Combining finite element and finite volume methods for efficient multiphase flow simulations in highly heterogeneous and structurally complex geologic media

The permeability of the Earth's crust commonly varies over many orders of magnitude. Flow velocity can range over several orders of magnitude in structures of interest that vary in scale from centimeters to kilometers. To accurately and efficiently model multiphase flow in geologic media, we introduce a fully conservative node‐centered finite volume method coupled with a Galerkin finite element method on an unstructured triangular grid with a complementary finite volume subgrid. The effectiveness of this approach is demonstrated by comparison with traditional solution methods and by multiphase flow simulations for heterogeneous permeability fields including complex geometries that produce transport parameters and lengths scales varying over four orders of magnitude.     

The relationship between school ground design and intensity of physical activity

In this study, we investigated the relationship between school ground design and children's physical activity levels. In particular, we were interested in understanding the contribution of ‘green’ school ground design to physical activity levels. Data for this study were collected at an elementary school in Australia and in Canada. At each school, scans of Target Areas were completed to record the students' location and intensity of physical activity, based on the System for Observing Play and Leisure Activity in Youth (SOPLAY) (Australia: 23 scans, 6 Target Areas; Canada: 18 scans, 7 Target Areas). At both schools, the highest percentage of children present was engaged in vigorous physical activity on the manufactured equipment (42% of children/scan). Similarly, at both schools, the green area encouraged the highest percentage of children present to be engaged in moderate physical activity (47% of Australian children/scan, 51% of Canadian children/scan). The patterns of sedentary behavior differed slightly between countries. At the Australian school, the paved sporting courts (57%) and the paved canteen courtyard (50.5%) promoted the highest degree of sedentary play. At the Canadian school, the treed grassy berm (42%) and the treed concrete steps (43%) encouraged the highest percentage of sedentary behavior, followed by the open asphalt (34%). These results are also discussed in light of gender distribution. We conclude with a discussion of the design and cultural factors that influence children's physical activity on school grounds. We argue that if school grounds are to realize their potential to promote physical activity, they should include a greater diversity of design features and ‘green’ elements that engage children of varying interests and abilities in active play.     

Does it come from the Pays de Bray? Examination of an origin hypothesis for the ferrous reinforcements used in French medieval churches using major and trace element analyses

A new methodology based on major and trace element analyses of slag inclusions is proposed to determine (or exclude) the provenance of iron artefacts. It is applied to verify if the Pays de Bray, a French area between Rouen and Beauvais, could have been an important supplier for the ferrous reinforcements used in the Middle Ages for the building of churches and cathedrals in these two towns. To this purpose, the behaviour of trace elements during both direct and indirect operating chains is studied combining experimental smelting and different analytical methods, such as SEM–EDS, ICP–MS, LA–ICP–MS and INAA, performed on archaeological samples. The chemical signature of the Pays de Bray iron ore and slag is determined considering MnO and P₂O₅ contents as a first rough filter and seven couples of trace elements. Then, the major and trace elements are analysed using the same methods in the slag inclusions of 32 artefacts from the Beauvais and Rouen churches, made by the bloomery process. The trace element signature of the inclusions from each artefact is compared with the ore from the Pays de Bray area. The iron used in the Rouen and Beauvais churches seems not to come mainly from the Pays de Bray.     

The shell game: analytic problems in archaeological mollusc quantification

MNI calculations for archaeological molluscs that rely on counts of non-repetitive elements (NREs) are popular for their analytic speed and efficiency. Yet the reliability of this approach as compared to ‘traditionally’ calculated MNI has not been explored. Here, I examine these approaches using data from the Caribbean coastal midden site of Grand Bay, Carriacou. Results suggest that an NRE-based approach to MNI calculation can be unreliable under certain circumstances. In addition, dependence on the NRE-based method may hinder the integration of invertebrate with vertebrate data, obscuring a holistic understanding of prehistoric diet and resource exploitation. These findings are discussed in relation to practical constraints and fulfillment of zooarchaeological goals.     

Raw materials for medieval to post-medieval Tuscan glassmaking: new insight from LA-ICP-MS analyses

LA-ICP-MS analyses were performed on a set of Tuscan (post) medieval archaeological glass finds dated to the 13–16th century in order to quantitatively determine the trace element contents. The results are used for defining and distinguishing several compositional groups. The trace element data are consistent with the distinctions obtained by considering the major element data determined via quantitative SEM-EDX, but allow to obtain new insights into the nature and quality of the silica sources employed and the presumed method of ash purification.     

甘肃马鬃山区石板墓初步研究

2004年7月下旬至8月底,西北大学文化遗产与考古学研究中心和甘肃省文物考古研究所联合在甘肃肃北县马鬃山区进行了为期一个月     

上海松江区广富林遗址良渚时期人骨微量元素的初步研究

近几十年来,古代人群的食谱研究已经成为现代科技考古学的一个重要组成部分,也是当前国际科技考古学研究领域的一项前沿性课题。人类骨骼的化学元素分析为重建古代居民的食谱提供了大量信息。采用电感耦合等离子发射光谱仪(ICP-AES)对上海松江区广富林遗址良渚时期出土人骨中的Ba、Ca、Mg、Mn、P、Sr、Zn等7种化学元素测定的结果显示:发达的稻作业为该组居民提供了充足的植物性食物;而水网密集的周边环境同时又为该时期居民提供了丰富水产品,从而极大地补充了其蛋白质的摄入。     

Geochemical analysis of Late Classic and Post Classic Maya marketplace activities at the Plazas of Cobá, Mexico

Abstract

Lines of evidence for ancient exchange plazas may include trade routes and trade artifacts, urban open space near public structures, and rock alignments denoting market stalls, but regular patterns in soil chemical concentrations also point to marketplace use. We applied geochemical and geospatial analysis of the floors of the main Plaza of Group B and Plazas A, H, and J of Group D at Cobá, Mexico, to discover the chemical residues of phosphorus (P) and metals associated with the exchange of foodstuffs and mineral workshop items that may have been marketed there. The patterns of chemical residues in the floor of the Group B Plaza suggest ritual activities while the linear, parallel patterns of elevated Mehlich phosphorus and chelate extractable zinc concentrations in Plaza A support the hypothesis of market exchange at that location. Plaza H is associated with several Postclassic buildings, including the Pinturas Structure D-33. During the Postclassic period, Cobá had lost much of its population, though chemical residues from Plaza H are congruent with marketing. We argue that Plazas A and H were not permanent marketplaces but rather multi-purpose locations that also hosted large ceremonies.     

Synchrotron Radiation–Induced X‐Ray Fluorescence (SRXRF) Analyses Of The Bernstorf Gold

The gold finds from Bernstorf, in the Freising district of Bavaria, were discovered in 1998, in the area of a Bronze Age settlement. First analyses with X‐ray fluorescence (XRF) revealed gold of an unusually high purity grade, which was explained by the use of cementation techniques. A newer analysis with laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) indicated an even higher purity. The analytical results were the starting point of an ongoing discussion. In this study, we re‐analysed 11 gold samples with synchrotron radiation–induced X‐ray fluorescence at the BAMline at BESSY. In a thorough analysis, different excitation and detection conditions were applied to confirm or disprove the previous results. It was shown that the purity of the gold from the specimen is higher than 99.9%. The main impurities are silver in a range between 20 and 200 μg g^?1 and copper between 1 and 10 μg g^?1. The results are in very good agreement with the LA–ICP–MS measurements and provide basic information for discussions about provenance, processing techniques or considerations of authenticity.