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There are many healthcare facilities in Spain that were built throughout the second half of the 20th century, and compose an interesting built heritage designed by outstanding architects of the architectural avant-garde. Some of them were included in the DOCOMOMO's list of buildings to be preserved and documented. As a consequence, every intervention on the hospitals' heritage requires a special attention and needs a deep knowledge of the building in advance of taking action. On the other hand, such a particular heritage is being continuously updated according to the new standards that derive from the current tendencies in hospital design, and also from advances in healing techniques. In this context, 3D Modelling and virtual reality should have a decisive impact on the way hospitals' complex spaces are designed, as they become useful tools for describing the previous stages of the buildings, as well as the impacts of new proposals. They can even change our experience of the built environment. As a step forward, we are developing a methodology to be applied to hospital design where these tools, together with BIM models -and in the near future, high-end immersive VR systems- play an important role. [ABSTRACT FROM AUTHOR]

This manuscript presents evaluation of arsenic adsorption by carbon (Cb) and a carbonaceous material with iron nanoparticles (CbFe), coming from the pineapple peel (Ananas comosus (L.) Merr.) crown. Scanning electron microscopy results showed formation of three structures types in CbFe: spheres, filaments and spherical nanoparticles with an average diameter of 38 nm. CbFe material has a 167 m²/g specific area, 7±1 sites/nm2 site density and pHi = 11 isoelectric point, while Cb material presents values of 98.80 m²/g, 5 ± 1 sites/nm² and pHi = 10 ± 0.6, respectively. Arsenic adsorption was evaluated for both materials; the kinetic equilibrium was obtained at 8 h, removing 138.5 mg As/kg by CbFe and 96.95 mg As/kg by Cb. Experimental data were best adjusted to a pseudo-second order model, indicating that removal of As(V) due to a chemisorption process. The sorption isotherms were adjusted to model Freundlich with R² = 0.8797 and R² = 0.9671, respectively. Results showed that both materials are a viable option for arsenic (V) adsorption in aqueous phase. [ABSTRACT FROM AUTHOR]

This research presents a study of environmental monitoring at different sampling sites from the Metropolitan Area of the Valley of Toluca (MAVT), Mexico, using mosses (Leskea angustata (Tayl.) and Fabronia ciliaris (Brid.)) and soil samples. The epiphytic mosses and soils were sampled in two campaigns within two periods of the year, a rainy and dry-cold season. The selected sampling sites included urban regions (UR), transitional regions (TR), and protected natural areas (PA). The samples were analyzed by the Instrumental Neutron Activation Analysis (INAA) to determine As, Cr, Hg, and Se principally. However, due to the versatility of the analytic technique used, other elements including Cs, Co, Sc, Sb, Rb, Ce, La, Eu, and Yb were also detected. Statistical analysis (As, Cr, Hg, and Se) was carried out with principal components and cluster analysis methods; this revealed that a good correlation exists between metal content in mosses and the degree of pollution in the areas sampled. The obtained results in mosses showed that the concentrations of As, Cr, Co, Cs, Rb, Ce, La, and Yb increased with respect to the concentrations obtained during the first sampling, whereas Se, Sc, Sb and Eu, concentrations were decreased. For As and Hg, the concentrations were similar in both sampling periods. The soil samples present the most significant concentration. [ABSTRACT FROM AUTHOR]

Composite particles were synthesized using titanium oxide attached to polyethylene (TiOx-PE) films by plasma techniques and used for the removal of Cr(VI) from aqueous solutions in batch systems. The precursor to synthesize TiO was titanium tetrapropoxide (TTP) modified by collisions with accelerated particles in the plasma of water in order to separate the fractions of organic and inorganic TTPs that reorganize into small organometallic particles attached to the surface of PE. Before adsorption, the TiOx particles have spherical profiles agglomerated on the PE surface. The diameter was between 70 and 120 nm in agglomerates of around 500 nm; however, as the pH of the Cr solutions increased, the morphology of these particles changed to fibred patterns. The specific surface area was 163 m2/g, which is greater than that for commercial TiO2, and the pore size was 2.86 nm with a pore density of 0.11 cm3 g-1. The study results showed that the maximum Cr adsorption capacity (5.32 μg g-1) was obtained at pH = 3. The retention rate of Cr in the first minute was approximately 23%, and after 40 minutes, the rate reached up to 75%. During the adsorption process, a strong pH-dependent adsorption as a function of pH was observed. The adsorption kinetics of the TiOx-PE composites was studied using a pseudo-second-order model. The Cr(VI) experimental isotherm data were described by the Langmuir model. [ABSTRACT FROM AUTHOR]

