30 resultados para Radiation-use efficiency


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Many tertiary institutions in Australia provide support to develop online teaching and learning resources, an environment characterised by demands from students for quality face-to-face and distance education, staff concern over workloads, institutional budgeting constraints and an imperative to use management systems. There also remains a legitimate focus on using online learning to facilitate new learning strategies within a complex social setting. This paper presents an extended instructional design model in which the development cycle for online teaching and learning materials uses a scaffolding strategy in order to cater for learner-centred activities and to maximise scarce developer and academic resources. The model also integrates accepted phases of the instructional development process to provide guidelines for the disposition of staff and to more accurately reflect the creation of resources as learning design rather than instructional design.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Daylight is an essential contextual ingredient of place making. Research in daylighting has recently received major attention for its valuable contribution to the sustainability of the built environment. Previous research has investigated the role of daylighting in energy efficiency, its regional qualities in relation to the façade configuration, and its contribution to the sense of visual comfort. This paper argues that appropriate use of daylighting will ensure not only visual and thermal comfort in an urban setting, but also contributes to the place identity and hence sustainability of urban regeneration projects. The paper identifies the daylight variables that affect the success of the regeneration of heritage sites in Eastern Mediterranean. Daylight variables in public open spaces include a combination of sunlight, skylight and the reflected light from the facades and the ground. The Solar altitude, the geometry of sectional profiles, the reflectance of the opposing facades, the width of the street and the density of the urban built environment are examined to simulate the daylight performance in the selected heritage sites. Located in the historical Darb al-Ahmar district, Aslam Square is selected as part of one of the rehabilitation project in Cairo. This paper examines the photometric and morphological properties of the existing configuration using daylight simulation software. Various spherical projections were developed to represent full 3D visual environment. The paper calculates and analyses the direct radiation energy, the sky diffused energy and the reflected energy in the case study.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The use of electricity in buildings constitutes around 16% of Singapore's energy demand. In view of the fact that Singapore is an urban city with no rural base, which depends heavily on air-conditioning to cool its buildings all year round, the survival as a nation depends on its ability to excel economically. To incorporate energy efficiency measures is one of the key missions to ensure that the economy is sustainable. The recently launched building energy efficiency labelling programme is such an initiative. Buildings whose energy performance are among the nation's top 25% and maintain a healthy and productive indoor environment as well as uphold a minimum performance for different systems can qualify to attain the Energy Smart Office Label. Detailed methodologies of the labelling process as well as the performance standards are elaborated. The main strengths of this system namely a rigorous benchmarking database and an independent audit conducted by a private accredited Energy Service Company (ESCO) are highlighted. A few buildings were awarded the Energy Smart Office Label during the launching of the programme conducted in December 2005. The labeling of other types of buildings like hotels, schools, hospitals, etc. is ongoing.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective To examine whether students use or avoid newly shaded areas created by shade sails installed at schools.

Design Cluster randomised controlled trial with secondary schools as the unit of randomisation.

Setting 51 secondary schools with limited available shade, in Australia, assessed over two spring and summer terms.

Participants Students outside at lunch times.

Intervention Purpose built shade sails were installed in winter 2005 at full sun study sites to increase available shade for students in the school grounds.

Main outcome measure Mean number of students using the primary study sites during weekly observations at lunch time.

Results Over the study period the mean change in students using the primary study site from pre-test to post-test was 2.63 (95% confidence interval 0.87 to 4.39) students in intervention schools and –0.03 (–1.16 to 1.09) students in control schools. The difference in mean change between groups was 2.67 (0.65 to 4.68) students (P=0.011).

Conclusions
Students used rather than avoided newly shaded areas provided by purpose built shade sails at secondary schools in this trial, suggesting a practical means of reducing adolescents’ exposure to ultraviolet radiation.

