SARS-CoV-2 RNA Persistence in Municipal Wastewater Treatment Systems Proves Wastewater Surveillance Is an Effective Tool for Monitoring COVID-19 Community Health Burdens

Wastewater surveillance of SARS-CoV-2 is used worldwide to track COVID-19 infection trends. However, there is no standard method for SARS-CoV-2 measurement from wastewater, and uncertainties of pre-analytical influences from the wastewater collection system persist. This study builds upon the growing body of knowledge surrounding wastewater surveillance and aims to understand how wastewater measurements relate to other public health metrics, explain the influence of wastewater conveyance systems, and improve SARS-CoV-2 detection and quantification from wastewater. Our laboratory has been part of the ongoing Wisconsin SARS-CoV-2 wastewater surveillance program since August 2020, analyzing almost 4,000 samples to date. Through various experiments, our findings demonstrated that monitoring variants in wastewater using RT-ddPCR can outperform clinical sequencing. Temperature was the only parameter that significantly influenced SARS-CoV-2 decay in the wastewater matrix. Travel time, flow rate, BOD, and TSS, did not significantly influence SARS-CoV-2 decay or detection. Additionally, extracting RNA from primary settled solids improved detection sensitivity

Visualizing DIII-D Tokarnak Magnetic Field Lines

We demonstrate the use of a combination of perceptually effective techniques for visualizing magnetic field data from the DIII-D Tokamak. These techniques can be implemented to run very efficiently on machines with hardware support for OpenGL. Interactive speeds facilitate clear communication of magnetic field structure, enhancing fusion scientists' understanding of their data, and thereby accelerating their research

Wakefield Computations for the CLIC PETS using the Parallel Finite Element Time-Domain Code T3P

In recent years, SLAC's Advanced Computations Department (ACD) has developed the high-performance parallel 3D electromagnetic time-domain code, T3P, for simulations of wakefields and transients in complex accelerator structures. T3P is based on advanced higher-order Finite Element methods on unstructured grids with quadratic surface approximation. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with unprecedented accuracy, aiding the design of the next generation of accelerator facilities. Applications to the Compact Linear Collider (CLIC) Power Extraction and Transfer Structure (PETS) are presented

Simulating Dark Current in NLC Structures

Dark current generation and capture are of great importance in high gradient accelerating structure R&D especially for the NLC which aims to operate at 65 MV/m with specific limits on dark current and RF breakdown rates. Although considerable effort has been devoted to building and testing various types of structures to meet these requirements, few theoretical studies have been done to understand these effects in actual structures. This paper focuses on the simulation of dark current in a NLC test structure for which experimental data are available. The parallel time-domain field solver Tau3P and the parallel particle tracking code Track3P are used together to simulate, for the first time, a dark current pulse to compare with the data measured downstream. Results from SLAC X-band 30-cell constant impedance structure for RF drive pulses with different rise times are presented and discussed