Global public health training in the UK: preparing for the future.

BACKGROUND: Many major public health issues today are not confined by national boundaries. However, the global public health workforce appears unprepared to confront the challenges posed by globalization. We therefore sought to investigate whether the current UK public health training programme adequately prepares its graduates to operate in a globalized world. METHODS: We used mixed methods involving an online cross-sectional survey of UK public health trainees on the international content of the Faculty of Public Health's written examination, a qualitative review of the Faculty's 2007 training curriculum and a questionnaire survey of all training deaneries in the UK. RESULTS: We found that global health issues are not addressed by the current training curriculum or in the written examination despite trainee interest for this. Many of the deaneries were also unreceptive to international placements. CONCLUSIONS: Despite the recognized educational legitimacy of global health placements and the favourable UK policy context, the opportunities and international content of public health training remain limited. In order to retain its position as a leader in the field of public health, the UK needs to adapt its training programme to better reflect today's challenges

An Analytic Theory for the Orbits of Circumbinary Planets

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Application potential of ground-coupled heat pumps for multi-storey office buildings in Hong Kong

In this paper, the application potential of ground-coupled heat pumps (GCHP) in a multi-storey office building in Hong Kong was investigated. It was found that within the limited land area occupied by the building, the GCHP could only handle the cooling load for one floor over a range of the ground thermal conductivities and undisturbed ground temperatures. The year-round energy consumption of the GCHP was compared with those using the conventional vapour-compression chiller systems. An energy saving of at least 13.2% and 2.6% could be achieved against those using an air-cooled and a water-cooled vapour-compression chiller with rated coefficients of performance equal to 3.0 and 5.0 respectively.published_or_final_versio

Reduction of Energy Storage Requirements in Future Smart Grid using Electric Springs

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Flexural behaviours of Engineered Cementitious Composites – High strength steel composite beams

Since the compressive strain of normal strength concrete (NSC) (0.23 – 0.3%) is too low to work compatibly with high strength steel (HSS) with typical yield strain greater than 0.35%, Engineered Cementitious Composites (ECC) which generally has a minimum compressive strain of 0.5%, is an attractive alternative to replace NSC when constructing composite beams using HSS sections. This study investigated experimentally the flexural behaviours of composite beams comprising HSS I-section and hybrid Polyethylene-steel fibres (PE-ST) ECC slab. Shear interactions between the HSS beam and the PE-ST ECC slab was provided by normal profiled steel sheeting (PSS) and headed shear studs. Four composite beams including three ECC-HSS beams and one NSC-HSS beam were tested under four-point bending until failure. The test results indicated that while the flexural capacity of ECC-HSS beams only showed a slight improvement, its ductility was significantly enhanced when comparing with the NSC-HSS beam. All ECC-HSS beams failed in a ductile manner and gradual softening behaviours were observed after the peak load. In contrast, the NSC-HSS beam showed a less ductile failure mode with a sudden crushing of NSC and a sharp drop of bending resistance after the peak load. To complement the test results, a 3D nonlinear finite element (FE) model was also developed and validated against the experimental results. Well agreements between the FE and test results were observed. This confirmed that the FE model could be employed to evaluate the general behaviours of ECC-HSS composite beams

A Survey, Classification and Critical Review of Light-Emitting Diode Drivers

Based on a survey on over 1400 commercial LED drivers and a literature review, a range of LED driver topologies are classified according to their applications, power ratings, performance and their energy storage and regulatory requirements. Both passive and active LED drivers are included in the review and their advantages and disadvantages are discussed. This paper also presents an overall view on the technical and cost aspects of the LED technology, which is useful to both researchers and engineers in the lighting industry. Some general guidelines for selecting driver topologies are included to aid design engineers to make appropriate choices.published_or_final_versio

