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Enumeration of diagonally colored Young diagrams
ádám Gyenge
Mathematics , 2015,
Abstract: In this note we give a new proof of a closed formula for the multivariable generating series of diagonally colored Young diagrams. This series also describes the Euler characteristics of certain Nakajima quiver varieties. Our proof is a direct combinatorial argument, based on Andrews' work on generalized Frobenius partitions. We also obtain representations of these series in some particular cases as infinite products.
Migration and Extension of Solar Active Longitudinal Zones
N. Gyenge,T. Baranyi,A. Ludmány
Physics , 2013, DOI: 10.1007/s11207-013-0424-3
Abstract: Solar active longitudes show a characteristic migration pattern in the Carrington coordinate system when they can be identified at all. By following this migration, the longitudinal activity distribution around the center of the band can be determined. The halfwidth of the distribution is found to be varying in Cycles 21 - 23, and in some time intervals it was as narrow as 20 - 30 degrees. It was more extended around maximum but it was also narrow when the activity jumped to the opposite longitude. Flux emergence exhibited a quasi-periodic variation within the active zone with a period of about 1.3 years. The path of the active longitude migration does not support the view that it might be associated with the 11-year solar cycle. These results were obtained for a limited time interval of a few solar cycles and, bearing in mind uncertainties of the migration path definition, are only indicative. For the major fraction of dataset no systematic active longitudes were found. Sporadic migration of active longitudes was identified only for Cycles 21 - 22 in the northern hemisphere and Cycle 23 in the southern hemisphere.
Variations of Solar Non-axisymmetric Activity
N. Gyenge,T. Baranyi,A. Ludmány
Physics , 2014,
Abstract: The temporal behaviour of solar active longitudes has been examined by using two sunspot catalogues, the Greenwich Photoheliographic Results (GPR) and the Debrecen Photoheliographic Data (DPD). The time-longitude diagrams of the activity distribution reveal the preferred longitudinal zones and their migration with respect to the Carrington frame. The migration paths outline a set of patterns in which the activity zone has alternating prograde/retrograde angular velocities with respect to the Carrington rotation rate. The time profiles of these variations can be described by a set of successive parabolae. Two similar migration paths have been selected from these datasets, one northern path during cycles 21 - 22 and one southern path during cycles 13 - 14, for closer examination and comparison of their dynamical behaviours. The rates of sunspot emergence exhibited in both migration paths similar periodicities, close to 1.3 years. This behaviour may imply that the active longitude is connected to the bottom of convection zone.
Non-homogeneous Behaviour of the Spatial Distribution of Macrospicules
N. Gyenge,S. Bennett,R. Erdélyi
Physics , 2015, DOI: 10.1007/s12036-015-9316-2
Abstract: In this paper the longitudinal and latitudinal spatial distribution of macrospicules is examined. We found a statistical relationship between the active longitude determined by sunspot groups and the longitudinal distribution of macrospicules. This distribution of macrospicules shows an inhomogeneity and non-axysimmetrical behaviour in the time interval from June $2010$ until December $2012$ covered by observations of the Solar Dynamic Observatory (SDO) satellite. The enhanced positions of the activity and its time variation has been calculated. The migration of the longitudinal distribution of macrospicules shows a similar behaviour as that of the sunspot groups.
Active Longitude and Solar Flare Occurrences
N. Gyenge,A. Ludmány,T. Baranyi
Physics , 2015,
Abstract: The aim of the present work is to specify the spatio-temporal characteristics of flare activity observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and Geostationary Operational Environmental Satellite (GOES) satellites in connection with the behaviour of the longitudinal domain of enhanced sunspot activity known as active longitude (AL). By using our method developed for this purpose, we identified the AL in every Carrington Rotation provided by the Debrecen Photoheliographic Data (DPD). The spatial probability of flare occurrence has been estimated depending on the longitudinal distance from AL in the northern and southern hemispheres separately. We have found that more than the 60\% of the RHESSI and GOES flares is located within $\pm 36^{\circ}$ from the active longitude. Hence, the most flare-productive active regions tend to be located in or close to the active longitudinal belt. This observed feature may allow predicting the geo-effective position of the domain of enhanced flaring probability. Furthermore, we studied the temporal properties of flare occurrence near the active longitude and several significant fluctuations were found. More precisely, the results of the method are the following fluctuations: $0.8$ years, $1.3$ years and $1.8$ years. These temporal and spatial properties of the solar flare occurrence within the active longitudinal belts could provide us enhanced solar flare forecasting opportunity.
BRINZAL: Una herramienta informática para la ense?anza integrada de conceptos de ecofisiología de especies le?osas y gestión forestal
Fernández,María Elena; Gyenge,Javier; Reque,José A;
Interciencia , 2008,
Abstract: the semi-empirical brinzal 1.0 model, a teaching innovation simulating carbon fixation and its accumulation in the biomass of forestry plantations of any species is presented. the model is a tool that allows for evaluation of how different forest structures and management practices affect the microenvironment in which saplings live and how they respond according to its main morpho-physiological characteristics. brinzal 1.0 is, thus, a program conceived with the specific purpose of serving as a tool for college teaching in the forestry and biology fields, permitting to simulate at a stand level current silvicultural actions in forestry management (thinning, pruning, regeneration cuts, control of accompanying vegetation, etc.) and making it possible to understand sapling physiology under different micro-environmental conditions at its response to silvicultural practices. brinzal 1.0 has been developed as an application of the stella? program and is executable under the open access program isee player.
