Development of Innovative Load Transfer Mechanism to Reduce Hurricane-Induced Failures in New and Existing Residential Construction

Implicit in current design practice of minimum uplift capacity, is the assumption that the connection's capacity is proportional to the number of fasteners per connection joint. This assumption may overestimate the capacity of joints by a factor of two or more and maybe the cause of connection failures in extreme wind events. The current research serves to modify the current practice by proposing a realistic relationship between the number of fasteners and the capacity of the joint. The research is also aimed at further development of non-intrusive continuous load path (CLP) connection system using Glass Fiber Reinforced Polymer (GFRP) and epoxy. Suitable designs were developed for stud to top plate and gable end connections and tests were performed to evaluate the ultimate load, creep and fatigue behavior. The objective was to determine the performance of the connections under simulated sustained hurricane conditions. The performance of the new connections was satisfactory.

Évaluation d’une nouvelle méthode de calcul des assemblages en bois à l’aide de connecteurs de petits diamètres

Les charpentes en bois doivent inévitablement inclure des assemblages pouvant transférer les charges entre les éléments de façon adéquate pour assurer l’intégrité de la structure. Les assemblages sont une partie critique des structures en bois puisque dans la plupart des cas, ce sont ceux-ci qui permettent de dissiper l’énergie et d’obtenir un mode de rupture ductile sous les charges sismiques. Ce mode de rupture est préférable, puisqu’il donne lieu à une grande déformation avant effondrement, permettant ainsi une évacuation des occupants en toute sécurité lors de tremblement de terre. Les assemblages à petits diamètres tels que les clous, les rivets et les vis sont fréquemment utilisés dans les constructions en bois et on suppose qu’ils amènent une rupture ductile bien qu’il soit impossible pour les concepteurs de prédire exactement le mode de rupture à l’aide de la méthode de calcul actuelle. De plus, les rivets ont une application très limitée dû au fait que la méthode de calcul utilisée actuellement s’applique à des configurations, essences et types de produits de bois très spécifiques. L’objectif de ce projet est d’évaluer une nouvelle méthode de calcul proposée par des chercheurs de Nouvelle-Zélande, Zarnani et Quenneville, pour les assemblages à rivets, mais adaptable pour les assemblages de bois à attaches de petits diamètres. Elle permet au concepteur de déterminer avec précision le mode de rupture des assemblages de différentes configurations avec différents produits de bois. Plus de 70 essais sur les assemblages à rivets et à clous résistants à des charges variant de 40kN à 800kN ont été effectués dans le cadre de ce projet de recherche afin de valider l’utilisation de cette méthode avec le produit du bois lamellé-collé canadien Nordic Lam et la comparer avec celle présentement utilisée au Canada. Les modes de rupture ductile, fragile et mixte ont été prévus avec l’emphase sur le mode fragile puisque c’est celui-ci qui est le plus variable et le moins étudié. Les assemblages en bois lamellé-collé Nordic Lam étaient cloués ou rivetés selon différentes configurations variant de 18 à 128 clous ou rivets. Les résultats démontrent une bonne prédiction de la résistance et des modes de rupture des assemblages à clous et à rivets. Pour quelques configurations des assemblages à rivets, les prédictions de la nouvelle méthode sont plus élevées qu’avec la méthode actuelle. Les assemblages à clous ont démontré des ruptures de la tige de clous au niveau du plan de cisaillement lors de tous les essais effectués, ce qui ne correspond pas à un mode ductile ou fragile prévue par la méthode de calcul.

Emissions from realistic operation of residential wood pellets heating systems

Emissions from residential combustion appliances vary significantly depending on the firing behaviours and combustion conditions, in addition to combustion technologies and fuel quality. Although wood pellet combustion in residential heating boilers is efficient, the combustion conditions during start-up and stop phases are not optimal and produce significantly high emissions such as carbon monoxide and hydrocarbon from incomplete combustion. The emissions from the start-up and stop phases of the pellet boilers are not fully taken into account in test methods for ecolabels which primarily focus on emissions during operation on full load and part load. The objective of the thesis is to investigate the emission characteristics during realistic operation of residential wood pellet boilers in order to identify when the major part of the annual emissions occur. Emissions from four residential wood pellet boilers were measured and characterized for three operating phases (start-up, steady and stop). Emissions from realistic operation of combined solar and wood pellet heating systems was continuously measured to investigate the influence of start-up and stop phases on total annual emissions. Measured emission data from the pellet devices were used to build an emission model to predict the annual emission factors from the dynamic operation of the heating system using the simulation software TRNSYS. Start-up emissions are found to vary with ignition type, supply of air and fuel, and time to complete the phase. Stop emissions are influenced by fan operation characteristics and the cleaning routine. Start-up and stop phases under realistic operation conditions contribute 80 – 95% of annual carbon monoxide (CO) emission, 60 – 90% total hydrocarbon (TOC), 10 – 20% of nitrogen oxides (NO), and 30 – 40% particles emissions. Annual emission factors from realistic operation of tested residential heating system with a top fed wood pelt boiler can be between 190 and 400 mg/MJ for the CO emissions, between 60 and 95 mg/MJ for the NO, between 6 and 25 mg/MJ for the TOC, between 30 and 116 mg/MJ for the particulate matter and between 2x10-13 /MJ and 4x10-13 /MJ for the number of particles. If the boiler has the cleaning sequence with compressed air such as in boiler B2, annual CO emission factor can be up to 550 mg/MJ. Average CO, TOC and particles emissions under realistic annual condition were greater than the limits values of two eco labels. These results highlight the importance of start-up and stop phases in annual emission factors (especially CO and TOC). Since a large or dominating part of the annual emissions in real operation arise from the start-up and stop sequences, test methods required by the ecolabels should take these emissions into account. In this way it will encourage the boiler manufacturers to minimize annual emissions. The annual emissions of residential pellet heating system can be reduced by optimizing the number of start-ups of the pellet boiler. It is possible to reduce up to 85% of the number of start-ups by optimizing the system design and its controller such as switching of the boiler pump after it stops, using two temperature sensors for boiler ON/OFF control, optimizing of the positions of the connections to the storage tank, increasing the mixing valve temperature in the boiler circuit and decreasing the pump flow rate. For 85 % reduction of start-ups, 75 % of CO and TOC emission factors were reduced while 13% increase in NO and 15 % increase in particle emissions was observed.

