Determination of particle concentration in the breathing zone for four different types of office ventilation systems

Many factors affect the airflow patterns, thermal comfort, contaminant removal efficiency and indoor air quality at individual workstations in office buildings. In this study, four ventilation systems were used in a test chamber designed to represent an area of a typical office building floor and reproduce the real characteristics of a modern office space. Measurements of particle concentration and thermal parameters (temperature and velocity) were carried out for each of the following types of ventilation systems: a) conventional air distribution system with ceiling supply and return; b) conventional air distribution system with ceiling supply and return near the floor; c) underfloor air distribution system; and d) split system. The measurements aimed to analyse the particle removal efficiency in the breathing zone and the impact of particle concentration on an individual at the workstation. The efficiency of the ventilation system was analysed by measuring particle size and concentration, ventilation effectiveness and the Indoor/Outdoor ratio. Each ventilation system showed different airflow patterns and the efficiency of each ventilation system in the removal of the particles in the breathing zone showed no correlation with particle size and the various methods of analyses used.

National practices in investment decision making in road sector

This document provides the findings of a national review of investment decision-making practices in road asset management. Efforts were concentrated on identifying the strategic objectives of agencies in road asset management, establishing and understanding criteria different organisations adopted and ascertaining the exact methodologies used by different sate road authorities. The investment objectives of Australian road authorities are based on triple-bottom line considerations (social, environmental, economic and political). In some cases, comparing with some social considerations, such as regional economic development, equity, and access to pubic service etc., Benefit-Cost Ratio has limited influence on the decision-making. Australian road authorities have developed various decision support tools. Although Multi-Criteria Analysis has been preliminarily used in case by case study, pavement management systems, which are primarily based on Benefit Cost Analysis, are still the main decision support tool. This situation is not compatible with the triple-bottom line objectives. There is need to fill the gap between decision support tools and decision-making itself. Different decision criteria should be adopted based on the contents of the work. Additional decision criteria, which are able to address social, environmental and political impacts, are needed to develop or identify. Environmental issue plays a more and more important role in decision-making. However, the criteria and respective weights in decision-making process are yet to be clearly identified. Social and political impacts resulted from road infrastructure investment can be identified through Community Perceptions Survey. With accumulative data, prediction models, which are similar as pavement performance models, can be established. Using these models, the decision-makers are able to foresee the social and political consequences of investment alternatives.

User friendly guide for rehabilitation or strengthening of bridge structures using fiber reinforced polymer composites

A worldwide interest is being generated in the use of fibre reinforced polymer composites (FRP) in rehabilitation of reinforced concrete structures. As a replacement for the traditional steel plates or external post-tensioning in strengthening applications, various types of FRP plates, with their high strength to weight ratio and good resistance to corrosion, represent a class of ideal material in external retrofitting. Within the last ten years, many design guidelines have been published to provide guidance for the selection, design and installation of FRP systems for external strengthening of concrete structures. Use of these guidelines requires understanding of a number of issues pertaining to different properties and structural failure modes specific to these materials. A research initiative funded by the CRC for Construction Innovation was undertaken (primarily at RMIT) to develop a decision support tool and a user friendly guide for use of fibre reinforced polymer composites in rehabilitation of concrete structures. The user guidelines presented in this report were developed after industry consultation and a comprehensive review of the state of the art technology. The scope of the guide was mainly developed based on outcomes of two workshops with Queensland Department of Main Roads (QDMR). The document covers material properties, recommended construction requirements, design philosophy, flexural, shear and torsional strengthening of beams and strengthening of columns. In developing this document, the guidelines published on FIB Bulletin 14 (2002), Task group 9.3, International Federation of Structural Concrete (FIB) and American Concrete Institute Committee 440 report (2002) were consulted in conjunction with provisions of the Austroads Bridge design code (1992) and Australian Concrete Structures code AS3600 (2002). In conclusion, the user guide presents design examples covering typical strengthening scenarios.

Nonfatal heroin overdoses in Queensland, Australia : an analysis of ambulance data

In the past decade, the utilization of ambulance data to inform the prevalence of nonfatal heroin overdose has increased. These data can assist public health policymakers, law enforcement agencies, and health providers in planning and allocating resources. This study examined the 672 ambulance attendances at nonfatal heroin overdoses in Queensland, Australia, in 2000. Gender distribution showed a typical 70/30 male-to-female ratio. An equal number of persons with nonfatal heroin overdose were between 15 and 24 years of age and 25 and 34 years of age. Police were present in only 1 of 6 cases, and 28.1% of patients reported using drugs alone. Ambulance data are proving to be a valuable population-based resource for describing the incidence and characteristics of nonfatal heroin overdose episodes. Future studies could focus on the differences between nonfatal heroin overdose and fatal heroin overdose samples.

Identifying programs to reduce road trauma to A.C.T. motorcyclists

A broad range of motorcycle safety programs and systems exist in Australia and New Zealand. These vary from statewide licensing and training systems run by government licensing and transport agencies to safety programs run in small communities and by individual rider groups. While the effectiveness of licensing and training has been reviewed and recommendations for improvement have been developed (e.g. Haworth & Mulvihill, 2005), little is known about many smaller or innovative programs, and their potential to improve motorcycle safety in the ACT.

Synthesis and Raman spectroscopic study of Mg/Al,Fe hydrotalcites with variable cationic ratios

Hydrotalcites of formula Mg6 (Fe,Al)2(OH)16(CO3).4H2O formed by intercalation with the carbonate anion as a function of divalent/trivalent cationic ratio have been successfully synthesised. The XRD patterns show variation in the d-spacing attributed to the size of the cation. Raman and infrared bands in the OH stretching region are assigned to (a) brucite layer OH stretching vibrations (b) water stretching bands and (c) water strongly hydrogen bonded to the carbonate anion. Multiple (CO3)2- symmetric stretching bands suggest that different types of (CO3)2- exist in the hydrotalcite interlayer. Increasing the cation ratio (Mg/Al,Fe) resulted in an increase in the combined intensity of the 2 Raman bands at around 3600 cm-1, attributed to Mg-OH stretching modes, and a shift of the overall band profile to higher wavenumbers. These observations are believed to be a result of the increase in magnesium in the structure. Raman spectroscopy shows a reduction in the symmetry of the carbonate, leading to the conclusion that the anions are bonded to the brucite-like hydroxyl surface and to the water in the interlayer. Water bending modes are identified in the infrared spectra at positions greater than 1630 cm-1, indicating the water is strongly hydrogen bonded to both the interlayer anions and the brucite-like surface.