Jonathan R Wood | University College London (original) (raw)

Archaeology by Jonathan R Wood

Melammu Workshops and Monographs 10, 2024

This paper presents the evidence underpinning a recently developed hypothesis concerning the tran... more This paper presents the evidence underpinning a recently developed hypothesis concerning the transfer of metal smelting technology from the Eastern Mediterranean to Iberia, beyond the Straits of Gibraltar, in the earliest Iron Age (Wood et al., 2019) and the role Phoenicians and Cyprus may have played in the transmission of this know-how (Wood et al., 2020). It is generally agreed that the ancient metallurgists that first smelted and cupellated argentiferous jarositic ores in Iberia were non-local agents and that this did not take place before a Phoenician footprint was established there (Hunt Ortiz, 2003). Indeed, Craddock (2014) has suggested that the great achievement of the Phoenicians was to discover jarosite’s potential and to develop ways of successfully smelting it. This paper presents the hypothesis that Cyprus played an integral role in this technology transfer from east to west.

Archaeological and Anthropological Sciences, 2024

Compositional data, which have relative rather than absolute meaning, are common in quantitative ... more Compositional data, which have relative rather than absolute meaning, are common in quantitative archaeological research.
Such multivariate data are usually expressed as proportions, summing to 1, or equivalently as percentages. We present a comprehensive and defensible workflow for processing compositional data in archaeometry, using both the original compositional
values and their transformation to logratios. The most useful logratio transformations are illustrated and how they affect the
interpretation of the final results in the context of both unsupervised and supervised learning. The workflow is demonstrated
on compositional data from bronze ritual vessels to provide compositional fingerprints for the Shang and Zhou periods of the
Chinese Bronze Age. Predictions, with caveats, of the fabrication age of the vessels are made from the compositional data –
in effect, compositional rather than typological seriation of the bronzes. In the Supplementary Material, we further explore
the effect of zeros in the dataset and compare logratio analyses with the chiPower approach, where we replace any value in
the original data determined as being below the detection limit of the instruments for the element, with zeros. The data and
R code for reproducing all the analyses are provided both in the Supplementary Information and online.

Oxbow, 2024

Wood, J.R. 2023 'Identifying episodes of recycling in the archaeological record' in I. Bavuso, G.... more Wood, J.R. 2023 'Identifying episodes of recycling in the archaeological record' in I. Bavuso, G. Furlan, E.E. Intagliata and J. Steding (eds) Economic Circularity in the Roman and Early Medieval Worlds: New perspectives on invisible agents and dynamics, Oxbow Books.

Internet Archaeology, 2023

Wood, J.R., Ponting, M. and Butcher, K. 2023 'Response to comment of Albarède and colleagues', In... more Wood, J.R., Ponting, M. and Butcher, K. 2023 'Response to comment of Albarède and colleagues', Internet Archaeology 61. https://doi.org/10.11141/ia.61.10.response

Internet Archaeology, 2023

Although silver coins have been investigated through the lens of geological provenance to locate ... more Although silver coins have been investigated through the lens of geological provenance to locate argentiferous ore deposits exploited in their production, we consider that this avenue of research may be a cul-de-sac, especially for studies that rely heavily on deciphering lead and silver isotope signatures that may have been altered by the addition of lead and copper (and their associated impurities) during silver refining and debasement, and by ancient recycling of coinage. Instead, we focus our attention on mints, by analysing the compositions of over 1000 silver coins from the early 1st century BC to AD 100. We propose that lead from the west Mediterranean was used exclusively to refine silver at mints in the West, and that an unknown lead supply (possibly from Macedonia), used in the East by the Late Seleucid ruler Philip I Philadelphus and later Mark Antony, was mixed with western lead. Extensive mixing of lead and/or silver coins is particularly evident under Nero and Vespasian, aligning with historically attested periods of recycling following currency reform. We further propose that coins minted in the kingdom of Mauretania used different lead and silver sources from the majority of coins minted in the western Mediterranean, and that silver coins minted at Tyre are derived from silver refined in the west Mediterranean. Coinage minted at Alexandria is consistent with debasement of recycled Roman denarii, thereby suggesting that denarii were deliberately removed from circulation to mint tetradrachms during the early Imperial Roman period.

Archaeological and Anthropological Sciences, 2023

Dated measurements of lead pollution in deep Greenland ice have become a useful proxy to monitor ... more Dated measurements of lead pollution in deep Greenland ice have become a useful proxy to monitor historical events because interruptions in lead-silver production result in fluctuations in lead emissions. However, the application of the lead emission record has not perhaps received the attention it deserves because of the difficulty in connecting macroscale events, such as wars and plagues, to their economic repercussions. For instance, although debasement of silver coinage with copper has been proposed as a reasonable response to interruptions in silver production, reductions in fineness of the silver denarius, the backbone of Roman coinage from the late third century BC, are not always coincident with decreases in lead deposited in Greenland. We propose that extensive recycling of silver that is evident in the numismatic record can better explain drops in lead emissions and, thereby, the responses to major historical events, such as warfare in the silver-producing areas of the Iberian Peninsula and southern France during the middle and late Roman Republic.

Archaeometry, 2022

Although the birth of Classical Greece is often attributed to the constitutional reforms of Cleis... more Although the birth of Classical Greece is often attributed to the constitutional reforms of Cleisthenes (508/507 BCE), the achievement of an economically minded government under the Peisistratid tyrant Hippias (527-510 BCE) potentially paved the way by advancing Athenian silver for exportation in international trade. It is proposed here that new silver technology, which initiated the transition from acquiring silver from 'dry' silver ores to silver-bearing lead ores, was introduced to Greece during the time of the Peisistratids (561-510 BCE). Massive exploitation of silver-bearing lead ores at Laurion in Attica, which later financed the construction of a war navy, appears evident in the lead pollution records of Greenland ice, lead isotopic analyses of sixth-century BCE Attic silver coins and late Iron Age Levantine hacksilver, and is reflected in the numbers of lead votive figurines at sanctuaries in Sparta. Against the backdrop of the threat of war with Persia and an imminent Spartan invasion which resulted in the overthrow of Hippias (510 BCE), it is considered that a political transition occurred because Greece was both geologically and politically disposed to adopt this labour-intensive silver technology which helped to initiate, fund and protect the radical social experiment that became known as Classical Greece.

