We optimize the performance of an elastic actuator consisting of an active core in a host which performs mechanical work on a load. The system, initially with localized elastic energy in the active component, relaxes and distributes energy to the rest of the system. Using the linearized Mooney-Rivlin hyperelastic model in a cylindrical geometry and assuming viscous relaxation, we show that the value of Young's modulus of the impedance matching host which maximizes the energy transfer from the active component to the load is the geometric mean of Young's moduli of the active component and the elastic load. This is similar to the classic results for impedance matching for maximizing the transmittance of light propagating through dielectric media.
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http://dx.doi.org/10.1039/d1sm00132a | DOI Listing |
Sci Rep
December 2024
Department of Physics, Faculty of Science, Razi University, Kermanshah, Iran.
Novel functional materials possessing the capability to attenuate electromagnetic energy are being increasingly incorporated into home decor as concerns over excessive electromagnetic radiation pollution continue to grow. The properties of magnetism and dielectricity in the flexible peanut shell/CoFeO/reduced graphene oxide/polyvinyl alcohol (PS/CF/(RGO)/PVA) nanocomposites can be finely tuned by adjusting the amount of RGO in the mixture. An examination of the composite's absorption capabilities revealed a direct link between higher RGO content and enhanced absorption.
View Article and Find Full Text PDFDiseases
November 2024
Sports Medicine Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy.
. Childhood brain tumor survivors (CCSs) are at high risk of developing metabolic syndrome (MetS) and sarcopenia. To date, a tool able to predict any body composition changes or detect them early and increased adiposity (and, therefore, increased likelihood of MetS onset) is still lacking in this population.
View Article and Find Full Text PDFAging Clin Exp Res
December 2024
Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea.
Objective: Metabolic syndrome (MetS) and sarcopenia together pose significant health risks, increasing frailty, falls, and fractures in older adults. This study compared muscle mass measurements obtained using two different dual-energy X-ray absorptiometry (DXA) machines and bioelectrical impedance analysis (BIA), and evaluated the accuracy of these measurements in these older adults.
Methods: In this prospective multicenter cohort study, patients aged ≥ 65 years with MetS had their muscle mass assessed using both BIA and DXA.
Nanomicro Lett
December 2024
School of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.
As modern communication and detection technologies advance at a swift pace, multifunctional electromagnetic interference (EMI) shielding materials with active/positive infrared stealth, hydrophobicity, and electric-thermal conversion ability have received extensive attention. Meeting the aforesaid requirements simultaneously remains a huge challenge. In this research, the melamine foam (MF)/polypyrrole (PPy) nanowire arrays (MF@PPy) were fabricated via one-step electrochemical polymerization.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
College of Bioresources Chemical & Materials Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, China.
Achieving high shielding effectiveness in electromagnetic shielding materials relies heavily on high conductivity, yet simultaneously enhancing the absorption loss remains a persistent challenge. Consequently, the study successfully creates efficient electromagnetic shielding composite films with a unique grape-like bunch structure of hollow nanosilver (HCAF) through layer-by-layer assembly. The utilization of poly(dopamine) (PDA) to anchor nanosilver granules (AgNPs) onto cellulose nanofibers (CNF) results in the formation of CNF@PDA@AgNPs.
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