123 research outputs found

    Application of Fickian and non-Fickian diffusion models to study moisture diffusion in asphalt mastics

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    The objective of this study was to investigate certain aspects of asphalt mastic moisture diffusion characteristics in order to better understand the moisture damage phenomenon in asphalt mixtures. Moisture sorption experiments were conducted on four asphalt mastics using an environmental chamber capable of automatically controlling both relative humidity (85 %) and temperature (23 °C). The four mastics tested were identical in terms of bitumen type (40/60 pen), bitumen amount (25 % by of wt% total mix), mineral filler amount (25 % by wt%) and fine aggregate amount (50 % by wt%). The materials differed in terms of mineral filler type (granite or limestone) and fine aggregate type (granite or limestone). Preliminary data obtained during the early part of the study showed certain anomalous behavior of the materials including geometry (thickness)-dependent diffusion coefficient. It was therefore decided to investigate some aspects related to moisture diffusion in mastics by applying the Fickian and two non-Fickian (anomalous) diffusion models to the moisture sorption data. The two non-Fickian models included a two-phase Langmuir-type model and a two-parameter time-variable model. All three models predicted moisture diffusion in mastics extremely well (R 2 > 0.95). The observed variation of diffusion coefficient with thickness was attributed in part to microstructural changes (settlement of the denser fine aggregates near the bottom of the material) during the rather long-duration diffusion testing. This assertion was supported by X-ray computed tomography imaging of the mastic that showed significant accumulation of aggregate particles near the bottom of the sample with time. The results from the Langmuir-type model support a two-phase (free and bound) model for moisture absorbed by asphalt mastic and suggests about 80 % of absorbed water in the free phase remain bound within the mastic. The results also suggest that moisture diffusion in asphalt mastic may be time-dependent with diffusion decreasing by about four times during a typical diffusion test lasting up to 500 h. The study concludes that both geometry and time-dependent physical characteristics of mastic are important factors to consider with respect to moisture diffusion in asphalt mastics

    Moisture-induced strength degradation of aggregate–asphalt mastic bonds

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    A common manifestation of moisture-induced damage in asphalt mixtures is the loss of adhesion at the aggregate–asphalt mastic interface and/or cohesion within the bulk mastic. This paper investigates the effects of moisture on the aggregate–mastic interfacial adhesive strength as well as the bulk mastic cohesive strength. Physical adsorption concepts were used to characterise the thermodynamic work of adhesion and debonding of the aggregate–mastic bonds using dynamic vapour sorption and contact angle measurements. Moisture diffusion in the aggregate substrates and in the bulk mastics was determined using gravimetric techniques. Mineral composition of the aggregates was characterised by a technique based on the combination of a scanning electron microscope and multiple energy dispersive X-ray detectors. Aggregate–mastic bond strength was determined using moisture-conditioned butt-jointed tensile test specimens, while mastic cohesive strength was determined using dog bone-shaped tensile specimens. Aggregate–mastic bonds comprising granite mastics performed worse in terms of moisture resistance than limestone mastic bonds. The effect of moisture on the aggregate–mastic interfacial bond appears to be more detrimental than the effect of moisture on the bulk mastic

    Managing COVID-19 within and across health systems:why we need performance intelligence to coordinate a global response

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    Background The COVID-19 pandemic is a complex global public health crisis presenting clinical, organisational and system-wide challenges. Different research perspectives on health are needed in order to manage and monitor this crisis. Performance intelligence is an approach that emphasises the need for different research perspectives in supporting health systems’ decision-makers to determine policies based on well-informed choices. In this paper, we present the viewpoint of the Innovative Training Network for Healthcare Performance Intelligence Professionals (HealthPros) on how performance intelligence can be used during and after the COVID-19 pandemic. Discussion A lack of standardised information, paired with limited discussion and alignment between countries contribute to uncertainty in decision-making in all countries. Consequently, a plethora of different non-data-driven and uncoordinated approaches to address the outbreak are noted worldwide. Comparative health system research is needed to help countries shape their response models in social care, public health, primary care, hospital care and long-term care through the different phases of the pandemic. There is a need in each phase to compare context-specific bundles of measures where the impact on health outcomes can be modelled using targeted data and advanced statistical methods. Performance intelligence can be pursued to compare data, construct indicators and identify optimal strategies. Embracing a system perspective will allow countries to take coordinated strategic decisions while mitigating the risk of system collapse.A framework for the development and implementation of performance intelligence has been outlined by the HealthPros Network and is of pertinence. Health systems need better and more timely data to govern through a pandemic-induced transition period where tensions between care needs, demand and capacity are exceptionally high worldwide. Health systems are challenged to ensure essential levels of healthcare towards all patients, including those who need routine assistance. Conclusion Performance intelligence plays an essential role as part of a broader public health strategy in guiding the decisions of health system actors on the implementation of contextualised measures to tackle COVID-19 or any future epidemic as well as their effect on the health system at large. This should be based on commonly agreed-upon standardised data and fit-for-purpose indicators, making optimal use of existing health information infrastructures. The HealthPros Network can make a meaningful contribution