Trial registration Exempt.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Disease caused by the soilborne plant pathogen Phytophthora cinnamomi causes long-term floristic and structural changes in native vegetation communities in Australia. Key components of the management of this disease are to know where it occurs and the rate at which it spreads. The distribution of P. cinnamomi has generally been assessed as locality points of infestation and mapping the extent of diseased vegetation in any area is difficult and costly. This study was undertaken in P. cinnamomi-infested heathland communities in southern Victoria, Australia, where the symptoms of P. cinnamomi arise as a mosaic within healthy vegetation. We investigated the potential to improve the efficiency and effectiveness of mapping and monitoring vegetation affected by P. cinnamomi using digital multi-spectral imaging. This technique was developed for the purposes of monitoring vegetation and provides a single, seamless ortho-rectified digital image over the total area of interest. It is used to spatially quantify small differences in the characteristics of vegetation. In this study, the symptoms of disease caused by P. cinnamomi infestation were related to differences in the imagery and were used to map areas of infestation. Comparison of the digital multi-spectral imaging indications with on-ground observations gave moderate accuracy between the datasets (κ = 0.49) for disease and healthy indications. This study demonstrates the ability of the technique to determine disease extent over broad areas in native vegetation and provides a non-invasive, cost effective tool for management.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background : Efficiency and equity are both important policy objectives in resource allocation. The discipline of health economics has traditionally focused on maximising efficiency, however addressing inequities in health also requires consideration. Methods to incorporate equity within economic evaluation techniques range from qualitative judgements to quantitative outcomes-based equity weights. Yet, due to definitional uncertainties and other inherent limitations, no method has been universally adopted to date. This paper proposes an alternative cost-based equity weight for use in the economic evaluation of interventions delivered from primary health care services.

Methods :
Equity is defined in terms of 'access' to health services, with the vertical equity objective to achieve 'equitable access for unequal need'. Using the Australian Indigenous population as an illustrative case study, the magnitude of the equity weight is constructed using the ratio of the costs of providing specific interventions via Indigenous primary health care services compared with the costs of the same interventions delivered via mainstream services. Applying this weight to the costs of subsequent interventions deflates the costs of provision via Indigenous health services, and thus makes comparisons with mainstream more equitable when applied during economic evaluation.

Results :
Based on achieving 'equitable access', existing measures of health inequity are suitable for establishing 'need', however the magnitude of health inequity is not necessarily proportional to the magnitude of resources required to redress it. Rather, equitable access may be better measured using appropriate methods of health service delivery for the target group. 'Equity of access' also suggests a focus on the processes of providing equitable health care rather than on outcomes, and therefore supports application of equity weights to the cost side rather than the outcomes side of the economic equation.

Conclusion : Cost-based weights have the potential to provide a pragmatic method of equity weight construction which is both understandable to policy makers and sensitive to the needs of target groups. It could improve the evidence base for resource allocation decisions, and be generalised to other disadvantaged groups who share similar concepts of equity. Development of this decision-making tool represents a potentially important avenue for further health economics research.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The ultrafiltration of whey solutions is a common feature of dairy processes. However, the frequent fouling of ultrafiltration membranes and the subsequent cleaning cycle significantly affect the economics of such a process. In this work, we investigated the effect of ultrasonics on the cleaning of whey-fouled membranes and examined the variables that influence this effect. Experiments were conducted using a small single sheet membrane unit that was immersed totally within an ultrasonic bath.

Results show that the use of ultrasonics enhances the flux recovery following fouling. The extent of flux recovery is independent of the length of sonication time and increases with ultrasonic power. The use of surfactants in combination with ultrasonic irradiation shows a synergistic effect, providing a better efficiency than either cleaning process alone. Repetitive use of ultrasonic cleaning over a 1 month period does not result in any significant change in the permeate flux of a cleaned membrane, indicating that the ultrasonic treatment does not appear to damage the membrane structure itself.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

