Recovering resources from abandoned metal mine waters : an assessment of the potential options at passive treatment systems

PhD Thesis Appendices can be consulted at the Philip Robinson Library.Remediation of metal-rich discharges from abandoned mines entails capture of metals within a treatment system and, typically, disposal of the waste. A preferable option would be to recover the metals for reuse. For many long-abandoned mines metal loads are often relatively small, albeit they often cause significant environmental pollution. Low-cost passive treatment systems, in which metals are retained in some form of treatment substrate, such as compost, are often preferred. This thesis investigates the amenability of such treatment systems to resource recovery. Two down-flow compost bioreactors, treating zinc-rich discharges, were the focus of the research: a pilot-scale unit at Nenthead, and a full-scale system at Force Crag, both in Cumbria, England. Laboratory investigations of the Nenthead substrate identified 7,900mg/kg zinc in the upper horizons of the substrate, and 2,400mg/kg in the lower horizons, after two years of operation. Acid leaching tests effectively de-contaminated the substrate with respect to zinc and cadmium. Complete recovery of zinc was observed after ≤30 hours across a range of acid leach tests, although 23-37 days were required before equivalent recovery was achieved by biological leaching. The Force Crag system removed >95% zinc over the first year of operation and, removal rates suggest that after 10 years of operation >20,000mg/kg zinc will have accumulated in the substrate. Substrate de-contamination could offer substantial life-cycle cost savings at passive treatment sites, especially by limiting volumes of material for disposal to landfill. Furthermore, recovery of metals has important implications for resource sustainability and circular economics. Other resource recovery options may exist at abandoned mine sites. At Force Crag 1.6kW of kinetic energy exists in flowing mine water, in addition to thermal energy which could be recovered for space heating applications. Recovering this energy would convert this site into a net-generator of power. Because of their often remote locations, renewable energy may be of particular value to off-grid facilities at some mine sites.partially funded by The Coal Authorit

Human Resource Development and Career and Technical Education in American Community Colleges

With their open access admission policies, low tuition costs, and convenient locations, community colleges are designed to make college accessible to all. They strive to meet three main goals. The first is to teach marketable vocational skills, the second is to provide the first two years of a four-year bachelor’s degree program, and the third is to provide continuing education and enrichment for community residents. This paper covers issues that are relevant to the community college mission of helping prepare a skilled workforce for jobs offering reasonable wages. After providing an overview about community colleges and their students, the paper discusses the types of remedial education programs that are most likely to provide the large number of underprepared students enrolled in community colleges with the skills to advance to college-level courses. It considers the growing phenomenon of dual enrollment that enables students to earn both high school and college credit for courses while still in high school. It addresses the ways that community colleges can support local labor markets and regional economic development and their efforts to build career pathways for workers. It describes the growing role of community colleges in online education, and it reviews the financing of community colleges. The paper also discusses issues related to community college persistence and completion, and it cites evidence of the market value of the education and credentials the colleges provide. Finally, it considers the usefulness of the American community college as a model for other countries seeking to develop institutions that serve similar functions

Interactions between RAMP2 and CRF receptors: The effect of receptor subtypes, splice variants and cell context.

Corticotrophin releasing factor (CRF) acts via two family B G-protein-coupled receptors, CRFR1 and CRFR2. Additional subtypes exist due to alternative splicing. CRFR1α is the most widely expressed subtype and lacks a 29-residue insert in the first intracellular loop that is present in CRFR1β. It has been shown previously that co-expression of CRFR1β with receptor activity modifying protein 2 (RAMP2) in HEK 293S cells increased the cell-surface expression of both proteins suggesting a physical interaction as seen with RAMPs and calcitonin receptor-like receptor (CLR). This study investigated the ability of CRFR1α, CRFR1β and CRFR2β to promote cell-surface expression of FLAG-tagged RAMP2. Four different cell-lines were utilised to investigate the effect of varying cellular context; COS-7, HEK 293T, HEK 293S and [ΔCTR]HEK 293 (which lacks endogenous calcitonin receptor). In all cell-lines, CRFR1α and CRFR1β enhanced RAMP2 cell-surface expression. The magnitude of the effect on RAMP2 was dependent on the cell-line ([ΔCTR]HEK 293 > COS-7 > HEK 293T > HEK 293S). RT-PCR indicated this variation may relate to differences in endogenous RAMP expression between cell types. Furthermore, pre-treatment with CRF resulted in a loss of cell-surface FLAG-RAMP2 when it was co-expressed with CRFR1 subtypes. CRFR2β co-expression had no effect on RAMP2 in any cell-line. Molecular modelling suggests that the potential contact interface between the extracellular domains of RAMP2 and CRF receptor subtypes is smaller than that of RAMP2 and CRL, the canonical receptor:RAMP pairing, assuming a physical interaction. Furthermore, a specific residue difference between CRFR1 subtypes (glutamate) and CRFR2β (histidine) in this interface region may impair CRFR2β:RAMP2 interaction by electrostatic repulsion

