Search results for "Microwave method"
showing 2 items of 2 documents
The Essential Oil Composition ofEryngium foetidumL. in South Vietnam Extracted by Hydrodistillation under Conventional Heating and Microwave Irradiat…
2008
Abstract Essential oils of Eryngium foetidum L. (Apiaceae) in the South Vietnam isolated by hydrodistillation under conventional heating or microwave irradiation showed somewhat similar in chemical compositions. The microwave method gave a higher extraction yield in a much shorter time frame than the conventional heating protocol. Noticeably, the oil obtained from the microwave method showed a stronger antimicrobial activity than the other. Among all parts of the plant, inflorescence contained the highest oil content, and three-month old plant material was found richest in oil content as well. Physical, chemical and antibacterial properties of the oil products isolated from both methods wer…
A combined optical-microwave method to retrieve soil moisture over vegetated areas
2011
A simple approach for correcting for the effect of vegetation in the estimation of the surface soil moisture (wS) from L-band passive microwave observations is presented in this study. The approach is based on semi-empirical relationships between soil moisture and the polarized reflectivity including the effect of the vegetation optical depth which is parameterized as a function of the normalized vegetation difference index (NDVI). The method was tested against in situ measurements collected over a grass site from 2004 to 2007 (SMOSREX experiment). Two polarizations (horizontal/vertical) and five incidence angles (20◦, 30◦, 40◦, 50◦, and 60◦) were considered in the analysis. The best wS est…