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991.
The joint application of electric and magnetic techniques for near-surface exploration represents a very useful tool for archaeological investigation and can provide a quantitative contribution to describe the spatial distribution of buried objects. In this work we show a new advanced tomographic approach, based on the parallel inversion of magnetic and electric observed data, aimed at the reconstruction of the subsoil of a still unexplored area of the archaeological site of Pompeii (Southern Italy). The survey was performed in collaboration with Pompeii's Archaeological Commission. The comparison between the results obtained from the tomographic inversions of both electrical and magnetic data was carried out in terms of the data inversions, which allowed us to obtain information about the location of the buried geophysical sources in the investigated subsoil. The results obtained seem to be in a good agreement, both for the position of the geophysical sources and for their dimensions. 相似文献
992.
Dysentery was a significant cause of ill health during medieval times according to written sources of the period. However, it has been very difficult to detect the organisms that cause dysentery in archaeological samples from latrines and cesspools. This is because the cysts of the enteric parasites that cause dysentery are very small and usually fragment in the soil, in contrast to the robust ova of parasitic intestinal worms. This study uses a monoclonal enzyme-linked immunosorbent assay (ELISA) technique to identify the fragments of those enteric parasites that cause diarrhoea. Samples were taken from two excavated medieval latrines in the city of Acre. Coins and radiocarbon dating suggest that the latrines were in use during the thirteenth century CE. Positive results were noted for Entamoeba histolytica and Giardia duodenalis, while Cryptosporidium parvum was negative. This is the first time that either of these parasites have been identified in the Middle East using these methods. 相似文献
993.
A. SANTAGOSTINO BARBONE E. GLIOZZO F. D’ACAPITO I. MEMMI TURBANTI M. TURCHIANO G. VOLPE 《Archaeometry》2008,50(3):451-473
SEM–EDS, EMPA, ICP–MS and ICP–OES were applied to the study of three sectilia panels made of red, orange and yellow glass slabs. In order to determine the chemical state of Cu, XAS was also performed. The results indicate that, with the exception of the red samples, all slabs were made by mixing a siliceous sand with natron. The red slabs show significant compositional differences with respect to K2O and MgO contents, probably linked to the use of plant ashes as a source of alkali. The red, orange and yellow slabs are coloured by metallic copper, cuprite and Pb antimonates, respectively. The comparison between the chemical composition of the Faragola samples and several glass reference groups did not provide conclusive evidence of provenance. 相似文献
994.
Elizabeth R. Chilvers Abigail S. Bouwman Keri A. Brown Robert G. Arnott A. John N.W. Prag Terence A. Brown 《Journal of archaeological science》2008,35(10):2707-2714
Attempts were made to detect ancient DNA (aDNA) in samples of 88 human skeletons from eight Neolithic and Bronze Age sites in Greece and Crete. Ancient DNA was absent in specimens from Nea Nikomedia, Lerna, Karaviádena (Zakro), Antron Grave Circle A and Mycenae Grave Circle A. For each of three skeletons from Antron Grave Circle B that were sampled, polymerase chain reactions (PCRs) gave products for nuclear but not mitochondrial DNA, but amplicon yield was low and inconsistent with replicate PCRs failing to give reproducible results. With specimens from Mycenae Grave Circle B, evidence for mitochondrial aDNA was obtained for four of the 22 skeletons that were studied, and at Kouphovouno evidence for mitochondrial and/or nuclear aDNA was obtained with eight of the 20 skeletons that were examined. We conclude that, although aDNA might be present in some Eastern Mediterranean skeletons from later centuries of the Bronze Age, it is not commonly found in material from this period and is likely to be absent from older material. 相似文献
995.
Combining an analysis of the compliance incentives faced by firms in an emissions trading program, a comprehensive review of the enforcement strategies employed in Sulfur Dioxide Allowance and the Regional Clean Air Incentives Market (RECLAIM) programs, and a review of the compliance performance of these programs thus far, we are able to propose several practical guidelines for enforcing emissions trading programs. We stress the importance of prevailing market prices for emissions permits in determining compliance incentives, the importance of accurately measuring firms' emissions, and the importance of implementing enforcement strategies that remove the incentives firms may have to falsify emissions reports. 相似文献
996.