Journal of Archaeological Method and Theory, 2022

Research into ancient Chinese metallurgy has flourished over recent years with the accumulation o... more Research into ancient Chinese metallurgy has flourished over recent years with the accumulation of analytical data reflecting the needs of so many archaeological finds. However, the relationship between technology and society is unlikely to be revealed simply by analysing more artefacts. This is particularly evident in the debates over the sources of metals used to manufacture the Chinese ritual bronzes of the Shang (c. 1500-1046 BCE), Western Zhou (c. 1046–771 BCE) and Eastern Zhou (c. 771–256 BCE) dynasties. This article recognises that approaches to analytical data often fail to provide robust platforms from which to investigate metallurgical technology within its wider social and cultural contexts. To address this issue, a recently developed multivariate approach is applied to over 300 Chinese ritual bronzes from legacy data sets and nearly 100 unearthed copper-based objects from Anyang and Hanzhong. Unlike previous investigations that have relied predominantly on interpreting lead isotope signatures, the compositional analyses presented here indicate that copper and lead used to manufacture the bronzes are derived from mining progressively deeper ores in the same deposits rather than seeking out new sources. It is proposed that interpretations of social, cultural and technological change predicated on the acquisition of metals from disparate regions during the Chinese Bronze Age may need to be revised.

Archaeometry, 2022

Any archaeological artefact made from recyclable material may have been recycled before depositio... more Any archaeological artefact made from recyclable material may have been recycled before deposition. Three approaches are presented which have identified recycling in the archaeological record: (1) the application of log ratio analyses to investigate compositional data indicates that Roman glass was recycled and reapplied as a glaze on Parthian pottery, thereby suggesting that the paucity of Parthian and Sasanian glass in the archaeological record is due to recycling; (2) linear mixing lines on plots that combine compositional and isotopic data suggest that most silver found in the Iron Age hoards of the southern Levant was mixed, with vertical mixing lines indicating that some of it was melted down hastily in times of unrest; and (3) histograms of compositional data provide evidence of recycling accompanied by dilution of cobalt-blue glass in New Kingdom Egypt, potentially because the colourant was not available in later periods, thereby questioning the accepted provenance of the cobalt source. It is considered that application of these approaches can contribute to a better understanding of the motivations behind recycling in prehistory.

Internet Archaeology, 2021

Silver-bearing lead ores at Laurion in Attica were considered to have been first exploited with t... more Silver-bearing lead ores at Laurion in Attica were considered to have been first exploited with the introduction of coinage sometime around the birth of Classical Greece. However, in the late 20th century this chronology was radically revised earlier, to the Bronze Age, largely supported by lead isotope analyses (LIA). Here, we acknowledge that lead and silver metallurgy emerged from the earliest times but we propose that any correlation between these metals in the archaeological record is not a consequence of a geological association between lead and silver in ores such as galena until the middle of the first millennium BCE. We suggest that ancient metallurgists recognised that silver minerals (such as horn silver) dispersed in host rocks could be concentrated in molten lead and that LIA signatures of Bronze Age silver artefacts reflect the use of exogenous lead to extract silver, perhaps applying processes similar to those used to acquire silver in Bronze Age Siphnos. We further propose that lead from Laurion used for silver extraction resulted in the inadvertent transfer of its LIA signature (probably aided by roving silver prospectors) to silver objects and metallurgical debris recovered around the Aegean. New compositional analyses for the Mycenaean shaft-grave silver (c. 1600 BCE) support these conclusions. We believe that reverting to the mid-first millennium BCE for the first exploitation of silver from argentiferous lead ores is consistent with the absence of archaeological evidence for centralised control over Laurion until the Archaic period, the paucity of lead slag associated with silver-processing debris at Bronze Age sites, the scarcity of silver artefacts recovered in post-shaft grave contexts at Mycenae and throughout the Early Iron Age Aegean, the few Attic silver coins with LIA signatures consistent with Laurion until after 500 BCE and a single unambiguous mention of silver in the Linear B texts.

Archaeological and Anthropological Sciences, 2021

Chemical compositional data sets of archaeological artefacts are often analysed using standard st... more Chemical compositional data sets of archaeological artefacts are often analysed using standard statistical procedures. Adopting a different approach, we examine the major element oxides found in Parthian and Sasanian glazed pottery by identifying statistically important ratios of oxides in conjunction with the expert knowledge of the archaeological scientist during, rather than after, the identification process. This results in meaningful ratios, both statistically and archaeologically, which help identify the recipes and production practices used by Mesopotamian glass and glaze producers. The application of logratio analysis to interrogate the chronological groups suggests that the silica sources used for glazes were significantly purer in later periods and exhibited less variation. Comparing the expert-assisted selection of ratios derived from a legacy data set to the ratios from compositional data of Parthian glazed pottery recovered at the early 3rd century CE Roman military outpost of Ain Sinu in northern Iraq supports the hypothesis that there was a shift to more standardised recipes in the production of glass used for glazes. If this translates to a centralised glass-making industry, it would suggest that there are, as yet, undiscovered glass production centres, potentially in areas associated with increased urbanisation in southern Mesopotamia around the time of the Parthian–Sasanian transition.

IRAQ, 2020

Alkaline glazes were first used on clay-based ceramics in Mesopotamia around 1500 B.C., at the sa... more Alkaline glazes were first used on clay-based ceramics in Mesopotamia around 1500 B.C., at the same time as the appearance of glass vessels. The Roman Empire used lead-based glazes, with alkaline natron glass being used only to produce objects of glass. Chemical analysis has had some success determining compositional groups for Roman/Byzantine/early Islamic glasses because of the discovery of major production sites. Parthian and Sasanian glass and glazed wares, however, have been found only in consumption assemblages, which have failed to inform on how they were made. Here we reanalyse compositional data for Parthian and Sasanian glazes and present new analyses for Parthian glazed pottery excavated at the early third century A.D. Roman military outpost of Ain Sinu in northern Iraq. We show that some Parthian glazes are from a different tradition to typical Mesopotamian glazes and have compositions similar to Roman glass. We propose that Roman glass was recycled by Parthian potters, thereby suggesting that as yet undiscovered Mesopotamian glass production centres ordinarily supplied glass for indigenous glazed pottery. Furthermore, if recycling glass to make glazed pottery was extended to indigenous glassware, this may provide an explanation for the paucity of Parthian and Sasanian glass in the archaeological record.

