The microstructure-property relationship for interpenetrating phase composites (IPCs) is currently poorly understood. In an attempt to improve this understanding this study focused on one particular part of this relationship: the effect of phase shape on the elastic and plastic behaviour. A review of previous research showed that investigations had linked phase shape to the elastic and plastic behaviour of various inclusion reinforced composites, but that no similar work had been completed for IPCs. <p> To study the complex response of the IPC microstructure under load, a numerical modelling analysis using the finite element method (FEM) was undertaken. Two three-dimensional models of IPCs were created, the first consisting of an interconnected spherical phase with the interstitial space forming the other interconnected phase, and the second replacing the spherical phase with an interconnected cylindrical phase. With the simulation of a uniaxial tension test under elastic and plastic conditions, these two models exhibited different responses based on the shape of the phases. <p> Results from an analysis of the macroscopic behaviour identified that the cylindrical model produced greater effective properties than the spherical model at the same volume fraction. The influence of phase shape was connected to the increased contiguity of the superior phase within the IPC for the cylindrical model, which allowed similar levels of long-range continuity with smaller amounts of the superior phase (compared to the spherical model). <p> An examination of microstructural stress distributions showed that preferential stress transfer occurred along paths of low compliance. This provided an explanation of how the improved contiguity of the stiffer (or stronger) phase could enhance the macroscopic effective properties of an IPC. Contiguity of the stronger phase was particularly important for plastic behaviour, where early yielding of the weaker phase requires the stronger phase to carry nearly all the load within itself.

The microstructure-property relationship for interpenetrating phase composites (IPCs) is currently poorly understood. In an attempt to improve this understanding this study focused on one particular part of this relationship: the effect of phase shape on the elastic and plastic behaviour. A review of previous research showed that investigations had linked phase shape to the elastic and plastic behaviour of various inclusion reinforced composites, but that no similar work had been completed for IPCs. <p> To study the complex response of the IPC microstructure under load, a numerical modelling analysis using the finite element method (FEM) was undertaken. Two three-dimensional models of IPCs were created, the first consisting of an interconnected spherical phase with the interstitial space forming the other interconnected phase, and the second replacing the spherical phase with an interconnected cylindrical phase. With the simulation of a uniaxial tension test under elastic and plastic conditions, these two models exhibited different responses based on the shape of the phases. <p> Results from an analysis of the macroscopic behaviour identified that the cylindrical model produced greater effective properties than the spherical model at the same volume fraction. The influence of phase shape was connected to the increased contiguity of the superior phase within the IPC for the cylindrical model, which allowed similar levels of long-range continuity with smaller amounts of the superior phase (compared to the spherical model). <p> An examination of microstructural stress distributions showed that preferential stress transfer occurred along paths of low compliance. This provided an explanation of how the improved contiguity of the stiffer (or stronger) phase could enhance the macroscopic effective properties of an IPC. Contiguity of the stronger phase was particularly important for plastic behaviour, where early yielding of the weaker phase requires the stronger phase to carry nearly all the load within itself.

<p><font face="Times New Roman"> <p align="left">This study looks at the effect of a cross-cultural instructional approach on the learners&rsquo / conceptions of lightning and attitude towards science. It explored Basotho conceptions of lightning and thunder under the following themes: nature of lightning, protection against lightning, animalistic/humanistic behaviour of lighting and nature of wounds inflicted by lightning.</p> </font></p>

Spatial analysis methods used for detecting, interpolating or predicting local patterns require a delineation of a neighbourhood defining the extent of spatial interaction in geographic data. The most common neighbourhood delineation techniques include fixed distance bands, k-nearest neighbours, or spatial adjacency (contiguity) matrices optimized to represent spatial dependency in data. However, these standard approaches do not take into consideration the geographic or environmental constraints such as impassable mountain ranges, road networks or coastline barriers. Specifically, complex marine landscapes and coastlines present common problematic neighbourhood definitions for standard neighbourhood matrices used in the spatial analysis of marine environments. Therefore, the goal of our research is to present a new approach to constraining spatial neighbourhoods when conducting geographical analysis in marine environments. To meet this goal, we developed methods and software (COnstraining SpatIal NEighbourhoods - COSINE) for modifying spatial neighbourhoods, and demonstrate their utility in two case studies. Our method enables delineation of neighbourhoods that are constrained by coastlines and the direction of marine currents. Our software calculates and evaluates whether neighbouring features are separated by land, or are within a user defined angle that excludes interaction based on directional processes. Using decision rules a modified spatial weight matrix is created, either in binary or row-standardized format. Within open source software (R), a graphical user interface enables users to modify the standard spatial neighbourhood definition distance, inverse distance and k-nearest neighbour. Two case studies are presented to demonstrate the usefulness of the new approach for detecting spatial patterns: the first case study observes marine mammals’ abundance and the second, oil spill observation. Our results indicate that constraining spatial neighbourhoods in marine environments is particularly important at larger spatial scales. The COSINE tool has many applications for modelling both environmental and human processes. / Graduate / 0463 / 0366 / suarezc@uvic.ca

