Shear enhanced heterogeneous nucleation in some Mg- and Al- alloys

Intensive shearing was applied to alloy melts at temperatures above their liquidus by using a twinscrew mechanism. The sheared melt was then cast into a TP1 mould for microstructural examination. Alloy melts with or without shearing were also filtered using the Prefil technique developed by N-Tech Ltd in order to analyse oxides and other second phase particles. The experimental results showed a significant grain refinement through enhancement of heterogeneous nucleation. The intensive melt shearing converted oxide films and agglomerates into well dispersed fine particles with a narrow size distribution. It was confirmed that the fine oxide particles can act as potent sites for nucleation during the solidification of the sheared melt. This paper presents the experimental results and theoretical analysis of shear enhanced heterogeneous nucleation during solidification of Mg- and Al-alloys. A multi-step heterogeneous nucleation mechanism has been proposed and discussed

A multiscale error diffusion technique for digital halftoning with dot-overlap compensation

Author name used in this publication: C. K. LiVersion of RecordPublishe

The enhancement of TiO?photocatalytic activity by hydrogen thermal treatment

Author name used in this publication: H. LiuAuthor name used in this publication: X. Z. Li2002-2003 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

A dual-memory permanent magnet brushless machine for automotive integrated starter-generator application

This paper presents a dual-memory permanent magnet brushless machine for automotive integrated starter-generator (ISG) application. The key is that the proposed machine adopts two kinds of PM materials, namely NdFeB and AlNiCo for hybrid excitations. Due to the non-linear characteristic of demagnetization curve, AlNiCo can be regulated to operate at different magnetization levels via a magnetizing winding. With this distinct merit, AlNiCo can provide the assistance for online tuning the air-gap flux density. Firstly, the configuration of proposed machine is presented. Secondly, the finite element method (FEM) is applied for the field calculation and performance verification. Finally, both simulation and experimental results confirm that the proposed machine is very suitable for the ISG application. © 2012 IEEE.published_or_final_versio

An error diffusion technique with reduced directional hysteresis

Author name used in this publication: K. T. LoAuthor name used in this publication: C. K. LiCentre of Digital Signal Processing for Multimedia Applications, Department of Electronic and Information EngineeringVersion of RecordPublishe

A novel osmosis membrane bioreactor-membrane distillation hybrid system for wastewater treatment and reuse

© 2016 . A novel approach was designed to simultaneously enhance nutrient removal and reduce membrane fouling for wastewater treatment using an attached growth biofilm (AGB) integrated with an osmosis membrane bioreactor (OsMBR) system for the first time. In this study, a highly charged organic compound (HEDTA3-) was employed as a novel draw solution in the AGB-OsMBR system to obtain a low reverse salt flux, maintain a healthy environment for the microorganisms. The AGB-OsMBR system achieved a stable water flux of 3.62 L/m2 h, high nutrient removal of 99% and less fouling during a 60-day operation. Furthermore, the high salinity of diluted draw solution could be effectively recovered by membrane distillation (MD) process with salt rejection of 99.7%. The diluted draw solution was re-concentrated to its initial status (56.1 mS/cm) at recovery of 9.8% after 6 h. The work demonstrated that novel multi-barrier systems could produce high quality potable water from impaired streams

Worsened arterial stiffness in high-risk cardiovascular patients with high habitual carbohydrate intake: a cross-sectional vascular function study

BACKGROUND: Previous studies suggested that high dietary carbohydrate intake is associated with increased cardiovascular risk through raised triglyceride and decreased high-density lipoprotein-cholesterol levels. However, the relation between carbohydrate intake and arterial stiffness has not been established. The purpose of this study was to examine this relation among high-risk cardiovascular patients. METHODS: We studied the relation between dietary macronutrient intake and arterial stiffness in 364 patients with documented cardiovascular diseases or risk equivalent (coronary artery diseases 62%, ischemic stroke 13%, diabetes mellitus 55%) and in 93 age-and-sex matched control subjects. Dietary macronutrient intake was assessed using a validated food-frequency questionnaire (FFQ) for Chinese. Heart-ankle pulse wave velocity (PWV) was measured non-invasively with a Vascular Profiling System (VP2000, Colin Corp. USA). A dietary pattern with >/=60% total energy intake derived from carbohydrates was defined as a high-carbohydrate diet according to the Dietary Reference Intakes (DRI) for Chinese. RESULTS: Subjects who consumed a high-carbohydrate diet had significantly higher mean PWV than those who did not consume a high-carbohydrate diet (P = 0.039). After adjustment for potential confounders, high-carbohydrate diet was associated with significantly increased PWV [B = 73.50 (10.81 to 136.19), P = 0.022]. However, there was no significant association between high-carbohydrate diet and PWV in controls (P = 0.634). CONCLUSIONS: High-carbohydrate diet is associated with increased arterial stiffness in patients with established cardiovascular disease or risk equivalent.published_or_final_versio

Melt conditioning by advanced shear technology (MCAST) for refining solidification microstructures

MCAST (melt conditioning by advanced shear technology) is a novel processing technology developed recently by BCAST at Brunel University for conditioning liquid metal prior to solidification processing. The MCAST process uses a twin screw mechanism to impose a high shear rate and a high intensity of turbulence to the liquid metal, so that the conditioned liquid metal has uniform temperature, uniform chemical composition and well-dispersed and completely wetted oxide particles with a fine size and a narrow size distribution. The microstructural refinement is achieved through an enhanced heterogeneous nucleation rate and an increased nuclei survival rate during the subsequent solidification processing. In this paper we present the MCAST process and its applications for microstructural refinement in both shape casting and continuous casting of light alloys

Deep vein thrombosis and pulmonary embolism in the Chinese population

Deep vein thrombosis and pulmonary embolism is a well-recognised major health problem in the West. There is a deep-rooted belief among clinicians that deep vein thrombosis is rare in Asians, particularly in the Chinese population. However, it appears that the incidence of venous thrombosis and pulmonary embolism is increasing in Chinese patients. Prophylaxis reduces the incidence of venous thrombosis by 66% and of pulmonary embolism by 50%Ը? prophylaxis should therefore be considered for Chinese patients who have a high risk of developing postoperative deep vein thrombosis. This report reviews the current literature on this subject.published_or_final_versio