Performance evaluation of virus concentration methods for implementing SARS-CoV-2 Wastewater-based epidemiology emphasizing quick data turnaround.

Wastewater based epidemiology (WBE) has drawn significant attention as an early warning tool to detect and predict the trajectory of COVID-19 cases in a community, in conjunction with public health data. This means of monitoring for outbreaks has been used at municipal wastewater treatment centers to analyze COVID-19 trends in entire communities, as well as by universities and other community living environments to monitor COVID-19 spread in buildings. Sample concentration is crucial, especially when viral abundance in raw wastewater is below the threshold of detection by RT-qPCR analysis. We evaluated the performance of a rapid ultrafiltration-based virus concentration method using InnovaPrep Cp Select pipette tips and compared this to the established electronegative membrane filtration (EMF) method. We evaluated the sensitivity of SARS-CoV-2 quantification, surrogate virus recovery rate, and sample processing time. Results suggest that the Cp Select concentrator is more efficient at concentrating SARS-CoV-2 from wastewater compared to the EMF method. 30% of samples that tested negative when concentrated with the EMF method produced a positive signal with the Cp Select protocol. Increased recovery of the surrogate virus control using the Cp Select confirms this observation. We optimized the Cp Select protocol by adding AVL lysis buffer and sonication, to increase the recovery of virus. Sonication increased BCoV recovery by 19%, which seems to compensate for viral loss during centrifugation. Filtration time decreases by approximately 30% when using the Cp Select protocol, making this an optimal choice for building surveillance applications where a quick turnaround time is necessary.

Initial designing a dual-band antenna baced on end-fed dipole-like radiators for digital antenna arrays

The paper deals with the designing of the initial arrangement for dual-band antennas comprising two parallel dipole-like radiators as the drivers for the mentioned antenna. The excitation of the drivers is provided by the source of the induced electromotive forces (EMF), whose outputs are attached to the remote terminals of the radiators. The paper also provides the key electrodynamic characteristics of the structure under research for the following procedure of multi-parametric nonlinear optimization. In addition, on the basis of the induced EMF method, has been obtained the expressions for the far-field zone (Fraunhofer zone) characteristics with taking into account the parasitic currents on the radiating bodies of the dipole, which allows more accurate design of the initial topology of the antenna.

Effect of magnesium and calcium on oxygen activity in model nickel melts at PAr = 0.1 MPa and analysis of nonmetallic inclusions

The EMF method was used to study the oxygen activity in nickel melts during the deoxidation of Mg/Ca (up to 0.2 wt.%) in the atmosphere of ultrapure Ar. The logarithmic dependences were expressed in the change a[O] from the concentrations of deoxidizers. A significant increase in the deoxidation capacity of Mg and Ca was shown in comparison with Al at a content of 0.05 wt.% of the deoxidizers in the metal. The morphology and composition of nonmetallic inclusions after deoxidation were studied and complex configurations of nonmetallic inclusions from 2 to 100 microns located along the grain boundaries were shown.

Thermodynamic investigations of the erbium tellurides by EMF method

The work presents the results of a thermodynamic study of the Er-Te system by the method of electromotive forces (EMF) in the temperature range of 300-450 K. From the EMF measurements of the concentration cells relative to the Er and ErTe electrodes, the partial thermodynamic functions of ErTe and Er in the alloys are determined, based on which the standard thermodynamic formation functions and the standard entropies of the intermediate compounds ErTe3, Er2Te3, and ErTe are calculated. A comparative analysis of the obtained data with the literature is carried out.