Joanne Dyer

British Museum · Scientific Research

Visualizing the internal structure of museum objects is a crucial step in acquiring knowledge about the origin, state, and composition of cultural heritage artifacts. Among the most powerful techniques for exposing the interior of museum objects is computed tomography (CT), a technique that computationally forms a 3D image using hundreds of radiogr...

The materials of six Karen textiles from the British Museum’s collection were investigated with the main aim of studying the production changes over the course of the nineteenth century and how these changes related to local and colonial trade networks. The textiles span chronologically from the 1830s to the early 1900s according to their attributi...

In 1982, eight people—archaeologists, colour scientists and analysts—met in a room in King’s Manor, York University, to discuss a subject of significance to them all: the analysis of dyes on archaeological and historical textiles [...]

Scientific analyses of the traditional materials and methods in thangka production are uncommon, as thangkas are sacred objects, the sampling of which is discouraged, in order to preserve their integrity. This study builds on this important ethical challenge and presents a three-stage methodology that systematically delves deeper into each layer of...

Mount components and textile borders represent important elements of Asian paintings. However, they are often side-lined or not considered an integral part of the original piece, as they may be later additions or may have been replaced during historic conservation or mounting interventions. Nevertheless, evidence is sometimes present that textile b...

Commonly exhibited in museum galleries, animal mummies have been the focus of interest of both visitors and researchers alike. The study of these animal remains not only provides new insights into embalming techniques, but also brings a unique perspective on religious, social and economic practices. Twenty animal mummies are discussed in this study...

This paper presents the results of the work of the new field initiative launched by the British Museum at the Darband-i Rania pass in the Kurdistan Region of Iraq. The pass is located at the northeastern corner of Lake Dokan, where, though now subsumed into the lake, the Lower Zab flows from the Peshdar into the Rania Plain. It is a strategic locat...

When the imagination conjures up an image of an Egyptian mummy, it is normally one of a human body wrapped with undyed linen bandages. However, the reality was much more colourful, as shown by the set of red mummy shrouds and textile fragments from Pharaonic Egypt considered in this work. The textiles were subjected to scientific investigation with...

“Lac” is a term referring to a pink-red-purple organic colourant derived from an insect and used as a lake pigment or a dye. Although historical sources indicate extensive usage, findings in historical samples remain scarce and are based on the detection of laccaic acids A and B, which are the main colourant molecules in lac. In this work various l...

Abstract Ukiyo-e Japanese woodblock prints were mass-produced in the Edo Period and early impressions of a given print are generally of higher quality and more sought after by connoisseurs than late impressions. The present publication presents an innovative approach that combines the classical method of examining line quality with a systematic stu...

Although medieval alabaster sculptures might appear white at present, they were colourful once, because painting and gilding the stone was an integral part of their production. This work presents the study of polychrome remnants on a selection of fourteenth century English alabasters, using multiple scientific methods (microscopy, spectroscopic and...

The archaeological complex of Dunhuang (northwestern Gansu, China) is considered a pearl on the Silk Road and the content of its caves revolutionised oriental studies. The British Museum hosts a significant number of textiles and textile fragments from the site. Although mostly catalogued and studied from the point of view of textile production, we...

This work explores the use of multispectral imaging (MSI) techniques applied to the investigation of Late Antique (c. 250±800 AD) textiles found in Egypt. Although the use of these techniques is well-established in the study of polychrome surfaces, they have only been sparingly and often unsystematically applied to the investigation of textiles. Th...

Infrared-reflected (IRR) image of textile fragment A. (TIF)

Infrared-reflected (IRR) image of textile fragment C. (TIF)

Ultraviolet-reflected (UVR) image of textile fragment A. (TIF)

Infrared-reflected (IRR) image of textile fragment B. (TIF)

Ultraviolet-reflected (UVR) image of textile fragment B. (TIF)

Ultraviolet-reflected (UVR) image of textile fragment C. (TIF)

The composition of the ancient wax-based painting technique known as encaustic has long been the subject of debate. Ancient sources provide few details of the technology, and modern understanding of the medium is restricted to theoretical interpretation and experimental observation. In this multi-analytical collaborative study, a number of analytic...

