Calculation of the magnetic field penetration depth for high-Tc cuprate superconductors based on the Interlayer Pair Tunneling model /

In this work, the magnetic field penetration depth for high-Tc cuprate superconductors is calculated using a recent Interlayer Pair Tunneling (ILPT) model proposed by Chakravarty, Sudb0, Anderson, and Strong [1] to explain high temperature superconductivity. This model involves a "hopping" of Cooper pairs between layers of the unit cell which acts to amplify the pairing mechanism within the planes themselves. Recent work has shown that this model can account reasonably well for the isotope effect and the dependence of Tc on nonmagnetic in-plane impurities [2] , as well as the Knight shift curves [3] and the presence of a magnetic peak in the neutron scattering intensity [4]. In the latter case, Yin et al. emphasize that the pair tunneling must be the dominant pairing mechanism in the high-Tc cuprates in order to capture the features found in experiments. The goal of this work is to determine whether or not the ILPT model can account for the experimental observations of the magnetic field penetration depth in YBa2Cu307_a7. Calculations are performed in the weak and strong coupling limits, and the efi"ects of both small and large strengths of interlayer pair tunneling are investigated. Furthermore, as a follow up to the penetration depth calculations, both the neutron scattering intensity and the Knight shift are calculated within the ILPT formalism. The aim is to determine if the ILPT model can yield results consistent with experiments performed for these properties. The results for all three thermodynamic properties considered are not consistent with the notion that the interlayer pair tunneling must be the dominate pairing mechanism in these high-Tc cuprate superconductors. Instead, it is found that reasonable agreement with experiments is obtained for small strengths of pair tunneling, and that large pair tunneling yields results which do not resemble those of the experiments.

Families of the traumatically brian-injured : a case study approach to perceptions of quality of service, degree of satisfaction, and family needs /

The purpose of this qualitative research study was to foster an understanding of the rehabilitation counselling practice offamilies of the brain-injured. Specifically, the study explores the perceptions of stakeholders in regards to the degree of satisfaction with the quality of service received. Questionnaires were administered, and semi-structured, openended interviews were conducted, with six participating families (n=8). Preliminary data were collected via two instruments: (i) the Family Participant Questionnaire, consisting of participants' sample characteristics, information pertaining to the history of the family, details of the injury, and information relating to the type, use, and need offamily services utilized; and (ii) the Community Integration Questionnaire, a measurement of the degree of social displacementllevel of community integration of the injured family member. Utilizing the procedural steps outlined by Colaizzi's (1978) method of protocol analysis, recommendations for a future program based on related and current family needs are discussed in detail. Substantiating and supporting information are offered to rehabilitation practitioners, educational planners, and policymakers alike, concerning the degree of satisfaction with rehabilitative service, and the means of improving upon the overall quality of health care to families of the brain-injured. Implications for clinical practice and research are also raised for discussion.

Parental goals among Italian-Canadian and Anglo-Canadian families : their connection to socialization practices and the quality of parent-young adult relationship /

Parenting goals are the behavioral, cognitive, and affective outcomes that parents implicitly or explicitly strive to achieve during specific interactions with their children. In the present study, intergenerational parenting practices and goals in Italian-Canadian and Anglo-Canadian families were examined. The association between parenting goals, parents' socialization practices, and the quality of relationship between parent and child were investigated. Participants included individuals ranging in age from 1 8-26 years and their mothers from Anglo-Canadian (n= 31) and Italian-Canadian families (n= 50). The young adults and their mothers were asked to imagine how their respective parents would have reacted to five hypothetical vignettes depicting difficult parent-child interactions. Young adults and their mothers were also asked to rate the importance of parenting goals within these parent-child situations. In addition, young adults assessed the perceived quality of their present relationships with each parent. Cultural differences were revealed such that Italian-Canadian parents endorsed more authoritarian parenting strategies and relationship-centered goals than Anglo-Canadian parents. However, Italian-Canadian and Anglo-Canadian parents were not found to differ on their endorsement of parent-centered goals. Italian-Canadian parents' who did use authoritarian strategies were found to have young-adult children who perceived their relationship with their parents as less satisfying, intimate, affectionate and having relatively high levels of conflict than parents who did not use authoritarian strategies. Anglo-Canadian parents' authoritative strategies were correlated with a better perceived relationship quality by young-adult children.