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Journal articleZhou L, Liu F, Liu Q, et al., 2021,
Aluminum increases net carbon fixation by marine diatoms and decreases their decomposition: Evidence for the iron-aluminum hypothesis
, LIMNOLOGY AND OCEANOGRAPHY, Vol: 66, Pages: 2712-2727, ISSN: 0024-3590 -
Journal articleLupatsch JE, Kreis C, Konstantinoudis G, et al., 2021,
Birth characteristics and childhood leukemia in Switzerland: a register-based case-control study
, CANCER CAUSES & CONTROL, Vol: 32, Pages: 713-723, ISSN: 0957-5243- Cite
- Citations: 10
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Journal articleFolly CL, Konstantinoudis G, Mazzei-Abba A, et al., 2021,
Bayesian spatial modelling of terrestrial radiation in Switzerland
, JOURNAL OF ENVIRONMENTAL RADIOACTIVITY, Vol: 233, ISSN: 0265-931X- Author Web Link
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- Citations: 11
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Journal articleDhokotera T, Bartels L, Rohrer E, et al., 2021,
Spatiotemporal modelling and mapping of cervical cancer incidence among HIV positive women in South Africa: a nationwide study
, International Journal of Health Geographics, Vol: 20, Pages: 1-12, ISSN: 1476-072XBackgroundDisparities in invasive cervical cancer (ICC) incidence exist globally, particularly in HIV positive women who are at elevated risk compared to HIV negative women. We aimed to determine the spatial, temporal, and spatiotemporal incidence of ICC and the potential risk factors among HIV positive women in South Africa.MethodsWe included ICC cases in women diagnosed with HIV from the South African HIV cancer match study during 2004–2014. We used the Thembisa model, a mathematical model of the South African HIV epidemic to estimate women diagnosed with HIV per municipality, age group and calendar year. We fitted Bayesian hierarchical models, using a reparameterization of the Besag-York-Mollié to capture spatial autocorrelation, to estimate the spatiotemporal distribution of ICC incidence among women diagnosed with HIV. We also examined the association of deprivation, access to health (using the number of health facilities per municipality) and urbanicity with ICC incidence. We corrected our estimates to account for ICC case underascertainment, missing data and data errors.ResultsWe included 17,821 ICC cases and demonstrated a decreasing trend in ICC incidence, from 306 to 312 in 2004 and from 160 to 191 in 2014 per 100,000 person-years across all municipalities and corrections. The spatial relative rate (RR) ranged from 0.27 to 4.43 in the model without any covariates. In the model adjusting for covariates, the most affluent municipalities had a RR of 3.18 (95% Credible Interval 1.82, 5.57) compared to the least affluent ones, and municipalities with better access to health care had a RR of 1.52 (1.03, 2.27) compared to municipalities with worse access to health.ConclusionsThe results show an increased incidence of cervical cancer in affluent municipalities and in those with more health facilities. This is likely driven by better access to health care in more affluent areas. More efforts should be made to ensure equitable access to health services
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ReportAunedi M, Wills K, Green T, et al., 2021,
Net-zero GB electricity: cost-optimal generation and storage mix
, Great Britain's electricity generation capacity mix for net-zero carbon emissions, Publisher: Energy Futures Lab -
Journal articleBucci A, Garcia-Tecedor M, Corby S, et al., 2021,
Self-supported ultra-active NiO-based electrocatalysts for the oxygen evolution reaction by solution combustion
, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 9, Pages: 12700-12710, ISSN: 2050-7488- Cite
- Citations: 29
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ReportLawrance E, Thompson R, Fontana G, et al., 2021,
The impact of climate change on mental health and emotional wellbeing: current evidence and implications for policy and practice
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Journal articleYin Z, Chen B, Cao XE, et al., 2021,
Young martlets: Exploring the world of academia and beyond
, Matter, Vol: 4, Pages: 1434-1436, ISSN: 2590-2393The Martlets Society (www.martlets-society.com) is an independent non-profit organization found and run by young scholars. It aims to build a free and equal community for young scholars to build connections and have interdisciplinary exchanges. It currently holds talks and events with diverse topics to show young scholars the world of academia and beyond. It is also planning more events for the equality in education and academia.
