Mill House Refractories

Some of the important aspects involved in designing a furnace relate generally to (I) robustness of construction (2) ease of control, (3) ease of maintenance and (4) maximum utilisation of heat energy produced in the furn- ace. With a view to ensuring improved performances, the reheating and heat treatment furnaces are now being designed as complicated and precise units In place of simple bricklined boxes, hitherto employed. The demand on the quality of refractories for application in the different zones of such furnaces have become increasingly stringent

Recognising facial expressions in video sequences

We introduce a system that processes a sequence of images of a front-facing human face and recognises a set of facial expressions. We use an efficient appearance-based face tracker to locate the face in the image sequence and estimate the deformation of its non-rigid components. The tracker works in real-time. It is robust to strong illumination changes and factors out changes in appearance caused by illumination from changes due to face deformation. We adopt a model-based approach for facial expression recognition. In our model, an image of a face is represented by a point in a deformation space. The variability of the classes of images associated to facial expressions are represented by a set of samples which model a low-dimensional manifold in the space of deformations. We introduce a probabilistic procedure based on a nearest-neighbour approach to combine the information provided by the incoming image sequence with the prior information stored in the expression manifold in order to compute a posterior probability associated to a facial expression. In the experiments conducted we show that this system is able to work in an unconstrained environment with strong changes in illumination and face location. It achieves an 89\% recognition rate in a set of 333 sequences from the Cohn-Kanade data base

On-farm maize storage systems and rodent postharvest losses in six maize growing agro-ecological zones of Kenya

Rodents are one of the major postharvest pests that affect food security by impacting on both food availability and safety. However, knowledge of the impact of rodents in on-farm maize storage systems in Kenya is limited. A survey was conducted in 2014 to assess magnitudes of postharvest losses in on-farm maize storage systems in Kenya, and the contribution of rodents to the losses. A total of 630 farmers spread across six maize growing agro-ecological zones (AEZs) were interviewed. Insects, rodents and moulds were the main storage problems reported by farmers. Storage losses were highest in the moist transitional and moist mid-altitude zones, and lowest in the dry-transitional zone. Overall, rodents represented the second most important cause of storage losses after insects, and were ranked as the main storage problem in the lowland tropical zone, while insects were the main storage problem in the other AEZs. Where maize was stored on cobs, total farmer perceived (farmer estimation) storage weight losses were 11.1 ± 0.7 %, with rodents causing up to 43 % of these losses. Contrastingly, where maize was stored as shelled grain, the losses were 15.5 ± 0.6 % with rodents accounting for up to 30 %. Regression analysis showed that rodents contributed significantly to total storage losses (p < 0.0001), and identified rodent trapping as the main storage practice that significantly (p = 0.001) lowered the losses. Together with insecticides, rodent traps were found to significantly decrease total losses. Improved awareness and application of these practices could mitigate losses in on farm-stored maize

Chrome-alumina refractories

Invéstigations were carried out with different types of bauxites and chromites to prepare chrome-alumina refractories. Raw materials mixed in suitable proportions to give 10–12 percent Cr2O3 in the product were calcined at 1600° and then graded. Bricks formed under pressure and fired to 1600° indicate promising results but high porosity. Lime addition (2–3%) in the mixes appreciably reduces porosity but slightly affects the refractoriness. Chrome ores containing about 5 percent silica is suitable for the purpose. Chrome-alumina refractories thus made possess desirable properties and their use in steel pouring ladles and regenerators of open hearth furnaces may be considered. © 1964 Taylor &amp; Francis Group, LLC

Mullite Refractories from Clay-Bauxite or Quartz-Bauxite Mixes

Investigations were undertaken to study the properties of mullite refractories from Katni and Shevroy bauxites with addition of Jabalpur fire-clay or quartz. Mullite was estimated by chemical analysis and confirmed by X-ray and petrographic examination. Refractories hewing 80–90 per cent mullite could be prepared out of these mixes after firing at temperatures 1500°-1600°C. In spite of high mullite content the porosity of these refractories was very high (35–48 per cent) and the refractoriness under load particularly initial softening point (Ta) was rather low (1400°-1600°C). These may be due to incipient growth of mullite crystals and lack of inter-crystalline bond. © 1965, Taylor and Francis Group, LL

On the significance of fabrication and characterisation of ceramic porous cup for agro industries

The mode of fabrication of porous ceramic cups of different compositions and the role of processing variables, relevant in this context, have been highlighted. The significance of the consistency of slip and the characterisation of plaster mould with respect to ensuring the quality of cast products have been dwelt upon. The nature, amount and distribution of pores and the mode of their evaluation were also discussed.An overall effort of the investigation was to indicate the important features considered significant for application of porous ceramic wares in the tensiometer with special reference to agro industry. The mechanism of pore function and soil water tension in this particular application have been elaborated. The criteria of selection of these wares for satisfactory application, and the performance of the products developed at CGCR1 were indicated. © 1979, Taylor & Francis Group, LLC