29 research outputs found
Copper for the Pharaoh: Identifying multiple metal sources for Ramesses' workshops from bronze and crucible remains
The origin of copper used in Late Bronze Age (LBA) Egypt is very poorly understood despite its cultural and economic importance attested in archaeological and historical sources. Extensive literature discusses major LBA copper sources such as Cyprus (oxhide ingots), Oman (bun ingots) and Egyptian-controlled sites in the Sinai. This paper presents new chemical and lead isotope data for Egyptian copper alloys excavated in several bronze production workshops from the New Kingdom capital Pi-Ramesse, expanding on earlier data from Amarna. Supporting data is obtained from the analysis of crucible remains from the same context, for which the potential contribution of lead isotope analysis is critically evaluated. Diachronic changes in the provisioning of these Egyptian workshops are discussed, incorporating an extensive overview of currently known Egyptian mining and metallurgy. The results have major implications for our understanding of LBA copper circulation in the wider region, for the first time analysing a major Egyptian ‘consumer’ assemblage. The analytical results reveal a complex picture of variable copper supply to the Ramesside workshops, which involved both the recycling of existing bronzes and the use of freshly smelted copper from various origins to produce fresh alloys. Importantly, this includes crucial new evidence for the melting of (Cypriot) oxhide ingot fragments in crucibles for alloying. The royal, internationally connected nature of these workshops makes Pi-Ramesse an exceptional case study of LBA metal trade, and hypotheses raised in this paper highlight the need for more extensive analysis of ancient Egyptian copper artefacts to grasp metal circulation throughout Egypt's long history. More refined frameworks, incorporating the variety of private as well as royal contexts, will improve understanding of Egypt's ancient economic organisation. This paper offers new perspectives onto LBA metal supply and consumption networks, with broader archaeological interpretative models of economic and political interactions across the wider ancient Near East
Bronze metallurgy in the Late Phrygian settlement of Gordion, Turkey
A detailed understanding of bronze production remains absent in most archaeological contexts, despite the fundamental importance of this alloy. Here, we present a comprehensive discussion of the bronze production remains from Late Phrygian/Achaemenid Gordion: crucibles, moulds and casting waste and their find contexts. A detailed microscopic analysis of crucibles is complemented by chemical characterisation of their main materials (ceramic and slag) in order to discuss the technical performance of the crucibles and to evaluate the materials used for the metallurgical process. Given the lack of contemporary parallels, repeated reference is made to the Egyptian crucibles from Pi-Ramesse, for which similarly detailed descriptions are available. The crucible analyses are then connected to the other production remains to obtain a more holistic understanding of the metallurgical process. Finally, these technical observations are interpreted in their particular archaeological context at Gordion and discussed from a wider perspective. The results presented here offer the first detailed overview of bronze production for ancient Phrygia, as well as the wider region. Through the inclusion of extensive online supplementary data, this paper offers a detailed technical overview of ancient (bronze) crucible analysis, of which very few examples are currently available in the wider literature
Animal Models of Dyssynchrony
Cardiac resynchronization therapy (CRT) is an important therapy for patients with heart failure and conduction pathology, but the benefits are heterogeneous between patients and approximately a third of patients do not show signs of clinical or echocardiographic response. This calls for a better understanding of the underlying conduction disease and resynchronization. In this review, we discuss to what extent established and novel animal models can help to better understand the pathophysiology of dyssynchrony and the benefits of CRT
Echocardiographic prediction of outcome after cardiac resynchronization therapy: conventional methods and recent developments
Echocardiography plays an important role in patient assessment before cardiac resynchronization therapy (CRT) and can monitor many of its mechanical effects in heart failure patients. Encouraged by the highly variable individual response observed in the major CRT trials, echocardiography-based measurements of mechanical dyssynchrony have been extensively investigated with the aim of improving response prediction and CRT delivery. Despite recent setbacks, these techniques have continued to develop in order to overcome some of their initial flaws and limitations. This review discusses the concepts and rationale of the available echocardiographic techniques, highlighting newer quantification methods and discussing some of the unsolved issues that need to be addressed
Cardiac resynchronization therapy guided by cardiovascular magnetic resonance
Cardiac resynchronization therapy (CRT) is an established treatment for patients with symptomatic heart failure, severely impaired left ventricular (LV) systolic dysfunction and a wide (> 120 ms) complex. As with any other treatment, the response to CRT is variable. The degree of pre-implant mechanical dyssynchrony, scar burden and scar localization to the vicinity of the LV pacing stimulus are known to influence response and outcome. In addition to its recognized role in the assessment of LV structure and function as well as myocardial scar, cardiovascular magnetic resonance (CMR) can be used to quantify global and regional LV dyssynchrony. This review focuses on the role of CMR in the assessment of patients undergoing CRT, with emphasis on risk stratification and LV lead deployment
Myocardial tagging by Cardiovascular Magnetic Resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications
Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging
Sasanian copper and billon coins from the collections of the Royal Museums of Art and History, Brussels, Belgium-insights using semi-quantitative analysis by mu XRF
status: publishe