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Journal articlePhillipson L, Li Y, Toumi R, 2021,
Strongly coupled assimilation of a hypothetical ocean current observing network within a regional ocean-atmosphere coupled model: an OSSE case study of typhoon hato
, Monthly Weather Review, Vol: 149, Pages: 1317-1336, ISSN: 0027-0644The forecast of tropical cyclone (TC) intensity is a significant challenge. In this study, we showcase the impact of strongly coupled data assimilation with hypothetical ocean currents on analyses and forecasts of Typhoon Hato (2017). Several observation simulation system experiments (OSSE) were undertaken with a regional coupled ocean–atmosphere model. We assimilated combinations of (or individually) a hypothetical coastal current HF radar network, a dense array of drifter floats, and minimum sea level pressure. During the assimilation, instant updates of many important atmospheric variables (winds and pressure) are achieved from the assimilation of ocean current observations using the cross-domain error covariance, significantly improving the track and intensity analysis of Typhoon Hato. Relative to a control experiment (with no assimilation), the error of minimum pressure decreased by up to 13 hPa (4 hPa/57% on average). The maximum wind speed error decreased by up to 18 kt (5 kt/41% on average) (1 kt ≈ 0.5 m s−1). By contrast, weakly coupled implementations cannot match these reductions (10% on average). Although traditional atmospheric observations were not assimilated, such improvements indicate that there is considerable potential in assimilating ocean currents from coastal HF radar and surface drifters within a strongly coupled framework for intense landfalling TCs.
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Journal articleKonstantinoudis G, Padellini T, Bennett J, et al., 2021,
Response to "re: long-term exposure to air-pollution and COVID-19 mortality in England: a hierarchical spatial analysis"
, Environment International, Vol: 150, ISSN: 0160-4120 -
Journal articleRao RR, Huang B, Katayama Y, et al., 2021,
pH- and Cation-Dependent Water Oxidation on Rutile RuO<sub>2</sub>(110)
, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 125, Pages: 8195-8207, ISSN: 1932-7447- Cite
- Citations: 96
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Journal articleSmith M, Toumi R, 2021,
Using video recognition to identify tropical cyclone positions
, Geophysical Research Letters, Vol: 48, Pages: 1-9, ISSN: 0094-8276Tropical cyclone (TC) center fixing is a challenge for improving forecasting and establishing TC climatologies. We propose a novel objective solution through the use of video recognition algorithms. The videos of tropical cyclones in the Western North Pacific are of sequential, hourly, geostationary satellite infrared (IR) images. A variety of convolutional neural network architectures are tested. The best performing network implements convolutional layers, a convolutional long short-term memory layer, and fully connected layers. Cloud features rotating around a center are effectively captured in this video-based technique. Networks trained with long-wave IR channels outperform a water vapor channel-based network. The average position across the two IR networks has a 19.3 km median error across all intensities. This equates to a 42% lower error over a baseline technique. This video-based method combined with the high geostationary satellite sampling rate can provide rapid and accurate automated updates of TC centers.
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Journal articleToumi R, 2021,
100 Years of meteorology at Imperial College
, Weather, Vol: 76, Pages: 119-119, ISSN: 0043-1656 -
Journal articleHuang B, Myint KH, Wang Y, et al., 2021,
Cation-Dependent Interfacial Structures and Kinetics for Outer-Sphere Electron-Transfer Reactions
, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 125, Pages: 4397-4411, ISSN: 1932-7447- Cite
- Citations: 66
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Journal articleStreet OD, Crisan D, 2021,
Semi-martingale driven variational principles
, Proceedings of the Royal Society A Mathematical Physical and Engineering Sciences, Vol: 477, ISSN: 1364-5021Spearheaded by the recent efforts to derive stochastic geophysical fluid dynamics models, we present a general framework for introducing stochasticity into variational principles through the concept of a semi-martingale driven variational principle and constraining the component variables to be compatible with the driving semi-martingale. Within this framework and the corresponding choice of constraints, the Euler-Poincaré equation can be easily deduced. We show that the deterministic theory is a special case of this class of stochastic variational principles. Moreover, this is a natural framework that enables us to correctly characterize the pressure term in incompressible stochastic fluid models. Other general constraints can also be incorporated as long as they are compatible with the driving semi-martingale.
