Wind generator behaviour in a pay-as-bid curtailment market

A pay-as-bid curtailment market, where Wind Power Plants (WPPs) may offer prices to have their output reduced in the event of network balancing or stability constraints, is one approach towards the market integration of a high proportion of wind energy onto a power system. Such a market aims to procure curtailment at a cost close to the marginal value of the electricity plus renewable subsidies and incentives, reducing risks for WPPs while minimising costs to the Independent System Operator (ISO). Through the use of game theory and market modelling, a key set of bidding strategies are identified that may evolve within such a market, which may act in opposition to the goals of the ISO. These are applied to a variety of network conditions in order to determine their likely impact and the resulting bidding signals provided to market participants. Bidding behaviours and market fluidity may also be affected by factors particular to wind power plants. Through analysis of both ex ante and ex post case studies, the existence of these behaviours is demonstrated, illustrating that a pay-as-bid curtailment market may not be efficient at price discovery in practice

A successor to ER P2/6 : existing issues and lessons from "Flexible Networks for a Low Carbon Future"

This note is concerned with a network's ability to meet demand for power. In other words, with 'security of supply' and, in particular, with standards or conventions that drive a distribution network planner’s decisions in respect of ensuring that demand will be met in future. It takes lessons from the “Flexible Networks” Low Carbon Networks Fund project in respect of ‘flexible’ network actions such as dynamic or real-time ratings, network reconfiguration and voltage regulation along with learning from network monitoring, not least to aid better forecasting of demand, and applies them in respect of possible development of a successor to the main standard that drives network investment to provide adequate reliability of supply to distribution connected demand, Engineering Recommendation (ER) P2/6, i.e. the 6th edition of ER P2. This note discusses a number of issues in respect of ER P2/6, its application by Distribution Network Operators (DNOs) and its interactions with other regulatory initiatives, not least the Interruption Incentive Scheme (IIS) and ‘load indices’

Methods and Tools for Planning the Future Power System : Issues and Priorities

This report contributes to discussion of the nature of the future power system in the context of the IET’s ‘Power Networks Joint Vision’ initiative. It summarises a number of future challenges arising from the changing nature of generation and demand and the possibility of greater demand-side participation in electricity markets. It argues that these require significant change in respect of current practice in the assessment, planning and development of power network facilities enabling future system operation. It reflects on methods and tools used by network planners in Britain today and discusses areas in which modelling capability needs to be developed and enhanced data or user competencies are required

Development of a polyclonal competitive enzyme-linked immunosorbent assay for detection of antibodies to Ehrlichia ruminantium

A polyclonal competitive enzyme-linked immunosorbent assay (PC-ELISA) is described for detection of antibodies to Ehrlichia (Cowdria) ruminantium by using a soluble extract of endothelial cell culture-derived E. ruminantium as the antigen and biotin-labeled polyclonal goat immunoglobulins as the competitor. For goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of 80% inhibition (80 PI), with detection of antibodies for 550 days postinfection. For cattle, diagnostic sensitivity and specificity were 86 and 100%, respectively, with a cutoff of 50 PI and 79 and 100% with a cutoff of 70 PI. Cross-reactions with high-titer experimental or field antisera to other Ehrlichia and Anaplasma species were observed at up to 68 PI in cattle and up to 85 PI in sheep, and therefore to exclude these cross-reactions, cutoffs of 70 PI for bovine serology and 85 PI for small-ruminant serology were selected. Application of the PC-ELISA to bovine field sera from South Africa gave a higher proportion of positive results than application of the murine macrophage immunofluorescent antibody test or indirect ELISA, suggesting a better sensitivity for detection of recovered cattle, and results with bovine field sera from Malawi were consistent with the observed endemic state of heartwater and the level of tick control practiced at the sample sites. Reproducibility was high, with average standard deviations intraplate of 1.2 PI and interplate of 0.6 PI. The test format is simple, and the test is economical to perform and has a level of sensitivity for detection of low-titer positive bovine sera that may prove to be of value in epidemiological studies on heartwater

SOAR (Support Office for Aerogeophysical Research) Annual Report 1994/1995

The Support Office for Aerogeophysical Research (SOAR) was a facility of the National Science Foundation's Office of Polar Programs whose mission is to make airborne geophysical observations available to the broad research community of geology, glaciology and other sciences. The central office of the SOAR facility is located in Austin, Texas within the University of Texas Institute for Geophysics. Other institutions with significant responsibilities are the Lamont­ Doherty Earth Observatory of Columbia University and the Geophysics Branch of the U.S . Geological Survey. This report summarizes the goals and accomplishments of the SOAR facility during 1994/1995 and plans for the next year.National Science Foundation's Office of Polar ProgramsInstitute for Geophysic

The development and validation of a murine model for studying the role of histamine receptors in acute and chronic itch

