981 resultados para Failure investigation
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QUT's Centre for Subtropical Design (CSD) partnered with a major developer to bring together some of Brisbane’s most experienced and creative architects and designers in a two-day intensive design charrette to propose innovative design strategies for naturally-ventilated high rise residential buildings. An inner-urban renewal site in Queensland’s capital city Brisbane gave four multi-disciplinary teams the opportunity to address a raft of issues that developers and consultants will confront more and more in the future in warm humid climates. The quest to release apartment dwellers from dependence on energy-hungry air-conditioning and artificial lighting was central to the design brief for the towers. Mentored by Richard Hassell of WOHA, the creative teams focussed on climate-responsive design principles for passive climate control including orientation, cross-ventilation and outdoor living in order to reduce greenhouse gas emissions and offset occupants’ rising energy costs. This article discusses how outcomes of the charrette take their cue from the city’s subtropical climate and demonstrate how high-density high-rise living can be attractive, affordable and sustainable through positive engagement with the subtropical climate’s natural attributes.
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Water uptake refers to the ability of atmospheric particles to take up water vapour from the surrounding atmosphere. This is an important property that affects particle size and phase and therefore influences many characteristics of aerosols relevant to air quality and climate. However, the water uptake properties of many important atmospheric aerosol systems, including those related to the oceans, are still not fully understood. Therefore, the primary aim of this PhD research program was to investigate the water uptake properties of marine aerosols. In particular, the effect of organics on marine aerosol water uptake was investigated. Field campaigns were conducted at remote coastal sites on the east coast of Australia (Agnes Water; March-April 2007) and west coast of Ireland (Mace Head; June 2007), and laboratory measurements were performed on bubble-generated sea spray aerosols. A combined Volatility-Hygroscopicity-Tandem Differential Mobility Analyser (VH-TDMA) was employed in all experiments. This system probes the changes in the hygroscopic properties of nanoparticles as volatile organic components are progressively evaporated. It also allows particle composition to be inferred from combined volatility-hygroscopicity measurements. Frequent new particle formation and growth events were observed during the Agnes Water campaign. The VH-TDMA was used to investigate freshly nucleated particles (17-22.5 nm) and it was found that the condensation of sulphate and/or organic vapours was responsible for driving particle growth during the events. Aitken mode particles (~40 nm) were also measured with the VH-TDMA. In 3 out of 18 VH-TDMA scans evaporation of a volatile, organic component caused a very large increase in hygroscopicity that could only be explained by an increase in the absolute water uptake of the particle residuals, and not merely an increase in their relative hygroscopicity. This indicated the presence of organic components that were suppressing the hygroscopic growth of mixed particles on the timescale of humidification in the VH-TDMA (6.5 secs). It was suggested that the suppression of water uptake was caused by either a reduced rate of hygroscopic growth due to the presence of organic films, or organic-inorganic interactions in solution droplets that had a negative effect on hygroscopicity. Mixed organic-inorganic particles were rarely observed by the VH-TDMA during the summer campaign conducted at Mace Head. The majority of particles below 100 nm in clean, marine air appeared to be sulphates neutralised to varying degrees by ammonia. On one unique day, 26 June 2007, particularly large concentrations of sulphate aerosol were observed and identified as volcanic emissions from Iceland. The degree of neutralisation of the sulphate aerosol by ammonia was calculated by the VH-TDMA and found to compare well with the same quantity measured by an aerosol mass spectrometer. This was an important verification of the VH-TMDA‘s ability to identify ammoniated sulphate aerosols based on the simultaneous measurement of aerosol volatility and hygroscopicity. A series of measurements were also conducted on sea spray aerosols generated from Moreton Bay seawater samples in a laboratory-based bubble chamber. Accumulation mode sea spray particles (38-173 nm) were found to contain only a minor organic fraction (< 10%) that had little effect on particle hygroscopicity. These results are important because previous studies have observed that accumulation mode sea spray particles are predominantly organic (~80% organic mass fraction). The work presented here suggests that this is not always the case, and that there may be currently unknown factors that are controlling the transfer of organics to the aerosol phase during the bubble bursting process. Taken together, the results of this research program have significantly improved our understanding of organic-containing marine aerosols and the way they interact with water vapour in the atmosphere.
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The purpose of this paper is to understand how teachers’ identity as an assessor in a standards-referenced assessment system may be developed through their participation in online social moderation meetings. In these meetings teachers negotiate and share their understandings of assessment standards and judgement decisions. In particular, the paper focuses on the relationship between the technology, the moderation processes and teachers’ development in this assessment system. This paper draws on sociocultural theories of learning to analyse the qualitative data collected through observations of eleven online moderation meetings and interviews of the teachers involved in these meetings. The results provide insights into the mediating role of the technology with regard to teachers’ development of shared meanings and common practices within a standards-referenced assessment system.
