20505 research outputs found
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Establishing acceptable exposure limits for Escherichia coli in WWTP tailwater discharge for recreational activities
No full textTailwater discharged from wastewater treatment plants (WWTPs) can contain pathogenic microorganisms, posing potential health risks during recreational water activities. While Quantitative Microbial Risk Assessment (QMRA) is commonly used to evaluate these risks, its complex outputs were not easily translated into operational standards. To address this gap, this study introduces the concept of a threshold limit value (TLV) defined as the maximum acceptable E. coli concentration in tailwater that ensures compliance with specific health risk benchmarks. TLVs were derived using reverse QMRA for four age groups (children, early teens, teens, and adults) under two risk criteria: the U.S. EPA annual infection risk (10−4) and the World Health Organization disease burden benchmark (10−6 DALYs per person per year). Results showed that TLVs decrease with age, as adult individuals inhale or ingest larger volumes, resulting in higher exposure doses under identical conditions. Consequently, lower TLVs indicate stricter health protection requirements. WWTPs with higher treatment capacity and larger receiving water flows exhibited lower TLVs, reflecting more stringent acceptable concentrations due to reduced exposure risk. Swimming TLVs (4.43E+01–7.72E+02 CFU/100 mL) were about three times lower than rowing TLVs (1.25E+02–1.09E+03 CFU/m3), based on WHO and U.S. EPA benchmarks, due to more direct exposure and higher contact frequency. TLVs based on the WHO benchmark were consistently lower than those based on the EPA benchmark, emphasizing the impact of risk criteria on regulatory limits. Sensitivity analysis identified annual exposure frequency as the dominant variable for both rowing and swimming, with exposure time also being a key determinant for swimming exposure. This study provides a practical, risk-based framework for defining site-specific microbial limits, supporting evidence-based water quality management.This study was sponsored by the Environmental Microbiology and Human Health Programme (Grant Reference NE/M010961/1); the SPF Clean Air Programme Grant NE/V002171/1Risk Analysi
Managing complex projects
No full textComplexity is an issue that affects all projects. Project managers know this, but it can be difficult to express the realities they face in a language that others can easily grasp. In this chapter we draw on research that identifies three different kinds of project complexity – structural, socio-political, and emergent, and look at practical response techniques to these.
We offer a complexity framework to help managers deal with these challenges. We then show how this can be used both as a problem-solving tool, and also as a method to draw out lessons learned at gate reviews or at the completion of the work
Promoting resilient and sustainable food systems: a systematic literature review on short food supply chains
No full textPurpose
This review aims to comprehensively analyze the Short Food Supply Chain (SFSC) model, which connects local food producers directly with consumers. By exploring participation factors, sustainable practices, challenges, economic impacts, and social benefits, this study seeks to provide a thorough understanding of SFSCs. Addressing gaps in existing research, the review aims to guide policymakers and practitioners in fostering sustainable, resilient, and inclusive local food systems.
Design/methodology/approach
A systematic literature review of 92 research articles was conducted following a well-defined research protocol.
Findings
The review revealed that factors driving the adoption of SFSCs include increasing consumer demand for local and sustainable products, resilience-building in the food system, and environmental concerns. The SFSC supply chain was categorized into four critical stages: food sourcing and production, processing, aggregation, and distribution and review examined the sustainable practices at each stage. However, challenges such as information asymmetry, lack of infrastructure, regulatory barriers, and market dynamics hinder the full potential of SFSCs. Economically, SFSCs contribute to local economic development and empowerment of small-scale producers, while also showing promise in reducing environmental footprints and fostering community engagement.
Research implications
The study identifies several research avenues to further advance the understanding of SFSCs. Future research should delve into consumer behavior and attitudes towards SFSCs, analyze the full sustainability impacts of SFSCs using integrated assessment methodologies, and extend the study to different regional contexts. Additionally, investigating policy interventions and governance mechanisms that can support the growth and resilience of SFSCs will be crucial for promoting sustainable agricultural practices.
