A micro gas turbines for UK domestic combined heat and power

Various micro-radial compressor configurations were investigated using one-dimensional meanline and computational fluid dynamics (CFD) techniques for use in a micro gas turbine (MGT) domestic combined heat and power (DCHP) application. Blade backsweep, shaft speed, and blade height were varied at a constant pressure ratio. Shaft speeds were limited to 220 000 r/min, to enable the use of a turbocharger bearing platform. Off-design compressor performance was established and used to determine the MGT performance envelope; this in turn was used to assess potential cost and environmental savings in a heat-led DCHP operating scenario within the target market of a detached family home. A low target-stage pressure ratio provided an opportunity to reduce diffusion within the impeller. Critically for DCHP, this produced very regular flow, which improved impeller performance for a wider operating envelope. The best performing impeller was a low-speed, 170 000 r/min, low-backsweep, 15° configuration producing 71.76 per cent stage efficiency at a pressure ratio of 2.20. This produced an MGT design point system efficiency of 14.85 per cent at 993 W, matching prime movers in the latest commercial DCHP units. Cost and CO2 savings were 10.7 per cent and 6.3 per cent, respectively, for annual power demands of 17.4 MWht and 6.1 MWhe compared to a standard condensing boiler (with grid) installation. The maximum cost saving (on design point) was 14.2 per cent for annual power demands of 22.62 MWht and 6.1 MWhe corresponding to an 8.1 per cent CO2 saving. When sizing, maximum savings were found with larger heat demands. When sized, maximum savings could be made by encouraging more electricity export either by reducing household electricity consumption or by increasing machine efficiency.

The effect of relative distance enlargement on visual acuity in the visually impaired

Background: Prescribing magnification is typically based on distance or near visual acuity. this presumes a constant minimum angle of visual resolution with working distance and therefore enlargement of an object moved to a shorter working distance (relative distance enlargement). this study examines this premise in a visually impaired population. methods: distance letter visual acuity was measured prospectively for 380 low vision patients (distance visual acuity between 0.3 and 2.1 logmar) over the age of 57 years, along with near word visual acuity at an appropriate distance for near lens additions from +4 d to +20 D. demographic information, the disease causing low vision, contrast sensitivity, visual field and psychological status were also recorded. results: distance letter acuity was significantly related to (r = 0.84) but on average 0.1 ± 0.2 logmar better (1 ± 2 lines on a logmar chart) than near word acuity at 25 cm with a +4 d lens addition. in 39. 8 per cent of patients, near word acuity was more than 0.1 logmar worse than distance letter acuity. in 11.0 per cent of subjects, near visual acuity was more than 0.1 logmar better than distance letter acuity. the group with near word acuity worse than distance letter acuity also had lower contrast sensitivity. the group with near word acuity better than distance letter acuity was less likely to have age-Related macular degeneration. smaller print size could be read by reducing working distance (achieved by using higher near lens additions) in 86. 1 per cent, although not by as much as predicted by geometric progression in 14. 5 per cent. discussion: although distance letter and near word acuity are highly related, they are on average 1 logmar line different and this varies significantly between individuals. near word acuity did not increase linearly with relative distance enlargement in approximately one in seven visually impaired, suggesting that the measurement of visual resolution over a range of working distances will assist appropriate prescribing of magnification aids.

An update on the characteristics of patients attending the Kooyong Low Vision Clinic

BACKGROUND: Since 1972, the Australian College of Optometry has worked in partnership with Vision Australia to provide multidisciplinary low-vision care at the Kooyong Low Vision Clinic. In 1999, Wolffsohn and Cochrane reported on the demographic characteristics of patients attending Kooyong. Sixteen years on, the aim of this study is to review the demographics of the Kooyong patient cohort and prescribing patterns. METHODS: Records of all new patients (n = 155) attending the Kooyong Low Vision Clinic for optometry services between April and September 2012 were retrospectively reviewed. RESULTS: Median age was 84.3 years (range 7.7 to 98.1 years) with 59 per cent female. The majority of patients presented with late-onset degenerative pathology, 49 per cent with a primary diagnosis of age-related macular degeneration. Many (47.1 per cent) lived with their families. Mean distance visual acuity was 0.57 ± 0.47 logMAR or approximately 6/24. The median spectacle-corrected near visual acuity was N8 (range N3 to worse than N80). Fifty patients (32.3 per cent) were prescribed new spectacles, 51 (32.9 per cent) low vision aids and five (8.3 per cent) were prescribed electronic magnification devices. Almost two-thirds (63.9 per cent) were referred for occupational therapy management and 12.3 per cent for orientation and mobility services. CONCLUSIONS: The profile of patients presenting for low-vision services at Kooyong is broadly similar to that identified in 1999. Outcomes appear to be similar, aside from an expected increase in electronic devices and technological solutions; however, the nature of services is changing, as treatments for ocular diseases advance and assistive technology develops and becomes more accessible. Alongside the aging population and age-related ocular disease being the predominant cause of low vision in Australia, the health-funding landscape is becoming more restrictive. The challenge for the future will be to provide timely, high-quality care in an economically efficient model.

