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Contains fulltext : 126866.pdf (publisher's version ) (Closed access), The work of group care workers in residential youth care is often described as professional parenting. Pedagogical interventions of group care workers influence the quality of care for looked-after children. The aim of the current study was to observe the pedagogical interventions of group care workers within residential youth care and their associations with child behaviors. Group care worker interventions and child behaviors were videotaped during structured observations. Participants included 95 children (64 % boys, M (age) = 9.19) and 53 group care workers (74 % female, M (age) = 33.79 years). A coding system was developed to code pedagogical interventions and child behaviors. It showed that group care workers mainly used positive pedagogical interventions (warmth/support and positive control) and seldom used negative pedagogical interventions (permissiveness and negative control). Frustration and anger of children was associated with positive controlling interventions and permissiveness of group care workers. The hypothesis that child anxiety and nervousness is associated with warm and supportive interventions could not be confirmed. Pedagogical interventions should be part of education, training, and supervision of group care workers.

Item does not contain fulltext, Group care workers in residential youth care are considered important in influencing behavioral development of children. In spite of this, their role has largely been neglected in research on residential care. The aim of the current study was twofold. First, longitudinal changes in group care worker interventions and child behaviors were investigated separately. Second, bidirectional influences between group care worker interventions and child behaviors were investigated. Group care workers completed the Group care worker Intervention Checklist and Child Behavior Checklist for 128 children (66% boys, mean age 8.63 years) at the beginning of the treatment and at two measurement intervals that followed (6 and 12 months, respectively). Most results contradicted the predictions. There was no change in controlling and warm and supportive interventions by group care workers. Autonomy granting interventions increased during treatment. Second, there were no changes in externalizing and internalizing behaviors of children over time.Third, cross-lagged analyses revealed that higher levels of controlling interventions increased externalizing problems of children. In the opposite direction, higher levels of children's externalizing problems were associated with an increase in controlling interventions of group care workers. In addition, higher levels of children's internalizing problems were associated with lower subsequent levels of autonomy granting interventions. These significant longitudinal paths were found only for the first phase of treatment. This study emphasizes the potential of the role of group care workers in residential youth care. Residential institutions should be aware of the dynamics between group care workers and children. Training and ongoing supervision in effective responses to behavior problems can increase the effect of group care worker interventions on child behavioral changes.

Contains fulltext : 102692.pdf (publisher's version ) (Closed access), Background By interacting with children, group care workers shape daily living environments to influence treatment. Current literature provides little knowledge about the content of youth residential care. Objective In this study, a questionnaire called the Group care worker Intervention Checklist was developed. Method Group care workers completed the questionnaires for 212 children placed in youth residential care in the Netherlands. Results Factor analyses revealed three constructs: controlling, warmth/support, and autonomy granting. Reliability of these scales proved to be good. Controlling was associated with Externalizing Behavior Problems while both Warmth/Support and Autonomy Granting were associated with Internalizing Behavior Problems. Conclusions These findings imply that group care worker interventions can be reliably measured and are related to child problem behavior.

A new predictive computational method for classifying clathrate hydrate promoter molecules is presented, based on the interaction energies between potential promoters and the water networks of sII and sH clathrates. The motivation for this work is identifying promoters for storing hydrogen compactly in clathrate hydrates. As a first step towards achieving this goal, we have developed a general method aimed at distinguishing between molecules that form sII clathrate hydrates and molecules that can - together with a weakly interacting help gas - form sH clathrate hydrates. The new computational method calculates differences in estimated formation energies of the sII and the sH clathrate hydrate. Model interaction potentials have been used, including the electrostatic interactions with newly calculated partial charges for all the considered potential promoter molecules. The methodology can discriminate between the clathrate structure types (sII or sH) formed by each potential promoter with good selectivity, i.e., better than achieved with a simple van der Waals diameter criterion.

