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11.

In comparison with the teaching of most other geography topics, where fieldwork can be conducted relatively easily and seminars can be based on some pre-existing knowledge and first-hand experience of the issues, the range of resources and approaches available to tutors teaching the geography of development is necessarily more limited. Tutors often have to rely more heavily on 'top-down' teaching and more passive learning approaches, such as using videos, slides and lectures. While students may gain a theoretical understanding of development concepts, issues and problems, they may be left without a deeper 'experience' of such material. This paper describes a practical workshop designed to communicate to students the idea of 'appropriate technology'. The workshop enables students to actively 'experience' a development concept rather than simply understand it in theory. It tests comprehension and understanding, through the application of a concept to real examples, stimulates discussion and debate, and draws upon problem-solving and critical thinking skills.  相似文献   
12.
This study presents the results of multi-element analysis of weak-acid extractions of 953 soil samples collected by coring on and around pre-historic village sites on two islands, Sanak and Amaknak, in the eastern Aleutians. Concentrations of aluminum (Al), barium (Ba), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), strontium (Sr), titanium (Ti), and zinc (Zn) were determined using an inductively coupled plasma-mass spectrometer (ICP-MS). Resultant elemental signatures allow the identification of site features and organization in the absence of large-scale excavation. All the archeological sites showed similar and distinct chemical signatures regardless of the several thousand year date range of the sites or the length of time a site was occupied. However, intensity of occupation does appear to affect concentrations of elements. Site features such as houses, house berms, house floors and middens had distinct anthropogenic signatures and could be distinguished from one another. This approach may be used to identify sites that do not have distinct surface features and to target areas for excavation.  相似文献   
13.
The aim of this study was to apply Nakamura's technique to Valencia city center, after some preliminary tests in Barcelona. Previous studies of Barcelona had measured periods in restrictive conditions and in various types of material ranging from very soft soil (with a predominant period of approximately 2 s) to rock (0.3 s), and under different measurement conditions. The Valencia city center measurements were taken by using the distance from buildings and car and pedestrian traffic to construct a measurement grid that was as regular as possible. We also estimated possible soil-structure interaction to detect potential vulnerability.  相似文献   
14.
This work was aimed at developing a practical and simple settlement estimation of shallow foundation on liquefiable deposits. The study conducted a centrifuge test, a series of comprehensive numerical analysis, back analysis, equation calibration, and verification with data from not only centrifuge test but also the literature. It finally proposed a quick calculation method based on Meyerhof’s settlement equation (1965). A two-dimensional numerical analysis, named ALID, (Analysis for Liquefaction-induced Deformation), was employed for obtaining settlement of shallow foundations on liquefiable soils with different relative densities under various seismic conditions. Its performance was first verified through a centrifuge test conducted in this study. Then, the developed method based on Meyerhof’s settlement equation was employed, and a new parameter, NLR, was proposed to present the strength of liquefied soils by replacing N value in the original equation. The NLR was obtained through back analysis of the numerical results and modified accordingly after comparison with the data from the literature. This paper, finally, demonstrated the practical use of the proposed method involving NLR by predicting 199 sets of liquefaction-induced settlement of shallow foundation reported in the past, including a latest most liquefaction-induced settlement of a house in 0206 earthquake on February 6, 2016, in Taiwan.  相似文献   
15.
Analysis of detailed geomorphological mapping enables a sequence of glacial events to be established. An ice sheet whose source was to the west of the area of study is shown, by the suites of fluvioglacial landforms produced, to have down‐wasted in situ; meltwaters escaped beneath or through the ice, moving uphill across certain areas. Finally, a sub‐aerial drainage system was established and outwash terraces were spread down valley.  相似文献   
16.
The purpose of this study is to derive the attenuation relationships for PGA, PGV, and EPA parameters for areas within the seismic zones of Zagros, Alborz and Central Iran with rock and soil substructures. In order to do so, at first the available scientific data including the methods used for deriving attenuation relationships and the parameters involved have been gathered. Afterwards, all the efforts have been focused on gathering a thorough catalogue of earthquakes occurred in Iran. In this regard, a majority of the available catalogs in Iran have been gathered and corrected through different methods and finally a set of 89 earthquake events including 307 earthquake records with reliable data was chosen.

Since in order to derive the attenuation relationships it is essential to extract the parameters from the acceleration records, a great effort was placed on gathering the earthquake acceleration records of Iran. This resulted in building a database of a majority of the earthquake records up to the year of 2004. Afterwards, correction methods applicable to earthquakes records of Iran considering the type of machines used and the ground type were examined which resulted in certain guidelines for correction of earthquake acceleration record data related to Iran.

In the next step the needed parameters were extracted from the earthquake acceleration record data which were consequently divided into two seismic zones of Zagros, and Alborz and Central Iran according to tectonic conditions. After examination of the parameters and choosing the most appropriate among them, the attenuation relationships were derived for such parameters.  相似文献   
17.
This contribution describes the results and interpretations of geoarchaeological and palynological analyses of a soil profile near to a 14C dated Bronze Age roundhouse in a sub-peat field system at Belderg Beg, north Mayo in western Ireland, which displayed field-scale evidence of tillage in the form of cultivation ridges. This evidence of arable cultivation was supported by the presence of quernstones in the roundhouse, but there was no supporting evidence from other forms of socio-economic analysis. Soil micromorphological analysis was employed to define how the ridges were created and with what tools; pollen analysis was used to characterise the surface vegetation and test the purpose of the ridges. The results unequivocally showed that a phase of ard cultivation was followed after a brief hiatus by ridge-and-furrow tillage. There were tentative indications of possible amendment of the earlier, ard-worked soil, and more definitive evidence of midden material addition to the ridged soil. An AMS radiocarbon assay on the base of peat overlying the ridges indicated that tillage occurred in the Mid to Late Bronze Age.  相似文献   
18.
中国是一个森林资源比较贫乏的国家。更值得忧虑的是,几十年来,原本就十分贫乏的森林资源却遭到大规模的不合理的毁伐,面积缩减了24%。森林资源缩减,使生态环境严重恶化:旱涝灾害增加,土壤侵蚀严重,土地草原沙漠化,空气污染加剧,许多生物种类濒临灭绝。本文以大量数字和事实,尖锐而坦率地指出了我国人民面临的严峻问题,并提出了解决这一问题的方略。  相似文献   
19.
The object of this work was to relate the corrosion of tin-bronzes to the chemical condition of the soil in which they have been buried, most of them since the Bronze Age. Naturally, it was not easy to obtain recent hoards with their related soils, and considerable reliance had to be placed on recorded finds by taking recent soil samples from sites on which hoards were found over a hundred years earlier. Even so, with the exception of peat, a reasonable relationship appears to exist between the pH of the soil and the state of the metal. Acid soils are aggressive to metals and alkaline soils are benign. In no cases were sulphate reducing bacteria active in promoting corrosion. In the main, peat and peaty soils were benign in spite of their acidity, probably due to the protective action of polyphenols.  相似文献   
20.
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