Failure characteristics and the damage evolution of a composite bearing structure in pillar-side cemented paste backfilling

A backfilling body-coal pillar-backfilling body(BPB)structure formed by pillar-side cemented paste backfilling can bear overburden stress and ensure safe mining.However,the failure response of BPB composite samples must be investigated.This paper examines the deformation characteristics and damage evolution of six types of BPB composite samples using a digital speckle correlation method under uniaxial compression conditions.A new damage evolution equation was established on the basis of the input strain energy and dissipated strain energy at the peak stress.The prevention and control mechanisms of the backfilling body on the coal pillar instability were discussed.The results show that the deformation localization and macroscopic cracks of the BPB composite samples first appeared at the coal-backfilling interface,and then expanded to the backfilling elements,ultimately appearing in the coal elements.The elastic strain energy in the BPB composite samples reached a maximum at the peak stress,whereas the dissipated energy continued to accumulate and increase.The damage evolution curve and equation agree well with the test results,providing further understanding of instability prevention and the control mechanisms of the BPB composite samples.The restraining effect on the coal pillar was gradually reduced with decreasing backfilling body element's volume ratio,and the BPB composite structure became more vulnerable to failure.This research is expected to guide the design,stability monitoring,instability prevention,and control of BPB structures in pillar-side cemented paste backfilling mining.

Electrochemical biomaterials for self-powered implantable“tissue batteries”:A tutorial review

Currently,due to improvements in living standards,people are paying more attention to all-around disease prevention and health care.Self-powered implantable“tissue batteries”integrated with electrochemical materials are essential for disease prevention,diagnosis,treatment,postoperative therapy,and healthcare applications.We propose and define new concepts of“tissue batteries”-self-powered tissue batteries(SPTBs)-are flexible self-powered implantable systems or platforms based on electroactive biomaterials,acting at the interface of biological tissue.Based on the electrical phenomenon of living organisms in life activities,there has been an increased attention to SPTBs for tissue repair promotion.SPTBs take advantages of both the preeminent biocompatibility of biomaterials and the promotion of time-honored electrical stimulation therapy for tissue recovery,which are very promising for human illness treatment.However,studies on clinical applications of SPTBs are impeded by a lack of comprehensive cognitive assessment of SPTBs.Herein,SPTBs for life and health applications are comprehensively reviewed.First,electrochemical materials and their across-the-board applications for several types of SPTBs are introduced and compared with regard to disease prevention,diagnosis,precision therapy,and personalized health monitoring.Then,the potential mechanisms for SPTBs for tissue repair promotion are discussed.Finally,the prospective challenges are summarized and recommendations for future research are provided.This review elucidates on the significance and versatility of SPTBs for various medical applications.