Variation in sex ratio, sexual dimorphism, and fitness components in populations of Mercurialis perennis L. (Euphorbiaceae) along the altitudinal gradient

Vrste roda Mercurialis su se pokazale kao atraktivan objekat za raznovrsna ekološka, genetička i istraţivanja u evolucionoj biologiji biljaka. Šumski prosinac, Mercurialis perennis L., je višegodišnja zeljasta anemofilna i dvodoma vrsta, karakteristična za primarna ili manje narušena šumska staništa. Analiza populacija ove vrste sa različitih nadmorskih visina pruţila je mogućnost da se na relativno malom geografskom prostoru istraţi uticaj velikog raspona variranja ekoloških faktora na morfološke karakteristike i reproduktivnu alokaciju (RA) kod pripadnika različitih polova, kao i na brojčani odnos polova u populaciji. Istraţivanje je obuhvatilo populacije sa 14 lokaliteta u Srbiji, koje su uzorkovane u periodu 2006–2009. Statistički značajno odstupanje od pretpostavljenog ravnoteţnog odnosa polova ustanovljeno je u 69,5% populacionih uzoraka. Broj uzoraka sa neravnoteţnim odnosom polova varirao je meĎu godinama, a u većini istraţenih populacija neravnoteţa je bila u korist muških biljaka. Neravnoteţa u korist muških biljaka ustanovljena je i u istraţivanjima na drugim populacijama ove vrste, a ovakav obrazac neravnoteţe polova se smatra uobičajenim za višegodišnje dvodome biljke. Indeks polnog dimorfizma je kod većine analiziranih osobina imao male do umerne vrednosti, dok su izrazito i dosledno dimorfne bile one osobine koje su direktno povezane sa reprodukcijom – broj cvetova i masa cvasti. Smer polnog dimorfizma razlikuje se kod ovih osobina. Muški pol produkuje više cvetova, što ukazuje na pojačanu intraseksualnu selekciju u muškom polu za veću produkciju polena. S druge strane, masa ţenskih cvasti je višestruko veća od mase muških cvasti, što se preslikava i u veću reproduktivnu alokaciju ţenskih jedinki. U ţenskom polu je detektovan i obrazac smanjenja ulaganja u reprodukciju sa povećanjem nadmorske visine na kojoj biljka raste. Analize polnog dimorfizma u visini biljke pokazale su da je u većini populacionih uzoraka muški pol viši, što se uklapa u pretpostavke hipoteze disperzije polena...The plant species of genus Mercurialis are very attractive object for various ecological, genetical and evolutionary researches. Dog’s mercury, Mercurialis perennis L., is a perennial anemophilous and dioecious herb, which usually grows in old and undisturbed forests. The analyses of populations of dog’s mercury from various altitudes gave us opportunity to investigate the effect of great environmental variation on morphological traits, reproductive allocation in different sexes, as well as on sex ratios in populations. This research included populations from 14 localities in Serbia sampled in 2006–2009. Statistically significant bias in sex ratio was found in 69.5% of population samples. Number of samples with biased sex ratio varied among years, and the majority of samples were male-biased. The male-biased populations of dog’s mercury were found elsewhere, and this pattern of bias is regarded to as the common one in dioecious perennials. Sexual dimorphism index for greater part of analysed traits had small to moderate values, while reproductive traits (number of flowers, mass of inflorescences) were markedly and consistently dimorphic. The range and direction of dimorphism differed in these reproductive traits. Males produced more flowers, and this information indicates pronounced intrasexual selection in males for greater pollen production. On the other hand, mass of female inflorescences was manifold bigger than mass of male inflorescences, and female reproductive allocation was bigger in a similar manner. In females, we also found pattern of decrease in reproductive allocation with the increase of altitude. The analyses of sexual dimorphism in plant size showed that males were the higher sex in majority of population samples. This is in agreement with pollen-dispersal hypothesis..

