Spontaneous fires in insulation

Combustible liquids may self-heat in porous insulation yielding smoldering or flaming combustion. In Part I the problem is reviewed and practical measures discussed. Using two-inch cubes of insulation and a standardized procedure, Spontaneous Ignition Temperatures (SITs) ranging from 55-184 C are reported for a series of combustible liquids. The application of a self-heating parameter Z = (AIT)/(AIT-FP), where AIT is autoignition temperature and FP is closed cup flash-point (both in Celsius), is examined. The “Z” parameter gives some indication of materials that will self-heat and those that will evaporate. For Z > 1.61 ignition occurred for all the liquids tested. Evaporation usually occurred for materials with Z < 1.35. It was found that some water-reactive or peroxide-forming materials can ignite where only evaporation would be predicted from Z value considerations. An important example of a water-reactive material is ethylene oxide (EO); the importance of EO insulation fires is that under certain conditions explosive decomposition of EO contained in the equipment can be initiated. It was previously determined that ethylene oxide reacts in porous, refractory insulations forming low molecular weight polyethylene glycols. The formation rate depends on temperature and the type and condition (particularly water content) of the insulation. Unlike EO the glycols have low volatility and may accumulate over time to several times the mass of some insulations. Under certain conditions the glycols can ignite spontaneously. In Part II experiments carried out to examine this phenomenon are discussed. Where process temperatures are above the SIT (but below the AIT), cellular glass insulation will minimize the risk of insulation fires. One disadvantage, especially for thermally unstable materials such as EO, is that cellular glass has poor fire endurance properties. The use of a realistic fire endurance test to specify insulation thickness and additional measures such as stainless steel jackets are described. Alternatives to the use of cellular glass are discussed. When selecting an insulation system, it should be determined whether an insulation fire might occur and the loss potential from such an event should be evaluated.     

THE ANALYSIS OF NET FARM INCOME: AN EXAMINATION OF FARM MANAGEMENT SURVEY DATA

The practical significance of the conventional “net farm income” is elusive. It would be useful to have an accepted method of dividing “management and investment income” into its recognised Components—managerial salary and return on tenant's capital. One is a residual if the other can be calculated, and both alternatives are considered. An empirical formula is suggested for estimating the managerial salary which may be imputed to the farmer, taking account of his total turnover, his labour bill and his net farm income. This formula is then applied to Farm Management Survey data, for individual farms and for groups of average, high and low performance (output per £ input). The method may permit closer analysis of relative profitability.     

A policy perspective on incremental innovation in small and medium sized enterprises

The increased importance of small and medium sized enterprises (SMEs) in industrial economies is explained and the very large variance in their degree of participation in the innovation process is established. Evidence from Canadian research clarifies the difficulties that smidl and medium sized firms, even in technology intensive industries, experience in developing new products and implementing new designs. Innovation theory is reviewed and the importance of inputs from specialist consultants is established for SMEs undertaking incremental innovation. Transaction costs concepts are then used to explain the difficulties SMEs encounter in arranging these linkages. A recommended form of policy to help to correct this type of market imperfection is derived and used to describe a gap in Canadian policies and to evaluate initiatives in Australia and UK.     

The political economy of tourism in the third world

When a Third World country uses tourism as a development strategy, it becomes enmeshed in a global system over which it has little control. The international tourism industry is a product of metropolitan capitalist enterprise. The superior entrepreneurial skills, resources, and commercial power of metropolitan companies enables them to dominate many Third World tourist destinations. This paper outlines the dynamics of this process, particularly in the context of the South Pacific.     

Consumer perspectives on the African sharptooth catfish in rural and urban areas of the Northern Province

This study evaluated consumer behavioural patterns in relation to meat products, with special reference to the African sharptooth catfish, in the Northern Province. Personal interviews were conducted in rural Ga‐Mamphaka and urban Giyani. The major meat type purchased was found to be chicken (71 per cent in the rural and 46 per cent in the urban community). The sharptooth catfish was found to be acceptable to the majority of respondents, both urban (69 per cent) and rural (57 per cent). Most respondents also indicated that they would like to purchase canned catfish. A potential market for catfish would seem to exist at a price competitive with that of chicken.     

National policies within the CAP

Despite the existence of the Common Agricultural Policy within the EEC a considerable number of policies still remain under national control. Professor Britton reviews these, which include several commodities, most technical activities and land tenure policy, and the ‘grey areas’ which may become subject to Community control. He points to alternative policies which might reduce some of the tensions in the CAP and urges a more positive approach by national governments. Each government should ask if it would be willing for other governments to pursue the policies which it wishes to follow for its agricultural population.     

Health and Employment amongst Older Workers*

Health and employment are strongly correlated. This paper reviews the existing evidence and brings in new evidence on the following issues: (a) the measurement of health; (b) the impact of health on employment rather than just the association between health and employment; (c) the mechanisms by which health impacts employment; and (d) the likely effect of recent retirement and disability policy changes in the UK. Although the magnitude of the estimated effect of health on employment varies greatly from study to study, some of this variation is driven by the health measure used. Given our preferred measure, the evidence suggests that 5–10 per cent of the employment decline between ages 50 and 70 is due to declining health in England, with the largest effects among low-educated men. Most of the effect comes through declining preferences for work and lower productivity when in bad health, although some of the effect is from government-provided incentives to not work when in bad health, such as from disability benefits.     

The Use of Co-ordination Theory to Improve Service Quality in Executive Search

This article considers service quality in a business service industry - execirtive search. It uses co-ordination theory to idtentify the ‘service garps’ which occur in the use of executive search consultancies and considers the ways in which these gaps can be closed. The use of an executive search consultant turns the recruitment process into a three-way relationship -between client, consultant and candidate -and raises the possibility of further service gaps than those identified in the service quality literature. This article finds that there are gaps in expectations evident in all three arms of the relationship but that they are much wider where the candidate is involved. The use of a consultant introduces uncertainty into the process (especially on the part of the candidate), the issue of who has responsibility for what within this relationship is not satisfactorily resolved or communicated. Ways in which the process can be managed to reduce the size of the expectations gaps are considered.