A pseudo anapole based electromagnetic cloaking scheme using Split Ring Resonators

This paper proposes the first experimental demonstration of a pseudo-anapole-based cylindrical electromagnetic cloaking scheme. The pseudo-anapole state is excited by arranging split-ring resonators around a cylindrical metallic target. We used the multipole scattering theory to identify the actual reason behind the cloaking operation. Pseudo anapole condition is characterized by the scattering minima from toroidal and electric dipole moments, and hence the metallic target is undetectable from backscattering measurements. The results are verified using full-wave simulation software and subsequently validated with backscattering measurements inside an anechoic chamber.

Numerical Simulation of Laser-Induced Bubble and Metal-Free Water Cannon

Laser propulsion is expected to be the next-generation propulsion mechanism. In particular, metal-free water cannon realizes propulsion without a metallic target. In this study, we develop a numerical simulation code using the C-CUP (CIP and Combined, Unified Procedure) method to simulate a laser-induced bubble and a metal-free water cannon. We successfully reproduced the qualitative behavior of spouting water in a three-dimensional space when the metal-free water cannon is irradiated by laser. Furthermore, the calculated results for the time development of displacement of the metal-free water cannon agree qualitatively with the experimental results. We simulate the behavior of the laser-induced bubble and discovered that the bubble inhales the water once spouted out, and the target moves backward owing to the pressure difference generated by the bubble expansion as well as collapsing and inhaling actions. Furthermore, the laser-induced bubble repeats the expansion and collapse, and the target moves forward while it oscillates.

Highly effective silver oxides: influence of oxygen concentration on antibacterial activity against clinical strains of Staphylococcus aureus

Aim of study. Comparative analysis of antibacterial activity of silver oxides (Ag0,2O, Ag1 O, Ag2 O) in relation to clinical strains of Staphylococcus aureus obtained from patients with orthopaedic infection. Material and methods. Films of silver oxides were coated on paper surface in vacuum via the method of ion-plasma arc sputtering of the metallic target. Isolation of S.aureus was performed via standard manual methods from January to June 2021, identification was carried out via the MALDI-TOF-MS method. Sensitivity to antibiotics was evaluated according to EUCAST (2021, v.11.0) requirements. Antibacterial activity of the silver oxide samples obtained against 130 clinical strains of S.aureus was analysed in liquid nutrient broth with subsequent measurement of optical density. Results. Over 90% of the clinical strains of S.aureus isolated from patients with orthopaedic infection were sensitive to the silver oxides obtained. The amount of oxygen in the compound exerted almost no influence on the sensitivity to the oxides: even a minimum ratio between silver and oxygen provided a pronounced antibacterial effect. Additionally, the sensitivity to silver oxides did not depend on the MRSA resistance phenotype and the compounds were effective against XDR strains of S.aureus in 96.7% of the cases. Conclusion. All tested samples of silver oxides (Ag0,2O, Ag1 O, Ag2O) were characterised by pronounced antibacterial activity against S. aureus. The data obtained point to prospects in application of silver oxides for prevention and treatment of orthopaedic infection induced by Staphylococcus aureus without regard for the sensitivity phenotype of the pathogen.

Lifetimes of core-excited states in semi-magic $$^{95}\mathrm {Rh}$$

Lifetimes of negative-parity states have been determined in the neutron deficient semi-magic (N = 50) nucleus $$^{95}\mathrm {Rh}$$ 95 Rh . The fusion-evaporation reaction $$^{58}Ni(^{40}Ca, 3p)$$ 58 N i ( 40 C a , 3 p ) was used to populate high-spin states in $$^{95}\mathrm {Rh}$$ 95 Rh at the Grand Accélérateur National d’Ions Lourds (GANIL) accelerator facility. The results were obtained using the Doppler Shift Attenuation Method (DSAM) based on the Doppler broadened line shapes produced during the slowing down process of the residual nuclei in a thick $$6\;\mathrm {mg/cm}^2$$ 6 mg / cm 2 metallic target. B(M1) and B(E2) reduced transition strengths are compared with predictions from large-scale shell-model calculations.