Catherine S. Dolan 《Development and change》2002,33(4):659-681
This article examines the social effects of contract farming of export horticulture among smallholders in Meru District, Kenya. During the 1980s and 1990s, contracting was popularized by donors and governments alike as a way to reduce poverty and increase opportunities for self–employment in rural areas. Considerable research has documented the tensions in social relations that emerge in such cases, giving rise to gendered struggles over land, labour, and income in the face of new commodity systems. This article highlights similar tendencies. It suggests that men’s failure to compensate their wives for horticulture production has given rise to a string of witchcraft allegations and acts, as the wealth engendered by horticultural commodities comes up against cultural norms of marital obligation. While witchcraft accusations can expose women to risks of social alienation and financial deprivation, witchcraft nevertheless remains a powerful weapon through which women can level intra–household disparities and, more broadly, challenge the legitimacy of social practice. In Meru, witchcraft discourses are a vehicle through which gendered struggles over contract income are articulated and contested, and through which the social costs of agrarian transition become apparent. 相似文献
997.
Using a set of interregional input‐output tables built by Guilhoto (1998) for 1995 for two Brazilian regions (Northeast and rest of the economy), the methodology developed by Sonis, Hewings, and Miyazawa (1997) is applied in the construction of a series of linkages such that it is possible to examine, through the nature of the internal and external interdependencies, the structure of trading relationships between the two regions. The methodology uses a partitioned input‐output system and exploits techniques that produce left and right matrix multipliers of the Leontief Inverse. This procedure facilitates the classification of the types of synergetic interactions within a preset pairwise hierarchy of economic linkages subsystems. In general, the results show that the Northeast region has a greater dependence on the rest of the economy region than the rest of the economy has on the Northeast region, and at the same time the rest of the economy region seems to be more developed as it presents a more complex productive structure than the Northeast region. 相似文献
998.
Justin C. Williams 《Geographical analysis》2002,34(4):330-349
The land acquisition problem is a spatial partitioning problem that involves selecting multiple parcels to be acquired for a particular land use. Three selection criteria are considered: total cost, total area, and spatial contiguity. Achieving contiguity or connectivity has been problematic in previous exact methods for land acquisition. Here we present a new zero‐one programming model that enforces necessary and sufficient conditions for achieving contiguity in discrete cell landscapes, independent of other spatial attributes such as compactness. Computational experience with several demonstration problems is reported, and results and extensions are discussed. 相似文献
999.
Equations of state for basin geofluids: algorithm review and intercomparison for brines 总被引:1,自引:0,他引:1
Physical properties of formation waters in sedimentary basins can vary by more than 25% for density and by one order of magnitude for viscosity. Density differences may enhance or retard flow driven by other mechanisms and can initiate buoyancy‐driven flow. For a given driving force, the flow rate and injectivity depend on viscosity and permeability. Thus, variations in the density and viscosity of formation waters may have or had a significant effect on the flow pattern in a sedimentary basin, with consequences for various basin processes. Therefore, it is critical to correctly estimate water properties at formation conditions for proper representation and interpretation of present flow systems, and for numerical simulations of basin evolution, hydrocarbon migration, ore genesis, and fate of injected fluids in sedimentary basins. Algorithms published over the years to calculate water density and viscosity as a function of temperature, pressure and salinity are based on empirical fitting of laboratory‐measured properties of predominantly NaCl solutions, but also field brines. A review and comparison of various algorithms are presented here, both in terms of applicability range and estimates of density and viscosity. The paucity of measured formation‐water properties at in situ conditions hinders a definitive conclusion regarding the validity of any of these algorithms. However, the comparison indicates the versatility of the various algorithms in various ranges of conditions found in sedimentary basins. The applicability of these algorithms to the density of formation waters in the Alberta Basin is also examined using a high‐quality database of 4854 water analyses. Consideration is also given to the percentage of cations that are heavier than Na in the waters. 相似文献
1000.
Bruno E. J. S. Werz 《International Journal of Nautical Archaeology》2002,31(1):89-98
During the last few decades, Cape Town Castle has been extensively renovated. Parallel to this, a series of archaeological excavations were undertaken under the auspices of different institutions. During the course of these, it became clear that one specific site needed to be approached in a rather unorthodox way. This site, the main well situated in the centre of the previous headquarters of the Dutch East India Company at the Cape of Good Hope, was filled with water. Owing to its inaccessibility and other constraints, which made the application of adapted excavation techniques necessary, the need arose to call in the assistance of a diver-archaeologist. This article describes the approach to fieldwork undertaken in the Kat well during 1989 and 1999 and some of this feature's structural details. 相似文献