Design of a single ultra-low-loss magnetic ballast for a wide range of T5 high-efficiency fluorescent lamps

A patent-pending single design of an ultralow-loss (ULL) magnetic ballast for T5 high-efficient (T5-HE) fluorescent lamps rated from 14 to 35 W is presented. Based on the use of a nonlinear physical low-pressure discharge lamp model, it is discovered that the same set of ballast parameters can be chosen for operating T5-HE 14-, 21-, 28-, and 35-W lamps at their respective rated power at a mains voltage in the range of 220-240 V. With energy efficiency higher than and lifetime much longer than their electronic counterparts and being recyclable, the ULL ballasts offer a more environmentally friendly solution to T5-HE lamps than electronic ballasts. This single-ballast design offers great convenience to both ballast manufacturers and users, because only one product design can cover a range of the most popular T5-HE lamps. Both theoretical analysis and experimental results are included to confirm the validity of the proposal. © 2011 IEEE.published_or_final_versio

Recurrent abdominal pain in paediatric patients

Recurrent abdominal pain is a common problem in the paediatric population. While functional abdominal pain accounts for the majority of cases, an organic cause for pain may be found in about 5% to 10% of children. Diagnostic evaluation depends on the clinical presentation and the presence of specific findings. Excessive testing should be avoided as this may increase parental anxiety and put the child through unnecessary stress.published_or_final_versio

Probabilistic optimal sizing of stand-alone PV systems with modeling of variable solar radiation and load demand

PSPI Committee Main/Planning for Integration of Renewable Resources, DGs, and EVs into the Electric Grid (combo): presentation no. 2012GM0675This paper presents a comprehensive sizing methodology which could contain all key elements necessary to obtain a practical sizing result for a stand-alone photovoltaic (PV) system. First, a stochastic solar radiation model based on limited/incomplete local weather data is formulated to synthesis various chronological solar radiation patterns. This enables us to evaluate a long-term system performance and characterize any extreme weather conditions. Second, a stochastic load simulator is developed to simulate realistic load patterns. Third, two reliability indices, Expected-Energy-Not-Supplied (EENS) and Expected-Excessive-Energy-Supplied (EEES), are incorporated with an Annualized Cost of System (ACS) to form a new objective function called an Annualized Reliability and Cost of System (ARCS) for optimization. We then apply a particle swarm optimization (PSO) algorithm to obtain the optimum system configuration for a given acceptable risk level. An actual case study is conducted to demonstrate the feasibility and applicability of the proposed methodology. © 2012 IEEE.published_or_final_versionThe 2012 IEEE Power and Energy Society General Meeting, San Diego, CA., 22-26 July 2012. In IEEE Power and Energy Society General Meeting Proceedings, 2012, p. 1-

A nano-view of West Nile virus-induced cellular changes during infection

BACKGROUND: Microscopic imaging of viruses and their interactions with and effects on host cells are frequently held back by limitations of the microscope's resolution or the invasive nature of the sample preparation procedures. It is also difficult to have a technique that would allow simultaneous imaging of both surface and sub-surface on the same cell. This has hampered endeavours to elucidate virus-host interactions. Atomic Force Microscopy (AFM), which is commonly used in the physical sciences, is now becoming a good correlative form of microscopy used to complement existing optical, confocal and electron microscopy for biological applications RESULTS: In this study, the West Nile (Sarafend) virus-infected Vero cell model was used. The atomic force microscope was found to be useful in producing high resolution images of virus-host events with minimal sample processing requirements. The AFM was able to image the budding of the West Nile (Sarafend) virus at the infected cell surface. Proliferation of the filopodia and thickening of clusters of actin filaments accompanied West Nile virus replication. CONCLUSIONS: The study shows that the AFM is useful for virus-host interaction studies. The technique provides morphological information on both the virus and the host cell during the infection stages

A "Class-A2" ultra-low-loss magnetic ballast for T5 fluorescent lamps - A new trend for sustainable lighting technology