Journal of Eastern Mediterranean Archaeology and Heritage Studies, 2020

open access at : https://www.jstor.org/stable/10.5325/jeasmedarcherstu.8.1.0001 A recent re... more open access at : https://www.jstor.org/stable/10.5325/jeasmedarcherstu.8.1.0001

A recent reanalysis of compositional and lead isotope legacy data from the early silver hoards of the southern Levant (ca. twelfth–ninth centuries BCE) identified that not only was most of this hacksilver mixed but that it probably derived from the Pyritic belt of southern Iberia, the Taurus mountains in Anatolia, and a third unknown source. We propose that the unknown component of Tel Dor’s hacksilver was silver potentially derived from ores mined at Kalavasos on Cyprus. The presence of Cypriot silver in the southern Levant complements finds of Phoenician pottery on Cyprus, supporting that there was continuity of trade from the end of the Bronze Age to the beginning of the Iron Age between Cyprus and the Levant. Furthermore, our findings suggest that the technology required to smelt and cupellate argentiferous jarosite ores was first practiced on Cyprus prior to risky and costly ventures to Iberia.

keywords: Tel Dor, silver, jarosite, Phoenicians, mixing lines, lead isotopes

Trabajos de Prehistoria, 2019

A fragment of a silver ingot recovered from the Phoeni-cian settlement of La Rebanadilla, near Ma... more A fragment of a silver ingot recovered from the Phoeni-cian settlement of La Rebanadilla, near Malaga, in southeast Iberia has been investigated using lead isotope and compo-sitional analyses. The ingot, which was found at the lowest levels of the site, potentially dates from 11 th-9 th century BC, placing it alongside the hoards of hacksilver found in the southern Levant in terms of chronology. The Pb crustal age (from lead isotope data) and compositional data support that the ingot derives from Hercynian-age ores with high bismuth concentrations. This signature is consistent with the Pyritic belt of southwest Iberia, particularly around the ancient mining areas of Riotinto. It is proposed that the silver for this ingot was extracted from jarosite ores at Riotinto, where it was coarsely refined through cupellation into an ingot still retaining high levels of lead, before being transported to La Rebanadilla, which was a potential point of departure back to the Phoenician homeland. The significance of transporting silver in a form which would have required further refining is discussed in relation to the movement of silver by the Phoenicians in the Iron Age Mediterranean. A new mechanism is proposed to explain the elusive nature of Iberian silver in the archaeological record.

RESUMEN Un fragmento de lingote de plata descubierto reciente-mente en el yacimiento fenicio de La Rebanadilla (Málaga) ha sido investigado mediante isotopos de plomo y análisis elemental. El lingote recuperado en los niveles inferiores del yacimiento, se fecha potencialmente entre fines del siglo XI y el IX a. C., situándose en cronología similar a algunos depósitos de hacksilver del área del levante mediterráneo. La edad de la corteza calculada a partir de los isotopos de plomo y la composición señalan que el lingote fue obtenido de minerales de Edad Hercínica con concentraciones altas de bismuto. Esta signatura es compatible con la de la Faja Pirítica del suroeste de la península ibérica, en particular con la de las antiguas minas de la zona de Riotinto. Se propone que la plata de este lingote fue obtenida de las jarositas argentíferas de Riotinto, donde sufrió solo un primer refinado mediante copelación, conservando un alto con-tenido en plomo antes de ser comercializado hacia La Re-banadilla, que pudo ser un lugar potencial para su transporte hacia los territorios fenicios en el Mediterráneo oriental. Las implicaciones del transporte de plata sin refi-nar son discutidas en relación al comercio de la plata por los fenicios durante la Edad del Hierro en el Mediterráneo y la dificultad de identificar la plata ibérica en el registro arqueológico.

Internet Archaeology, 2019

A recent compositional study of Egyptian cobalt-blue glass from museum collections in Japan (18th... more A recent compositional study of
Egyptian cobalt-blue glass from
museum collections in Japan
(18th Dynasty) and from the
site of Dahshur (18th and 19th-
20th Dynasties) concluded that
a new source of cobalt was
exploited for the later Dahshur
glass, thereby suggesting that
glass production continued into
the Ramesside period (Abe et
al. 2012). It is shown in the current article that some of this 18th Dynasty glass
and the majority of the 19th-20th Dynasty glass had been recycled, not only
supporting the general consensus that glass production virtually disappeared by 1250 BC, but that the cobalt source did not necessarily change. It is further
proposed, however, that the generally accepted cobalt source for Egyptian glass
was not the alum deposits of Egypt's Western Desert, but derived from
cobaltiferous siliceous ores, possibly from central Iran.
Re-analysis of the compositions of cobalt-blue glass frit found at Amarna, as well
as Egyptian and Mesopotamian glass, suggests that the cobalt colourant was a byproduct
of silver extraction from these ores and can therefore be considered as a
concentrated cobalt glass slag, which travelled in the form of a frit to glass
producers who added it to locally derived base glasses and/or their precursors.
Experiments conducted on ore containing cobalt-nickel arsenides with native silver
demonstrate that not only can silver be extracted and that concentrated cobalt
glass can be produced simply by adding a flux, but that some components of the
ore partition preferentially into the silver or the glass slag, thereby weakening
their associations with the other components in archaeological glass. Treating the
cobalt-blue colourant as a slag composed of the gangue of a smelting system
provides an explanation for the unique elevated levels of alumina and lower levels
of potash found in cobalt-blue glasses, as well as providing an explanation for the
cessation of cobalt exploitation at the end of the Late Bronze Age. It is suggested
that the exhaustion of native silver and siliceous silver ore deposits during the
Bronze Age, with argentiferous lead ores becoming the main source of silver,
depleted the amount of cobalt available, thereby reducing the amount of glass
produced which, in turn, led to increases in recycling during the New Kingdom
period.

