Numerical Simulation for Droplet Combustion Using Lagrangian Hydrodynamics

A predictive model of spray combustion must incorporate models for the wide variety of physical environments in a practical combustor. In regions where droplets are closely spaced, combustion resembles a diffusion flame; where they are well separated, an envelope or wake flame results. The relative velocity field between the fuel droplets and oxidizer in influences boundary layer development about the droplet, recirculating flow patterns, and droplet shape and stability. A model must encompass these interacting temporal and spatial effects as well as complicated combustor boundaries. The objective of the current work is to develop the triangular gridding method for describing the individual and collective properties of vaporizing and burning fuel droplets

Numerical simulations of fuel droplet flows using a Lagrangian triangular mesh

The incompressible, Lagrangian, triangular grid code, SPLISH, was converted for the study of flows in and around fuel droplets. This involved developing, testing and incorporating algorithms for surface tension and viscosity. The major features of the Lagrangian method and the algorithms are described. Benchmarks of the algorithms are given. Several calculations are presented for kerosene droplets in air. Finally, extensions which make the code compressible and three dimensional are discussed

The challenges of change:Exploring the dynamics of police reform in Scotland

Despite a long tradition of pessimism regarding the scope for meaningful change in police practices, recent structural reforms to police organizations in several European countries suggest that significant change in policing is possible. Drawing on recent research into the establishment and consequences of a national police force in Scotland, this article uses instrumental, cultural and myth perspectives taken from organization theory to examine how change happened and with what effects. It highlights how police reform involves a complex interplay between the strategic aims of government, the cultural norms of police organizations and the importance of alignment with wider views about the nature of the public sector. The article concludes by identifying a set of wider lessons from the experience of organizational change in policing

Lack of association between the rs2294008 polymorphism in the prostate stem cell antigen gene and colorectal neoplasia : a case-control and immunohistochemical study

PMID: 22824379 [PubMed - indexed for MEDLINE] PMCID: PMC3500224 Free PMC ArticlePeer reviewedPublisher PD

Reservoir computing and data visualisation

We consider the problem of visualisation of high dimensional multivariate time series. A data analyst in creating a two dimensional projection of such a time series might hope to gain some intuition into the structure of the original high dimensional data set. We review a method for visualising time series data using an extension of Echo State Networks (ESNs). The method uses the multidimensional scaling criterion in order to create a visualisation of the time series after its representation in the reservoir of the ESN. We illustrate the method with two dimensional maps of a financial time series. The method is then compared with a mapping which uses a fixed latent space and a novel objective function

Combination of gastric atrophy, reflux symptoms and histological subtype indicates two distinct aetiologies of gatric cardia cancer.

<b>INTRODUCTION</b> Atrophic gastritis is a risk factor for non-cardia gastric cancer, and gastro-oesophageal reflux disease (GORD) for oesophageal adenocarcinoma. The role of atrophic gastritis and GORD in the aetiology of adenocarcinoma of the cardia remains unclear. We have investigated the association between adenocarcinoma of the different regions of the upper gastrointestinal tract and atrophic gastritis and GORD symptoms. <b>METHODS</b> 138 patients with upper GI adenocarcinoma and age and sex matched controls were studied. Serum pepsinogen I/II was used as a marker of atrophic gastritis and categorised to five quintiles. History of GORD symptoms, smoking and H.pylori infection was incorporated in logistic regression analysis. Lauren classification of gastric cancer was used to subtype gastric and oesophageal adenocarcinoma. <b>RESULTS</b> Non-cardia cancer was associated with atrophic gastritis but not with GORD symptoms; 55% of these cancers were intestinal subtype. Oesophageal adenocarcinoma was associated with GORD symptoms, but not with atrophic gastritis; 84% were intestinal subtype. Cardia cancer was positively associated with both severe gastric atrophy [OR, 95% CI: 3.92 (1.77 – 8.67)] and with frequent GORD symptoms [OR, 95% CI: 10.08 (2.29 – 44.36)] though the latter was only apparent in the nonatrophic subgroup and in the intestinal subtype. The association of cardia cancer with atrophy was stronger for the diffuse versus intestinal subtype and this was the converse of the association observed with non-cardia cancer. <b>CONCLUSION</b> These findings indicate two distinct aetiologies of cardia cancer, one arising from severe atrophic gastritis and being of intestinal or diffuse subtype similar to non-cardia cancer, and one related to GORD and intestinal in subtype, similar to oesophageal adenocarcinoma. Gastric atrophy, GORD symptoms and histological subtype may distinguish between gastric versus oesophageal origin of cardia cancer