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Journal articleCudby J, Lefauve A, 2021,
Weakly nonlinear Holmboe waves
, PHYSICAL REVIEW FLUIDS, Vol: 6, ISSN: 2469-990X- Cite
- Citations: 5
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Journal articleCao XE, 2021,
Navigating My Way as a First-Generation Student
, Matter, Vol: 4, Pages: 332-335, ISSN: 2590-2393Underrepresented minorities in academia face many challenges: economic and social burden, exclusion, discrimination, and lack of access to information and mentoring. Here, Xiangkun Elvis Cao, a PhD candidate at Cornell University, shares his experience of successfully navigating his way through hardship from rural China as a first-generation college student to landing on Forbes 30 Under 30 for North America. He discusses the shared barriers for underrepresented groups and offers his insights for flourishing as a minority.
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Journal articleQuilodrán-Casas C, Silva VS, Arcucci R, et al., 2021,
Digital twins based on bidirectional LSTM and GAN for modelling COVID-19
The outbreak of the coronavirus disease 2019 (COVID-19) has now spreadthroughout the globe infecting over 100 million people and causing the death ofover 2.2 million people. Thus, there is an urgent need to study the dynamics ofepidemiological models to gain a better understanding of how such diseasesspread. While epidemiological models can be computationally expensive, recentadvances in machine learning techniques have given rise to neural networks withthe ability to learn and predict complex dynamics at reduced computationalcosts. Here we introduce two digital twins of a SEIRS model applied to anidealised town. The SEIRS model has been modified to take account of spatialvariation and, where possible, the model parameters are based on official virusspreading data from the UK. We compare predictions from a data-correctedBidirectional Long Short-Term Memory network and a predictive GenerativeAdversarial Network. The predictions given by these two frameworks are accuratewhen compared to the original SEIRS model data. Additionally, these frameworksare data-agnostic and could be applied to towns, idealised or real, in the UKor in other countries. Also, more compartments could be included in the SEIRSmodel, in order to study more realistic epidemiological behaviour.
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Journal articleSparks N, Toumi R, 2021,
On the seasonal and sub-seasonal factors influencing East China tropical cyclone landfall
, Atmospheric Science Letters, Vol: 22, Pages: 1-8, ISSN: 1530-261XTo date it has proved difficult to make seasonal forecasts of tropical cyclones, particularly for landfall and in East China specifically. This study examines sources of predictability for the number of landfalling typhoons in East China on seasonal (June–October) and sub‐seasonal time scales. East China landfall count is shown to be independent of basin‐scale properties of TC tracks, such the genesis location, duration, basin track direction and length, and basin total count. Large‐scale environmental climate indices which are potential basin scale drivers are also shown to be largely uncorrelated with landfall prior to and throughout the season. The most important factor is the steering in the final stages to landfall. The seasonal landfall is strongly anti‐correlated with the more local zonal mid‐tropospheric wind field over the East China sea (r = −.61, p < .001). It is proposed that geopotential height anomalies over Korea/Japan cause anomalous easterly winds in the East China Sea and enhance landfall rates by steering typhoons onto the coast. Early, peak, and late sub‐seasonal landfall counts are shown to be independent of each other yet share this predictor. This local feature may be dynamically predictable allowing a potential hybrid dynamical‐statistical seasonal forecast of landfall.
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Journal articleSechi S, Giarola S, Lanzini A, et al., 2021,
A bottom-up appraisal of the technically installable capacity ofbiogas-based solid oxide fuel cells for self power generation in wastewatertreatment plants
, Journal of Environmental Management, Vol: 279, Pages: 1-15, ISSN: 0301-4797This paper proposes a bottom-up method to estimate the technical capacity of solid oxide fuel cells to be installed in wastewater treatment plants and valorise the biogas obtained from the sludge through an efficient conversion into electricity and heat. The methodology uses stochastic optimisation on 200 biogas profile scenarios generated from industrial data and envisages a Pareto approach for an a posteriori assessment of the optimal number of generation unit for the most representative plant configuration sizes. The method ensures that the dominant role of biogas fluctuation is included in the market potential and guarantees that the utilization factor of the modules remains higher than 70% to justify the investment costs. Results show that the market potential for solid oxide fuel cells across Europe would lead up to 1,300 MW of installed electric capacity in the niche market of wastewater treatment and could initiate a capital and fixed costs reduction which could make the technology comparable with alternative combined heat and power solutions.