Originality/value
This review contributes to the existing literature by providing a comprehensive and systematic overview of SFSCs, addressing gaps left by previous review studies. The study's findings offer valuable insights for policymakers, researchers, and stakeholders seeking to enhance the adoption and support of SFSCs in contemporary food systems
Improvised explosives how to understand the threat and assess the risks
No full textPartner institution Royal Military Academy, BelgiumThe research undertaken for this thesis has contributed to address the risk posed by dual-use industrial chemicals as improvised explosives in Improvised Explosive Devices (IEDs). The novelty of this work was the investigation of the detonation properties of Urea - Hydrogen Peroxide (UHP), an oxidiser widely used in the cosmetic and pharmaceutical industries as a solid source of hydrogen peroxide, identified as a potential emerging threat, with very limited academic literature available on its explosive properties. This research project, which includes 150 instrumented firings, was also one of the first attempts to thoroughly characterise a tertiary explosive for risk assessment purposes. The detonability of UHP at small scale was first investigated, successfully validating an experimental setup and a charge geometry that closely approached large-scale behaviour and proved suitable to study other energetics. Consistent detonation performance parameters at large and small scale were determined from complementary experimental approaches, thermochemical calculations and numerical simulations. The collected academic data were further analysed in a Counter-IED (C-IED) perspective within the scope of a limited release technical-operational threat assessment (not included in this manuscript). This work has also provided valuable insights into the non-ideality of UHP, highlighting the limitations of the available characterisation methods and modelling tools. In terms of real-world impact, the results published in this body of work provide relevant knowledge to the scientific community, complementing the rather limited available academic literature with a comprehensive characterisation of UHP detonation performance. The outcome is also of great interest for the industrial risk management and process safety. This work was equally important to understand the threat and assess the risk posed by tertiary explosives in a C-IED context and address relevant recommendations to the worldwide intelligence services and the law-enforcement agencies
Effect of CW-GMA welding on the HAZ and mechanical properties of structural steel
No full textThis work investigated the effect of cold wire gas metal arc welding (CW-GMAW) on the heat-affected zone (HAZ) and mechanical properties of structural steel designated as BS 970 Part 3:1991 080A15 steel. The study involved feeding cold ER70S-6 wire into the welding arc of energised hot wire (HW). Welds were produced at cold wire feed speeds (CWFS) of 2, 4, and 6 m per min labelled CW2, CW4, and CW6, and were compared with conventional welds (CW0) and the parent metal (PM). Metallographic examination, hardness testing, and cross joint tensile evaluation were carried out. Cold wire (CW) addition resulted in a more gradual cooling profile which increased the width of heat-affected sub-zones particularly the grain refined zone (GRZ). Hardness decreased across all weld zones with increasing CWFS indicating improved ductility and reduced potential for brittle phase formation. Although the 0.2% proof stress reduced by about 16% relative to the parent metal (PM), the tensile strength at CW6 approached that of the base material. Ductility loss of 35% in CW0 reduced to 22% in CW welds representing a 13-point improvement. For CW6, the tensile fracture location shifted from the partially transformed zone (PTZ) to the PM close to PTZ region confirming improved mechanical performance. However, at higher CWFS, weld penetration decreased due to reduced arc energy density. The study demonstrates that CW addition can improve ductility and tensile performance in conventional GMA welds while increasing productivity when welding parameters and joint design are optimised.Welding in the Worl
Reading between presidential lines - An examination of morally embedded US governmental narrative allied to the approval and employment of selected counter-terrorism tactics