Journal of World Prehistory, 2019

The origins of the silver trade across the Mediterranean, and the role of the Phoeni - cians in t... more The origins of the silver trade across the Mediterranean, and the role of the Phoeni
-
cians in this phenomenon, remain contentious. This is partly because of difficulties
encountered when trying to assign archaeological silver to its geological sources.
Here we present a reanalysis of Iron Age silver hoards in the southern Levant, which
demonstrates not only that recycling of silver was widespread in the Early and Late
Iron Age, but that the components of this mixed silver originated from the Aegean,
Anatolia and the western Mediterranean. An assessment of lead isotope analyses
combined with compositional data allows the identification of mixing lines based
on gold levels in the silver and the Pb crustal age (or, more loosely, geological age)
of the ore from which the silver originated. It is shown that, from as early as the
11th century BC, these mixed silver signatures derive from the Taurus mountains in
Anatolia, from Iberia and an unknown source—with Sardinia as an additional pos
-
sibility—and Laurion in Greece in the Late Iron Age. In contrast to copper, which
was deliberately alloyed with silver, gold appears to have been mixed unintention
-
ally, through the melting down of silver objects with gold parts. It is suggested that
vertical mixing lines
(with constant Pb crustal age but variable Au), may indicate
the melting down and mixing of silver in times of unrest, both here and in other
contexts. Gold and lead concentrations in the silver indicate that native silver from
Iberia was most likely used in the Early Iron Age, suggesting that the first people to
convey silver to the southern Levant were not miners but traders who had acquired
silver directly from the indigenous Bronze Age inhabitants of Iberia. However, evi
-
dence of the exploitation of jarosite also supports that silver ore mining and cupel
-
lation was ongoing in Iberia at a similar time, and continued in the Late Iron Age—
potentially a result of technological transfer from the East. In essence, the western
Mediterranean origin of the silver in these Early Iron Age southern Levantine hoards
supports an emerging picture of Mediterranean interactions and trade relations in
the increasingly
bright
Dark Ages (c. 1200–800 BC).

We present a detailed response to Professor Pernicka's critique of our paper entitled " Iridium t... more We present a detailed response to Professor Pernicka's critique of our paper entitled " Iridium to provenance ancient silver ". We have concluded that Pernicka's hypothesis, which suggests that elevated levels of iridium in ancient silver artefacts is a consequence of silver deriving from the cementation (parting) process, does not account for the available evidence and that his critiques of the analyses we presented seem misplaced. We offer a simpler solution and show that the structure of our transformed data is founded on logical reasoning which is borne out by the empirical results. Essentially, this response supports our view reported in the original paper that the variation in iridium in ancient silver is largely geological rather than a consequence of de-silvering gold.

Trace levels of iridium in ancient silver artefacts can provide information on the sources of sil... more Trace levels of iridium in ancient silver artefacts can provide information on the sources of silver-bearing ores as well as the technologies used to extract silver. A geographically and chronologically disparate legacy dataset, comprised of Near Eastern objects from the Sasanian and Byzantine Empires (1st Millennium AD) and coins circulating around the Mediterranean in the mid-1st Millennium BC, shows that Ag-Au-Ir log-ratio plots can help identify silver derived from the same mining areas, as well as broadly differentiating between the ore types exploited. Combining trace element and lead isotope analyses through the Pb crustal age of the ore, further delimits interpretations on the compositions and locations of silver ore sources. Furthermore, it is shown that silver artefacts of Near Eastern origin have exceptionally high iridium levels, suggesting a unique silver-bearing ore source, potentially in the Taurus mountain range of southern Ana-tolia. The wide range of crustal ages identified for ancient Greek coins and Near Eastern objects suggest that the addition of exogenous lead as a silver collector during smelting was common practice in the Near East as early as 475BCE. The practice of mixing silver from different sources has also been identified by triangulating the log-ratio subcomposition plots, Pb crustal ages of the ore from which the silver derived and absolute values of trace levels of gold and iridium in silver artefacts.

Nanotechnology by Jonathan R Wood

The components that contribute to Raman spectral shifts of single-wall carbon nanotubes ͑SWNT's͒ ... more The components that contribute to Raman spectral shifts of single-wall carbon nanotubes ͑SWNT's͒ embedded in polymer systems have been identified. The temperature dependence of the Raman shift can be separated into the temperature dependence of the nanotubes, the cohesive energy density of the polymer, and the buildup of thermal strain. Discounting all components apart from the thermal strain from the Raman shift-temperature data, it is shown that the mechanical response of single-wall carbon nanotubes in tension and compression are identical. The stress-strain response of SWNT's can explain recent experimental data for carbon nanotube-composite systems.

Specific peaks of the Raman spectrum of single-wall nanotubes shift significantly upon immersion ... more Specific peaks of the Raman spectrum of single-wall nanotubes shift significantly upon immersion of the tubes in a liquid, relative to the corresponding peaks in air. This observation means that nanotubes are sensitive to molecular forces, and is interpreted by relating the corresponding molecular strain to a thermodynamic parameter, the cohesive energy density ͑or more loosely, the surface tension͒ for a range of liquids. We find that nanotubes deform by a different amount for each liquid. Calibration of this phenomenon enables the construction of a compressive stress-strain curve for carbon nanotubes.

Melammu Workshops and Monographs 10, 2024

Archaeological and Anthropological Sciences, 2024

Oxbow, 2024

Internet Archaeology, 2023

Archaeological and Anthropological Sciences, 2023

Archaeometry, 2022

Journal of Archaeological Method and Theory, 2022

Archaeometry, 2022

Internet Archaeology, 2021

Archaeological and Anthropological Sciences, 2021

IRAQ, 2020

Journal of Eastern Mediterranean Archaeology and Heritage Studies, 2020

open access at : https://www.jstor.org/stable/10.5325/jeasmedarcherstu.8.1.0001 A recent re... more open access at : https://www.jstor.org/stable/10.5325/jeasmedarcherstu.8.1.0001

keywords: Tel Dor, silver, jarosite, Phoenicians, mixing lines, lead isotopes

Trabajos de Prehistoria, 2019

Internet Archaeology, 2019

Journal of World Prehistory, 2019

Small amounts of single-wall carbon nanotubes embedded in a polymer matrix were used to sense the... more Small amounts of single-wall carbon nanotubes embedded in a polymer matrix were used to sense the mechanical response of the polymer using microRaman spectral data. A flow orientation method was applied to align the nanotubes in the matrix. The Raman spectra obtained for specimens cut both parallel and perpendicular to the flow direction were found to be significantly different, as a function of mechanical strain. Thus Raman spectroscopy combined with mechanical testing provides a way to probe the alignment of nanotubes in composites. The Raman shift-strain response for samples loaded perpendicular to the flow direction suggests that nanotube reorientation is achieved upon straining the polymer beyond its yield point. Our data suggest that the adhesion between the nanotubes and the polymer exceeds the shear yield strength of the matrix. We show that a stress-strain curve for the polymer may be produced directly by means of Raman spectroscopy. ᭧

High hydrostatic pressures were applied to single-wall carbon nanotubes by means of a diamond anv... more High hydrostatic pressures were applied to single-wall carbon nanotubes by means of a diamond anvil cell (DAC), and micro-Raman spectroscopy was simultaneously used to monitor the pressure-induced shift of various nanotube bands. The data confirm recent results independently obtained from internal pressure experiments with various liquids, where the peak shifts were considered to arise from compressive forces imposed by the liquids on the nanotubes. It is also shown that the nanotube peak at 1580 cm -1 (the G band) shifts linearly with pressure up to 20 000 atm and deviates from linearity at higher pressure. This deviation is found to be coincident with a drop in Raman intensity for the disorder-induced peak at 2610 cm -1 (the overtone of the D* band), possibly corresponding to the occurrence of reversible flattening of the nanotubes. The independent results presented here confirm the potential of nanotubes as molecular sensors.

