The diffusion of moisture in sorbent solids part II. activated alumina

Ordinary and thermal diffusion of moisture in activated alumina are investigated using a new diffusion cell design and scheme of analysis reported earlier. The specific form of the mass flux equation has a pronounced effect on the magnitude of the associated thermal diffusion ratio. In the case of activated alumina-moist air, if a partial pressure gradient is used, then the thermal diffusion term is small if not zero.Free, Knudsen and surface diffusion all play a part in the diffusion through activated alumina. However, surface diffusion makes the major contribution and for this reason the model in this case can be simplified to a two parameter surface model.The activation energy for surface diffusion is constant and is approximately equal to the mean isosteric heat of absorption. In addition, mean pore radius, turtuosity, and other physical constants are computed from the least square fit of experimental data. Furthermore, the model is theoretically consistent over the entire concentration range (0≦ C_A ≦ C_Asat).A new fact about activated alumina (Grade F1) it that it does not transfer moisture in a nonisothermal condition so long as the partial pressures of moisture on the two sides of the pellet are the same. There appears to be no previous report of this fact in the periodical literature.     

Resistive pulse sensing of magnetic beads and supraparticle structures using tunable pores

Tunable pores (TPs) have been used for resistive pulse sensing of 1 μm superparamagnetic beads, both dispersed and within a magnetic field. Upon application of this field, magnetic supraparticle structures (SPSs) were observed. Onset of aggregation was most effectively indicated by an increase in the mean event magnitude, with data collected using an automated thresholding method. Simulations enabled discrimination between resistive pulses caused by dimers and individual particles. Distinct but time-correlated peaks were often observed, suggesting that SPSs became separated in pressure-driven flow focused at the pore constriction. The distinct properties of magnetophoretic and pressure-driven transport mechanisms can explain variations in the event rate when particles move through an asymmetric pore in either direction, with or without a magnetic field applied. Use of TPs for resistive pulse sensing holds potential for efficient, versatile analysis and measurement of nano- and microparticles, while magnetic beads and particle aggregation play important roles in many prospective biosensing applications.     

Evaluating epistemic uncertainty under incomplete assessments

The thesis of this study is to propose an extended methodology for laboratory based Information Retrieval evaluation under incomplete relevance assessments. This new methodology aims to identify potential uncertainty during system comparison that may result from incompleteness. The adoption of this methodology is advantageous, because the detection of epistemic uncertainty – the amount of knowledge (or ignorance) we have about the estimate of a system’s performance – during the evaluation process can guide and direct researchers when evaluating new systems over existing and future test collections. Across a series of experiments we demonstrate how this methodology can lead towards a finer grained analysis of systems. In particular, we show through experimentation how the current practice in Information Retrieval evaluation of using a measurement depth larger than the pooling depth increases uncertainty during system comparison.     

Teaching and Learning Science for Transformative, Aesthetic Experience

Drawing from the Deweyan theory of experience (1934, 1938), the goal of teaching and learning for transformative, aesthetic experience is contrasted against teaching and learning from a cognitive, rational framework. A quasi-experimental design was used to investigate teaching and learning of fifth grade science from each perspective across an entire school year including three major units of instruction. Detailed comparisons of teaching are given and pre and post measures of interest in learning science, science identity affiliation, and efficacy beliefs are investigated. Tests of conceptual understanding before, after, and one month after instruction reveal teaching for transformative, aesthetic experience fosters more, and more enduring, learning of science concepts. Investigations of transfer also suggest students learning for transformative, aesthetic experiences learn to see the world differently and find more interest and excitement in the world outside of school.     

Women Students’ Interactions with Faculty and Exposure to Good Teaching at Colleges and Universities with Varying Histories of Admitting Women

This study considers how institutional histories of admitting women are associated with present college experiences, and uses data from the Wabash National Study of Liberal Arts Education to compare the experiences of women at women’s colleges or former women’s colleges to those of women at former men’s colleges and colleges that have always been coeducational. Results indicate that women attending former men’s colleges and colleges that have always been coeducational seem to experience similar or greater frequency and quality of student–faculty interaction and exposure to good teaching practices, compared to women attending women’s or former women’s colleges. Results also suggest that considering the gender enrollment histories of colleges and universities may provide valuable context for evaluating the experiences of women at women’s colleges and coeducational institutions.     

Teaching the language of mathematics at three levels of an English-medium primary school

This study, situated in a multilingual, English-medium educational context, draws on theory from mathematics and language education to capture teachers’ perspectives on the place of language in their mathematics pedagogy. The benchmark study explored this topic through surveying and interviewing teachers. Additionally, it sought to relate teachers’ views to their practice by focusing on observing three teachers’ mathematics lessons at primary one, three, and five. Findings are that mathematics teachers placed importance on teaching language, being specifically concerned with language as input and comprehension. They taught vocabulary and reading skills in supportive ways explicitly yet differently at the three grade levels. Particularly at the lower levels, teachers contextualised language in the concrete examples employed for mathematics teaching. At all three levels, prominence was given to teaching pupils how to read word problems as well as how to solve them. However, at primary three, a tension was observed between the two aims of teaching mathematical vocabulary and teaching the reading skills for word problems. This paper illustrates the tension and discusses its possible causes.     

Sustaining High-Quality Teaching and Evidence-Based Curricula: Follow-Up Assessment of Teachers in the REDI Project

Research Findings: Recent research has validated the power of evidence-based preschool interventions to improve teaching quality and promote child school readiness when implemented in the context of research trials. However, very rarely are follow-up assessments conducted with teachers in order to evaluate the maintenance of improved teaching quality or sustained use of evidence-based curriculum components after the intervention trial. In the current study, we collected follow-up assessments of teachers 1 year after their involvement in the REDI (REsearch-based, Developmentally Informed) research trial to evaluate the extent to which intervention teachers continued to implement the REDI curriculum components with high quality and to explore possible preintervention predictors of sustained implementation. In addition, we conducted classroom observations to determine whether general improvements in the teaching quality of intervention teachers (relative to control group teachers) were sustained. Results indicated sustained high-quality implementation of some curriculum components (the Promoting Alternative THinking Strategies curriculum) but decreased implementation of other components (the language/literacy components). Sustained intervention effects were evident on most aspects of general teaching quality targeted by the intervention. Practice or Policy: Implications for practice and policy are discussed.