Impact of opening geometry on the Indoor Environmental Quality in deep, open-plan, naturally ventilated office typologies in temperate climates

Natural ventilation is one means of enriching internal environmental quality (IEQ) whilst reducing the energy consumption of buildings. In an attempt to increase productivity, offices are often deep and open-plan. The typically large energy demands of this type of building indicates the potential to ascertain significant energy savings and a reduction in carbon dioxide (CO2) emissions. Through careful design, the forces associated with natural ventilation can be harnessed and utilised. These small forces mean opening geometry and building form can determine the internal natural airflow patterns, potentially creating unexpected flow characteristics. In these cases, this could lead to a naturally ventilated space overheating, exposing the occupants to thermal discomfort and, in such events, the supply of fresh air may also be reduced. With respect to an energy conscious environment, some leading architectural firms are beginning to explore the use of high-aspect-ratio (HAR) facade openings to improve the IEQ of these spaces. In addition to this, architects are encouraged by client briefs to design deep, open-plan offices without the typical central core; this being a vital element in any multi-storey building, comprising vertical circulation, services, toilets and lifts. To assist in the ventilation of these spaces, they are often broken-up by impressive atrium/atria. Research suggests, the design of facade openings, atrium and building core may influence the performance of the proposed natural ventilation strategy. The thorough examination of innovative design solutions should address these uncertainties and avoid them where possible. However, there is a lack of detailed evidence and guidance is needed to increase design confidence and the utilisation of optimal office design. To better understand natural ventilation, computer and physical airflow modelling, such as computational fluid dynamics (CFD) and water-bath modelling (WBM) are used. The use of multiple techniques not only allows the opportunity to validate the results from each, but also increases the amount of highly detailed data in various formats. Nevertheless, such physical models are often under-utilised, difficult to construct and operate, and expensive. The investigation of the ventilation performance of HAR openings in a generic office environment was carried out using computational models and a novel WBM. Overall ventilation performance was obtained through the installation of the variants of opening geometries into several office configurations with differing core and atrium designs. The utilisation of multiple validated models improved the examination of ventilation performance, thus, providing reliable results to compliment those from the main body of the study. The parametric study was formed of many CFD cases, enabling the juxtaposition of the ventilation performance of all office configurations. The transient nature of WBM and spatial detail of CFD gave the ability to scrutinize issues associated with IEQ; air velocity and thermal stratification and distribution, mean room air temperatures and ventilation flow rates. Therefore, the acknowledgement of the optimal office design allowed the better performing design variants to be highlighted in terms of ventilation performance, also providing a greater understanding of how the design of the space affects IEQ. To start, an archetypal building, which would be subjected to the alternative design parameters, was established. The WBM's form, enabled multiple experiments to be performed by a relatively cheap and easy to run and maintain WBM, thus, increasing the rigour of the validation process and resultant design guidance. A comparison of the results from both modelling techniques showed them to be working correctly, as errors concerning validation metrics were deemed negligible. Results from the WBM experiments and CFD simulations suggested the supply flow from high-level horizontal (HLH) openings brought warm, potentially stale air down into the occupied zones. Conversely, the flow from mid-level vertical (MLV) openings was shown by the CFD to assist in the formation and lowering of thermal stratification. Nonetheless, significant improvements in ventilation flow rates and cooler air temperatures were possible. Moreover, the ventilation performance of this opening design was independent of the means of air removal. Additional enhancements were achieved by a transition from a typical to a perimeter core, as the prevalence of unventilated areas and excessive air velocities was reduced. Nevertheless, when specific variants of atrium design were employed into the perimeter core cases, further performance improvements were perceived. The conditions pervading the now open floor plate, were shown to be enhanced by an atrium design closely replicating the building's footprint. It could be said, the optimal core location is on the perimeter furthest away from the atrium. This configuration, when used in combination with MLV fa\c cade openings, was shown to form the best performing. Substantial advancements have been proposed in the physical modelling procedure of natural ventilation. Further understanding has also been obtained from the results produced, which formed the foundation of the design guidance. The inclusion of these modelling modifications and evidenced guidance throughout the design stage will alleviate performance uncertainties, making the undertaking of naturally ventilated building projects more attractive, simultaneously enhancing the IEQ of low-energy offices.</div

Reviving a language

With half of the world's languages likely to die out this century, a Canadian initiative shows how multimedia technology can regenerate interes

Raviver une langue

Alors que la moitié des langues sont appelées à disparaître au cours de ce siècle, une initiative canadienne les remet au goût du jour grâce au multimédi

Community Hospitals in Selected High Income Countries: A Scoping Review of Approaches and Models.

