2,837 research outputs found
General study for using LED to replace traditional lighting devices
Author name used in this publication: K. W. E. ChengPower Electronics Research CentreRefereed conference paper2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
The tseung kwan o landfill controversy
AnalysisThis article examines the controversy that arose from the Hong Kong Government's plan to extend the South East New Territories Landfill in Tseung Kwan O into the Clear Water Bay Country Park, particularly how the proposed landfill extension led to a confrontation between the government and the legislature. The authors argue that s 14 of the Country Parks Ordinance (Cap 208) imposes an obligation on the Chief Executive to make an order which he is not free to repeal thereafter. This arrangement comports with the overall statutory scheme and purpose of the legislation which features a four-stage process with provisions for public consultation. The controversy calls into question the efficacy of this four-stage process as well as that of the environmental impact assessment regime. The authors suggest that there is a need to consider strengthening the statutory mechanism for public involvement to prevent a repetition of the present controversy. This article also examines the broader issue of the territory's waste management strategy and the need for more environmentally sustainable policies.published_or_final_versio
New medium teaching method for power electronics
Author name used in this publication: K. W. E. ChengRefereed conference paper2004-2005 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Decellularization of chondrocyte-encapsulated collagen microspheres: A three-dimensional model to study the effects of acellular matrix on stem cell fate
Extracellular matrix (ECM) partially constitutes the stem cell niche. Reconstituting the ECM niche in a three-dimensional (3D) configuration will significantly enhance our understanding of how stem cells interact with and respond to the ECM niche. In this study, we aimed to reconstitute a glycosaminoglycan (GAG)-rich ECM using a microencapsulation technology, produce acellular matrix using a decellularization technique, and investigate the effect of acellular matrix on stem cell fate by repopulating the matrix with human mesenchymal stem cells (hMSCs). We demonstrated that porcine chondrocytes were able to deposit a GAG-rich ECM within the 3D collagen microsphere. All decellularization treatment groups resulted in significant removal of chondrocyte nuclei, but acellular matrix was only achieved using 2% sodium deoxycholate. Nevertheless, decellularization resulted in significant loss in GAG content in almost all treatment groups, and the 2% sodium deoxycholate group was able to preserve about 40% of the GAGs compared with the control group. We further demonstrated that hMSCs seeded onto the decellularized microspheres were able to survive and penetrate into the centre, while hMSCs seeded in the acellular matrix showed positive immunostaining against sox9, indicating that they may be differentiating toward the chondrogenic lineage without the need to supplement the chondrogenic differentiation medium. Š 2009 Mary Ann Liebert, Inc.published_or_final_versio
LED lighting development for intelligent clothing
Author name used in this publication: K. W. E. ChengAuthor name used in this publication: Y. L. KwokAuthor name used in this publication: K. W. ChanAuthor name used in this publication: N. C. CheungAuthor name used in this publication: K. W. KwokVersion of RecordPublishe
A case-control study and meta-analysis of the association of eNOS rs1799983 SNP with stroke risk
The endothelial nitric oxide synthase (eNOS) rs1799983 polymorphism is known to increase the risk towards stroke, but data is under-reported in Malaysian population. Therefore, this study sought to investigate this association in a Malaysian population and in a comprehensive meta-analysis. Genotyping of the eNOS rs1799983 polymorphism was performed for 241 Malaysians using a hydrolysis probe. Odd ratio with 95% confidence interval was calculated. Meta-analysis was conducted using the Comprehensive Meta-Analysis software ver. 2.2.064. A p-value less than 0.05 was considered statistically significant. Overall, our results showed that the presence of eNOS rs1799983-T allele increases the risk towards stroke, particularly in males, fast-food goers and Malaysian Chinese. The meta-analysis showed that the rs1799983 polymorphism is significantly associated with an increase ischemic stroke risk in the recessive and allelic models. After stratified with population, these associations remain significant in the Asian population but not in the Caucasian population. In summary, this study establishes a significant relationship between the eNOS rs1799983 polymorphism with gender, lifestyle and ethnicity differences towards stroke risk in the Malaysian population. In addition, our meta-analysis suggests that the eNOS rs1799983 polymorphism is associated with an increase risk of ischemic stroke
Spacerless metal-manganite pseudo-spin-valve structure
Author name used in this publication: W. F. ChengAuthor name used in this publication: A. RuotoloAuthor name used in this publication: Y. K. ChanAuthor name used in this publication: K. H. WongAuthor name used in this publication: C. W. Leung2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Antiferromagnetic spintronics
Antiferromagnetic materials are magnetic inside, however, the direction of
their ordered microscopic moments alternates between individual atomic sites.
The resulting zero net magnetic moment makes magnetism in antiferromagnets
invisible on the outside. It also implies that if information was stored in
antiferromagnetic moments it would be insensitive to disturbing external
magnetic fields, and the antiferromagnetic element would not affect
magnetically its neighbors no matter how densely the elements were arranged in
a device. The intrinsic high frequencies of antiferromagnetic dynamics
represent another property that makes antiferromagnets distinct from
ferromagnets. The outstanding question is how to efficiently manipulate and
detect the magnetic state of an antiferromagnet. In this article we give an
overview of recent works addressing this question. We also review studies
looking at merits of antiferromagnetic spintronics from a more general
perspective of spin-ransport, magnetization dynamics, and materials research,
and give a brief outlook of future research and applications of
antiferromagnetic spintronics.Comment: 13 pages, 7 figure
Confined conversion of CuS nanowires to CuO nanotubes by annealing-induced diffusion in nanochannels
Copper oxide (CuO) nanotubes were successfully converted from CuS nanowires embedded in anodic aluminum oxide (AAO) template by annealing-induced diffusion in a confined tube-type space. The spreading of CuO and formation of CuO layer on the nanochannel surface of AAO, and the confinement offered by AAO nanochannels play a key role in the formation of CuO nanotubes
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Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments.
Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the θ_{Îźe} mixing angle are derived that constitute the most constraining limits to date over five orders of magnitude in the mass-squared splitting Îm_{41}^{2}, excluding the 90% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90% CL_{s} for Îm_{41}^{2}<13ââeV^{2}. Furthermore, the LSND and MiniBooNE 99% C.L. allowed regions are excluded at 99% CL_{s} for Îm_{41}^{2}<1.6âeV^{2}
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