Creep monitoring using permanently installed potential drop sensors

Creep is the primary life limiting mechanism of static high temperature, high pressure power station components. Creep state evaluation is currently achieved by surface inspection of microstructure during infrequent outages; a methodology which is laborious, time consuming and considered inadequate. The objective of this work is to develop a monitoring technique that is capable of on-load creep damage monitoring. A continuous update of component integrity will enable better informed, targeted inspections and outage maintenance providing increased power generation availability. A low-frequency, permanently installed potential drop system has been previously developed and will be the focus of this thesis. The use of a quasi-DC inspection frequency suppresses the influence of the electromagnetic skin effect that would otherwise undermine the stability of the measurement in the ferromagnetic materials of interest; the use of even low frequency measurements allows phase sensitive detection and greatly enhanced noise performance. By permanently installing the electrodes to the surface of the component the resistance measurement is sensitive to strain. A resistance - strain inversion is derived and validated experimentally; the use of the potential drop sensor as a robust, high temperature strain gauge is therefore demonstrated. The strain rate of a component is known to be an expression of the creep state of the component. This concept was adopted to develop an interpretive framework for inferring the creep state of a component. It is possible to monitor the accumulation of creep damage through the symptomatic relative increase in strain rate. By taking the ratio of two orthogonal strain measurements, instability and drift common to both measurements can be effectively eliminated; an important attribute considering the necessity to monitor very low strain rates over decades in time in a harsh environment. A preliminary study of using the potential drop technique for monitoring creep damage at a weld has been conducted. Welds provide a site for preferential creep damage accumulation and therefore will frequently be the life limiting feature of power station components. The potential drop technique will be sensitive to both the localised strain that is understood to act as precursor to creep damage at a weld and also the initiation and growth of a crack. Through the course of this project, two site trials have been conducted in power stations. A measurement system and high temperature hardware that is suitable for the power station environment has been developed. The focus of this thesis is the effective transfer of the technique to industry; the realisation of this is detailed in the final chapter.Open Acces

Entrepreneurial Students at the University of Worcester: Five Case Studies.

Since 2004 the University of Worcester has operated an Enterprise Calendar of events that seek to inform and inspire staff and students to engage in entrepreneurial activities. Over 830 individuals have engaged in our annual Enterprise Festival, Enterprise Training workshops, Business Ideas Competition ('BizCom'), Worcester Innovators Network ('WIN') – our student enterprise society – and Student Placements for Entrepreneurs in Education ('SPEED'). All of these activities have been funded by the Higher Education Funding Council for England through their Higher Education Innovation Fund. These case studies consider the effect and impact of this programme of support upon a diverse selection of entrepreneurial students

Accessibility for All: The Australian Experience

development of National Standards under the Disability Discrimination Act of 1992 (DDA). The Standards will guide the implementation of an accessible public transport system in Australia. People with physical disabilities have been denied access to public transport in Australia and have had as a replacement segregated, purpose-built \u27taxi services\u27. These taxi services have been limited in numbers and generally been under resourced, therefore have been unable to provide an equivalent means of transport to that which the general public enjoy. This is now changing and is the result of disability activists lodging successful claims to the Human Rights and Equal Opportunity Commission (HREOC), claiming discrimination under the DDA. As a direct result of \u27Landmark Decisions\u27 and Conciliated Agreements that have been negotiated within these Hearings, State and Federal transport Departments are developing integrated transport systems. A set of National Standards and Guidelines have been developed under the direction of the Australian Transport Council (ATC) to assist in the implementation of accessible transport. In June 1996 these Standards were approved by the ATC as a \u27technically feasible\u27 way of making public transport accessible and were then subjected to a Regulatory Impact. The development of this regulatory legislation has been frustratingly slow and not without issue. This information paper will outline the significant events from the perspective of a person with a disability who has been directly involved in the process. It also highlights the need for all stakeholders to work through this collaboratively rather than aggressively or defensively

Explaining the Early Exit of Eta Carinae from its 2009 X-Ray Minimum with the Accretion Model

We use the accretion model to explain the early exit of Eta Carinae from its 2009 X-ray minimum. In the accretion model the secondary star accretes mass from the primary wind near periastron passage, a process that suppresses the secondary wind. As the shocked secondary wind is responsible for most of the X-ray emission, the accretion process accounts for the X-ray minimum. The early exit from the 2009 X-ray minimum after four weeks, instead of ten weeks as in the two previous minima, is attributed to the primary wind that during the last minimum was somewhat faster and of lower mass loss rate than during the two previous X-ray minima. This results in a much lower mass accretion rate during the X-ray minimum. We show that using fluctuations in these quantities that are within the range deduced from fluctuations in the X-ray flux outside the minimum, can account for the short duration of the last X-ray minimum. The shorter X-ray minimum may have further implications on the recovery of the system from the spectroscopic event.Comment: ApJ Letters, 5 pages, 1 figur

Deconstructing and Reconstructing Rights for Immigrant Children

Children rights advocates and scholars alike continue to call for the development of innovative and alternative rights models, which specifically provide for an expansive conceptualization of children’s rights. Central to their calls for reform is a simultaneous recognition that children’s rights must embody agency – a child’s voice (a proxy for autonomy) – free from governmental interference, as well as the establishment of certain fundamental “needs” that place an affirmative obligation on the State to ensure the child has, and affirmatively provide, when necessary. Reimagining children’s rights also requires reforming our laws in such a way that reflects children as inimitable rights holders possessing unique positive rights. Yet, in U.S. immigration law, children are still most often seen as illegal migrants and their status as alien is continually prioritized over their status as children. With a few notable exceptions, immigration law has been stagnant to adopt dynamic models that incorporate rights models that are informed by the developmental needs of children. This Article contributes to the much-needed discourse about how children’s rights should be understood and realized in immigration law. Unlike other areas of the law, U.S. immigration law still affords no legal distinction between children and adults when adjudicating potential forms of relief. Procedurally there are no compulsory child specific accommodations for immigrant children, as there are in family or juvenile court. Moreover, children are held to the same credibility and evidentiary burdens as adults. This Article concludes that international human rights law, specifically the Convention on the Rights of the Child, articulates a workable, comprehensive, framework of children’s positive (or welfare) and liberal rights that can and should be implemented in U.S. immigration law. Specifically, immigration law must at a minimum prohibit the return of a child to a country where the child would face irreparable harm; permit children when appropriate to petition for immigration relief on their own behalf; provide experts trained in child welfare and immigration law to assess the best interests of the child; and provide free legal counsel to children facing deportation

My Turn: Halting Refugee Admissions is Misguided

Article excerpt: In the aftermath of terrorist attacks in Paris, state governors from more than 25 states, including the governor of my state, New Hampshire, have stated that they are shutting down their borders and not allowing Syrian refugees to live in their states. While their pronouncements carry no legal weight, because state governors don’t have the authority to decide whether to admit refugees into the United States (that is the president’s prerogative), they are misguided and morally reprehensible