255 resultados para psychological overview
Resumo:
The current eight published ISO standards associated with semiconductor photocatalysis are considered. These standards cover: (1) air purification (specifically, the removal of NO, acetaldehyde and toluene), (2) water purification (the photobleaching of methylene blue and oxidation of DMSO) (3) self-cleaning surfaces (the removal of oleic acid and subsequent change in water droplet contact angle), (4) photosterilisation (specifically probing the antibacterial action of semiconductor photocatalyst films) and (5) UV light sources for semiconductor photocatalytic ISO work. For each standard, the background is first considered, followed by a brief discussion of the standard particulars and concluding in a discussion of the pros and cons of the standard, with often recommendations for their improvement. Other possible standards for the future which would either compliment or enhance the current ones are discussed briefly.
Resumo:
In recent times the sociology of childhood has played an important role in challenging the dominance of Piagetian models of child development in shaping the way we think about children and childhood. What such work has successfully achieved is to increase our understanding of the socially constructed nature of childhood; the social competence and agency of children; and the diverse nature of children’s lives, reflecting the very different social contexts within which they are located. One of the problems that has tended to be associated with this work, however, is that in its critique of developmentalism it has tended simply to replace one orthodoxy (psychology) with another (sociology) rather than providing the opportunity to transcend this divide. The purpose of this paper is to demonstrate some of the potential ways in which the sociological/psychological divide might be transcended and the benefits of this for understanding, more fully, the ‘production’ of children’s schooling identities. In particular it shows how some of the key sociological insights to be found in the work of Bourdieu may be usefully extended by the work inspired by the developmental psychologist, Vygotsky. The key arguments are illustrated by reference to ethnographic data relating to the schooling experiences and identities of a group of 5-6 year old working class boys.
Resumo:
A series of numerical simulations based on a recurrence-free Vlasov kinetic model using kinetic phase point trajectories are presented. Electron-ion plasmas and three-component (electron-ion-dust) dusty or complex plasmas are considered, via independent simulations. Considering all plasma components modeled through a kinetic approach, the linear and nonlinear behavior of ion-acoustic excitations is investigated. Maxwellian and kappa-type (superthermal) distribution functions are assumed, as initial conditions, in separate simulations for the sake of comparison. The focus is on the parametric dependence of ion-acoustic waves on the electron-to-ion temperature ratio and on the dust concentration. © 2014 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.
Resumo:
Biofilms are communities of microbial cells that underpin diverse processes including sewage bioremediation, plant growth promotion, chronic infections and industrial biofouling. The cells resident in the biofilm are encased within a self-produced exopolymeric matrix that commonly comprises lipids, proteins that frequently exhibit amyloid-like properties, eDNA and exopolysaccharides. This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption. Critical to the development of novel strategies to control biofilm infections, or the capability to capitalize on the power of biofilm formation for industrial and biotechnological uses, is an in-depth knowledge of the biofilm matrix. This is with respect to the structure of the individual components, the nature of the interactions between the molecules and the three-dimensional spatial organization. We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community. We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars.
Resumo:
Electron–positron (e–p) plasmas are widely thought to be emitted, in the form of ultra-relativistic winds or collimated jets, by some of the most energetic or powerful objects in the Universe, such as black-holes, pulsars, and quasars. These phenomena represent an unmatched astrophysical laboratory to test physics at its limit and, given their immense distance from Earth (some even farther than several billion light years), they also provide a unique window on the very early stages of our Universe. However, due to such gigantic distances, their properties are only inferred from the indirect interpretation of their radiative signatures and from matching numerical models: their generation mechanism and dynamics still pose complicated enigmas to the scientific community. Small-scale reproductions in the laboratory would represent a fundamental step towards a deeper understanding of this exotic state of matter. Here we present recent experimental results concerning the laser-driven production of ultra-relativistic e–p beams. In particular, we focus on the possibility of generating beams that present charge neutrality and that allow for collective effects in their dynamics, necessary ingredients for the testing pair-plasma physics in the laboratory. A brief discussion of the analytical and numerical modelling of the dynamics of these plasmas is also presented in order to provide a summary of the novel plasma physics that can be accessed with these objects. Finally, general considerations on the scalability of laboratory plasmas up to astrophysical scenarios are given.