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Contains fulltext : 90608.pdf (publisher's version ) (Closed access), The role of acquaintanceship with the child on reports of child behaviour by different informants was examined within the framework of a general theory of personality judgment. Mothers of referred children and group-care workers rated videotaped behaviour samples of a well known and an unknown child in the clinic. Independent observers also rated the videotapes. In line with the acquaintanceship hypothesis, mothers were found to perceive more behaviour problems than independent observers when rating well known children but not unknown children. Contrary to the acquaintanceship hypothesis, however, the group-care workers in our study reported more behaviour problems than the other informants regardless of their acquaintance with the children. The clinical and methodological implications of these findings are discussed.

Molecular dynamics simulations of hydrogen-containing type-sll clathrate hydrate slabs have been performed. A range of water-water interaction potentials were tested. Three potentials that yield water ice melting points close to 273 K gave very different

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RU Radboud Universiteit Nijmegen, 23 februari 2006, Promotores : Veerman, J.W., Bruyn, E.E.J. De, Contains fulltext : 55482.pdf (publisher's version ) (Open Access), 0ntbrkt

Contains fulltext : 54742.pdf (publisher's version ) (Open Access)

The enthalpies of dehydrogenation of the potential hydrogen storage material LiAlH4 and its deuterated counterpart, LiAlD4, have been calculated using density functional theory at the generalised gradient approximation level and harmonic phonon analysis.

The quasiharmonic approximation has been applied to the potential hydrogen storage material LiBH4 and its decomposition products. Whereas the lattice constants that minimize the DFT potential energy give good agreement with the experimentally observed values, minimizing the quasiharmonic free energy with respect to the lattice constants results in a significant overestimation. The enthalpy of dehydrogenation of LiBH4, including vibrational effects, is calculated to be 59±1 kJ mol H2 at 0 K, or 62.5±1.1 kJ mol H2 at 298 K.

Contains fulltext : 54617.pdf (publisher's version ) (Closed access), The present study compared ratings of a standardized sample of child behavior problems across informants and examined the effects of informant personality traits on child behavior ratings by mothers, teachers, and group-care workers. Participants were 55 clinic-referred children, aged 6–12 years. All informants watched and rated the same 17-min videotaped behavior sample of a familiar target child. Independent trained observers rated the same videotapes to provide criterion ratings. Informants personality traits were assessed using the NEO Five Factor Personality Inventory. Results showed that mothers reported fewer behavior problems than did the professionals, that the informants who were familiar with the child reported more behavior problems than did the independent observers, and that higher levels of informant neuroticism were related to higher ratings of child behavior problems in the case of the professionals, but not in the case of the mothers. In addition, group-care workers who were less extraverted and open were likely to report more child behavior problems than group-care workers with normal levels of extraversion and openness. Finally, no relations were found between agreeableness or conscientiousness and ratings of child behavior. Findings suggest that professionals who work with children are not immune to distortions based on their own personality.

We report density functional theory calculations on the energy of LiBH 4, relative to solid B and LiH and gaseous H2. The calculated energy is -71.3 (-76.1) kJ/mol H2 which can be approximately corrected for zero-point energy to give an enthalpy of -52 (-57) kJ/mol H2 at the PW91 (LDA) level, smaller than but similar to the experimental value of -68.9 kJ/mol H2. Calculations on four different LiBH4 phases indicate that alternative phases are not accessible at low temperatures without applying high pressures. These results indicate that complete decomposition to H2, B and LiH is not an attractive means of obtaining a reversible hydrogen storage system based on LiBH4.

We present the application of orbital-free density functional theory (OF-DFT) to NaAlH 4, a potential hydrogen storage material, and related systems. Although the simple Al and NaH structures are reproduced reasonably well by OF-DFT, the approach fails for the more complex NaAlH 4 structure. Calculations on AlH 3 show that the failure to describe the Al-H interaction is related to the kinetic energy functionals used rather than the local pseudopotentials which are required within the OF-DFT approach. Thus, systems such as NaAlh 4 present a challenge which awaits the development of more reliable orbital-free kinetic energy functionals.