Developing a categorisation system for rapists' speech

Case linkage, the linking of crimes into series, is used in policing in the UK and other countries. Previous researchers have proposed using rapists' speech in this practice; however, researching this application requires the development of a reliable coding system for rapists' speech. A system was developed based on linguistic theories of pragmatics which allowed for the categorization of an utterance into a speech act type (e.g. directive). Following this classification, the qualitative properties of the utterances (e.g. the degree of threat it carried) could be captured through the use of rating scales. This system was tested against a previously developed system using 188 rapists' utterances taken from victims' descriptions of rape. The pragmatics-based system demonstrated higher inter-rater reliability whilst enabling the classification of a greater number of rapists' utterances. Inter-rater reliability for the subscales was also tested using a sub-sample of 50 rapists' utterances and inter-item correlations were calculated. Seventy-six per cent of the subscales had satisfactory to high inter-rater reliability. Based on these findings and the inter-item correlations, the classification system was revised. The potential use of this system for the practices of case linkage and offender profiling is discussed.

Creutzfeldt-Jakob disease and vision

This review describes a group of diseases known as the transmissible spongiform encephalopathies (TSEs), which affect animals and humans. Examination of affected brain tissue suggests that these diseases are caused by the acquisition and deposition of prion protein (PrP). Creutzfeldt-Jakob disease (CJD) is the most important form of TSE in humans with at least four different varieties of the disease. Variant CJD (vCJD), a new form of the disease found in the UK, has several features that differ from the classical forms including early age of onset, longer duration of disease, psychiatric presentation (for example, depression) and extensive florid plaque development in the brain. About 10 per cent of patients with CJD exhibit visual symptoms at disease presentation and approximately 50 per cent during the course of the disease. The most commonly reported visual symptoms include diplopia, supranuclear palsies, complex visual disturbances, homonymous visual field defects, hallucinations and cortical blindness. Saccadic and smooth pursuit movements appear to be more rarely affected. The agent causing vCJD accumulates in lymphoid tissue such as the spleen and tonsils. The cornea has lymphoid tissue in the form of corneal dendritic cells that are important in the regulation of the immune response in the anterior segment of the eye. The presence of these cells in the cornea has raised the possibility of transmission between patients via optical devices that contact the eye. Although such transmission is theoretically possible it remains highly improbable.

Integration and devolvement of human resource practices in Nepal

Purpose: The purpose of this study is to explore the nature of human resource management in publicly listed finance sector companies in Nepal. In particular, it explores the extent to which HR practice is integrated into organisational strategy and devolved to line management. Design/methodology/ approach: A structured interview was conducted with the senior executive responsible for human resource management in 26 commercial banks and insurance companies in Nepal. Findings: The degree of integration of HR practice appears to be increasing within this sector, but this is dependent on the maturity of the organisations. The devolvement of responsibility to line managers is at best partial, and in the case of the insurance companies, it is more out of necessity due to the absence of a strong central HR function. Research limitations/implications: The survey is inevitably based on a small sample; however this represents 90 per cent of the relevant population. The data suggest that Western HR is making inroads into more developed aspects of Nepalese business. Compared with Nepalese business as a whole, the financial sector appears relatively Westernised, although Nepal still lags India in its uptake of HR practices. Practical implications: It appears unlikely from a cultural perspective that the devolvement of responsibility will be achieved as a result of HR strategy. National cultural, political and social factors continue to be highly influential in shaping the Nepalese business environment. Originality/value: Few papers have explored HR practice in Nepal. This paper contributes to the overall assessment of HR uptake globally and highlights emic features impacting on that uptake. © Emerald Group Publishing Limited.

The impact on domestic productivity of inward investment in the UK

One of the basic tenets of UK industrial policy, that attracting inward investment into the UK stimulates domestic productivity growth, is examined. A model of productivity growth is developed for the indigenous sector of UK manufacturing, linking domestic productivity growth to theoretical explanations of inward investment. The paper demonstrates that inward investment does stimulate productivity growth in the domestic sector of around 0.75 per cent per annum. However, this cannot be attributed to investment or output spillovers, but is a result of the productivity advantage exhibited by the foreign firms.