A strategy based on electrospray ionisation (ESI) in negative mode coupled with quadrupole-time of flight (Q-ToF) detection techniques was adopted to characterise some samples of shellac resin. Flow injection analysis (FIA) was used to investigate the distribution of the components of the resin. Eight groups of compounds with increasing masses were...

An important example of a mixture of red colourants from plant and insect sources has been found during a recent investigation of a purple pigment on a 3rd century BC oinochoe from Canosa di Puglia present in the British Museum collection. Further investigation was carried out to elucidate both the nature of this pigment and its possible method of...

Photo-induced luminescence imaging techniques, such as UV-induced visible luminescence (UVL) and the more recently developed technique of visible-induced infrared luminescence (VIL), have been invaluable for the study of ancient polychromy, allowing the detection and mapping of luminescent materials, such as varnishes, consolidants, organic binders...

This contribution presents recent work on a Roman period limestone sculpture depicting the ancient Egyptian god Horus (British Museum EA 51100). In ancient Egypt, the god Horus was the divine representation of the living king and was commonly represented as a man with the head of a falcon. The iconography and style of depictions of Horus and other...

A number of Roman period Egyptian funerary portraits are curated by the Department of Ancient Egypt and Sudan at the British Museum (BM). A collaborative research project to investigate this collection was undertaken jointly by the BM and the National Gallery, London, the owner of two of the portraits. In the course of this examination four portrai...

This paper revisits the 1991–1995 British Museum field trial on anoxic storage, where 23 registered ethnographic rubber objects were enclosed in oxygen barrier film Cryovac BDF-200 with sachets of the oxygen absorbent Ageless Z. A unique opportunity for study was presented since most of the enclosures have remained sealed since 1995. Techniques suc...

The transient species formed following excitation of fac-[Re(CO)3(F2dppz)(py)]+ (F2dppz = 11,12-difluorodipyrido[3,2-a:2′,3′-c]phenazine) bound to double-stranded polynucleotides[poly(dA-dT)]2 or [poly(dG-dC)]2 have been studied by transient visible and infra-red spectroscopy in both the picosecond and nanosecond time domains. The latter technique...

During the conservation of a late fourteenth-century ‘kettle-hat’ helmet in preparation for its loan to the Royal Armouries Museum, traces of red surface decoration were discovered. is previously unrecorded feature initiated the most in-depth examination of the helmet since its acquisition by the British Museum in 1856. The red material was identi...

A phenanthridine derivative covalently linked to a ruthenium complex yields an imaging probe whose fluorescence intensity and lifetime change substantially in the presence of RNA.

Over the past two decades, the photolytic reactions of dibenzyl ketones sorbed on zeolites have been investigated. The reported results are consistent with a supramolecular model that takes into account the physical and chemical nature of the structure of the zeolites and their effect on the reactive radical intermediates produced by photolysis of...

The location of ring-substituted ketones, such as 2-phenylcycloalkanones in surfactant solutions, is readily characterized by FT-IR spectroscopy, since the sensitivity of the carbonyl group stretching vibration to changes in hydrogen bonding makes this an effective reporter for hydrophobic micellar core environments versus hydrophilic aqueous envir...

Transient species formed by photoexcitation (400 nm) of [Ru(dppz)(tap)2]2+ (1) (dppz = dipyrido[3,2-a:2',3'-c]phenazine; tap=1,4,5,8-tetraazaphenanthrene) in aqueous solution and when intercalated into a double-stranded synthetic polynucleotide, [poly(dG-dC)]2, have been observed on a picosecond timescale by both visible transient absorption (allow...

The process of modeling the fluorescence resonance energy transfer (FRET) process for a donor-acceptor pair can be rather challenging, yet few computer programs exist that allow such modeling to be done with relative ease. In order to address this, we have developed a Java-based program, FRETView, which allows numerous FRET parameters to be obtaine...