Efectos de la temperatura y la dieta en la biología de Eriopis connexa (Germar) (Coleoptera: Coccinellidae)
Gyenge, Javier E.;Edelstein, Julio D.;Salto, César E.;
Anais da Sociedade Entomológica do Brasil , 1998, DOI: 10.1590/S0301-80591998000300004
Abstract: eriopis connexa (germar) is an important aphidophagous coccinelid, widely distributed in several south american countries. the influence of different feeding and temperature conditions on biological features of the immature and adult stages, were studied. cohorts of cocinelids larvae were reared on the combinations of four constant temperatures (9, 15, 19 and 27oc) and six diets based on acyrthosiphon pisum harris and schizaphis graminum (rondani) aphid species with, respectively, four and two different initial numbers and increasing rates. tested temperatures above 15oc did not affect the number of eggs/cluster and their viability. incubation time varied from 2.5 days and a 92% of hatched eggs at 27oc, to 13 days with a 71% of viability at 15oc. at 9oc, neither oviposition nor births were observed, although development until adult stage could be achieved at four experimental temperatures. the combination of food supply and temperature affected both aphid ingestion and immature developmental times, but not adult sizes. the number of a. pisum and s. graminum consumed varied approximately from 57 to 256 and from 104 to 641, respectively. developmental times, from larval to adult stage, ranged from ca. 84 days at 9oc to ca. 12 days at 27oc. larger adult sizes were observed at 19oc. body weight of adults increased when they were offered greater numbers of aphids. pronotum widths and femur lengths were slightly influenced by prey species but these dimensions were independent on larvae ingestion of food.
Dise?o de planes de muestreo con niveles fijos de precisión del pulgón manchado de la alfalfa, Therioaphis trifolii Monell (Homoptera: Aphididae) en alfalfa (Medicago sativa L.)
Gyenge, Javier E.;Trumper, Eduardo V.;Edelstein, Julio D.;
Anais da Sociedade Entomológica do Brasil , 1999, DOI: 10.1590/S0301-80591999000400016
Abstract: the objective of this paper was to design sequential sampling plans for the spotted alfalfa aphid (therioaphis trifolii monell) with fixed precision level, for density estimation and decision making. the study of spatial pattern based on taylor's power law and iwao's regression, showed different degrees of clumping of t. trifolii populations in alfalfa crops, depending on the developmental stage of aphids. the sequential sampling plan for decision making was calculated using two economic thresholds based on the height of the crop. the sequential sampling models developed by kuno and by green, were used to calculate stop lines. green's model is recommended because taylor's power law's regression yielded higher determination coefficients than iwao's method.
Dynamic Precursors of Flares in Active Region NOAA 10486
M. B. Korsos,N. Gyenge,T. Baranyi,A. Ludmany
Physics , 2015, DOI: 10.1007/s12036-015-9329-x
Abstract: Four different methods are applied here to study the precursors of flare activity in the Active Region NOAA 10486. Two approaches track the temporal behaviour of suitably chosen features (one, the weighted horizontal gradient WGM, is generalised form the horizontal gradient of the magnetic field, GM; another is the sum of the horizontal gradient of the magnetic field, GS, for all sunspot pairs). WGM is a photospheric indicator that is a proxy measure of magnetic non-potentiality of a specific area of the active region, i.e. it captures the temporal variation of the weighted horizontal gradient of magnetic flux summed up for the region where opposite magnetic polarities are highly mixed. The third one, referred to as the separateness parameter, S(lf), considers the overall morphology. Further, GS and S(lf) are photospheric newly defined quick-look indicators of the polarity mix of the entire active region. The fourth method is tracking the temporal variation of small x-ray flares, their times of succession and their energies observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager instrument. All approaches yield specific pre-cursory signatures for the imminence of flares.
Nafion含量与阴离子吸附对于铂单原子层核壳结构催化剂制备的影响
杨莉君,Dustin Banham, Elod Gyenge,叶思宇
- , 2017,
Abstract: 本实验利用铜的欠电位沉积技术,在旋转圆盘电极上以碳负载的钯纳米颗粒为核,制备铂单原子层核壳结构催化剂. 电化学测试用于表征不同Nafion含量的添加对于核壳结构催化剂制备的影响. 实验证明,Nafion的存在会影响铜的欠电位沉积,铂与铜的置换反应,并决定最终制备的核壳结构催化剂的氧还原催化反应的活性. 当催化剂薄层中Nafion的含量低于5%的时候,添加Nafion不但可以帮助催化剂附着在旋转圆盘电极表面,而且可以保证制备的催化剂具有较好的氧还原反应催化活性. 在H2SO4溶液中,钯纳米颗粒的表面存在特殊的阴离子吸/脱附电化学信号峰,这些信号峰可以用来监测Nafion含量对于铂单原子层核壳结构催化剂制备的影响.
Carbon supported palladium (Pd) nanoparticles were used as a model core material for the synthesis of platinum (Pt) monolayer core-shell catalysts using rotating disk electrode method and a copper (Cu) under potential deposition technique. The impact of Nafion on the synthesis process was revealed by electrochemical testing with various Nafion contents. The existence of Nafion influenced the Cu under potential deposition, galvanic replacement and eventually the oxygen reduction reaction activity of the core-shell catalyst. However, as long as the Nafion content was less than 5 wt% in the test film, adding Nafion could help to bind catalyst onto the surface of electrode while maintaining promising catalytic activity. Unique anion adsorption/desorption peaks were observed on the surface of Pd in H2SO4 solution, which turned out to be a useful indicator to evaluate the impact of Nafion on the synthesis of the core-shell catalysts.
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