Itch (pruritus) is an unpleasant sensation of the skin, which evokes the desire to scratch. The condition commonly presents in clinical practice, as a symptom of systemic disease and various skin disorders, such as atopic dermatitis. Itch has tended to be closely associated with pain, and older evidence suggests that the sensations involve the same sensory nerves, firing at different frequencies. Partly because of this, and the subjective cognitive nature of the condition, itch has been relatively ignored as a research area and there is a general lack of effective animal models for studying itch. This has restricted detailed studies into putative mediators of itch and their mechanism(s) of action.The present studies were undertaken to develop and validate acute and chronic models of itch in mice, based on the combined use of behavioural tests in awake mice and in vivo electrophysiological recordings from itch afferents in anaesthetized animals. The hypothesis was that scratching behaviour can be evoked in mice using intradem1al injections of pruritogenic drugs and that this can be measured automatically and objectively to provide a reliable indicator of itch. A further hypothesis was that electrophysiological recordings made in vivo from murine cutaneous sensory nerves can be used to distinguish between pruritogens and algogens.The model of itch that was developed is based on injection of histamine into the back of the mouse neck to evoke scratching of the area by the hind paws. Histamine is a pruritogen in both humans and mice, although the lack of effectiveness of traditional H 1-receptor antihistamines in treating all clinical itch disorders suggests other mediators are also responsible for pruritus. The studies demonstrated that scratching in mice can be induced using histamine and other pruritogens (e.g. trypsin and 5-HT) in a reproducible dose dependent manner. Scratching was established as a response to itch-provoking agents, but not to painful stimuli. A novel mechanism of histamine evoked scratching involving H4 receptors was discovered. Chronic itching 111 response to topical application of dinitrochlorobenzene was also established. A robust automated method for the detection and measurement of scratching in mice was developed, which considerably enhances accuracy and reduces the time taken, in comparison with manual observation of scratching.In vivo electrophysiological recordings showed that pruritogens evoke a pattern of response in cutaneous nerves distinct in nature from that evoked by algogenic stimuli. However, nerves responded to both stimuli, suggesting that in mice, there are probably no independent 'pruritoceptors', unlike the situation in man. In summary, scratching in mice can be recorded automatically and used as a reproducible quantitative measure of itch. This model can be used for further studies on putative mediators of itch to establish their mechanism of action. Knowledge from such studies should provide understanding of the sensation of itch in man, and should facilitate the development of novel therapies specific for pruritus

Business to Business Enterprise Integration: An exploratory study to develop and test an implementation model for engineer to order organisations.

This research explores the managerial problems associated with adoption of business to business (B2B) enterprise integration in the UK engineer to order (ETO) manufacturing sector. Its aim is to develop a B2B enterprise integration hierarchy to overcome managerial problems and propose a model for implementation. The first part of the research developed an overview of the evolution of the B2B enterprise integration concept, a definition, perceived business benefits and its general status in the UK manufacturing sector. The research is grounded in the extant literature covering supply chain integration, information technology acceptance literature, crisis management and implementation success factors. A qualitative case study approach was selected comprising two phases. The first phase involved key informant interviews at eleven ETO companies in the UK. Three interviews with key informants were carried out at each company. This group triangulation approach mitigated any bias. Four managerial problems were identified: management awareness of the benefits and implementation challenges, risk in terms of return on investment and business continuity during implementation, information security risk associated with loss of competitive advantage and lack of relevant skills within the organisation. From these findings, a B2B de-coupled integration hierarchy was developed and an implementation model proposed. The second phase involved an in case participatory action research study over a one year budget cycle at one of the eleven companies during implementation of a B2B system. This case study tested the use of a B2B de-coupled integration hierarchy approach and refined the proposed implementation model. The outcome of the research recommends a B2B de-coupled integration hierarchy and an iterative implementation model for overcoming the four key inhibitors identified. This is significant for practitioners, particularly in the ETO sector, who are in the process of implementing B2B enterprise integration systems. It confirms that successful implementation can be achieved if senior management teams are fully aware of the potential benefits and the implementation challenges. Additionally, business and information security risks must be dealt with by appropriate de-coupling and the workforce should have the relevant skills to deal with the new systems. From an academic perspective, this research provides two significant contributions. This is the first study to explore the managerial problems associated with adoption of B2B enterprise integration by using a combination of interviewing key informants within an organisational setting and a participatory action case study. Furthermore, it is the first study to propose an iterative implementation model to overcome managerial problems associated with adoption of B2B enterprise integration in the UK ETO sector. It should be noted that this research is limited to key informant interviews at eleven companies and one case study. In order to provide unequivocal validation and generalisability, the research should be expanded to cover other manufacturing sectors

The novels of Salvador Garmendia :

This study is divided into four main parts in which the five novels of Venezuelan Salvador Garmendia are analyzed on the bases of theme, characterization, structure and style. The novels are Los pequenos seres (1959), Los habitantes (1961), D(')ia de cenzia (1963), La mala vida (1968) and Los pies de barro (1973).The novels of Salvador Garmendia are thematically homogeneous. Although they take place in different barrios of Caracas, they are similar in their portrayal of the anguish of modern city life. Garmendia recreates the traditional Venezuelan protagonist into an alienated and frustrated antihero. This character demonstrates both individual and universal qualities to the most intimate details. Garmendia's unmasking of his ironic heroes reveals the emptiness, lack of direction or meaning in life and the mediocrity of modern man's existence.The structue of Garmendia's novels is an original adaptation of contemporary European and American techniques involving the assumption of reader complicity, simultaneity, interior monologue and cinematics. His style is typified by terseness, an unembellished prose, grotesque imagery and a consistently strong appeal to the senses.Salvador Garmendia's authentic, original and sustained novelistic production has earned him the recognition of critics in bringing the Venezuelan narrative firmly into the mainstream of contemporary literature.As a leader of the Sardio group after the fall of the Marcos Perez Jimenez dictatorship in 1958, Garmendia seeks to create a novel which parallels more adequately Venezuela's entrance into the mainstream of modern life. His influence helps to redefine the Venezuelan narrative by rejecting popular regional and socio-political themes, idealized type characters, primitive structural devices and rhetorical eloquence, la escritura bella