The photophysical properties of [Re(CO)(3)(dppz)(py)](+) (dppz = dipyrido-[3,2-a:2',3'-c] phenazine) and its 11,12 substituted derivatives [Re(CO)(3)(dppzMe(2))(py)](+) and [Re(CO)(3)(dppzF(2))(py)](+) have been examined in organic and aqueous environments using phosphorescence and picosecond transient visible and infrared absorption spectroscopic...

We describe the design of new fluorescent binary probe sensors for DNA detection based on spin-forbidden resonance energy transfer (SF-RET). Binary probes consist of a donor and acceptor fluorophores that are attached to two different oligonucleotides and serve as a resonance energy transfer (RET) donor-acceptor pair when hybridized to adjacent sit...

Photoisomerization of encapsulated Z-enecarbamates within the hydrophobic chiral cavities of gamma-CD showed higher diastereoselectivities in the photoproducts than those obtained in solution. The selective encapsulation of the enecarbamates and the following isomerization process are both diastereoselectively controlled by gamma-CD.

[reaction: see text] A luminogenic probe for peptide dephosphorylation has been developed. It consists of a serine-/tyrosine-containing peptide modified on the N-terminus with a tryptophan residue and a DTPA chelate capable of binding Tb(3+). We propose a mechanistic model for the luminescence enhancement based on the interconversion of monomeric a...

[reaction: see text] Two-photon induced Wolff rearrangement of a terphenyl diazoketone 1 was achieved by using focused laser pulses of 532 nm from a Q-switched Nd:YAG laser. The nonfluorescent terphenyl diazoketone 1 was transformed into a fluorescent ester derivative 4, which can be detected in situ using the focused laser pulses at 532 nm. Laser...

In this paper we demonstrate the use of picosecond time-resolved infrared spectroscopy (ps-TRIR) to monitor the early structural dynamics of DNA bases and polydeoxynucleotides following UV excitation in solution.

Time-resolved infrared (TRIR) spectroscopy, a combination of UV flash photolysis and fast infrared detection, is a powerful technique for probing excited states and detecting reaction intermediates. In this Perspective we highlight the application of TRIR to excited states by probing the nature of the lowest excited states of fac-[Re(CO) (3)(dppz-C...

The photophysical properties of fac-[Re(CO)3(dppz)(py)]+ (1, where dppz = dipyrido[3,2-a: 2',3'-c]phenazine) in CH3CN have been investigated using a series of complementary techniques including visible and infrared transient absorption and resonance Raman spectroscopy on the picosecond and nanosecond timescales. The results confirm previous reports...

We have constructed a broadband ultrafast time-resolved infrared (TRIR) spectrometer and incorporated it into our existing time-resolved spectroscopy apparatus, thus creating a single instrument capable of performing the complementary techniques of femto-/picosecond time-resolved resonance Raman (TR3), fluorescence, and UV/visible/infrared transien...

We report on ultrafast pump and probe studies of biological systems, in the form of polynucleotide and calf thymus DNA complexes. Molecules for study are bound to the polynucleotides and probed in the visible region to observe changes in the absorption over time. Various dipyridophenazine metal complexes are studied alone and complexed with DNA or...

The photophysics of fac-[(dppz-12-NO2)Re(CO)3(4-Me2Npy)]+ in CH3CN have been investigated using picosecond time-resolved IR (ps-TRIR) spectroscopy, to reveal the first example of a Re(I)–dppz complex with a charge separated lowest-lying excited state.

The photophysics of fac-[(dppz-12-NO2)Re(CO)3(4-Me2Npy)]+ in CH3CN have been investigated using picosecond time-resolved IR (ps-TRIR) spectroscopy, to reveal the first example of a Re(I)-dppz complex with a charge separated lowest-lying excited state.

A series of M(η5-C5R5)(CO)2(C5H10) complexes (R = H, Me or Ph; M = Mn or Re) have been characterised at low (Re only) and room temperature (R = H only) using infrared spectroscopy. The decay rates of these complexes have been measured and compared to those of the corresponding n-heptane analogues. These comparisons show that the organometallic cycl...