Leger est aprendre mes fort est arendre;: Wool, Debt and the Dispersal of Pipewell Abbey (1280 - 1330)

has long been known that English Cistercian monasteries often sold their wool in advance to foreign merchants in the late thirteenth century. The abbey of Pipewell in Northamptonshire features in a number of such contracts with Cahorsin merchants. This paper looks again at these contracts in the context of over 200 other such agreements found in the governmental records. Why did Pipewell descend into penury over this fifty year period? This case study demonstrates that the promise of ready cash for their most valuable commodity led such abbots to make ambitious agreements – taking on yet more debt to service existing creditors - that would lead to their eventual bankruptcy.

Advance Contracts for the Sale of Wool in Medieval England; An Undeveloped and Inefficient Market?

While it is commonly believed that derivative instruments are a recent invention, we document the existence of forward contracts for the sale of wool in medieval England around 700 years ago. The contracts were generally entered into by English monasteries, who frequently sold their wool for up to twenty years in advance to mostly foreign and particularly Italian merchants. Employing a unique source of data collected by hand from the historical records, we determine the interest rates implied in these transactions and we also examine the efficiency of the forward and spot markets. The calculated interest rates average around 20%, in accordance with available information concerning the interest rates used in other types of transactions at that time. Perhaps surprisingly, we also find little evidence of informational inefficiencies in these markets.Wood market, forward contracts, market efficinecy, Medieval England, Interest rates

Interest rates and efficiency in medieval wool forward contracts

Abstract While it is commonly believed that derivative instruments are a recent invention, we document the existence of forward contracts for the sale of wool in medieval England around 700 years ago. The contracts were generally entered into by English monasteries, who frequently sold their wool for up to twenty years in advance to mostly foreign and particularly Italian merchants. Employing a unique source of data collected by hand from the historical records, we determine the interest rates implied in these transactions and we also examine the efficiency of the forward and spot markets. The calculated interest rates average around 20%, in accordance with available information concerning the interest rates used in other types of transactions at that time. Perhaps surprisingly, we also find little evidence of informational inefficiencies in these markets

‘Leger est aprendre mes fort est arendre’: wool, debt, and the dispersal of Pipewell Abbey (1280-1330)

It has long been known that English Cistercian monasteries often sold their wool in advance to foreign merchants in the late thirteenth century. The abbey of Pipewell in Northamptonshire features in a number of such contracts with Cahorsin merchants. This paper looks again at these contracts in the context of over 200 other such agreements found in the governmental records. Why did Pipewell descend into penury over this fifty year period? This case study demonstrates that the promise of ready cash for their most valuable commodity led such abbots to make ambitious agreements – taking on yet more debt to service existing creditors – that would lead to their eventual bankruptcy

Determining the crystallographic orientation of hexagonal crystal structure materials with surface acoustic wave velocity measurements

© 2020 Throughout our engineered environment, many materials exhibit a crystalline lattice structure. The orientation of such lattices is crucial in determining functional properties of these structures, including elasticity and magnetism. Hence, tools for determining orientation are highly sought after. Surface acoustic wave velocities in multiple directions can not only highlight the microstructure contrast, but also determine the crystallographic orientation by comparison to a pre-calculated velocity model. This approach has been widely used for the recovery of orientation in cubic materials, with accurate results. However, there is a demand to probe the microstructure in anisotropic crystals - such as hexagonal close packed titanium. Uniquely, hexagonal structure materials exhibit transverse isotropic linear elasticity. In this work, both experimental and simulation results are used to study the discrete effects of both experimental parameters and varying lattice anisotropy across the orientation space, on orientation determination accuracy. Results summarise the theoretical and practical limits of hexagonal orientation determination by linear SAW measurements. Experimental results from a polycrystalline titanium specimen, obtained by electron back scatter diffraction and spatially resolved acoustic spectroscopy show good agreement (errors of ϕ1=5.14° and Φ=6.99°). Experimental errors are in accordance with those suggested by simulation, according to the experimental parameters. Further experimental results demonstrate dramatically improved orientation results (Φ erro

Spatially resolved acoustic spectroscopy (SRAS) microstructural imaging

© 2019 Author(s). Spatially resolved acoustic spectroscopy (SRAS) is an acoustic microscopy technique that can image the microstructure and measure the crystallographic orientation of grains or crystals in the material. It works by measuring the velocity of surface acoustic waves (SAWs) via the acoustic spectrum. In the usual configuration, the SAWs are generated by laser using a pattern of lines and detected by laser at a point close to this grating-like source. The use of the acoustic spectrum as a means of measuring the velocity has a number of practical advantages which makes the technique robust and fast and gives good spatial resolution. This makes the measurement suitable for imaging and gives it many advantages over traditional laser UT and microstructural measurement techniques. As SRAS is a laser ultrasound testing technique (LUT) which can be applied to a wide range of industrially relevant samples as a non-destructive evaluation technique. There are no size limitations on the samples that can be imaged and the surface preparation required is significantly more relaxed than many other techniques with the capability of operating on many as manufactured finishes. This permits the use of SRAS as an online inspection tool, for instance during additive or subtractive manufacturing, as a QA tool during manufacture or as an NDE/T tool in service

Spatially resolved acoustic spectroscopy for integrity assessment in wire-arc additive manufacturing

Wire–arc additive manufacturing (WAAM) is an emergent method for the production and repair of high value components. Introduction of plastic strain by inter-pass rolling has been shown to produce grain refinement and improve mechanical properties, however suitable quality control techniques are required to demonstrate the refinement non-destructively. This work proposes a method for rapid microstructural assessment of Ti–6Al–4V, with limited intervention, by measuring an acoustic wave generated on the surface of the specimens. Specifically, undeformed and rolled specimens have been analysed by spatially resolved acoustic spectroscopy (SRAS), allowing the efficacy of the rolling process to be observed in velocity maps. The work has three primary outcomes (i) differentiation of texture due to rolling force, (ii) understanding the acoustic wave velocity response in the textured material including the underlying crystallography, (iii) extraction of an additional build metric such as layer height from acoustic maps and further useful material information such as minimum stiffness direction. Variations in acoustic response due to grain refinement and crystallographic orientation have been explored. It has been found that the limited α-variants which develop within prior-β grains lead to distinctive acoustic slowness surfaces. This allowed prior-β grains to be resolved. A basic algorithm has been proposed for the automated measurement, which could be used for in-line closed loop control. The practicality and challenges of applying this approach in-line with fabrication are also discussed

Spatially resolved acoustic spectroscopy for texture imaging in powder bed fusion nickel superalloys

© 2019 Author(s). There is a clear industrial pull to fabricate high value components using premium high temperature aerospace materials by additive manufacturing. Inconveniently, the same material properties which allow them to perform well in service render them difficult to process via powder bed fusion. Current build systems are charac-terised by high defect rates and erratic microstructure, leading to components with inferior mechanical properties. The work presents microstructural texture imaging of powder-bed fusion components by a non-contact laser ultrasonic method, Spatially Resolved Acoustic Spectroscopy (SRAS). In short, this work demonstrates the ability to SRAS to detect and characterise meso-scale crystalline texture features. Probing samples manufactured by powder bed fusion, in the common nickel based aerospace superalloy Inconel 718, it has been shown the the primary crystalline orientation of can be inferred from the measured velocity, with good agreement with Electron Backscatter Diffraction. The studied sample was found to have a microstructure formation that bore a heavy resemblance to the chosen scanning pattern, with clear influence from the geometry through varying scan vector length and island-boundary scan strategy. This work forms part of a progression towards deployment of a SRAS system as an in-situ inspection solution for PBF