DEVELOPMENT OF A MECHANISM AND PROCESS TO CONTINUOUSLY PRODUCE SPHERICAL, TORREFIED BIOMASS PELLETS

A recently developed novel biomass fuel pellet, the Q’ Pellet, offers significant improvements over conventional white pellets, with characteristics comparable to those of coal. The Q’ Pellet was initially created at bench scale using a proprietary die and punch design, in which the biomass was torrefied in-situ¬ and then compressed. To bring the benefits of the Q’ Pellet to a commercial level, it must be capable of being produced in a continuous process at a competitive cost. A prototype machine was previously constructed in a first effort to assess continuous processing of the Q’ Pellet. The prototype torrefied biomass in a separate, ex-situ reactor and transported it into a rotary compression stage. Upon evaluation, parts of the prototype were found to be unsuccessful and required a redesign of the material transport method as well as the compression mechanism. A process was developed in which material was torrefied ex-situ and extruded in a pre-compression stage. The extruded biomass overcame multiple handling issues that had been experienced with un-densified biomass, facilitating efficient material transport. Biomass was extruded directly into a novel re-designed pelletizing die, which incorporated a removable cap, ejection pin and a die spring to accommodate a repeatable continuous process. Although after several uses the die required manual intervention due to minor design and manufacturing quality limitations, the system clearly demonstrated the capability of producing the Q’ Pellet in a continuous process. Q’ Pellets produced by the pre-compression method and pelletized in the re-designed die had an average dry basis gross calorific value of 22.04 MJ/kg, pellet durability index of 99.86% and dried to 6.2% of its initial mass following 24 hours submerged in water. This compares well with literature results of 21.29 MJ/kg, 100% pellet durability index and <5% mass increase in a water submersion test. These results indicate that the methods developed herein are capable of producing Q’ Pellets in a continuous process with fuel properties competitive with coal.

An Exploration of the challenges associated with software logging in large systems

Over the past few years, logging has evolved from from simple printf statements to more complex and widely used logging libraries. Today logging information is used to support various development activities such as fixing bugs, analyzing the results of load tests, monitoring performance and transferring knowledge. Recent research has examined how to improve logging practices by informing developers what to log and where to log. Furthermore, the strong dependence on logging has led to the development of logging libraries that have reduced the intricacies of logging, which has resulted in an abundance of log information. Two recent challenges have emerged as modern software systems start to treat logging as a core aspect of their software. In particular, 1) infrastructural challenges have emerged due to the plethora of logging libraries available today and 2) processing challenges have emerged due to the large number of log processing tools that ingest logs and produce useful information from them. In this thesis, we explore these two challenges. We first explore the infrastructural challenges that arise due to the plethora of logging libraries available today. As systems evolve, their logging infrastructure has to evolve (commonly this is done by migrating to new logging libraries). We explore logging library migrations within Apache Software Foundation (ASF) projects. We i find that close to 14% of the pro jects within the ASF migrate their logging libraries at least once. For processing challenges, we explore the different factors which can affect the likelihood of a logging statement changing in the future in four open source systems namely ActiveMQ, Camel, Cloudstack and Liferay. Such changes are likely to negatively impact the log processing tools that must be updated to accommodate such changes. We find that 20%-45% of the logging statements within the four systems are changed at least once. We construct random forest classifiers and Cox models to determine the likelihood of both just-introduced and long-lived logging statements changing in the future. We find that file ownership, developer experience, log density and SLOC are important factors in determining the stability of logging statements.

Accommodating Muslim Minorities in Secular Societies: Public Education in England, Scotland, Ontario, and Quebec

Abstract This thesis examines one of the most sensitive challenges facing contemporary democracies: the accommodation of Muslim minorities in public institutions and services. It focuses on the field of education, and on two particular issues: the public funding of Islamic schools and the accommodation of Muslim needs in public secular schools. The analysis is based on an examination of outcomes in four jurisdictions that differ significantly in the level of accommodation that has emerged: England, Scotland, Ontario, and Quebec. I seek to explain why such variation in outcomes exists among these four cases. I draw on four bodies of literature to underpin the theoretical framework: historical institutionalism, political mobilization by civil society, political parties, and ideationalism. My argument can be summarized simply; historic church-state settlements, unique in each case, are the most important factor explaining the variation in outcomes in England, Scotland, Ontario, and Quebec. In some cases, the historic church-state template is incrementally adapted to accommodate Muslim minorities. In other cases, relatively little accommodation occurs and the path-dependent trajectory of church-state relations remains entrenched. While the historic church-state template is a necessary factor in the explanation, it does not fully account for the variation. For a more complete picture, I demonstrate that there are several additional key factors that also shape the outcomes: first, national identity and public attitudes towards immigration and immigrants; second, the extent of mobilization by political agents, such as civil society organizations and historic churches; and third, the response of political parties to demands by Muslims for institutional accommodation. Ultimately, I conclude that Muslims in these jurisdictions are receiving some accommodation, but the process is slow and partial. This thesis makes important theoretical and empirical contributions to the discussion of Muslim integration in liberal democratic states. First, a framework has yet to be developed that considers the theoretical implications of institutional accommodation of Muslims; I address this gap. Second, this research demonstrates the utility of historical institutionalism in explaining the adaptation of church-state templates to accommodate Muslims’ demands. Last, this study makes an original contribution by comparing the cases of England, Scotland, Ontario, and Quebec in the accommodation of Muslims in education. A comparison of Canada with the United Kingdom has not yet been done.