Blast response of full-size concrete walls with chemically reactive enamel （CRE）-coated steel reinforcement

In this study, two full-size concrete wails were tested and analyzed to demonstrate the effectiveness of a chemically reactive enamel （CRE） coating in improving their mechanical behavior under blast loading： one with CRE-coated rebar and the other with uncoated rebar. Each wall was subjected in sequence to four explosive loads with equivalent 2, 4, 6-trinitrotoluene （TNT） charge weights of 1.82, 4.54, 13.6, and 20.4 kg. A finite element model of each wall under a close-in blast load was developed and validated with pressure and strain measurements, and used to predict rebar stresses and concrete surface sWain distributions of the wall. The test results and visual inspections consistently indicated that, compared with the barrier wall with uncoated reinforcement, the wall with CRE-coated rebar has fewer concrete cracks on the front and back faces, more effective stress transfers from concrete to steel rebar, and stronger connections with its concrete base. The concrete surface strain distributions predicted by the model under various loading conditions are in good agreement with the crack patterns observed during the tests.

Using posterior part of the deltoid muscle as receptor and quality control with intra-operative electrophysiological examination in targeted muscle reinnervation for high-level upper extremity amputees

To the Editor:Targeted muscle reinnervation(TMR)is a surgical technique of multiple nerve transfers,providing a potential of improved intuitive prosthetic control via surface electromyography(sEMG)in the high-level upper extremity amputees.[1]However,there is a risk that some of the reinnervations might be unsuccessful,especially for the ulnar nerve.[2]Both the quality control of nerve stumps and the receptor are important factors for the surgery.Assessing the nerve stumps during the surgery and finding more muscles as receptor might address the problem.Biceps,triceps,and brachialis muscles were mostly chosen as receptors for reinnervation in the trans-humeral amputees.Pectoralis major and pectoralis minor were mostly chosen as receptors for reinnervation in the shoulder disarticulation patients.