Novel D²T control for single-switch dual-output switching power converters

Author name used in this publication: C. K. TseAuthor name used in this publication: S. C. WongAuthor name used in this publication: K. C. TamRefereed conference paper2003-2004 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

An improved wavelet approach for finding steady-state waveforms of power electronics circuits using discrete convolution

Author name used in this publication: Chi K. TseAuthor name used in this publication: Kam C. Tam2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Spurious modulation on current-mode controlled dc/dc converters : an explanation for intermittent chaotic operation

Author name used in this publication: S. C. WongAuthor name used in this publication: C. K. TseAuthor name used in this publication: K. C. TamRefereed conference paper2003-2004 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Fast analytical approach to finding steady-state waveforms for power electronics circuits using orthogonal polynomial basis functions

Author name used in this publication: K. C. TamAuthor name used in this publication: S. C. WongAuthor name used in this publication: C. K. TseRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Primitive neuroectodermal adrenal gland tumour

Ewing's sarcoma, also called primitive neuroectodermal tumour of the adrenal gland, is extremely rare. Only a few cases have been reported in the literature. We report on a woman with adult-onset primitive neuroectodermal tumour of the adrenal gland presenting with progressive flank pain. Computed tomography confirmed an adrenal tumour with invasion of the left diaphragm and kidney. Radical surgery was performed and the pain completely resolved; histology confirmed the presence of primitive neuroectodermal tumour, for which she was given chemotherapy. The clinical presentation of this condition is non-specific, and a definitive diagnosis is based on a combination of histology, as well as immunohistochemical and cytogenic analysis. According to the literature, these tumours demonstrate rapid growth and aggressive behaviour but there are no well-established guidelines or treatment strategies. Nevertheless, surgery remains the mainstay of local disease control; curative surgery can be performed in most patients. Adjuvant chemoirradiation has been advocated yet no consensus is available. The prognosis of patients with primitive neuroectodermal tumours remains poor.published_or_final_versio

Mild iodine deficiency and thyroid disorders in Hong Kong.

OBJECTIVES: To review evidence of iodine deficiency and clinical thyroid disorders in Hong Kong. DATA SOURCES: Publications on local dietary iodine intake, the iodine content of local food items, and clinical thyroid problems in the Hong Kong population. DATA EXTRACTION: Data was extracted and evaluated independently by the authors. DATA SYNTHESIS: Iodine is an essential nutrient. Iodine deficiency can lead to goitre, hypothyroidism, mental deficiency, and impaired growth. It is now appreciated that determination of goitre incidence in children alone may grossly underestimate the problem of iodine deficiency in a population. In total, the evidence indicates that iodine deficiency exists in Hong Kong, leading to clinical problems of transient neonatal hypothyroidism, goitrogenesis, and thyroid disorders in pregnant women and neonates, as well as thyroid dysfunction in the elderly. CONCLUSION: A supplementation programme aimed at a relatively uniform iodine intake is recommended to avoid deficient or excessive iodine intake in subpopulations.published_or_final_versio

