diVerent thermal expansion coeYcients) which, during the subsequent heating and cooling cycles of the ladle, results Ladle glazes are a thin coating of slag formed when in stresses and eventually to 'spalling' of the refractory. the top slag comes in contact with the refractory Thus, the aims of this research programme were to during draining of the ladle. It is believed that ladle obtain direct evidence that ladle glazes are a major source glazes are a major source of inclusions in the next of inclusions; to study the factors in uencing the adhered cast of steel held in that ladle. Pilot plant trials, slag layer, in particular, the thickness of this layer; and to simulation tests, and thermophysical property study the factors controlling the formation and the depth measurements have been carried out on the glazes of slag penetration. to: (i) obtain more information about ladle glazes and the factors affecting their formation and GLAZE FORMATION subsequent removal from the refractory; (ii) provide direct evidence that glazes are a major source of Pilot plant trials were carried out on a 4 t ladle lined with inclusions; (iii) study the factors affecting the (MgO +3% C) bricks and with a rammable MgO base. formation, adhesion, and thickness of the glaze; (iv)The ladle was allowed to cool after each cast and was then study the formation of the slag penetrated layer and reheated for each subsequent cast. A short sequence of the factors affecting penetration. Doping trials have representative steel grades was then cast in the ladle (the last shown that ladle glazes are a major source of being an aluminium killed steel). The ladle was carefully inclusions. The calculated thickness of the adhered dismantled and examined. slag layer was appreciably lower than measured experimental values. Calculated horizontal slag Characteristics of glaze infiltration depths were in reasonable agreementThe following observations were made from examinations with values measured on plant, but measured of the specimens of refractory plus glaze: vertical infiltration depths were much lower than (i) the glaze thickness was 10-15 mm in the bottom calculated values. It has been shown that slag half of the ladle, but tended to be both thicker and penetration can be significantly reduced by the more variable in the upper part of the ladle (Fig. 1a) application of an electrical potential.I&S/1682 (ii) microscopic examination of specimens taken from diVerent heights in the ladle revealed a clear interface Dr Riaz and Mr Bain are at the Corus Group Teesside Technology between the refractory and the slag impregnated Centre, Grangetown, Middlesbrough, UK and Professor Mills is in region in the decarburised region of the refractory the Department of Materials, Imperial College, London SW7 2BP, UK

Hazard analyses (which included watching operations, measuring temperatures of foods throughout preparation and display, and sampling and testing for microorganisms of concern) were conducted of vending operations at a railway and a bus station in a large city in Pakistan. Commonly prepared foods which were surveyed included: rice, pulses, chick peas, ground meat and potato mixtures, meat stew, and okra. Temperatures were measured and samples were collected from a variety of other foods. Large numbers (104–7) of Clostridium perfringens were isolated from samples of pulses, ground meat dishes, and chick peas collected during display, 8 to 10 h after cooking. Aerobic colony counts were also high in these and other foods that were held for several hours, unless hot, at temperatures >55°C throughout the holding periods or periodic reheating practiced (which was done by a few vendors). Cooking was usually thorough, but spores survived which germinated during the display period. High temperature holding or periodic reheating maintained safe foods, and hence, are critical control points for these operations. Education about these matters ought to be directed at health and transportation authorities, vendors, and the public.

N Annual publication rate N Geographical origin of the work N Nature of the research (e.g. thermodynamics, kinetics) N Nature of the slag studied.This study has revealed that slag research in the USA and Europe has decreased to about a half over the last 20 years and that there has been a significant decrease in Japanese research in this area in recent years. However, these decreases have been offset by significant increases in Chinese and Korean research activity. There has been a significant increase in the amount of work carried out on recycling and environmental aspects of slags in recent years.

