Koan amphorae from Halasarna – investigations in a Hellenistic amphora production centre

Ceramic amphorae have been the most popular transport and storage containers for a large variety of liquid and solid products. The amphorae of the present study were used as transport containers for wine from the island of Kos (East Aegean). Therefore, they had to fulfil certain requirements in terms of mechanical strength and toughness but also in terms of standardization of vessel size and shape. An assemblage of amphora fragments from the excavation of ancient Halasarna, an amphora production centre, will be presented. The ceramics were studied by means of their chemical and mineralogical composition and fabric. Furthermore, their material properties were measured and their mechanical performance was simulated in computer models.     

Effect of mollusc eating on human bone strontium levels

Empirical aspects of the movement of strontium through the food chain suggest that the level of bone strontium can be used as an indicator of the percentage of meat in human diet. In general, skeletal remains from agricultural peoples are expected to have high bone strontium levels relative to hunter-gatherers from the same geographical region because plants contain relatively higher amounts of strontium when compared with animal products. The results of the study described in this paper, however, indicate that the inclusion of molluscs as a component of the diet may produce the opposite of the expected strontium values. Burials from an Archaic (c. 2500 BC) hunting-gathering population excavated from Lu^o25, an archaeological site in northern Alabama, USA, exhibit a mean bone strontium level ( atomic absorption; neutron activation) that is higher than the mean level from an agricultural Mississippian (c. AD 1400) population ( atomic absorption; neutron activation) that was buried at the same site. The samples were analysed by two techniques (atomic absorption spectrometry and neutron activation analysis) and the results compared favourably; therefore, the results can be accepted as valid rather than being due to technique error. We propose that the ingestion of molluscs, whose meat is known to contain large amounts of strontium, has produced this reversal from expected results.     

Cultural dynamics and ceramic resource use at Late Bronze Age/Early Iron Age Troy,northwestern Turkey

Changes in resource use over time can provide insight into technological choice and the extent of long-term stability in cultural practices. In this paper we re-evaluate the evidence for a marked demographic shift at the inception of the Early Iron Age at Troy by applying a robust macroscale analysis of changing ceramic resource use over the Late Bronze and Iron Age. We use a combination of new and legacy analytical datasets (NAA and XRF), from excavated ceramics, to evaluate the potential compositional range of local resources (based on comparisons with sediments from within a 10 km site radius). Results show a clear distinction between sediment-defined local and non-local ceramic compositional groups. Two discrete local ceramic resources have been previously identified and we confirm a third local resource for a major class of EIA handmade wares and cooking pots. This third source appears to derive from a residual resource on the Troy peninsula (rather than adjacent alluvial valleys). The presence of a group of large and heavy pithoi among the non-local groups raises questions about their regional or maritime origin.     

Equivalent Damping in Support of Direct Displacement-Based Design

The concept of equivalent linearization of nonlinear system response as applied to direct displacement-based design is evaluated. Until now, Jacobsen's equivalent damping approach combined with the secant stiffness method has been adopted for the linearization process in direct displacement-based design. Four types of hysteretic models and a catalog of 100 ground motion records were considered. The evaluation process revealed significant errors in approximating maximum inelastic displacements due to overestimation of the equivalent damping values in the intermediate to long period range. Conversely, underestimation of the equivalent damping led to overestimation of displacements in the short period range, in particular for effective periods less than 0.4 seconds. The scatter in the results ranged between 20% and 40% as a function of ductility. New equivalent damping relations for four structural systems, based upon nonlinear system ductility and maximum displacement, are proposed. The accuracy of the new equivalent damping relations is assessed, yielding a significant reduction of the error in predicting inelastic displacements. Minimal improvement in the scatter of the results was achieved, however. While many significant studies have been conducted on equivalent damping over the last 40 years, this study has the following specific aims: (1) identify the scatter associated with Jacobsen's equivalent damping combined with the secant stiffness as utilized in Direct Displacement-Based Design; and (2) improve the accuracy of the Direct Displacement-Based Design approach by providing alternative equivalent damping expressions.     

