The effect of calcium zirconate modifications on the microstructure and functional properties of sodium niobate thin films prepared by chemical solution deposition

Sodium niobate thin films doped with manganese (NN), and NN films modified with 5 or 10 mol % calcium zirconate (CZ) on platinized silicon substrates were prepared by chemical solution deposition. The 250-nm-thick films crystallize in a perovskite phase with fine, equiaxed grains. The NN films exhibit well-shaped ferroelectric loops with a remanent polarization and coercive field of ～10 μC/cm² and ～100 kV/cm, respectively. The modification with CZ strongly influences the ferroelectric response of the films: the remanent polarization progressively decreases to around 2.5 μC/cm². The absence of an anti-ferroelectric response, which has previously been confirmed in bulk NN-CZ ceramics, is attributed to the nanoscale microstructure and residual thermal stresses. All the studied films exhibit a piezoelectric response with the highest piezoelectric d₃₃ coefficient of 35 pm/V at 300 kV/cm bias field for the NN modified films with 5 mol % CZ, making them candidates for lead-free piezoelectric thin-film applications.     

Reducing the negative effects of stress in teams through cross-training: A job demands-resources model.

The purpose of this study was to utilize the job demands-resources model to examine the direct and interactive effects of job demands and cross-training on cognitive, behavioral, and affective outcomes in teams. Results from 54 teams indicated that an increase in job demands reduced mental model accuracy and information allocation and increased tension among team members. Cross-training, on the other hand, increased mental model accuracy and decreased tension among team members. More importantly, the direct effects of cross-training were qualified by the interaction. When job demands were high, cross-trained teams evidenced higher mental model accuracy, more information allocation, and less tension than teams that were not cross-trained. Cross-training was less influential when job demands were low, indicating that cross-training acted as a resource to buffer the negative impact of job demands in teams. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Thick as thieves: The effects of ethical orientation and psychological safety on unethical team behavior.

The purpose of this study was to uncover compositional and emergent influences on unethical behavior by teams. Results from 126 teams indicated that the presence of a formalistic orientation within the team was negatively related to collective unethical decisions. Conversely, the presence of a utilitarian orientation within the team was positively related to both unethical decisions and behaviors. Results also indicated that the relationship between utilitarianism and unethical outcomes was moderated by the level of psychological safety within the team, such that teams with high levels of safety were more likely to engage in unethical behaviors. Implications are discussed, as well as potential directions for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Evaluation of the Possibilities of Using PLGA Co-Polymer and Its Composites with Carbon Fibers or Hydroxyapatite in the Bone Tissue Regeneration Process �C in Vitro and in Vivo Examinations

Synthetic polymers belonging to the aliphatic polyester group have become highly promising biomaterials for reconstructive medicine. The purpose of the present work is a biological evaluation of lactide-glycolide co-polymer (PLGA) and its composites with carbon fibers (PLGA+CF) or hydroxyapatite (PLGA+HA). The cytotoxicity of the evaluated materials towards hFOB 1.19 human osteoblast-like cells was assessed. Moreover, during the one-year contact of the assessed materials with living osseous tissue, the progress of bone formation was analyzed and the accompanying process of the materials’ degradation was evaluated. The materials under evaluation proved to be biocompatible.     

Team learning: Collectively connecting the dots.

This article tests the degree to which personal and situational variables impact the acquisition of knowledge and skill within interactive project teams. On the basis of the literature regarding attentional capacity, constructive controversy, and truth-supported wins, the authors examined the effects of cognitive ability, workload distribution, Agreeableness, Openness to Experience, and structure on team learning. Results from 109 four-person project teams working on an interdependent command and control simulator indicated that teams learned more when composed of individuals who were high in cognitive ability and when the workload was distributed evenly. Conversely, team learning was negatively affected when teams were composed of individuals who were high in Agreeableness. Finally, teams using a paired structure learned more than teams structured either functionally or divisionally. Theoretical and practical implications are discussed, as well as possible limitations and directions for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Backing up behaviors in teams: The role of personality and legitimacy of need.

In this article, the authors developed several hypotheses regarding both the main and interactive effects of 2 types of team inputs on backing up behaviors in teams: (a) team composition characteristics in terms of the personality of the members of the team and (b) team task characteristics in terms of the extent to which the nature of the task is one that legitimately calls for some members of the team to back up other members of the team. Results from a study of 71 4-person teams performing a computerized tactical decision-making task suggest that the legitimacy of the need for back up has an important main effect on the extent to which team members provide assistance to and receive assistance from each other. In addition, the legitimacy of the need for back up also has important interactive effects with both the personality of the back up recipient and the personality of the back up providers on backing up behaviors in teams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinetics of particle nucleation and growth in the emulsion polymerization of acrylic monomers

The rates of particle formation and growth during the earliest stages of the emulsion polymerization of several acrylic monomers have been studied as a function of surfactant concentration by means of the time-dependence of light scattering from the reaction mixtures. Investigated were methyl methacrylate, and methyl, ethyl and butyl acrylates at concentrations of SDS surfactant from 0 to several times the CMC. Under continuous photoinitiation the Rayleigh scattering intensities rose rapidly with slopes that increased with decreasing SDS concentration. The more water-soluble the monomer, the more slowly was the rate of increase in scattering intensity. Computer modeling, using HUFT theory, could be used to obtain values for the various parameters involved for MMA. The Fuchs stability factor, W, was found to be 1 for [SDS] = 0 and infinity for [SDS] = CMC or grester. The partition coefficient for J-mer oligomers between the aqueous and organic phases must rise exponentially with J. Electrostatic effects on radical capture by particles are considered to be negligible, but very important as they affect coagulation kinetics.