Etvs University

Budapest, Hungary

Etvs University

Budapest, Hungary
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Fbri C.,Etvs University | Mtyus E.,Etvs University | Mtyus E.,ETH Zurich | Furtenbacher T.,Etvs University | And 6 more authors.
Journal of Chemical Physics | Year: 2011

A variational quantum mechanical protocol is presented for the computation of rovibrational energy levels of semirigid molecules using discrete variable representation of the Eckart-Watson Hamiltonian, a complete, exact inclusion of the potential energy surface, and selection of a vibrational subspace. Molecular symmetry is exploited via a symmetry-adapted Lanczos algorithm. Besides symmetry labels, zeroth-order rigid-rotor and harmonic-oscillator quantum numbers are employed to characterize the computed rovibrational states. Using the computational molecular spectroscopy algorithm presented, a large number of rovibrational states, up to J 50, of the ground electronic state of the parent isotopologue of ketene, H212C12C16O, were computed and characterized. Based on 12 references, altogether 3982 measured and assigned rovibrational transitions of H2 12C12C16O have been collected, from which 3194 were validated. These transitions form two spectroscopic networks (SN). The ortho and the para SNs contain 2489 and 705 validated transitions and 1251 and 471 validated energy levels, respectively. The computed energy levels are compared with energy levels obtained, up to J 41, via an inversion protocol based on this collection of validated measured rovibrational transitions. The accurate inverted energy levels allow new assignments to be proposed. Some regularities and irregularities in the rovibrational spectrum of ketene are elucidated. © 2011 American Institute of Physics.

Gyollai I.,Etvs University | Gyollai I.,University of Vienna | Gucsik A.,Osaka University | Gucsik A.,Max Planck Institute for Chemistry | And 5 more authors.
Spectroscopy Letters | Year: 2012

Two diamond-bearing meteorites (ALH-77257 and ALH-78113) were investigated by petrographic microscope and micro-Raman spectroscopy. The meteoritic diamonds can be found in fractures or veins cross-cutting the original minerals (olivine, pyroxene, feldspar) and inside the host minerals. The micro-Raman spectral features of microdiamonds in two studied meteorites are very similar to each other. The diamond peak was found at 1329 in ALH-77257 and 1332cm 1 in ALH-78113. Hexagonal diamond was not present. However, we observed the D and G bands of graphite or amorphous carbon at 1322 and 1582cm 1 wavenumbers, indicating an origin of the meteoritic microdiamonds by magmatic processes. © 2012 Copyright Taylor and Francis Group, LLC.

Collier A.B.,Hermanus Magnetic Observatory | Collier A.B.,University of KwaZulu - Natal | Lichtenberger J.,Etvs University | Clilverd M.A.,British Antarctic Survey | And 2 more authors.
Journal of Geophysical Research: Space Physics | Year: 2011

The accepted mechanism for whistler generation implicitly assumes that the causative lightning stroke occurs within reasonable proximity to the conjugate foot point of the guiding magnetic field line and that nighttime whistlers are prevalent because of low transionospheric attenuation. However, these assumptions are not necessarily valid. In this study we consider whistler observations from Rothera, a station on the Antarctic Peninsula, and contrast their occurrence with global lightning activity from the World Wide Lightning Location Network. The correlation of one-hop whistlers observed at Rothera with global lightning yields a few regions of significant positive correlation. The most probable source region was found over the Gulf Stream, displaced slightly equatorward from the conjugate point. The proximity of the source region to the conjugate point is in accord with the broadly accepted whistler production mechanism. However, there is an unexpected bias toward oceanic lightning rather than the nearby continental lightning. The relationship between the diurnal pattern of the Rothera whistlers and the conjugate lightning exhibits anomalous features which have yet to be resolved: the peak whistler rate occurs when it is daytime at both the source and the receiver and when source lightning activity is at its lowest. As a result, we propose that preferential whistler-wave amplification in the morning sector is a possible cause of the high whistler occurrence, although this does not account for the bias toward oceanic lightning. Copyright 2011 by the American Geophysical Union.

