RESUMO
Renewable energy powered membrane systems that are directly-connected must take account of both the inherent fluctuations and the intermittency of the energy resource. In order to determine the effect of intermittent operation, a membrane system was tested with variables of (i) amplitude from 60 to 300 W and (ii) length of time with no power from 0.5 to 3 min. This was performed over one hour periods with six on/off cycles to simulate the system operating under intermittent operation for short periods of time when directly-connected to a small wind turbine. The setup used a Filmtec BW30-4040 brackish water reverse osmosis membrane with feed waters of 2,750 mg/L and 5,500 mg/L NaCl. The results showed that the membrane system produced potable water under the majority of intermittency experiments performed. There was a relatively large increase in the average salt concentration of the permeate, especially when the system was off for shorter periods of time (0.5-1 min). Longer periods of no power (1-3 min) did not have as significant an effect on the average water quality. This is important when the need for energy buffering or short term storage is considered for these systems as it shows the potential for improving the overall flux and water quality using temporary energy storage.
Assuntos
Membranas Artificiais , Salinidade , Sais/isolamento & purificação , Purificação da Água/métodos , Vento , Eletricidade , Fatores de Tempo , Eliminação de Resíduos LíquidosRESUMO
From cell cultures of Taxus chinensis var. mairei, yunnanxane [2 alpha, 5 alpha, 10-beta triacetoxy-14 beta-(2'-methyl-3'-hydroxyl)-butyryloxy-4(20),11-taxadiene, [1], and four new homologous esters, 2 alpha, 5 alpha, 10 beta, 14 beta- tetra-acetoxy-4(20),11-taxadiene [2], 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-propionyloxy-4(20),11-taxadiene [3], 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-isobutyryloxy-4(20),11- taxadiene [4], and 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-(2'-methyl)-butyryloxy-4(20),11- taxadiene [5] have been isolated. Their structures were determined by spectroscopic methods.
Assuntos
Antineoplásicos Fitogênicos/química , Diterpenos/química , Medicamentos de Ervas Chinesas/química , Antineoplásicos Fitogênicos/biossíntese , Células Cultivadas , Ésteres , Espectroscopia de Ressonância Magnética , Caules de Planta/citologia , Caules de Planta/metabolismoRESUMO
Four new taxoids were isolated from cell cultures of Taxus baccata. Their structures were elucidated by spectroscopic analyses. Two were the aglycones corresponding to previously isolated 7-O-xylosides of taxol C [1] and 10-deacetyltaxol C [2]. The third [3] had an N-methylated side-chain, while the fourth, named taxcultine [4], contained an n-propyl group on the side-chain. All four compounds actively promoted tubulin assembly. Taxol C [1] showed potent and selective cytotoxicity in the NCI human cell line screen.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Paclitaxel/análogos & derivados , Paclitaxel/isolamento & purificação , Plantas Medicinais/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , California , Células Cultivadas , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Peso Molecular , Paclitaxel/química , Paclitaxel/farmacologia , Tubulina (Proteína)/biossínteseRESUMO
A method has been developed for rapidly determining the amounts of alpha-carotene, beta-carotene, and cryptoxanthin in orange juice. The procedure includes extraction, saponification, and high-speed liquid chromatography. Limits of detection for the 3 carotenoids are 0.04, 0.02, and 0.04 mug/ml, respectively.
