Search

In this article, the effects of microwave frequency (2450 MHz and 5800 MHz) and gas humidity (1%, 2%, 3%, 4%, 6% and 8%) on in vitro blood coagulation with cold atmospheric pressure plasma (CAPP) were investigated. The generation of reactive oxygen species (ROS, OH, O) was measured by optical emission spectra. The exposure temperature on blood droplets under treatment was below 55 °C in all cases, to avoid the thermal effect of plasma on the blood clotting. Investigations showed that, with the increase of frequency, the doses of ROS increased, the blood sample presented a more serious collapse and its surface became drier. The humidity of ionized gas can also accelerate the generation of ROS and the process of blood clotting. Our results propose a method to accelerate in vitro blood coagulation in CAPP by adjusting microwave frequency and gas humidity, and suggest a clinical benefit for plasma treatment as a coagulation device in surgery.

For the nonlinearly phenomena on the dielectric properties of dimethyl sulfoxide (DMSO)–ethanol mixtures under a low intensity microwave field, we propose a conjecture that there exist some abnormal molecular clusters. To interpret the mechanism of abnormal phenomena and confirm our conjecture about the existence of abnormal molecular clusters, an in-depth investigation about the structure evolutions of (DMSO)m(C2H5OH)n (m = 0–4; n = 0–4; m + n ≤ 4) molecular clusters induced by external electric fields has been given by using density functional theory. The results show that there exist some binary molecular clusters with large cluster radii in mixtures, and some of them are unstable under exposure of electric fields. It implies that the existence of certain abnormal molecular clusters in DMSO-ethanol mixtures results in their abnormality of dielectric properties.

A printed slot antenna fed by a microstrip line with a diamond-shaped tuning stub for bandwidth enhancement is proposed and experimentally validated. Impedance bandwidth, radiation pattern, and gain characteristics of the proposed antenna are investigated. The simulated results show that the impedance matching of the proposed rotated slot antenna is greatly afiected by the dimension of the slot and by the size and the position of the diamond-shaped tuning stub. The experimental results demonstrate that this antenna exhibits an ultra-wide impedance bandwidth, which is over 123% for jS11j • i10dB ranging from 2.80 to 11.81GHz. Moreover, a stable and omnidirectional radiation pattern is observed within the operating bandwidth.

By coupling Maxwell's equations, the Fourier equation of heat conduction and chemical reaction together, the FDTD method was used to simulate a simplified chemical reaction model under microwave irradiation. The chemical reaction process, temperature distribution and electromagnetic characters of the system can be obtained. This is useful for microwave chemistry applications.