Modeling of Mid-IR Amplifier Based on an Erbium-Doped Chalcogenide Microsphere

An optical amplifier based on a tapered fiber and an Er3+-doped chalcogenide microsphere is designed and optimized. A dedicated 3D numerical model, which exploits the coupled mode theory and the rate equations, is used. The main transitions among the erbium energy levels, the amplified spontaneous emission, and the most important secondary transitions pertaining to the ion-ion interactions have been considered. Both the pump and signal beams are efficiently injected and obtained by a suitable design of the taper angle and the fiber-microsphere gap. Moreover, a good overlapping between the optical signals and the rare-earth-doped region is also obtained. In order to evaluate the amplifier performance in reduced computational time, the doped area is partitioned in sectors. The obtained simulation results highlight that a high-efficiency midinfrared amplification can be obtained by using a quite small microsphere

Integrated Models of Care for Individuals with Opioid Use Disorder: How Do We Prevent HIV and HCV?

Purpose of Review To describe models of integrated and co-located care for opioid use disorder (OUD), hepatitis C (HCV), and HIV. Recent Findings The design and scale-up of multidisciplinary care models that engage, retain, and treat individuals with HIV, HCV, and OUD are critical to preventing continued spread of HIV and HCV. We identified 17 models within primary care (N = 3), HIV specialty care (N = 5), opioid treatment programs (N = 6), transitional clinics (N = 2), and community-based harm reduction programs (N = 1), as well as two emerging models. Summary Key components of such models are the provision of (1) medication-assisted treatment for OUD, (2) HIV and HCV treatment, (3) HIV pre-exposure prophylaxis, and (4) behavioral health services. Research is needed to understand differences in effectiveness between co-located and fully integrated care, combat the deleterious racial and ethnic legacies of the “War on Drugs,” and inform the delivery of psychiatric care. Increased access to harm reduction services is crucial

Identification of the As-bearing phases in fresh volcanic Andean ashes

The sources and dynamics of arsenic in fresh volcanic ashes collected during the eruptions of Hudson (1991) and Puyehue (2011) volcanos, have been studied. The chemical and mineralogical compositions of both volcanic ashes were analyzed by ICP/OES, XRD, and SEM-EDS. Batch experiments were conducted to evaluate the kinetics of the arsenic release under variable pH. Results indicate that the release is enhanced under both, acidic and alkaline conditions. Besides, the positive significant linear trend found between Fe and As concentrations in the leachates suggests that arsenopyrite or/and its alteration product scorodite is one important As-bearing phase present in the ash samples. This phase would be the main responsible of the As release under acidic conditions. At higher pH, two other mechanisms are involved: desorption from Fe(hydr)oxide coatings (at neutral to slightly alkaline conditions) and dissolution of both arsenopyrite and volcanic glass at pH higher than 9.Fil: Bia, Gonzalo Luis.Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Ciencias de la Tierra; Argentina.Fil: Bia, Gonzalo Luis. Universidad Nacional de Córdoba; Argentina.Fil: Borgnino, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Ciencias de la Tierra; Argentina.Fil: Borgnino, Laura. Universidad Nacional de Córdoba; Argentina.Fil: Gaiero, Diego M. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Ciencias de la Tierra; Argentina.Fil: Gaiero, Diego M. Universidad Nacional de Córdoba; Argentina.Fil: García, Maria Gabriela. Universidad Nacional de Córdoba; Argentina.Fil: García, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Ciencias de la Tierra; Argentina.Otras Ciencias Química