3,777 research outputs found
The behavior of two-way reinfoced concrete slabs externally strengthened with steel plate to subject patch load
2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Investigation of polymer bonded magnetic materials for power conversion
Author name used in this publication: K. W. E. ChengAuthor name used in this publication: C. Y. TangAuthor name used in this publication: D. K. W. ChengAuthor name used in this publication: H. WuAuthor name used in this publication: Y. LuPower Electronics Research Centre, Department of Electrical EngineeringRefereed conference paper2001-2002 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Leakage field modeling of spiral winding transformer for contactless power converters
Author name used in this publication: K. W. E. ChengAuthor name used in this publication: Y. LuAuthor name used in this publication: K. W. ChanAuthor name used in this publication: Y. L. KwokAuthor name used in this publication: K. W. KwokAuthor name used in this publication: X. D. XueRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Design of three-dimensional fitted garment pieces in a virtual environment
2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Isolation and Purification of Sesquiterpene Lactones from Ixeris sonchifolia (Bunge) Hance by High-Speed Counter- Current Chromatography and Semi-Preparative High Performance Liquid Chromatography
Purpose: To isolate and purify sesquiterpene lactones from Ixeris sonchifolia (Bunge) Hance by highspeed counter-current chromatography (HSCCC).Methods: I. sonchifolia was extracted with water and then loaded on a glass column (10 ~ 1500 cm containing 3000g D101 macroporous resin) where various concentrations of aqueous ethanol (0, 10, 30, 50, and 95 %) were used to elute the column successively. The 50 % ethanol fraction was purified by HSCCC using a solvent system comprised of ethyl acetate: n-butanol: methanol: water (4: 6: 1: 20, v/v), and semi-preparative high performance liquid chromatography (HPLC). The chemical structures of thecomponents obtained were further confirmed by high-resolution mass spectroscopy (MS) and nuclear magnetic resonance spectroscopy (NMR).Results: Three compounds, including ixerin Z1 (0.7 mg), ixerin Z (11.4 mg), and 11, 13α-dihydroixerin Z (8.2 mg), with purity of 96.2, 98.2, and 98.4 %, respectively, were obtained from 200 mg each of the 50 % ethanol fraction.Conclusion: HSCCC is a rapid and effective method for isolating and purifying sesquiterpene lactones from I. sonchifolia.Keywords: Sesquiterpene lactones, High-speed counter-current chromatography, Ixeris sonchifolia, Ixerin, 13α-Dihydroixeri
Suppression of nickel release in nickeltitanium alloys by plasma immersion ion implantation surface treatment: towards a new generation of "smart" orthopaedic implants
Summary form only given. Nickel-titanium shape memory alloys (NiTi) are potentially very useful in spinal deformity correction due to their super elastic properties and their ability to change shape with temperature. However, release of toxic nickel particulate debris remains a major concern. We have developed a novel method of altering the surface of the material to reduce nickel release by using plasma immersion ion implantation (PIII). This study compares the corrosion resistance and mechanical properties of PIII treated samples with untreated NiTi. NiTi discs containing 50.8% Ni were implanted with nitrogen using PIII technique. Their elemental depth profile, surface chemical composition, surface hardness and corrosion resistance were compared with untreated NiTi. The amount of Ni released into simulated body fluids after the accelerated corrosion tests were determined. The biocompatibility was assessed by culturing mouse osteoblasts expressing an enhanced green fluorescent protein on the surface of these materials. After PIII treatment, a layer of titanium nitride formed on the surface. Compared to untreated NiTi, the corrosion resistance is better by five times, and the surface hardness and elastic modulus are better by a factor of 2. The concentration of Ni in the simulated body fluid for the untreated sample was 30 ppm compared to undetectable levels in the PIII treated sample. There was no difference in the ability of cells to grow on either surface. PIII results in enhanced corrosion and wear resistance, and negligible Ni release. This technique will allow NiTi alloys to be safely implanted in the human body. A new generation of "smart" orthopaedic implants will likely result.published_or_final_versio
PolyUCOMP in TAC 2011 entity linking and slot filling
The Text Analysis Conference (TAC) is organized by the U.S. National Institute of Standards and Technology (NIST).2011-2012 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
New plasma surface-treated memory alloys: Towards a new generation of "smart" orthopaedic materials
This paper describes the corrosion resistance, surface mechanical properties, cyto-compatibility, and in-vivo performance of plasma-treated and untreated NiTi samples. Nickel-titanium discs containing 50.8% Ni were treated by nitrogen and carbon plasma immersion ion implantation (PIII). After nitrogen plasma treatment, a layer of stable titanium nitride is formed on the NiTi surface. Titanium carbide is also found at the surface after carbon plasma implantation. Compared to the untreated samples, the corrosion resistances of the plasma PIII samples are better by a factor of five and the surface hardness and elastic modulus are better by a factor of two. The concentration of Ni leached into the simulated body fluids from the untreated samples is 30 ppm, whereas that from the plasma-treated PIII are undetectable. Although there is no significant difference in the ability of cells to grow on either surface, bone formation is found to be better on the nitrogen and carbon PIII sample surfaces at post-operation 2 weeks. All these improvements can be attributed to the formation of titanium nitride and titanium carbide on the surface. © 2007 Elsevier B.V. All rights reserved.postprin
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