New Zealand is one of the world’s largest producers of dairy products and has a climate with high levels of solar radiation; however, the use of solar energy in the dairy processing industry has received limited attention. An examination of historical records found that the annual peak in New Zealand milk production and processing occurs at a time when solar radiation levels are increasing markedly. An F-Chart analysis was used to simulate the performance of large-area arrays of solar collectors and to determine their suitability for heating and cooling in a dairy processing environment. For the study four types of solar collectors were analysed: glazed flat plates, evacuated tubes, evacuated tubes with CPC reflectors and a building-integrated solar collector under development at the University of Waikato (UoW). It was found that of these echnologies, both flat plate and evacuated tubes with CPC reflectors could make useful heating and cooling contributions. Furthermore, the solar fraction was determined mainly by the collector area to storage volume ratio. Finally, it was found that the UoW building-integrated solar collector could make a significant contribution to energy use in dairies and may be an attractive future technology for the industry.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Oral diseases including dental caries and periodontal disease are among the most prevalent and costly diseases in Australia today. Around 5.4% of Australia’s health dollar is spent on dental services totalling around $2.6 billion, 84% of which are delivered through the private sector (AIHW 2001). The other 16% is spent providing public sector services in varied and inadequate ways. While disease rates among school children have declined significantly in the past 20 years the gains made among children are not flowing on to adult dentitions and our aging population will place increasing demands on an inadequate system into the future (AHMAC 2001). Around 50% of adults do not received regular care and this has implications for widening health inequalities as the greatest burden falls on lower income groups (AIHW DSRU 2001). The National Competition Policy agenda has initiated, Australia-wide, reviews of dental legislation applying to delivery of services by dentists, dental specialists, dental therapists and hygienists and dental technicians and prosthetists. The review of the Victorian Dentists Act 1972, was completed first in 1999, followed by the other Australian states with Queensland, the ACT and the Northern Territory still developing legislation. One of the objectives of the new Victorian Act is to ‘…promote access to dental care’. This study has grown out of the need to know more about how dental therapists and hygienists might be utilised to achieve this and the legislative frameworks that could enable such roles. This study used qualitative methods to explore dental health policy making associated with strategies that may increase access to dental care using dental therapists and hygienists. The study used a multiple case study design to critically examine the dental policy development process around the Review of the Dentists Act 1972 in Victoria; to assess legislative and regulatory dental policy reforms in other states in Australia and to conduct a comparative analysis of dental health policy as it relates to dental auxiliary practice internationally. Data collection has involved (I) semi-structured interviews with key participants and stakeholders in the policy development processes in Victoria, interstate and overseas, and (ii) analysis of documentary data sources. The study has taken a grounded theory approach whereby theoretical issues that emerged from the Victorian case study were further developed and challenged in the subsequent interstate and international case studies. A component of this study has required the development of indicators in regulatory models for dental hygienists and therapists that will increase access to dental care for the community. These indicators have been used to analyse regulation reform and the likely impacts in each setting. Despite evidence of need, evidence of the effectiveness and efficiency of dental therapists and hygienists, and the National Competition Policy agenda of increasing efficiency, the legislation reviews have mostly produces only minor changes. Results show that almost all Australian states have regulated dental therapists and hygienists in more prescriptive ways than they do dentists. The study has found that dental policy making is still dominated by the views of private practice dentists under elitist models that largely protect dentist authority, autonomy and sovereignty. The influence of dentist professional dominance has meant that governments have been reluctant to make sweeping changes. The study has demonstrated alternative models of regulation for dental therapists and hygienists, which would allow wider utilisation of their skills, more effective use of public sector funding, increased access to services and a grater focus on preventive care. In the light of theses outcomes, there is a need to continue to advocate for changes that will increase the public health focus of oral health care.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Hemodialysis is only infrequently used in drug overdosage situations. The efficacy of hemodialysis to remove the drug depends upon the pharmacokinetics and pharmacodynamics of the drug. At normal therapeutic concentrations, valproic acid is predominantly protein bound and therefore removal by hemodialysis is limited. In an overdose situation, protein binding is rapidly saturated and therefore the substantially larger quantities of the free drug can rapidly cause toxicity. Slow low-efficient daily diafiltration (SLEDD) has not previously been utilized in a drug overdose situation. We report the effective use of SLEDD to remove high toxic concentrations of valproic acid in an overdose situation. Slow low-efficient daily diafiltration also prevented the rebound phenomenon that can occur as the excess drug is released from its protein-bound stores. Hybrid dialysis therapies deserve further evaluation in the management of other poisonings where extra-corporeal therapy is indicated.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND
The Better Outcomes in Mental Health Care (BOMHC) initiative encourages general practitioners to use electronic mental health resources (EMHRs) during consultation with patients requiring psychological assistance. However, there is little data on GPs’ acceptance and use of EMHRs.

