The effects of moisture, cation concentration, temperature, density and composition of soils on their electrical resistivity

The effects. of moisture, cation concentration, dens ity , temper~ t ure and grai n si ze on the electrical resistivity of so il s are examined using laboratory prepared soils. An i nexpen si ve method for preparing soils of different compositions was developed by mixing various size fractions i n the laboratory. Moisture and cation c oncentration are related to soil resistivity by powe r functions, whereas soil resistiv ity and temperature, density, Yo gravel, sand , sil t, and clay are related by exponential functions . A total of 1066 cases (8528 data) from all the experiments were used in a step-wise multiple linear r egression to determine the effect of each variable on soil resistivity. Six variables out of the eight variables studied account for 92.57/. of the total variance in so il resistivity with a correlation coefficient of 0.96. The other two variables (silt and gravel) did not increase the · variance. Moisture content was found to be - the most important Yo clay. variable- affecting s oil res istivi ty followed by These two variables account for 90.81Yo of the total variance in soil resistivity with a correlation ~oefficient ·.of 0 . 95. Based on these results an equation to ' ~~ed{ ct soil r esist ivi ty using moisture and Yo clay is developed . To t est the predicted equation, resistivity measurements were made on natural soils both in s i tu a nd i n the laboratory. The data show that field and laboratory measurements are comparable. The predicted regression line c losely coinciqes with resistivity data from area A and area B soils ~clayey and silty~clayey sands). Resistivity data and the predicted regression line in the case of c layey soils (clays> 40%) do not coincide, especially a t l ess than 15% moisture. The regression equation overestimates the resistivity of so i l s from area C and underestimates for area D soils. Laboratory prepared high clay soils give similar trends. The deviations are probably caused by heterogeneous distribution of mo i sture and difference in the type o f cl ays present in these soils.

Our future in geriatrics : an examination of the knowledge, attitudes and career choices of physical therapy students in Ontario : a pretest-posttest study /

There continues to be a shortage of health professionals interested in providing care for the older adult. Part of the problem seems to stem from the negative perceptions of geriatrics as a clinical speciality. This study examines the knowledge, attitudes and career decisions of physical therapy students in Ontario before and after an educational intervention. Surveys were conducted with 144 physical therapy students from five universities before and after their geriatrics course in order to measure their knowledge, attitudes and interest in working with older adults. The incoming class of physical therapy students (n = 1 86) acted as control subjects for the study. The Revised Palmore Facts On Aging Quiz measured the students' knowledge of aging (Miller & Dodder, 1980). The Revised Tuckman-Lorge (Axelrod & Eisdorfer, 1961) and the Kogan Old People Scales (Kogan, 1961) were used to examine attitude. An environmental scale was developed based on the work of Snape (1986) to measure the impact of the working conditions on the students' career choices. A 10-point Likert-type scale based on the work of Michlelutte & Diseker (1985) was modified and used to measure career interest in working with the elderly. On independent sample t-tests, positive attitudes were related to the demographic characteristic of gender; ethnicity was negatively related; and marital status was found to be unrelated to attitude (fi<.05). Having a relationship with an older adult and taking courses in gerontology were also found to be positively related to attitude (fi<.05). Results on a betweensubjects design which compared students before and after the course found that knowledge scores improved from pretest to posttest (fi<.05). In general, attitude scores improved from T1 to T2 on both measurement tools (b<.05). The environmental and vocational interest scales yielded statistically significant differences between the control and experimental groups during the intervention period (p<.05). The results of this research indicated that knowledge and attitudes improve after an educational intervention; however, there was little impact on the students' overall career decisions. Further research is indicated to examine the complex relationship between attitude and behaviour and its impact on students' career choices. In addition, the impact of geriatric clinical environment on students' attitudes and career decisions needs to be further explored.

Precursors to successful youth-adult partnerships: The role of adult warmth and expertise

Youth-Adult Partnerships (Y-APs) have been found to foster youth engagement and positive youth development. However, existing research tends to confound the characteristics of Y-APs with their general outcomes and the existing methods of evaluating Y-APs tend to be based on correlational methodologies. I sought to create a measure of Y-AP success that did not confound the characteristics of a successful Y-AP with outcomes. Using the existing literature as a guide, three components were selected for inclusion in the Y-AP success measure: 1) perceptions of productivity; 2) positive affect; and 3) having one's contributions welcomed and considered. Using this new measure, I tested a model to assess how adult warmth and expertise interacted with task difficulty to influence three components of Y-AP success. Participants included 402 university students (M = 19.27, SD = 1.28, 89.1 % female) from Brock University and Cape Breton University. Video clips of an adult, depicting all possible combinations of warmth and expertise were created for this study, as well as a pair of hypothetical tasks designed to elicit differential degrees of perceived difficulty. Participants were exposed to one video of a hypothetical adult and two hypothetical tasks and responded to the Y-AP success measures twice, for each ofthe tasks. Results from mixed-model ANOVAs revealed that the adult and task characteristics were not consistently related to all components of Y-AP success. However, several significant interactions suggested that youth perceptions of task difficulty and their impressions of adult partners influenced the extent to which they expected a Y-AP to be successful. The results are discussed in the context of how they support or conflict with the existing literature and serve as a first step in the inference of causality within the study of Y-APs.

An Examination of the Development of Online Higher Education in Canada and China: Keeping Pace and Making Space

This study examined the similarities and differences that currently exist between Chinese and Canadian online higher education, and explored the economic, political, and sociocultural environments that have shaped online education in these two jurisdictions. Furthermore, this paper discussed the efficacy of, and potential for, future development of online learning in higher education in both Canada and China. The research employed a collective case study design to gather information and data on the development of online higher education. The analysis on Contact North in Canada and the One-Man University in China provide a comparative perspective on the development of 2 typical online higher educational institutions in these two countries. The study revealed that the development of online higher education is influenced by the economic, political, and sociocultural factors of environment. Contact North and the One-Man University share similarities in many aspects, but are characteristically different. The Contact North can set an example for establishing and operating a self-regulated MOOCs platform. The study also generated implications for both organizations.