Raman spectral shifts of single-wall carbon nanotubes embedded in polymer systems were used to me... more Raman spectral shifts of single-wall carbon nanotubes embedded in polymer systems were used to measure transitions in polymers. Glass-transition temperatures and secondary transitions were observed, and Raman spectroscopic data were compared with dynamic mechanical tests for a thermosetting and a thermoplastic polymer. The data confirm that the Raman spectral response of carbon nanotubes embedded in polymers is sensitive to polymer transitions.

Raman spectroscopy was used to map the stress distribution in the vicinity of discontinuities in ... more Raman spectroscopy was used to map the stress distribution in the vicinity of discontinuities in a polymer using single-wall nanotubes seeded in the specimen. In the case of a hole in a polymer matrix subjected to unidirectional stress, the experimental stress field compared well with the classical linear elasticity solution. For a single glass fiber embedded in a polymer, the tangential thermal residual stress in the vicinity of the fiber was picked up by Raman spectroscopy and is in satisfactory agreement with a standard two-phase concentric cylinder model.

The changes in Poisson's ratio and longitudinal modulus as a result of transverse ply cracking in... more The changes in Poisson's ratio and longitudinal modulus as a result of transverse ply cracking in simple crosspO" GFRP and CFRP laminates are examined experimentally and theoretically. The results show that at saturation transverse cracking, reductions in Poisson's ratio of about 40 % are obtained in both the GFRP and CFRP systems, while the associated redaction in longitudinal moduhls is much lower (less than 20% in GFRP and less than 5% in CFRP). A simple anaO'tical model is presented, based on an extension of a one-dimensional shear-lag analysis, which predicts the trends of the experimental data sati.~factorily.

Models based on mass diffusion theory successfully represent the growth and collapse of gas bubbl... more Models based on mass diffusion theory successfully represent the growth and collapse of gas bubbles in an epoxy resin. Solution of the steady-state diffusion equations requires measurement of the diffusion coefficient and solubility of the mobile species within the resin pre-cursor. These parameters are affected by changes in temperature and/or pressure and are generally not measured as part of a processing schedule. Models have been evaluated that predict the prerequisite driving force'..in terms of a concentration gradient and the interaction with the processing variables from the chemistry of the resin molecule. A solubility parameter approach has been used to estimate the solubility of gas in the resin in conjunction with regular solution theory. The surface tension forces, which also play an active role in bubble stability and dynamics, have been estimated from molar attraction constants.

Models based on a mass-diffusion theory successfully represent the growth and collapse of gas bub... more Models based on a mass-diffusion theory successfully represent the growth and collapse of gas bubbles in an epoxy resin. A quantitative evaluation of the steady-state diffusion equations requires values for the diffusion coefficient and the solubility of the mobile species within the resin precursor. These parameters are affected by changes in temperature and/or pressure, and they are generally not measured as part of a processing schedule. Models have been evaluated that predict the temperature dependence of the gas diffusion coefficient in the resin. A free volume approach describes the viscosity of the resin successfully at temperatures of up to 100 K above the glass-transition temperature. At higher temperatures, a thermal-energy-barrier approach is more appropriate. A direct correlation between the viscosity of the resin and the gas diffusion coefficient is proposed which is considered to be applicable to any gas/resin system where specific component interactions are negligible and the solute concentration is sufficiently low that it does not affect the free volume of the medium.

The problem of porosity has been addressed in relation to process modelling of composite material... more The problem of porosity has been addressed in relation to process modelling of composite materials. The material and processing inter-relationships, critical to the production of a void-free laminate, have been investigated and it is concluded that entrapped bubbles can be collapsed and growth processes can be suppressed, or totally inactivated, by control of pressure and temperature, the 'principal process variables. As these processes are time-dependent, models based on mass diffusion theory have been developed which predict the rate of growth or collapse of gas bubbles in a resin precursor. Simple experimental methods have been developed to measure the required input parameters for the model and the predictions have been compared with experimental observations.

Mass diffusion theory has been used to predict the rate of growth or collapse of gas bubbles in a... more Mass diffusion theory has been used to predict the rate of growth or collapse of gas bubbles in a resin precursor in order to aid the production of void-free composite materials. Simple models have been successfully compared with experimental data which show that bubble behaviour is influenced by the concentration of mobile species in the bulk resin, the concentration at the bubble/resin interface and the diffusion coefficient of these species in the resin precursor. These parameters are affected by temperature, pressure and the exposure history of the resin. Gas bubbles have been monitored and modelled for different temperatures, hydrostatic pressures and gas concentrations. The mass diffusion theory and the relationships between the processing variables and model input parameters can be used for predicting bubble behaviour during a cure schedule.

To my father and mother. Miss Elk My theory by A. Elk. Brackets Miss, brackets. This theory goes ... more To my father and mother. Miss Elk My theory by A. Elk. Brackets Miss, brackets. This theory goes as follows and begins now. All brontosauruses are thin at one end, much much thicker in the middle and then thin again at the far end. That is my theory, it is mine, and belongs to me and I own it, and what it is too. Presenter That's it, is it? Monty Python's Flying Circus 16-il-72 HOW LoNCý RAVE 'ýO U6E e-N WO R Kl N (4 IN THLS Fjýý c 1) ST

Based on the compressive thermal fragmentation test and model proposed recently, a transcrystalli... more Based on the compressive thermal fragmentation test and model proposed recently, a transcrystalline phase grown adjacent to the surface of a high modulus carbon fibre embedded in polycarbonate was found to lower the thermal stresses in the fibre. The interfacial shear stress, calculated from the compressive stress profile generated by the model, was lowered in the presence of a transcrystalline layer. It is proposed that the transcrystalline layer reduces the radial stresses acting on the fibre, thereby reducing the friction component of the interfacial bond strength.

