A theoretical and experimental analysis of the no-load air gap magnetic field in squirrel cage induction machines

In induction machines the tooth frequency losses due to permeance variation constitute a signif'icant, portion of the total loss. In order to predict and estimate these losses it, is essential to obtain a clear understanding of the no-load distribution of the air gap magnetic field and the magnitude of flux pulsation in both stator and rotor teeth. The existing theories and methods by which the air gap permeance variation in a doubly slotted structure is calculated are either empirical or restricted. The main objective of this thesis is to obtain a detailed analysis of the no-load air gap magnetic field distribution and the effect of air gap geometry on the magnitude and waveform of the tooth flux pulsation. In this thesis a detaiiled theoretical and experimental analysis of flux distribution not only leads to a better understanding of the distribution of no-load losses but also provides theoretical analysis for calculating the losses with greater accuracy

Seeing and believing: three episodes in the history of neurophysiology

In this contribution I look at three episodes in the history of neurophysiology that bring out the complex relationship between seeing and believing. I start with Vesalius in the mid-sixteenth century who writes that he can in no way see any cavity in nerves, even in the optic nerves. He thus questions the age-old theory (dating back to the Alexandrians in the third century BC) but, because of the overarching psychophysiology of his time, does not press his case. This conflict between observation and theory persisted for a quarter of a millennium until finally resolved at the beginning of the nineteenth century by the discoveries of Galvani and Volta. The second case is provided by the early history of retinal synaptology. Schultze in 1866 had represented rod spherules and bipolar dendrites in the outer plexiform layer as being separated by a (synaptic) gap, yet in his written account, because of his theoretical commitments, held them to be continuous. Cajal later, 1892, criticized Schultze for this pusillanimity, but his own figure in La Cellule is by no means clear. It was only with the advent of the electron microscopy in the mid-twentieth century that the true complexity of the junction was revealed and it was shown that both investigators were partially right. My final example comes from the Hodgkin-Huxley biophysics of the 1950s. Their theory of the action potential depended on the existence of unseen ion pores with quite complex biophysical characteristics. These were not seen until the Nobel-Prize-winning X-ray diffraction analyses of the early twenty-first century. Seeing, even at several removes, then confirmed Hodgkin and Huxley’s belief. The relation between seeing and believing is by no means straightforward.

The effects of persistent articholinesterase action at the neuromuscular junction

The effects of organophosphorus compounds which form a rapidly-ageing complex with acetylcholinesterase (AChE) (e.g. pinacolyl S-(2- trimethylaminoethyl)methylphosphonothioate (BOS)) and hence exert a persistent anticholinesterase (anti-ChE) action have been compared with other compounds with a shorter time course of inhibition (e.g. ecothiopate iodide (ECO)). Although the inhibition of AChE produced by BOS lasted longer than that seen with ECO, the time course of the myopathy appeared very similar. BOS also possessed a number of properties which have been seen with other anti-ChEs. BOS and ECO produced significant increases in neuromuscular "jitter" 5 days after injection, not only in the diaphragm but also in the soleus and extensor digitorum longus muscles. Increases in "jitter" produced by ECO could be prevented by pyridostigmine prophylaxis or rapid treatment with pyridine-2- aldoxime methiodide. Some protection from the BOS-induced increases in "jitter" could be gained by repeated treatment with pyridine-2-aldoxime methiodide, an effect which could not be accounted for simply by enzyme reactivation. From experiments performed in Rej 129 mice it was determined that increases in "jitter", although demonstrated in some dystrophic muscles, could not be used as an early diagnostic tool. Because sequalae of inhibition were present some time after intoxication, by which time AChE appeared biochemically normal, experiments were performed to investigate inactivation of physiologically important AChE. The time course of extracellular MEPPs was utilised as an indicator of physiologically important AChE and compared with the AChE activity measured by the technique of Ellman et al. (1961). It was concluded that the degree of persistence of anti-ChE action was unimportant for the induction of myopathy with a time course of 3-24 hours, but had some importance in events of longer duration.