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Aim: Increased car dependency amongst Australia's ageing population may result in increased social isolation and other health impacts associated with the cessation of driving. While public transport represents an alternative to car usage, patronage remains low amongst senior cohorts. This study investigates the facilitators and barriers to public transport patronage and the nature of car dependence among older Australians. Method: Data was gathered from a sample of 24 adults (mean = 70.33 years) through a combination of quantitative (remote behavioural observation) and qualitative (interviews) investigation. Results: Findings suggest factors of relative convenience, affordability and health/mobility dictate choices of transport mode. The car is considered more convenient for the majority of suburban trips irrespective of the availability of public transport. Conclusion: Policy attention should focus on providing better education and information regarding driving cessation and addressing aged-specific social aspects of public transport including the accommodation of various health and mobility issues.
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Atmospheric concentration of total suspended particulate matter (TSP) and associated heavy metals are a great concern due to their adverse health impacts and contribution to stormwater pollution. This paper discusses the outcomes of a study which investigated the variation of atmospheric TSP and heavy metal concentrations with traffic and land use characteristics during weekdays and weekends. Data for this study was gathered from fifteen sites at the Gold Coast, Australia using a high volume air sampler. The study detected consistently high TSP concentrations during weekdays compared to weekends. This confirms the significant influence of traffic related sources on TSP loads during weekdays. Both traffic and land use related sources equally contribute to TSP during weekends. Almost all the measured heavy metals showed high concentration on weekdays compared to weekends indicating significant contributions from traffic related emissions. Among the heavy metals, Zn concentration was the highest followed by Pb. It is postulated that re-suspension of previously deposited reserves was the main Pb source. Soil related sources were the main contributors of Mn.
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We read the excellent review of telemonitoring in chronic heart failure (CHF)1 with interest and commend the authors on the proposed classification of telemedical remote management systems according to the type of data transfer, decision ability and level of integration. However, several points require clarification in relation to our Cochrane review of telemonitoring and structured telephone support2. We included a study by Kielblock3. We corresponded directly with this study team specifically to find out whether or not this was a randomised study and were informed that it was a randomised trial, albeit by date of birth. We note in our review2 that this randomisation method carries a high risk of bias. Post-hoc metaanalyses without these data demonstrate no substantial change to the effect estimates for all cause mortality (original risk ratio (RR) 0·66 [95% CI 0·54, 0·81], p<0·0001; revised RR 0·72 [95% CI 0·57, 0·92], p=0·008), all-cause hospitalisation (original RR 0·91 [95% CI 0·84, 0·99] p=0·02; revised RR 0.92 [95% CI 0·84, 1·02], p=0·10 ) or CHF-related hospitalisation (original RR 0·79 [95% CI 0·67, 0·94] p=0·008; revised RR 0·75 [95% CI 0·60, 0·94] p=0·01). Secondly, we would classify the Tele-HF study4, 5 as structured telephone support, rather than telemonitoring. Again, inclusion of these data alters the point-estimate but not the overall result of the meta-analyses4. Finally, our review2 does not include invasive telemonitoring as the search strategy was not designed to capture these studies. Therefore direct comparison of our review findings with recent studies of these interventions is not recommended.
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Letter to the Editor of New England Journal of Medicine on behalf of the Cochrane Systematic Review team.
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Australian, Iranian and Portuguese university students (N = 967) completed University Students Depression Inventory (USDI; Khawaja & Bryden, 2006) in English, Persian, and Portuguese languages respectively. A series of MANOVA were used to examine differences in depression symptoms as an effect of the country and demographic variables. Interactions were also examined. The results indicated that country, gender, and year level had some impact on the depressive symptoms of the university students. Australian students were more depressed than the Iranian and Portuguese students, while Iranian students were more depressed than the Portuguese students. Subscales of USDI: Lethargy, Motivation, and Cognitive/Emotional were also used to compare the depressive symptoms of students. The Australian female students reported a significantly higher level of lethargy than their male counterparts. Similarly, the first year male students from Iran were significantly more lethargic than the first year Iranian female students. Iranian and Portuguese male students, compared to the female students of these countries, experienced a lower level of motivation. The Australian and Iranian students, compared to the Portuguese students, reported a significantly higher level of cognitive and affective symptoms. The scores on the Cognitive/Emotional subscale increased with the year level. Differences among students’ depression are described and implications discussed.
