Performing public credit at the eighteenth-century Bank of England

Much is known about the negotiation of personal credit relationships during the eighteenth century. It has been noted how direct contact and observation allowed individuals to assess the creditworthiness of those with whom they had financial connections and to whom they might lend money. Much less is known about one of the most important credit relationships of the long eighteenth century: that between the state and its creditors. This article shows that investors could experience the performance of public credit at the Bank of England. By 1760 the Bank was the manager of nearly three-quarters of the state's debt and housed the main secondary market in that debt. Thus, it provided a place for public creditors, both current and potential, to attend and scrutinize the performance of the state's promises. The article demonstrates how the Bank acted to embody public credit through its architecture, internal structures, and imagery and through the very visible actions of its clerks and the technologies that they used to record ownership and transfer of the national debt. The Bank of England, by those means, allowed creditors to interrogate the financial stability and reputation of the state in the same ways that they could interrogate the integrity of a private debtor.Peer reviewedFinal Accepted Versio

New records of Tephritidae (Diptera) from Great Smoky Mountains National Park - 2

Thirty additional species of tephritid flies (Diptera: Tephritidae) from Great Smoky Mountains National Park (GSMNP), including historical records, are presented together with information on host(s), if known, distributions, and life histories. This brings the total number of tephritid flies recorded from GSMNP to 46

Effects of Boundary-Layer Ingestion on the Aero-Acoustics of Transonic Fan Rotors

The use of boundary-layer-ingesting, embedded propulsion systems can result in inlet flow distortions where the interaction of the boundary-layer vorticity and the inlet lip causes horseshoe vortex formation and the ingestion of streamwise vortices into the inlet. A previously-developed body-force-based fan modeling approach was used to assess the change in fan rotor shock noise generation and propagation in a boundary-layer-ingesting, serpentine inlet. This approach is employed here in a parametric study to assess the effects of inlet geometry parameters (offset-to-diameter ratio and downstream-toupstream area ratio) on flow distortion and rotor shock noise. Mechanisms related to the vortical inlet structures were found to govern changes in the rotor shock noise generation and propagation. The vortex whose circulation is in the opposite direction to the fan rotation (counter-swirling vortex) increases incidence angles on the fan blades near the tip, enhancing noise generation. The vortex with circulation in the direction of fan rotation (co-swirling vortex) creates a region of subsonic relative flow near the blade tip radius that decreases the sound power propagated to the far-field. The parametric study revealed that the overall sound power level at the fan leading edge is set by the ingested streamwise circulation, and that for inlet designs in which the streamwise vortices are displaced away from the duct wall, the sound power at the upstream inlet plane increased by as much as 9 dB. By comparing the far-field noise results obtained to those for a conventional inlet, it is deduced that the changes in rotor shock noise are predominantly due to the ingestion of streamwise vorticity

An Investigation of Nonlinear Flow Oscillations in a High-Pressure Centrifugal Pump

High-pressure multistage pumps and their coupled piping systems, typically used in the process and power generation industry, can experience dangerous system-level instabilities. This can occur at flow coefficients well away from the surge limit and in the absence of cavitation. Such a pumping system and a related new kind of instability are the focus of this paper. A system-wide instability was observed at 0.05 times rotor frequency for flow coefficients near maximum head rise but at negative slope, thus on the stable side of the head rise characteristic. A previous study based on system-level experiments concluded that this instability differs from classical surge, cavitation surge, rotating stall, and rotating cavitation, but the underlying mechanism and necessary flow conditions remain unknown. This paper investigates the root cause of the system-wide pump instability, employing a systematic analysis of the impact of geometry changes on pump stability and performance. It is found that the upstream influence of the unsteady flow separation in the return channel leads to a time-varying incidence angle change on the volute tongue which causes periodic ingestion of low-stagnation pressure fluid into the diffuser passages. This sets up a limit cycle, promoting the system-wide instability. With the instability mechanism determined, the pump is redesigned to remove the flow separation while maintaining performance at design conditions. Unsteady numerical simulations demonstrate improved efficiency and pressure recovery at low flow coefficients. A time accurate calculation also indicates stable operation at all relevant flow conditions. The paper resolves a long-standing pump stability problem and provides design guidelines for reliable and improved performance, important to the chemical processing and power generation industry

Creating the dream team: introducing participatory sports and exercise medicine via 'Patient Voices'.

No abstract

Flyer by Night: A Cautionary Review

Review of Bio-rhythms, Biological Clocks and Periodicity: Index of New Information with Authors & Subjects by Preston G. Parke. ABBE Publishers Association of Washington, D.C. Washington, D.C. 1996. $49.50. The flyer piqued our interest: a hot topic that students were trying to find pre-packaged for their reports and essays. One hundred and sixty pages full of the most recent articles on bio-rhythms -- with index. A reasonable price, for this day, was demanded. The book was ordered, cataloged, prepped and placed on the new books for reference truck. Twenty minutes later, the book had been withdrawn and a note made in the accession records to never purchase from the publisher again. We had been burned by a vanity press