Late Byzantine Mineral Soda High Alumina Glasses from Asia Minor: A New Primary Glass Production Group

The chemical characterisation of archaeological glass allows the discrimination between different glass groups and the identification of raw materials and technological traditions of their production. Several lines of evidence point towards the large-scale production of first millennium CE glass in a limited number of glass making factories from a mixture of Egyptian mineral soda and a locally available silica source. Fundamental changes in the manufacturing processes occurred from the eight/ninth century CE onwards, when Egyptian mineral soda was gradually replaced by soda-rich plant ash in Egypt as well as the Islamic Middle East. In order to elucidate the supply and consumption of glass during this transitional period, 31 glass samples from the assemblage found at Pergamon (Turkey) that date to the fourth to fourteenth centuries CE were analysed by electron microprobe analysis (EPMA) and by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The statistical evaluation of the data revealed that the Byzantine glasses from Pergamon represent at least three different glass production technologies, one of which had not previously been recognised in the glass making traditions of the Mediterranean. While the chemical characteristics of the late antique and early medieval fragments confirm the current model of glass production and distribution at the time, the elemental make-up of the majority of the eighth- to fourteenth-century glasses from Pergamon indicate the existence of a late Byzantine glass type that is characterised by high alumina levels. Judging from the trace element patterns and elevated boron and lithium concentrations, these glasses were produced with a mineral soda different to the Egyptian natron from the Wadi Natrun, suggesting a possible regional Byzantine primary glass production in Asia Minor

Analysis and simulation of nonlinear handling characteristics of automotive vehicles with focus on lateral load transfer

This paper mainly investigates steady-state nonlinear cornering behaviour of vehicles under lateral load transfer. A normal load dependent nonlinear cornering stiffness is utilised instead of the constant one to reflect the effect of normal load fluctuations. Thus, the relationship between the nonlinear cornering stiffness, tyre property coefficients, roll stiffness ratio and lateral load transfer has been formulated. A clear and simple criterion has been proposed to demonstrate how the handling behaviour is changed in the high lateral acceleration region. This criterion indicates that the nonlinear handling behaviour is dependent on the car's roll stiffness ratio, static margin, tyre cornering stiffness and tyre property, coefficients. It may be considered as one of many advantageous criteria in motor vehicle design

The Yığma Tepe of Pergamon: Internal construction of a monumental burial mound from shear wave reflection sounding and wavefield modelling

The Yığma Tepe of Pergamon is one of the largest known burial mounds in the Eastern Mediterranean. Its internal structure, especially the existence and location of burials, remains unknown so far because its height of 32 m and the diameter of 158 m have restricted extensive excavations. To explore the interior of the Yığma Tepe, we applied shear wave reflection profiling and traveltime tomography, locally complemented by electrical resistivity tomography. Shear wave reflection imaging enabled us to identify the layering and localize structures down to the basal surface of the mound with a metre‐scale resolution. A grid of crossing SH‐wave profiles with 4‐m line spacing covered the central mound area. The Yığma Tepe can be subdivided into three stratigraphic layers representing different construction phases, each about 10 m thick. The deepest is a consolidated layer with a locally compacted surface. SH‐wave reflection imaging verified the collapsed remains of a tunnel system and a shaft at about 30‐m depth that had been dug into the mound at the level of the basal surface at the beginning of the 20th century. The tunnel collapse created a damage zone of decreased S‐wave velocity reaching up to the overlying middle layer, in which four seismic objects of interest (SOIs) were detected. The largest of these SOIs is a north–south‐oriented structure, about 15 m long and 4 m wide. SH‐viscoelastic forward modelling showed that it likely consists of a collapsed walled cavity with a zone of loosened soil above. The third layer covers the underlying two and is enriched with large stone packages as verified by local excavations. We show the capabilities of shear‐wave reflection seismic to image small‐scale structures under complicated topographic conditions and how characteristics of cavities and volumes of decompacted soil can be evaluated by wavefield modelling.Agence nationale de la recherche (ANR) http://dx.doi.org/10.13039/501100001665Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659German Archaeological Institut (DAI