No abstract

The results of global model simulation of an atmospheric pressure pulsed-DC helium plasma jet propagated in humid air, compared to the results of fluid model, are presented in this paper. The primary tasks of presented simulation were determination of the density and the main production pathways of OH radicals. The calculation reveals that global model gives higher OH densities than fluid model, especially at higher electron temperatures. This overestimation is mainly caused by the intrinsic assumptions of the global model, which impose limitations on its application for modelling of very transient physical processes such are streamers or plasma bullets. The main OH production and loss processes are well recognized by global model, and additional mechanisms are involved with respect to the case of fluid modelling. According to the presented results, global model will give satisfactory assessment of OH density and overall chemical composition of modelled plasmas, if the air fraction, electron density and temperature are correctly determined.

The experiment should answer the question of whether respondents are changing their preferences under the influence of subliminally exposed images and imperative messages. We also examined whether picture or imperative message has a stronger influence on the subject's decision. The experiment involved 210 females, who were divided into four experimental and two control groups. The film with subliminal images and messages that were contrary to what subjects preferred was presented to experimental groups, and control groups watched the same film without any messages. The results show that subliminal exposure of the material has impact on changing preferences and it turned out that the image has a stronger effect then the imperative message.

A zero-dimensional global model is developed with an aim to study the influence of air and water vapor on an electron energy distribution function, electron density, and temperature as well as on the chemical composition of atmospheric pressure helium plasmas, with special focus on the main reactive oxygen and nitrogen species important for applications of low temperature plasmas. The main channels for the production and consumption of electrons and electron energy gain and loss are examined by a global model based on a parametric study with variations of the mole fractions of air and water vapor. The calculations are done for 100, 1000, and 10 000 ppm of air in plasma, and for each of these values, the content of water vapor is taken to be 100, 1000, 2000, …, to 10 000 ppm. The variations of the most important production and consumption processes for reactive oxygen and nitrogen species are analyzed in detail. According to the results presented in this paper, water vapor highly contributes to electronegativity of the plasma through pronounced attachment of electrons, which then leads to an increase in electron temperature. For high water vapor content, vibrational excitations of water molecules are one of the main electron energy loss processes, leading to a further effect on the plasma composition. Water decreases concentrations of atomic oxygen, nitrogen, and ozone, while there is an increase in nitrogen oxide, OH, H2O2, and HO2 concentrations. Cross-sectional data for electron scattering on ground and excited state neutrals are mainly taken from the Quantemol-DB database.

Deca sadašnjice odrastaju u vremenu dominacije digitalnih medijia, sa mnoštvom uređaja koji utiču na njihov doživljaj i praktikovanje čitanja i pisanja. Primetan je porast upotrebe pametnih telefona i tableta, kao i uređaja specijalizovanih za čitanje. Mediji ponekad opisuju ove uređaje kao suštinski loše, štetne po zdravlje, spominje se i negativni uticaj na učenje, čitanje i pisanje. Čitanje preko ekrana razlikuje se od čitanje štampane knjige utoliko što se ne udubljujemo i brzo prelećemo po ekranu, manje je "mentalnog mapiranja", a zbog pojave specifičnog zamora izbegava se zahtevnija literatura. Naročito se podcrtavaju negativni efekti upotrebe interneta koji potkrepljuje stalnu aktivnost, a ne istrajavanje i razmišljanje, što vodi u rastrojenost i slabljenje koncentracije. Ipak, Internet je omogućio da se poveže tekst, slika, zvuk i film i uz to čini tekstualne sadržaje dostupnim bez većih troškova. Mobilne platforme omogućavaju da svako ima "džepnu biblioteku" koja nadmašuje fondove mnogih "pravih" biblioteka. Mada, "džepna biblioteka" ima smisla samo za onoga ko voli da čita i ume da koristi knjigu. Stoga, moramo tragati za uspešnim načinima upotrebe interneta i materijala dostupnih na njemu tako što ćemo kod učenika razvijati: umerenost, odmerenost, uzdržanje, kritičnostumesto lakoverstva, radoznalost-umesto ljubopitstva i istraživački duhumesto dogmatizma Ključne reči: čitanje, saznajni procesi, nove tenologije, Internet

The present work compares cross section sets for electron scattering from ground state helium and ground state water molecule, which are available at LXCat Morgan database and the new Quantemol-DB. These cross section sets are used as an input for numerical solving of Boltzmann equation by using electron Boltzmann solver BOLSIG+, in order to obtain transport coefficients, electron energy distribution function and rate coefficients for electron impact scattering processes. The calculated quantities are compared to examine the quality and completeness of the cross section sets provided by Quantemol database for modeling low-temperature plasmas and interpretation of experimental results.