Design and tolerance analysis of a router with an amplified resonator and Bragg gratings

A novel ring resonator configuration with Bragg gratings is presented. The stability of this configuration is studied by a z-transform technique. A router design with a FWHM of 17 MHz, a -40-dB rejection ratio, and a 15-dB gain at the output port is reported. The influence of temperature and of fabrication tolerance on parameters of this router configuration implemented with fiber technology is reviewed. Deviations in design specification owing to parameter variations are studied and compensated for with a gain control of 2.4% in a specific designA novel ring resonator configuration with Bragg gratings is presented. The stability of this configuration is studied by a z-transform technique. A router design with a FWHM of 17 MHz, a -40-dB rejection ratio, and a 15-dB gain at the output port is reported. The influence of temperature and of fabrication tolerance on parameters of this router configuration implemented with fiber technology is reviewed. Deviations in design specification owing to parameter variations are studied and compensated for with a gain control of 2.4% in a specific desig

Novel tuneable filter based on MZ and an amplified ring resonator for OFDM networks

A novel reconfigurable fibre based tuneable filter is proposed. The module relies on a cascaded connection of Mach-Zehnders and an amplified fibre ring resonator. MHz range adjustable FHWM bandwidths and high crosstalk are achieved.A novel reconfigurable fibre based tuneable filter is proposed. The module relies on a cascaded connection of Mach-Zehnders and an amplified fibre ring resonator. MHz range adjustable FHWM bandwidths and high crosstalk are achieved

Modeling Short-Term Soil−Water Distribution of Aromatic Amines

The applicability of a distributed parameter model for describing the distribution of aniline and α-naphthylamine between soil and aqueous phases at short contact times was assessed. Mass action equations considered in the distributed parameter model were (a) acid dissociation of the protonated organic amine (BH+); (b) sorption of the neutral species (B) to soil organic carbon through the partition coefficient Koc; and (c) ion exchange of the protonated organic amine and inorganic divalent cations (Ca2+ + Mg2+ = D2+). The last reaction was expressed mathematically as separated association reactions for each cation to unoccupied cation exchange sites, with constants KBH and KD. A Gaussian distribution on log KBH values with mode μ and standard deviation σ was employed. The overall model was expressed as a system of two nonlinear equations with two unknown values (BH+ and D2+). The model was evaluated with aniline and α-naphthylamine isotherms measured on three Indiana soils ranging in pH (4.5−7.0) and added calcium concentration (0.5−50 mM) after a 24 h contact period. The parameters Koc, μ, and σ for each amine were obtained by minimizing the sum of squared residuals between predicted and measured aqueous-phase organic amine concentrations (i.e., [B]aq + [BH+]aq) for all soil, pH, and CaCl2 conditions, simultaneously. Calculated isotherms were compared against those calculated with the general form of the speciation model in which a singular value of KBH was employed. The distributed parameter form of the model resulted in nonlinear calculated isotherms in general agreement with the curvature of α-naphthylamine measured isotherms. Skewed distributions on log KBH were evaluated also.The applicability of a distributed parameter model for describing the distribution of aniline and α-naphthylamine between soil and aqueous phases at short contact times was assessed. Mass action equations considered in the distributed parameter model were (a) acid dissociation of the protonated organic amine (BH+); (b) sorption of the neutral species (B) to soil organic carbon through the partition coefficient Koc; and (c) ion exchange of the protonated organic amine and inorganic divalent cations (Ca2+ + Mg2+ = D2+). The last reaction was expressed mathematically as separated association reactions for each cation to unoccupied cation exchange sites, with constants KBH and KD. A Gaussian distribution on log KBH values with mode μ and standard deviation σ was employed. The overall model was expressed as a system of two nonlinear equations with two unknown values (BH+ and D2+). The model was evaluated with aniline and α-naphthylamine isotherms measured on three Indiana soils ranging in pH (4.5−7.0) and added calcium concentration (0.5−50 mM) after a 24 h contact period. The parameters Koc, μ, and σ for each amine were obtained by minimizing the sum of squared residuals between predicted and measured aqueous-phase organic amine concentrations (i.e., [B]aq + [BH+]aq) for all soil, pH, and CaCl2 conditions, simultaneously. Calculated isotherms were compared against those calculated with the general form of the speciation model in which a singular value of KBH was employed. The distributed parameter form of the model resulted in nonlinear calculated isotherms in general agreement with the curvature of α-naphthylamine measured isotherms. Skewed distributions on log KBH were evaluated also

Enabling NFC technology to public services

Ambient Intelligent are usually emerged in contexts like health, education, business and so on. However there are not many researches focusing on social aspects as public administrations. In these kinds of contexts, some problems are continuously in our minds. Especially these that people waste time on clues or solving dubs about the required documents. In this work we present a proposal through the adaptability of the Near Field Communication technology (NFC). With it, some tags and readers can interact with the mobile phones, running different applications according to the places, contexts and users' requirements.Ambient Intelligent are usually emerged in contexts like health, education, business and so on. However there are not many researches focusing on social aspects as public administrations. In these kinds of contexts, some problems are continuously in our minds. Especially these that people waste time on clues or solving dubs about the required documents. In this work we present a proposal through the adaptability of the Near Field Communication technology (NFC). With it, some tags and readers can interact with the mobile phones, running different applications according to the places, contexts and users' requirements

Induced Desorption of DDT, DDD, and DDE from a Contaminated Sediment

Release profiles of p,p′-DDT, p,p′-DDD, and p,p′-DDE from sediment collected from Indian Creek, Alabama, were measured with a gas purge-induced desorption technique and compared to a model developed in this work. DDT entered this sediment via effluent discharged upstream from the collection site from 1947 to 1970 by a DDT manufacturing facility. The purge technique used vessels constructed with 70–100 μm fritted glass bottoms, through which air enters, distributing gas bubbles evenly to a sediment-water suspension. Purging compound from the water phase with the gas bubbles induced desorption of compound from the sediment particles. The purged chemicals were captured on tenax traps. Purge experiments were performed with sediment masses ranging from 0.37 to 3.7 g in 200 mL water at an air flow rate of 1 L/min. The total percentage removal of each compound after 46 days averaged 22, 58, and 75% for DDT, DDD, and DDE, respectively, indicating the extreme resistance of DDT to desorption from this sediment. The time to reach 25% removal was approximately 50 days for DDT and 4 days for DDD. Results are compared to a simple Fickian diffusion model in which diffusion is assumed to occur in one direction from a fixed depth to a plane surface. The concentration at the exposed surface is assumed to be in equilibrium with the aqueous concentration, which in turn is depleted by transfer to the gas phase through first-order decay. Simulations indicate that DDD transfer across the liquid-gas interface is limiting at high sediment concentrations.Release profiles of p,p′-DDT, p,p′-DDD, and p,p′-DDE from sediment collected from Indian Creek, Alabama, were measured with a gas purge-induced desorption technique and compared to a model developed in this work. DDT entered this sediment via effluent discharged upstream from the collection site from 1947 to 1970 by a DDT manufacturing facility. The purge technique used vessels constructed with 70–100 μm fritted glass bottoms, through which air enters, distributing gas bubbles evenly to a sediment-water suspension. Purging compound from the water phase with the gas bubbles induced desorption of compound from the sediment particles. The purged chemicals were captured on tenax traps. Purge experiments were performed with sediment masses ranging from 0.37 to 3.7 g in 200 mL water at an air flow rate of 1 L/min. The total percentage removal of each compound after 46 days averaged 22, 58, and 75% for DDT, DDD, and DDE, respectively, indicating the extreme resistance of DDT to desorption from this sediment. The time to reach 25% removal was approximately 50 days for DDT and 4 days for DDD. Results are compared to a simple Fickian diffusion model in which diffusion is assumed to occur in one direction from a fixed depth to a plane surface. The concentration at the exposed surface is assumed to be in equilibrium with the aqueous concentration, which in turn is depleted by transfer to the gas phase through first-order decay. Simulations indicate that DDD transfer across the liquid-gas interface is limiting at high sediment concentrations

Recruiting a PRA Team That Works

In 1949 the world bank sent 14 international advisers to Colombia. These expert in foreign exchange, transportation, industry, agriculture, and others represented the first mission of its kind to attack "underdevelopment" with a comprenhensive program calling for intervention in all social and economic aspects of importance (Escobar 1995).In 1949 the world bank sent 14 international advisers to Colombia. These expert in foreign exchange, transportation, industry, agriculture, and others represented the first mission of its kind to attack "underdevelopment" with a comprenhensive program calling for intervention in all social and economic aspects of importance (Escobar 1995)

Reporte bibliométrico sobre publicaciones panameñas relacionadas al COVID-19 en SCOPUS

Se realizó una búsqueda en la base de datos de Scopus el 4 de mayo de 2021 con los siguientes criterios. Términos de Búsqueda: sars-cov-2, coronavirus, covid-19. Filtros: País (Panamá), Años (2019,2020 ,2021). y se hizo un análisis de estos datos por número de publicaciones, tipos de publicación, tipos de acceso abierto, publicaciones más citadas, áreas de investigación, palabras claves, colaboración y organizaciones.Se realizó una búsqueda en la base de datos de Scopus el 4 de mayo de 2021 con los siguientes criterios. Términos de Búsqueda: sars-cov-2, coronavirus, covid-19. Filtros: País (Panamá), Años (2019,2020 ,2021). y se hizo un análisis de estos datos por número de publicaciones, tipos de publicación, tipos de acceso abierto, publicaciones más citadas, áreas de investigación, palabras claves, colaboración y organizaciones