No full textPlease contact the Barrington Library Reports Section for access to this document. Send the details of the document to [email protected] and mark your request FAO Shrivenham.In the aftermath of 9/11, President Bush stated in a national television address ‘We will find those responsible and bring them to justice’.1 These words, reassuringly defiant and globally reaching, would set the course of US history for the next 15 years in their pursuit of terrorists across the globe. However, by applying linguistic analysis in the form of Speech Act Theory, these words also imply a contract of response between the American population and its Government to respond to acts of terrorism and present a self-generated pre-approval to undertake some sort of action – an alibi before the act has been committed. Speech Act Theory will highlight that this authority is not dependent by the severity of the terrorist attack, nor is the timeline between terrorist attack and delivery of justice affected by the limitations of a Presidential term of office; the words that make up the alibi remain enduring until the perpetrators are held to account. The application of Speech Act Theory will furthermore reveal that justification has been inherently embedded to Presidential narrative and policy documents in an effort to appease the recipient that the threat from international terrorism is being countered; and that this veiled justification is for the use of selected counter-terrorism tactics in the form of extraordinary rendition, enhanced interrogation techniques, targeted military strikes including the use of armed Remotely Piloted Aircraft. The justification to use these tactics is not new and dates back the Reagan Administration when counter-terrorism was a relatively new concept for the US Government to undertake. This unique approach presents Speech Act Theory as additional methodology to the understanding of actions by the US in their response to terrorism in addition to the principles of Just War Theory and the Law of Armed Conflict
Strengthening community disaster resilience in uncertain times: a multi-level analysis of an Australian bushfire
No full textThis paper examines how community groups develop resilience over time through influencing and interacting with different societal levels throughout the phases of the disaster management cycle: prevention, preparation, response, and recovery. This provides an opportunity for a more insightful and holistic understanding of the factors involved in resilience. The macro/governmental level shapes governance of bushfire management and resources; the micro level reflects the actions of individual and households; while the meso-level represents local community groups providing a bridge between the two through trust-based integration and collaboration.
This four-year longitudinal study used a complexity analysis framework to reveal latent tensions, as well as strong social relationships and community connections. These had implications for the emergent, local-specific responses to the bushfires, based on community attributes, needs and characteristics. The work reveals the importance of the meso level as a bridge between the governmental and individual levels, which can support tailoring, reconfiguring, and organising resources to strengthen resilience. These findings also have implications for shared responsibility, as community-based organisations may disagree with objectives at other levels, eroding resilience across the entire system. The analysis in this paper indicates that careful, flexible integration of the locally specific knowledge, meso-level coordination, relationship-building, and transparent information-sharing that community-based organisation can provide, can be beneficial in effectively managing the multiple complexities of disasters.This research received funding support from the University of Wollongong Global Challenges Program and the Shark Island Institute.International Journal of Disaster Risk Reductio
Microbial population and distribution at a Mars Analog Alluvial Plain in Dyngjusandur, Iceland
No full textThe limited nutrient availability, extreme temperatures, and desiccation of Arctic volcanic regions provide a unique opportunity to study environments with multiple similarities to extraterrestrial systems. Dyngjusandur, Iceland, is a plain of nutrient-poor volcanic basaltic tephra shaped by alluvial and aeolian action, sharing spectroscopic similarities to analogous geological features observed on Mars. To obtain spatial information at different scales, two regions of the Dyngjusandur plain separated by 1 km and selected for their homogeneous appearance were sampled in this study. Sampling schemes each consisted of nested triangular grids of samples beginning at the 0.1 m scale and increasing to the 100 m scale. Additional samples were recovered in 1 cm increments to a depth of 7 cm. Biological and geophysical analyses were performed including 16S rRNA gene qPCR, DNA quantification, amplicon sequencing, moisture quantification, and separation of grain size fractions. The two sampling sites were found to have significantly different dsDNA content by the t-test (p-value = 0.001) and the Mann–Whitney u-test (p-value = 0.003). The DNA content (a proxy for biomass) showed the greatest variation at 10 m of sample separation, and both total dsDNA