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Revisión de las diversos períodos de ocupación del foro de Pollentia, desde sus inicios en el primer cuarto del siglo I a.C. hasta la época islámica, destacando las reformas documentadas para época alto imperial y las del siglo III d.C, con especial atención al recinto fortificado que se construyó en época tardía en el antiguo foro de la ciudad.

En este artículo se intenta dar una visión muy somera de la evolución de los estudios de época romana en la isla de Mallorca (Baleares) que a lo largo de los años se han ido desarrollando, y cómo han estado siempre conectados con las diversas corrientes generales de estudios de la romanidad

To improve the thermochemical energy storage (TCS) behavior of Mn 2 O 3 , several Mn-Mo oxides with varying amounts of MoO 3 (0-30 wt%) were prepared by a precipitation method. The physico-chemical properties of the solids were studied by N 2 adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), and H 2 -temperature-programmed reduction (TPR), while their TCS behavior was determined by thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC). Apart from Mn 2 O 3 and MoO 3 phases, XRD revealed a mixed MnMoO 4 phase for MoO 3 loadings equal or higher than 1.5 wt%. All samples showed a well-formed coral-like surface morphology, particularly those solids with low MoO 3 contents. This coral morphology was progressively decorated with compact and Mo-enriched MnMoO 4 particles as the MoO 3 content increased. TPR revealed that the redox behavior of Mn 2 O 3 was significantly altered upon addition of Mo. The TCS behavior of Mn 2 O 3 (mostly oxidation kinetics and redox cyclability) was enhanced by addition of low amounts of Mo (0.6 and 1.5% MoO 3 ) without significantly increasing the reduction temperature of the solids. The coral morphology (which facilitated oxygen diffusion) and a smoother transition from the reduced to oxidized phase were suggested to be responsible for this improved TCS behavior. The samples containing 0.6 and 1.5 wt% of MoO 3 showed outstanding cyclability after 45 consecutive reduction-oxidation cycles at high temperatures (600-1000 °C). These materials could potentially reach absorption efficiencies higher than 90% at concentration capacity values typical of concentrated solar power plants.

Materials with the formula Sr 2 CoNb 1-x Ti x O 6-δ (x=1.00, 0.70; δ=number of oxygen vacancies) present a cubic perovskite-like structure. They are easily and reversibly reduced in N 2 or Ar and re-oxidized in air upon heating. Oxidation by water (wet N 2 ), involving splitting of water at a temperature as low as 700 °C, produces hydrogen. Both compounds displayed outstanding H 2 production in the first thermochemical cycle, the Sr 2 CoNb 0.30 Ti 0.70 O 6-δ material retaining its outstanding performance upon cycling, whereas the hydrogen yield of the x=1 oxide showed a continuous decay. The retention of the materials' ability to promote water splitting correlated with their structural, chemical, and redox reversibility upon cycling. On reduction/oxidation, Co ions reversibly changed their oxidation state to compensate the release/recovery of oxygen in both compounds. However, in Sr 2 CoTiO 6-δ , two phases with different oxygen contents segregated, whereas in Sr 2 CoNb 0.30 Ti 0.70 O 6-δ this effect was not evident. Therefore, this latter material displayed a hydrogen production as high as 410 μmol H 2  g -1 perovskite after eight thermochemical cycles at 700 °C, which is among the highest ever reported, making this perovskite a promising candidate for thermosolar water splitting in real devices., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Multimode interference (MMI) waveguides can be used to create wavelength-dependent spot patterns which enables simultaneous analyte detection on a single optofluidic chip, useful for disease diagnostics. The fidelity of such multi-spot patterns is important for high sensitivity and accurate target identification. Buried rib structures have been incorporated into these SiO 2 -based waveguides to improve environmental stability. Through experiments and simulation, this letter explores design parameters for a buried MMI rib waveguide based on anti-resonant reflecting optical waveguides in order to produce high-fidelity spot patterns. Optimal rib heights and widths are reported in the context of available microfabrication etch technology and performance for an optimized biosensor is shown.

Multimode interference (MMI) waveguides can be used for multiplexing and de-multiplexing optical signals. High fidelity, wavelength dependent multi-spot patterns from MMI waveguides are useful for sensitive and simultaneous identification of multiple targets in multiplexed fluorescence optofluidic biosensors. Through experiments and simulation, this paper explores design parameters for an MMI rib anti-resonant reflecting optical waveguide (ARROW) in order to produce high fidelity spot patterns at the liquid core biomarker excitation region. Width and etch depth of the single excitation rib waveguide used to excite the MMI waveguide are especially critical because they determine the size of the input optical mode which is imaged at the MMI waveguide's output. To increase optical throughput into the MMI waveguide when light is coupled in from an optical fiber, tapers in the waveguide width can be used for better mode matching.

Water absorption was studied in two types of waveguides made from unannealed plasma enhanced chemical vapor deposition (PECVD) SiO 2 . Standard rib anti-resonant reflecting optical waveguides (ARROWs) were fabricated with thin films of different intrinsic stress and indices of refraction. Buried ARROWs (bARROWs) with low and high refractive index differences between the core and cladding regions were also fabricated from the same types of PECVD films. All waveguides were subjected to a heated, high humidity environment and their optical throughput was tested over time. Due to water absorption in the SiO 2 films, the optical throughput of all of the ARROWs decreased with time spent in the wet environment. The ARROWs with the lowest stress SiO 2 had the slowest rate of throughput change. High index difference bARROWs showed no decrease in optical throughput after 40 days in the wet environment and are presented as a solution for environmentally stable waveguides made from unannealed PECVD SiO 2 .