Characterization of expiration air jets and droplet size distributions immediately at the mouth opening

Size distributions of expiratory droplets expelled during coughing and speaking and the velocities of the expiration air jets of healthy volunteers were measured. Droplet size was measured using the Interferometric Mie imaging (IMI) technique while the Particle Image Velocimetry (PIV) technique was used for measuring air velocity. These techniques allowed measurements in close proximity to the mouth and avoided air sampling losses. The average expiration air velocity was 11.7 m/s for coughing and 3.9 m/s for speaking. Under the experimental setting, evaporation and condensation effects had negligible impact on the measured droplet size. The geometric mean diameter of droplets from coughing was 13.5m and it was 16.0m for speaking (counting 1 to 100). The estimated total number of droplets expelled ranged from 947 – 2085 per cough and 112 – 6720 for speaking. The estimated droplet concentrations for coughing ranged from 2.4 - 5.2cm-3 per cough and 0.004 – 0.223 cm-3 for speaking.

Size distribution and sites of origin of droplets expelled during expiratory activities

A new Expiratory Droplet Investigation System (EDIS) was used to conduct the most comprehensive program of study to date, of the dilution corrected droplet size distributions produced during different respiratory activities.----- Distinct physiological processes were responsible for specific size distribution modes. The majority of particles for all activities were produced in one or more modes, with diameters below 0.8 µm. That mode occurred during all respiratory activities, including normal breathing. A second mode at 1.8 µm was produced during all activities, but at lower concentrations.----- Speech produced particles in modes near 3.5 µm and 5 µm. The modes became most pronounced during continuous vocalization, suggesting that the aerosolization of secretions lubricating the vocal chords is a major source of droplets in terms of number.----- Non-eqilibrium droplet evaporation was not detectable for particles between 0.5 and 20 μm implying that evaporation to the equilibrium droplet size occurred within 0.8 s.

Cipher cities : effective user interface design for building a digital social network around location-based gaming

In this paper we explore what is required of a User Interface (UI) design in order to encourage participation around playing and creating Location-Based Games (LBGs). To base our research in practice, we present Cipher Cities, a web based system. Through the design of this system, we investigate how UI design can provide tools for complex content creation to compliment and encourage the use of mobile phones for designing, distributing, and playing LBGs. Furthermore we discuss how UI design can promote and support socialisation around LBGs through the design of functional interface components and services such as groups, user profiles, and player status listings.

A multiliteracies project in the middle school : Parents as coteachers

This paper examines the experiences of one middle years’ English and Studies of Society and Environment (SoSE) teacher who adopted a multiliteracies project-based orientation to a unit on War and Refugees. It details the multiliteracies teaching and learning cycle, which is based on four non-hierarchical, pedagogical orientations: situated practice, overt instruction, critical framing and transformed practice (New London Group, 2000; Kalantzis & Cope, 2005a). Following the work of Kalantzis and Cope (2005a), it draws out the knowledge processes exacted in each of these four phases: experiencing the known and the new; conceptualising by naming and theorising; analysing functionally and critically; and, applying appropriately and creatively. Two parents were invited to enter the study as coteachers with the teacher and researcher. Using Bourdieu’s (1992) construct of capital, the findings report on how the multiliteracies approach enabled them to engage in school-based literacy practices differently than they had done previously in classrooms. An unexpected finding concerns the teacher’s altered view about how his role and status were perceived by the parents.

Urban management revolution : intelligent management systems for ubiquitous cities

A successful urban management support system requires an integrated approach. This integration includes bringing together economic, socio-cultural and urban development with a well orchestrated transparent and open decision making mechanism. The paper emphasises the importance of integrated urban management to better tackle the climate change, and to achieve sustainable urban development and sound urban growth management. This paper introduces recent approaches on urban management systems, such as intelligent urban management systems, that are suitable for ubiquitous cities. The paper discusses the essential role of online collaborative decision making in urban and infrastructure planning, development and management, and advocates transparent, fully democratic and participatory mechanisms for an effective urban management system that is particularly suitable for ubiquitous cities. This paper also sheds light on some of the unclear processes of urban management of ubiquitous cities and online collaborative decision making, and reveals the key benefits of integrated and participatory mechanisms in successfully constructing sustainable ubiquitous cities.

