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It is essential that the society understands the importance of sustainable development, its implication for the existing living standards and the need to implement management policies that promote sustainability. Rehabilitation assumes a fundamental role in this process; however, we are faced with the lack of specific, adequate and simplified tools for the sustainability assessment in rehabilitation actions. In this paper, the analysis of different sustainability assessment systems was conducted, comparing them in order to identify the adjustments to be made to a Portuguese model taken under consideration. Subsequently, the model was cross-checked with current European and national urban rehabilitation and regeneration policies, analysing their contribution to sustainability, in order to define the assessment criteria and create a Simplified Method for the Sustainability Assessment for rehabilitation in old urban centres, which can be a useful tool, easy to use by all actors in the process and as a way of preserving the history of this areas, and the memory of those who inhabit them. This Method considers five major areas: Water, Energy, Materials, Emissions and Cultural, Economic and Social Environments. For each of these criteria, measurement indicators and levels of assessment were settled, adjusted to the context of old urban centres. [ABSTRACT FROM AUTHOR]

Single crystals of the Na2ThF6 hexafluor metallate were studied by polarized infrared reflectivity and Raman scattering. This compound belongs to the P321 (D32) space group and, contrary to most of the members of A2MX6 family, it is not characterized by ThF62− polyhedra but by trigonal tricapped prisms. Raman and infrared spectra were analyzed based on the factor group analysis and all the phonons at the Brillouin zone center were determined. Directional dispersion branches of the polar modes were calculated and used to identify polarization leaks and mixed excitations. [Copyright &y& Elsevier]

Abstract: The structural and electronic charge distributions of single-wall carbon nanotubes (SWNTs) chemically modified with Ag and CrO3 were investigated by ab initio methods. Using first-principles spin-polarized calculations, we studied the structural and electronic behavior of Ag atoms and CrO3 molecules interacting with an (8,0) semiconducting SWNT. We have found that the Ag atom behaves as an electron donor and the CrO3 as an electron acceptor in the presence of the SWNT. Resonance Raman experiments performed on Ag and CrO3-adsorbed SWNTs confirm the donor and acceptor behavior, respectively. [Copyright &y& Elsevier]

Abstract: The insertion of lithium atoms in the channels of the single-wall carbon nanotube (SWNT) bundles is investigated using an ab initio calculation. The relaxed structure as well as the electronic band structure were obtained. Results reveals that Li insertion modifies the band structure by shifting the Fermi level to a higher density of states region, and this shift scales with the rate of insertion. The Li/SWNT band structure allows to predict strongly modified electronic properties. [Copyright &y& Elsevier]

A single-crystal of peptide l -alanyl- l -alanine (C 6 H 12 N 2 O 3 ) was studied by Raman spectroscopy at low-temperature, and a tentative assignment of the normal modes was given. Evidence of a second order structural phase transition was found through Raman spectroscopy between the temperatures of 80 K and 60 K. Group theory considerations suggest that the transition leads the sample from the tetragonal to a monoclinic structure. Additionally, our study suggests that the mechanism for the structural phase transition is governed by the occupation of non-equivalent C 1 local symmetry sites by the CH 3 molecular groups. Analysis based on group theory suggests l -alanyl- l -alanine presents C 2 symmetry at low temperatures. [ABSTRACT FROM AUTHOR]

Abstract: This research reports a temperature-dependent Raman scattering study of dipotassium molybdate (K2MoO4) in the 18–913K temperature range. This study indicates that K2MoO4 crystal exhibits a temperature-induced first-order phase transition at around 578K from monoclinic phase to incommensurate phase. The phase transition is connected with tilting and/or rotations of the MoO4 tetrahedra that lead to a disorder in the MoO4 sites. An orthorhombic phase (α′-phase) of K2MoO4 was obtained when the low-temperature monoclinic structure was heated or when high-temperature hexagonal structure was cooled. A lattice dynamic calculation was performed by using the classical rigid ion model, in order to predict both wavenumbers and atomic displacements (eigenvectors) for the vibrational modes of the monoclinic phase of K2MoO4 and K2WO4. [Copyright &y& Elsevier]

