Sonolytic Decomposition of Aqueous Bioxalate in the Presence of Ozone

Ultrasonic irradiation in the presence of ozone is demonstrated to be effective for the rapid oxidation of oxalic acid, bioxalate, and oxalate (H_(2)C_(2)O_(4)/HC_(2)O_(4)−/C_(2)O_(4)^2−) in aqueous solution to CO_2 and H_(2)O. The degradation rate of bioxalate exposed to “sonozone” (i.e., simultaneous ultrasonication and ozonolysis) was found to be 16-times faster than predicted by the linear addition of ozonolysis and ultrasonic irradiation rates. The hydroxyl radical (•OH) is the only oxy-radical produced that can oxidize oxalate on a relevant time-scale. Thus, plausible •OH production mechanisms are evaluated to explain the observed kinetic synergism of ultrasonication and ozonolysis toward bioxalate decomposition. •OH production via decomposition of O_3 in the cavitating bubble vapor and via the reaction of O_3 and H_(2)O_2 are considered, but kinetic estimations and experimental evidence indicate neither to be a sufficient source of •OH. A free-radical chain mechanism is proposed in which the HC_(2)O_(4)− + •OH reaction functions as a primary propagation step, while the termination occurs through the O_3 + CO_(2)•− reaction via an O-atom transfer mechanism. Kinetic simulations confirm that ozone reacts efficiently with the superoxide (O_(2)•−) ion that is produced by the reaction of O_2 and CO_(2)•− to form •OH radical, and that the reaction of O_3 + CO_(2)•− must be chain terminating. Oxalate is also readily oxidized by “peroxone” treatment (i.e., H_(2)O_2 and O_3). However, the addition of H_(2)O_2 during the course of the sonolytic ozonation of oxalic acid does not appear to increase the observed degradation rate and decreases rates at millimolar levels

Analise semiotica de um ava (ambiente virtual de ensino aprendizagem) : características cts através da escada semotica de Stamper

Este artigo demonstra um estudo e aplicação da análise semiótica, para a avaliação de interfaces de ambientes virtuais de ensino-aprendizagem (AVA), de acordo com a escada semiótica de Stamper. Com base nas características CTS (Ciência,Tecnologia e Sociedade) encontrada nas camadas “degrais” da escada. Em específico, usamos a metodologia para qualidade de interfaces definida por Schimiguel, que instancia critérios de qualidade para cada uma das camadas da escada semiótica de Stamper. Com base nos resultados dessa investigação foi possível sugerir algumas recomendações nas seis camadas analisadas, sinalizando ainda para cada uma dessas recomendações um enfoque CTS, uma descrição que tem como propósito facilitar a implementação e otimização de AVAS

Electrospray Mass Spectrometric Detection of Products and Short-Lived Intermediates in Aqueous Aerosol Microdroplets Exposed to a Reactive Gas

The intermediates ISO_3^- (m/z = 207) and IS2O3- (m/z = 239) generated in aqueous (NaI/Na_2S2O_3) microdroplets traversing dilute O_3 gas plumes are detected via online electrospray mass spectrometry within ∼1 ms, and their stabilities gauged by collisionally induced dissociation. The simultaneous detection of anionic reactants and the S_2O_6^(2-), HSO_4^-, IO_3^-, and I_3^- products as a function of experimental conditions provides evidence of genuinely interfacial reaction kinetics. Although O_3(aq) reacts about 3 times faster with I- than with S_2O_3^(2-) in bulk solution, only S_2O_3^(2-) is significantly depleted in the interfacial layers of [I^-]/[S_2O_3^(2-)] = 10 microdroplets below [O_3(g)] ∼ 50 ppm

Analise semiotica de um ava (ambiente virtual de ensino aprendizagem) : características cts através da escada semotica de Stamper

Este artigo demonstra um estudo e aplicação da análise semiótica, para a avaliação de interfaces de ambientes virtuais de ensino-aprendizagem (AVA), de acordo com a escada semiótica de Stamper. Com base nas características CTS (Ciência,Tecnologia e Sociedade) encontrada nas camadas "degrais" da escada. Em específico, usamos a metodologia para qualidade de interfaces definida por Schimiguel, que instancia critérios de qualidade para cada uma das camadas da escada semiótica de Stamper. Com base nos resultados dessa investigação foi possível sugerir algumas recomendações nas seis camadas analisadas, sinalizando ainda para cada uma dessas recomendações um enfoque CTS, uma descrição que tem como propósito facilitar a implementação e otimização de AVAS

Orange essential oil inclusion compleX with B-cyclodextrin.

Cyclodextrins due to its structure composed of internal cavities hydrophobic and essentially hydrophilic extremities has the ability to form inclusion complexes with various substances. Thus, the objective of this study was to produce an inclusion complex of ?-CD with Valência orange essential oil (OEO), using the precipitation method and characterizing it through the scanning electron microscopy analysis (SEM) and differential scanning calorimetry (DSC), and to characterize the orange essential oil by gas chromatography-mass spectrometry (CG-EM) The d-limonene (95.56%) was the major component, followed by ?-Myrcene (2.35%), octanal (0.55%), ?-pinene (0.54%), ?-linalol (0.45%), cyclohexene (0.29%) and finally, decanal (0.26%)of OEO. The results show that waspossible to produce aninclusion omplexbetween orange essential oil and ?-CD. The inclusion complex showed greater interaction with the orange essential oil when compared to the physical mixture

Produção de suínos em sistema de ciclo completo: custos e receitas da utilização dos dejetos.