A comparative assessment of performance and productivity of health centres in Seychelles

Purpose - The purpose of this paper is to measure the technical and scale efficiency of health centres; to evaluate changes in productivity; and to highlight possible policy implications of the results for policy makers. Design/methodology/approach - Data envelopment analysis (DEA) is employed to assess the technical and scale efficiency, and productivity change over a four-year period among 17 public health centres. Findings - During the period of study, the results suggest that the public health centres in Seychelles have exhibited mean overall or technical efficiency of above 93 per cent. It was also found that the overall productivity increased by 2.4 per cent over 2001-2004. Research limitations/implications - Further research can be undertaken to gather data on the prices of the various inputs to facilitate an estimation of the allocative efficiency of clinics. If such an exercise were to be undertaken, researchers may also consider collecting data on quantities and prices of paramedical, administrative and support staff to ensure that the analysis is more comprehensive than the study reported in this paper. Institutionalization of efficiency monitoring would help to enhance further the already good health sector stewardship and governance. Originality/value - This paper provides new empirical evidence on a four-year trend in the efficiency and productivity of health centres in Seychelles. © Emerald Group Publishing Limited.

Organizing innovation: complementarities between cross-functional teams

Cross-functional teams play a potentially important part in the innovation process enabling knowledge sharing, the development of trust and overcoming spatial and organizational barriers. Using a supermodularity approach, we focus on potential complementarities which may arise when cross-functional teams are used in different elements of the innovation process in UK and German manufacturing plants. Using optimal combinations of cross-functional teams in the innovation process increases innovation success in the UK by 29.5 per cent compared to 9.5 per cent in Germany. Patterns of complementarity are complex, however, but are more uniform in the UK than in Germany. The most uniform complementarities are between product design and development and production engineering, with little synergy evident between the more technical phases of the innovation process and the development of marketing strategy. In strategic terms, our results suggest the value of using cross-functional teams for the more technical elements of the innovation process but that the development of marketing strategy should remain the domain of specialists.

Sex and diabetes:a thematic analysis of gay and bisexual men's accounts

Around 50 per cent of men with diabetes experience erectile dysfunction. Much of the literature focuses on quality of life measures with heterosexual men in monogamous relationships. This study explores gay and bisexual men's experiences of sex and diabetes. Thirteen interviews were analysed and three themes identified: erectile problems; other 'physical' problems; and disclosing diabetes to sexual partners. Findings highlight a range of sexual problems experienced by non-heterosexual men and the significance of the cultural and relational context in which they are situated. The personalized care promised by the UK government should acknowledge the diversity of sexual practices which might be affected by diabetes.

Exporting and innovation performance: analysis of the Annual Small Business Survey in the UK

This paper analyses the determinants of the export propensity of UK small and medium-sized enterprises (SMEs) based on the 2004 Annual Small Business Survey. Particular emphasis is placed upon the relationship between innovation activities (distinguishing product from process innovation) and export performance. In general the data suggest that some 17 per cent of firms within this group sell outside the UK. Businesses that export are also characterized by high levels of innovation activity (43 per cent of exporters innovate in products, 27 per cent innovate in process and 21 per cent innovate in both). When considering product and process innovation independently we find that both impact positively on the decision to export. However, once we consider the interdependence between both innovation activities, we find no robust evidence that process innovation increases the probability to export beyond product innovation.

Alginates as therapeutic and drug delivery systems

Alginate is widely used as a viscosity enhancer in many different pharmaceutical formulations. The aim of this thesis is to quantitatively describe the functions of this polyelectrolyte in pharmaceutical systems. To do this the techniques used were Viscometry, Light Scattering, Continuous and Oscillatory Shear Rheometry, Numerical Analysis and Diffusion. Molecular characterization of the Alginate was carried out using Viscometry and Light Scattering to determine the molecular weight, the radius of gyration, the second virial coefficient and the Kuhn statistical segment length. The results showed good agreement with similar parameters obtained in previous studies. By blending Alginate with other polyelectrolytes, Xanthan Gum and 'Carbopol', in various proportions and with various methods of low and high shear preparation, a very wide range of dynamic rheological properties was found. Using oscillatory testing, the parameters often varied over several decades of magnitude. It was shown that the determination of the viscous and elastic components is particularly useful in describing the rheological 'profiles' of suspending agent blends and provides a step towards the non-empirical formulation of pharmaceutical disperse systems. Using numerical analysis of equations describing planar diffusion, it was shown that the analysis of drug release profiles alone does not provide unambiguous information about the mechanism of rate control. These principles were applied to the diffusion of Ibuprofen in Calcium Alginate gels. For diffusion in such non-Newtonian systems, emphasis was placed on the use of the elastic as well as the viscous component of viscoelasticity. It was found that the diffusion coefficients were relatively unaffected by increases in polymer concentration up to 5 per cent, yet the elasticities measured by oscillatory shear rheometry were increased. This was interpreted in the light of several theories of diffusion in gels.