The neurotoxic effects of enzyme inhibitors at the neuromuscular junction

Current knowledge of the long-term, low dose effects of carbamate (CB) anti-cholinesterases on skeletal muscle or on the metabolism and regulation of the molecular forms of acetylcholinesterase (AChE) is limited. This is largely due to the reversible nature of these inhibitors and the subtle effects they induce which has generally made their study difficult and preliminary investigations were conducted to determine suitable study methods. A sequential extraction technique was used to rapidly analyse AChE molecular form activity at the mouse neuromuscular junction and also in peripheral parts of muscle fibres. AChE in the synaptic cleft involved in the termination of cholinergic transmission was successfully assessed by the assay method and by an alternative method using a correlation equation which represented the relationship between synaptic AChE and the prolongation of extra-cellular miniature endplate potentials. It was found that inhibition after in vivo Carbamate (CB) dosing could not be maintained during tissue analysis because CB-inhibited enzyme complexes decarbamoylated vary rapidly and could not be prevented even when maintained on ice. The methods employed did not therefore give a measure of inhibition but presented a profile of metabolic responses to continual, low dose CB treatment. Repetitive and continual infusion with low doses of the CBs: pyridostigmine and physostigmine induced a variety of effects on mouse skeletal muscle. Both compounds induced a mild myopathy in the mouse diaphragm during continual infusion which was characterised by endplate deformation without necrosis; such deformation persisted on termination of treatment but had recovered slightly 14 days later. Endplate and non-endplate AChE molecular forms displayed selective responses to CB treatment. During treatment endplate AChE was reduced whereas non-endplate AChE was largely unaffected, and after treatment, endplate AChE recovered, whereas non-endplate AChE was up-regulated. The mechanisms by which these responses become manifest are unclear but may be due to CB-induced effects on nerve-mediated muscle activity, neurotrophic factors or morphological and physiological changes which arise at the neuromuscular junction. It was concluded that, as well as inhibiting AChE, CBs also influence the metabolism and regulation of the enzyme and induce persistent endplate deformation; possible detrimental effects of long-term, low-dose determination requires further investigation.

Current capacity limits and activities within the EU project MODE-GAP to overcome them

In this presentation we will discuss the implications of the so called Nonlinear Shannon Limit. We will compare technologies including new fibres for long haul transmission and techniques to expand the capacity of existing standard single mode fibres.

Bridging the gap? Corruption, knowledge and foreign ownership

We argue that in addition to host corruption per se, as accounted for by the existing literature, an explanation of inter-country variation in FDI needs to account for the distance between the host and home corruption, which we call relative corruption. We use a large matched home-host firm-level panel data-set for 1998-2006 from CEE transition countries. Year-specific selectivity corrected estimates suggest that, ceteris paribus, higher relative ‘grand’ corruption lowers foreign ownership as the returns to investment tends to be lower in more corrupt environment. However, after controlling for the selectivity bias, knowledge-intensive parent firms are found to hold controlling ownership, as the difficulty of successful joint venture looms large in more corrupt environment. Results are robust to alternative specifications.

Does move to market have an impact on earnings gap across gender? Some evidence from India

We use Indian National Sample Survey employment–unemployment data for the urban sector for the years 1987 and 1999. Our results indicate that the gender wage gap had narrowed considerably between these two years, for all earnings deciles and for all education cohorts. The narrowing of the earnings gap can be attributed largely to a sharp increase in the returns to the labour market experience of women.

The state of the art in organizational cognitive neuroscience:the therapeutic gap and possible implications for clinical practice

In the last decade, researchers in the social sciences have increasingly adopted neuroscientific techniques, with the consequent rise of research inspired by neuroscience in disciplines such as economics, marketing, decision sciences, and leadership. In 2007, we introduced the term organizational cognitive neuroscience (OCN), in an attempt to clearly demarcate research carried out in these many areas, and provide an overarching paradigm for research utilizing cognitive neuroscientific methods, theories, and concepts, within the organizational and business research fields. Here we will revisit and further refine the OCN paradigm, and define an approach where we feel the marriage of organizational theory and neuroscience will return even greater dividends in the future and that is within the field of clinical practice.

