Composition dependence of ion transport coefficients in gas mixtures

A simple momentum-transfer theory for the composition dependence of ion mobilities and diffusion coefficients in gas mixtures at arbitrary field strengths is corrected, extended, and compared with a similar theory based on momentum and energy transfer, and with results based on direct solution of the Boltzmann equation by Kihara's method. Final equations are recommended for predicting composition dependences, given only results on ion mobilities and diffusion coefficients in the pure component gases

The spatial construction of young people's livelihoods in rural southern Africa

Young people in southern Africa, in common with young people around the world, are social agents, constructing their own lives, albeit within significant structural constraints. Unlike young people in some regions, for most the need to generate a livelihood is a key consideration. Livelihood construction is a profoundly spatial activity, yet while there have been a number of studies of the spatial construction of young people's livelihoods in African cities, the spatiality of rural livelihoods has received less attention. Rural environments pose particular challenges for livelihood construction, and require particular spatial strategies. Four are discussed here: accessing education and training; migration for work; developing extensive social networks; and producing for markets. There are, however, aspects of the spatial structuring of rural southern African societies that seriously constrain the pursuit of productive livelihoods by young people. Two are considered: migration (for reasons unconnected with young people's livelihoods) and marriage practices

Creating futures for the past in southern Iraq: challenges and opportunities

Iraqi archaeologists and Assyriologists are desperate for communication and collaboration and intellectual challenge. Almost every colleague I meet in Iraq is keen to set up research partnerships and training programmes. Yet they are working in a vacuum, mostly isolated and unheard in their own country and beyond. There is little public discourse on local history and archaeology, and little Iraqi government understanding of the value of these matters in civic and cultural life. In this paper I explore how this situation come to be; why it is a matter of concern; and what, if anything, we as western academic historians, should try to do to about it. In the latter sections of the paper in particular, I do not try to be comprehensive but draw upon my own experiences and observations, in relation to the UK context in which I work. My aim is not simply to describe but to stimulate discussion, response and action

Rural young people's opportunities for employment and entrepreneurship in globalised southern Africa: The limitations of targeting policies

This paper is based on a study with rural young people in Malawi and Lesotho, focusing on their possibilities for accessing (self)employment in the face of the various constraints imposed by their poor rural situations. Participatory group exercises, combined with individual interviews in two rural villages, provided personal stories about jobs and businesses that the young people were engaged in, as well as previous experiences and future plans. Constraints, as well as enabling factors, working at both individual and structural levels were analysed. Policies intended to address the needs of young people tend to seek to target the most vulnerable, often on the basis of individual-and household-level characteristics (e.g. women, orphans and AIDS-affected households). We argue that this: (1) neglects the structural factors operating at national and global levels; and (2) fails to recognise that factors interact to produce vulnerability, rather than this being rooted in separate characteristics. We demonstrate that an intersectional approach, drawn from feminist studies, is a useful theoretical lens, which, in combination with a livelihoods perspective, helps illuminate the needs of rural young people. In situations characterised by high levels of poverty and multiple vulnerabilities, we argue that it can be costly and ineffective to try to decide 'who is most vulnerable'; rather, resources can be more effectively spent in trying to improve conditions that will benefit all rural young people

Notes on East African cowries

Volume: XX

Observations of cold dust in nearby elliptical galaxies

Spectral energy distribution (SED) analyses that include new millimeter to far-infrared (FIR) observations obtained with continuum instruments on the Nobeyama and James Clerk Maxwell Telescopes and the Infrared Space Observatory are presented for seven nearby (<45 Mpc) FIR-bright elliptical galaxies. These are analyzed together with archival FIR and shortwave radio data obtained from the NASA/IPAC Extragalactic Database (NED). The radio to infrared SEDs are best-fitted by power law plus graybody models of dust residing in the central galactic regions within a 2.4 kpc diameter and with temperatures between ~21 and 28 K, emissivity index simeq2, and masses from ~1.6 to 19 × 105 M☉. The emissivity index is consistent with dust constituting amorphous silicate and carbonaceous grains previously modeled for stellar-heated dust observed in the Galaxy and other nearby extragalactic sources. Using updated dust absorption coefficients for this type of dust, dust masses are estimated that are similar to those determined from earlier FIR data alone, even though the latter results implied hotter dust temperatures. Fluxes and masses that are consistent with the new FIR and submillimeter data are estimated for dust cooler than 20 K within the central galactic regions. Tighter physical constraints for such cold, diffuse dust (if it exists) with low surface brightness will need sensitive FIR to submillimeter observations with the Spitzer Space Telescope, SCUBA2, or ALMA

The clay tablet book in Sumer, Babylonia, and Assyria

After a brief survey of the mechanics, media, and cultural context of cuneiform writing, I take three case studies to try to determine whether – and, if so, when, where, and how – we can talk of books in the first three millennia of recorded human history in the Middle East. Writings from a school house from the eighteenth century bc city of Nippur show that Sumerian literary culture was primarily oral, with surviving tablets the ephemeral by-products of the memorization process. In seventh-century Nineveh, Assyrian king Ashurbanipal acquired his famous library through copying, inheritance, and wartime plunder as an assertion of imperial control. Five centuries later in Hellenistic Babylonia, chief-priest-to-be Shamash-êtir belonged to a tiny community of cuneiform-literate men who made celestial observations, calculations, and rituals in a last-ditch attempt to preserve traditional temple culture

Nebi Younus and Nimrud: report on a site visit made in April 2017

I visited the archaeological sites of Nebi Younus and Nimrud on Monday 3 April 2017 as a member of a group invited by Ms Layla Salih, who was then employed by the Iraqi State Board of Antiquities and Heritage to document the current state of heritage sites in Nineveh Province. At Nebi Younus the group included my colleague Dr Saad Eskander, several members of UNESCO Iraq, two ICONEM staff who were taking drone images of the site of UNESCO, two journalists from the New York Times, and archaeologist Dr Muzahim Mahmoud (Figure 1). At Nimrud the group consisted only of Ms Laylah Salih, Dr Saad Eskander, and the two ICONEM staff members, who were documenting the site by drone for UNESCO.1 The notes I present here represent my informal impressions only and should not be taken as definitive assessments. I am neither an excavation archaeologist nor a structural engineer, and I did not carry out systematic investigations of either site. Nor do I presume to recommend what should happen to either site now: that is for Iraqi experts and stake-holders to decide