    Involvement of patients or their representatives in quality management functions in EU hospitals:implementation and impact on patient-centred care strategies

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    OBJECTIVE: The objective of this study was to describe the involvement of patients or their representatives in quality management (QM) functions and to assess associations between levels of involvement and the implementation of patient-centred care strategies. DESIGN: A cross-sectional, multilevel STUDY DESIGN: that surveyed quality managers and department heads and data from an organizational audit. SETTING: Randomly selected hospitals (n = 74) from seven European countries (The Czech Republic, France, Germany, Poland, Portugal, Spain and Turkey). PARTICIPANTS: Hospital quality managers (n = 74) and heads of clinical departments (n = 262) in charge of four patient pathways (acute myocardial infarction, stroke, hip fracture and deliveries) participated in the data collection between May 2011 and February 2012. MAIN OUTCOME MEASURES: Four items reflecting essential patient-centred care strategies based on an on-site hospital visit: (1) formal survey seeking views of patients and carers, (2) written policies on patients' rights, (3) patient information literature including guidelines and (4) fact sheets for post-discharge care. The main predictors were patient involvement in QM at the (i) hospital level and (ii) pathway level. RESULTS: Current levels of involving patients and their representatives in QM functions in European hospitals are low at hospital level (mean score 1.6 on a scale of 0 to 5, SD 0.7), but even lower at departmental level (mean 0.6, SD 0.7). We did not detect associations between levels of involving patients and their representatives in QM functions and the implementation of patient-centred care strategies; however, the smallest hospitals were more likely to have implemented patient-centred care strategies. CONCLUSIONS: There is insufficient evidence that involving patients and their representatives in QM leads to establishing or implementing strategies and procedures that facilitate patient-centred care; however, lack of evidence should not be interpreted as evidence of no effect

    Clinical leadership through commissioning: Does it work in practice?

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    In tune with much international practice, the English National Health Service has been striving to transform health care provision to make it more affordable in the face of rising demand. At the heart of a set of recent radical reforms has been the launch of ‘clinical commissioning’ using the vehicle of local groups of General Practitioners (GPs). This devolves a large portion of the total healthcare budget to these groups. National government policy statements make clear that the expectation is that the groups will ‘transform’ the organization and provision of health services. In this article we draw upon interviews, observations and analysis of internal documents to make an assessment of the extent to which clinical leaders have seized the opportunity presented by the creation of these groups to attempt transformative service redesign

    Lessons on the COVID-19 pandemic, for and by primary care professionals worldwide.

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    The COVID-19 pandemic has modified organisation and processes of primary care. In this paper, we aim to summarise experiences of international primary care systems. We explored personal accounts and findings in reporting on the early experiences from primary care during the pandemic, through the online Global Forum on Universal Health Coverage and Primary Health Care. During the early stage of the pandemic, primary care continued as the first point of contact to the health system but was poorly informed by policy makers on how to fulfil its role and ill equipped to provide care while protecting staff and patients against further spread of the infection. In many countries, the creativity and initiatives of local health professionals led to the introduction or extension of the use of telephone, e-mail and virtual consulting, and introduced triaging to separate 'suspected' COVID-19 from non-COVID-19 care. There were substantial concerns of collateral damage to the health of the population due to abandoned or postponed routine care. The pandemic presents important lessons to strengthen health systems through better connection between public health, primary care, and secondary care to cope better with future waves of this and other pandemics

    Development and validation of an index to assess hospital quality management systems

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    The study, "Deepening our Understanding of Quality Improvement in Europe (DUQuE)" has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 241822. Funding to pay the Open Access publication charges for this article was provided by European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 241822.Objective: The aim of this study was to develop and validate an index to assess the implementation of quality management systems (QMSs) in European countries. Design: Questionnaire development was facilitated through expert opinion, literature review and earlier empirical research. A cross-sectional online survey utilizing the questionnaire was undertaken between May 2011 and February 2012. We used psychometric methods to explore the factor structure, reliability and validity of the instrument. Setting and participants. As part of the Deepening our Understanding of Quality improvement in Europe (DUQuE) project, we invited a random sample of 188 hospitals in 7 countries. The quality managers of these hospitals were the main respondents. Main Outcome Measure. The extent of implementation of QMSs. Results: Factor analysis yielded nine scales, which were combined to build the Quality Management Systems Index. Cronbach's reliability coefficients were satisfactory (ranging from 0.72 to 0.82) for eight scales and low for one scale (0.48). Corrected item-total correlations provided adequate evidence of factor homogeneity. Inter-scale correlations showed that every factor was related, but also distinct, and added to the index. Construct validity testing showed that the index was related to recent measures of quality. Participating hospitals attained a mean value of 19.7 (standard deviation of 4.7) on the index that theoretically ranged from 0 to 27. Conclusion: Assessing QMSs across Europe has the potential to help policy-makers and other stakeholders to compare hospitals and focus on the most important areas for improvement
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