This essay deals with subject-verb concord in written compositions by Swedish students at Uppsala University. The essay investigates the possibility that students who continue studying English beyond the A level at the university make fewer errors than students who do not continue. In order to minimize the influence of the students’ gender and first language, only essays written by female students were included in the study; in addition, all students included had Swedish as their first language, and so did their parents. 25 essays by students who continued their studies and 25 essays by students who may not have done so were chosen. All 50 essays were examined for both correct and incorrect instances concerning concord between subjects and verbs in the present tense. The primary verbs to be, to do and to have were analysed as well as regular and irregular verbs. The results show that the 25 students who continued beyond the A level made fewer errors than the 25 students who may not have continued. The results also indicate that subject-verb concord is not a serious problem for Swedish learners.

Doctor Educationis / This study looks at the effect of a cross-cultural instructional approach on the learners’ conceptions of lightning and attitude towards science. It explored Basotho conceptions of lightning and thunder under the following themes: nature of lightning, protection against lightning, animalistic/humanistic behaviour of lighting and nature of wounds inflicted by lightning.

Philosophiae Doctor - PhD / The study investigated the impact of a dialogical argumentation instructional model (DAIM) as an intervention teaching strategy to assist pre-service science teachers to implement integrated science-indigenous knowledge (IK) lessons during their seven week block teaching practice at schools in the Western Cape. This imperative is found in Specific Aim 3 of the Curriculum and Assessment Policy Statement (CAPS) of the South African School Curriculum (Department of Basics Education, 2011). The study focussed on the pre-post conceptions of pre-service science teachers’ conceptions of the nature of science and the nature of indigenous knowledge. In addition the study examined pre-service teachers’ sense of self-efficacy in deploying a dialogical argumentation instructional model to implement an integrated science-IK lesson. The sample consisted of a cohort of thirty (30) Post-graduate Certificate of Education (PGCE) students training to teach at the Further Education and Training (FET) phase of school. They were a combined class enrolled for method in Natural Sciences, Life Sciences and Physical Sciences. A mixed methods approach was used to generate quantitative and qualitative data using a series of questionnaires, reflective diaries, journals and focus group interviews. Transcripts provided a rich bank of data of which only exemplars were used to highlight trends and to illustrate how theoretical constructs were used as analytical tools. The theoretical constructs used were Toulmin’s (1958/2003) Argumentation Pattern (TAP), Ogunniyi’s (1997) Contiguity Argumentation Theory (CAT) and Banduras’ Social Cognitive Theory (1986). The findings showed that the pre-service teachers appeared to overestimate their sense of self-efficacy (i.e. the ease and comfort) in using DAIM to implement a science- IK curriculum at the pre-test than at the post-test. The study also identified important implications for policy, teacher training programmes, teaching practice, pre-service science teachers, learners and further research. Furthermore, the pre-service reflective experiences indicated their increased awareness of the challenges and successes related to using dialogical argumentation to integrate a science-IK lesson. The most important contribution of this study to an argumentation paradigm was the emergence of a visual model called the Pyramid Argumentation Model that succinctly connected the apparent disparate module units in a holistic way (To be discussed in follow-up reports). The findings revealed numerous complexities as the participants navigated their own cosmologies of a scientific worldview and that of their indigenous knowledge worldview. Finally, the findings have not only corroborated the findings in earlier studies with respect to the merits and demerits of argumentation instruction but also identified various challenges that prospective and even practicing teachers might encounter in an attempt to make school science relevant to the sociocultural environment of learners especially those living in indigenous or traditional societies like the participants in this study.

