Final report for DOE Grant No. DE-FG02-07ER64404 - Field Investigations of Microbially Facilitated Calcite Precipitation for Immobilization of Strontium-90 and Other Trace Metals in the Subsurface

Subsurface radionuclide and metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOEâÃÂÃÂs greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent ions, such as the short-lived radionuclide 90Sr, is co-precipitation in calcite. We have previously found that that nutrient addition can stimulate microbial ureolytic activity that this activity accelerates calcite precipitation and co-precipitation of Sr, and that higher calcite precipitation rates can result in increased Sr partitioning. We have conducted integrated field, laboratory, and computational research to evaluate the relationships between ureolysis and calcite precipitation rates and trace metal partitioning under environmentally relevant conditions, and investigated the coupling between flow/flux manipulations and precipitate distribution. A field experimental campaign conducted at the Integrated Field Research Challenge (IFRC) site located at Rifle, CO was based on a continuous recirculation design; water extracted from a down-gradient well was amended with urea and molasses (a carbon and electron donor) and re-injected into an up-gradient well. The goal of the recirculation design and simultaneous injection of urea and molasses was to uniformly accelerate the hydrolysis of urea and calcite precipitation over the entire inter-wellbore zone. The urea-molasses recirculation phase lasted, with brief interruptions for geophysical surveys, for 12 days followed by long-term monitoring which continued for 13 months. Following the recirculation phase we found persistent increases in urease activity (as determined from 14C labeled laboratory urea hydrolysis rates) in the upper portion of the inter-wellbore zone. We also observed an initial increase (approximately 2 weeks) in urea concentration associated with injection activities followed by decreasing urea concentration and associated increases in ammonium and dissolved inorganic carbon (DIC) following the termination of injection. Based on the loss of urea and the appearance of ammonium, a first order rate constant for urea hydrolysis of 0.18 day-1 rate with an associate Rf for ammonium of 11 were estimated. This rate constant is approximately 6 times higher than estimated for previous field experiments conducted in eastern Idaho. Additionally, DIC carbon isotope ratios were measured for the groundwater. Injected urea had a ÃÂô13C of 40.7ÃÂñ0.4 âÃÂð compared to background groundwater DIC of ÃÂô13C of -16.6ÃÂñ0.2âÃÂð. Observed decreases in groundwater DIC ÃÂô13C of up to -19.8âÃÂð followed temporal trends similar to those observed for ammonium and suggest that both the increase in ammonium and the sift in ÃÂô13C are the result of urea hydrolysis. Although direct observation of calcite precipitation was not possible because of the high pre-existing calcite content in the site sediments, an observed ÃÂô13C decrease for solid carbonates from sediment samples collect following urea injection (compared to pre-injection values) is likely the result of the incorporation of inorganic carbon derived from urea hydrolysis into newly formed solid carbonates

Fabrication of periodic microstructures on flexible polyimide membranes

Periodic metallic microstructures were fabricated on polyimide membranes. Techniques were developed to maintain flatness of the membrane during processing while still allowing for flexibility in the final structure. For proper functionality of the structures, it was necessary to first fabricate a continuous metallic film and a continuous dielectric layer on top of the flexible substrate, which underlaid the periodic microstructure. Flexibility of the overall structure was maintained by using a polymer as the dielectric layer, which was constrained to have high optical transmission over the infrared wavelength range of 6-14 mu m. Three candidate polymers were evaluated, and their measured optical properties are presented. Benzocyclobutene was found to be the best choice for this application. The final structure fully populated a 10 cm (4 in.) diameter flexible membrane with microstructures of excellent uniformity. (C) 2007 American Vacuum Society

Organisational participation and women - an attitude problem?

Employee participation is a dynamic and contested area of organisational behaviour, attracting continuing academic, practitioner and policy interest and debate. This chapter focuses on organisational participation and women

A systematic review of the effectiveness and cost-effectiveness of peer education and peer support in prisons.

BACKGROUND: Prisoners experience significantly worse health than the general population. This review examines the effectiveness and cost-effectiveness of peer interventions in prison settings. METHODS: A mixed methods systematic review of effectiveness and cost-effectiveness studies, including qualitative and quantitative synthesis was conducted. In addition to grey literature identified and searches of websites, nineteen electronic databases were searched from 1985 to 2012. Study selection criteria were: Population: Prisoners resident in adult prisons and children resident in Young Offender Institutions (YOIs). INTERVENTION: Peer-based interventions Comparators: Review questions 3 and 4 compared peer and professionally led approaches. OUTCOMES: Prisoner health or determinants of health; organisational/ process outcomes; views of prison populations. STUDY DESIGNS: Quantitative, qualitative and mixed method evaluations. RESULTS: Fifty-seven studies were included in the effectiveness review and one study in the cost-effectiveness review; most were of poor methodological quality. Evidence suggested that peer education interventions are effective at reducing risky behaviours, and that peer support services are acceptable within the prison environment and have a positive effect on recipients, practically or emotionally. Consistent evidence from many, predominantly qualitative, studies, suggested that being a peer deliverer was associated with positive effects. There was little evidence on cost-effectiveness of peer-based interventions. CONCLUSIONS: There is consistent evidence from a large number of studies that being a peer worker is associated with positive health; peer support services are also an acceptable source of help within the prison environment and can have a positive effect on recipients. Research into cost-effectiveness is sparse. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ref: CRD42012002349