METHOD
Semistructured interviews were conducted with 27 GPs to determine their attitude toward EMHRs, and their use during consultation with patients.

RESULTS
Few GPs reported frequently using EMHRs in consultation. Identified barriers to use included lack of familiarity with information technology, and insufficient knowledge of available resources. Identified advantages of electronic resources included high patient acceptance, time efficiency, and improved quality of information.

DISCUSSION
General practitioners recognise several advantages of utilising electronic resources for managing patients with mental illness. However, GPs are not sufficiently familiar with electronic resources to use them effectively. This could be overcome by education.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We report for the first time an in situ photopolymerization of model co-monomers, 2-hydroxyethyl methacrylate (HEMA) and tetra (ethylene glycol) diacrylate (TEGDA), in an IL electrolyte containing I2 for DSSCs. TiO2 nanoparticles were used as the photo-initiator and co-gelator in a charge transfer polymerization reaction. The gel-IL polymer obtained was characterized in terms of the diffusion properties of the electrolyte. Preliminary results from DSSCs assembled using the gel-IL electrolyte showed energy conversion efficiency of 3.9% at 1 sun (AM1.5) and 5.0% at 0.39 sun illumination.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Cold start driving cycles exhibit an increase in friction losses due to the low temperatures of metal and media compared to normal operating engine conditions. These friction losses are responsible for up to 10% penalty in fuel economy over the official drive cycles like the New European Drive Cycle (NEDC), where the temperature of the oil even at the end of the 1180 s of the drive cycle is below the fully warmed up values of between 100°C and 120°C. At engine oil temperatures below 100°C the water from the blow by condensates and dilutes the engine oil in the oil pan which negatively affects engine wear. Therefore engine oil temperatures above 100°C are desirable to minimize engine wear through blow by condensate. The paper presents a new technique to warm up the engine oil that significantly reduces the friction losses and therefore also reduces the fuel economy penalty during a 22°C cold start NEDC. Chassis dynamometer experiments demonstrated fuel economy improvements of over 7% as well as significant emission reductions by rapidly increasing the oil temperature. Oil temperatures were increased by up to 60°C during certain parts of the NEDC. It is shown how a very simple sensitivity analysis can be used to assess the relative size or efficiency of different heat transfer passes and the resulting fuel economy improvement potential of different heat recovery systems system. Due to its simplicity the method is very fast to use and therefore also very cost effective. The method demonstrated a very good correlation for the fuel consumption within ±1% compared to measurements on a vehicle chassis roll.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Human populations can cause serious damage to the natural environment. This, however, depends on the type of society and its size. Many traditional communities have a balanced relation with the environment, using practices for managing the soil, water and natural resources in order to satisfy their needs that are compatible to the general goals of environmental preservation.

The most usual approach to environmental conservation in the world sees human beings as intruders, potentially destroyers of the nature and, as a consequence, generally requires local population to be expelled from the protected regions. This situation has generated social conflicts because many protected areas, particularly in developing countries, are inhabited by indigenous or other traditional communities.

The disagreement about expelling or maintaining traditional communities in environmental conservation areas is strengthened by the lack of diagnostics on which changes are produced or suffered by communities in the region where they live. This paper presents a methodology developed to analyse land use dynamics in region with environmental conservation and traditional communities. We seek a better understanding of the way traditional communities use their space, the spatial pattern of land uses, which factors drive land use change, which impacts can be seen in those regions and identify the effects of conservation policies on land use dynamics.

The application of the method to the National Park of Superagui, Brazil, has successfully performed characterisation, analysis and simulation of land use dynamics in a region of environmental importance. Testing different scenarios has suggested that the adoption of a less restrictive policy for environmental conservation would have resulted in less social conflict with the same environmental efficiency than the established current policy.