20505 research outputs found
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Air quality and mental illness: role of bioaerosols, causal mechanisms and research priorities
Get PDFBackground:
Poor air quality can both trigger and aggravate lung and heart conditions, as well as affecting child development. It can even lead to neurological and mental health problems. However, the precise mechanisms by which air pollution affect human health are not well understood.
Aims:
To promote interdisciplinary dialogue and better research based on a critical summary of evidence on air quality and health, with an emphasis on mental health, and to do so with a special focus on bioaerosols as a common but neglected air constituent.
Method:
A rapid narrative review and interdisciplinary expert consultation, as is recommended for a complex and rapidly changing field of research.
Results:
The research methods used to assess exposures and outcomes vary across different fields of study, resulting in a disconnect in bioaerosol and health research. We make recommendations to enhance the evidence base by standardising measures of exposure to both particulate matter in general and bioaerosols specifically. We present methods for assessing mental health and ideal designs. There is less research on bioaerosols, and we provide specific ways of measuring exposure to these. We suggest research designs for investigating causal mechanisms as important intermediate steps before undertaking larger-scale and definitive studies.
Conclusions:
We propose methods for exposure and outcome measurement, as well as optimal research designs to inform the development of standards for undertaking and reporting research and for future policy.BioAirNet is a Natural Environment Research Council (NERC) funded network through the UKRI Strategic Priorities Fund Clean Air Programme (grant reference NE/V002171/1).BJPsych Ope
Dialectical perspective of truce-making processes: integrating women into close combat roles in the Armed Forces
No full textThis paper investigates the intricate process of integrating historically excluded social groups into long-established routines. Drawing on a dialectical perspective, the research explores how persistence and change emerge through the interplay of opposing forces, shedding light on the dynamics of integrating new participants while ensuring stability in established routines. The empirical focus is on an Armed Forces’ ground combat training (GCT) course, examining the integration of the first female officers after the formal ban on their participation in close-combat roles was lifted. The findings reveal a nuanced evolution of routine adaptation and truce reformation, characterized by three dialectical cycles: tentative truces, experimental truces, and enactment truces. These cycles involve negotiations between continuity and reformation, accommodation and resistance, and modification and preservation, uncovering a dialectical dance where organizational actors invest intense effort in maintaining the status quo while accommodating ambiguity and settling tensions. The findings extend our understanding of routine dynamics by illuminating the performative aspect of truce-making, highlighting the effortful processes involved in accommodating new participants. This paper establishes a connection between routines and dialectics, providing novel avenues for exploring complex organizational challenges and emphasizing micro-strategies employed by routine participants to address differences in practice. It also contributes to the field of organizational inclusion by offering a dialectical understanding of integration, showcasing the intricate dynamics involved in integrating historically excluded groups into established routines
Improving time transfer performance for low earth orbit satellites
Get PDFLow earth orbit (LEO) provides closer satellites with lower transmission losses and delays while struggling with a smaller field of view (FoV) and larger drag. The related works have been developed in the past utilising LEO satellites for positioning by relaying the signal from GNSS to the ground station. The following work addresses the timing aspect along with satellite positioning through ranging and limiting the position and velocity errors to provide control over the timing bias and drift errors. Using real-time two-line element (TLE) ephemeris data from a LEO satellite, the solution incorporates a linear Kalman filter to obtain predictions by updating the algorithm with a multilateration dataset from four known ground stations. The simulation dataset for satellite orbit propagation is used as ground truth to compare with the predictions and obtain position and velocity errors, leading to timing bias and drift. An error reduction of nearly 70 % was observed for position estimation, while an error reduction of nearly 30 % was found for the timing bias. The obtained value is within 0.5 ns of the 'LEO satellite positioning through the GNSS' technique. The proposed solution contributes to the evolving landscape of LEO navigation, improving positioning and timing measurement accuracy for satellite-based services.2024 IEEE International Instrumentation and Measurement Technology Conference (I2MTC
A novel hybrid electrochemical equivalent circuit model for online battery management systems
Get PDFAccurate battery modeling and parameter identification play pivotal roles in ensuring safety and reliability across the entire battery life cycle. Equivalent circuit models (ECM) are convenient but do not represent physical characteristics well; in contrast, electrochemical models with strong physical meaning are hard to parameterizing in an online setting. To address these challenges, this paper introduces a novel hybrid electrochemical Equivalent Circuit Model (eECM), which integrates electrochemical processes into an ECM, representing slow-dynamic internal processes with a simplified representation of solid- and liquid-phase diffusion; fast-dynamics are represented by ECM terms. The model is supported by an Adaptive Extended Kalman Filter (AEKF) to manage battery state changes and mitigate noise. To enhance parameter identification, a Fisher information matrix-enhanced Variable Forgetting Factor Recursive Least Squares (Fisher-VFFRLS) approach is employed, guided by the Cramér–Rao bound for identifying the most sensitive data points directly from the discharge cycle. Electrochemical parameters are determined via post-charging rest via a Genetic Algorithm (GA). The proposed methodology is validated on three dynamic cycles—DST, US06, and FUDS-demonstrates the effectiveness of the proposed eECM and parameter identification strategy, with maximum Root Mean Square Error (RMSE) for terminal voltage and State of Charge (SoC) estimation below 0.0076 and 0.0122, respectively.Journal of Energy Storag
Two-way coupled modeling of dislocation substructure sensitive crystal plasticity and hydrogen diffusion at the crack tip of FCC single crystals
