Sol-Gel Synthesis and Characterization of the Cu-Mg-O System for Chemical Looping Application

A sol-gel technique was applied to prepare the two-component oxide system Cu-Mg-O, where MgO plays the role of oxide matrix, and CuO is an active chemical looping component. The prepared samples were characterized by scanning electron microscopy, low-temperature nitrogen adsorption, and X-ray diffraction analysis. The reduction behavior of the Cu-Mg-O system was examined in nine consecutive reduction/oxidation cycles. The presence of the MgO matrix was shown to affect the ability of CuO towards reduction and re-oxidation significantly. During the first reduction/oxidation cycle, the main characteristics of the oxide system (particle size, crystallization degree, etc.) undergo noticeable changes. Starting from the third cycle, the system exhibits a stable operation, providing the uptake of similar hydrogen amounts within the same temperature range. Based on the obtained results, the two-component Cu-Mg-O system can be considered as a prospective chemical looping agent.     

Chemical composition,antioxidant activity and antibacterial effect of essential oil of the aerial parts of Salvia sclareoides

ObjectiveTo determine the chemical composition, antioxidant activity and antibacterial properties of essential oils of the aerial parts of Salvia sclareoides (S. sclareoides).MethodsThe essential oil of the areal parts of S. sclareoides was obtained by using hydrodistillation method and the composition of the volatile components analyzed by gas chromatography method coupled with mass spectrometry detector. The antimicrobial capacity of the essential oil of S. sclareoides was investigated by microdilution technique. The antioxidant activities were determined employing inhibition of 2,2-diphenyl-1-picrylhydrazyl hydrate radical method.ResultsMass spectra were searched against mass spectrometry databases and sixty components were recognized. Non-terpenoids (41.6%) and sesquiterpenes (39.7%) were determined as the main components of the essential oil. The main identified components were, linalool (27.6%), trans-caryophyllene (16.6%), beta.-trans-ocimene (11.831%), germacrene-D (10%), bicyclogermacrene (3.3%) and caryophyllene oxide (2.8%). Two monoterpens (13.2%) and three oxygenated sesquiterpenes (5.5%) were also obtained from the essential oil of the S. sclareoidesConclusionsResults indicated that essential oil of S. sclareoides includes rather higher proportions of non-terpenoid and sesquiterpenes compounds with good antioxidant and antibacterial properties.