Evaluación de la eficiencia de un humedal artificial de flujo vertical con Chrysopogon zizanioides para el tratamiento de aguas grises en la urbanización El Cóndor-Callao, 2021

La presente investigación tuvo como objetivo evaluar la eficiencia de un humedal artificial de flujo vertical con Chrysopogon zizanioides para el tratamiento de aguas grises en una vivienda ubicada en la urbanización “El Condor”, Callao 2021. La investigación fue de tipo aplicada, de diseño experimental y nivel explicativo. Se analizaron tres muestras en siete tiempos diferentes, la cual para dos muestras se realizaron tres repeticiones cada una de ellas. Para el tratamiento de aguas grises se realizó mediante un humedal artificial de flujo de vertical (HAFV) con medidas de 2 metros de largo, 1,6 metros de ancho y 50 centímetros de profundidad o altura en un tiempo total de 13 días, con la especie vegetal Chrysopogon zizanioides también llamada comúnmente Vetiver. Los resultados en el pre-tratamiento fueron de 820 mg/L, 167 UNT, 367,5 mg/L, 1138 mg/L y 83,290 mg/L, en el posttratamiento los resultados promedios fueron de 9,7 mg/L, 52 UNT, 58,3 mg/L, 187,7 mg/L y 0,025 mg/L; obteniendo los siguientes porcentajes de remoción 99,39%, 99,40%, 98,80%, 97,81% y 99,97% para SST, Turbidez, DBO5, DQO y Detergentes respectivamente. Finalmente, se concluyó que la utilización de esta tecnología es un método eficiente para remover los contaminantes establecidos presentes en las aguas grises, ya que al compararlo con los Estándares de calidad ambiental de agua para riego de vegetales (categoría 3: D1), los valores están por debajo de los establecidos

Nano- and microstructural evolution of alginate beads in simulated gastrointestinal fluids. Impact of M/G ratio, molecular weight and pH

peer-reviewedAlginate microcapsules were prepared using three different alginate grades and incubated under simulated digestion conditions. Their micro- and nanostructural changes were studied using microscopy, laser diffraction and small angle X-ray scattering. Both the molecular weight and M/G ratio affected the size and nanostructural features of the capsules, but the changes in gastrointestinal conditions were mainly determined by the latter. All microcapsules swelled slightly in simulated gastric fluid (pH = 3) and swelled further in simulated intestinal fluid (pH = 7), particularly those with high mannuronic acid (M) contents. While high guluronic acid (G) beads maintained the nanostructural features characteristic of alginate gels (junction zones) in both media, these were rapidly disrupted in the M-rich capsules. Decreasing the pH of the gastric phase from 3 to 2 had dramatic structural impacts, resulting in a greater integrity of the microcapsules, thus highlighting the importance of the selected digestion protocol for rational microcapsule design

Exchange-only virial relation from the adiabatic connection

The exchange-only virial relation due to Levy and Perdew is revisited. Invoking the adiabatic connection, we introduce the exchange energy in terms of the right-derivative of the universal density functional w.r.t. the coupling strength $\lambda$ at $\lambda=0$. This agrees with the Levy-Perdew definition of the exchange energy as a high-density limit of the full exchange-correlation energy. By relying on $v$-representability for a fixed density at varying coupling strength, we prove an exchange-only virial relation without an explicit local-exchange potential. Instead, the relation is in terms of a limit ($\lambda \to 0+$) involving the exchange-correlation potential $v_\mathrm{xc}^\lambda$, which exists by assumption of $v$-representability. On the other hand, a local-exchange potential $v_\mathrm{x}$ is not warranted to exist as such a limit

