Computed tomography study of snuff trays from San Pedro de Atacama (Northern Chile)

Wooden snuff trays from San Pedro de Atacama (SPA) in northern Chile are objects of particular museological value. Computed tomography (CT), a non-destructive analytical technique useful in the analysis of archaeological objects in which physical tampering is not desirable, was used to study provenience of wood, quality of craftmanship, taphonomic processes and nature of gemstone inlays in a group of snuff trays. While wood used in the manufacture of trays was mostly exogenous to SPA, gemstones used in inlays were likely of local origin. These findings support the active exchange of goods proposed for the south-central Andes region. Several features revealed in the trays support the view that craftsmen producing them were skillful artisans.     

On children's independent mobility: the interplay of demographic,environmental, and psychosocial factors

In the past 50 years, a marked reduction has occurred in European and North American children's freedom of movement and outdoor play. Using a structural equation model, the present study investigates the interaction between personal, environmental, and psychosocial factors that affect children's independent mobility. The study involved 313 mothers of 8–10-year-old Italian children. The results supported the hypothesized model: the age of the child, the maternal perception of social danger, and positive potentiality of outdoor autonomy were the most influential variables on children's independent mobility, measured as an index. Further, the maternal perceptions mediated the influence of the other demographic, psychosocial, and environmental variables on independent mobility.     

Potash - a key raw material of glass batch for Bohemian glasses from 14th-17th centuries?

The aim of this work is to verify or refute hypothesis of existence of basic/universal glass batch: quartz sand: potash: limestone, at a ratio of 2: 1: 1 used in Bohemian glass production since the middle ages onwards and to simulate the preparation of a potassium glass type with the composition used in medieval Bohemia. The chemical composition of Bohemian glass, which incorporated in the proposed glass batch for glassmaking on a laboratory scale, was evaluated by (a) findings directly related to glassmaking (samples from glasswork in Moldava dating back to the 15th century) and (b) information from publications.Experimentally produced glasses for the present paper were prepared from raw materials such as ash, leached ash, potash, limestone and quartz sand. The plant raw materials (spruce, beech and bracken ashes, raw and refined potash) were treated and prepared by methods similar to the production procedures used in the pre-industrial era.The main contrast was found in the CaO/K₂O weight ratio, which was determined in glasses that were characteristic of given periods. While this ratio was often below 1 in glasses of the 15th century, it reached values above 1 in glasses at the turn of the 16th-17th centuries. This result may indicate that the composition of the glass batch had changed.The results of the present study reject the current scholarly work dealing with glass batch composition during the 14th-17th centuries and confirm that glass produced in some Bohemian medieval glassworks could have been melted from a batch that included plant ash, making the use of limestone unnecessary. The traditional suggestion of the exact ratios of raw materials, often cited in historical literature, seems to be impossible. The glassmakers had to react to the variable composition of the raw materials, especially plant ash.     

Fuel, Fire and Heat: an experimental approach to highlight the potential of studying ash and char remains from archaeological contexts

As in traditional societies today ancient societies probably selected different fuels to meet specific heat requirements. Char and ash, the end products of fire, are often found in abundance in archaeological contexts. These end products can provide information regarding (i) the original fuel resource and type, (ii) the characteristics of the fire and (iii) combined with other archaeological evidence shed further light on possible socio-economic activity(-ies) associated with that fire. The three main fuel resources would have been (i) modern vegetation, (ii) fossil fuel and (iii) animal by-products. Local availability and abundance would have influenced the choice made.In this study an experimental approach was adopted to try and distinguish between the three different fuel resources that are known to have been used by ancient societies (and continue to be used by traditional societies today) from their char and ash remains to help determine original fuel-type and understand the relative heating properties. For this end one fuel-type from each fuel resource listed above, namely wood, peat and cow dung, was chosen.     

A PROCEDURE FOR COMBINING VERTICAL AND HORIZONTAL SEISMIC ACTION EFFECTS

The vertical component of earthquake ground motion has generally been neglected in the earthquake-resistant design of structures. This is gradually changing due to the increase in near-source records obtained recently, coupled with field observations confirming the possible destructive effect of high vertical vibrations.

