Spatial mask filtering algorithm for partial discharge pulse extraction of large generators

A spatial mask filter algorithm （SMF） for partial discharge （PD） pulse extraction is proposed in this paper. In this algorithm, firstly, a ＇Teager＇ operator is used to strengthen wavelet coefficient local energy; then direct multiplication of coefficients at two adjacent scales is used to detect singularity points of the signal and to obtain scale based spatial mask filter; finally, an ＇ AND＇ logic operator is used in different filters to obtain the last spatial mask filter. By multiplication of wavelet coefficients with the final mask filter and wavelet reconstruction process, partial discharge pulses are extracted. The results of digital simulation and practical experiment show that this method is superior to traditional wavelet shrinkage method （TWS）. This algorithm not only can increase the signal to noise ratio （SNR）, but also can preserve the encrgy and pulse amplitude.

Design aspect of a novel L-shaped pulsed column for liquid–liquid extraction applications: Energy consumption and the characteristics velocity concept

This article deals with the evaluation of the consumption of energy for a steady state solvent extraction in a novel L-shaped pulsed sieve-plate column, which is highly required for design and optimization of the periodic flow processes for industrial applications. In this regard, a comprehensive evaluation on the energy consumption in case of a pulsed flow for three different chemical systems is conducted and besides the influence of pulsation intensity, the effect of geometrical parameters including the plate spacing and the plate free area is investigated as well. Moreover, the concept of characteristic velocity models at flooding points is evaluated with respect to the variation of pressure drop along the column at different operational conditions.

Recent advances in extraction of antioxidants from plant by-products processing industries

The by-products obtained from plant processing industries are the cheap source of bioactive compounds especially antioxidants.Extraction of bioactive compounds can be obtained by using conventional and non-conventional methods.Extraction efficiency of any conventional method mainly depends on the choice of solvents.The major challenges of conventional extraction are longer extraction time,requirement of costly and high purity solvent,evaporation of the huge amount of solvent,low extraction selectivity,and thermal decomposition of thermolabile compounds.To overcome these limitations of conventional extraction methods,new and promising extraction techniques are introduced.These techniques are referred as non-conventional extraction techniques.Therefore,in this review,some of the most promising techniques such as ultrasoundassisted extraction,pulsed electric field extraction,enzyme-assisted extraction,microwave-assisted extraction,pressurized liquid extraction,supercritical fluid extraction,pressurized low-polarity water extraction,and molecular distillation were discussed.The process systems along with industrial applications for non-conventional method of antioxidants extraction were discussed,and the comparative efficacies of different extraction methods were highlighted.Replacing conventional technologies by non-conventional ones for the extraction of valuable compounds from plant by-products processing industries has several advantages,which includes reduction of the processing time,energy consumption,and the uses of harmful and expensive solvents and increase in the extraction yields.Incorporation and development of hybrid methods should be investigated,while considering plant material characteristics and choice of compounds in future.Proper choice of standard methods also influences the measurement of extraction efficiency.The increasing economic significance of bioactive compounds and commodities rich in these bioactive compounds may lead to find out more sophisticated extraction methods in future.

Extracting cavity and pulse phases from limited data for coherent pulse stacking

Coherent pulse stacking（CPS） is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy and high average power. A Z-domain model targeting the pulsed laser is assembled to describe the optical interference process. An algorithm, extracting the cavity phase and pulse phases from limited data, where only the pulse intensity is available, is developed to diagnose optical cavity resonators. We also implement the algorithm on the cascaded system of multiple optical cavities,achieving phase errors less than 1.0°（root mean square）, which could ensure the stability of CPS.