Abstract: Hydrogen production from the dry reforming of methane has been studied over MAl2O4 (M=Cu2+, Ni2+ or both) with respect to the structure, surface properties and coke deposition of the spinel oxides. The catalysts were characterized by Raman, XPS, TEM, and N2 adsorption isotherms methods. The Nio/NiAl2O4 system was significantly more active due to the intimated contact between Nio specie and the NiAl2O4. This system is found to give carbon filaments which easily react with CO2, in comparison with the Cu-based spinel oxides. [Copyright &y& Elsevier]

Abstract: In this work, X-ray diffraction, Raman spectroscopy and differential scanning calorimetry techniques were used to understand the crystallization process on 20Li2O–80TeO2 glass. X-ray diffraction results reveal the presence of three distinct alpha γ-TeO2, α-TeO2 and α-Li2Te2O5 crystalline phases in the glass matrix. The Raman spectroscopy band structure of this glass is similar to the one observed in glassy TeO2. Raman results clearly reveal the metastable character of the γ-TeO2 phase in the 20Li2O–80TeO2 glass, whose associated vibration modes disappear completely at temperatures higher than 315°C. On the other hand, the Raman modes associated to α-TeO2 and α-Li2Te2O5 phases persists up to temperatures close to the final stages of the crystallization in the studied glass (around 420°C). From DSC measurements, the activation energies 296±3 and 298±1kJmol−1 were associated to γ-TeO2 and α-TeO2 phases crystallization, indicating that these phases crystallizes at temperatures very close in the studied glass. [Copyright &y& Elsevier]

Abstract: Polarized Raman spectra and polycrystalline spectra of isomorphous Sc2(MoO4)3 and Al2(WO4)3 crystals have been measured at room temperature and ambient pressure. Some Raman spectra of Sc2(MoO4)3 were taken at different values of pressures in the range of 0.0–3.0GPa. Lattice dynamics calculations have been performed on the orthorhombic phase (ambient phase) of these materials using a rigid ion model in order to calculate the phonon frequencies at the Brillouin zone Center (k =0). The calculated results fit qualitatively well the Raman spectra observed in these materials at room temperature and ambient pressure, and allowed us to establish their Raman signature. A higher coupling among the modes of the Al2(WO4)3 material compared with Sc2(MoO4)3 material was observed. The pressure dependent studies revealed that the 362 and 433cm−1 modes of Sc2(MoO4)3 and Al2(WO4)3, respectively, exhibit unusually high ∂ω/∂P values. The presence of these unstable modes in both materials is probably related to the mechanism of the phase transition from the monoclinic high-pressure phase to the unknown phase of lower symmetry. [Copyright &y& Elsevier]

Abstract: We have measured Raman and infrared spectra of α-Ge(HPO4)2·H2O compound at room temperature. The analysis of vibrational modes indicated the presence of two non-equivalent HPO4 2− units in agreement with 31P nuclear magnetic resonance measurements. A tentative assignment of all the observed modes is proposed based on the previous works reported for other hydrogenphosphate-based compounds. [Copyright &y& Elsevier]

Abstract: Single-wall carbon nanotubes (SWNTs) prepared by the arc discharge method were oxidized using nitric acid. The samples were analyzed by using Raman scattering and Fourier transformed infrared spectroscopy (FTIR). The FTIR results indicate the presence of –COOH acid groups in the treated samples. The up shifts observed in the radial breathing mode frequencies suggest that SWNTs behave as donors after the acid treatment, with charge transfer occurring from the nanotubes to the –COOH groups. Ab initio calculations of SWNTs interacting with –COOH acid groups support the charge transfer process from the nanotubes to the carboxyl groups. [Copyright &y& Elsevier]

We have investigated the behavior of the Li1.43Cs0.57SO4 single-crystal Raman spectra and dielectric permittivity as a function of temperature. It was observed that the crystal, which is an occupationally disordered system, with orthorhombic C2v2 structure at room temperature, undergoes a phase transition at 230 K. In the new phase the SO4 tetrahedra remain in two non-equivalent sites and there is no evidence of the doubling of the unit cell. [Copyright &y& Elsevier]