The high-voltage and low-current features of T5 lamps imply that the copper and core losses of the magnetic ballast can be greatly reduced. This paper shows that magnetic ballasts for high-voltage T5 lamps are not only feasible but their luminous and ballast-loss performance can be better than those of the electronic ballasts. Contrary to common belief, high frequency operation of T5 28 W lamps increases the luminous efficacy by an average of 3.6% only (less than 5%). Practical implementation of an ultra-low-loss magnetic ballast system for T5 28 W lamps is presented. Its total system power is less than the 32 W upper limit specified for Class A2 of energy-efficient electronic ballast for T5 28 W lamps. High-luminous efficacy of 75.63-77.66 lm/W can be achieved. This important breakthrough has the potential of reversing the existing trend of using electronic ballasts as the energy-saving technology in lighting industry. With a better luminous efficacy, lower product and maintenance costs, much longer lifetime, and the use of recyclable metallic materials over its electronic counterparts, this patent-pending proposal provides a truly sustainable lighting solution to the lighting industry. © 2006 IEEE.published_or_final_versio

Skin banking in Hong Kong - the development and experience in Queen Mary Hospital

published_or_final_versio

A "Class-A2" ultra-low-loss magnetic ballast for T5 fluorescent lamps - A new trend for sustainable lighting technology

The high-voltage and low-current features of T5 lamps imply that the copper and core losses of the magnetic ballast can be greatly reduced. This paper shows that magnetic ballasts for high-voltage T5 lamps are not only feasible but their luminous and ballast-loss performance can be better than those of the electronic ballasts. Contrary to common belief, high frequency operation of T5 28 W lamps increases the luminous efficacy by an average of 3.6% only (less than 5%). Practical implementation of an ultra-low-loss magnetic ballast system for T5 28 W lamps is presented. Its total system power is less than the 32 W upper limit specified for Class A2 of energy-efficient electronic ballast for T5 28 W lamps. High-luminous efficacy of 75.63-77.66 lm/W can be achieved. This important breakthrough has the potential of reversing the existing trend of using electronic ballasts as the energy-saving technology in lighting industry. With a better luminous efficacy, lower product and maintenance costs, much longer lifetime, and the use of recyclable metallic materials over its electronic counterparts, this patent-pending proposal provides a truly sustainable lighting solution to the lighting industry. © 2006 IEEE.published_or_final_versio

Candidates registered for reasonable adjustments underperform compared to other candidates in the national undergraduate Prescribing Safety Assessment: Retrospective cohort analysis (2014-2018).

AIMS: Candidates with disabilities are eligible for reasonable adjustments (RA) while undertaking the national Prescribing Safety Assessment (PSA). The PSA is a novel open-book, time-constrained, multiformat assessment that may pose challenges to candidates with dyslexia and other disabilities. METHODS: Retrospective cohort analysis of 36 140 UK candidates undertaking first-sitting of the PSA (2014-2018). RESULTS: Of the 36 140 candidates, 9.1% (3284) were registered for RA. The RA group had lower pass rates (absolute difference 1.94%, 95% confidence interval 1.01-2.87%; P < .001) and assessment scores (1.16 percentage marks, 95% confidence interval 0.83-1.48; P < .001) compared with the non-RA group. This absolute difference is small relative to overall variability. This difference persists after adjusting for confounding factors (medical school and paper), and was present for all 8 different question types. The attainment gap within each medical school is negatively correlated with the school's overall performance, both in terms of pass rate (P < .001) and scores (P = .01). The RA group were also less likely to perceive the PSA as an appropriate test, having easy to follow layout/presentation or clear/unambiguous questions, even after adjusting for candidate performance. CONCLUSION: This analysis identifies slight differences in academic performance of candidates requiring RA in a national undergraduate assessment. The study is limited by the unavailability of data on ethnicity, sex, age, diagnosis and time of diagnosis. While further research is required to determine the cause of the attainment gap, this study emphasises the need to maintain a careful review on the fairness and validity of all aspects of the assessment

Use of deltopectoral flap for head and neck reconstruction

Theme: Challenges to specialists in the 21st centurypublished_or_final_versio