Investigating archaeological site formation processes on the battleship USS Arizona using finite element analysis

Scientists from the National Institute of Standards and Technology (NIST) worked in a collaborative partnership with archaeologists from the National Park Service's (NPS) Submerged Resources Center (SRC) to develop a finite element model (FEM) of the battleship USS Arizona. An FEM is a computer-based engineering model that calculates theoretical stresses, propagation of force, and shape changes to a structure under loads using thousands or even millions of individual elements whose individual responses are well understood. NIST researchers created an FEM of an 80 ft. (25 m) midships section of the Arizona site to analyze archaeological site formation processes on the sunken battleship, in particular to determine the current condition of the wreck and predict its future strength and structural integrity as it continues to corrode. The NIST's FEM study is one aspect of a larger project under the direction of the NPS, the USS Arizona Preservation Project, whose goal is to determine the nature and rate of corrosion affecting USS Arizona, and to model its long-term structural deterioration. The FEM incorporates findings from other key components of the USS Arizona Preservation Project, such as steel hull corrosion rates, structural surveys of the vessel, sediment compaction studies, and analysis of the concretion that covers the ship's hull, into a single tool that is being used to predict how the wreck will degrade in the future.     

Phytolith evidence for hearths and beds in the late Mousterian occupations of Esquilleu cave (Cantabria,Spain)

Esquilleu cave site has provided a moderately well preserved archaeological cave deposit from the Late Pleistocene in the Cantabrian area. Phytolith quantification, identification and determination of the refractive index have been carried out, together with FTIR analyses, from sediment samples collected in the profile. The comparison of the data obtained with the previous micromorphological results allows us to make inferences about the site formation processes and the Neanderthals use of the cave. Phytolith results show the presence of grass leaves nearby the hearth suggesting the repetitive existence of a bedding zone on the same area. Neanderthal behavioral patterns should be revised on the light of high resolution analyses, since diagenetic processes can obscure the existence of differentiated activity areas in the site.     

居民消费行为与城市生活空间行为规律研究

进入消费社会以后,社会经济的发展促使居民生活行为发生了很大的变化。消费作为居民日常生活的一部分,在社会空间秩序中起着越来越重要的作用。文章以\"人本主义\"地理学为出发点,应用数理统计和随机过程理论,结合影响居民消费行为的因素对居民消费行为的演进过程进行分析,来探讨城市居民消费行为与日常生活空间行为的关系,并总结出相应的居民消费生活空间行为规律。     

The role of scour in shipwreck site formation processes and the preservation of wreck-associated scour signatures in the sedimentary record – evidence from seabed and sub-surface data

Fully submerged shipwreck sites act as open systems, with the exchange of material (sediment, water, organic and inorganic objects) and energy (wave, tidal, storm) across system boundaries. Formation processes at wreck sites are driven by some combination of chemical, biological and physical processes, with physical processes dominant in initial phases of site formation. Scouring and associated depositional patterns that form in response to hydrodynamic forcing are commonly the dominant physical processes acting at shipwreck sites. Scour is initiated by the introduction of a shipwreck to the seafloor, leading to increases in flow velocity and turbulent intensity around the structure. Near-field and far-field scour pits form at wreck sites due to the interaction of horseshoe and lee wake vortices with the mobile substrate. The morphology of resultant scour signatures are controlled by the orientation of the wreck structure in relation to the prevailing hydrodynamic regime, the morphology and size of the wreck and individual site components, the hydrodynamic regime (currents, waves or combined waves and currents), bathymetry and the geology of the site (seafloor and sub-surface conditions). Individual objects or artefacts may act as nuclei to promote scour at a local scale. Under high-energy conditions, groups of artefacts and/or disarticulated structural components emanating from a wreck may compound natural scour processes by rolling or sliding. Under suitable environmental conditions, wreck-associated scour features can be preserved in the sedimentary record.     

Beyond the identification of formation processes: Behavioral inference based on traces left by cultural formation processes

Formation processes are generally considered as a negative factor for behavioral inference in archaeology. The concept of formation processes, however, can potentially be far more useful for behavioral inference in archaeology than simply identifying spurious variability in the archaeological record. Physical traces left by cultural formation processes convey a certain kind of behavioral information which may not be otherwise available. Variables related to site occupation, such as the occupation span, the number of occupation episodes, and the location of activities, can be inferred from characteristics of refuse deposits, or refuse structure.     

Solifluction-induced modifications of archaeological levels: simulation based on experimental data from a modern periglacial slope and application to French Palaeolithic sites

The taphonomic study of Petit-Bost, Croix-de-Canard and Cantalouette II, three Palaeolithic sites that were recently discovered near Périgueux and Bergerac (Dordogne, France) in a colluvial context, has enlightened the difficulty of adequately appreciating the relative role of cultural and natural processes in site spatial patterning. Periglacial solifluction was thought to have played a significant role in site formation. Because the nature of the modifications induced by solifluction was still poorly understood, a simulation was made using data of soil movement recorded at La Mortice (French Southern Alps, 3100 m in elevation) in a modern periglacial environment. The results show that, for a knapping location, the first steps of deformation are typified both by a downslope translation of the location center and by an anisotropic diffusion of the artifacts. The knapping spot becomes elongated along the slope, with a dense relic concentration of artifacts in the upslope portion. This type of pattern has been obtained after 100–200 years of simulated displacement according to the climatic and soil conditions that characterise the La Mortice site. The ultimate stages of deformation show that the artifact distribution tends to homogenise on larger surfaces and resemble a random distribution. The ability of the simulated patterns to closely fit those observed in archaeological contexts is evaluated at three sites from Southwestern France. At Petit-Bost, the hypothesis of limited solifluction explains accurately the association of both cultural (artifact concentrations) and natural (artifact preferred orientation) features. At Croix-de-Canard, long-term solifluction can be proposed. By contrast, the simulated patterns do not describe the structures observed on the steeper slopes at Cantalouette II, where the knapping spot transforms into distinct solifluction lobes.     

Expert‐Based Information and Policy Subsystems: A Review and Synthesis

This article reviews and synthesizes the uses of expert‐based information in policy subsystems. The review begins by summarizing the different uses of information in the multiple streams theory, the punctuated equilibrium theory, the social construction theory, and the advocacy coalition framework. Three uses of expert‐based information are identified as instrumental, learning, and political. The three uses of expert‐based information are then compared across unitary, collaborative, and adversarial policy subsystems. This article synthesizes the findings in a set of propositions about the use of expert‐based information in policy subsystems and about the factors that contribute to shifts from one policy subsystem to another.