无足辊结晶器的应用与研究

通过分析连铸作业中漏钢事故的产生原因，本公司炼钢部开发研制了以导板装置取代结晶器足辊装置的无足辊结晶器，从而提高了连铸开浇成功率，保证了连铸生产的顺利进行。     

Interfacial phenomena in the liquid copper-calcium ferrite slag system

The surface and interfacial tensions of the copper-calcium ferrite slag system were determined at 1573 K as a function of oxygen and sulfur pressures and CaO content in the slag. The effect of a 2.9 mass pct SiO₂ addition to the calcium ferrite slag was also investigated. The measurements were carried out using the sessile drop technique with a high-temperature X-ray setup. The surface tension of copper was found to be a strong function of oxygen and sulfur partial pressures. The surface tension of the calcium ferrite slag decreased slightly with CaO addition. On the other hand, CaO had a negligible effect on the interfacial tension of the system. Surface tension of the slag and the interfacial tension were influenced by the oxygen partial pressure in the system. Sulfur partial pressure also altered the interfacial tension between the copper and the ferrite slag. Based on the experimental data, filming and flotation coefficients were calculated to predict the entrainment behavior of copper, by bubble attachment in the ferrite slag.     

The epidermal growth factor receptor is not required for tumor necrosis factor-alpha action in normal mammary epithelial cells

Our laboratory has shown that tumor necrosis factor-alpha (TNF alpha) can regulate normal mammary epithelial cell (MEC) growth, morphogenesis, and, under certain circumstances, functional differentiation in a manner similar to epidermal growth factor (EGF). As TNF alpha has been shown to up-regulate EGF receptor (EGFR) expression and function in other systems, the present studies were undertaken to determine whether TNF alpha action in MEC was indirect through stimulation of the EGFR. An inhibitor of EGFR tyrosine kinase activity, PD158780, failed to block proliferation induced by 40 ng/ml TNF alpha and only partially inhibited growth in response to 2 ng/ml TNF alpha. PD158780 was also unable to suppress the extensive morphological development induced by either TNF alpha concentration. In contrast, the effects of TNF alpha and PD158780 on functional differentiation (i.e. casein accumulation) were time dependent. When measured on day 7 after 48 h of treatment, casein accumulation was unaffected by either concentration of TNF alpha or by PD158780. When assessed on day 21 after 16 days of treatment, however, casein levels were decreased by 40 ng/ml TNF alpha and increased by PD158780. Significantly, this PD158780-induced increase in casein was not observed in MEC that had been treated with both PD158780 and TNF alpha. These results thus suggest that EGFR tyrosine kinase activity is not necessary for TNF alpha action in normal MEC.     

Contingent Use of Negotiators’ Tactics in Construction Dispute Negotiation

In the course of negotiation, negotiators’ tactics should be responsive to the situational factors. This is commonly described as the contingent use of negotiators’ tactics. This study examines this concept in construction dispute negotiation and has three stages of work. Stage 1 develops taxonomies of the three construction dispute negotiation dimensions: dispute sources, negotiators’ tactics, and negotiation outcomes by exploratory factor analysis. A structural equation modeling is also used to confirm the taxonomies. Stage 2 examines the contingent use of negotiators’ tactics on outcomes respective to the dispute sources through the use of moderated multiple regression (MMR). Stage 3 discusses the findings. The dispute source, “Delay” is found to be a universal moderator in the MMR analysis of the tactic-outcome relationships. That means when the dispute source is delay, a wide range of negotiators’ tactics can be used, respective to outcome intended. It is also found that the most versatile tactics are those that seek progress. This group of tactics is effective in almost every group of dispute source and, in general, positive results can be expected. However, aggressive and assertive tactics should be used restrictively, as they will only be useful against a compromising negotiation counterpart.     

The equivalency of surface tension,surface energy and surface free energy

In much of the available literature, there is confusion regarding the correct use of the terms surface tension, surface energy and surface free energy. As a result, these three terms have been used interchangeably to describe the same quantity. This problem is particularly serious in the area of solid surface science. Linford has examined and discussed such inconsistencies but failed to differentiate the three quantities clearly. In the present paper, the definitions and the relationships between surface tension, surface energy and surface free energy are examined and their proper usage clarified.     

Design and implementation of contractual based real-time scheduler for multimedia streaming proxy server

In nowadays World Wide Web topology, it is not difficult to find the presence of proxy servers. They reduce network traffic through the cut down of repetitive information. However, traditional proxy server does not support multimedia streaming. One of the reasons is that general scheduling strategy adopted by most of the traditional proxy servers does not provide real-time support to multimedia services. Based on the concept of contractual scheduling, we have developed a proxy server that supports real-time multimedia applications. Moreover, we developed the group scheduling mechanism to enable processing power transfer between tasks that can hardly be achieved by traditional schedulers. They result in a substantially improved performance particularly when both time-constrained and non-time-constrained processes coexist within the proxy server. In this paper, the design and implementation of this proxy server and the proposed scheduler are detailed. Wai-Kong Cheuk received the B.Eng. (Hons.) and M. Phil. degrees in 1996 and 2001, respectively, from the Hong Kong Polytechnic University, where he is currently pursuing the Ph.D. degree. His main research interests include distributed operating systems and video streaming. Tai-Chiu Hsung (M'93) received the B.Eng. (Hons.) and Ph.D. degrees in electronic and information engineering in 1993 and 1998, respectively, from the Hong Kong Polytechnic University, Hong Kong. In 1999, he joined the Hong Kong Polytechnic University as a Research Fellow. His research interests include wavelet theory and applications, tomography, and fast algorithms. Dr. Hsung is also a member of IEE. Daniel Pak-Kong Lun (M'91) received his B.Sc. (Hons.) degree from the University of Essex, Essex, U.K., and the Ph.D. degree from the Hong Kong Polytechnic University, Hung Hom, Hong Kong, in 1988 and 1991, respectively. He is currently an Associate Professor and the Associate Head of the Department of Electronic and Information Engineering, the Hong Kong Polytechnic University. His research interests include digital signal processing, wavelets, multimedia technology, and Internet technology. Dr. Lun was the Secretary, Treasurer, Vice-Chairman, and Chairman of the IEEE Hong Kong Chapter of Signal Processing in 1994, 1995–1996, 1997–1998, 1999–2000, respectively. He was the Finance Chair of 2003 IEEE International Conference on Acoustics, Speech and Signal Processing, held in Hong Kong, in April 2003. He is a Chartered Engineer and a Corporate member of the IEE.