Silver-based Microbial Check Valve for Spacecraft Potable Water Systems

As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team decided to design a controlled release system capable of meeting the constraints listed in the problem statement. By using a membrane similar to those within dialysis devices a system was designed to deliver silver ions to a stream of water that requires arguably no power and is exceptionally lightweight. While the silver delivery system fulfilled the constraints of the WERC problem statement, our team also examined the use of resins like those contained in the current Microbial Check Valve (MCV). Resin substitutes capable of selective silver sorption are recommended as replacements for those within the current MCV to prevent backwards microbial diffusion through the system. Multiple designs will be presented in this paper. First, our membrane-controlled release silver delivery system (SDS) is presented to specifically address the WERC Task 1 deliverables. Second, a proposed upgrade to the ISS water system is described that replaces the ion exchange resin beds with silver-selective media prevent microbial contamination of water in the potable water system of the spacecraft. Given the extreme lightweight nature of the SDS, nil power requirement, and minor modification to the existing system, Hogs In Space has delivered a highly effective method to deliver and control silver based on the WERC Task 1 requirements

Nonlinear optimization of beam lines

The current final focus systems of linear colliders have been designed based on the local compensation scheme proposed by P. Raimondi and A. Seryi [1]. However, there exist remaining aberrations that deteriorate the performance of the system. This paper develops a general algorithm for the optimization of beam lines based on the computation of the high orders of the transfer map using MAD-X [2] and PTC [3]. The algorithm is applied to the CLIC [4] Beam Delivery System (BDS)

Preliminary Development of The Dialysis-Membrane-based Passive Biocide Delivery System for Spacecraft Water Recovery Units

The purpose of this investigation is to explore the capabilities of a dialysis-membrane-based system for the in-line dosing of silver ions to treated water in spacecraft water recovery units. The spacecraft environmental control and life support system community (ECLSS) are interested in adopting silver ions as a biocide in future spacecraft water recovery processes since silver ions are effective biocide at concentrations that humans can safely consume. The system has been designed following the configuration of the Water Processor Assembly (WPA) aboard the International Space Station. In this configuration, silver ions have to be added at the last step in the WPA to inhibit the growth of microorganisms in the product water. The dialysis-membrane-based system has to supply silver ions into the potable water at concentrations ranging from 200 to 400 parts per billion during the entire water processing time. The silver ion delivery system has been prototyped by repurposing dialysis membranes used for the separation/purification of low molecular weight solutes. Consequently, the low molecular weight cutoff of the dialysis membrane controls the silver ion release from a concentrated silver ion reservoir and does not require any power. Both computational and experimental studies were conducted to examine the performance of the silver ion delivery and the feasibility of integrating this technology in future spacecraft water recovery units. The preliminary results from this investigation show that the dialysis-membrane-based passive biocide delivery system can supply sufficient silver ions to a stream of deionized water. Nevertheless, the outflow might require dilution, and the membrane may need to undergo preconditioning for optimal performance, especially for reuse

“Arkansas Global Changemakers and the effect of collaborative and disruptive strategies”

In this essay, we consider the ways in which disruptive strategies align with collaborative strategies to produce innovations aimed at ameliorating global challenges in the twenty-first century. Specifically, we consider how they work through our current initiative, Arkansas Global Changemakers, which creates new international partnerships at the local level in order to challenge long-standing obstacles to global social change

“Arkansas Global Changemakers and the effect of collaborative and disruptive strategies”

In this essay, we consider the ways in which disruptive strategies align with collaborative strategies to produce innovations aimed at ameliorating global challenges in the twenty-first century. Specifically, we consider how they work through our current initiative, Arkansas Global Changemakers, which creates new international partnerships at the local level in order to challenge long-standing obstacles to global social change

The Disproportionate Impact of COVID-19 on Older Latino Mortality: The Rapidly Diminishing Latino Paradox

Objectives: This brief report aims to highlight stark mortality disparities among older Latinos that result from the novel coronavirus disease (COVID-19) pandemic. Methods: We use recent data from the Centers for Disease Control and Prevention to compute age-specific death rates (ASDRs) for three causes of death: deaths from COVID-19, residual deaths, and total deaths for four age-groups (55-64, 65-74, 75-84, and 85 and older) to assess the impact of COVID-19 on older Latino mortality relative to non-Latino Whites and non-Latino Blacks and also in comparison to residual deaths. Additionally, we obtain ASDRs for all causes of deaths from 1999 to 2018 to provide a pre-pandemic context and assess the extent to which the consistently observed mortality advantage of Latinos persists during the pandemic. Results: Consistent with previous research, our findings show that Latinos have lower ASDRs for non-COVID-19 causes of death across all age groups compared to non-Latino Whites. However, our findings indicate that Latinos have significantly higher ASDRs for COVID-19 deaths than non-Latino Whites. Furthermore, although the Latino advantage for total deaths persists during the pandemic, it has diminished significantly compared to the 1999-2018 period. Discussion: Our findings indicate that as a result of the pandemic, the time-tested Latino paradox has rapidly diminished due to higher COVID-19 mortality among older Latino adults compared to non-Latino Whites. Future research should continue to monitor the impact of COVID-19 to assess the disparate impact of the pandemic on older Black, Latino and non-Latino White adults as additional data become available

Federal Regulatory Reform: An Overview

This report provides an overview federal regulatory reform