No full textDislocation substructure-sensitive crystal plasticity (DSS-CP) modeling accounts for the evolution of mesoscale structures using dislocation-based parameters informed by experiments and computation at various lower length scales. To a first-order approximation, DSS-CP model parameters are affected by hydrogen (H) concentration, accounting for both H-dependent yield strength and strain hardening rate. This H-affected DSS-CP model is two-way coupled with H-diffusion to explore both effects of plastic deformation on H-diffusion and effects of H on yield strength and strain hardening in the DSS-CP model. Crack tip simulations are performed for face-centered cubic (FCC) metals under monotonic loading conditions with and without H. Enhanced maximum plastic deformation in the vicinity of the crack tip (i.e., localization or intensification of plastic strain) and crack tip opening displacement (CTOD) are predicted in the presence of H, consistent with experimental observations. In spite of increased initial strength due to H, subsequent reduction of the rate of strain hardening in the presence of H is shown to enhance localization of crack tip plasticity. Furthermore, this modeling framework predicts that higher H-diffusivity (leading to a larger H-affected zone) will enhance the crack tip plasticity, making use of the two-way coupling algorithm implemented in this work. On the other hand, we find that the H-sensitivity of crack tip strain localization response, based only on modification of model parameters, is too weak to explain typical experimental observations. This points to the need to develop more advanced DSS-CP constitutive relations that consider highly complex dislocation interactions with point defects.We acknowledge the financial support of the Fluor Marine Propulsion, LLC.International Journal of Solids and Structure
PTFE layer formation during brush electroplating of nickel
Get PDFBrush electrodeposition of Ni/PTFE composite coatings was explored using a nickel high speed solution and polytetrafluoroethylene (PTFE) particles 6–9 μm in diameter. A novel bilayer-like, partially intercalated structure was produced, consisting of a rough nickel sublayer covered by an outer, compact, smooth PTFE layer. The study of the coating growth revealed that the PTFE particles bind together on the nickel coating valleys and grow until all the surface is covered by a polymer layer without the need of a baking stage. The resulting coating presents a hydrophobic surface with a low coefficient of friction (0.10) and higher corrosion resistance to salt spray testing than the nodular nickel coating. The coatings were produced using an aqueous nickel plating solution, where the hydrophobic PTFE particles were suspended using different substances: cetrimonium bromide (CTAB) cationic surfactant, isopropyl alcohol premixed with the particles, and ethanol premixed with the particles. High concentrations of the suspending products were detrimental for the deposition process, but optimal values of 0.1 g/l, 3 ml/l and 3 ml/l respectively were found. All compounds successfully suspended the PTFE particles and both alcohols produced the Ni/PTFE coating described before, but the CTAB failed to co-deposit the polymer.This research has been funded jointly by Cranfield University and SIFCO Applied Surface Concepts under an Industrial Doctorate Scheme. The authors would like to acknowledge the work of Danijela Milosevic from SIFCO ASC on the salt spray testing. J.E. thanks the Spain Ministry of Science and Innovation for financially supporting the projects TED2021 132752B-I00, and PID2021-1287270B-I00.Scientific Report
Requirements uncertainty propagation in conceptual design using bayesian networks
Get PDFThis paper presents the application of a Bayesian Network as a tool for propagating the uncertainty between the aircraft-level design and the component-level design. The framework is applied to an example case in UAV design for payload transport. By querying the model, we demonstrate its ability to capture the casual relationships of the design problem and propagating the effects of design decisions on other parameters and requirements.This project has received funding from Innovate UK under Grant Agreement No 10003388.34th Congress of the International Council of the Aeronautical Sciences 202
Data for "Investigation into the environmental fate of the novel explosive 3-nitro-1,2,4-triazol-5-one (NTO): Acridine and its constituents"
No full text3-Nitro-l,2,4-triazol-5-one (NTO) is an Insensitive High Explosive (IHE) often considered as a safer alternative to traditional explosive 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). NTO is highly soluble in water and previous studies have revealed that when transported through soil it has the potential to create an environmental challenge as it tends to easily reach groundwater systems. To combat some of these challenges recent work has shown that combining NTO in a co-crystal with Acridine (ACR) at a molar ratio of 1:1 has a positive effect on thermal stability and a reduction in solubility. This paper experimentally evaluates the fate and transport of this NTO:ACR co-crystal compared to its individual components, NTO and ACR, in a low-inorganic matrix. The findings of this study reveal that despite NTO maintaining its high solubility within the co-crystal structure , the quantity of NTO retained within the upper layers of the sand column is larger for NTO:ACR. The rate of transport of these materials through the soil was also considered. While the rate of transport of NTO was proportional to its concentration the presence ACR was shown to have an antagonistic effect on this activity. Therefore, consistent evidence is provided here of an interaction between NTO and ACR within the co-crystal structure which results in a lower solubility for NTO. Increasing the retention of a containment within soil could aid in environmental remediation of the area post-use
The sustainability of reusing oil and gas produced water for agricultural irrigation in drylands
Get PDFProduced water (PW) is the largest waste stream generated from oil and gas
(O&G) extraction. Half of global PW (~8.5 km3 /year) is injected into deep disposal
wells or discharged on the surface. These practices are controversial due to their
environmental impacts causing increased regulation and cost. Meanwhile, water-
scarce drylands host significant O&G resources. Reusing PW in irrigation
provides an alternative to disposal options and could strengthen agriculture and
food security in drylands. However, uncertainties exist regarding the sustainability
of this practice. This research addresses these knowledge gaps by evaluating the
agro-environmental sustainability and the financial cost of reusing PW in
irrigation. First, the existing knowledge about PW irrigation is reviewed to identify
the agro-environmental risks posed by this practice and the uncertainties
regarding its sustainability. Second, irrigation with PW is simulated using a soil-
water model to identify the parameters related to the environment and to the
irrigation management which determine the sustainability of irrigation. Finally, a
framework combining irrigation modelling and a cost analysis is applied in both
regional and industrial case studies to identify agro-environmentally sustainable
irrigation strategies with PW and estimate their operating costs.
