Database Analysis to Support Nutrient Criteria Development (Phase I)

The intent of this publication of the Arkansas Water Resources Center is to provide a location whereby a final report on water research to a funding agency can be archived. The Texas Commission on Environmental Quality (TCEQ) contracted with University of Arkansas researchers for a multiple year project titled “Database Analysis to Support Nutrient Criteria Development”. This publication covers the first of three phases of that project and has maintained the original format of the report as submitted to TCEQ. This report can be cited either as an AWRC publication (see below) or directly as the final report to TCEQ

Videos in STEM courses: A 21st century tool in higher education

The call for actively engaging students in the STEM classroom has increased to a clamour in recent years – in the field of biology, this is reflected through the call for student-centered learning in the 2011 AAAS Vision and Change document (http://visionandchange.org). The flipped classroom is arguably the most student-centered and interactive of the various active learning approaches. Central to this type of course are the instructional videos that students watch before class. While the concept of a flipped class may be of interest to many, the need to create these videos is often the perceived obstacle that prevents adoption of a flipped approach. Outside of the flipped classroom, there are a variety of other uses for instructor-created videos. In this presentation, we will discuss how we have incorporated instructional videos, lecture capture and screencasts in our flipped, blended and non-flipped courses. Participants will learn how simple these videos are to make and disseminate and will hear about the various types and uses of instructional videos. They will have the opportunity to debate the pros and cons of possibly the most controversial of instructional videos: lecture capture. Many dental and medical schools have been recording their lectures for years, yet this practice is not common in STEM education: why? The session will end with participants brainstorming possible uses for their own courses. In a follow-up workshop, we will provide hands-on experience to help participants make their own short instructional videos

Smart parcelization and place diversity: reconciling real estate and urban design priorities

This paper examines the meaning and significance of place diversity and explores how its achievement may well depend on specific institutional relations between different actors in the real estate development process. It calls for master developers to engage in the ‘smart parcelization’ of large development sites through design-sensitive subdivision, reflected in conditions attached to plot sales or leases. By looking at practical examples, it explores how this concept could refashion speculative housebuilding in the UK. The paper highlights the potential and limitations of ‘smart parcelization’, while emphasizing the need to link development and design considerations in future policy and research agendas

Gain limits of a Thick GEM in high-purity Ne, Ar and Xe

The dependence of the avalanche charge gain in Thick Gas Electron Multipliers (THGEM) on the purity of Ne, Ar and Xe filling gases was investigated. The gain, measured with alpha-particles in standard conditions (atmospheric pressure, room temperature), was found to considerably drop in gases purified by non-evaporable getters. On the other hand, small N2 admixtures to noble gases resulted in high reachable gains. The results are of general relevance in the operation of gas-avalanche detectors in noble gases, particularly that of two-phase cryogenic detectors for rare events.Comment: 15 pages, 6 figures, submitted to JINS

Ownership diversity and fragmentation: a barrier to urban centre resilience

Fragmentation of ownership has long been a recognised constraint to UK city centre development, a complexity that is growing in significance as centres try to manage the decline in physical retailing and transform obsolete retail units. Yet, our understanding of the structure of ownership and how that might be facilitating or inhibiting urban change remains weak. In this paper, the objective is to address this gap by examining the structure and diversity of land ownership in five retailing centres - Edinburgh, Glasgow, Hull, Liverpool, and Nottingham – between 2000–2017 using original databases created by linking administrative and commercial property data sets. Overall, the analysis finds property ownership to be spatially complex with ownership richness and diversity generally rising over the study period. The study also reveals that ownership structure has been shifting away from financial institutions towards overseas investors, private individuals and unlisted property companies, implying greater fragmentation of ownership. While the greater diversity in ownership should stimulate competition and innovation in property market practices, the shift in balance from equity-rich larger investors towards smaller and sometimes unknown investors makes urban centre management harder to manage. This suggests policymakers need to rethink the urban governance model to find a better way to galvanise the actions of this increasing disparate group of stakeholders if their visions of more resilient, mixed use city centres are to be realised

Changing tenant covenant perceptions and flexibility in the lease model in UK city centres

The retailing industry in the UK is experiencing unprecedented structural change. The impact on retailers has often dominated headlines, along with the impacts on local services and economies, but with little attention given to the implications for property owners and practitioners. Exploring and understanding the responsiveness of landlords, and their behaviours, is essential to understanding the adaptiveness of a retailing system. This study employs semi-structured interviews to examine the short- and long-term changes in the retail market and the actions of landlords in response. The findings span the period prior to and during the first year of the Covid-19 pandemic in 2020, and reveal that fundamental changes have occurred to establish tenant covenant norms and the traditional retail leasing model. The paper explores these changes, including a shift in tenant risk, reposition of the leasing model in favour of tenants, generally, and greater application of turnover rents. The pressing challenge for current valuation practitioners, therefore, is to incorporate these fundamental changes within the market into the pricing of retail assets. Significant progress in this area to date, as explored in the paper, has been limited although greater application of discounted cashflow techniques is set to be encouraged by the RICS

THGEM operation in Ne and Ne/CH4

The operation of Thick Gaseous Electron Multipliers (THGEM) in Ne and Ne/CH4 mixtures, features high multiplication factors at relatively low operation potentials, in both single- and double-THGEM configurations. We present some systematic data measured with UV-photons and soft x-rays, in various Ne mixtures. It includes gain dependence on hole diameter and gas purity, photoelectron extraction efficiency from CsI photocathodes into the gas, long-term gain stability and pulse rise-time. Position resolution of a 100x100 mm^2 X-rays imaging detector is presented. Possible applications are discussed.Comment: Submitted to JINST, 25 pages, 33 figure

Critical Exponents for Three-Dimensional Superfluid--Bose-Glass Phase Transition

The critical phenomenon of the zero temperature superfluid--Bose-glass phase transition for hard-core bosons on a three-dimensional disordered lattice is studied using a quantum real-space renormalization-group method. The correlation-length exponent $\nu$ and the dynamic exponent z are computed. The critical exponent z is found to be 2.5 for compressible states and 1.3 for incompressible states. The exponent $\nu$ is shown to be insensitive to z as that in the two-dimensional case, and has value roughly equal to 1.Comment: 11 pages, REVTE