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Objective: To determine whether remote monitoring (structured telephone support or telemonitoring) without regular clinic or home visits improves outcomes for patients with chronic heart failure. Data sources: 15 electronic databases, hand searches of previous studies, and contact with authors and experts. Data extraction: Two investigators independently screened the results. Review methods: Published randomised controlled trials comparing remote monitoring programmes with usual care in patients with chronic heart failure managed within the community. Results: 14 randomised controlled trials (4264 patients) of remote monitoring met the inclusion criteria: four evaluated telemonitoring, nine evaluated structured telephone support, and one evaluated both. Remote monitoring programmes reduced the rates of admission to hospital for chronic heart failure by 21% (95% confidence interval 11% to 31%) and all cause mortality by 20% (8% to 31%); of the six trials evaluating health related quality of life three reported significant benefits with remote monitoring, and of the four studies examining healthcare costs with structured telephone support three reported reduced cost and one no effect. Conclusion: Programmes for chronic heart failure that include remote monitoring have a positive effect on clinical outcomes in community dwelling patients with chronic heart failure.
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Background: Although the potential to reduce hospitalisation and mortality in chronic heart failure (CHF) is well reported, the feasibility of receiving healthcare by structured telephone support or telemonitoring is not. Aims: To determine; adherence, adaptation and acceptability to a national nurse-coordinated telephone-monitoring CHF management strategy. The Chronic Heart Failure Assistance by Telephone Study (CHAT). Methods: Triangulation of descriptive statistics, feedback surveys and qualitative analysis of clinical notes. Cohort comprised of standard care plus intervention (SC + I) participants who completed the first year of the study. Results: 30 GPs (70% rural) randomised to SC + I recruited 79 eligible participants, of whom 60 (76%) completed the full 12 month follow-up period. During this time 3619 calls were made into the CHAT system (mean 45.81 SD ± 79.26, range 0-369), Overall there was an adherence to the study protocol of 65.8% (95% CI 0.54-0.75; p = 0.001) however, of the 60 participants who completed the 12 month follow-up period the adherence was significantly higher at 92.3% (95% CI 0.82-0.97, p ≤ 0.001). Only 3% of this elderly group (mean age 74.7 ±9.3 years) were unable to learn or competently use the technology. Participants rated CHAT with a total acceptability rate of 76.45%. Conclusion: This study shows that elderly CHF patients can adapt quickly, find telephone-monitoring an acceptable part of their healthcare routine, and are able to maintain good adherence for a least 12 months. © 2007.
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To the Editor: Chaudhry et al. suggest that enhanced support in the use of a telephone-based interactive voice-response system for patients recently discharged after worsening heart failure does not improve outcomes. This finding is broadly consistent with previous systematic reviews of telephone support1 and contrasts with the substantial effect observed with home telemonitoring of vital signs in similar populations.1 The treatment of patients in the control group was excellent, but unrepresentative of usual clinical care and not inferior to the treatment of patients receiving enhanced support. Monitoring alone is unlikely to improve outcomes but may do so when it improves prescription of or adherence to lifesaving treatments. Given enough resources, traditional methods for delivering care may render an interactive voice-response system or a home telemonitoring system ineffective. Nonetheless, there may be more cost-efficient approaches to ensuring quality care.2 Informal post hoc addition of these data to our recent meta-analysis of telephone support1 does not substantially alter the point estimates for death from any cause or heart-failure−related hospitalizations, but it does nullify the small benefit in hospitalizations for any cause, which may not be reduced by a heart-failure−focused intervention.1 Original article: Telemonitoring in Patients with Heart Failure NEJM. December 9, 2010 | S.I. Chaudhry and Others
An experimental and computational investigation of performance of Green Gully for reusing stormwater
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A new stormwater quality improvement device (SQID) called ‘Green Gully’ has been designed and developed in this study with an aim to re-using stormwater for irrigating plants and trees. The main purpose of the Green Gully is to collect road runoff/stormwater, make it suitable for irrigation and provide an automated network system for watering roadside plants and irrigational areas. This paper presents the design and development of Green Gully along with experimental and computational investigations of the performance of Green Gully. Performance (in the form of efficiency, i.e. the percentage of water flow through the gully grate) was experimentally determined using a gully model in the laboratory first, then a three dimensional numerical model was developed and simulated to predict the efficiency of Green Gully as a function of flow rate. Computational Fluid Dynamics (CFD) code FLUENT was used for the simulation. GAMBIT was used for geometry creation and mesh generation. Experimental and simulation results are discussed and compared in this paper. The predicted efficiency was compared with the laboratory measured efficiency. It was found that the simulated results are in good agreement with the experimental results.
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National Housing Relics and Scenic Sites (NHRSSs) in China are the equivalent of National Parks in the West but have contrasting features and broader roles when compared to their Western counterparts. By reviewing and analysing more than 370 academic sources, this paper identifies 6 major issue clusters and future challenges that will influence the management of NHRSSs over time. It also provides a number of cases to illustrate the particular features of NHRSSs. Identifying the hot issues and important challenges in Chinese NHRSSs will provide valuable insights into priorities now being discussed in highly populated areas of the World.