To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This article presents the first archaeological survey of the ornate Kidichi baths on Zanzibar. The baths were built either for or by Shihrazad, a wife of Zanzibar’s nineteenth-century ruler Said bin Sultan (1806–56). Laser scanning the ornate plaster stucco clarified two inscriptions, the precise meaning of which had been lost. By combining archaeological survey results with historical research and a translation of the inscriptions, a new narrative is presented in which the main protagonist is, unusually, female. Her story raises a host of questions relating to heritage, gender, religion and politics in modern-day Africa and beyond.
The site of the Dzuun Khuree monastery in the Upper Kherlen Valley of eastern Mongolia was recently investigated by UAV and ground-penetrating radar. The monastery's highly unusual circular form and layout suggest a foundation earlier than previously suspected.
While palaeobotanical remains provide clear evidence for the exploitation of the date at various locations in Egypt and Nubia, it is the detection amongst lipid residues in closed form vessels of fatty acid distributions dominated by diagnostic short-chain fatty acids, i.e. C12:0 and C14:0′ that provides the first direct evidence for the processing of palm fruit in pottery vessels.
Micro-tensile specimens of coarse-grained Ti52at%Al crystals have been deformed in situ in a high voltage electron microscope at room temperature. In addition to some twinning, “simple” 1/2〈110] dislocations as well as superdislocations were moving, with the simple dislocations prevailing even if their orientation factor is lower than that of the superdislocations. Both types of dislocations are pinned, probably by small precipitates having a distance along the dislocations of about 100 nm. The precipitates consist most probably of Al2O3. Under stress, the dislocations bow out between the obstacles. The bowing is stronger for 1/2〈110] dislocations. An effective stress of about 41 MPa is estimated from their curvature. The kinematic behaviour of the dislocations is in accord with precipitation hardening. The dislocations are generated by the double-cross slip mechanism. Their density within the slip bands corresponds to a long-range internal stress of about 40 MPa. These data are consistent with the flow stress of PST crystals in the easy orientation, taken from the literature.
The stability of bcc-based phases in the Ti-Al-Nb alloy system has been studied from first-principles using a combination of ab-initio total energy and cluster variation method (CVM) calculations. Total energies have been computed for 18 binary and ternary bcc superstructures in order to determine low temperature ordering tendencies. From the results of these calculations a set of effective cluster interaction parameters have been derived. These interaction parameters are required input for CVM computations of alloy thermodynamic properties. The CVM has been used to study the effect of composition on finite-temperature ordering tendencies and site preferences for bcc-based phases. Strong ordering tendencies are observed for binary Nb-Al and Ti-Al bcc phases as well as for ternary alloys with compositions near Ti2AlNb. For selected superstructures we have also analyzed structural stabilities with respect to tetragonal distortions which transform the bcc into an fcc lattice. Instabilities with respect to such distortions are found to exist for binary but not ternary bcc compounds.
The history of early settlement of the East African coast is currently interpreted in widely differing ways. One view takes as its premise the idea that the coast was first colonized from Asia. This hypothesis, which has its roots in the work of XlXth century historians suggests that there was substantial settlement by non-Africans who established trading and religious communities. These colonies formed the basis of what has come to be known as the Swahili Culture. At first defensible peninsulas and offshore islands were chosen as safe refuges from the African tribes of the interior. Eventually contact was established between these new communities and the African coastal peoples, to the benefit of both parties. Raw materials were obtained from the hinterland of these trading outposts, which were traded and taken across the Western Indian Ocean on the seasonal monsoons. The foreign merchants married local African women and an Afro-Arab culture developed, building stone towns, mosques, and tombs, that still remain today along the coastline from Somalia to Mozambique.