Deep geological disposal in a multibarrier cementitious facility is being developed by a number of countries for the safe, long-term disposal of intermediate-level radioactive wastes. Intermediate-level radioactive waste, which dominates the radioactive waste inventory in the United Kingdom on a volumetric basis, is a heterogeneous wasteform that contains organic materials including cellulosic materials, encased in concrete. Under the alkaline conditions expected in the cementitious geological disposal facility (GDF), these materials will undergo abiotic, chemical hydrolysis, and will produce degradation products including isosaccharinic acid (ISA) or gluconic acid (GA) that can form soluble complexes with radionuclides. Alkaliphilic microorganisms sampled from a hyperalkaline site contaminated with lime-kiln waste, were able to degrade cellulosic material (tissue paper) in Ca(OH)2 saturated microcosms at a starting pH of 12. Enzymatic processes in these microcosms caused the production of acetate, acidification of the microcosms and a cessation of ISA production. Enrichment cultures prepared at pH 10 and inoculated with a sediment from the same hyperalkaline site were able to degrade ISA, and couple this degradation process to the reduction of electron acceptors that will dominate as the GDF progresses from an aerobic ‘open phase’ through nitrate- and Fe(III)-reducing conditions post closure. A strictly alkaliphilic bacterium belonging to the Bacillus genus was isolated from the nitrate-reducing enrichment culture, and was found to degrade a variety of organic molecules that are expected to be found in a cementitious GDF. Detailed investigation into the growth of this bacterium suggested that different mechanisms are involved in the biodegradation of ISA and GA, and that bacterial growth is coupled to a decrease in soluble U(VI) concentrations. This implies that microorganisms could have a role in attenuating the mobility of radionuclides in and around a GDF via (i) the biodegradation of cellulose and cessation of ISA production, (ii) the biodegradation of the ligands (ISA and GA) and (iii) the immobilisation of radionuclides. This should facilitate the reduction of undue pessimism in the long-term performance assessment of suchfacilities.

Geological disposal is the preferred option for the long term management of British intermediate level radioactive waste. The disposal site is currently being identified, with possible geological environments including fractured crystalline rocks and low permeability rocks such as clay. The selection of the host rock will have an impact on the design of the waste repository. This thesis investigates the ways the behaviour of repository borne gas can be affected by the repository design and the selection of the host rock. Commercially available TOUGH2 package is used to model the resaturation of the disposal facility, along with gas migration out of the repository and towards the ground surface in a generic geology. A facility located in fractured rock is estimated to resaturate within 6.5 years of its closure. The resaturation time is found to be strongly dependent on the presence and properties of a low permeability liner around the disposal vaults. The inflowing water starts gas generation processes within the repository; gas initially accumulates within the facility, but it is estimated to find its way into the host rock approximately 450 years after the facility has been closed. A maximum outflow rate is reached after approximately 1,000 years. The flow of gas migrating through the host rock is strongly affected by site-specific features. In the case of a uniform crystalline rock, gas is found to break through at the surface after 29,000 years. For a disposal site with a very slow groundwater flow rate, the resaturation phase may take several decades and gas outflow will occur much later. It is estimated that, in very low permeability environments, gas breakthrough may not occur before 100,000 years.