In this paper, simple procedures are suggested for assessing the significance of vertical ground motion, indicating when it should be included in the determination of seismic actions on buildings. Proposals are made for the calculation of elastic and inelastic vertical periods of vibration incorporating the effects of vertical and horizontal motion amplitude and the cross-coupling between the two vibration periods. Simplified analysis may then be used to evaluate realistic vertical forces by employing the vertical period of vibration with pertinent spectra without resorting to inelastic dynamic analysis.

Finally, a procedure is suggested for combining vertical and horizontal seismic action effects which accounts for the likelihood of coincidence, or otherwise, of peak response in the two directions.     

STRUCTURAL REHABILITATION OF DAMAGED RC BUILDINGS AFTER THE 1 OCTOBER 1995 DİNAR EARTHQUAKE

This paper contains technical information related to the Dinar project for the rehabilitation of moderately damaged reinforced concrete buildings after the 1 October 1995 Dinar earthquake. The structural appraisal of the damaged buildings, analytical studies leading to decisions regarding structural rehabilitation or demolition, the supervision on site of the rehabilitation and the overall coordination of the project was entrusted to the Middle East Technical University Earthquake Engineering Research Center [METU-EERC] by the Turkish Ministry of Public Works and Settlement. The project involved the rehabilitation of 35 moderately damaged RC buildings with a total floor plan area of 22 000 square metres.     

FRAGILITY OF STANDARD INDUSTRIAL STRUCTURES BY A RESPONSE SURFACE BASED METHOD

National and international regulatory standards require industrial risk assessment, taking into account natural hazards including earthquakes, in the framework of Quantitative Risk Analysis (QRA). Seismic fragility analysis of industrial components may be carried out similarly as what has been done for buildings, even though some peculiar aspects require the development of specific tools. In the present paper a contribution to the definition of a rational procedure for seismic vulnerability assessment of standardised industrial constructions in a probabilistic framework is given. The method covers a range of components of the same structural type. Seismic reliability formulation for structures is used. Both seismic capacity and demand are considered probabilistic with the latter assessed by dynamic analyses. The application example refers to shell elephant foot buckling of unanchored sliding tanks. A regression-based method is applied to relate fragility curves to parameters varying in the domain of variables for structural design.     

BEHAVIOUR OF REHABILITATED STRUCTURAL WALLS

An experimental program for identifying the causes of failures in structural walls under earthquake loading and investigating potential rehabilitation schemes was undertaken. Large-scale models of the plastic hinge region of the walls were tested. An innovative test setup that provides the possibility of controlling the ratio of the shear force to both bending moment and axial load was constructed. A control wall was tested and failed prematurely in shear reproducing the failure observed in the field. Two different rehabilitation schemes to improve the behaviour of the wall using biaxial fibre reinforced polymer (FRP) sheets were designed to prevent the shear failure. To improve the ductility, the end column elements of the walls were confined using anchored FRP. The two schemes were tested and proved to be effective in increasing shear strength, ductility, and energy dissipation capacity of the walls.     

Direct Displacement-Based Design of Glulam Timber Frame Buildings

We introduce a direct Displacement-Based Design methodology for glued laminated timber portal frames with moment-resisting doweled joints. We propose practical expressions to estimate ultimate target displacement and equivalent viscous damping, and we demonstrate that these expressions provide prior values that are close to those obtained a posteriori using a more refined model. Applied to case studies, the method yields base-shear forces lower than those obtained using the force-based approach of Eurocode 8. This is due to the high dissipation capacity of the specific connection technology, which apparently is conservatively accounted for in the q-factor of Eurocode 8.     

Fuelwood,crops and acorns from Iritegi cave (Oñati,Basque Country)

Abstract

We present the analyses of plant macroremains from Iritegi, a cave from Northern Iberia with archaeological levels dated from the Chalcolithic to the Iron Age. Wood charcoal assemblages are dominated throughout the sequence by Fraxinus. Other important taxa are Quercus subg. Quercus, followed by Corylus avellana, Fagus sylvatica, Ilex aquifolium, Taxus baccata and Ulmus. Acer, Alnus and Maloideae occur in very low numbers. The high percentages of Fraxinus are possibly result from the selection of ash for fodder. Evidence for the use of crops (Hordeum vulgare, Triticum aestivum/durum) comes only from the Chalcolithic contexts. The identification of acorns in one Chalcolithic hearth shows that roasting of these nuts was taking place maybe to improve taste and to facilitate further processing or to improve storage conditions. The results show that plant food gathering still played a role within the subsistence of farming human groups in the region.