Serum lipid and apolipoprotein distributions in Hong Kong Chinese

STUDY OBJECTIVE--The aim was to describe the distribution of lipids and apolipoproteins in the Chinese population in Hong Kong. DESIGN--This was a prospective, cross sectional, population based survey. SETTINGS--The study was conducted in a single, self referred, out patient screening centre. PARTICIPANTS--Altogether 825 Chinese adults aged > or = 20 years were screened. One hundred subjects who had previously had lipid measurement and 29 who were taking lipid modifying drugs were excluded but 289 men and 407 women remained for further analysis. MAIN RESULTS--Age standardised mean (SEM) lipids concentrations for Hong Kong Chinese were total cholesterol: men, 5.48 (0.05) mmol/l and women, 5.46 (0.06) mmol/l; triglycerides: men, 1.22 (1.03) mmol/l and women, 1.00 (1.03) mmol/l; high density lipoprotein (HDL) cholesterol: men, 1.25 (0.02) mmol/l and women, 1.42 (0.02) mmol/l; low density lipoprotein (LDL) cholesterol: men, 3.56 (0.05) mmol/l and women, 3.50 (0.06) mmol/l; apolipoprotein A-I (apo A-I): men, 1.34 (0.01) g/l and women, 1.46 (0.01) g/l; and apolipoprotein B (apo B): men, 1.15 (0.02) g/l and women, 1.06 (0.02) g/l. The total to HDL cholesterol ratios were men, 4.62 (0.07) and women, 4.10 (0.08); and apo B to apo A-I ratios (apo B/A) were men, 0.88 (0.02) and women, 0.75 (0.02). While levels of total cholesterol, LDL cholesterol, apo B, triglycerides, total/HDL cholesterol, and apo B/A were positively associated with age in both sexes and were higher in men before the age 50-59 years, they rose steeply thereafter in women to cross over the levels in men. In contrast, HDL cholesterol decreased with age while apo A-I remained constant, and both were consistently higher in women than in men in all age groups. CONCLUSIONS--Hong Kong Chinese have attained lipid profiles similar to those in other developed western populations. Environmental factors seem influential in this regard. Faced with the increasing coronary mortality of recent years, there should be a major effort to reduce the cholesterol concentrations in this population.published_or_final_versio

Plasma cholesterol levels and brain development in preterm newborns.

BackgroundTo assess whether postnatal plasma cholesterol levels are associated with microstructural and macrostructural regional brain development in preterm newborns.MethodsSixty preterm newborns (born 24-32 weeks gestational age) were assessed using MRI studies soon after birth and again at term-equivalent age. Blood samples were obtained within 7 days of each MRI scan to analyze for plasma cholesterol and lathosterol (a marker of endogenous cholesterol synthesis) levels. Outcomes were assessed at 3 years using the Bayley Scales of Infant Development, Third Edition.ResultsEarly plasma lathosterol levels were associated with increased axial and radial diffusivities and increased volume of the subcortical white matter. Early plasma cholesterol levels were associated with increased volume of the cerebellum. Early plasma lathosterol levels were associated with a 2-point decrease in motor scores at 3 years.ConclusionsHigher early endogenous cholesterol synthesis is associated with worse microstructural measures and larger volumes in the subcortical white matter that may signify regional edema and worse motor outcomes. Higher early cholesterol is associated with improved cerebellar volumes. Further work is needed to better understand how the balance of cholesterol supply and endogenous synthesis impacts preterm brain development, especially if these may be modifiable factors to improve outcomes

Quality Assessment of Printable Strain Hardening Cementitious Composites Manufactured in Two Different Printing Facilities

Over the past few years, several studies have shown the potential of three-dimensional concrete printing (3DCP) for applications in building and civil engineering. However, only a few studies have compared the properties of the fresh printing material and the quality of the printed elements from different printing facilities. Variations in the manufacturing conditions caused by the mixing procedures, the pumping device and the nozzle shape and/or dimensions may influence the quality of the printed elements. This study investigates the differences in the fresh and hardened properties of a printing material tested in two different printing facilities. The pump pressure and temperature experienced by the printing material during the printing session are monitored real-time. Hardened properties are measured for the printed elements, such as the bending capacity, the apparent density, and the air void content. The research shows that two different printing facilities may result in printed elements with relative differences in flexural strength and volumetric density of 49% and 7%, respectively

Sarah Benson Walker: 1812-1893

Sarah Benson Walker was the daughter of Methodists, Robert and Ann Mather, who joined the Quakers in 1934. That same year Sarah agreed to marry George Washinton Walker, despite once referring to him and James Backhouse as those 'pesky Quakers'. Sarah had ten children and served on Jane's Franklin's visiting committee to the Cascades Female Factory, and regularly participated in Monthly Meetings. Photograph titled Bakery bill for the Walker family, 1883 - is a bill for the Walker family from a Liverpool Street Bakery (held by University of Tasmania Library, Special and Rare Materials Collections). Biographical Text Source: Quaker Life in Tasmania: The First Hundred Years. Michael Bennett, University of Tasmania Library, 2007, p. 19