113,851 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
Updatable Probabilistic Evaluation of Failure Rates of Mechanical Components in Power Take-Off Systems of Tidal Stream Turbines
No full textThis paper presents a method for the probabilistic evaluation of the failure rates of mechanical components in a typical power take-off (PTO) system of a horizontal-axis tidal stream turbine (HATT). The method is based on a modification of the method of the influence factors, when base failure rates, relevant influence factors and, subsequently, resulting failure rates are treated as random variables. The prior (i.e., initial) probabilistic distribution of the failure rates of a HATT component is generated using data for similar components from other industries, while taking into account actual characteristics of the component and site-specific operating and environmental conditions of the HATT. A posterior distribution of the failure rate is estimated numerically based on a Bayesian approach as new information about the component performance in an operating HATT becomes available. The posterior distribution is then employed to obtain the updated mean and lower and upper confidence limits of the failure rate. The proposed method is illustrated by applying it to the evaluation of the failure rates of two key components of the PTO system of a typical HATT—main seal and main bearing. In particular, it is shown that uncertainty associated with the method itself has a major influence on the failure rate evaluation. The proposed method is useful for the reliability assessment of both PTO designs of new HATTs and PTO systems of operating HATTs
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
Metabolites of Marine Sediment-Derived Fungi: Actual Trends of Biological Activity Studies
No full textMarine sediments are characterized by intense degradation of sedimenting organic matter in the water column and near surface sediments, combined with characteristically low temperatures and elevated pressures. Fungi are less represented in the microbial communities of sediments than bacteria and archaea and their relationships are competitive. This results in wide variety of secondary metabolites produced by marine sediment-derived fungi both for environmental adaptation and for interspecies interactions. Earlier marine fungal metabolites were investigated mainly for their antibacterial and antifungal activities, but now also as anticancer and cytoprotective drug candidates. This review aims to describe low-molecular-weight secondary metabolites of marine sediment-derived fungi in the context of their biological activity and covers research articles published between January 2016 and November 2020
MOLECULAR LINE LISTS FOR SCANDIUM AND TITANIUM HYDRIDE USING THE DUO PROGRAM
No full textTransition-metal-containing (TMC) molecules often have very complex electronic spectra because of their large number of low-lying, interacting electronic states, of the large multi-reference character of the electronic states and of the large magnitude of spin-orbit and relativistic effects. As a result, fully ab initio calculations of line positions and intensities of TMC molecules have an accuracy which is considerably worse than the one usually achievable for molecules made up by main-group atoms only. In this presentation we report on new theoretical line lists for scandium hydride ScH and titanium hydride TiHfootnote{L. Lodi, S. N. Yurchenko and J. Tennyson, Mol. Phys. (Handy special issue) in press.}. Scandium and titanium are the lightest transition metal atoms and by virtue of their small number of valence electrons are amenable to high-level electronic-structure treatments and serve as ideal benchmark systems. We report for both systems energy curves, dipole curves and various coupling curves (including spin-orbit) characterising their electronic spectra up to about 20 000 cm-1. Curves were obtained using Internally-Contracted Multi Reference Configuration Interaction (IC-MRCI) as implemented in the quantum chemistry package MOLPRO. The curves where used for the solution of the coupled-surface ro-vibronic problem using the in-house program DUO footnote{S. N. Yurchenko, L. Lodi, J. Tennyson and A. V. Stolyarov, Computer Phys. Comms., to be submitted.}. DUO is a newly-developed, general program for the spectroscopy of diatomic molecules and its main functionality will be described.
