The production of social housing in an Amazonian city
CONFINS-REVUE FRANCO-BRESILIENNE DE GEOGRAPHIE-REVISTA FRANCO-BRASILEIRA DE GEOGRAFIA
Authors: de Oliveira, Jose Aldemir; de Souza, Crizan Graca
Abstract
This paper discusses the housing derived from public policies in cities located in the Brazilian Amazon and how these policies affects the lifehoods of local residents. It is shown that the geography of the cities that receive these projects becomes more complex. Interests of various agents producing the space seek to guarantee the extended reproduction of capitalist relations in the most distant places of the Amazon, especially in riverside cities. The results presented are based on extensive fieldwork done in Parintins, Amazonas state, during the years 2016 and 2017. The aim of the fieldwork was to identify the differences and similarities of the production of social housing in the city of Parintins comparing the first groups of housing projects financed by National Housing Bank (Banco Nacional de Habitacao - BNH) and the most recent ones by Federal Cashier (Caixa Economica Federal - CEF) through the My House My Life Program (Programa Minha Casa Minha Vida - PMCMV). The results have shown that the production of social housing implies in changes in space, such as the expansion of the city, the insertion of the housings into the urban structure, the rise in number of enterprises and urban equipments built. These results appear implicitly in questions that are difficult to quantify due to the fact that they go beyond the architectural forms and are related to the dimensions of the lifehoods.
Absence of a long-range ordered magnetic ground state in Pr3Rh4Sn13 studied through specific heat and inelastic neutron scattering
JOURNAL OF PHYSICS-CONDENSED MATTER
Authors: Nair, Harikrishnan S.; Ogunbunmi, Michael O.; Ghosh, S. K.; Adroja, D. T.; Koza, M. M.; Guidi, T.; Strydom, A. M.
Abstract
Signatures of absence of a long-range ordered magnetic ground state down to 0.36 K are observed in magnetic susceptibility, specific heat, thermal/electrical transport and inelastic neutron scattering data of the quasi-skutterudite compound Pr3Rh4Sn13 which crystallizes in the Yb3Rh4Sn13-type structure with a cage-like network of Sn atoms. In this structure, Pr3+ occupies a lattice site with D-2d point symmetry having a ninefold degeneracy corresponding to J = 4. The magnetic susceptibility of Pr3Rh4Sn13 shows only a weak temperature dependence below 10 K; otherwise remaining paramagnetic-like in the range, 10 K-300 K. From the inelastic neutron scattering intensity of Pr3Rh4Sn13 recorded at different temperatures, we identify excitations at 4.5(7) K, 5.42(6) K, 10.77(5) K, 27.27(5) K, 192.28(4) K and 308.33(3) K through a careful peak analysis. However, no signatures of long-range magnetic order are observed in the neutron data down to 1.5 K, which is also confirmed by the specific heat data down to 0.36 K. A broad Schottky-like peak is recovered for the magnetic part of the specific heat, C-4f, which suggests the role of crystal electric fields of Pr3+. A crystalline electric field model consisting of 7 levels was applied to C-4f which leads to the estimation of energy levels at 4.48(2) K, 6.94(4) K, 11.23(8) K, 27.01(5) K, 193.12(6) K and 367.30(2) K. The CEF energy levels estimated from the heat capacity analysis are in close agreement with the excitation energies seen in the neutron data. The Sommerfeld coefficient estimated from the analysis of magnetic specific heat is gamma = 761(6) mJ K-2 mol-Pr which suggests the formation of heavy itinerant quasi-particles in Pr3Rh4Sn13. Combining inelastic neutron scattering results, analysis of the specific heat data down to 0.36 K, magnetic susceptibility and, electrical and thermal transport, we establish the absence of long-range ordered magnetic ground state in Pr3Rh4Sn13.