Hazard analyses (which included watching operations, measuring temperatures of foods throughout preparation and display, and sampling and testing for microorganisms of concern) were conducted of vending operations of chicken, rice, pulse patties, and ice cream in a resort town in Pakistan. Salmonellae were isolated from ground meat, chicken flesh (from all operations surveyed), cutting boards, egg shells (eggs used in pulse patties), and buffalo milk (used for milk shakes). Greater than 105 coliform bacteria were isolated from raw milk, ice-cream mixes and products, and pulse-patty mix. Time-temperature exposure during cooking was adequate to kill salmonellae, but there were potentials for recontamination from cutting boards, knives, and hands of the vendor. Buffalo milk was held in a freezer and not boiled by the vendor as is usual in Pakistani homes to retard spoilage. Hence, because pathogens were not killed, milk shakes were a health risk. Pulse patties were not always thoroughly cooked, so pathogens could have survived. Holding stacks of them on a griddle for several hours would have allowed germination and growth of bacterial spores and growth of resulting cells. Health agency personnel in developing countries, vendors, and consumers of these foods need to be informed of the hazards and appropriate preventive measures.

A hazard analysis (which included watching operations, measuring temperatures of foods throughout preparation and display, and sampling and testing for microorganisms of concern) was conducted of a street vendor's operation. Chat is a popular dish in certain areas of Pakistan. It consists of sliced cooked potatoes, fried graham and pulse dough, and chick peas or red beans garnished with lasi (a fermented milk) and a fruit syrup. Staphylococci reached the cooked potatoes during peeling, cutting, and other handling. These bacteria increased up to 105 while the contaminated foods were held for several hours. Counts up to 105 Bacillus cereus were isolated from the cooked doughs after a 6-h or longer holding period. Large numbers (usually >105) of coliform bacteria and aerobic mesophilic colonies (106–9) were isolated from all foods after handling and holding for several hours. Ingestion of these foods must be considered high risk unless handling of cooked items can be kept to a minimum and the time of holding reduced to less than 6 h. Critical control points are handling after cooking and holding on display. Health agency personnel in developing countries, vendors, and consumers of these foods need to be informed of the hazards and appropriate preventive measures.

During the current research and development activities at Tata Steel Teesside Technology Centre, UK, the inclined plane test (IPT) is adopted as a quick method to measure the viscosity/ fluidity of mould powders being used currently for continuous casting of different steel qualities and section sizes. The usefulness of the IPT method was also validated by comparing the viscosities that were measured by a high temperature viscometer. It has been established that the IPT measured viscosity values are comparable with the mould powder supplier's data. The IPT ribbon lengths of different powders have been correlated with the viscosities using an Arrhenius type relationship. The ribbon lengths of the solidified fluxes were found to have a good correlation with the molar ratios of the corresponding powders. Hence, the relationship was further tuned to develop a viscosity prediction model using the chemical compositions of the mould fluxes (i.e. the model can be used for a quick assessment of mould flux viscosity based on its chemical composition).

The influence of a swirling flow inside the submerged entry nozzle on the structure and the stability of a liquid metal flow in a physical model of a slab casting mould are investigated. For visualisation of the flow, contactless inductive flow tomography (CIFT) is applied. As expected and desired, the swirling flow leads to a stronger upward fluid motion along the walls. At the same time, however, the oscillatory character of the flow becomes stronger. These flow features obtained with CIFT are shown to be in reasonable agreement with independent measurements using ultrasonic Doppler velocimetry. Preliminary results of numerical simulations also show a similar behaviour.

Starting in 1997 with the 5th International Conference on Slags and Fluxes a survey on research on slags has been done preceding the next conference on slags and fl uxes. Trends from 1980, the year of the fi rst conference in Halifax, Canada, have been traced and discussed. In the present paper the recent trends in slag-related research from 2004 to 2007 is analysed in terms of: • Annual publication rate • Geographical origin of the work • Nature of the research (e.g. thermodynamics, kinetics) • Nature of the slag studied.Earlier study has revealed that in the beginning of the new millennium a publication rate of one paper on slags per day was produced world wide.From the new survey it is found that since 2003 the number of publications has increased remarkably, leading to a doubling in 2006 equivalent to two papers on slags published per day world wide. The underlying mechanism of this increase is presented and discussed. There has been a signifi cant increase in the amount of work carried out on the recycling and environmental aspects of slag in recent years.