On the formulation and the calculation of the harmonic contributions to the Debye-Waller factor in metals (sodium)

The algebraic expressions for the anharmonic contributions to the Debye-Waller factor up to 0(A ) and 0 L% ) £ where ^ is the scattering wave-vector] have been derived in a form suitable for cubic metals with small ion cores where the interatomic potential extends to many neighbours. This has been achieved in terms of various wave-vector dependent tensors, following the work of Shukla and Taylor (1974) on the cubic anharmonic Helmholtz free energy. The contribution to the various wave-vector dependent tensors from the coulomb and the electron-ion terms in the interatomic metallic potential has been obtained by the Ewald procedure. All the restricted multiple whole B r i l l o u i n zone (B.Z.) sums are reduced to single whole B.Z. sums by using the plane wave representation of the delta function. These single whole B.Z. sums are further reduced to the •%?? portion of the B.Z. following Shukla and Wilk (1974) and Shukla and Taylor (1974). Numerical calculations have been performed for sodium where the Born-Mayer term in the interatomic potential has been neglected because i t is small £ Vosko (1964)3 • *n o^er to compare our calculated results with the experimental results of Dawton (1937), we have also calculated the r a t io of the intensities at different temperatures for the lowest five reflections (110), (200), (220), (310) and (400) . Our calculated quasi-harmonic results agree reasonably well with the experimental results at temperatures (T) of the order of the Debye temperature ( 0 ). For T » © ^ 9 our calculated anharmonic results are found to be in good agreement with the experimental results.The anomalous terms in the Debye-Waller factor are found not to be negligible for certain reflections even for T ^ ©^ . At temperature T yy Op 9 where the temperature is of the order of the melting temperature (Xm) » "the anomalous terms are found to be important almost for all the f i ve reflections.

A Basis for Understanding Volunteer Coach Retention in Youth Sports

Youth sport organizations depend on volunteers to coach the teams in the organization. The purpose of this quantitative study was to develop a further understanding of volunteer coach retention in youth sport. The data was collected through a quantitative questionnaire which used close-ended and Likert-scale questions. The questionnaire collected data on the modified Model of Volunteer Retention in Youth Sports, reasons to withdraw from coaching and human resource management. There were 126 surveys collected from members of the three largest youth sport associations in the town of Aylmer, Ontario. The study found that Person-Task fit was the best predictor of volunteer coach retention as it significantly correlated to one’s intention to continue coaching (p< 0.01). Furthermore, additional reasons were found to explain withdrawal from coaching - if one’s child stops playing the sport or if coaching is too time consuming. The retention of volunteer coaches in youth sport organizations requires a multi-dimensional approach in understanding how to best retain volunteer coaches.

Chronic versus acute ingestion of sodium citrate: a randomized placebo controlled cross-over trial for swimming 200 metres in well-trained swimmers age 13-17

A double-blinded, placebo controlled, cross-over design was used to investigate sodium citrate dihydrate (Na-CIT) supplementation improve 200m swimming performance. Ten well-trained, male swimmers (14.9 ± 0.4y; 63.5 ± 4kg) performed four 200m time trials: acute (ACU) supplementation (0.5g/kg), acute placebo (PLC-A), chronic (CHR) (0.1g/kg for 3 days and 0.3g/kg on the 4th day pre-trial), and chronic placebo (PLC-C). Na-CIT was administered 120min pre-trial in solution with 500mL of flavored water; placebo was flavored water. Blood lactate, base excess (BE), bicarbonate, pH, and PCO2 were analyzed at basal, 100min post-ingestion, and 3min post-trial via finger prick. Time, lactate, and rate of perceived exertion were not different between trials. BE and bicarbonate were significantly higher for the ACU and CHR trials compared to placebo. “Responders” improved by 1.03% (P=0.043) and attained significantly higher post-trial lactate concentrations in the ACU versus PLC-A trials and compared to non-responders in the ACU and CHR trials.

“You Know What I Mean?”- Language and Cultural Retention in Luso-Canadian Mothers in the Greater Toronto Area

The Portuguese community is one of the largest diasporic groups in the Greater Toronto Area and the choice of retention and transmission of language and culture to Luso-Canadians is crucial to the development and sustainability of the community. The overall objective of this study is to learn about the factors that influence Luso-Canadian mothers’ inclination to teach Portuguese language and cultural retention to their children. To explore this topic I employed a qualitative research design that included in-depth interviews conducted in 2012 with six Luso-Canadian mothers. Three central arguments emerged from the findings. First, Luso-Canadian mothers interviewed posses a pronounced desire for their children to succeed academically, and to provide opportunities that their children that they did not have. Second, five of the mothers attempt to achieve this mothering objective partly by disconnecting from their Portuguese roots, and by disassociating their children from the Portuguese language and culture. Third, the disconnection they experience and enact is influenced by the divisions evident in the Portuguese community in the GTA that divides regions and hierarchically ranks dialects, and groups. I conclude that the children in these households inevitably bear the prospects of maintaining a vibrant Portuguese community in the GTA and I propose that actions by the community in ranking dialects influence mothers’ decisions about transmitting language and culture to their children.