Practitioners are from Mars; academics are from Venus? An investigation of the research-practice gap in management accounting

Purpose: The aim of this paper is to identify and gain insights into the significance of barriers contributing to the purported "gap" between academic management accounting research and practice. Design/methodology/approach: Drawing on diffusion of innovations theory, this study collects and analyses data from a questionnaire survey and follow-up interviews with 19 representatives of the four principal professional accounting bodies in Australia. Findings: Professional accounting bodies perceive the gap between academic research and practice in management accounting to be of limited concern to practitioners. The two most significant barriers to research utilisation by practitioners are identified as: difficulties in understanding academic research papers; and limited access to research findings. In acting as a conduit between the worlds of academia and practice, professional bodies have an important role to play by demonstrating the mutual value to both academics and practitioners resulting from a closer engagement between MA research and practice. Research limitations/implications: As one of the few empirically-based, theoretically informed investigations exploring the research-practice gap in management accounting, this study provides insights rather than "answers". Its findings therefore serve as a foundational basis for further empirical and theoretical enquiry. Originality/value: This study contributes to the conversation about the "research-practice gap" in management accounting by adopting a distinct theoretical vantage point to organize, analyse and interpret empirical evidence obtained from Australian professional accounting bodies about management accounting practice. © Emerald Group Publishing Limited.

User involvement in UK cancer services:bridging the policy gap

Recent UK government initiatives aim to increase user involvement in the National Health Service (NHS) in two ways: by encouraging service users to take an active role in making decisions about their own care; and by establishing opportunities for wider public participation in service development. The purpose of this study was to examine how UK cancer service users understand and relate to the concept of user involvement. The data were collected through in-depth interviews, which were analysed for content according to the principles of grounded theory. The results highlight the role of information and communication in effective user involvement. Perhaps more importantly, this study suggests that the concept of user involvement is unclear to many cancer service users. This paper argues the need for increased awareness and understanding of what user involvement is and how it can work.

Bridging the gap between stylistic and cognitive approaches to authorship analysis using systemic functional linguistics and multidimensional analysis

In the present state of the art of authorship attribution there seems to be an opposition between two approaches: cognitive and stylistic methodologies. It is proposed in this article that these two approaches are complementary and that the apparent gap between them can be bridged using Systemic Functional Linguistics (SFL) and in particular some of its theoretical constructions, such as codal variation. This article deals with the theoretical explanation of why such a theory would solve the debate between the two approaches and shows how these two views of authorship attribution are indeed complementary. Although the article is fundamentally theoretical, two example experimental trials are reported to show how this theory can be developed into a workable methodology of doing authorship attribution. In Trial 1, a SFL analysis was carried out on a small dataset consisting of three 300-word texts collected from three different authors whose socio-demographic background matched across a number of parameters. This trial led to some conclusions about developing a methodology based on SFL and suggested the development of another trial, which might hint at a more accurate and useful methodology. In Trial 2, Biber's (1988) multidimensional framework is employed, and a final methodology of authorship analysis based on this kind of analysis is proposed for future research. © 2013, EQUINOX PUBLISHING.

Microwave properties of an inhomogeneous optically illuminated plasma in a microstrip gap

The optical illumination of a microstrip gap on a thick semiconductor substrate creates an inhomogeneous electron-hole plasma in the gap region. This allows the study of the propagation mechanism through the plasma region. This paper uses a multilayer plasma model to explain the origin of high losses in such structures. Measured results are shown up to 50 GHz and show good agreement with the simulated multilayer model. The model also allows the estimation of certain key parameters of the plasma, such as carrier density and diffusion length, which are difficult to measure by direct means. The detailed model validation performed here will enable the design of more complex microwave structures based on this architecture. While this paper focuses on monocrystalline silicon as the substrate, the model is easily adaptable to other semiconductor materials such as GaAs.