Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Chemosphere ; 362: 142656, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38908449

RESUMEN

Feedstock characteristics impact biochar physicochemical properties, and reproducible biochar properties are essential for any potential application. However, in most articles, feedstock aspects (i.e., taxonomic name of the species, part of the plant, and phenological phase) are scarcely reported. This research aimed at studying the effect of species and phenological stage of the feedstock on the properties of the derived biochars and, thus, adsorption capacities in water treatment. In this study, we analysed the anatomical characteristics of three different woody bamboo species [Guadua chacoensis (GC), Phyllostachys aurea (PA), and Bambusa tuldoides (BT)] in culms harvested at two different phenological phases (young and mature), and statistically correlated them with the characteristics of the six derived biochars, including their adsorption performance in aqueous media. Sclerenchyma fibres and parenchyma cells diameter and cell-wall width significantly differed among species. Additionally, sclerenchyma fibres and parenchyma cell-wall width as well as sclerenchyma fibre cell diameters are dependent on the phenological phase of the culms. Consequently, differences in biochar characteristics (i.e., yield and average pore diameter) were also observed, leading to differential methylene blue (MB) adsorption capacities between individuals at different phenological phases. MB adsorption capacities were higher for biochar produced from young culms compared to those obtained from matures ones (i.e., GC: 628.66 vs. 507.79; BT: 537.45 vs. 477.53; PA: 477.52 vs. 462.82 mg/g), which had smaller cell wall widths leading to a lower percentage of biochar yield. The feedstock anatomical properties determined biochar characteristics which modulated adsorption capacities.


Asunto(s)
Bambusa , Carbón Orgánico , Azul de Metileno , Carbón Orgánico/química , Azul de Metileno/química , Adsorción , Bambusa/química , Purificación del Agua/métodos , Madera/química
2.
Molecules ; 21(3): 248, 2016 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-26927034

RESUMEN

Oil-in-water nanoemulsions are stable systems with droplet sizes in the 20-200 nm range. The physicochemical properties of these systems may be influenced by the addition of additives. Thus, the influence of ethoxylated (EL) and acetylated lanolin (AL) addition on the droplet size, pH values, electrical conductivity and stability of nanoemulsions was investigated. Then, effect of nano-emulsions additives with EL (NE-EL) or AL (NE-AL) in hydration, oiliness and pH of the skin were evaluated. Nanoemulsion safety was evaluated through the observation of no undesirable effects after skin formulation application. Both additives caused changes in droplet size and electrical conductivity, but not in pH values. Nanoemulsions containing up to 6.0% ethoxylated lanolin and 2.0% acetylated lanolin remained stable after centrifugation tests. Higher concentrations of the additives made the nanoemulsions unstable. Stability tests showed that ethoxylated lanolin produced more stable nanoemulsions then acetylated lanolin and that the major instability phenomenon occurring in these systems is coalescence at elevated temperatures. Nanoemulsion-based lanolin derivatives increased skin hydration and oiliness and did not change cutaneous pH values. These formulations are non-toxic since they did not cause any irritation on the skin surface after nanoemulsion application, showing potential as carriers for pharmaceuticals and cosmetic applications.


Asunto(s)
Cosméticos/química , Lanolina/química , Nanoestructuras/química , Aceites de Plantas/química , Agua/metabolismo , Acetilación , Adulto , Transporte Biológico , Cosméticos/farmacocinética , Estabilidad de Medicamentos , Conductividad Eléctrica , Emulsiones , Femenino , Calor , Humanos , Concentración de Iones de Hidrógeno , Lanolina/farmacocinética , Tamaño de la Partícula , Aceites de Plantas/farmacocinética , Polietilenglicoles/química , Piel/efectos de los fármacos , Absorción Cutánea/fisiología , Viscosidad , Agua/química
3.
J Plant Res ; 127(2): 307-13, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24162620

RESUMEN

Neotropical woody bamboos range from northern Mexico to southern Argentina and Chile. The most interesting aspect of bamboo biology is their flowering habit. The species that are the most intriguing are those that manifest a cyclic pattern of gregarious flowering after long vegetative periods. The flowering cycle has been described in very few species. The goal was to identify mass flowering events of woody bamboo species native to Argentina and neighboring areas, and to estimate the flowering cycle of each species. Sixteen species were surveyed: Chusquea culeou, C. deficiens, C. lorentziana, C. montana, C. quila, C. ramosissima, C. tenella, C. valdiviensis; Colanthelia rhizantha; Guadua chacoensis, G. paraguayana, G. trinii; Merostachys clausenii, M. multiramea, Rhipidocladum neumannii and R. racemiflorum. To reconstruct flowering dates, information from literature and herbarium collections was consulted and more than 990 records were gathered. Flowering cycles were estimated by recording the intervals between reported flowering events. Evidence of regular flowering cycles of ca. 30 years was found for most of the species considered. There is a remarkable concentration of flowering cycles about multiples of 15-16 years. Flowering synchrony among different species of woody bamboos was recorded for the first time in South America.


Asunto(s)
Flores/fisiología , Poaceae/fisiología , Argentina , Especificidad de la Especie , Factores de Tiempo , Madera
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA