Scavenging Microwave Wireless Power:A Unified Model,Rectenna Design Automation,and Cutting-Edge Techniques

While sufficient review articles exist on inductive short-range wireless power transfer(WPT),long-haul microwave WPT(MWPT)for solar power satellites,and ambient microwave wireless energy harvesting(MWEH)in urban areas,few studies focus on the fundamental modeling and related design automation of receiver systems.This article reviews the development of MWPT and MWEH receivers,with a focus on rectenna design automation.A novel rectifier model capable of accurately modeling the rectification process under both high and low input power is presented.The model reveals the theoretical boundary of radio frequency-to-direct current(dc)power conversion efficiency and,most importantly,enables an automated system design.The automated rectenna design flow is sequential,with the minimal engagement of iterative optimization.It covers the design automation of every module(i.e.,rectifiers,matching circuits,antennae,and dc–dc converters).Scaling-up of the technique to large rectenna arrays is also possible,where the challenges in array partitioning and power combining are briefly discussed.In addition,several cutting-edge rectenna techniques for MWPT and MWEH are reviewed,including the dynamic range extension technique,the harmonics-based retro-directive technique,and the simultaneous wireless information and power transfer technique,which can be good complements to the presented automated design methodology.

Techniques for postmortem tenderisation in meat processing:effectiveness,application and possible mechanisms

Developing efficient and promising tenderising techniques for postmortem meat is a heavily researched topic among meat scientists as consumers are willing to pay more for guaranteed tender meat.However,emerging tenderising techniques are not broadly used in the meat industry and,to some degree,are controversial due to lack of theoretical support.Thus,understanding the mechanisms involved in postmortem tenderisation is essential.This article first provides an overview of the relationship of ageing tenderisation and calpain system,as well as proteomics applied to identify protein biomarkers characterizing tenderness.In general,the ageing tenderisation is mediated by multiple biochemical activities,and it can exhibit better palatability and commercial benefit by combining other interventions.The calpain system plays a key role in ageing tenderisation functions by rupturing myofibrils and regulating proteolysis,glycolysis,apoptosis and metabolic modification.Additionally,tenderising techniques from different aspects including exogenous enzymes,chemistry,physics and the combined methods are discussed in depth.Particularly,innovation of home cooking could be recommended to prepare relatively tender meat due to its convenience and ease of operation by consumers.Furthermore,the combined interventions provide better performance in controlled tenderness.Finally,future trends in developing new tenderising techniques,and applied consideration in the meat processing industry are proposed in order to improve meat quality with higher economical value.