3,180 research outputs found

    Additive free co-deposition of nanocrystalline copper/cuprous oxide by electrodeposition

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

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    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

    An assessment of the mechanical strengths of aluminide-based thin coatings

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    Titanium aluminide and nickel aluminide-based thin coatings were synthesized by magnetron sputtering from intermetallic TiAl and Ni3Al alloy targets on nickel substrates. Both types of aluminide coating exhibited high surface hardness values that varied with the degree of heat treatment. The hardness of the coatings was investigated using micro- and nano- indentation techniques. In order to estimate the intrinsic strength of the films, the indentation size effects of the apparent hardness were analyzed by the Jönsson-Hogmark model and a model recently proposed by the authors. The analysis indicated that the strengths of the aluminide coatings may considerably exceed their strengths in bulk.published_or_final_versio

    Methods in angle-resolved photoelectron diffraction: Slab method versus separable propagator cluster approach

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    We have compared multiple-scattering results of angle-resolved photoelectron diffraction spectra between the exact slab method and the separable propagator perturbation cluster method. In the slab method, the source wave and multiple scattering within strongly scattering layers are expanded in spherical waves while the scattering among different layers is expressed in plane waves. The transformation between spherical waves and plane waves is done exactly. The plane waves are then matched across the solid-vacuum interface to a single outgoing plane wave in the detector's direction. The slab is infinitely extended parallel to the surface. Normal to the surface, enough layers are included to ensure convergence of the calculated intensity. The separable propagator perturbation approach uses two approximations; (i) A separable representation of the Green's-function propagator and (ii) a perturbation expansion of multiple-scattering terms. The cluster size is finite, typically containing 50 atoms or less. Results of this study show that using a cluster of 148 atoms, the largest cluster used to date, the cluster size is still too small for the cluster results on Ni(001) to converge with those of the slab method. Ideas to improve the perturbation expansion cluster method are discussed.published_or_final_versio

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

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    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

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

    Get PDF
    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

    Use of deltopectoral flap for head and neck reconstruction

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    Theme: Challenges to specialists in the 21st centurypublished_or_final_versio

    Nitric oxide synthase (NOS) expression and nitric oxide (NO) production in CCL4-induced hepatotoxicity of rats

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    An E2-guided E3 Screen Identifies the RNF17-UBE2U Pair as Regulator of the Radiosensitivity, Immunodeficiency, Dysmorphic Features, and Learning Difficulties (RIDDLE) Syndrome Protein RNF168

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    Protein ubiquitination has emerged as a pivotal regulatory reaction that promotes cellular responses to DNA damage. With a goal to delineate the DNA damage signal transduction cascade, we systematically analyzed the human E2 ubiquitin- and ubiquitin-like-conjugating enzymes for their ability to mobilize the DNA damage marker 53BP1 onto ionizing radiation-induced DNA double strand breaks. An RNAi-based screen identified UBE2U as a candidate regulator of chromatin responses at double strand breaks. Further mining of the UBE2U interactome uncovered its cognate E3 RNF17 as a novel factor that, via the radiosensitivity, immunodeficiency, dysmorphic features, and learning difficulties (RIDDLE) syndrome protein RNF168, enforces DNA damage responses. Our screen allowed us to uncover new players in the mammalian DNA damage response and highlights the instrumental roles of ubiquitin machineries in promoting cell responses to genotoxic stress.published_or_final_versio
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