Themes and Gender Portrayals in Saturday Morning Children\u27s Television Advertisements

The purpose of this study was to examine the content of advertisements directed toward boys and girls ages six to twelve. Gender portrayals, settings, activities, themes and types of advertisements were variables analyzed in the sample. Data collected from the advertisements were taken from a random sample of four Saturdays of children’s programming between 6 a.m. and 12 p.m. CBS, ABC, and FOX were the three networks and Nickelodeon was the cable channel used in the study. Out of 1079 advertisements observed in the sample, 220 were not repeated. Results revealed that the most frequent types of advertisements viewed sold food (54 percent) and toy products (44 percent). More advertisements directed toward girls contained inside settings and passive activities, compared to those directed toward boys, which contained more outside and fantasy settings and active activities. Dominant themes in boy advertisements were adventure and conflict, while many of the advertisements directed toward girls were humorous. Social and observational learning theories explain how and why children model characters in the advertisements they view. Because gender roles and behaviors are apparent in advertisements directed toward children, it is important to examine exactly what they are watching between their favorite programs

Towards perfect spin-filtering : a first-principles study

The aim of this thesis was to study theoretically spin-dependent transport in\ud layered structures containing transition metal itinerant ferromagnets, based upon a quantum-mechanical description of electronic transport as the most appropriate for an accurate description on an atomic scale

Ni(111)|Graphene|h-BN Junctions as Ideal Spin Injectors

Deposition of graphene on top of hexagonal boron nitride (h-BN) was very recently demonstrated while graphene is now routinely grown on Ni. Because the in-plane lattice constants of graphite, h-BN, graphite-like BC2N and of the close-packed surfaces of Co, Ni and Cu match almost perfectly, it should be possible to prepare ideal interfaces between these materials which are respectively, a semimetal, insulator, semiconductor, ferromagnetic and nonmagnetic metals. Using parameter-free energy minimization and electronic transport calculations, we show how h-BN can be combined with the perfect spin filtering property of Ni|graphite and Co|graphite interfaces to make perfect tunnel junctions or ideal spin injectors (SI) with any desired resistance-area product.Comment: 4 pages, 4 figures. Accepted for publication in Physical Review

Analysis of female handball players’ effort in different playing positions during official matches

The aim of the present study was to establish the physiological workload that female handball players are exposed to in different playing positions during official matches. The research included fifteen HC Krim Mercator female handball team players. During the 2009/10 season, six matches of the Women’s Regional Handball League were analysed. The results indicated that at the lowest monitored workload in the 50–59% range of maximum heart rate (HRmax) there were no statistically significant differences between groups of players in particular playing positions. Workload intervals of 60 to 69% and 70 to 79% HRmax showed statistically significant (p<.05) differences between goalkeepers and all the other groups of players; on average, goalkeepers spent more time in the low-effort zones than the other groups of players. Groups of goalkeepers (25min 44s±9min 40s) and backs (25min 36s±7min 24s) did not significantly differ with regard to the time players spent in the 80 to 89% HRmax interval. However, the previously mentioned two groups of players had significantly higher values (p<.05) in this interval than groups of pivots (19min 42s±7min 45s) and wings (15min 52s±8min 11s). In the highest-effort interval (90–100%), groups of wings (27min 28s±9min 20s) and pivots (35min 55s±12min 41s) reached significantly higher values (p<.05) than goalkeepers (4min 57s±4min 58s) and backs (19min 04s±9min 00s). Goalkeepers, in contrast, recorded significantly lower values than the other three groups of players. We can conclude that during the analysed matches pivots and wings showed the highest levels of effort, followed by backs. Due to markedly different physiological workloads, physical preparation for different playing positions should also be quite different. Coaches should use the results of this study in practice to make timely decisions on when to substitute players in different position in order to prevent possible drop in their playing efficiency

Analysis of female handball players’ effort in different playing positions during official matches

