756 research outputs found

    The remittances behaviour of the second generation in Europe: altruism or self-interest?

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    Whereas most research on remittances focuses on first-generation migrants, the aim of this paper is to investigate the remitting behaviour of the host country-born children of migrants - the second generation - in various European cities. Some important studies found that migrant transnationalism is not only a phenomenon for the first generation, but also apply to the second and higher generations, through, among other things, family visits, elder care, and remittances. At the same time, the maintenance of a strong ethnic identity in the ‘host’ society does not necessarily mean that second-generation migrants have strong transnational ties to their ‘home’ country. The data used in this paper is from “The Integration of the European Second Generation” (TIES) project. The survey collected information on approximately 6,250 individuals aged 18-35 with at least one migrant parent from Morocco, Turkey or former Yugoslavia, in 15 European cities, regrouped in 8 ‘countries’. For the purpose of this paper, only analyses for Austria (Linz and Vienna); Switzerland (Basle and Zurich); Germany (Berlin and Frankfurt); France (Paris and Strasbourg); the Netherlands (Amsterdam and Rotterdam); Spain (Barcelona and Madrid); and Sweden (Stockholm) will be presented.

    Magnetic properties of the spin-1 chain compound NiCl3_3C6_6H5_5CH2_2CH2_2NH3_3

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    We report experimental results of the static magnetization, ESR and NMR spectroscopic measurements of the Ni-hybrid compound NiCl3_3C6_6H5_5CH2_2CH2_2NH3_3. In this material NiCl3_3 octahedra are structurally arranged in chains along the crystallographic aa-axis. According to the static susceptibility and ESR data Ni2+^{2+} spins S=1S = 1 are isotropic and are coupled antiferromagnetically (AFM) along the chain with the exchange constant J=25.5J = 25.5 K. These are important prerequisites for the realization of the so-called Haldane spin-1 chain with the spin-singlet ground state and a quantum spin gap. However, experimental results evidence AFM order at TN≈10T_{\rm N} \approx 10 K presumably due to small interchain couplings. Interestingly, frequency-, magnetic field-, and temperature-dependent ESR measurements, as well as the NMR data, reveal signatures which could presumably indicate an inhomogeneous ground state of co-existent mesoscopically spatially separated AFM ordered and spin-singlet state regions similar to the situation observed before in some spin-diluted Haldane magnets

    Magnetization steps in a diluted Heisenberg antiferromagnetic chain: Theory and experiments on TMMC:Cd

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    A theory for the equilibrium low-temperature magnetization M of a diluted Heisenberg antiferromagnetic chain is presented. The magnetization curve, M versus B, is calculated using the exact contributions of finite chains with 1 to 5 spins, and the "rise and ramp approximation" for longer chains. Some non-equilibrium effects that occur in a rapidly changing B, are also considered. Specific non-equilibrium models based on earlier treatments of the phonon bottleneck, and of spin flips associated with cross relaxation and with level crossings, are discussed. Magnetization data on powders of TMMC diluted with cadmium [i.e., (CH_3)_4NMn_xCd_(1-x)Cl_3, with 0.16<=x<=0.50 were measured at 0.55 K in 18 T superconducting magnets. The field B_1 at the first MST from pairs is used to determine the NN exchange constant, J, which changes from -5.9 K to -6.5 K as x increases from 0.16 to 0.50. The magnetization curves obtained in the superconducting magnets are compared with simulations based on the equilibrium theory. Data for the differential susceptibility, dM/dB, were taken in pulsed magnetic fields (7.4 ms duration) up to 50 T, with the powder samples in a 1.5 K liquid-helium bath. Non-equilibrium effects, which became more severe as x decreased, were observed. The non-equilibrium effects are tentatively interpreted using the "Inadequate Heat Flow Scenario," or to cross-relaxation, and crossings of energy levels, including those of excited states.Comment: 16 pages, 14 figure

    Superconductivity and Electronic Structure of Perovskite MgCNi3

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    The electronic structure, stability, electron phonon coupling and superconductivity of the non-oxide perovskite MgCNi3_3 are studied using density functional calculations. The band structure is dominated by a Ni dd derived density of states peak just below the Fermi energy, which leads to a moderate Stoner enhancement, placing MgCNi3_3 in the range where spin fluctuations may noticeably affect transport, specific heat and superconductivity, providing a mechanism for reconciling various measures of the coupling λ\lambda. Strong electron phonon interactions are found for the octahedral rotation mode and may exist for other bond angle bending modes. The Fermi surface contains nearly cancelling hole and electron sheets that give unusual behavior of transport quantities particularly the thermopower. The results are discussed in relation to the superconductivity of MgCNi3_3.Comment: 4 pages, RevTex, 5 ps figure

    Negotiating daughterhood and strangerhood: retrospective accounts of serial migration

