Search results for "visual_art"
showing 10 items of 2987 documents
Mechanical and cohesion properties of brass plated steel cords in a sulphurizing environment
1986
The mechanical and cohesion properties of brass plated steel cords have been investigated in dry hydrogen sulphide between 25 and 450° C. The extents of elastic and plastic regions, obtained from slow strain rate technique data have been defined, and the preferential site of decohesion tends to be the brass-steel interface.
Common defects of parts manufactured through single point incremental forming
2021
Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final g…
Charcoal and stable soil organic matter as indicators of fire frequency, climate and past vegetation in volcanic soils of Mt. Etna, Sicily
2012
Abstract Charcoal fragments in soils are useful to reconstruct past vegetation because the level of preservation is often good enough to determine the tree genus. All forest ecosystems have the potential to burn as a result of naturally occurring or human-induced fires. Forest fires are coupled to climate and are a not-negligible factor of pedogenesis in Mediterranean areas, where they occur frequently. Furthermore, soil organic matter (SOM) is prone to undergo peculiar changes due to forest fires, both in terms of quantity and quality. A soil sequence along an elevational gradient ranging from Mediterranean to subalpine climate zones on slopes of Mt. Etna (Sicily, Italy) was investigated i…
Corema album archaeobotanical remains in western Mediterranean basin. Assessing fruit consumption during Upper Palaeolithic in Cova de les Cendres (A…
2019
[EN] Information about plant gathering by Palaeolithic hunter-gatherers in Europe is scarce because of the problems of preservation of plant remains in archaeological sites and due to the lack of application of archaebotanical analysis in many of them. Botanical macroremains wood charcoal, seeds, fruits, leaves, etc. - provide information not only about palaeoeconomy of hunter-gatherers, but also about climate, landscape and vegetation dynamics. In Gravettian and Solutrean levels of Cova de les Cendres (Alicante, Spain), Corema album pyrenes (Empetraceae or crowberries family) have been identified. On the contrary, wood charcoal of this species has not been documented among the remains of f…
Landscape and firewood procurement at the prehistoric and protohistoric site of Ses Païsses (island of Mallorca, Western Mediterranean)
2017
Abstract In this article we present the anthracological study of the settlement of Ses Paisses, located in north-eastern Mallorca (Balearic Islands, Western Mediterranean). A total of 25 charcoal samples have been analysed, corresponding to both concentrated (hearth and oven content) and dispersed charcoal fragments. The samples come from four different buildings of the settlement, each one showing different phases of occupation. The site presents a long sequence of occupation (from c.1212-1005 cal BC to the 1st century cal AD), expanding from the last centuries of the Bronze Age (Naviform), through the Early (Talayotic) and Late (Post-Talayotic) Iron Age up to the beginning of Roman occupa…
Marine debris ingestion in loggerhead sea turtles, Caretta caretta, from the Western Mediterranean
2002
Marine debris represents an important threat for sea turtles, but information on this topic is scarce in some areas, such as the Mediterranean sea. This paper quantifies marine debris ingestion in 54 juvenile loggerhead sea turtles (Caretta caretta) illegally captured by fishermen in Spanish Mediterranean waters. Curved carapace length was measured, necropsies were performed and debris abundance and type was recorded. Different types of debris appeared in the gastrointestinal tract of 43 turtles (79.6%), being plastics the most frequent (75.9%). Tar, paper, Styrofoam, wood, reed, feathers, hooks, lines, and net fragments were also present. A regression analysis showed that the volume of deb…
Review of paleo-humidity parameters in fossil rodents (Mammalia): Isotopic vs. tooth morphology approach
2014
Paleoecology of fossil rodents is frequently inferred from the dental pattern of the teeth, attributing the habitat conditions of extant rodents to fossil species with similar dental pattern. This technique is common practice and has been in use for several decades. A relatively new technique is based on the carbon and oxygen isotope composition of the incisor enamel of fossil rodents to reconstruct paleoenvironmental scenarios. We combine these two methods, studying material from two Early Miocene Spanish sections, one in the Mediterranean coastal area and one in Northcentral inland Spain. Comparison of the humidity values obtained by means of these two proxies reveals discrepancies. There…
Effects of traditional forest management on carbon storage in a Mediterranean holm oak (Quercus ilex L.) coppice
2018
Abstract: In the last decade, there has been increased interest in measuring and modeling storage in the five forest carbon pools: the aboveground and belowground biomass (living biomass), the deadwood and litter (dead biomass), and the soil (soil organic matter). In this paper, we examined carbon storage in a holm oak coppice stand in the Madonie Mountains in Sicily (Italy), which is a typical case of managed coppice stands. Today, traditional coppice practices are only applied to a small number of forested areas in Sicily, such as the selected site, because of the decline in demand for wood and charcoal. The dendrometric parameters of the stands were recorded, and silvicultural indices we…
Modelling dendro-anthracological parameters with dendrochronological reference datasets: interrogating the applicability of anthraco-typology to asse…
2020
International audience; Aleppo pine (Pinus halepensis Miller) is present in the palaeoenvironmental records of Mallorca (Balearic Islands, Western Mediterranean) since the Early Holocene. It is also documented in the archaeological charcoal analysis (aka anthracology) of early prehistoric sites, but it was especially exploited at certain sites during the Late Iron Age. However, different woodland exploitation strategies cannot be deciphered purely through the taxonomical identification of charcoal fragments, so it is difficult to assess if the presence of Aleppo pine in archaeological assemblages is due to specific social management strategies (branches and/or trunks exploitation). Anthraco…
A map of autumn precipitation for the third millennium BP in the Eastern Iberian Peninsula from charcoal carbon isotopes
2009
Abstract Carbon isotope composition (δ13C) in tree-rings has become routinely used in palaeoclimatic research for the assessment of changes in plant water availability in seasonally dry climates. However, the distribution of long tree-ring records around the world is very limited. Alternatively, the original climate signal of wood δ13C is well preserved in fossil charcoal and, accordingly, charcoal δ13C can be used to quantify past changes in water availability (e.g. precipitation). We report a case study on spatial palaeoclimate reconstruction which aims to characterize the transition between Bronze and Iron Ages, the so-called Iron Age Cold Epoch (ca. 900–300 BCE), using charcoals of Quer…