The aim of the present study was to establish the physiological workload that female handball players are exposed to in different playing positions during official matches. The research included fifteen HC Krim Mercator female handball team players. During the 2009/10 season, six matches of the Women’s Regional Handball League were analysed. The results indicated that at the lowest monitored workload in the 50–59% range of maximum heart rate (HRmax) there were no statistically significant differences between groups of players in particular playing positions. Workload intervals of 60 to 69% and 70 to 79% HRmax showed statistically significant (p<.05) differences between goalkeepers and all the other groups of players; on average, goalkeepers spent more time in the low-effort zones than the other groups of players. Groups of goalkeepers (25min 44s±9min 40s) and backs (25min 36s±7min 24s) did not significantly differ with regard to the time players spent in the 80 to 89% HRmax interval. However, the previously mentioned two groups of players had significantly higher values (p<.05) in this interval than groups of pivots (19min 42s±7min 45s) and wings (15min 52s±8min 11s). In the highest-effort interval (90–100%), groups of wings (27min 28s±9min 20s) and pivots (35min 55s±12min 41s) reached significantly higher values (p<.05) than goalkeepers (4min 57s±4min 58s) and backs (19min 04s±9min 00s). Goalkeepers, in contrast, recorded significantly lower values than the other three groups of players. We can conclude that during the analysed matches pivots and wings showed the highest levels of effort, followed by backs. Due to markedly different physiological workloads, physical preparation for different playing positions should also be quite different. Coaches should use the results of this study in practice to make timely decisions on when to substitute players in different position in order to prevent possible drop in their playing efficiency

Influence of Roughness and Disorder on Tunneling Magnetoresistance

A systematic, quantitative study of the effect of interface roughness and disorder on the magnetoresistance of FeCo$|$vacuum$|$FeCo magnetic tunnel junctions is presented based upon parameter-free electronic structure calculations. Surface roughness is found to have a very strong effect on the spin-polarized transport while that of disorder in the leads (leads consisting of a substitutional alloy) is weaker but still sufficient to suppress the huge tunneling magneto-resistance (TMR) predicted for ideal systems

Electronic structure and magnetic properties of the graphene/Fe/Ni(111) intercalation-like system

The electronic structure and magnetic properties of the graphene/Fe/Ni(111) system were investigated via combination of the density functional theory calculations and electron-spectroscopy methods. This system was prepared via intercalation of thin Fe layer (1 ML) underneath graphene on Ni(111) and its inert properties were verified by means of photoelectron spectroscopy. Intercalation of iron in the space between graphene and Ni(111) changes drastically the magnetic response from the graphene layer that is explained by the formation of the highly spin-polarized $3d_{z^2}$ quantum-well state in the thin iron layer.Comment: Manuscript and supplementary material

Theoretical prediction of perfect spin filtering at interfaces between close-packed surfaces of Ni or Co and graphite or graphene

The in-plane lattice constants of close-packed planes of fcc and hcp Ni and Co match that of graphite almost perfectly so that they share a common two dimensional reciprocal space. Their electronic structures are such that they overlap in this reciprocal space for one spin direction only allowing us to predict perfect spin filtering for interfaces between graphite and (111) fcc or (0001) hcp Ni or Co. First-principles calculations of the scattering matrix show that the spin filtering is quite insensitive to amounts of interface roughness and disorder which drastically influence the spin-filtering properties of conventional magnetic tunnel junctions or interfaces between transition metals and semiconductors. When a single graphene sheet is adsorbed on these open $d$-shell transition metal surfaces, its characteristic electronic structure, with topological singularities at the K points in the two dimensional Brillouin zone, is destroyed by the chemical bonding. Because graphene bonds only weakly to Cu which has no states at the Fermi energy at the K point for either spin, the electronic structure of graphene can be restored by dusting Ni or Co with one or a few monolayers of Cu while still preserving the ideal spin injection property.Comment: 12 pages, 11 figure

Graphite and graphene as perfect spin filters

Based upon the observations (i) that their in-plane lattice constants match almost perfectly and (ii) that their electronic structures overlap in reciprocal space for one spin direction only, we predict perfect spin filtering for interfaces between graphite and (111) fcc or (0001) hcp Ni or Co. The spin filtering is quite insensitive to roughness and disorder. The formation of a chemical bond between graphite and the open $d$-shell transition metals that might complicate or even prevent spin injection into a single graphene sheet can be simply prevented by dusting Ni or Co with one or a few monolayers of Cu while still preserving the ideal spin injection property

Doping graphene with metal contacts

Making devices with graphene necessarily involves making contacts with metals. We use density functional theory to study how graphene is doped by adsorption on metal substrates and find that weak bonding on Al, Ag, Cu, Au and Pt, while preserving its unique electronic structure, can still shift the Fermi level with respect to the conical point by $\sim 0.5$ eV. At equilibrium separations, the crossover from $p$-type to $n$-type doping occurs for a metal work function of $\sim 5.4$ eV, a value much larger than the graphene work function of 4.5 eV. The numerical results for the Fermi level shift in graphene are described very well by a simple analytical model which characterizes the metal solely in terms of its work function, greatly extending their applicability.Comment: 4 pages, 5 figure