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A majority of U.S. states have established a “Seal of Biliteracy” (SoBL) to recognize students’ multilingualism. Primarily under the purview of bilingual and world language education, the field of literacy research has remained largely silent on these seals. Yet, the authority these seals grant to state institutions for credentialing literacy has substantial implications for literacy research. This study analyzes 23 states that established a SoBL through legislative action. Informed by the study of seals as an ancient literacy practice, we draw on policy and visual discourse analysis to analyze state laws alongside the visual seals themselves. Incorporating theories of whiteness as property, we examine dynamics of racial, linguistic, and educational privilege to put forth a framework of biliteracy as property. Although we laud the growing popularity of the SoBL, we also caution against ceding authority to the state to assess, award, and “authenticate” biliteracy as a form of property.

Las investigaciones en microfinanzas, están referidas al servicio financiero orientado a grupos de población vulnerables, las cuales cada día enfrentan un panorama altamente competitivo. Bajo estas consideraciones, el presente artículo tiene como objetivo analizar las microfinanzas y su incidencia en el sector agrícola y comercial en Ecuador, particularmente las otorgadas por el Banco Pichincha C.A., de la Parroquia Rural Patricia Pilar. La metodología se orientó bajo un método cualitativo y cuantitativo. Los hallazgos evidencian que las microfinanzas apoyan de manera positiva al desarrollo del sector agrícola y comercial en el Ecuador, así como promueven la economía popular y solidaria, facilitando diversas formas de organización de la producción que responde a ventas anuales, ámbitos de ventas, y compra de mercadería; créditos otorgados por el banco; preferencias de los productos financieros; como también préstamos otorgados. Se concluye que las microfinanzas están reguladas en Ecuador de acuerdo con un marco institucional; sin embargo, es decisión de los microempresarios la búsqueda de estos instrumentos financieros que les ayuden a desarrollarse económicamente y ser más competitivos.

16th International Conference on Nanostructured Materials (NANO 2022), Sevilla, 6 -10 June 2022, Metasurfaces consisting of arrays of Au or Ag nanoparticles (NPs) on dielectric surfaces show unique optical properties related to the excitation of surface plasmon resonances (SPRs) that play a key role in the enhancement of fluorescence signals of active molecules, nanostructures, or surface Raman enhanced spectroscopy (SERS). In particular, SERS is becoming a key tool in areas such as molecular characterization, sensing, or detection of contaminants among others. However, a major drawback for the widespread use of SERS has been the lack of reliable practical techniques to produce solid substrates that could be used in sensors. This has frequently been related to the irreproducibility associated with the methods used to immobilize colloidal solutions of NPs into solid substrates. Therefore, a widespread use of SERS in these applications requires the development of reproducible SERS substrates having metal nanostructures with characteristic dimensions in the range of a few nanometers to tens of nanometers, and thus, different top-down and bottom-up approaches have been attempted. In this work we apply sequential pulsed laser deposition (PLD) to the synthesis of efficient SERS substrates consisting of Au NPs-Al2O3 metasurfaces. The as-deposited metasurfaces do not require any post-deposition treatment to show SERS activity, since PLD allows a precise control over the amount of deposited metal and an adequate range of interparticle spacing to enhance the SERS response. The characteristic Au NP size is close to 10 nm whereas the interparticle distance is in the 10-20 nm range. We compared the sensitivity in SERS of the produced metasurfaces with that of commercial ones produced by Langmuir-Schaefer technique and Klarite® substrates using the pesticide paraquat as a test molecule. The effect of the deposition time and the presence of Al2O3 on metasurface were tested by investigating the SERS efficiency when using the adenine molecule as a reference standard. The spectral differences observed between adenine deposited on a flat surface of Si and that of a PLD substrate and the SERS enhancement clearly indicates the existence of a SERS effect.

16th International Conference on Nanostructured Materials (NANO 2022) .-- Conferencia invitada, Metal-dielectric nanostructured films and surfaces present unique optical properties that make them ideal candidates for the development of optical and opto-electronic nanodevices, due to the possibility of generating a large electromagnetic field enhancement in the vicinity of the metal nanostructures (NSs) through localized surface plasmon resonances. However, most practical applications require a precise control of the morphology and organization of the metal NSs, since these characteristics define their optical behavior. In particular, the presence of non-spherical, ordered distributions of metal NSs allow a wider range of applications in fields other than optics, such as sensing or biomedicine among others. One interesting aspect for applications is that the achievement of nanostructures oriented in the direction perpendicular (nanocolumns, NCls) or parallel (nanowires, NWs) to the plane of the substrate makes controlled polarization effects possible, while a large aspect ratio (AR) intensifies the relevant mode of the plasmonic resonances and spectrally shifts it towards the optical communication wavelength range. In this work we apply sequential pulsed laser deposition (PLD) to the lithography-free synthesis of either NCls or NWs in a single-step. PLD allows a precise control over the amount of deposited metal, as well as reduced NSs size dispersion, yet the intrinsic characteristics of PLD make difficult the fabrication of metal NSs with well-defined shape and symmetry. We will show that the pulsed character of PLD, combined with an appropriate design of the deposition sequence and geometry, and the use of rippled substrates enable to produce self-assembled oriented Ag NCls and Au NWs having small diameters (DNCl¿3 nm, DNW ¿12 nm) and large aspect ratios (ARNCl¿20, ARNW ¿50). Optical characterization of the as-deposited nanostructures confirms a clear polarization dependence of the plasmonic resonant modes that is determined by the NSs¿ morphology and distribution. We will finally show the potential application of these NSs as omnidirectional polarizers.