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This is a novel investigation of whether, and how, a single close supportive friendship may facilitate psychological resilience in socio-economically vulnerable British adolescents. A total of 409 adolescents (160 boys, 245 girls, four unknown), aged between 11 and 19 years, completed self-report measures of close friendship quality, psychological resilience, social support, and other resources. Findings revealed a significant positive association between perceived friendship quality and resilience. This relationship was facilitated through inter-related mechanisms of developing a constructive coping style (comprised of support-seeking and active coping), effort, a supportive friendship network, and reduced disengaged and externalising coping. While protective processes were encouragingly significantly present across genders, boys were more vulnerable to the deleterious effects of disengaged and externalizing coping than girls. We suggest that individual close friendships are an important potential protective mechanism accessible to most adolescents. We discuss implications of the resulting Adolescent Friendship and Resilience Model for resilience theories and integration into practice.
Resumo:
Evidence-based thermal care recommendations designed to minimize heat loss immediately at birth are readily available however, hypothermia still persists as a global challenge especially when caring for the most immature and smallest preterm infants. In this narrative overview we aim to provide the reader with a succinct summary of the causes and consequences of hypothermia, the extent of the problem (rates of hypothermia), principles of good thermal care, delivery room preventative measures, the research evidence underpinning existing interventions, current issues in practice, and the way forward. Due to the plethora of research literature available in this subject area, our article will focus primarily on evidence derived from systematic reviews and randomized or quasi-randomized controlled trials assessing the effectiveness of interventions to prevent hypothermia in the most vulnerable (preterm/low birth weight) infants where the intervention or combination of interventions is applied immediately at birth. © 2014.
Resumo:
Even though computational power used for structural analysis is ever increasing, there is still a fundamental need for testing in structural engineering, either for validation of complex numerical models or material behaviour. Many structural engineers/researchers are aware of cyclic and shake table test methods, but less so hybrid testing. Over the past 40 years, hybrid testing of engineering structures has developed from concept through to maturity to become a reliable and accurate dynamic testing technique. In particular, the application of hybrid testing as a seismic testing technique in recent years has increased notably. The hybrid test method provides users with some additional benefits that standard dynamic testing methods do not, and the method is much more cost effective in comparison to shake table testing. This paper aims to provide the reader with a basic understanding of the hybrid test method and its potential as a dynamic testing technique.
Resumo:
The practice of sustainable peace is a process that must be initiated, nourished and revised. The
“social energies” of conflict transformation – truth, mercy, justice, peace – offer a useful model to describe the transformative power of this practice. These social energies can be conceptualized as a combination of norms or values, on the one hand, and actions directed toward social reconstruction, on the other. As such, the social energies of conflict transformation are both the guideposts and the engine in the journey of practicing sustainable peace. This article begins by
linking psychological constructs of narrative/voice, empathy/altruism, individual/collective guilt, and security/fear with the social energies, highlighting the interdependence of processes and shifting the focus away from pathology toward an emphasis on harmony. An empirical application of how the four social energies contribute to the mobilization, maintenance and adaptations in on-going peace processes in post-war Guatemala is then presented. By analyzing the interaction among diverse actors and goals in the decade and a half since the signing of the 1996 Peace Accords, current theory is extended in two ways: a) differentiation between elite and grassroots initiatives, and b) specification and evaluation the impact of various efforts on episodic and structural violence. We conclude that although national and local processes have
had limited success, more integrated practices of truth, mercy, justice and peace are necessary if Guatemala is to make sustainable peace a reality. The findings from this case study have policy and practical implications for other countries facing protracted, violent conflict.