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Journal articleToumi R, Wang S, 2021,
Recent migration of tropical cyclones toward coasts
, Science, Vol: 371, Pages: 514-517, ISSN: 0036-8075Poleward migrations of tropical cyclones have been observed globally, but their impact on coastal areas remains unclear. We investigated the change in global tropical cyclone activity in coastal regions over the period 1982–2018. We found that the distance of tropical cyclone maximum intensity to land has decreased by about 30 kilometers per decade, and that the annual frequency of global tropical cyclones increases with proximity to land by about two additional cyclones per decade. Trend analysis reveals a robust migration of tropical cyclone activity toward coasts, concurrent with poleward migration of cyclone locations as well as a statistically significant westward shift. This zonal shift of tropical cyclone tracks may be mainly driven by global zonal changes in environmental steering flow.
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Journal articleZhang Y, Etzold MA, Lefauve A, 2021,
Growth of gas-filled penny-shaped cracks in decompressed hydrogels
, SOFT MATTER, Vol: 17, ISSN: 1744-683X- Cite
- Citations: 1
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ReportMitchell-Larson E, Green T, Lewis-Brown E, et al., 2021,
How can carbon offsetting help UK further and higher education institutions achieve net zero emissions?
, COP26 Universities Network Briefin, Publisher: COP26 Universities NetworkThere are a range of views on the use of carbonoffsetting among academics, higher and furthereducation professional staff, corporates andoffsetting providers. When and where offsets shouldbe used or not used, and what types of offsets to use,are to some extent value-laden choices. These choicesare being actively debated at the international andcommunity level. This briefing note provides guidance to support the development of further and highereducation offsetting policies and to challengeinstitutions, including our own. It specifically discussesthe use of offsetting in the context of net zerostrategies. We are also using the briefing to consultour institutions on the approaches they are taking.We hope it prompts discussion and collective actiontowards making net zero a reality.
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Journal articleRao RR, Stephens IEL, Durrant JR, 2021,
Understanding What Controls the Rate of Electrochemical Oxygen Evolution
, JOULE, Vol: 5, Pages: 16-18, ISSN: 2542-4351- Cite
- Citations: 23
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ReportKoberle A, Ostrovnaya A, Ganguly G, 2021,
A guide to building climate-financial scenarios for financial institutions
, A guide to building climate-financial scenarios for financial institutions, https://www.imperial.ac.uk/grantham/, Publisher: Grantham Institute, 35This briefing considers how the financial sector can manage the risks associated with moving to a zero-carbon future. The paper outlines why it is essential for financial institutions to understand so-called climate transition scenarios, which explore this journey to a zero-carbon future. The paper also sets out a framework that financial institutions can use to construct, or understand and use, climate transition scenarios in the context of financial sector risk management.
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Journal articleKonstantinoudis G, Padellini T, Bennett J, et al., 2021,
Long-term exposure to air-pollution and COVID-19 mortality in England: a hierarchical spatial analysis
, Environment International, Vol: 146, ISSN: 0160-4120Recent studies suggested a link between long-term exposure to air-pollution and COVID-19 mortality. However, due to their ecological design based on large spatial units, they neglect the strong localised air-pollution patterns, and potentially lead to inadequate confounding adjustment. We investigated the effect of long-term exposure to NO2 and PM2.5 on COVID-19 mortality in England using high geographical resolution. In this nationwide cross-sectional study in England, we included 38,573 COVID-19 deaths up to June 30, 2020 at the Lower Layer Super Output Area level (n = 32,844 small areas). We retrieved averaged NO2 and PM2.5 concentration during 2014–2018 from the Pollution Climate Mapping. We used Bayesian hierarchical models to quantify the effect of air-pollution while adjusting for a series of confounding and spatial autocorrelation. We find a 0.5% (95% credible interval: −0.2%, 1.2%) and 1.4% (95% CrI: −2.1%, 5.1%) increase in COVID-19 mortality risk for every 1 μg/m3 increase in NO2 and PM2.5 respectively, after adjusting for confounding and spatial autocorrelation. This corresponds to a posterior probability of a positive effect equal to 0.93 and 0.78 respectively. The spatial relative risk at LSOA level revealed strong patterns, similar for the different pollutants. This potentially captures the spread of the disease during the first wave of the epidemic. Our study provides some evidence of an effect of long-term NO2 exposure on COVID-19 mortality, while the effect of PM2.5 remains more uncertain.