Global review of permian Tyloplecta muir-wood and cooper, 1960 (Brachiopoda): morphology, palaeobiogeographical and palaeogeographical implications

A global review of the stratigraphical and geographical distribution of Tyloplecta reveals that the genus ranges in age from Kungurian to Changhsingian (Middle to Late Permian). Tyloplecta first evolved in South China in the Kungurian (late Early Permian). The genus went through its first diversification in the Guadalupian, suffered a major extinction at the end of the Guadalupian, and re-diversified in the Wuchiapingian. T. yangtzeensis persisted into the Changhsingian as the only survivor of the genus involved in the end-Permian mass extinction. Palaeogeographically, South China is not only the centre of origin for the genus but also an area of diversification and evolution. In addition to South China, Tyloplecta has also been recorded from the Far East Russia, Japan, central Thailand, Laos, Cambodia, Qiangtang Terrane of Tibet, Salt Range, Iran, Armenia, Hungary, Yugoslavia, and Slovenia. This geographic spread suggests that Tyloplecta was primarily restricted to the Palaeotethys and is indicative of warm-water palaeoequatorial conditions. Its presence in some of the northeast Asian terranes (e.g., parts of Japan and Far East Russia) and in the Salt Range (Pakistan) and central and north Iran (part of the Cimmerian microcontinents) demonstrate that the genus invaded the middle palaeolatitudinal regions in both hemispheres during the late Middle Permian in response to increased shallow marine biotic communications between Cathaysia in the eastern Palaeotethys and southern Angaraland, and between Cathaysia and Peri-Gondwanaland. The invasion of Tyloplecta (and some other taxa) into the southern shore waters of Angaraland may be explained by assuming ocean surface current connections and close palaeogeographical proximities between the South China, Sino-Korea and Bureya blocks. In comparison, the invasion of Tyloplecta into the Peri-Gondwanaland region is more likely a result of reduced palaeogeographical distance between South China and Peri-Gondwanaland and the appearance of the Cimmerian microcontinents as migratory stepping stones.

Particle number and mass emission factors from combustion of wood samples collected from Queensland forest

Knowledge of particle emission characteristics associated with forest fires and in general, biomass burning, is becoming increasingly important due to the impact of these emissions on human health. Of particular importance is developing a better understanding of the size distribution of particles generated from forest combustion under different environmental conditions, as well as provision of emission factors for different particle size ranges. This study was aimed at quantifying particle emission factors from four types of wood found in South East Queensland forests: Spotted Gum (Corymbia citriodora), Red Gum (Eucalypt tereticornis), Blood Gum (Eucalypt intermedia), and Iron bark (Eucalypt decorticans); under controlled laboratory conditions. The experimental set up included a modified commercial stove connected to a dilution system designed for the conditions of the study. Measurements of particle number size distribution and concentration resulting from the burning of woods with a relatively homogenous moisture content (in the range of 15 to 26 %) and for different rates of burning were performed using a TSI Scanning Mobility Particle Sizer (SMPS) in the size range from 10 to 600 nm and a TSI Dust Trak for PM2.5. The results of the study in terms of the relationship between particle number size distribution and different condition of burning for different species show that particle number emission factors and PM2.5 mass emission factors depend on the type of wood and the burning rate; fast burning or slow burning. The average particle number emission factors for fast burning conditions are in the range of 3.3 x 1015 to 5.7 x 1015 particles/kg, and for PM2.5 are in the range of 139 to 217 mg/kg.