The Making of knowledge cities : lessons learned from Melbourne

Knowledge cities are seen as fundamental to the economic growth and development of the 21st century cities. The purpose of this paper is to explore the knowledge city concept in depth. This paper discusses the principles of a knowledge city, and portrays its distinguishing characteristics and processes. The paper relates and analyses Melbourne’s experience as a knowledge city and scrutinises Melbourne’s initiatives on science, technology and innovation and policies for economic and social development. It also illustrates how the city administration played a key role in developing Melbourne as a globally recognised, entrepreneurial and competitive knowledge city. Then this paper identifies key success factors and provides some insights to policy makers of the MENA region cities in designing knowledge cities.

Manufacturing challenges with fabrication of large size mechanical harmonic drives

In truck manufacturing, the exhaust and air inlet pipes are specialized equipment that requires highly skilled, heavy machinery and small batch production methods. This paper describes a project to develop the computer numerically controlled (CNC) pipe bending process for a truck component manufacturer. The company supplies a huge range of heavy duty truck parts to the domestic market and is a significant supplier in Australia. The company has been using traditional methods of machine assisted manual pipe bending techniques. In a drive of continuous improvement, the company has acquired a pre-owned CNC bending machine capable of bending pipes automatically up to 25 bends. However, due to process mismatch, this machine is only used for single bending operation. The researchers studied the bending system and changed the manufacturing process. Using an example exhaust pipe as the benchmark, a significant drop of manufacturing lead time from 70 minutes to 40 minutes for each pipe was demonstrated. There was also a decrease of material cost due to the multiple bends part in one piece without cutting excessive materials for each single bend like it used to be.

Manufacturing challenges with fabrication of large size mechanical harmonic drives

Mechanical harmonic transmissions are relatively new kind of drives having several unusual features. For example, they can provide reduction ratio up to 500:1 in one stage, have very small teeth module compared to conventional drives and very large number of teeth (up to 1000) on a flexible gear. If for conventional drives manufacturing methods are well-developed, fabrication of large size harmonic drives presents a challenge. For example, how to fabricate a thin shell of 1.7m in diameter and wall thickness of 30mm having high precision external teeth at one end and internal splines at the other end? It is so flexible that conventional fabrication methods become unsuitable. In this paper special fabrication methods are discussed that can be used for manufacturing of large size harmonic drive components. They include electro-slag welding and refining, the use of special expandable devices to locate and hold a flexible gear, welding peripheral parts of disks with wear resistant materials with subsequent machining and others. These fabrication methods proved to be effective and harmonic drives built with the use of these innovative technologies have been installed on heavy metallurgical equipment and successfully tested.

The middle years learner

This guide offers a systematic overview of the philosophy, principles, and issues in middle schooling, including contributions from academics and school-based practitioners on intellectual and emotional development in early adolescence, pedagogy, curricula, and the assessment of middle years students.

Middle years teacher education : new programs and research directions

Teacher education programs focussing on the development of specialist teachers for 'the middle years' have proliferated in Australian universities in recent years. This paper provides some insights into middle years' teacher education programs at the University of Queensland, Edith Cowan and Flinders Universities with regard to their: philosophical underpinnings; specific educational context; scope and nature of the program. In addition, some of the research directions and efficacy strategies utilised in conjunction with the programs will be shared, along with some early findings from a longitudinal study in one of the programs. We propose that the pattern of programmatic growth heralds a new time for teacher education, and we speculate about the production of new kinds of teacher identities as graduates take their place in the profession.