Behavioral responses of wild rodents to owl calls in an austral temperate forest

Ecologically based rodent management strategies are arising as a sustainable approach to rodent control, allowing us to preserve biodiversity while safeguarding human economic activities. Despite predator signals being known to generally repel rodents, few field-based studies have compared the behavioral effects of several predators on different prey species, especially in Neotropical ecosystems. Here, we used camera traps to study the behavior of rodent species native to the Chilean temperate forest (Abrothrix spp., long-tailed pygmy rice rat Oligoryzomys longicaudatus) and an introduced rodent (black rat Rattus rattus). Using playbacks of raptor calls, we experimentally exposed rodents to three predation risk treatments: austral pygmy owl calls (Glaucidium nana), rufous-legged owl calls (Strix rufipes) and a control treatment (absence of owl calls). We evaluated the effects of the treatments on the time allocated to three behaviors: feeding time, locomotor activity and vigilance. Moonlight and vegetation cover were also considered in the analyses, as they can modify perceived predation risk. Results showed that predator calls and environmental factors modified prey behavior depending not only on the predator species, but also on the rodent species. Consequently, owl playbacks could be regarded as a promising rodent control tool, knowing that future studies would be critical to deeply understand differences between species in order to select the most effective predator cues

Variabilidad de las mediciones antropométricas obtenidas por protocolo ISAK y bioimpedancia en usuarios de un gimnasio, Trujillo 2023

El presente estudio tuvo como finalidad analizar la variabilidad de las mediciones antropométricas obtenidas a través de dos métodos distintos, el protocolo ISAK y la bioimpedancia, en usuarios de un gimnasio en Trujillo durante 2023. Tuvo un diseño no experimental de corte transversal de tipo aplicado; la muestra estuvo constituida por 58 usuarios, tanto hombres como mujeres, mayores de 18 años. Para evaluar la composición corporal, se aplicaron dos técnicas de medición: la antropometría basada en el protocolo ISAK nivel I y la bioimpedancia utilizando un dispositivo OMRON HBF-514C. Se usó la prueba de Chi cuadrado para identificar diferencias significativas entre los métodos y el análisis de T-Student para verificar la homogeneidad en las varianzas de las variables. Los resultados revelaron una asociación significativa (P<0,00) y una correlación positiva moderada (r = 0,639) entre las mediciones de porcentaje de grasa por ISAK y bioimpedancia, así como una asociación altamente significativa (P<0,00) y una correlación positiva fuerte (r = 0,721) para el porcentaje de músculo. Existe una relación altamente significativa y positiva entre ambas metodologías de medición, lo que sugiere que estos métodos son consistentes y confiables para evaluar la composición corporal en esta población de usuarios de gimnasio

Plantas aquáticas secas : uma alternativa moderna para remoção de metais pesados de efluentes industriais

O presente trabalho mostra o potencial de aplicação da biomassa seca e morta de plantas aquáticas na remoção de metais pesados de efluentes industriais. Dados referentes as caracteristicas dos tecidos vegetais das espécies Potamogeton lucens. Salvinia sp. e Eichornia crassipes e como ocorre a interação com os metais são apresentados. Adicionalmente, os resultados obtidos no tratamento de um efluente de galvanoplastia em uma coluna de percolação em escala piloto preenchida com uma mistura das biomassas das plantas P. lucens e Salvínia sp. são reportados. A eficiência do processo foi medida em relação a remoção dos metais cobre. zinco. niquel e ferro. Os resultados mostram que a alternativa estudada é eficiente na remoção de metais presentes de forma residual em efluentes da indústria metal-mecânica.The present work shows the potential use of the non-living biomass,of aquatic plants for the removal of heavy metal ions from Waste waters. It is reported the main characteristics of the plant tissues of the species Poramogeron lucens, Salvinia sp·, and Eichhornia crassipes and the mechanis of metal binding. Additiolly, the results obtained in the treatememt ofm electroplanting wastewater in a packed bed column filled with a mixture of P.Lucens ,and Salvinia sp· biomasses are showen. The process efficiency was evaluated in terms of copper, zinc, nickel and iron removed. The results show that the process studied is efficient for the removal of residual concentration of heavy metal present in waste waters from metalfinishing industries