Delport B.,University of KwaZulu - Natal | Collier A.B.,University of KwaZulu - Natal | Lichtenberger J.,Etvs University | Rodger C.J.,University of Otago | And 3 more authors.
Journal of Geophysical Research: Space Physics | Year: 2012

On 4 August 2010 a moderate geomagnetic storm occurred with minimum Dst of-65 nT and maximum Kp of 7-. Shortly after the onset of this storm, VLF chorus was observed at Marion Island (L = 2.6). Over time the spectral structure of the chorus transformed into a hiss band spanning the same frequency range. The observation of overlapping chorus and hiss suggests that Marion Island was close to the plasmapause at the time of this event, and provides ground-based observational confirmation of the generation mechanism of plasmaspheric hiss from chorus waves outside of the plasmasphere. Chorus observations at Marion Island were not common during this period of the solar cycle and so this event was investigated in detail. The geomagnetic conditions are discussed and geosynchronous particle data and broadband data from two other stations are presented. Empirical models are employed to predict the location of the plasmapause, and its location is inferred from a knee whistler recorded at Dunedin, New Zealand. These show that Marion Island is in the vicinity of the plasmapause during the event. The event is also compared to chorus observed at similar L after the Halloween storms of 2003. The rarity of the chorus observation is quantified using DEMETER VLF data. The DEMETER data, along with the various ground based VLF measurements, allows us to infer temporal and spatial variations in the chorus source region. © 2012. American Geophysical Union. All Rights Reserved.

Kzmr M.,Etvs University | Taborosi D.,University of Guam
Journal of Coastal Research | Year: 2012

A rapid, single-user profiling method for rocky shores is described. The Leica Disto D8 handheld laser distance meter measures distance up to 100 m and inclination in 360°. It automatically calculates horizontal distance and vertical elevation. Memory storage accommodates data for 30 measurement points, allowing easy plotting of shore profiles. This technique allows even inaccessible, dangerous, and overhanging cliff faces to be evaluated faithfully and within minutes. It is a major improvement over standard methods that often involve risky coasteering and climbing. Examples are given from marine notches in Thailand. © 2012 Coastal Education & Research Foundation.

Szenczi P.,Etvs University | Bnszegi O.,Etvs University | Bnszegi O.,Hungarian Academy of Sciences | Dcs A.,Etvs University | And 6 more authors.
Journal of Mammalogy | Year: 2011

Mound-building mice (Mus spicilegus) construct large mounds of soil and plant material in autumn, where juvenile animals overwinter in groups without reproducing. The mounds have several functions, including food storage, thermoregulation, and protection from predators. We examined whether these mounds have food storage or thermoregulatory function. Mice used mainly seeds and ears of certain plants (Echinochloa sp., Chenopodium spp., and Setaria spp., depending on availability) as building materials, but microhistological analysis of mice feces revealed that the cached plants are not represented in their actual diet. By comparing the features of soil under the mound to neighboring random points we found that the mounds have water-insulating and thermoregulatory properties. We also found a positive correlation between the size of the mound, its vegetal content, and its effectiveness to lessen the impact of the harsh conditions of the outside environment. Mound size was dependent on the number of inhabitants, indicating that larger mounds are constructed by and shelter bigger groups. The existence of communal mound building thus can contribute greatly to successful overwintering and the relatively low fluctuation in population size in this species. © 2011 American Society of Mammalogists.

Szenes A.,Etvs University | Pl G.,Etvs University
DNA Research | Year: 2012

The recently published discrete mathematical method, extended consensus partition (ECP), identifies nucleotide types at each position that are strictly absent from a given sequence set, while occur in other sets. These are defined as discriminating elements (DEs). In this study using the ECP approach, we mapped potential hidden identity elements that discriminate the 20 different tRNA identities. We filtered the tDNA data set for the obligatory presence of well-established tRNA features, and then separately for each identity set, the presence of already experimentally identified strictly present identity elements. The analysis was performed on the three kingdoms of life. We determined the number of DE, e.g. the number of sets discriminated by the given position, for each tRNA position of each tRNA identity set. Then, from the positional DE numbers obtained from the 380 pairwise comparisons of the 20 identity sets, we calculated the average excluding value (AEV) for each tRNA position. The AEV provides a measure on the overall discriminating power of each position. Using a statistical analysis, we show that positional AEVs correlate with the number of already identified identity elements. Positions having high AEV but lacking published identity elements predict hitherto undiscovered tRNA identity elements. © The Author 2012.

Pollner P.,Etvs University | Palla G.,Etvs University | Vicsek T.,Etvs University
Physica A: Statistical Mechanics and its Applications | Year: 2010

We study the behavior of the clustering coefficient in tagged networks. The rich variety of tags associated with the nodes in the networks we considered provide additional relevant information about the entities represented by the nodes. Such specific features can be important for practical applications like searching in the networks. Here we examine how the clustering coefficient changes when narrowing the network to a subgraph associated with a given tag, and how it correlates with various other properties of the subgraph. A further question addressed in our paper is how the clustering coefficient of the individual nodes is affected by the tags on the node. We argue that this kind of analysis can be useful when one is aimed at a detailed description of the structure of large complex systems. © 2010 Elsevier B.V. All rights reserved.

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