Co-benefits of urban climate action: a framework for cities

Why do climate co-benefits matter for cities? • The evidence suggests that citizens are more likely to take action on climate change, or more likely to support governments that take action on climate change, if the wider co-benefits of those actions are emphasised. • At the same time, policies that are aimed at supporting innovation, delivering economic benefits and enhancing the quality of life of citizens can potentially lead to major climate cobenefits (e.g. reduced greenhouse gas emissions) which would be more challenging to achieve if climate action were the primary objective. • At the city level, the potential of co-benefits is particularly great as citizens can often witness the results of policy actions more directly on their daily lives. Definition and taxonomy of co-benefits • The term co-benefits has a wide range of definitions in the climate literature, with over 20 terms identified in the literature that are used synonymously or in a similar context. • The term co-benefits varies in intentionality (e.g. is climate the primary or secondary objective, or simply an unintentional benefit?), scope (e.g. does it include mitigation benefits, adaptation benefits or both?), and scale (e.g. are the benefits short term and local, or long term and global?). • Co-benefits may be (1) secondary benefits from climate policy action, (2) secondary climate benefits from other policy actions, or (3) the combination of climate and non-climate benefits; both of which are targeted under an integrated policy programme. • The wide range of established definitions of co-benefits used by authoritative organisations means that formulating a taxonomy of co-benefits with broad buy-in from policy makers is challenging. Results of literature review • Health, Land Use and Transport were the top three sectors for the number of co-benefits, with over 40 co-benefits identified in each. • Waste, Air Quality, Transport and Energy had particularly high numbers of mitigation cobenefits in the literature reviewed. Adaptation co-benefits were particularly strong for Disaster and Emergency, Food Security and Tourism, Culture and Sport. Land Use, Health, Water and Education tended to be strong for both mitigation and adaptation co-benefits

From College To Jobs: Making Sense of Labor Market Returns To Higher Education

This report summarizes key findings from recent research on links between higher education and the workforce. Featuring eight brief papers from leading education and workforce experts from around the country, the report offers practical advice for institutional leaders, policymakers, students and their advisers about how to use the increasingly available information on the economic value of higher education. Specifically, the authors' papers and the opening summary explore what various audiences can learn from emerging evidence about: variations in labor market outcomes by program and institution; the value of degrees to jobs both in and out of fields studied; returns to the completion of certain course clusters that don't add up to a degree; and distortions that may result from examining returns to individual degrees rather than "stacked" degrees

Implementing an electronic sideband offset lock for precision spectroscopy in radium

We demonstrate laser frequency stabilization with at least 6 GHz of offset tunability using an in-phase/quadrature (IQ) modulator to generate electronic sidebands (ESB) on a titanium sapphire laser at 714 nm and we apply this technique to the precision spectroscopy of $^{226}$Ra, and $^{225}$Ra. By locking the laser to a single resonance of a high finesse optical cavity and adjusting the lock offset, we determine the frequency difference between the magneto-optical trap (MOT) transitions in the two isotopes to be $2630.0\pm0.3$ MHz, a factor of 29 more precise than the previously available data. Using the known value of the hyperfine splitting of the $^{3}P_{1}$ level, we calculate the isotope shift for the $^{1}S_{0}$ to $^{3}P_{1}$ transition to be $2267.0\pm2.2$ MHz, which is a factor of 8 more precise than the best available value. Our technique could be applied to countless other atomic systems to provide unprecedented precision in isotope shift spectroscopy and other relative frequency comparisons

Demonstrating the validity of the Video Game Functional Assessment-Revised (VGFA-R)

Problematic video play has been well documented over the course of the last decade. So much so the DSM-5 (APA, 2013) has included problematic video gaming as disorder categorized as Internet Gaming Disorder. The field of applied behavior analysis has been utilizing functional assessments for the last 30 years and has showed evidence of effective results across different populations and environments. Therefore, the purpose of this investigation (comprising three studies) was to validate an indirect functional assessment entitled the Video Game Functional Assessment-Revised (VGFA-R). Using academic experts in the field of video game addiction and applied behavioral analysis (n=6), the first study examined the content validity of the VGFA-R and was able to demonstrate the assessment exceeded the criterion for an established assessment. A second study comprising a survey of 467 gamers examined the factorability by using a confirmatory factor analysis, and found that VGFA-R had an overall variance above .60. Within the third laboratory-based study using gamers (n=11), the VGFA-R was examined for construct validity and found the VGFA-R was able to predict 85% of the appropriate function of behavior. Implications of the study are discussed along with the strengths and limitations of the study and future research directions