Plasma polypyrrole was synthesized on stainless steel and Nitinol (Ni-Ti alloy) substrates in order to obtain polymermetal compounds with high adhesion. The work has the objective to cover metal surfaces with polymers to reduce the contact of metallic surfaces with biological tissues in human body implants. The metal samples were subjected to RF glow discharges with water vapor and argon to clean, oxidize and erode before the polymer coatings. After that, the synthesis of polymers was carried out by glow discharges during 10 min at 13.56 MHz, 10-1 mbar and 20 W. The results showed that the coating is carried out in consecutive thin layers with the morphology of the metal at the interface. The coated samples were immersed in phosphate solutions (PBS) pH = 7.4 to simulate the conditions of salt concentration in human arteries and veins. The PPy coated metal substrates have rough morphology with resistance to PBS solutions. However, Nitinol samples needed Ar besides water discharges to clean, oxidize and erode. [ABSTRACT FROM AUTHOR]

Abstract: The energy transfer at room temperature between Tb3+ and Eu3+ ions sorbed onto SrTiO3 powders is investigated, using Time-Resolved Laser-induced Fluorescence Spectroscopy (TRLFS). Several published works deal with the energy transfer between two lanthanide ions in co-doped matrices but it is the first time that transfer processes between two lanthanide ions sorbed on a solid surface is reported. The results show that the energy transfer between sorbed Tb3+ and Eu3+ ions on strontium titanate is a non-radiative process and follows a dipole–dipole type interaction. Moreover, the higher the acceptor ions Eu3+ concentration, the more efficient the energy transfer. It is shown that no energy migration between the Tb3+ donor ions occurs. A formalism based on the model of Inokuti–Hirayama is used and allows one to fit the non-exponential Tb3+ fluorescence decay. It is thus possible to evaluate the critical radius (R 0) of the influence sphere of the sorbed Tb3+ ions. According to the previous works, two sorption sites are considered for the sorbed rare-earth. The calculated radii are similar to those obtained for other couples of donor–acceptor lanthanide ions reported in the literature. [Copyright &y& Elsevier]

Abstract: The purpose of this work is the study of the interaction mechanisms between U(VI) ions and SrTiO3 surfaces as a function of pH and temperature (25, 50, 75 and 90 °C) by coupling thermodynamic and spectroscopic approaches. First, the reactivity towards U(VI) for both surface sites of the strontium titanate (ph name="sbnd" />O and ph name="sbnd" />O) has been investigated as a function of the temperature. The N2-BET specific area was measured: . The surface site density has been determined from potentiometric titrations (6 sites/nm2 for each site ph name="sbnd" />O and ph name="sbnd" />O). The potentiometric titration data have been simulated, for each temperature, using the FITEQL 4.0 software and the constant capacitance model, taking into account both protonation of the ph name="sbnd" />OH surface sites and deprotonation of the ph name="sbnd" />OH ones (one pK model). The intrinsic strontium protonation constant increases with an increasing temperature, while the titanate deprotonation one decreases. Moreover, both enthalpy and entropy changes corresponding to the surface acid–base reactions have been evaluated using the van''t Hoff relation. The uranium(VI) ions are sorbed onto SrTiO3 surfaces in the 0.5–5.0 pH range with an initial cation concentration equal to . The U(VI) surface complexes were identified by using time-resolved laser-induced fluorescence spectroscopy (TRLFS). For all the studied samples, the fluorescence spectra and the corresponding lifetime values do not change with the pH and the temperature. Two U(VI) complexes sorbed onto SrTiO3 were detected and the corresponding lifetimes are and whatever the temperature (25, 50, 75 and 90 °C). The sorption edges were simulated with the FITEQL 4.0 code. The sorption equilibrium constants of the U(VI)/SrTiO3 system between 25 and 90 °C were obtained with the constant capacitance model (CCM), considering two reactive surface sites. According to the spectroscopic characterization, two types of surface complexes, namely [(:glyph name="tbnd" />TiOH)UO2]2+ and [(:glyph name="tbnd" />TiO)UO2]2+, were considered. Finally, enthalpy () and entropy () changes were calculated from the temperature-dependent sorption constants, by the application of the van''t Hoff formalism. The formation of the [(:glyph name="tbnd" />TiOH)UO2]2+ surface complex was found to present an endothermic character associated to an increase in the disorder of the system. On the contrary, the formation of the [(:glyph name="tbnd" />TiO)UO2]2+ surface complex led to an exothermic process with only a slight increase in the disorder of the system. [Copyright &y& Elsevier]