Compressive thermal stresses in microcomposites-viewed by polarised light microscopyproduce a typ... more Compressive thermal stresses in microcomposites-viewed by polarised light microscopyproduce a typical stress pattern comprising a regular series of fringes along the fibres. Our recent studies have regarded that stress pattern indicative of a continuous fibre fragmentation process and have used it to measure the compressive strength of the fibre and the fibre/matrix interfacial strength. In this study the nature of the compressive fragmentation process is examined by a matrix dissolution procedure proposed recently in the literature. It is found that stress fringes are indeed indicative of fibre breaks but, in addition, they also reflect skin failure by shear deformation and microbuckling and, most importantly, they even reflect reversible microbuckling. Since the reversible microbuckling occurs at a stress level which is just below the compressive strength of the fibre, it is suggested that this marks the onset of its compressive failure.

Magnetoencephalography (MEG) has been used to locate and measure electrical oscillatory activity ... more Magnetoencephalography (MEG) has been used to locate and measure electrical oscillatory activity during working memory (WM) tasks. Frontal midline theta (fmθ) activity was located in all participants and was found to increase in amplitude with increasing task difficulty. In the Sternberg task, fmθ decreased at higher memory loads in agreement with the concept of a capacity-limited physiological response within the WM network. Crossspectral oscillatory activity was investigated using the N-Back task. Increases in amplitude at fmθ and concomitant decreases in amplitude in the gamma frequency ranges (fmγ) were measured at the same frontal midline locations. These findings support the hypothesis that when working memory is engaged, fmθ is associated with the switching off of internally generated neural activity mediated by gamma band oscillations in a network of sites that includes the medial frontal cortex. It is speculated, however, that this activity may not represent gamma oscillations in a specific narrow frequency band but a general shift in amplitude of a broad band response. It was also noted that these frequency-related modulations are similar to the differences observed by between schizophrenia patients and healthy controls in the resting state. The study demonstrates the utility of MEG/beamforming to investigate cognitive processes and supports its potential as a clinical tool.

In this study, we elucidate the changes in neural oscillatory processes that are induced by simpl... more In this study, we elucidate the changes in neural oscillatory processes that are induced by simple working memory tasks. A group of eight subjects took part in modified versions of the N-back and Sternberg working memory paradigms. Magnetoencephalography (MEG) data were recorded, and subsequently processed using beamformer based source imaging methodology. Our study shows statistically significant increases in θ oscillations during both N-back and Sternberg tasks. These oscillations were shown to originate in the medial frontal cortex, and further to scale with memory load. We have also shown that increases in θ oscillations are accompanied by decreases in β and γ band oscillations at the same spatial coordinate. These decreases were most prominent in the 20-40 Hz frequency range, although spectral analysis showed that γ band power decrease extends up to at least 80 Hz. β/γ Power decrease also scales with memory load. Whilst θ increases were predominately observed in the medial frontal cortex, β/γ decreases were associated with other brain areas, including nodes of the default mode network (for the N-back task) and areas associated with language processing (for the Sternberg task). These observations are in agreement with intracranial EEG and fMRI studies. Finally, we have shown an intimate relationship between changes in β/γ band oscillatory power at spatially separate network nodes, implying that activity in these nodes is not reflective of uni-modal task driven changes in spatially separate brain regions, but rather represents correlated network activity. The utility of MEG as a non-invasive means to measure neural oscillatory modulation has been demonstrated and future studies employing this technology have the potential to gain a better understanding of neural oscillatory processes, their relationship to functional and effective connectivity, and their correspondence to BOLD fMRI.

The role of instruction in second language acquisition. Studies in Second Language Acquisition (S... more The role of instruction in second language acquisition. Studies in Second Language Acquisition (Special Issue) 15. Liceras J.M. (1989) On some properties of the "pro-drop" parameter: Looking for missing subjects in non-native Spanish. In S.Gass and J.Schachter (eds.) Linguistic perspectives on second language acquisition, Cambridge:

DiploFoundation, 2022

EXECUTIVE SUMMARY: For a National Society to be well-functioning in its negotiations with decisio... more EXECUTIVE SUMMARY: For a National Society to be well-functioning in its negotiations with decision makers in state government, it needs to have a coherent, unambiguous strategic direction. To encourage the National Society to speak with one voice, this strategy is generally written down in its strategic plan. The plan itself, however, can quickly become an obsolete document unless discussions and negotiations result in commitment to the plan, with all decision-makers in the National Society understanding these commitments. The strategic planning process endeavours to do this. In 2011, Afghanistan’s National Society, the Afghan Red Crescent Society (ARCS), needed to update its strategic plan in line with the IFRC Strategy 2020 (IFRC, 2010). In essence, Strategic Plan 2012-2015 (ARCS, 2011) was the written expression of the strategic planning process that was carried out during August and September 2011 - a process in which ARCS made decisions on where it wanted to be and why, and how it was going to get there. The specific reasons for developing such a plan, however, were not immediately apparent to the majority of staff (apart from that it was mandatory to have one), even those at senior level. Identifying the reasons for planning and how to approach the process therefore played a significant role in developing the final document. As strategic plans are generally functional documents which provide little information on the process that formed them (thus limiting the applicability of textual discourse analysis), this paper focuses on the strategic planning process. Furthermore, as strategic planning often involves a series of high-level closed meetings held primarily to update the previous plan, this paper is unusual as it also illustrates the diplomacy required to build a policy environment for a plan that also included organisational restructuring. Essentially, this paper attempts to show how humanitarian diplomacy can, and often needs to be applied to Red Cross Red Crescent (RCRC) National Societies during strategic planning in order to affect positive changes. The role of facilitator as a humanitarian diplomat is discussed and it is considered how modifying the mode of discourse in an organisation can affect the power relations to encourage a more inclusive approach to developing strategies. A situational analysis prior to the process, and a survey at the start of the process are both shown to inform how the strategic planning sessions were conducted. Quiet diplomacy and a series of open communicative tasks based on social constructivist theory was applied to support the creation of a shared reference framework that encouraged cooperation, rather than competition, between members of the strategic planning committee. Some of the techniques used in sessions, which are commonly used in classroom teaching, are presented. An evidence-based logos approach to organisational restructuring , which was used to develop strategic goals on which the mission and vision of ARCS is now based, is evaluated, highlighting the need to use a variety of tools from the humanitarian toolbox when dealing with complex decision-making processes.