content and bacterial 16S rRNA gene copies showed significant correlations with sample grain size. Grain size distribution also appeared to influence the abundance of several bacterial phyla, with positive and negative correlations observed, though the same dominant phyla were observed across all samples studied. This work suggests that, in seemingly homogeneous environments undergoing aeolian resurfacing, the averages from a sample set collected at small spatial separation (1–10 m) may be sufficient to define baseline levels of biomass present and the abundances of the most prominent phyla on a larger (100 m–1 km) scale. However, sampling a larger site at smaller intervals (10 m) provides important characterization of site heterogeneity with diminishing information returns at increasingly smaller intervals (≤1 m).The field work was supported by the Lewis and Clark Exploration fund, Oak Ridge Associated Universities, Cranfield University, and the Open University. Financial support was provided by the State of Georgia, the Georgia Institute of Technology, Atlanta, GA, NASA postdoctoral program, and NASA ROSES PSTAR Grant NNX16AK13G.Some of this work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004).ACS Earth and Space Chemistr
Global classification of wave height, period, and direction multivariate distributions using principal component analysis
No full textResearch on the classification of ocean surface wave patterns uses coarse spatial resolutions and approaches that are less usable for applications such as annual energy estimates for wave energy converters. Consequently, this study investigates the classification of 1–3-dimensional histograms of wave height, period, and direction at a 0.4° spatial resolution. Histograms of global grid-points have been decomposed into their main modes using principal component analysis. Each mode consists of a histogram and a map quantifying its contribution to each local wave pattern. The first mode displayed a meridional gradient of the wave height, a northeast-to-southeast gradient of the wave period, and a mix of both for the wave direction. Dominating wave systems consist of a) 1.9 m, b) 14.5 s in the basins’ southeast, c) 12.5 s north and south, and d) 9.5 s north-west. Generated remotely, c) travel and evolve over long distances to reach coasts, as b) pools, while d) is mainly generated locally or northwards. K-means was used to cluster wave patterns into 15 classes using the 10 dominant modes. Some clusters characterise regions in different basins. 1-parameter-based clusters provide more regions and alternations of clusters nearshore, while clustering the parameters together provides larger regions and less nearshore noise. The wave height and period combined classification showed good correlation and difference between the cluster's average histogram and those of the grid-points in that cluster, while the direction was lower in regions affected by strong currents or topographic obstacles. Consequently, combining all parameters greatly decreases these two metrics.The main author started this research in 2018 while receiving the Postgraduate Research Scholarships from Griffith University. This specific research then got financed by a scholarship processo 88887.614992/2021–0 from CAPES (Coordenaçao de Aperfeicoamento de Pessoal de Nível Superior) /PROEX (Programa de Excelencia Academica), later replaced by two FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) scholarships, processos n° 2022/06765–8 and n° 2022/13873–1. This work was also supported by ISblue project, Interdisciplinary graduate school for the blue planet (ANR-17-EURE-0015) and co-funded by a grant from the French government under the program “Investissements d'Avenir” embedded in France 2030.Progress in Oceanograph
Analysis of Space-Flight Radiation Damage to ExoMars Trace Gas Orbiter NOMAD-UVIS Spectrometer
No full textDryer, Ben – Associate Supervisor – Open University
Mason, Jon – Associate Supervisor – Open UniversityExoMars Trace Gas Orbiter (TGO) mission, launched in 2016 as part of the European Space Agency (ESA) ExoMars programme, carries the Nadir and Occultation for MArs Discovery (NOMAD) instrument suite which consists of the Ultraviolet and Visible Spectrometer (UVIS). Operating in Martian orbit, NOMAD-UVIS is subject to accumulating radiation-induced degradation that can impact detector performance and long-term data quality. This study explores radiation-induced damage to NOMAD-UVIS through an analysis of dark current evolution, integrating both pre-flight ground testing data and in-flight mission data. The results establish a comparison between ground test predictions of radiation-induced dark current via the use of estimated radiation doses, and the actual in-flight performance of the detector with consideration of the Martian radiation environment.MSc in Astronautics and Space Engineerin