A study of rural housing improvement in Scotland

This thesis is an attempt to establish how well the rural areas of Scotland have fared in improving their housing stock. In numerical terms the housing problems in rural Scotland do not appear to be very serious, however, as a proportion of the available stock, the problems in many areas are quite acute. Poor housing conditions in rural areas are generally associated with the most densely populated areas and tend to be concentrated in the private sector where it is more difficult for local authorities to intervene. The proportionally worst housing conditions are located in the N.W, mainland and the island areas which are characterised by crofting and are also areas which may suffer from an ''income reducing" effect. The state of the housing stock also varies within Districts and this observation highlights the need for very sensitive analysis in rural areas. The proportional size of the rural housing problem in many areas serves as an indicator of the need to improve the existing stock. However, the response of local authorities to improvement has been very varied. In recent years most rural authorities have approved some local authority rehabilitation schemes, albeit that many of these have been quite small covering only 5-10 houses on average. In view of the very small proportions of subtolerable stock in the local authority sector it is likely that some progress has been made in many rural areas. Private improvement activity on the other hand has been far more limited despite the fact that rural Scotland has had a proportionally large share of private improvement grant finance. Housing Action Areas offer local authorities a very positive approach to stimulating private improvement. However, by the end of 1978 only 10 rural Districts had declared any H.A.A.s and these were generally quite small - covering about 15 houses. Of those Districts who failed to declare any H.A.A.s, a few have approved quite nigh numbers of grants in relation to their subtolerable stock. Nevertheless, generally speaking, there has been very little progress in improving private subtolerable stock in rural Scotland. Even in the areas where quite large numbers of houses are in H.A.A.s there is still a lot more work required before any sizeable impact is made. There are a number of factors which may explain this lack of real concerted effort. Many rural authorities, rightly or wrongly, feel that H.A.A. procedures are too cumbersome and therefore unsuitable, particularly in areas where substandard stock is widely scattered. Innovation in some areas is all the more difficult because of the very small size of the Environmental Health Departments who are generally responsible for private improvement grants. It is also possible that in remoter and more rural landward areas high building costs coupled with high proportions of elderly householders may act as a barrier to improvement. Within some of the remoter areas local factors such as shortages of builders and skilled draughtsmen may also make it more difficult for some owners to improve. It is recommended that several changes be made to the existing legislative framework to overcome some of the problems associated with the present grant system. First of all it is recommended that 75% grants be made available for all properties in rural areas. Secondly that grants be made more flexible and be updated at six- monthly intervals to combat inflation. Thirdly that grants be linked to the Housing Cost Indicator to take account of Regional Cost variations. In order to try and encourage authorities to use H.A.A. procedures more widely it is suggested that these procedures be shortened for small rural schemes of houses or less. In view of the lack of innovation and activity in rural areas it is clearly necessary to both find ways of promoting the existing procedures for improving housing stock more vigorously and to devise new approaches for tackling the oustanding level of inadequate housing. It is therefore recommended that in all rural areas authorities should carry out a housing condition survey to find out the true extent of the problem in their area. Having done this it is suggested that maximum efforts be made to declare H.A.A.s in the main towns and villages and that in the landward areas careful consideration be given to the serving of improvement orders on some of the more widely scattered houses. In areas where the numbers of subtolerable houses are quite small, there may be less need to use such a positive approach in which case it may be possible to set up some form of promotional campaign to inform local people of the available grants and to apply for them. Before any active campaigns can be adopted it is essential that sufficient Government finance be made available to ensure that any enthusiasm generated is not lost becuase of lack of funds. In view of the persistent public expenditure cuts it will be very difficult to claim additional funds. However local authorities should put forward their case as strongly as possible in their housing plan reminding central Government of a) their commitment to improving existing stock, and b) the obligation they have imposed on local authorities under Section 13 of the 1974 Housing (Scotland) Act, The importance for planning of improvement work derives from the land use implications of maintenance instead of clearance or dereliction and the effects this has on the local plan process and on Regional Structure Plan Objectives