BACKGROUND: There is no single definition of a community hospital in the UK, despite its long history. We sought to understand the nature and scope of service provision in community hospitals, within the UK and other high-income countries. METHODS: We undertook a scoping review of literature on community hospitals published from 2005 to 2014. Data were extracted on features of the hospital model and the services provided, with results presented as a narrative synthesis. RESULTS: 75 studies were included from ten countries. Community hospitals provide a wide range of services, with wide diversity of provision appearing to reflect local needs. Community hospitals are staffed by a mixture of general practitioners (GPs), nurses, allied health professionals and healthcare assistants. We found many examples of collaborative working arrangements between community hospitals and other health care organisations, including colocation of services, shared workforce with primary care and close collaboration with acute specialists. CONCLUSIONS: Community hospitals are able to provide a diverse range of services, responding to geographical and health system contexts. Their collaborative nature may be particularly important in the design of future models of care delivery, where emphasis is placed on integration of care with a key focus on patient-centred care.This project was funded by the National Institute for Health Research Health Services and Delivery Research programme (project number 12/177/14)

Community hospitals and their services in the NHS: identifying transferable learning from international developments – scoping review, systematic review, country reports and case studies

Background The notion of a community hospital in England is evolving from the traditional model of a local hospital staffed by general practitioners and nurses and serving mainly rural populations. Along with the diversification of models, there is a renewed policy interest in community hospitals and their potential to deliver integrated care. However, there is a need to better understand the role of different models of community hospitals within the wider health economy and an opportunity to learn from experiences of other countries to inform this potential. Objectives This study sought to (1) define the nature and scope of service provision models that fit under the umbrella term ‘community hospital’ in the UK and other high-income countries, (2) analyse evidence of their effectiveness and efficiency, (3) explore the wider role and impact of community engagement in community hospitals, (4) understand how models in other countries operate and asses their role within the wider health-care system, and (5) identify the potential for community hospitals to perform an integrative role in the delivery of health and social care. Methods A multimethod study including a scoping review of community hospital models, a linked systematic review of their effectiveness and efficiency, an analysis of experiences in Australia, Finland, Italy, Norway and Scotland, and case studies of four community hospitals in Finland, Italy and Scotland. Results The evidence reviews found that community hospitals provide a diverse range of services, spanning primary, secondary and long-term care in geographical and health system contexts. They can offer an effective and efficient alternative to acute hospitals. Patient experience was frequently reported to be better at community hospitals, and the cost-effectiveness of some models was found to be similar to that of general hospitals, although evidence was limited. Evidence from other countries showed that community hospitals provide a wide spectrum of health services that lie on a continuum between serving a ‘geographic purpose’ and having a specific population focus, mainly older people. Structures continue to evolve as countries embark on major reforms to integrate health and social care. Case studies highlighted that it is important to consider local and national contexts when looking at how to transfer models across settings, how to overcome barriers to integration beyond location and how the community should be best represented. Limitations The use of a restricted definition may have excluded some relevant community hospital models, and the small number of countries and case studies included for comparison may limit the transferability of findings for England. Although this research provides detailed insights into community hospitals in five countries, it was not in its scope to include the perspective of patients in any depth. Conclusions At a time when emphasis is being placed on integrated and community-based care, community hospitals have the potential to assume a more strategic role in health-care delivery locally, providing care closer to people’s homes. There is a need for more research into the effectiveness and cost-effectiveness of community hospitals, the role of the community and optimal staff profile(s). Funding The National Institute for Health Research Health Services and Delivery Research programme