Carbonation is a naturally-occurring process whereby Ca-containing cement phases lose their hydration water and are converted to carbonate minerals by reaction with atmospheric CO&#8322;. As these secondary minerals develop in the microstructure of hydrated cement, porosity, pore-size distribution and permeability are decreased. These are all considered desirable properties in a wasteform. The objective of this study was to examine the effect of carbonation and different pozzolans on the leach performance and mechanical strength of ordinary Portland cement (OPC) wasteforms. Two methods of accelerated cement carbonation were used: <ol> <li>A vacuum carbonation method, where wasteforms are placed in an evacuated, sealed cell and subjected to small additions of CO&#8322; over several days at near vacuum conditions; and <li>A one-step carbonation method, where CO&#8322; gas is added to the wasteform paste as it is being mixed. </ol> Thirteen elemental constituents of interest to the safety assessments of long-term management of Ontario Power Generation's radioactive waste (Cl, N, S, Se, 13C, Th, Pb, Co, Ni, Cu, Sr, Ba and Cs) were stabilised/solidified via cement mix water. Wasteforms were produced with only OPC, OPC and fly ash, or OPC and silica fume. Most wasteforms were carbonated using one of the carbonation methods. Some wasteforms were not carbonated and served as controls. Wasteforms were subjected to either standard leach tests or compressive strength tests. The extent of carbonation was found to be about 20% for vacuum carbonation method, substantially higher than that for one-step treatment (up to about 10%). For vacuum carbonated wasteforms, carbonation occurred at the outer selvages of the wasteforms, whereas one-step treatment resulted in homogenous carbonation. Generally, compared to uncarbonated OPC wasteforms, vacuum carbonation increased leaching of elements that are anionic in cementitious conditions (Cl, N, S, Se, 13C, Th), decreased leaching of large metal cations (Sr, Ba, Cs, Pb) and had negligible effect on the leaching of the elements that form hydroxyl complexes (Co, Ni, Cu). 13C was the only anionic element whose leachability was reduced by vacuum carbonation, as it may be precipitated in the form CO32- in the large quantity of secondary carbonate minerals produced during the vacuum carbonation process. One-step carbonation did not result in substantial reductions in leachability, compared to uncarbonated OPC wasteforms. However, it had an interesting inverse effect on large metal cation leachability from fly ash- and silica fume-containing wasteforms. A model is presented that proposes that porewater pH changes can have an effect on waste element leachability because 1) the C-S-H Ca/Si ratio is dependent on the equilibrating porewater pH and 2) the degree of ion sorption on C-S-H is dependent on the C-S-H Ca/Si ratio. This model should be tested experimentally as it has important implications on wasteform design. Because of this inverse behaviour, overall neither pozzolan outperformed the other with respect to leachability. Generally, for uncarbonated wasteforms, OPC retained the elements more effectively than OPC with pozzolans. For pozzolans, the leachability of these elements from OPC with fly ash was lower than that of OPC with silica fume. Leaching of Cs was anomalously low from uncarbonated OPC wasteforms, but follow-up experimentation did not corroborate this anomaly. Further testing of these wasteforms to determine how the mineralogical fate of Cs can differ between wasteforms is recommended. All wasteforms tested were of acceptable strength (<0. 689 MPa). Fly ash, and, to a greater degree, silica fume, improved wasteform strength when compared to OPC wasteforms. Carbonation treatments had little effect on wasteform strength. This study has provided much information about the leaching characteristics of a representative set of waste elements from several cement-based wasteform treatments. Although it has not indicated a wasteform design that is ideal for all elements studied, it does suggest that some treatments may be effective for certain groups of elements. Most notably, vacuum carbonation shows promise in improving the immobilisation of isotopes of large metal cations such as Sr, Ba, Cs and Pb as well as 14C (as suggested by 13C here) in cement-based wasteforms.

Carbonation is a naturally-occurring process whereby Ca-containing cement phases lose their hydration water and are converted to carbonate minerals by reaction with atmospheric CO&#8322;. As these secondary minerals develop in the microstructure of hydrated cement, porosity, pore-size distribution and permeability are decreased. These are all considered desirable properties in a wasteform. The objective of this study was to examine the effect of carbonation and different pozzolans on the leach performance and mechanical strength of ordinary Portland cement (OPC) wasteforms. Two methods of accelerated cement carbonation were used: <ol> <li>A vacuum carbonation method, where wasteforms are placed in an evacuated, sealed cell and subjected to small additions of CO&#8322; over several days at near vacuum conditions; and <li>A one-step carbonation method, where CO&#8322; gas is added to the wasteform paste as it is being mixed. </ol> Thirteen elemental constituents of interest to the safety assessments of long-term management of Ontario Power Generation's radioactive waste (Cl, N, S, Se, 13C, Th, Pb, Co, Ni, Cu, Sr, Ba and Cs) were stabilised/solidified via cement mix water. Wasteforms were produced with only OPC, OPC and fly ash, or OPC and silica fume. Most wasteforms were carbonated using one of the carbonation methods. Some wasteforms were not carbonated and served as controls. Wasteforms were subjected to either standard leach tests or compressive strength tests. The extent of carbonation was found to be about 20% for vacuum carbonation method, substantially higher than that for one-step treatment (up to about 10%). For vacuum carbonated wasteforms, carbonation occurred at the outer selvages of the wasteforms, whereas one-step treatment resulted in homogenous carbonation. Generally, compared to uncarbonated OPC wasteforms, vacuum carbonation increased leaching of elements that are anionic in cementitious conditions (Cl, N, S, Se, 13C, Th), decreased leaching of large metal cations (Sr, Ba, Cs, Pb) and had negligible effect on the leaching of the elements that form hydroxyl complexes (Co, Ni, Cu). 13C was the only anionic element whose leachability was reduced by vacuum carbonation, as it may be precipitated in the form CO32- in the large quantity of secondary carbonate minerals produced during the vacuum carbonation process. One-step carbonation did not result in substantial reductions in leachability, compared to uncarbonated OPC wasteforms. However, it had an interesting inverse effect on large metal cation leachability from fly ash- and silica fume-containing wasteforms. A model is presented that proposes that porewater pH changes can have an effect on waste element leachability because 1) the C-S-H Ca/Si ratio is dependent on the equilibrating porewater pH and 2) the degree of ion sorption on C-S-H is dependent on the C-S-H Ca/Si ratio. This model should be tested experimentally as it has important implications on wasteform design. Because of this inverse behaviour, overall neither pozzolan outperformed the other with respect to leachability. Generally, for uncarbonated wasteforms, OPC retained the elements more effectively than OPC with pozzolans. For pozzolans, the leachability of these elements from OPC with fly ash was lower than that of OPC with silica fume. Leaching of Cs was anomalously low from uncarbonated OPC wasteforms, but follow-up experimentation did not corroborate this anomaly. Further testing of these wasteforms to determine how the mineralogical fate of Cs can differ between wasteforms is recommended. All wasteforms tested were of acceptable strength (<0. 689 MPa). Fly ash, and, to a greater degree, silica fume, improved wasteform strength when compared to OPC wasteforms. Carbonation treatments had little effect on wasteform strength. This study has provided much information about the leaching characteristics of a representative set of waste elements from several cement-based wasteform treatments. Although it has not indicated a wasteform design that is ideal for all elements studied, it does suggest that some treatments may be effective for certain groups of elements. Most notably, vacuum carbonation shows promise in improving the immobilisation of isotopes of large metal cations such as Sr, Ba, Cs and Pb as well as 14C (as suggested by 13C here) in cement-based wasteforms.