Una de las problemáticas que el mercado de América Latina enfrenta es la escasez de recursos. La presente investigación tiene como objetivo analizar las condiciones que presenta el mercado de aceite vegetal proveniente de semillas oleaginosas, como el del Sacha Inchi, como producto alternativo al aceite de palma africana. La metodología utilizada está basada en un enfoque cuantitativo con alcances descriptivos, empleando una matriz de cálculo de la dinámica de apertura, cierre y supervivencia de empresas, para comprobar cuál de las variables como: Turbulencia, entrada bruta, salida bruta y entrada neta, incurren como condiciones de mercado para la demanda nacional del Sacha Inchi. El análisis de la dinámica sectorial permite medir niveles de incursión de nuevas empresas al sector agricultor de semillas, motivando a los microempresarios a adherir el Sacha Inchi a su producción. Se concluye que en el cantón La Concordia un 62,46% de empresas ingresan al sector durante los últimos 10 años con un promedio de vida de 8 años, siendo un sector atractivo para introducir la semilla de Sacha Inchi para la elaboración de aceite vegetal. Lo cual representaría un recurso alternativo para la actividad principal del cantón, como es la producción y siembra de palma africana.

2021 Spring Meeting of the European Materials Research Society (E-MRS) to be held as a VIRTUAL Conference from May 31st to June 3rd, 2021., Metal-dielectric nanostructures containing metal nanoparticles (NPs) present exciting optical properties, which make them ideal candidates for the development of nanoscale electronic and optical devices, due to the possibility of generating large electromagnetic field enhancement via Surface Plasmon Resonance (SPR). However, most practical applications require a fine control of the NP morphology and orientation. Sequential pulsed laser deposition (PLD) is a versatile technique which provides an excellent control over the amount of deposited metal, as well as reduced NP size dispersion. However, the Volmer-Weber nucleation and growth mode of metal NPs on a dielectric surface, along with surface processes, such as sputtering or sub-surface implantation associated to the presence of energetic ions in the laser generated plasma, hinder the production of NPs with well- defined symmetry. In this work, we show how these shortcomings can be tackled by exploiting the pulsed character of the PLD, appropriately designing the deposition sequence and geometry, and combining it with rippled substrates to produce oriented and elongated NPs along the direction of growth (nanocolumns, NCls) or parallel to the substrate plane (nanowires, NWs) with small diameters (D¿ 3 nm, D¿ 12 nm, respectively) and large aspect ratios (¿20 for NCls, ¿50 for Nos), that lead to a clear polarization dependence of the localized SPR modes. NUM. ADD

Symposium V: >Laser interactions with materials: from fundamentals to applications>, Nice, France, 27 to 31, 2019, Recently fluorescence-based techniques have gained great attention for detection of organic substances in small quantities for applications in environment control and health. Photonic technologies are in an excellent position to provide solutions in this context, since devices based on optical monitoring of light properties are very powerful tools for remote and non-invasive sensing applications. For these applications are necessary bright emitters that are clearly distinguishable and with a stable emission. In this respect rare-earth ions are very robust emitters with a very clean, narrow and robust emission. However, their emission tends to be less bright than that of traditional dyes due to their characteristic long-lifetime. A possible solution would be their combination with metallic nanostructures, particularly of Au and Ag, as they provide an enhanced emission due to plasmonic field absorption enhancement. In this work we investigate the modification of the emission luminescence properties of active thin films of europium oxide (Eu2O3) deposited on top of self-organized Au or Ag nanostructures prepared by Pulsed Laser Deposition (PLD). Au is investigated for its great stability for biological applications, while Ag is investigated due to the narrower band of its plasmon and its higher scattering efficiency. The potential enhancement of the emission efficiency is studied as a function of the deposition conditions, thickness and post-annealing treatments of Eu2O3 films.

Spring Meeting 2019. International Conference on Advanced Materials, Acropolis Congress Centre, Nice, France, May 27-31 2019, Transparent conductive oxides (TCO¿s) have been widely used as transparent electrodes for solar cells and mobile display panels because they present unique properties of coexistence of visible transparency and electronic conduction. One of the more used and extended is the Indium Tin Oxide (ITO), however Indium is scarce and this has motivated the investigation of new TCO¿s based on more abundant elements and with capability of tunable properties. In this context, molybdenum oxides are semiconductors with different optical and electronic properties depending on their stoichiometry: MoO3 presents transparency showing a wide bandgap (>3 eV), whereas MoO2 is a semimetal [1]. Upon introducing oxygen defects in MoO3, gap states can be generated effectively changing its response and allowing to the tunability of the material properties. In this contribution we will show the strategies that we are developing to deposit MoOx by PLD. We achieve the successful growth of MoOx films from a MoO3 target by using different starting background vacuum conditions. The films stoichiometry and therefore their optical response is further tuned by post-deposition annealing in air in up to 400ºC. We have studied the evolution of the dielectric function as a function of the deposition and post-annealing conditions in order to obtain films with optimized transparency.