Magister Educationis - MEd / Over the last 15 years the Department of Education has rolled out various projects in an attempt to improve Mathematics and Science results and to increase the amount of learners who exit their schooling with those subjects. The 2010 - 2014 matric results show a decrease in the number of students who exiting with Science. One of the factors that might influence the learners' decision to do science can be ascribed to the methodologies that the teachers are using to teach Science. In response to the latter, this study investigated the cognitive shifts of grade two learners' conceptual knowledge of the day and night cycle after being exposed to a Dialogical Argumentation Based Instructional Model. The Contiguity Argumentation Theory (CAT) and Toulmin's Argumentation Pattern (TAP) were used as a framework to capture and interrogate learners' arguments with argumentation frames developed to categorize the learners’ argument responses. Analytical approaches were used to assess learners' argumentation skills along four stages namely intra-argumentation, inter-argumentation, whole class discussion and trans-argumentation. The study employed both quantitative and qualitative methods. The data was collected from grade 2 learners in a primary school in Cape Town, Western Cape Province in the form of a pre-post questionnaire, focus group interviews and classroom observation. The major findings of this study indicated that ● The Dialogical Argumentation Instructional model can assist learners to develop argumentative skills. ● The grade two learners in this study had alternative conceptions regarding the day and night cycle which is not scientifically valid. ● The views that learners hold are egocentric. ● DAIM is an effective teaching strategy to help learners to eliminate the misconceptions This study has shown that the Dialogical Argumentation Instructional Model (DAIM) seems to be effective in enhancing the learners’ understanding of the day and night cycle. / National Research Foundation

Magister Educationis - MEd / The clamour in the country about the poor performance of learners in the area of physical science is a concern and this problem had been attributed to different facets of learning which include the amendment of curriculum over the years. But my question is; can the curriculum amendment succeed without effective teaching approaches? This poignant question formed the central concern for this investigation. This study examined two cohorts of grade seven learners’ conceptions of conservation of energy using a Dialogical Argumentation Instructional Model (DAIM) as well as the Traditional Lecture Method (TLM). The study involved 48 learners selected from two public schools in Cape Town. Using a quasi-experimental (Non-equivalent groups) design, the study examined the two groups from different schools (24 learners in each). It exposed one group to the Traditional Lecture Method (TLM) and the other group to a Dialogical Argumentation Instructional Model (DAIM) which was based on two argumentation frameworks– Toulmin’s Argumentation Pattern (TAP) and Contiguity Argumentation Theory (CAT).

There is an increasing interest in using video games as a means to deliver training to individuals learning new skills or tasks. However, current research lacks a clear method of developing effective instructional material when these games are used as training tools and explaining how gameplay may affect learning. The literature contains multiple approaches to training and GBT but generally lacks a foundational-level and theoretically relevant approach to how people learn specifically from video games and how to design instructional guidance within these gaming environments. This study investigated instructional delivery within GBT. Video games are a form of multimedia, consisting of both imagery and sounds. The Cognitive Theory of Multimedia Learning (CTML; Mayer 2005) explicitly describes how people learn from multimedia information, consisting of a combination of narration (words) and animation (pictures). This study empirically examined the effects of the modality and temporal contiguity principles on learning in a game-based virtual environment. Based on these principles, it was hypothesized that receiving either voice or embedded training would result in better performance on learning measures. Additionally, receiving a combination of voice and embedded training would lead to better performance on learning measures than all other instructional conditions. A total of 128 participants received training on the role and procedures related to the combat lifesaver - a non-medical soldier who receives additional training on combat-relevant lifesaving medical procedures. Training sessions involved an instructional presentation manipulated along the modality (voice or text) and temporal contiguity (embedded in the game or presented before gameplay) principles. Instructional delivery was manipulated in a 2x2 between-subjects design with four instructional conditions: Upfront-Voice, Upfront-Text, Embedded-Voice, and Embedded-Text. Results indicated that: (1) upfront instruction led to significantly better retention performance than embedded instructional regardless of delivery modality; (2) receiving voice-based instruction led to better transfer performance than text-based instruction regardless of presentation timing; (3) no differences in performance were observed on the simple application test between any instructional conditions; and (4) a significant interaction of modality-by-temporal contiguity was obtained. Simple effects analysis indicated differing effects along modality within the embedded instruction group, with voice recipients performing better than text (p = .012). Individual group comparisons revealed that the upfront-voice group performed better on retention than both embedded groups (p = .006), the embedded-voice group performed better on transfer than the upfront text group (p = .002), and the embedded-voice group performed better on the complex application test than the embedded-text group (p =.012). Findings indicated partial support for the application of the modality and temporal contiguity principles of CTML in interactive GBT. Combining gameplay (i.e., practice) with instructional presentation both helps and hinders working memory's ability to process information. Findings also explain how expanding CTML into game-based training may fundamentally change how a person processes information as a function of the specific type of knowledge being taught. Results will drive future systematic research to test and determine the most effective means of designing instruction for interactive GBT. Further theoretical and practical implications will be discussed.