Real-time Seismic Damage Detection of Concrete Shear Walls Using Artificial Neural Networks

Concrete shear walls are widely employed in buildings as a main resistance system against lateral loads. Early identification of seismic damage to concrete shear walls is vital for deciding post-earthquake occupancy in these structures. In this article, a method based on artificial neural networks for real-time identification of seismic damage to concrete shear walls was proposed. Inter-story drifts and plastic hinge rotation of concrete walls were used as the inputs and outputs of a MLP neural network. Modal Pushover Analysis was employed to prepare well-distributed data sets for training the neural network. The proposed method was applied to a five-story concrete shear wall building. The results from the network were compared with those obtained from Nonlinear Time History Analysis. It was observed that the trained neural network successfully detected damage to concrete shear walls and accurately estimated the severity of seismic-induced damage.     

An Analytical Study on the Seismic Vulnerability of Masonry Buildings in India

Two analytical models for unreinforced masonry (URM) buildings are proposed with the aim to simulate their seismic response and to estimate corresponding vulnerability functions. The proposed models are implemented in SAP 2000 nonlinear software to obtain capacity curve parameters for representative Indian URM buildings, based on a field survey and statistical analysis. Vulnerability functions are estimated using the obtained capacity curves. Damage Probability Matrices (DPMs) are obtained using the approximate PGA-intensity correlation relationship as per Indian seismic building code and are compared with the commonly used intensity scales and empirical damage data observed after the 2001 Bhuj earthquake.     

X-ray fluorescence analysis of late Roman and Sassanian silver plate

About 200 analyses have been made on late Roman and Sassanian silver objects using energy-dispersive X-ray fluorescence. This has shown that the main feature of the composition of the silver throughout the period and across the geographical area studied was towards high fineness (average silver percentage about 95%). Compositional differences are found between Roman and Sassanian silversmiths' products for the elements copper and lead. Much of the material analysed came from hoards, and using a statistical technique on the analytical data (Discriminant Analysis) broad compositional differences between hoards were found to emerge. The use of different compositions of silver for different joined parts of a single object are discussed.     

The White Marble of the Arch of Augustus (Susa,North‐Western Italy): Mineralogical and Petrographic Analysis for the Definition of its Origin

The Arch of Augustus in Susa (north‐western Italy) was built in 9–8 bc by King Cottius, to celebrate the treaty between the Romans and the Gauls. It is made of white marble, which was considered for a long time to be locally extracted, but no archaeometric studies have been performed up to now. Therefore, a multi‐analytical study based on petrographic (optical and scanning electron microscopy), electron microprobe and stable isotope analyses was carried out on the marble from the arch and from reference samples, with the aim of defining the provenance. All the data confirmed that white marble belonging to the metamorphosed carbonate cover of the Dora Maira Massif, known as Foresto marble, was used for the Susa Arch. This choice was probably made for economic reasons, but also due to the relative independence of the ruling family of the Alpes Cottiae, which was obviously interested in promoting a local marble.     

Collaborative Networks for Effective Ecosystem‐Based Management: A Set of Working Hypotheses

Ecosystem‐based management (EBM) represents a comprehensive approach to better govern the environment that also illustrates the collaborative trend in policy and public administration. The need for stakeholder involvement and collaboration is strongly articulated, yet how and for what purposes collaboration would be effective remains largely untested. We address this gap by developing and evaluating a set of hypotheses specifying how certain patterns of collaborations among actors affect their joint ability to accomplish EBM. Content analyses of management plans drawn from five EBM planning processes in Sweden are combined with analyses of the collaborative networks through which these plans have been developed. Our results indicate that system thinking and the ability to integrate across different management phases are favored by collaborations between different kinds of actors, and by project leaders being centrally located in the networks. We also find that dense substructures of collaboration increase the level of specificity in the plans in regards to explicating constraints on human activities. Having many collaborative ties does however not enhance the overall level of specificity. Our results also show that different network characteristics can give rise to similar EBM outcomes. This observed equifinality suggests there is no single blueprint for well‐performing collaborative networks.     

Development of Collaborative Structure Analysis (CSA) System and Its Application to Investigate Effects of Soil-Structure Interaction

In this article, a collaborative structure analysis (CSA) system is developed for integrating different finite-element simulation programs. In this system, a simulated structure is divided into multiple substructures, and the interaction between the substructures is considered. Interfaces for the commercial finite-element program ABAQUS and for an open-source framework for structure analysis, OpenSees, are developed to achieve CSA integration. The CSA system is applied to analysis of a soil-structure interaction (SSI) problem, and the effects of SSI are investigated, and the efficiency and accuracy of the system are demonstrated.