Este trabalho teve como objetivo estimar os custos de distribuição dos dejetos de uma criação de suínos com 42 matrizes em sistema de ciclo completo e as receitas obtidas do seu uso como substituto dos fertilizante químicos. Foram definidas as quantidades de dejetos produzidas, a área de aplicação e os custos de transporte. Posteriormente estimadas as receitas que os dejetos gerariam substituindo fertilizantes químicos como a uréia, o super triplo e o cloreto de potássio.bitstream/item/111047/1/Cot474.pd

Fowl typhoid in Argentine Republic

Luego de un brote de Tifosis en un criadero con 100.000 aves en producción a jaula (50% Leghorn y 50% AA-Harco), un 8,38% de positivos (Harco) a la prueba de aglutinación rápida, son trasladados a tinglado individual y alojados igualmente en jaula. Luego de 50 coprocultivos negativos, los animales son reanalizados con la misma prueba 30~60-90 y 120 días después, comprobándose que dichos positivos disminuían del 100 al 32%, no habiéndose constatado en todo ese tiempo, diferencia con su lote similar. Transcurrido ese período, 30 animales son descargados con cepa virulenta, comprobándose que sólo el 1% muere por Tifosis, frente al lote testigo donde los insucesos son del 50% Estos hechos son analizados estadísticamente entendiendo que la prueba de aglutinación no debe aplicarse con el mismo criterio que para la pullorosis ya que, según los resultados, muestra un valor muy relativo. Se efectúan paralelamente, consideraciones inmunológicas sobre la posible importancia de la lg A en los mecanismos de defensa de las aves.After a Typhoid outbreak in a farm with 100.000 birds in production in cages (50% Leghorn and 50% AA-Harco), 8,38% of positive reactors to the quick agglutination test (Harco) were transferred to an individual house also in cages. After 50 negative coprocultures, the birds are again assayed by the same test 30-60-90 and 120 days after, finding that said positives decreased from 100 to 32%. No difference was noted during that period with the similar lot. After that time, 30 birds are challenged with a virulent strain and only 1% die of Typhoid; as compared with the control group where mortality was 50%. These facts are statistically analyzed finding that the agglutination test should not be used with the same criteria as for pullorum, since, according to the findings, its value is quite relative. At the same time, immunological considerations were effected on the possible importance of Ig G and Ig A in the defense mechanisms of birds against infections caused by enterobacteria.Facultad de Ciencias Veterinaria

Resonance triplet dynamics in the quenched unitary Bose gas

The quenched unitary Bose gas is a paradigmatic example of a strongly interacting out-of-equilibrium quantum system, whose dynamics become difficult to describe theoretically due to the growth of non-Gaussian quantum correlations. We develop a conserving many-body theory capable of capturing these effects, allowing us to model the post-quench dynamics in previously inaccessible time regimes. By comparing our results directly to experiment, we answer long-standing fundamental questions regarding the heating and population dynamics in the gas, specifically highlighting the dominance of strong lossless correlations rather than incoherent atomic losses. Our general framework, which reframes the dynamics of unitary quantum systems in terms of explicit connections to microscopic physics, can be broadly applied to any quantum system containing strong few-body correlations.Comment: 7 pages, 4 figure

Fowl typhoid in Argentine Republic

Luego de un brote de Tifosis en un criadero con 100.000 aves en producción a jaula (50% Leghorn y 50% AA-Harco), un 8,38% de positivos (Harco) a la prueba de aglutinación rápida, son trasladados a tinglado individual y alojados igualmente en jaula. Luego de 50 coprocultivos negativos, los animales son reanalizados con la misma prueba 30~60-90 y 120 días después, comprobándose que dichos positivos disminuían del 100 al 32%, no habiéndose constatado en todo ese tiempo, diferencia con su lote similar. Transcurrido ese período, 30 animales son descargados con cepa virulenta, comprobándose que sólo el 1% muere por Tifosis, frente al lote testigo donde los insucesos son del 50% Estos hechos son analizados estadísticamente entendiendo que la prueba de aglutinación no debe aplicarse con el mismo criterio que para la pullorosis ya que, según los resultados, muestra un valor muy relativo. Se efectúan paralelamente, consideraciones inmunológicas sobre la posible importancia de la lg A en los mecanismos de defensa de las aves.After a Typhoid outbreak in a farm with 100.000 birds in production in cages (50% Leghorn and 50% AA-Harco), 8,38% of positive reactors to the quick agglutination test (Harco) were transferred to an individual house also in cages. After 50 negative coprocultures, the birds are again assayed by the same test 30-60-90 and 120 days after, finding that said positives decreased from 100 to 32%. No difference was noted during that period with the similar lot. After that time, 30 birds are challenged with a virulent strain and only 1% die of Typhoid; as compared with the control group where mortality was 50%. These facts are statistically analyzed finding that the agglutination test should not be used with the same criteria as for pullorum, since, according to the findings, its value is quite relative. At the same time, immunological considerations were effected on the possible importance of Ig G and Ig A in the defense mechanisms of birds against infections caused by enterobacteria.Facultad de Ciencias Veterinaria