Low-frequency noise pollution in substations has a significant impact on the physical and mental health of workers. Reduction low-frequency is an urgent problem to solve for researchers. In this paper, different structures Al 2 O 3 -polyurethane composites micro-perforated plate were constructed, effects cavity depth, perforated plate, foam position sound absorption properties comprehensively i...

When vermiform appendix is found in the inguinal hernial sac, the condition is called Amyand's hernia (AH). Appendix in hernial sac can be normal, inflamed or perforated. It can present as complicated hernia or acute scrotum. We present a case of Amyand's hernia in a 25-day-old male who presented with an obstructed hernia having perforated appendix in the hernial sac.

We successfully rescued a patient whose coronary artery perforated following implantation of a drug-eluting stent (DES), by deploying a stent-graft in symptomatic myocardial bridging. Our case demonstrated that coronary perforation could be handled without difficulty when perforated myocardial bridging is confined to the interventricular groove.

We discuss several models for a flash-heat experiment in homogeneous isotropic media. We use these to investigate the use of homogenization techniques in approximating models for interrogation via flash-heating in porous materials. We represent porous materials as both randomly perforated domains and periodically perforated domains.