AC Impedance tracking of glassy carbon activation

Carbon materials, due to their physical and chemical properties, have found wide application in different electrochemical systems. They are often used as substrates for supercapacitors and different types of electrocatalysts. Upon activation, their electrochemical properties are improved. Glassy carbon can be successfully used as a model for studying the process of carbon activation. In this work, the activation of glassy carbon by electrochemical oxidation in sulfuric acid was investigated using cyclic voltammetry, electrochemical impedance spectroscopy and atomic force microscopy. Glassy carbon was oxidized during the same time at 5 different potentials. Cyclic voltammetry shows that the higher the potential the larger the increase in double layer capacitance is. Impedance measurements confirmed significant changes in capacitive response of activated glassy carbon in comparison to unoxidized state. AFM examination of treated GC surfaces revealed morphological changes and increase in roughness upon oxidation. If combined, the results of these studies show that the activation of glassy carbon proceeds through three stages: oxidation of active site, growing of graphite oxide layer and mechanical destruction of the surface.Belgrade, Serbia, June 6-10, 2010Related to the published paper in the Proceedings of the Second Regional Symposium on Electrochemistry South-East Europe, [http://cer.ihtm.bg.ac.rs/handle/123456789/3541

AC Impedance tracking of glassy carbon activation

Carbon materials, due to their physical and chemical properties, have found wide application in different electrochemical systems. They are often used as substrates for supercapacitors and different types of electrocatalysts. Upon activation, their electrochemical properties are improved. Glassy carbon can be successfully used as a model for studying the process of carbon activation. In this work, the activation of glassy carbon by electrochemical oxidation in sulfuric acid was investigated using cyclic voltammetry, electrochemical impedance spectroscopy and atomic force microscopy. Glassy carbon was oxidized during the same time at 5 different potentials. Cyclic voltammetry shows that the higher the potential the larger the increase in double layer capacitance is. Impedance measurements confirmed significant changes in capacitive response of activated glassy carbon in comparison to unoxidized state. AFM examination of treated GC surfaces revealed morphological changes and increase in roughness upon oxidation. If combined, the results of these studies show that the activation of glassy carbon proceeds through three stages: oxidation of active site, growing of graphite oxide layer and mechanical destruction of the surface.Belgrade, Serbia, June 6-10, 2010Related to the published paper in the Proceedings of the Second Regional Symposium on Electrochemistry South-East Europe, [http://cer.ihtm.bg.ac.rs/handle/123456789/3541

Application of different turbulence models for improving construction of small-scale boiler fired by solid fuel

Due to the rapid progress in computer hardware and software, CFD became a powerful and effective tool for implementation turbulence modeling in defined combustion mathematical models in the complex boiler geometries. In this paper the commercial CFD package, ANSYS FLUENT was used to model fluid flow through the boiler, in order to define velocity field and predict pressure drop. Mathematical modeling was carried out with application of Standard, RNG, and Realizable k-epsilon turbulence model using the constants presented in literature. Three boilers geometry were examined with application of three different turbulence models with variants, which means consideration of 7 turbulence model arrangements in FLUENT. The obtained model results are presented and compared with data collected from experimental tests. All experimental tests were performed according to procedures defined in the standard SRPS EN 303-5 and obtained results are presented in this paper for all three examined geometries. This approach was used for improving construction of boiler fired by solid fuel with heat output up to 35 kW and for selection of the most convenient construction

Discrete-time system conditional optimisation in the parameter space via the full transfer function matrix

Dynamic systems operate under the simultaneous influence of both the initial conditions and the input vector. There is neither physical nor mathematical justification for ignoring the initial conditions, e.g., in the control optimisation. This paper gives a response to the following question: Is a set of controller parameters which is optimal for the operation of a control system under zero initial conditions also optimal for its operation under non-zero initial conditions? The paper presents a new approach to the design of a classical proportional-differencesum (PDS) controller for a plant in a closed loop control system. The system relative stability with respect to a desired damping coefficient is accomplished. The minimal value of the performance index in the form of the sum of squared errors is the optimality criterion. Unlike the classical approach, the output error used in the performance index is influenced by all actions performed on the system at the same time

Chloride and fluoride contents in flue gas during domestic lignite coals combustion as a parameter in the design of flue gas desulphurisation plant