Detectors for the James Webb Space Telescope Near-Infrared Spectrograph I: Readout Mode, Noise Model, and Calibration Considerations

We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec's) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some non-ideal behaviors that have been observed in engineering grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is: (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that large-amplitude RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps.Comment: 55 pages, 10 figure

Formation and Degradation of Beta-casomorphins in Dairy Processing

Milk proteins including casein are sources of peptides with bioactivity. One of these peptides is beta-casomorphin (BCM) which belongs to a group of opioid peptides formed from b-casein variants. Beta-casomorphin 7 (BCM7) has been demonstrated to be enzymatically released from the A1 or B b-casein variant. Epidemiological evidence suggests the peptide BCM 7 is a risk factor for development of human diseases, including increased risk of type 1 diabetes and cardiovascular diseases but this has not been thoroughly substantiated by research studies. High performance liquid chromatography coupled to UV-Vis and mass spectrometry detection as well as enzyme–linked immunosorbent assay (ELISA) has been used to analyze BCMs in dairy products. BCMs have been detected in raw cow’s milk and human milk and a variety of commercial cheeses, but their presence has yet to be confirmed in commercial yoghurts. The finding that BCMs are present in cheese suggests they could also form in yoghurt, but be degraded during yoghurt processing. Whether BCMs do form in yoghurt and the amount of BCM forming or degrading at different processing steps needs further investigation and possibly will depend on the heat treatment and fermentation process used, but it remains an intriguing unknown

Total parenteral nutrition associated cholestasis: A predisposing factor for sepsis in surgical neonates?

Of 496 neonates and infants less than 1 year of age admitted to the paediatric surgical intensive care unit (PSICU) over a 5 year period (1983-1987), 94 required total parenteral nutrition (TPN) for more than 14 consecutive days, generally due to congenital anomalies of the digestive tract. Cholestasis occurred in 15 of them and 12 of these patients developed sepsis. In contrast, of the 79 patients on TPN that remained free from cholestasis, only 23 developed sepsis. The mortality rate for the TPNAC-group was substantially higher than for the group without TPNAC. It is suggested that development of TPNAC might lead to impairment of non-specific cellular immunity in neonates

Against the odds: an investigation into student persistence in UK higher education

© 2019, © 2019 Society for Research into Higher Education. This article focuses on student persistence in Higher Education. It examines qualities that enable students to persist in their studies despite the challenges they face, and key factors interplaying with and affecting these qualities. This study utilised the explanatory mixed-methods approach. It comprised a faculty-wide survey which explained the relationships between and across variables. Focus group interviews explored significant predictors of students’ persistence. Results from this study showed that, among other things, key drivers of student persistence were personal optimism, academic engagement, and positive relationships. Students’ decision to stay on and complete their studies determines their persistence; but there also remains a major role to be played by institutions. Successful student persistence tends to be a result of an intricate interaction between the student’s personal factors and their environment–and the institution is a key component of that environment

The Effects of Defamilisation and Familisation Measures on the Accumulation of Retirement Income for Women in the UK

This paper is concerned with the link between the effects of pro-market pension reforms on women and familisation/defamilisation measures. It aims to contribute to the study of this link in three ways. Firstly, it identifies defamilisation/familisation measures which have the potential to reduce negative effects of pro-market pension measures on women. Secondly, based on the examples from the UK, it shows that the government’s willingness to provide sufficient defamilisation/familisation measures to assist women to deal with the negative effects of the pro-market pension measures should not be taken for granted. Thirdly, it suggests ways for tackling this problem

Global Assemblages, Resilience, and Earth Stewardship in the Anthropocene

In this paper, we argue that the Anthropocene is an epoch characterized not only by the anthropogenic dominance of the Earth\u27s ecosystems but also by new forms of environmental governance and institutions. Echoing the literature in political ecology, we call these new forms of environmental governance “global assemblages”. Socioecological changes associated with global assemblages disproportionately impact poorer nations and communities along the development continuum, or the “Global South”, and others who depend on natural resources for subsistence. Although global assemblages are powerful mechanisms of socioecological change, we show how transnational networks of grassroots organizations are able to resist their negative social and environmental impacts, and thus foster socioecological resilience