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Optimizing the temperature sensitivity of the isoprene emission model MEGAN in different ecosystems using a Metropolis‐Hastings Markov Chain Monte Carlo method
Get PDFIsoprene is a reactive hydrocarbon emitted to the atmosphere in large quantities by terrestrial vegetation. Annual total isoprene emissions exceed 300 Tg a−1, but emission rates vary widely among plant species and are sensitive to meteorological and environmental conditions including temperature, sunlight, and soil moisture. Due to its high reactivity, isoprene has a large impact on air quality and climate pollutants such as ozone and aerosols. It is also an important sink for the hydroxyl radical which impacts the lifetime of the important greenhouse gas methane along with many other trace gas species. Modeling the impacts of isoprene emissions on atmospheric chemistry and climate requires accurate isoprene emission estimates. These can be obtained using the empirical Model of Emissions of Gases and Aerosols from Nature (MEGAN), but the parameterization of this model is uncertain due in part to limited field observations. In this study, we use ground‐based measurements of isoprene concentrations and fluxes from 11 field sites to assess the variability of the isoprene emission temperature response across ecosystems. We then use these observations in a Metropolis‐Hastings Markov Chain Monte Carlo (MHMCMC) data assimilation framework to optimize the MEGAN temperature response function. We find that the performance of MEGAN can be significantly improved at several high‐latitude field sites by increasing the modeled sensitivity of isoprene emissions to past temperatures. At some sites, the optimized model was nearly four times more sensitive to temperature than the unoptimized model. This has implications for air quality modeling in a warming climate.Canadian Space Agency; 16SUASEMIS, Natural Environment Research Council; NE/W003694/1, Federal Ministry of Education and Research; 01LB1001A, Ministério da Ciência, Tecnologia e Inovação; 01.11.01248.00, Research Council of Finland; 310682, 337550, 346371, 357905, Ministry of Science, Innovation and Universities; RYC2020‐029216‐I, PID2021‐122892NA‐I00Journal of Geophysical Research: Biogeoscience
Biogeochemical dynamics of major elements in municipal solid waste landfills can induce health risks for nearly 1 billion people
Get PDFLandfills remain the primary method for managing over a billion tonnes of municipal solid waste (MSW) every year worldwide. Landfills, meanwhile, cause various environmental issues that also threaten human health. However, complex biogeochemical conditions in landfills hinder the understanding of the long-term fates of disposed elements, limiting assessments and mitigations of environmental and health risks. In this review, we synthesized 2,387 data points from 754 studies to quantify landfill elemental dynamics. The results reveal that ∼20% of carbon, 99%) alongside remaining elements persist in solid. Approximately 14% of the global population faces high exposure to fugitive landfill gas and leachate emissions, particularly in the Global South. These findings fill a critical knowledge gap and highlight the need for targeted remediation to mitigate environmental and health impacts from landfills.National Environment Agency: USS-IF-2021-4, National Environment Agency: CTRL-2025-1D-01F.C., K.Y., and X.F. are partially supported by the National Research Foundation, Singapore, and the National Environment Agency, Singapore under its Closing the Waste Loop Funding Initiative (Award No. USS-IF-2021-4).One Eart
Can the physical‐hydraulic properties of degraded soil be improved using polymers?
No full textFor a degraded soil it is assumed that improvements in key physical-hydraulic properties occur at an optimum superabsorbent polymer (SAP) application rate, following repeated wetting and drying cycles. A column experiment was carried out in a shade house (Ceará State, Brazil), following a completely randomized design, in a 6 × 4 factorial scheme in which six SAP application rates (0—control, 0.15, 0.30, 0.60, 1.20, and 2.40 g kg−1) were incorporated into a sandy loam soil and subjected to four numbers of wetting and drying cycles (one, three, six, and nine cycles), with three replications. Soil bulk density, total porosity, macroporosity and microporosity, degree of flocculation, plant available water, and pore distribution by size were evaluated. After six wetting and drying cycles, the highest SAP rate reduced soil bulk density by 4%–9% compared to the control. At an SAP application rate of 1.2 g kg−1 the degree of flocculation increased by 25%, mainly after six wet and drying cycles. From the rate of 0.15 g kg−1 SAP onward, there was a 20% reduction in macroporosity and a 28% increase in microporosity, increasing total porosity, particularly after six cycles. SAP rates ranging from 0.15 to 0.6 g kg−1 increased available water by 12%–33%, while the highest polymer rate increased available water by 40%–50% compared to the control. This increase in soil available water is of strategic importance for water use efficiency, crop yields, and restoration activities in degraded dryland sandy soils.National Council for Scientific and Technological Development, Grant/Award Number: 305907/2019-0Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil, Grant/Award Number: Finance Code 001Soil Science Society of America Journa
Insights from a specialist NATO meeting, AVT-394: advancing environmental sustainability in military training
No full textThe NATO specialist meeting, AVT-394, held in Koblenz, Germany in October 2024, gathered experts from NATO countries, including Canada, Germany, the UK, Finland, Denmark, Switzerland and the USA, to evaluate advancements in water sampling, monitoring, and remediation techniques aimed at mitigating munitions-related contamination in live-firing ranges. As a current PhD student at the UK Defence Academy, Cranfield University, funded by Cranfield University and the Ministry of Defence and Cranfield University under the CBRN educational program and supervised by Professor Tracey Temple and Professor Frederic Coulon, I had the opportunity to attend and present at the specialist meeting. My research focuses on representative sampling methods for hazardous chemicals released by industry, warfare or terrorist acts. My background in Forensic science and analysis has enabled me to build a broad scientific basis, thus aiding me in understanding diverse scientific approaches. Presenting a paper on my current research explaining the importance of a well thought through sampling plan
for post-blast water sampling, was a great and invaluable experience. This opportunity allowed me to network with experienced industry peers and engage in valuable knowledge exchange.Explosives Engineerin
The impact of columnar and equiaxed β-grain structures on mechanical anisotropy in high-deposition-rate additively manufactured α + β titanium alloys
Get PDFThere is growing interest to produce α + β titanium alloys with high-deposition-rate additive manufacturing (DED-AM) processes for aerospace applications. However, there are still important aspects of their microstructure-mechanical property relationships that are not well understood, which are linked to the macro and microstructure heterogeneities generated by the AM processes and intrinsic titanium metallurgy that produce columnar β-grain structures. Trends in the literature, which are based primarily on Ti-6Al-4V data, have shown mechanical anisotropy is often present when samples exhibit coarse and columnar β-grain structures. This includes yield-stress and elongation anisotropy arising during uniaxial tensile testing, and crack growth rate anisotropy with high scatter recorded during fatigue testing, both of which are generally only tested in orientations parallel and perpendicular to the AM build direction. In this work, this mechanical anisotropy in α + β titanium alloys is investigated in more detail with Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo-0.1Si wire-arc additively manufactured test samples, comparing columnar parent β-grain structures to equiaxed grain structures. In particular, highlighting that the true yield-stress anisotropy in columnar grain samples is only revealed when testing the material at a 45 deg orientation away from the AM build direction. It is also shown that the large grain boundary α colonies that form on parent columnar β-grain boundaries have a significant impact on the fatigue crack growth rate data scatter. Refining the parent β-grain structures is demonstrated to resolve these issues and the related microstructure mechanisms were investigated in detail, using both experimental and crystal plasticity simulation methods. Finally, the formation and three dimensionality of the detrimental grain boundary α colonies that nucleate on columnar β-grain boundaries were investigated for the first time using in-situ SEM heating and 3D-EBSD techniques.The authors are appreciative of the EPSRC program grants NEWAM (EP/R027218/1) and LightForm (EP/R001715/1) for supporting aspects of this research.The authors acknowledge the use of equipment associated with the Advanced Metals Processing and Characterisation themes of the Henry Royce Institute for Advanced Materials, funded through EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1, and EP/P025498/1.Metallurgical and Materials Transactions
Exploiting cognition in ISAR processing for spectral compatibility applications
Get PDFThis article introduces and analyzes the concept of a cognitive inverse synthetic aperture radar (ISAR) ensuring spectral compatibility in crowded electromagnetic environments. In such a context, the proposed approach alternates between environmental perception, recognizing possible emitters in its frequency range, and an action stage, synthesizing and transmitting a tailored radar waveform to achieve the desired imaging task while guaranteeing spectral coexistence with overlaid emitters. The perception is carried out by a spectrum sensing module providing the true relevant spectral parameters of the sources in the environment. The action stage employs a tailored signal design process, synthesizing a radar waveform with bespoke spectral notches, enabling ISAR imaging over a wide spectral bandwidth without interfering with other radio frequency (RF) sources. A key enabling requirement for the proposed application is the capability to successfully recover possible missing data in the frequency domain (induced by spectral notches) and in the slow-time dimension (enabling concurrent RF activities still in a cognitive fashion). This process is carried out by resorting to advanced methods based on either the compressed-sensing framework or a rank-minimization (RM) recovery strategy. The capabilities of the proposed system are assessed by exploiting a dataset of drone measurements in the frequency band between 13 and 15 GHz. Results highlight the effectiveness of the devised architecture to enable spectral compatibility while delivering high-quality ISAR images as well as additional RF activities.The work of Massimo Rosamilia, Augusto Aubry, and Antonio De Maio was supported in part by the European Union under the Italian National Recovery and Resilience Plan (NRRP) of NextGenerationEU, partnership on “Telecommunications of the Future” (PE00000001-program “RESTART”)IEEE Transactions on Radar System
Evolution and application of dimensional metrology: a comparative review