Drug targeting with phagocytic polymorphonuclear leucocytes

1. Phagocytic polymorphonuclear leucocytes (PMNLs) or neutrophils have a marked avidity for the uptake of particulate material and are the first cell type to respond to inflammatory stimuli in vivo. 2. By harnessing these pathophysiological characteristics the inherent targeting capacity of the PMNL could be exploited to carry drug loaded particles to these sites. 3. In vitro chemotaxis of PMNLs was studied in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) in the Blindwell chamber assay. 4. After phagocytosis of 1.1m polystyrene latex (PSL) beads at a range of incubation concentrations (5,10,20, and 30 beads/cell) the migration of the PMNL population was not significantly different from control, without beads. 5. The distribution of the beads within the filter showed that a disproportionately large number of PSL (50%) were associated with the cells on the surface of the filter that had not penetrated the filter. Eighty per cent of the PMNL population migrated and despite containing less PSL beads/cell, 50% of the dose was carried into the filter. Between 5 and 10% of these PSL were carried beyond 60m in the assay. 6. These results suggested heterogeneity of the PMNL population and to achieve efficient targeting with these cells preferential selection of the migratory sub-population would be needed. 7. The air-pouch model was then developed to study the focal accumulation of PMNLs in vivo. The PMNL isolated did not survive long enough in the circulation due to the trauma of the isolation procedure used; an alternative method will have to be employed.

Lead time reduction for new products

The research, which was given the terms of reference, "To cut the lead time for getting new products into volume production", was sponsored by a company which develops and manufactures telecommunications equipment. The research described was based on studies made of the development of two processors which were designed to control telephone exchanges in the public network. It was shown that for each of these products, which were large electronic systems containing both hardware and software, most of their lead time was taken up with development. About half of this time was consumed by activities associated with redesign resulting from changes found to be necessary after the original design had been built. Analysing the causes of design changes showed the most significant to be Design Faults. The reasons why these predominated were investigated by seeking the collective opinion from design staff and their management using a questionnaire. Using the results from these studies to build upon the works of other authors, a model of the development process of large hierarchical systems is derived. An important feature of this model is its representation of iterative loops due to design changes. In order to reduce the development time, two closely related philosophies are proposed: By spending more time at the early stages of development (detecting and remedying faults in the design) even greater savings can be made later on, The collective performance of the development organisation would be improved by increasing the amount and speed of feedback about that performance. A trial was performed to test these philosophies using readily available techniques for design verification. It showed that about an 11 per cent saving would be made on the development time and that the philosophies might be equally successfully applied to other products and techniques.

The mechanics of ultrasonic tube bending

The technology of precision bending of tubes has recently increased in importance and is widely demanded for many industrial applications. However, whilst attention has been concentrated on automation and increasing the production rate of the bending machines, it seems that with one exception very little work has been done in order to understand and therefore fundamentally improve the bending process. A new development for the process of draw-bending of tubes, in which the supporting mandrel is axially vibrated at an ultrasonic frequency, has been perfected. A research programme was undertaken to study the mechanics of tube• bending under both vibratory and non-vibratory conditions. For this purpose, a conventional tube-bending machine was modified and equipped with an oscillatory system. Thin-walled mild steel tubes of different diameter to thickness ratios were bent to mean bend radii having various values from 1.5 to 2.0 times the tube diameter. It was found that the application of ultrasonic vibration reduces the process forces and that the force reduction increases with increasing the vibration amplitude. A reduction in the bending torque of up to 30 per cent was recorded and a reduction in the maximum tube-wall thinning of about 15 per cent was observed. The friction vector reversal mechanism as well as a reduction in friction account for the changes of the forces and the strains. Monitoring the mandrel friction during bending showed, in some cases, that the axial vibration reverses the mandrel .mean force from tension to compression and, thus, the mandrel is assisting the tube motion instead of resisting it. A theory has been proposed to describe the mechanics of deformation during draw-bending of tubes, which embodies the conditions of both "with" and "without" mandrel axial vibration. A theoretical analysis, based on the equilibrium of forces approach, has been developed in which the basic process parameters were taken into consideration. The stresses, the strains and the bending torque were calculated utilising this new solution, and a specially written computer programme was used to perform the computations. It was shown that the theory is in good agreement with the measured values of the strains under vibratory and non-vibratory conditions. Also, the predicted bending 'torque showed a similar trend to that recorded experimentally.