Od nedavno polje istraživanja sagorevanja uglja obuhvata i istraživanje nečistoća, posebno halogenih elemenata (F, Cl, I i At). Emisije hlorida i fluorida iz procesa sagorevanja zavise od sadržaja i oblika ovih elemenata u uglju, procesa sagorevanja i opreme za smanjenje emisija. Ispitivanje sadržaja hlorida i fluorida u uglju i dimnom gasu je posebno značajno pri projektovanju postrojenja za odsumporavanje dimnog gasa, sastavnog dela modernih termoelektrana, koje obezbeđuje ispunjenje propisanih zahteva u pogledu emisije _O2. U okviru sistema za odsumporavanje dimnog gasa, prisustvo HCl može dovesti do povećanja potrošnje sorbenta, a HCl i HF imaju uticaj na preradu otpadnih voda. U ovom radu su prikazani dobijeni rezultati sadržaja hlora i fluora u domaćim lignitima i njihova koncentracija u dimnom gasu. Cilj istraživanja je bilo utvrđivanje referentnih koncentracija Cl i F u dimnom gasu koje će biti korišćene pri projektovanju postrojenja za odsumporavanje dimnog gasa. PR Projekat Ministarstva nauke Republike Srbije, br. III 42010.Recently, research in the field of coal combustion include impurities, specifically halogen elements (F, Cl, Br, I and At). Emission of chlorides and fluorides from the combustion depends on content and forms of these elements in coal, combustion process and emission reduction equipment. Examination of chlorides and fluorides content in coal and in flue gas is particularly important for design of flue gas desulphurisation plant, the integral part of the modern power plants which ensure meeting the requirements of SO2 emission regulations. In flue gas desulphurisation facilities, the presence of HCl may increase sorbent consumption and HCl and HF have the influence on wastewater treatment. This paper presents the results of chlorine and fluorine contents in domestic lignites and their concentration in flue gas. The aim of investigation was to determine the reference Cl and F concentrations in flue gas that would be used in the design of flue gas desulphurization plant

Patomorfološke promene i distribucija virusnog antigena kod ptica inficiranih patogenim sojem H5N1 virusa avijarne influence

The aim of this study was to determine pathomorphological lesions in the organs of birds infected with H5N1 avian influenza virus, presence and distribution of the viral antigen in tissue samples and the degree of their correlation. Examination was conducted on the carcasses of seven mute swans (Cygnus olor) and one domestic rooster (Gallus gallus domesticus). After necropsy, trachea, lungs, liver, spleen, pancreas, kidney and intestine tissues were sampled for histopathology and immunohistochemical examination. LSAB method and H5N1 avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most frequent gross lesions were hemorrhages and necroses of the pancreas. Major histological lesions were multifocal necroses in the pancreas, liver and spleen, non purulent encephalitis, with neuronal dystrophy and neuronophagia. Viral nucleoprotein was immunohistochemically proven in the pancreas, brain, liver, lungs, and in one swan in the kidney. A high correlation between pathomorphological lesions and distribution of the viral antigen was determined.Cilj ovog ispitivanja je bio utvrđivanje patomorfoloških promena na organima ptica inficiranih H5N1 virusom avijarne influence, imunohistohemijsko utvrđivanje prisustva i distribucije virusnog antigena u parafinskim isečcima uzoraka njihovih organa, kao i utvrđivanje stepena njihove korelacije. Ispitivanje je izvršeno na organima sedam labudova grbaca (Cygnus olor) i jednog petla (Gallus gallus domesticus). Nakon izvršene obdukcije i makroskopskog pregleda svih organskih sistema, izvršeno je uzorkovanje tkiva mozga, traheje, pluća, jetre, slezine, pankreasa, bubrega i creva za patohistološka i imunohistohemijska ispitivanja. Korišćena je LSAB imunohistohemijska metoda sa poliklonskim antitelima na nukleoprotein virusa avijarne influence podtipa H5N1. Dominantne promene utvrđene makrokopskim pregledom bile su krvavljenja i nekroze pankreasa. Histološkim pregledom su ustanovljene multifokalne nekroze pankreasa, jetre i slezine, a u velikom mozgu promene u tipu negnojnog encefalitisa, praćene distrofijom i nekrozom nervnih ćelija i pojavom neuronofagije. Virusni nukleoprotein je imunohistohemijski dokazan u pankreasu, mozgu, jetri, plućima, slezini, a kod jednog labuda i u bubrezima. Utvrđen je visok stepen korelacije između ustanovljenih patomorfoloških promena i distribucije virusnog antigena

