Assessment of environmental factors influencing SARS-CoV-2 in Vietnam's surface water across two years of clinical data.

Wastewater-based epidemiology (WBE) is an effective, non-invasive method for monitoring the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by tracking viral prevalence in water. This study aimed to investigate the presence of SARS-CoV-2 in surface water in Vietnam over two years. One-step quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were employed to quantify SARS-CoV-2 and its variant-specific mutation sites (G339D/E484A) and pepper mild mottle virus (PMMoV) from a total of 315 samples (105 samples per site) to compare with reported Coronavirus disease 2019 (COVID-19) cases and environmental factors.

3D models for hydrothermal copper ore bodies at Sin Quyen deposit, North Vietnam: A case report for ore reserves and prediction of hidden mineral resource potential.

The complex iron oxide copper and gold (IOCG) Sin Quyen deposit in northern Vietnam is known as hydrothermal veins and multi-stages of mineralization. Thus, it is complicated to make a probabilistic 3D geometric model using traditional methods and to predict the hidden mineral potential. In this study, computer modeling with nearly 8000 archival data was recorded from 146 boreholes within the study area, and the chemical analysis was done on 40 samples.

A compact co-aperture dual-sense circularly polarized antenna for simultaneous transmit and receive systems.

This paper proposes a compact design of dual-sense circularly polarized (CP) antenna for simultaneous transmit (Tx) and receive (Rx) communication systems. The primary radiating aperture of the proposed antenna is a 2 × 2 unit-cell metasurface (MS). The MS is excited by the asymmetric patch in the center, which acts as the CP source of the whole antenna structure.

Metasurface-based dual-sense circularly polarized antenna for MIMO/full-duplex applications.

This paper introduces a two-element antenna array with dual-sense circular polarization, wideband operation, and high isolation characteristics. The antenna consists of two conventional truncated corner patches and an extra layer of metasurface (MS) located above the radiating patches. The overall dimensions of the proposed antenna are 0.

Multibeam Characteristics of a Negative Refractive Index Shaped Lens.

Narrow beam width, higher gain and multibeam characteristics are demanded in 5G technology. Array antennas that are utilized in the existing mobile base stations have many drawbacks when operating at upper 5G frequency bands. For example, due to the high frequency operation, the antenna elements become smaller and thus, in order to provide higher gain, more antenna elements and arrays are required, which will cause the feeding network design to be more complex.