Anisotropic susceptibility of the geometrically frustrated spin-chain compound Ca3Co2O6

Ca3Co2O6 is a system exhibiting a series of fascinating properties, including magnetization plateaus and remarkably slow dynamics at low-T. These properties are intimately related to the geometrical frustration, which results from a particular combination of features: (i) the chains are arranged on a triangular lattice; (ii) there is a large uniaxial anisotropy; (iii) the intrachain and interchain couplings are ferromagnetic and antiferromagnetic, respectively. The uniaxial anisotropy is thus an issue of crucial importance for the analysis of the physical properties of Ca3Co2O6. However, it turns out that no precise investigation of this magnetic anisotropy has been performed so far. On the basis of susceptibility data directly recorded on single crystals, the present study reports on quantitative information about the anisotropy of Ca3Co2O6.Comment: 10 pages, 5 figure

Grazing Fees: An Overview and Current Issues

Charging fees for grazing private livestock on federal lands is a long-standing but contentious practice. Generally, livestock producers who use federal lands want to keep fees low, while conservation groups and others believe fees should be increased. The formula for determining the grazing fee for lands managed by the Bureau of Land Management and the Forest Service uses a base value adjusted annually by the lease rates for grazing on private lands, beef cattle prices, and the cost of livestock production. The collected fees are divided among the Treasury, states, and federal agencies. Fee reform was attempted but not adopted in the 1990s. Current issues include instances of grazing without paying fees, efforts to retire certain grazing permits, and a broad approach to buy out grazing permittees. This report will be updated as needed

Magnetodielectric coupling in a Ru-based 6H-perovskite, Ba3NdRu2O9

A large spin-orbit coupling is a way to control strong magnetodielectric (MD) coupling in a higher d-orbital materials. However reports are rare on such compounds due to often leaky conductive behavior. Here, we demonstrate MD coupling in a Ru-based 6H-perovskite system, Ba3NdRu2O9. The rare-earth ion in a 6H-perovskite makes the system insulating enough to carry out MD investigation. The compound is ferromagnetically ordered below 24 K (TC), followed by another magnetic feature at T~ 17 K (T2). The dielectric constant clearly traces the magnetic ordering, manifesting a peak at the onset of TC, which is suppressed by the application of an external magnetic field (H). The results indicate the presence of MD coupling in this compound, which is further confirmed by the H-dependence of the dielectric constant. Interestingly, a cross-over of the sign of MD coupling is observed at T ~ T2. We conclude that two different mechanism controls the MD coupling which yields positive and negative coupling, respectively. Both mechanisms are competing as a function of temperature and magnetic field. This brings us a step closer to design and control the magnetodielectric effect in 6H-perovskites containing higher d-orbital elements

Labour challenges in Ethiopia’s textile and leather industries: no voice, no loyalty, no exit?

A state-led industrialization push inspired by the East Asian ‘developmental state’ model is at the centre of Ethiopia’s recent economic success. This model has historically proved potent for achieving rapid industrialization, but the business-state alliance at the heart of the model generally aimed to curb the power of labour. Focusing on textile and leather manufacturing in Ethiopia, this article addresses two questions: are workers capable of extracting gains from the process of industrialization, and have the actions of workers affected global value chain integration in the two industries? Our data shows that opportunities for collective voice among workers are limited. However, workers have expressed their discontent by leaving employers when working conditions fail to meet their expectations. The resulting turnover has generated significant obstacles for local and foreign firms attempting to participate in global value chains. In response, the Ethiopian state and employers implemented a number of measures, including restrictions on emigration and more generous non-wage benefits. Recent research on global value chains and labour highlights how workers are able to influence work practices through individual action. The present article builds on these ideas, but shows that firms and governments have the ability to respond and limit this power.Gatsby Charitable Foundation, Corpus Christi College at the University of Cambridge, the Cambridge Trust, and the Baxter et Alma Ricard Foundatio

Structure and electronic properties of the quasi-one-dimensional Ba₂Co₁₋ₓZnₓS₃ series

This work focuses on the structure and physical properties of the solid solution Ba₂Co₁₋ₓZnₓS₃ (0 ≤ x ≤ 1), a family of quasi-one-dimensional sulfides with end members Ba₂CoS₃ and Ba₂ZnS₃. The structure of selected compounds with increasing Zn²⁺ content has been analysed using, neutron diffraction, TEM and EXAFS and the physical properties via magnetic susceptibility and resistivity measurements. The progressive substitution of the non-magnetic Zn²⁺ cation for Co²⁺ rapidly destroys the antiferromagnetic transition present at 46 K in the quasi one-dimensional Ba₂CoS₃, leading to paramagnetic behaviour down to the lowest investigated temperature (5K) for compounds with x > 0.25. For compounds with x ≥ 0.4, a pure CW regime is recovered around 300 K, yielding effective moments consistent with the g factor of the tetrahedrally coordinated Co²⁺ previously determined for Ba₂CoS₃. The Zn²⁺/Co²⁺ substitution also removes the metallic-like behaviour of Ba₂CoS₃ causing an increase in the value of the resistivity with all the Ba₂Co₁₋ₓZnₓS₃ compounds showing semiconducting behaviour. The negative magnetoresistance of Ba₂CoS₃ is improved by the Zn²⁺/Co²⁺ substitution, with values of – 6% for Ba₂Co₀.₇₅Zn₀.₂₅S₃, – 9% for Ba₂Co₀.₅Zn₀.₅S₃ and – 8% for Ba₂Co₀.₂₅Zn₀.₇₅S₃. However, there does not seem to be a correlation between the values of the resistivity and the magnetoresistance and the content of Zn²⁺, leading to the hypothesis that transport properties may be linked more closely to extrinsic properties

Evaluation and Utilization of Policy Information in the Canadian Parliament: The Influence of External Policy Actors

While policy information utilization in the Public Service has been the subject of investigation, little is known in Canada about how legislators seek out knowledge or respond to information provided by external actors. Often described as lacking influence within the policy process, the average Canadian MP is assumed to engage little in policy-making. Based on a survey conducted amongst Members of the Canadian Parliament in April 2013, this paper investigates how MPs engage with both internal and external sources of information and what are some of the potential factors that explain MPs’ utilization of policy knowledge. Findings indicate that internal sources of information are the most regularly consulted, yet that amongst external providers, academic research is valued most highly. In line with recent literature on policy networks, results suggest that personal contact between policy actors is one of the most important mechanisms to ensure a positive reception of information. The overall conclusion is that MPs continue to have a strong interest in policy and respond positively to lobbying, whether these are the efforts of industry associations or academics disseminating their research

Caractérisation interférométrique du coefficient électro-optique de guides polymers intégrés

session affiches A7 " Instrumentation, Caractérisation et Capteurs " [A7.4]National audienceNous présentons ici une méthode de caractérisation de modulateurs électro-optiques en polymères par l'intermédiaire d'un Mach-Zehnder fibré. Les résultats obtenus par modulation de phase, dans une fibre optique soumise à des contraintes piézoélectriques, témoignent de la faisabilité de la méthode et montrent qu'une caractérisation avec une résolution satisfaisante est possible au moyen d'un procédé expérimental simple

Grazing Fees: An Overview and Current Issues

This report discusses fees for grazing private livestock on federal lands that is a long-standing but contentious practice. Generally, livestock producers who use federal lands want to keep fees low, while conservation groups and others believe fees should be increased