This research demonstrates that irrigation with PW can be agro-environmentally
sustainable if natural conditions are favourable such as on gypsum-rich draining
soils in the least arid climates. Furthermore, adapted management combining
irrigation at a little over the crop water needs (100–110% of the crop water needs)
and PW blending in a 1:1 up to 1:4 ratio with treated sewage effluent or
desalinated PW can achieve agro-environmentally sustainable irrigation by
preserving soil fertility, crop yield and groundwater quality. The cost of managing
PW in irrigation estimated between 1.09/m³ , is higher or within the cost
range of surface PW discharge and lower or within the cost range of injecting PW
into deep disposal wells. Further research is needed to test and validate the
modelling results in field conditions. A case-by-case approach is recommended
to assess the broader economic and social impacts of reusing PW in irrigation.PhD in Water, including Desig
Data for "Digital forensic science peer review survey UK and Norway"
No full textThe dataset represents a comparative study of peer review practices in the U.K. and Norway, contributing to the limited literature on quality assurance in digital forensics. Drawing on responses from 113 digital forensics practitioners and managers, the study offers valuable insights into their attitudes and approaches to quality control and highlights the contrasts between the two countries.
The following questions were asked:
Q1: What type of digital forensic organisation do you work for?
Q2: What is your role?
Q3: What is your professional background?
Q4: What is your highest academic degree?
Q5: How many years of experience do you have within the digital forensics discipline? (if
a year is not complete, round down).
Q6: Define what quality control in digital forensics means to you and the most relevant measures to implement it.
Q7: Do you think the quality control of case work in digital forensics is needed? (You can elaborate in the free field if needed).
Q8: In my unit, there is sufficient documentation available (such as procedures, routines, templates etc) that describes and supports appropriate measures for the maintenance of quality control of the digital forensic work performed at the unit.
Q9: In my unit, the examination reports undergo systematic quality control. This question concerns reports resulting from examination/analysis of digital data.
Q10: At my unit, we have enough time to perform quality control of the casework undertaken.
Q11: Quality control should be integrated into the work processes at digital forensics units.
Q12: Quality control of results prior to them being shared with the wider investigative team or officer in charge of a case, should be a natural part of the work flow in a digital forensic unit.
Q13: What is the role of those performing quality control of the case work performed at your unit?
Q14: Is the role of those performing quality control of the case work undertaken at your unit a dedicated ‘role’ assigned to certain individuals?
Q15: During the last 12 months, have you initiated processes for the quality control of your own case work?
Q16: At our unit, quality control of case work is performed at level 1, Administrative Check.
Q17: How many times during the last 12 months have you performed quality control of case work at level 1 (Administrative Check).
Q18: At our unit, quality control of reports is performed at level 2, Proof Check.
Q19: How many times during the last 12 months have you performed quality control of case work at level 2 (Proof Check) ? Q19:At our unit, quality control of reports is performed at level 3, Sense Review.
Q20: How many times during the last 12 months have you performed quality control of case work at level 3 (Sense Review).
Q21: At our unit, quality control of reports is performed at level 4, Conceptual Review.
Q22: How many times during the last 12 months have you performed quality control of case work at level 4 (Conceptual Review).
Q23: At our unit, quality control of reports is performed at level 5, Sampled Verification Review.
Q24: How many times during the last 12 months have you performed quality control of case work at level 5 (Sampled Verification Review).
Q25: At our unit, quality control of reports is performed at level 6, Full Verification Review.
Q27: How many times during the last 12 months have you performed quality control of case work at level 6 (Full Verification Review).
Q28: At our unit, quality control of reports is performed at level 7, Re-examination.
Q29: How many times during the last 12 months have you performed quality control of case work at level 7 (Re-examination).
Q30: Do you have any remarks