Built environment education and research : making connections

This conference is a landmark gathering of those from around the world concerned with the future of Built environment education and Research. It takes place at a time of great change and opportunity. Around the world the long-standing principles of what, how and who we teach for graduate entry into Built environment professions, is increasingly under review. The need for research and the way in which it is funded, conducted and knowledge shared is also under increasing pressure. Both changes are being triggered by a fast changing and increasingly challenging competitive environment for education and research. Competition for the highest quality of graduate entrants in the right numbers is becoming more intense. Competition between Universities, as funding for education and research comes under ever close scrutiny, is intensifying and we are all being forced to look for more effective and exciting ways of recruting, retaining, enhancing and maximising the achievement of our students and of our staff in their research activities. Competition amongst employees in industry is becoming more intense as professional employers increasingly recognise that people and knowledge are their key strategic resources. Universities are increasingly looking to partnerships with industry, the professions and other Universities to further improve their eduacation, research and innovation activities. These challenges are unfolding at a time of accelerating development in information technologies and systems and in our understanding of principles of knowledge management and pedagogical advancement. This environment presents both opportunities and threats to the world of education.

Being There

This 60 minute work looked to challenge traditional expectations of how dancers ‘perform’ and what it means when they are ‘themselves’ onstage. The audience was asked to sit in an ellipse on stage and the dancers were often performing quite close to them. While the audience didn’t move once the work began, the proximity to the dancers allowed them an unusual opportunity to see these dancers deconstructing their own profession and their own world of performance in an intimate environment. This was done for, and with the audience, and for some, it connected them deeply with the performers. For Georg Simmel, an early 20th Century sociologist, ‘the eye of a person discloses his own soul when he seeks to uncover that of another. What occurs in this direct mutual reciprocity is the entire field of human relationships.’ Performer authenticity, while utilised often in film and theatre, is not common in the form of dance. Because of our societal tendency toward the desire for authenticity, and its uncommon usage in dance, an inversion of this convention is one of the many tools that is available to choreographers to form deep connections with their audience and is one that is gaining popularity throughout the world as a form of connection via reality and the immediacy of live performance.

The city, self, and connections : transyouth and urban social networking in Seoul

The end of the Korean War in 1953 marked the beginning of Seoul’s transformation from the shattered capital city of South Korea to one of the most connected, populous, and fast-changing hubs of global economy. Seoul’s technosocial development has been celebrated nationally and internationally. To the outside, young Koreans’ swift and extensive adoption and adaptation to digital technologies has been a subject of exotification; to adults in Korea, it has been a subject of criticism (see Yoon in this volume). With the understanding that ‘the city is connections,’ it is crucial to study not only the macro-level design of the city as a network (through policy, for example), but also its micro-level construction at the intersection of people, place, and technology. Accordingly, this chapter explores this exact intersection to comprehensively portray the constant renewal of the city as imagined and experienced by young Koreans. The chapter is based on fieldwork conducted in Seoul, South Korea, from 2007 to 2008 as part of a research project on the mobile play culture of Seoul transyouth, the transitional demographic situated between youth and adulthood, and the pioneers of the Korean ‘broadband miracle’ (Hazlett, 2004). The study draws upon transdisciplinary research data including interviews, questionnaires, diaries, and Shared Visual Ethnography (SVE) to render the everyday urban social networking of young Seoulites with and through which they interact to constantly (re)create the city and the self.

The city is connections : Seoul as an urban network

With the rise of ubiquitous computing in recent years, concepts of spatiality have become a significant topic of discussion in design and development of multimedia systems. This article investigates spatial practices at the intersection of youth, technology, and urban space in Seoul, and examines what the author calls ‘transyouth’: in the South Korean context, these people are between the ages of 18 and 24, situated on the delicate border between digital natives and immigrants in Prensky’s (2001) terms. In the first section, the article sets out the technosocial environment of contemporary Seoul. This is followed by a discussion of social networking processes derived from semi-structured interviews conducted in 2007-8 with Seoul transyouth about their ‘lived experiences of the city.’ Interviewees reported how they interact to play, work, and live with and within the city’s unique environment. The article develops a theme of how technosocial convergence (re)creates urban environments and argues for a need to consider such user-driven spatial recreation in designing cities as (ubiquitous) urban networks in recognition of its changing technosocial contours of connections. This is explored in three spaces of different scales: Cyworld as an online social networking space; cocoon housing – a form of individual residential space which is growing rapidly in many Korean cities – as a private living space; and u-City (ubiquitous City) as the future macro-space of Seoul.

Teachers making connections : online communities as a source of professional learning

The impact of the Internet on our lives has been pervasive. People are increasingly turning to the social interaction available on the Internet to satisfy their needs, whether these are professional or personal. The Internet offers users fast access to social contacts such as online chat groups and discussion lists,helping us to make connections with others. Online communities are being increasingly used by teachers for professional support, guidance and inspiration. These are often organised around subject areas and offer teachers opportunities to develop both personally and professionally. Online communities may present as a source of continuous professional development for teachers as they are able to deliver authentic and personalised opportunities for learning. This paper will present the findings of a study that was conducted on three online communities for teachers. It will explore the nature of online community membership and offer some conclusions regarding their potential as a source of professional learning for teachers.