A multidisciplinary consensus on dehydration: definitions, diagnostic methods and clinical implications

Background: Dehydration appears prevalent, costly and associated with adverse outcomes. We sought to generate consensus on such key issues and elucidate need for further scientific enquiry. Materials and Methods: A modified Delphi process combined expert opinion and evidence appraisal. 12 relevant experts addressed dehydration’s definition, objective markers and impact on physiology and outcome. Results: Fifteen consensus statements and seven research recommendations were generated. Key findings, evidenced in detail, were that there is no universally-accepted definition for dehydration; hydration assessment is complex and requires combining physiological and laboratory variables; ‘dehydration’ and ‘hypovolaemia’ are incorrectly used interchangeably; abnormal hydration status includes relative and/or absolute abnormalities in body water and serum/plasma osmolality (pOsm); raised pOsm usually indicates dehydration; direct measurement of pOsm is the gold standard for determining dehydration; pOsm >300 and ≤280 mOsm/kg classifies a person as hyper or hypo-osmolar; outside extremes, signs of adult dehydration are subtle and unreliable; dehydration is common in hospitals and care homes and associated with poorer outcomes. Discussion: Dehydration poses risk to public health. Dehydration is under-recognised and poorly managed in hospital and community-based care. Further research is required to improve assessment and management of dehydration and the authors have made recommendations to focus academic endeavours

Tuberculosis control in South African gold mines: mathematical modeling of a trial of community-wide isoniazid preventive therapy.

A recent major cluster randomized trial of screening, active disease treatment, and mass isoniazid preventive therapy for 9 months during 2006-2011 among South African gold miners showed reduced individual-level tuberculosis incidence but no detectable population-level impact. We fitted a dynamic mathematical model to trial data and explored 1) factors contributing to the lack of population-level impact, 2) the best-achievable impact if all implementation characteristics were increased to the highest level achieved during the trial ("optimized intervention"), and 3) how tuberculosis might be better controlled with additional interventions (improving diagnostics, reducing treatment delay, providing isoniazid preventive therapy continuously to human immunodeficiency virus-positive people, or scaling up antiretroviral treatment coverage) individually and in combination. We found the following: 1) The model suggests that a small proportion of latent infections among human immunodeficiency virus-positive people were cured, which could have been a key factor explaining the lack of detectable population-level impact. 2) The optimized implementation increased impact by only 10%. 3) Implementing additional interventions individually and in combination led to up to 30% and 75% reductions, respectively, in tuberculosis incidence after 10 years. Tuberculosis control requires a combination prevention approach, including health systems strengthening to minimize treatment delay, improving diagnostics, increased antiretroviral treatment coverage, and effective preventive treatment regimens

A 10Gbps optical burst switching network incorporating ultra-fast (5ns) wavelength switched tunable laser sources

This paper outlines the development of a prototype optical burst mode switching network based upon a star topology, the ultimate application of which could be as a transparent payload processor onboard satellite repeaters. The network architecture incorporates multiple tunable laser sources, burst mode receivers and a passive optical router (Arrayed Waveguide Grating). Each tunable optical signal should carry ≥10Gbps and be capable of wavelength switching in c. 5ns timescales. Two monolithic tunable laser types, based upon different technologies, will be utilised: a Slotted Fabry Perot laser (a Fabry Perot laser with slots added in order to introduce controlled cavity perturbations); and a Modulated Grating Y-Branch Laser (MGY: a widely tunable, multi-section device similar to the DBR laser). While the Slotted Fabry Perot laser is expected to achieve the required switching times, it is an immature technology not yet capable of achieving tunability over 80 ITU channels from a single chip. The MGY device is a more mature technology and has full C-band ITU channel coverage, but is not capable of the required short switching times. Hence, in order to facilitate the integration of this more mature technology into the prototype breadboard with the requisite switching time capabilities, a system of ‘dual laser’ transmitters is being developed to enable data transmission from one MGY laser while the other switches and vice-versa. This work is being performed under ESA contract AO 1-5025/06/NL/PM, Optical Technologies for Ultra - fast Processing