Using monatomic nitrogen induced by a pulsed arc to remove nitrogen oxides from a gas stream

The effectiveness of monatomic nitrogen, induced by a pulsed electric arc, in reducing nitric oxide (NO) and nitrogen dioxide (NO{sub 2}) was studied. The goal for this research is the reduction of nitrogen oxides (NO{sub x}) from automobile emissions by this alternative technique, which can be cost-effective (to be demonstrated in the near future) and has the potential to reduce NO{sub x} in exhaust containing up to 10% oxygen. The initial tests with 100, 500, and 1,000 ppm NO in pure nitrogen have shown that a greater than 50% reduction of NO/NO{sub x} is readily achievable. Different flow rates of the monatomic nitrogen and the gas stream were tested. The flow rate of the monatomic nitrogen did not have a significant effect on the reduction efficiency, unlike the flow rate of the gas stream. The cross-sectional flow area of the gas stream was varied in order to assess whether the proximity of the gas stream to the arc would affect NO/NO{sub x} reduction. Results of the tests revealed that the smallest cross-sectional area gave the best reduction, but it also had the greatest chance of contacting the arc. The composition of the gas stream was also varied to elucidate the effects of NO{sub 2} and O{sub 2} on the NO/NO{sub x} reduction efficiency. When NO{sub 2} and O{sub 2} are present in the gas stream, both gases lower the reduction efficiency significantly by creating more NO or NO{sub 2}. Experiments are continuing to improve the reduction efficiency. The electrical power, a function of pulse frequency, voltage, and current, was treated as a key parameter in the investigation. The power consumption of the high-voltage pulser apparatus for a 100-kW engine was estimated to be 3 kW

Researching COVID to Enhance Recovery (RECOVER) adult study protocol: Rationale, objectives, and design

Importance SARS-CoV-2 infection can result in ongoing, relapsing, or new symptoms or other health effects after the acute phase of infection; termed post-acute sequelae of SARS-CoV-2 infection (PASC), or long COVID. The characteristics, prevalence, trajectory and mechanisms of PASC are ill-defined. The objectives of the Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC in Adults (RECOVER-Adult) are to: (1) characterize PASC prevalence; (2) characterize the symptoms, organ dysfunction, natural history, and distinct phenotypes of PASC; (3) identify demographic, social and clinical risk factors for PASC onset and recovery; and (4) define the biological mechanisms underlying PASC pathogenesis. Methods RECOVER-Adult is a combined prospective/retrospective cohort currently planned to enroll 14,880 adults aged 18 years. Eligible participants either must meet WHO criteria for suspected, probable, or confirmed infection; or must have evidence of no prior infection. Recruitment occurs at 86 sites in 33 U.S. states, Washington, DC and Puerto Rico, via facility- and community-based outreach. Participants complete quarterly questionnaires about symptoms, social determinants, vaccination status, and interim SARS-CoV-2 infections. In addition, participants contribute biospecimens and undergo physical and laboratory examinations at approximately 0, 90 and 180 days from infection or negative test date, and yearly thereafter. Some participants undergo additional testing based on specific criteria or random sampling. Patient representatives provide input on all study processes. The primary study outcome is onset of PASC, measured by signs and symptoms. A paradigm for identifying PASC cases will be defined and updated using supervised and unsupervised learning approaches with cross-validation. Logistic regression and proportional hazards regression will be conducted to investigate associations between risk factors, onset, and resolution of PASC symptoms. Discussion RECOVER-Adult is the first national, prospective, longitudinal cohort of PASC among US adults. Results of this study are intended to inform public health, spur clinical trials, and expand treatment options. Registration NCT05172024. Copyright: © 2023 Horwitz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]