peak-Motus video analysis system. Body segment parameters were determined using the elliptical zone mathematical modeling technique of Jensen (1978). A 5-segment computer simulation model was personalized for the gymnast comprising the hands, upper limbs, upper trunk, lower trunk, and lower limbs. Symmetry was assumed, as the motion was planar in nature. An objective function was identified which translated the subjective points-evaluation scheme of the Federation of International Gymnastics (FIG) Code of Points to an analytic expression that was mathematically tractable. The objective function was composed of performance variables that, if maximized, would result in minimal points being deducted and bonus points being allocated. A combined optimal control and optimal parameter selection approach was applied to the model to determine an optimum technique. The predicted optimal vault displayed greater postflight amplitude and angular momentum when compared with the gymnast's best trial performance. Increased angular velocity, and consequently greater angular momentum at impact and greater shoulder flexion angle at impact with the horse, were related with this optimum technique. The impact phase therefore serves to increase the angular momentum during horse contact. Since the optimized parameters at impact with the horse were within the accepted physical capacity limits observed for the individual, the predicted vault is viable.Griffith Health FacultyNo Full Tex
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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