Printed spiral winding inductor with wide frequency bandwidth

Winding parasitic capacitance is a major factor limiting the bandwidth of an inductor. In this paper, 1) the traditional, 2) the alternating, and 3) the partial alternating winding methods are evaluated for the multilayer printed spiral winding inductors for megahertz operations. The self-capacitances of various winding structures are estimated by the summation of parasitic capacitance among the turns of a winding. The electric field energy distributions in the inductors are derived from the voltage profiles to illustrate the relative magnitudes of winding parasitic capacitances. The results show that parasitic capacitance reduction can be achieved by reducing stored electric field energy. The partial alternating winding method is found to have the widest frequency bandwidth with reduced number of through-hole vias for multilayer printed spiral winding design. The theoretical analysis has been confirmed with practical measurements. The results provide useful information for the optimal design of coreless or core-based high-frequency planar magnetics. © 2011 IEEE.published_or_final_versio

A critical review of recent progress in mid-range wireless power transfer

Starting from Tesla’s principles of wireless power transfer a century ago, this critical review outlines recent magneto-inductive research activities on wireless power transfer with the transmission distance greater than the transmitter coil dimension. It summarizes the operating principles of a range of wireless power research into (i) the maximum power transfer and (ii) the maximum energy efficiency principles. The differences and the implications of these two approaches are explained in terms of their energy efficiency and transmission distance capabilities. The differences between the system energy efficiency and the transmission efficiency are also highlighted. The review covers the 2-coil systems, the 4-coil systems, the systems with relay resonators and the wireless domino-resonator systems. Related issues including human exposure issues and reduction of winding resistance are also addressed. The review suggests that the use of the maximum energy efficiency principle in the 2-coil systems is suitable for short-range rather than mid-range applications, the use of the maximum power transfer principle in the 4-coil systems is good for maximizing the transmission distance, but is under a restricted system energy efficiency (< 50%); the use of the maximum energy efficiency principle in relay or domino systems may offer a good compromise for good system energy efficiency and transmission distance on the condition that relay resonators can be placed between the power source and the load.published_or_final_versio

The fifa world cup 2002: The effects of terrorism on sport tourists

This paper discusses the relationship between sport and tourism in reference to a specific hallmark event, the Fédération Internationale de Football Association (FIFA) 2002 Football World Cup. In particular, it investigates the terrorism-related issues that affected the event and the possible implications for future mega sporting events in Australia. It seeks to contribute to awareness of spectator experiences of this event by understanding perceptions of safety and responses to security measures. A questionnaire survey of a convenience-based sample of World Cup spectators in the Republic of Korea was undertaken to determine: the extent to which the terrorist attacks on the United States of America on 11 September, 2001 changed these sport tourists’ motivations to attend the event; how safe they felt in Korea during the World Cup; and how risk management measures taken by the event organizers impacted on the tourists’ level of enjoyment. The findings are discussed in the context of sport event management, concluding with consequences for the future organization of sports events. While this study focused on the impact of an act of terrorism, it is suggested that the implications of other critical incidences with global ramifications, such as the recent war in Iraq and the outbreak of Severe Acute Respiratory Syndrome (SARS) need to be taken into account when planning mega sporting events. © 2003 Taylor & Francis Ltd

A design methodology for smart LED lighting systems powered by weakly regulated renewable power grids

The increasing use of intermittent renewable energy sources to decarbonize electric power generation is expected to introduce dynamic instability to the mains. This situation is of particular concern for mini-grids or isolated grids in which wind and/or solar power sources are the dominant or the sole power sources. In this paper, we utilize the photo-electro-thermal theory to develop a design methodology for LED lighting systems for weakly regulated voltage sources, with the objectives of minimizing the fluctuation of the human luminous perception and adopting reliable LED driver with long lifetime and robustness against extreme weather conditions. The proposed LED system, practically verified in a 10 kVA small power grid driven by an ac voltage source and a wind energy simulator, can be considered as a smart load with its load demand following the power generation. A typical swing of 40 V in the mains will cause only 15% actual light variation in a 132 W LED system when compared with 40% change in 150 W high-pressure-sodium lamp system. The design methodology enables future large-scale LED systems to be designed as a new generation of smart loads that can adapt to the voltage and power fluctuations arising from the intermittent nature of renewable energy sources. © 2011 IEEE.published_or_final_versio