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Journal articleOluleye G, Gandiglio M, Santarelli M, et al., 2021,
Pathways to commercialisation of biogas fuelled solid oxide fuel cells in European wastewater treatment plants
, Applied Energy, Vol: 282, ISSN: 0306-2619Fuel cell developments are driven by the need for more efficient and cleaner energy provision; however, current costs make it uneconomic in wastewater treatment plants. Interventions via policy instruments and business models may be required for cost reduction until the fuel cell is driven purely by market forces. In this work a novel market potential assessment methodology is developed and applied to quantify the impact of various interventions on biogas fuelled solid oxide fuel cell cost reduction and synthesize pathways to its commercialisation. The method is applied to 6181 plants in 27 European countries. Results show that 71% cost reduction is required for a medium sized fuel cell to be market driven. Existing incentives can trigger cost reduction by 13–38% but are not able to sustain it until the fuel cell is market driven. Innovations in business models, and incentivising business models instead of technologies can trigger and sustain cost reduction. Results also show that under today’s high capital cost, the number of economically attractive plants required to install fuel cells are lowest when business models are incentivised compared to other interventions. Incentivising new business models to encourage innovation in the sector has more impact that incentivising technologies. The framework is also relevant for creating narratives around the commercialisation of new technologies.
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Journal articleRao RR, Tulodziecki M, Han B, et al., 2021,
Reactivity with Water and Bulk Ruthenium Redox of Lithium Ruthenate in Basic Solutions
, ADVANCED FUNCTIONAL MATERIALS, Vol: 31, ISSN: 1616-301X- Cite
- Citations: 5
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Journal articleSmith M, Toumi R, 2021,
A dipole of tropical cyclone outgoing long-wave radiation
, Quarterly Journal of the Royal Meteorological Society, Vol: 147, Pages: 166-180, ISSN: 0035-9009Large‐scale (500 ≤ r ≤ 2,200 km) outgoing long‐wave radiation (OLR) and water vapour (WV) fields are investigated in satellite observations over the Pacific, linked to ERA‐5 reanalysis data and the ECMWF ensemble forecasts of tropical cyclones (TC) globally. A large‐scale OLR dipole pattern of low and high fluxes are found in both the observations and model. As expected, a low OLR region is positioned within the TC circulation, but there is also a robust high OLR region poleward and west of the TC centre. A dry “black hole” on WV grey‐scale imagery occupies the same region of high OLR. Relative to the central low OLR TC signal, the typical dipole magnitude, distance and orientation of the high OLR regions are 230 W·m−2, 1,150 km, and 145° anticlockwise from east. From the reanalysis we find that the interaction between the vortex and the environmental flows produces upper‐level convergence, low‐level divergence and subsidence throughout the troposphere in the region of high OLR. Analysis of the ECMWF model shows that the position of the high OLR region rotates anticlockwise about the TC centre as the TC moves from westward to eastward. Through use of a sub‐ensemble, we test if capturing the high OLR anomaly has a significant relationship with TC track. We apply a perfect model approach and find that sub‐ensembles that are composed of models whose large‐scale OLR fields closely match the target TC also have a better track. This improvement is mostly attributed to the high OLR component of the dipole.
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Journal articleElvis Cao X, Kaminer Y, Hong T, et al., 2020,
HI-Light: A Glass-Waveguide-Based "Shell-and-Tube" Photothermal Reactor Platform for Converting CO2 to Fuels.
, iScience, Vol: 23In this work, we introduce HI-Light, a surface-engineered glass-waveguide-based "shell-and-tube" type photothermal reactor which is both scalable in diameter and length. We examine the effect of temperature, light irradiation, and residence time on its photo-thermocatalytic performance for CO2 hydrogenation to form CO, with a cubic phase defect-laden indium oxide, In2O3-x(OH)y, catalyst. We demonstrate the light enhancement effect under a variety of reaction conditions. Notably, the light-on performance for the cubic nanocrystal photocatalyst exhibits a CO evolution rate at 15.40 mmol gcat -1 hr-1 at 300°C and atmospheric pressure. This is 20 times higher conversion rate per unit catalyst mass per unit time beyond previously reported In2O3-x(OH)y catalyst in the cubic form under comparable operation conditions and more than 5 times higher than that of its rhombohedral polymorph. This result underscores that improvement in photo-thermocatalytic reactor design enables uniform light distribution and better reactant/catalyst mixing, thus significantly improving catalyst utilization.
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