NOVI INSTITUTI U NEMAČKOM STEČAJNOM PRAVU

Germany was one of the first EU members to harmonize its legislation with the provisions of the European Union Directive no. 1023/2019 on preventive restructuring frameworks. The Law on Stabilization and Restructuring of Enterprises (StaRUG) introduced several new institutes through a modular approach with the aim of preventing insolvency. It entered into force on 1st January 2021 and provided a pre-bankruptcy procedure, as a novelty, rearranged procedure of personal administration of debtors in bankruptcy and the mediation procedure in restructuring. This enables business entities to timely determine the existence of circumstances that may jeopardize business, but also established the obligation to act appropriately in a timely manner. The instruments of the new legal framework are the adoption of the restructuring plan in court proceedings, the court examination of the contents of the restructuring plan, the court moratorium on executions and the court confirmation of the restructuring plan, as well as adoption of the plan in the mediation procedure. The aforementioned reform further strengthened the principles of consensualism in insolvency law. Also, this law represents a good model for other EU states and for candidate states in the process of harmonization of legislation with EU regulations as well. The aim of this paper is to provide an insight into the new institutes in German legislation, to analyze them and to give a critical review of their application in practice.Nemačka je među prvima uskladila svoje zakonodavstvo sa odredbama Direktive Evropske unije br. 1023/2019 o okvirima za preventivno restrukturiranje. Zakonom o stabilizaciji i restrukturiranju preduzeća je modularnim pristupom uvedeno nekoliko novih instituta s ciljem prevencije nesposobnosti plaćanja. Time je omogućeno privrednim subjektima da pravovremeno utvrde okolnosti koje mogu ugroziti poslovanje. Instrumenti novog pravnog okvira su usvajanje plana restrukturiranja u sudskom postupku, sudsko ispitivanje plana restrukturiranja, sudski moratorijum na izvršenja i sudsko potvrđivanje plana restrukturiranja, kao i postupak medijacije. Navedenom reformom dodatno je pojačano načelo konsensualizma u stečajnom pravu. Takođe, ovaj zakon je dobar model za druge države. Cilj ovog rada je da pruži uvid u nove institute u nemačkom zakonodavstvu, da ih analizira i da dâ kritički osvrt na njihovu primenu u praksi

Multicomponent Modelling Kinetics and Simultaneous Thermal Analysis of Apricot Kernel Shell Pyrolysis

Apricot kernel shells are naturally available source of biomass with potential for conversion to clean energy through a thermo-chemical process such as pyrolysis. To facilitate further process development, an advanced mathematical model which represents the process kinetics is developed and validated on the thermal decomposition studies using simultaneous thermal analysis, over a temperature range of 30-900 °C, at four heating rates of 5, 10, 15 and 20 °C min−1, under argon atmosphere. Model-free analysis and numerically developed methods were utilized for determination of effective activation energies, pre-exponential factors and the fractional contribution. A novel approach is introduced in order to determine actual pseudo-components of studied biomass that are included in its composition. The comparative study of the obtained kinetic results was also presented. The results obtained strongly indicated that the pseudo-component reaction modelling method could be employed to predict the experimental devolatilization rate and biomass composition with a high likelihood of success

RESPONSES OF THE IONOSPHERIC D-REGION TO PERIODIC AND TRANSIENT VARIATIONS OF THE IONIZING SOLAR Lyα RADIATION

Solar radiation has the most important role in periodical variation of terrestrial atmospheric properties. Under unperturbed ionospheric conditions, the solar Lyα line has a dominant influence on ionization processes in the lowest ionospheric layer, the so called D-region. In this paper, we present periodical and transient variations in influences of the Lyα radiation on this ionospheric layer. In the case of periodical lower ionospheric changes we consider diurnal, seasonal and solar cycle variations and show analysis of acoustic and gravity waves induced by solar terminator. Influences of solar flares and eclipses on this atmospheric layer are analyzed as examples of sudden ionospheric disturbances. For decades, Very Low Frequency radio signals (3 – 30 kHz) are successfully used as a tool for monitoring of changes in the lower ionosphere, based on radio wave propagation through Earth-ionosphere waveguide along given trajectories and registration of their physical parameters (amplitude and phase delay). For the analysis conducted in this paper, we used records of the VLF DHO signal, emitted on 23.4 kHz frequency from transmitter in Germany and received in Serbia