In the field of second language acquisition, there are few studies focusing on Chinese English-as-an-additional-language (EAL) graduate students’ communication strategy use, strategy use across different disciplines, and the relationships between communication strategy use and learners’ speaking performance. To fill the gap identified in the literature reviewed, this study examined the communication strategies used by 11 Chinese EAL graduate students from the Departments of Electrical Engineering and Education in the completion of two informal debate tasks with a questionnaire adapted from Nakatani’s (2006) Oral Communication Strategy Inventory and two post-task communication strategy recall questionnaires. Results from the study indicate that participants used eight categories of communication strategies, with fluency-oriented strategies the most frequently used strategy category and translation the least frequently used strategy category. Advanced English-language proficiency level learners used more social affective, message reduction and alteration, and negotiation of meaning strategies than learners at high-intermediate proficiency levels, to a degree that was statistically significant. No significant difference was identified in the overall communication strategy use but in one instance of individual strategy use (i.e., clarifying stance) across two disciplines. Significantly positive relationships were identified among certain categories of communication strategies (i.e., social affective, negotiation of meaning, accuracy-oriented strategies, and message reduction and alteration strategies), individual strategies (i.e., turn yielding, exemplifying, clarifying meaning, correcting others, referring to notes for accuracy/fluency, message reduction and alteration), and participants’ speaking performance. In addition, the retrospective results from the post-task strategy recall questionnaires suggest that participants in this study are not fully aware of their communication strategy use. The findings in this study can inform language practitioners’ of communication strategies used by Chinese graduate students majoring in Electrical Engineering and Education. Implications and future research directions are discussed in light of the findings derived from the present study that can further contribute to research about EAL learners’ communication strategies used at the graduate level. / Graduate / 0290 / cihangzh@uvic.ca

In the field of second language acquisition, there are few studies focusing on Chinese English-as-an-additional-language (EAL) graduate students’ communication strategy use, strategy use across different disciplines, and the relationships between communication strategy use and learners’ speaking performance. To fill the gap identified in the literature reviewed, this study examined the communication strategies used by 11 Chinese EAL graduate students from the Departments of Electrical Engineering and Education in the completion of two informal debate tasks with a questionnaire adapted from Nakatani’s (2006) Oral Communication Strategy Inventory and two post-task communication strategy recall questionnaires. Results from the study indicate that participants used eight categories of communication strategies, with fluency-oriented strategies the most frequently used strategy category and translation the least frequently used strategy category. Advanced English-language proficiency level learners used more social affective, message reduction and alteration, and negotiation of meaning strategies than learners at high-intermediate proficiency levels, to a degree that was statistically significant. No significant difference was identified in the overall communication strategy use but in one instance of individual strategy use (i.e., clarifying stance) across two disciplines. Significantly positive relationships were identified among certain categories of communication strategies (i.e., social affective, negotiation of meaning, accuracy-oriented strategies, and message reduction and alteration strategies), individual strategies (i.e., turn yielding, exemplifying, clarifying meaning, correcting others, referring to notes for accuracy/fluency, message reduction and alteration), and participants’ speaking performance. In addition, the retrospective results from the post-task strategy recall questionnaires suggest that participants in this study are not fully aware of their communication strategy use. The findings in this study can inform language practitioners’ of communication strategies used by Chinese graduate students majoring in Electrical Engineering and Education. Implications and future research directions are discussed in light of the findings derived from the present study that can further contribute to research about EAL learners’ communication strategies used at the graduate level. / Graduate / 0290 / cihangzh@uvic.ca

Testing, at times, can be a complicated matter. It takes a lot of time, precision and trial and error to adequately create a valid and reliable test. When creating a test, we should be aware of the impact that it is going to have on our teaching and whether it will be positive or negative. The goal of this project was to create four good intermediate Spanish diagnostic pre-tests that could be taken at the Brigham Young University Humanities Computer Testing Laboratory. The purpose of these pre-tests was to ascertain the grammatical strengths and weaknesses of our Fall Semester 2012 Spanish 205 students' in regards to specific grammatical principles covered throughout the course. Then, the results could be used to determine how to best plan class time and promote good instructional decisions. This report covers the necessary steps it took to develop and validate said pre-tests and concludes with reviewing the results of the validity and reliability process and gives recommendations for future application of the pre-tests designed and implemented.