The resulting line lists for ScH and TiH are made available as part of the Exomol project footnote{J. Tennyson and S. N. Yurchenko, Mon. Not. R. Astr. Soc. 2012, 425, 21. See also www.exomol.com.}.Made available in DSpace on 2016-01-05T20:01:47Z (GMT). No. of bitstreams: 3
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Francouzská národní fronta a její současná pozice v francouzské politici
No full textOd samého založení Francouzské národní fronty (FN) v roce 1972 politikem Jeanem Marie Le Penem obsadila FN značnou pozici na francouzské politické scéně. Tato magisterská práce je zaměřená na analýzu ideologického a volebního rozvoje FN. Kritéria radikální pravicové strany jsou aplikované na FN, abychom zjistili, zda je možné považovat FN za součást radikální pravice. Hlavní důraz je kladen na současný rozvoj FN, jenž je spojen s předáním moce Marine Le Penové a účastí FN v loňských volbách. Tato práce potvrzuje, že nový vůdce nepřinesl žádné významné změny ideologie FN, přesto určité změny ve vnímaní FN voličů jsou. Voliči, jejichž počet neustále roste, nepovažují FN za nebezpečí pro francouzskou demokracii.From its foundation in 1972 by charismatic politician Jean-Marie Le Pen the French National Front (FN) has been occupying an prominent position in the French political scene. This thesis aims at analysis of the ideological as well as electoral development of the FN. The criteria of the extreme right party family are applied to the FN in order to reveal whether the FN could be considered part of the party family. The main focus is on the recent development of the FN connected with the transition of power to Marine Le Pen and FN's participation in the 2012 elections. It is argued that the change of leadership did not lead to any substantial shifts in the party's ideology. However, there are some changes in the voters's perception of the FN. Increasingly more French voters do not consider the FN a danger to French democracy
Non-adiabatic Calculations Of Spectra Of Open-shell Diatomic Molecules
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Non-adiabatic couplings (NACs) or derivative couplings (DDRs) between nearly degenerate states can be significant or even divergent. NACs arise from nuclear gradients of electronic wave functions around avoided crossings between adiabatic potential energy curves. Large values of NACs result in strong interaction between corresponding adiabatic states, making the adiabatic approximation invalid. In this work we consider NACs in the case of diatomic open-shell molecules and implement a diabatizaton methodology in the variatonal code \textsc{Duo}.\footnote{S.~N. Yurchenko, L.~Lodi, J.~Tennyson, A.~V. Stolyarov, \emph{Comput. Phys. Commun.}, 2016, \textbf{202}, 262 -- 275; publicly available at \textit{https://github.com/ExoMol}.} The methodology is based on a unitary transformation to the so-called quasi-diabatic states defined to provide smooth (with respect to nuclear coordinates) behaviour of different properties, such as spin-orbit curves, (transition) dipole moment curves etc. As example, rovibronic calculations of the electronic spectra of yttrium oxide, YO,\footnote{A.~N. Smirnov, V.~G. Solomonik, S.~N. Yurchenko, J.~Tennyson, \emph{Phys. Chem. Chem. Phys.}, 2019, \textbf{21}, 22794--22810.} in the quasi-diabatic representation will be presented.
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author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
RAZLIKE V ZALETNIH HITROSTIH NA PRESKOKU PRI VRHUNSKIH TELOVADCIH IN TELOVADKAH
No full textThe aim of this study was to compare differences in run-up velocity between Handsprings, Tsukahara and Yurchenko entry on vault. A sample consisted of 48 jumps performed on vault, 19 Handsprings, 17 Tsukahara and 12 Yurchenko entry on vault. Data were collected on a World Cup competition held in Osijek, 2017. Run-up velocity was measured by speed radar gun (Stalker ATS, S PRO II). Descriptive statistic was calculated for all variables and differences in run-up velocity were determined by one-way ANOVA and Bonferroni post-hoc test at the level of statistical significance at p<.05. Average run-up velocity at Handspring entry was 8,06 m/s, Tsukahara, 8,06 m/s and Yurchenko entry on vault table was 7,66 m/s. ANOVA showed that exist statistical significant differences in run-up velocity between handspring and Yurchenko and between Tsukahara and Yurchenko entry. The results of this study indicated that different entry on vault table has different run-up velocity, which will help coaches and scientists to improve the vault technique.Namen študije je bil primerjati razlike v hitrosti zaleta med skoki vrste premet, cukahara in jurčenko. Vzorec je sestavljalo 48 skokov, izvedenih na tekmovanju, od tega je bilo, 19 premetov, 17 cukahar in 12 jurčenkov. Podatki so bili zbrani na tekmovanju svetovnega pokala v Osijeku, 2017. Hitrost zaleta je bila izmerjena s hitrostnim radarjem (Stalker ATS, S PRO II). Opisna statistika je bila izračunana za vse spremenljivke in razlike v hitrosti naraščanja so bile določene z enosmerno ANOVA in Bonferronijevim preverjanjem na ravni pomembnosti pri p <.05. Povprečna hitrost zaleta pri premetu je bila 8,06 m / s, cukahari, 8,06 m / s in jurčenku 7,66 m / s. ANOVA je pokazala, da obstajajo pomembne razlike v hitrosti zaleta med premetom in jurčenkom ter med cukarao in jurčenkom. Rezultati te študije so pokazali, da ima drugačna vrsta skoka drugačno hitrost pri zaletu, kar bo vaditeljem in raziskovalcem pomagalo izboljšati tehniko preskoka
Influence of various winter wheat variety properties on productivity variability
No full textShakaliі, S. M., Bahan, А. V., Yurchenko, S. O., & Golovash, L. M. (2022). Influence of
various winter wheat variety properties on productivity variability. Bulletin of
Poltava State Agrarian Academy, (1), 11–17. doi: 10.31210/visnyk2022.01.0
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