40 research outputs found
The Effects of Commercials on Children’s Perceptions of Gender Appropriate Toy Use
Sixty-two first and second grade students (28 boys, 34 girls) were exposed to one of three commercial videotapes in which either all-boys (traditional condition) or all-girls (nontraditional) were playing with a toy. Participants in the control condition were exposed to nontoy commercials. After exposure to one of the conditions participants performed a toy sort where they were asked if six toys, including the two manipulated toys, were “for boys, girls, or both boys and girls.” Participants in the nontraditional condition were more likely to report that the manipulated toys were for both boys and girls than were participants in the traditional condition, who were more likely to report that the manipulated toys were for boys. This effect was stronger for boys than for girls.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45638/1/11199_2005_Article_1195.pd
On the use of nanocellulose as reinforcement in polymer matrix composites
AbstractNanocellulose is often being regarded as the next generation renewable reinforcement for the production of high performance biocomposites. This feature article reviews the various nanocellulose reinforced polymer composites reported in literature and discusses the potential of nanocellulose as reinforcement for the production of renewable high performance polymer nanocomposites. The theoretical and experimentally determined tensile properties of nanocellulose are also reviewed. In addition to this, the reinforcing ability of BC and NFC is juxtaposed. In order to analyse the various cellulose-reinforced polymer nanocomposites reported in literature, Cox–Krenchel and rule-of-mixture models have been used to elucidate the potential of nanocellulose in composite applications. There may be potential for improvement since the tensile modulus and strength of most cellulose nanocomposites reported in literature scale linearly with the tensile modulus and strength of the cellulose nanopaper structures. Better dispersion of individual cellulose nanofibres in the polymer matrix may improve composite properties
Gender role orientation is associated with health-related quality of life differently among African-American, Hispanic, and White youth
PurposeThis study examined the association between gender role orientation (GRO) and health-related quality of life (HRQOL) in youth, and how this relationship may differ between males and females as well as among African-American, White, and Hispanic individuals. GRO has been reported to influence serious health outcomes including cancer, heart disease, mental illness, and mortality rates. However, few studies have examined the link between GRO and health outcomes for children, even though gender identity is formed in childhood.MethodsData were examined from 4824 participants in the Healthy Passages™ project, a population-based survey of fifth-grade children in three US metropolitan areas. Children reported their own HRQOL using the PedsQL and degree of female, male, and androgynous GRO using the Children's Sex Role Inventory.ResultsBased on structural equations analysis, male GRO was positively associated with HRQOL for all racial/ethnic groups, regardless of sex, whereas female GRO was associated with better HRQOL for Hispanic and White females and poorer HRQOL for Hispanic males. Androgynous GRO was associated with better HRQOL among Hispanic and White females, but not males nor African-Americans of either sex.ConclusionsRacial/ethnic differences emerged for female and androgynous, but not male, GROs. Hispanic males are the only group for which GRO (female) was associated with poorer HRQOL. Future research should find ways to help youth overcome negative effects on health from gender beliefs and behavior patterns with sensitivity to racial/ethnic membership
Examining the Science and Practice of Violence Risk Assessment with Female Adolescents.
Dynamic Nanocellulose Networks for Thermoset-like yet Recyclable Plastics with a High Melt Stiffness and Creep Resistance
Many polymers, including polyethylene, feature a relatively low melting point and hence must be cross-linked to make them viable for applications that demand a high stiffness and creep resistance at elevated temperatures. The resulting thermoset plastics cannot be recycled, and therefore alternative materials with a reconfigurable internal network structure are in high demand. Here, we establish that such a thermoset-like yet recyclable material can be realized through the addition of a nanocellulose reinforcing agent. A network consisting of cellulose nanocrystals, nano- or microfibrils imparts many of the characteristics that are usually achieved through chemical cross-linking. For instance, the addition of only 7.5 wt % of either nanocellulose material significantly enhances the melt stiffness of an otherwise molten ethylene-acrylate copolymer by at least 1 order of magnitude. At the same time, the nanocellulose network reduces the meltcreep elongation to less than 10%, whereas the neat molten matrix would rupture. At high shear rates, however, the molten composites do not display a significantly higher viscosity than the copolymer matrix, and therefore retain the processability of a thermoplastic material. Repeated re-extrusion at 140 \ub0C does not compromise the thermomechanical properties, which indicates a high degree of recyclability. The versatility of dynamic nanocellulose networks is illustrated by 3D printing of a cellulose composite, where the high melt stiffness improves the printability of the resin