A three-stage project to eliminate violence in ten schools in Jalalabad, Afghanistan has been suc... more A three-stage project to eliminate violence in ten schools in Jalalabad, Afghanistan has been successfully completed, resulting in the near elimination of violence in these schools. The first stage, a baseline study, identified the main categories of violence as 1) physical violence and humiliating treatment of children by teachers (often considered as an acceptable form of punishment); 2) high levels of sexual abuse particularly against boys by male teachers; and 3) violence by children against children. The second stage, an intervention, involved training teachers and administrators in order to raise their awareness of the issues revealed in the baseline study, and to provide alternatives to violence as a form of punishment. Parents, leaders and clergy (Mullahs) within the community were also encouraged to undertake more positive roles in the education of their children through the set up of Parent-Teacher-Student Associations (PTSAs). Community-based Child Protection Committees (CPCs), comprising members of the schools, communities and provincial education authorities were established as a means of dealing with reports of abuse and as a conduit to the national Child Protection Action Network (CPAN). The children themselves were trained to recognise their rights and to speak out through School Student Councils (SSCs) to provide them with a voice within the school. The third stage, which assessed the effectiveness of the interventions through a cross-sectional analysis with other schools in the same communities, highlighted that 1) teachers were not only more aware of the inappropriateness of using of physical and humiliating punishment (PHP) toward children but were also using alternatives to violence as a form of punishment, 2) procedures for dialogue between teachers/schools authorities and students were put in place, and 3) parents and community elders paid closer attention to the educational needs of the children in the community. It was also noted that student dropout rates decreased in all schools that underwent the intervention, in some cases by over 50%. These findings provide strong support for the establishment of a nation-wide directive based on the strategies employed in this project to enable children to learn in fear-free environments.

Word Count: 4997 (excluding executive summary and references)

Reflections on the Westward Expansion of the Phoenicians in the Early Iron Age The Search for Silver and Technology Transfer, 2024

Cities on the Levantine coast in the area known as Phoenicia suffered none of the destruction exp... more Cities on the Levantine coast in the area known as Phoenicia suffered none of the destruction experienced to the north or south at the end of the Late Bronze Age. Having emerged unscathed from this period of upheaval, the distributed, city state, power structure of the region was well suited towards facilitating continuity in long distance maritime ventures to acquire metals unavailable locally in exchange for timber, wine and other locally sourced products. This paper integrates the conclusions of a recent reanalysis of compositional and lead isotope legacy data from early silver hoards in the Southern Levant by Jonathan Wood, alongside other archaeological evidence of trade. In addition to receiving silver from Anatolia, at least by the second half of the 10th Century BCE, we believe that Tel Dor in Phoenicia was an important receiver of silver smelted from jarosite ores from both Cyprus and Iberia. We further suggest that the technology to mine and smelt jarositic ores in Iberia, as well as the ability to cupellate silver from argentiferous lead, may have arrived from Cyprus on Phoenician maritime expeditions.

Journal of Eastern Mediterranean Archaeology and Heritage Studies, 2020

A recent reanalysis of compositional and lead isotope legacy data from the early silver hoards of... more A recent reanalysis of compositional and lead isotope legacy data from the early silver hoards of the southern Levant (ca. twelfth–ninth centuries BCE) identified that not only was most of this hacksilver mixed but that it probably derived from the Pyritic belt of southern Iberia, the Taurus mountains in Anatolia, and a third unknown source. We propose that the unknown component of Tel Dor’s hacksilver was silver potentially derived from ores mined at Kalavasos on Cyprus. The presence of Cypriot silver in the southern Levant complements finds of Phoenician pottery on Cyprus, supporting that there was continuity of trade from the end of the Bronze Age to the beginning of the Iron Age between Cyprus and the Levant. Furthermore, our findings suggest that the technology required to smelt and cupellate argentiferous jarosite ores was first practiced on Cyprus prior to risky and costly ventures to Iberia. keywords: Tel Dor, silver, jarosite, Phoenicians, mixing lines, lead isotopes

Internet Archaeology, Sep 30, 2023

Wood, J.R., Ponting, M. and Butcher, K. 2023 'Response to comment of Albarède and colleag... more Wood, J.R., Ponting, M. and Butcher, K. 2023 'Response to comment of Albarède and colleagues', Internet Archaeology 61. https://doi.org/10.11141/ia.61.10.response

Internet Archaeology, Aug 31, 2023

Matthew Ponting drilling into a Roman coin Although silver coins have been investigated through t... more Matthew Ponting drilling into a Roman coin Although silver coins have been investigated through the lens of geological provenance to locate argentiferous ore deposits exploited in their production, we consider that this avenue of research may be a cul-de-sac, especially for studies that rely heavily on deciphering lead and silver isotope signatures that may have been altered by the addition of lead and copper (and their associated impurities) during silver refining and debasement, and by ancient recycling of coinage. Instead, we focus our attention on mints, by analysing the compositions of over 1000 silver coins from the early 1st century BC to AD 100. We propose that lead from the west Mediterranean was used exclusively to refine silver at mints in the West, and that an unknown lead supply (possibly from Macedonia), used in the East by the Late Seleucid ruler Philip I Philadelphus and later Mark Antony, was mixed with western lead. Extensive mixing of lead and/or silver coins is particularly evident under Nero and Vespasian, aligning with historically attested periods of recycling following currency reform. We further propose that coins minted in the kingdom of Mauretania used different lead and silver sources from the majority of coins minted in the western Mediterranean, and that silver coins minted at Tyre are derived from silver refined in the west Mediterranean. Coinage minted at Alexandria is consistent with debasement of recycled Roman denarii, thereby suggesting that denarii were deliberately removed from circulation to mint tetradrachms during the early Imperial Roman period.

Advanced Composites Letters, Jul 1, 1994

A model has been proposed that represents the compressive fragmentation phenomenon and can evalua... more A model has been proposed that represents the compressive fragmentation phenomenon and can evaluate the interfacial shear strength without recourse to complicated stress transfer models. The temperature dependence of the interfacial shear strength is investigated for carbon fibre-polycarbonate microcomposites and the values obtained are applicable to a system that has weak interfacial bonding.