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    Most considerations of daughtering and mothering take for granted that the subjectivities of mothers and daughters are negotiated in contexts of physical proximity throughout daughters’ childhoods. Yet many mothers and daughters spend periods separated from each other, sometimes across national borders. Globally, an increasing number of children experience life in transnational families. This paper examines the retrospective narratives of four women who were serial migrants as children (whose parents migrated before they did) . It focuses on their accounts of the reunion with their mothers and how these fit with the ways in which they construct their mother-daughter relationships. We take a psychosocial approach by using a psychoanalytically-informed reading of these narratives to acknowledge the complexities of the attachments produced in the context of migration and to attend to the multi-layered psychodynamics of the resulting relationships. The paper argues that serial migration positioned many of the daughters in a conflictual emotional landscape from which they had to negotiate ‘strangerhood’ in the context of sadness at leaving people to whom they were attached in order to join their mothers (or parents). As a result, many were resistant to being positioned as daughters, doing daughtering and being mothered in their new homes

    A Review of the Properties of Nb3Sn and Their Variation with A15 Composition, Morphology and Strain State

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    This article gives an overview of the available literature on simplified, well defined (quasi-)homogeneous laboratory samples. After more than 50 years of research on superconductivity in Nb3Sn, a significant amount of results are available, but these are scattered over a multitude of publications. Two reviews exist on the basic properties of A15 materials in general, but no specific review for Nb3Sn is available. This article is intended to provide such an overview. It starts with a basic description of the Niobium-Tin intermetallic. After this it maps the influence of Sn content on the the electron-phonon interaction strength and on the field-temperature phase boundary. The literature on the influence of Cu, Ti and Ta additions will then be briefly summarized. This is followed by a review on the effects of grain size and strain. The article is concluded with a summary of the main results.Comment: Invited Topical Review for Superconductor, Science and Technology. Provisionally scheduled for July 200

    Infrared Nonlinear Optics

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    Contains reports on six research projects.Defense Advanced Research Projects Agency Universities Research Initiative (Contract N00014-46-K-0760)Strategic Defense Initiative/Innovative Science & Technology, managed by the U.S. Naval Research Laboratory (Contract N00014-87-K-2031)National Science Foundation (Grant EET-87-18417

    ‘I think I'm more free with them'—Conflict, Negotiation and Change in Intergenerational Relations in African Families Living in Britain

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    While the family is increasingly being recognised as pivotal to migration, there remain too few studies examining how migration impacts on intergenerational relationships. Although traditional intergenerational gaps are intensified by migration, arguably there has been an over-emphasis on the divisions between ‘traditional’ parents and ‘modern’ children at the expense of examining the ways in which both generations adapt. As Foner and Dreby [2011. “Relations Between the Generations in Immigrant Families.” Annual Review of Sociology 37: 545–564] stress, the reality of post-migration intergenerational relations is inevitably more complex, requiring the examination of both conflict and cooperation. This article contributes to this growing literature by discussing British data from comparative projects on intergenerational relations in African families (in Britain, France and South Africa). It argues that particular understandings can be gained from examining the adaptation of parents and parenting strategies post-migration and how the reconfiguration of family relations can contribute to settlement. By focusing on how both parent and child generations engage in conflict and negotiation to redefine their relationships and expectations, it offers insight into how families navigate and integrate the values of two cultures. In doing so, it argues that the reconfiguration of gender roles as a result of migration offers families the space to renegotiate their relationships and make choices about what they transmit to the next generation

    The History You Don’t Know, and the History You Do: The Promise of Signature Pedagogies in History Education

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    The persistent separation of subject-matter content and pedagogical training in traditional teacher education programs has made it difficult for many beginning teachers to establish a base of knowledge they can use to develop pedagogical content knowledge as their careers unfold. While existing efforts to bridge this gap have focused on intensive collaborations between education faculty and their colleagues in disciplinary fields, or on the integration of disciplinary knowledge into teacher education coursework, work still can be done to address the problem of providing beginning teachers with the balance of deep and flexible content knowledge complemented by practical teaching maneuvers that so many of them crave. This chapter explores the possibility of addressing this gap via the development of signature pedagogies, following the lead established in many other professional fields, paying special attention to Lee Shulman’s conceptualization of the idea and its potential impact on teacher education in history

    Laboratory study on the mobility of major species in fly ash–brine co-disposal systems: up-flow percolation test

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    Apart from the generation of fly ash, brine (hyper-saline wastewater) is also a waste material generated in South African power stations as a result of water re-use. These waste materials contain major species such as Al, Si, Na, K, Ca, Mg, Cl and SO4. The co-disposal of fly ash and brine has been practiced by some power stations in South Africa with the aim of utilizing the fly ash to capture the salts in brine. The effect of the chemical interaction of the species contained in both fly ash and brine, when co-disposed, on the mobility of species in the fly ash–brine systems is the focus of this study. The up-flow percolation test was employed to determine the mobility of some major species in the fly ash–brine systems. The results of the analysed eluates from the up-flow percolation tests revealed that some species such as Al, Ca and Na were leached from the fly ash into the brine solution while some species such as Mg, Cl and SO4 were removed to some extent from the brine solution during the interaction with fly ash. The pH of the up-flow percolation systems was observed to play a significant role on the mobility of major species from the fly ash–brine systems. The study showed that some major species such as Mg, Cl and SO4 could be removed from brine solution using fly ash when certain amount of brine percolates through the ash.Web of Scienc
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