The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil...The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil was extracted from fresh Rosa x damciscena Mill. petals by four methods, hydrodistillation, steam distillation, organic solvent extraction and ultrasounds followed by microwave hydrodistillation. The chemical composition of the extracts was analysed by GC-MS, and the antioxidant capacity by DPPH. It was found that both chemical composition and the antioxidant activity of the extracts depend on the extraction method. Overall it was found that microwaves coupled with ultrasonic treatment can be used effectively for the intensification of the extraction of monoterpenes and sesquiterpenes--fragrance bearing molecules--and equally, for increased antioxidant activity while using about 4 time shorter extraction time. The scale-up of the method was also evaluated. The results obtained in this research support the possible use of the US/MW method for the extraction of rose essential oil for the pharmaceutical and fragrance industry.展开更多
This paper introduces the design and development of intelligent ultrasonic ＂pig＂ used for seabed pipeline inspection. The data acquisition system （DAS） and the signal processing method are presented. The DAS was d...This paper introduces the design and development of intelligent ultrasonic ＂pig＂ used for seabed pipeline inspection. The data acquisition system （DAS） and the signal processing method are presented. The DAS was designed using a muhi-DSP based structure. The signal processing method adopted a well-enhanced split-spectrum processing （SSP） based on weighting algorithm according to statistical times, which was the statistical distribution of the discrete signals selected by the minimization algorithm. Furthermore, the data compressing method was discussed. It assures the mass data to be processed and compressed in real-time. The effectiveness of the method was proved by laboratory experiments. The research provides an excellent base for further development of the ultrasonic pig.展开更多
文摘The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil was extracted from fresh Rosa x damciscena Mill. petals by four methods, hydrodistillation, steam distillation, organic solvent extraction and ultrasounds followed by microwave hydrodistillation. The chemical composition of the extracts was analysed by GC-MS, and the antioxidant capacity by DPPH. It was found that both chemical composition and the antioxidant activity of the extracts depend on the extraction method. Overall it was found that microwaves coupled with ultrasonic treatment can be used effectively for the intensification of the extraction of monoterpenes and sesquiterpenes--fragrance bearing molecules--and equally, for increased antioxidant activity while using about 4 time shorter extraction time. The scale-up of the method was also evaluated. The results obtained in this research support the possible use of the US/MW method for the extraction of rose essential oil for the pharmaceutical and fragrance industry.
基金Supported by the High Technology Research and Development Program of China (Grant No2001AA602021)
文摘This paper introduces the design and development of intelligent ultrasonic ＂pig＂ used for seabed pipeline inspection. The data acquisition system （DAS） and the signal processing method are presented. The DAS was designed using a muhi-DSP based structure. The signal processing method adopted a well-enhanced split-spectrum processing （SSP） based on weighting algorithm according to statistical times, which was the statistical distribution of the discrete signals selected by the minimization algorithm. Furthermore, the data compressing method was discussed. It assures the mass data to be processed and compressed in real-time. The effectiveness of the method was proved by laboratory experiments. The research provides an excellent base for further development of the ultrasonic pig.