Get PDFMetrology, the science of measurement, has significantly evolved to meet the demands of modern industries. This paper explores the historical significance, technological advancements, and contemporary applications of metrology, highlighting key technologies like laser trackers, photogrammetry, interferometers, optical fibres, coordinate measuring machines (CMM), coordinate measuring Arms (CMA), electromagnetic distance measurement (EDM), and digital metrology tools. Each technology’s unique capabilities, such as high precision, long-range measurement, and data integration, are compared, emphasizing their roles in fields like aerospace and manufacturing. The comparative analysis provides insights into the advantages and limitations of these technologies, offering guidance for selecting appropriate metrology solutions. Additionally, the potential future advancements in metrology, driven by innovations in sensor technology, artificial intelligence, and digital twins, are discussed. This paper accentuates metrology’s pivotal role in enhancing measurement accuracy, reliability, and efficiency in various engineering and manufacturing processes.International Journal of Computer Integrated Manufacturin
Comparative analysis of multi-link selection strategies for next-generation aeronautical communications
Get PDFNext-generation aviation demands seamless connectivity across heterogeneous networks, yet maintaining uninterrupted links under strict performance requirements remains a major challenge. Current Aeronautical Telecommunication Network (ATN) mechanisms depend on static tables that overlook airframe shadowing and dynamic flight conditions, limiting their effectiveness in complex radio environments. This paper delivers a comprehensive evaluation of terrestrial and non-Terrestrial networks (NTN) and benchmarks twelve link-selection algorithms across representative Air-To-Satellite (A2Sat) and Air-To-Ground (A2G) scenarios. The system design introduces an AI-driven dual-layer onboard controller that integrates predictive planning with real-Time adaptation. Simulation results show that this approach enables proactive link switching, enhances stability, and supports efficient flight operations. To sum up, this work can be a roadmap for ATN architectures by delivering resilient, hyper-connected communications required for next-generation aviation and paves the way for this implementation.Thales under iCASE EPSRC Programme (Grant Number: 2924183)IEEE Acces
A review of acoustic metamaterials for electrical devices reliability: a reliability-oriented design perspective
Get PDFModern electronic systems increasingly operate in harsh environments where vibration, thermal cycling, and electromagnetic interference (EMI) jointly threaten their long-term reliability. Acoustic metamaterials (AMMs), with their ability to manipulate wave propagation through engineered subwavelength structures, offer a promising pathway toward mitigating these reliability risks. This review provides a comprehensive overview of AMMs from a reliability-oriented design (ROD) perspective. The proposed ROD framework systematically maps environmental stressors to failure mechanisms and corresponding AMM strategies, thereby bridging the gap between material innovation and reliability assurance. Core AMM mechanisms—including local resonance, Bragg scattering, and cavity absorption—are analyzed alongside emerging multifunctional designs that integrate mechanical, thermal, and electromagnetic functions. Representative applications in MEMS, RF resonators, vehicular electronics, and data-center cooling systems demonstrate the practical benefits of AMMs in suppressing failure-inducing stressors, while emerging applications such as voice security and wearable devices are also introduced. The discussion section addresses persistent challenges in multifunctional coupling, scale incompatibility, manufacturing constraints, and the need for reliable integration across multiple physical domains, while also highlighting emerging trends in intelligent design facilitated by artificial intelligent (AI) integration. This review links material-level innovation and system-level reliability, offering a new paradigm for embedding AMMs into next-generation resilient electronic systems.Applied Materials Toda
Cross-national radiomics validation using mammography to predict occult invasion in ductal carcinoma in situ
Get PDFBackground:
Patients diagnosed with ductal carcinoma in situ (DCIS) may also have undetected invasive breast cancer. Radiomic features of calcifications at mammography can predict occult invasive disease among women diagnosed with DCIS at core-needle biopsy, which could affect treatment recommendations. However, the generalizability of these radiomic models must be tested before they are adopted in clinical practice.
Purpose:
To evaluate the generalizability of radiomic models based on mammography features to predict occult invasive cancer among women diagnosed with DCIS at core-needle biopsy from three national datasets.
Materials and Methods:
In this retrospective, cross-national study, digital mammograms from women diagnosed with DCIS at breast core-needle biopsy were collected in the United States, United Kingdom, and the Netherlands between January 1, 2000, and December 31, 2021. Only asymptomatic women who had calcifications but did not have associated masses, architectural distortions, or asymmetries were included. Radiomic models were developed using cross-validated logistic regression on each national dataset, then round-robin tested on the other datasets. Differences across the three datasets in terms of the upstaging rate, age, lesion size, and estrogen and progesterone receptor levels were assessed using Kruskal-Wallis or χ2 test.
Results:
The study included 1498 women (age range, 31–89 years; mean age, 59 years ± 9 [SD]), as follows: 696 women from the United States, 618 women from the United Kingdom, and 184 women from the Netherlands, with upstaging rates of 16.1%, 16.7%, and 14.1%, respectively. Internal cross-validation areas under the receiver operating characteristic curve (AUCs) were 0.675 (95% CI: 0.671, 0.679), 0.603 (95% CI: 0.567, 0.722), and 0.701 (95% CI: 0.697, 0.706) for the U.S., UK, and Netherlands datasets, respectively. The model that was trained on the U.S. dataset yielded cross-national validation AUCs of 0.604 (95% CI: 0.560, 0.648) and 0.682 (95% CI: 0.607, 0.757) for the UK and Netherlands datasets.
Conclusion:
Radiomic machine learning models were shown to have the potential to predict occult invasive cancer in women with DCIS across diverse settings.National Cancer InstituteRadiolog