Approved for public release, distribution is unlimited / The United States Army is making changes in the Officer Education System for 2nd lieutenants to majors. These changes affect the size of Transient, Holdee and Student account (THS). The current Officer Basic Course changes to a two-phased system called Basic Officer Leadership Course (BOLC II and III). A twenty-week Captains' Career Course (CCC) replaces the current CCC and Combined Arms and Service Staff School (CAS3). Currently, Command and General Staff College (CGSC), where 50% of a year group attends resident CGSC, shifts to a two-phased approach with a Common Core Course and a Career Field Qualification Course. This thesis includes an Excel simulation model producing monthly predictions for six years for officers in THS account because of schooling. Assignments are Permanent Change of Station (PCS), Temporary Duty (TDY) Enroute, or TDY and Return. Therefore, if 30% of majors attend Officer Education System (OES) as a PCS or TDY Enroute, the THS account sees a man-year increase of between 166 and 552 personnel. For CCC, if 30% of captains attend CCC as PCS/TDY Enroute, THS shows a man-year decrease of between 1162 and 1171. When the new BOLC education system was simulated, the THS account showed a man-year increase of between 172 and 242 when compared to the current OBC. / Army Deputy Chief of Staff, G-1 / Major, United States Army

Book talks have become widespread in school as they are considered to be beneficial for pupils’ potential to develop their analytical and communicative skills. The study aims to investigate book talks from a teacher’s perspective in order to compare different teachers’ experiences of book talks in relation to research. To explore this, interviews were conducted with four teachers who have experience of book talks in the intermediate level of compulsory school. To identify the teachers’ perspectives on book talks and what they value in the method, their interviews were analysed, among other things, in relation to Michael Tengberg’s concept of readings and Louise Rosenblatt’s theory of efferent and aesthetic reading. The result shows that the teachers’ descriptions of the conversations encompass a variety of readings and reading activities. They choose to highlight different themes from the literature, ranging from questions of basic values to word comprehension. The teachers support their pupils through scaffolding in the conversations so that they can potentially develop new knowledge and become more autonomous in their way of working. Autonomy in the conversations among older pupils can also be identified as a difference between grades four and six. The teachers think that book talks are rewarding because the pupils have a chance to speak and share each other’s experiences. The challenges include finding good books and getting the pupils to feel a sense of engagement.

This article focuses on party competition in Bolivia from a multilevel approach with department (intermediate level) as the territorial unit of analysis from 2005 to 2015. The objective is to demonstrate the (in)congruence of an institutional level overlooked by the literature on multilevel studies, for which two indices of measurement are used: Summary Measure of Congruence (Gibson and Suarez-Cao 2010) in a one version and Dissimilarity Index (Johnston 1980) in two versions, nationally aggregated and departmentally disaggregated, with voting data from all competing parties (DISa) and only from those with double competition (DISb). The argument handled is that if an institutional level is important enough to be introduced to the electoral framework of a country, it should also be important enough for academic interest, especially in their relation with the rest of the system. From this, the study concluded that the importance of this institutional level depends on the degree of autonomy it has and the interest of the partisan actors and regional elites. / El presente artículo aborda la competencia partidista en Bolivia desde un enfoque multinivel a partir del departamento (nivel intermedio) como unidad territorial de análisis de 2005 a 2015. El objetivo es dar cuenta de la (in)congruencia que presenta un nivel institucional soslayado por la literatura existente sobre los estudios multinivel. Con este propósito se utilizan dos herramientas de medición: la Medida de Congruencia (Gibson y Suárez-Cao 2010) en una sola versión y el Índice de Disimilitud (Johnston 1980) en dos versiones, agregada a nivel nacional y desagregada por departamentos, con la introducción de datos de todos los partidos (DISa) y de los partidos con doble competencia (DISb). El argumento que se maneja es que si un nivel institucional es lo suficientemente importante para ser introducido al ámbito electoral de un país, debería serlo también para el interés académico y más en su relación con el resto del sistema. A partir de esto, el estudio ha llegado a la conclusión de que la importancia de este nivel institucional depende del grado de autonomía que posea y del interés de los actores partidistas y las élites regionales.