Advanced Composites Letters, Sep 1, 1993

Archaeological and Anthropological Sciences, Jul 16, 2021

Doctoral thesis, UCL (University College London)., Mar 28, 2019

The hypothesis that Phoenician expansion across the Mediterranean resulted in the movement of tec... more The hypothesis that Phoenician expansion across the Mediterranean resulted in the movement of technological ideas from East to West and materials from West to East is explored through investigating ancient silver and silver extraction technologies. An approach which combines both compositional and lead isotope data is applied to identify recycled silver from the Early and Late Iron Age hoards of the southern Levant. Signatures indicate that components of this mixed silver derived from Anatolia, Iberia and Cyprus in Early Iron Age, and Greece and Iberia in the Late Iron Age. Iberian signatures from the Early Iron Age hoards are consistent with native silver and silver extracted from jarosite ores. With these hoards dating from the 11 th century BC, this situates the Phoenicians in Iberia much earlier than is usually attested and suggests that smelting and cupellation technologies travelled with them. A silver ingot recovered from La Rebanadilla in southeast Iberia, exhibiting a similar signature to the hoard silver, may indicate that silver was transported in a semi-refined form.

Archaeometry

Archaeological and Anthropological Sciences

Journal of World Prehistory, Jan 22, 2019

The origins of the silver trade across the Mediterranean, and the role of the Phoenicians in this... more The origins of the silver trade across the Mediterranean, and the role of the Phoenicians in this phenomenon, remain contentious. This is partly because of difficulties encountered when trying to assign archaeological silver to its geological sources. Here we present a reanalysis of Iron Age silver hoards in the southern Levant, which demonstrates not only that recycling of silver was widespread in the Early and Late Iron Age, but that the components of this mixed silver originated from the Aegean, Anatolia and the western Mediterranean. An assessment of lead isotope analyses combined with compositional data allows the identification of mixing lines based on gold levels in the silver and the Pb crustal age (or, more loosely, geological age) of the ore from which the silver originated. It is shown that, from as early as the 11th century BC, these mixed silver signatures derive from the Taurus mountains in Anatolia, from Iberia and an unknown source-with Sardinia as an additional possibility-and Laurion in Greece in the Late Iron Age. In contrast to copper, which was deliberately alloyed with silver, gold appears to have been mixed unintentionally, through the melting down of silver objects with gold parts. It is suggested that vertical mixing lines (with constant Pb crustal age but variable Au), may indicate the melting down and mixing of silver in times of unrest, both here and in other contexts. Gold and lead concentrations in the silver indicate that native silver from Iberia was most likely used in the Early Iron Age, suggesting that the first people to convey silver to the southern Levant were not miners but traders who had acquired silver directly from the indigenous Bronze Age inhabitants of Iberia. However, evidence of the exploitation of jarosite also supports that silver ore mining and cupellation was ongoing in Iberia at a similar time, and continued in the Late Iron Agepotentially a result of technological transfer from the East. In essence, the western Mediterranean origin of the silver in these Early Iron Age southern Levantine hoards supports an emerging picture of Mediterranean interactions and trade relations in the increasingly bright Dark Ages (c. 1200-800 BC).

Journal of Archaeological Method and Theory

Iraq, 2020

Archaeological and Anthropological Sciences, 2021

Archaeometry, 2022

A fragment of a silver ingot recovered from the Phoenician settlement of La Rebanadilla, near Mal... more A fragment of a silver ingot recovered from the Phoenician settlement of La Rebanadilla, near Malaga, in south-east Iberia has been investigated using lead isotope and compositional analyses. The ingot, which was found at the lowest levels of the site, potentially dates from 11th-9th century BC, placing it alongside the hoards of hacksilver found in the southern Levant in terms of chronology. The Pb crustal age (from lead isotope data) and compositional data support that the ingot derives from Hercynian-age ores with high bismuth concentrations. This signature is consistent with the Pyritic belt of south-west Iberia, particularly around the ancient mining areas of Riotinto. It is proposed that the silver for this ingot was extracted from jarosite ores at Riotinto, where it was coarsely refined through cupellation into an ingot still retaining high levels of lead, before being transported to La Rebanadilla, which was a potential point of departure back to the Phoenician homeland. The...

Journal of Eastern Mediterranean Archaeology & Heritage Studies, 2020

A recent reanalysis of compositional and lead isotope legacy data from the early silver hoards of... more A recent reanalysis of compositional and lead isotope legacy data from the early silver hoards of the southern Levant (ca. twelfth–ninth centuries BCE) identified that not only was most of this hacksilver mixed but that it probably derived from the Pyritic belt of southern Iberia, the Taurus mountains in Anatolia, and a third unknown source. We propose that the unknown component of Tel Dor's hacksilver was silver potentially derived from ores mined at Kalavasos on Cyprus. The presence of Cypriot silver in the southern Levant complements finds of Phoenician pottery on Cyprus, supporting that there was continuity of trade from the end of the Bronze Age to the beginning of the Iron Age between Cyprus and the Levant. Furthermore, our findings suggest that the technology required to smelt and cupellate argentiferous jarosite ores was first practiced on Cyprus prior to risky and costly ventures to Iberia.

Journal of World Prehistory, 2019

Responses to the 12th Century BC Collapse: Recovery and Restructuration in the Early Iron Age Near East and Mediterranean

Economic circularity is the ability of a society to reduce waste by recycling, reusing, and repai... more Economic circularity is the ability of a society to reduce waste by recycling, reusing, and repairing raw materials and finished products. This concept has gained momentum in academia, in part due to contemporary environmental concerns. Although the blurry conceptual boundaries of this term are open to a wide array of interpretations, the scholarly community generally perceives circular economy as a convenient umbrella definition that encompasses a vast array of regenerative and preservative processes.

Despite the recent surge of interest, economic circularity has not been fully addressed as a macrophenomenon by historical and archaeological studies. The limitations of data and the relatively new formulation of targeted research questions mean that several processes and agents involved in ancient circular economies are still invisible to the eye of modern scholarship. Examples include forms of curation, maintenance, and repair, which must have had an influence on the economic systems of premodern societies but are rarely accounted for. Moreover, the people behind these processes, such as collectors and scavengers, are rarely investigated and poorly understood. Even better-studied mechanisms, like reuse and recycling, are not explored to their full potential within the broader picture of ancient urban economies.

This volume stems from a conference held at Moesgaard Museum supported by the Carlsberg Foundation and the Centre for Urban Networks Evolutions (UrbNet) at Aarhus University. To enhance our understanding of circular economic processes, the contributions in this volume expand the framework of the discussion by exploring circular economy over the longue durée and by integrating an interdisciplinary perspective. Furthermore, the volume gives prominence to classes of material, processes, agents, and methodologies generally overlooked or ignored in modern scholarship.