Staff publications (SWEE)

Permanent URI for this collection

https://dspace.lib.cranfield.ac.uk/handle/1826/8743

Browse

Now showing 1 - 20 of 3055

Open Access
Understanding the difference between the nano and micro bubble size distributions generated by a regenerative turbine microbubble generator using ozone
(Elsevier, 2025-02-01) John, Alexander; Brookes, Adam; Carra, Irene; Jefferson, Bruce; Jarvis, Peter
There is a genuine paucity of data concerning the relative significance of the nano and the microbubble size distributions that are collectively generated when operating microbubble generation devices. Accordingly, the current work aimed to address this knowledge gap by measuring the two size distributions generated by a regenerative turbine microbubble generator using ozone and assess the relative significance of the nanobubble fraction. The microbubble fraction was measured with a focus-beam reflectance measurement device and the nanobubble fraction with a nano particle tracking instrument. The latter was calibrated using latex spheres to understand method uncertainty and to optimise the measurement approach. Sauter mean diameters of 217 nm and 37 μm were reported for the nano and microbubble fractions, respectively, with half of the microbubbles being <5000 nm in size. A comparison of the size and number concentrations of the different bubble types revealed that the majority of the gas was contained within the microbubble fraction, and hence, this controlled the overall mass transfer performance of the system. Further, the nanobubbles were observed to be stable for 18 h with little change in their size or number, indicating there was no net transfer of their gaseous contents. Overall, the work revealed that when considering enhancing gas-liquid mass transfer processes with micro-nano bubble generators, the microbubble fraction is key.
Open Access
Editorial: Scientific advances in river restoration
(Wiley, 2025-01) Prady, Jane; Austin, Sam; Dodd, Jennifer; White, James; Wilkes, Martin; Naura, Marc
In September 2023, the River Restoration Centre (RRC) hosted the inaugural Scientific Advances in River Restoration (SARR) conference in collaboration with the University of Liverpool, UK. As we confront the twin crises of climate change and biodiversity loss, this event underscored the importance of global collaboration among river restoration scientists to help inform evidence‐led solutions. Fluvial systems are particularly vulnerable to global climatic pressures, with droughts and floods exacerbating the impacts of human‐induced river modifications. River restoration is a crucial tool in addressing these pervasive challenges, capable of benefiting both people (e.g., flood mitigation, community engagement) and nature (e.g., ecological recovery, ecosystem functionality). The SARR conference aimed to unite scientists from various disciplines and countries, foster collaborations, and highlight new advancements to enhance global progress in river restoration science. This river restoration special issue features a diverse selection of papers presented at the SARR conference, showcasing the multidisciplinary nature of contemporary river restoration.
Open Access
The untargeted metabolomic analysis of Ammodaucus leucotrichus Coss. & Dur. seeds reveals previously undescribed polar lignans and terpenoids
(Elsevier, 2025-02-01) Kisiriko, Musa; Bitchagno, Gabin T. M.; Noleto-Dias, Clarice; Naboulsi, Imane; Anastasiadi, Maria; Terry, Leon A.; Sobeh, Mansour; Beale, Michael H.; Ward, Jane L.
The polar metabolome of the medicinal plant Ammodaucus leucotrichus Coss. & Dur. has not been comprehensively characterised. In this study, the chemical composition of a water/methanol (4:1) extract of seeds was determined through a combination of UHPLC-MS and NMR techniques. Sixty compounds were identified from the extract with 36 of these confirmed using UHPLC-MS and/or NMR data while the remaining 24 were given putative identifications based on UHPLC-MS data. The compounds included lignans, terpenes, phenolics, flavonoids, and alkaloid derivatives together with some amino- and organic acids. Of these 2 terpenoids and 3 lignans were found to be novel and were isolated and structures determined by comprehensive NMR studies. A further novel lignan glycoside was tentatively identified. Together these data represent the most comprehensive profile of this traditional medicinal plant, providing an annotated profile that can form the basis of future correlative metabolomic investigations to determine active principles behind its reported bioactivities.
Open Access
Toxicity, bioaccumulation and mitigating strategies of heavy metals stress on morpho-physiology of spinach
(Springer, 2024-12-31) Bibi, Ayesha; Rasul, Fahd; Shahzad, Sobia; Sakrabani, Ruben; Din, Wasi ud; Mckenna, Patrick; Sajid, Muhmmad
The purpose of this review was to look into the different ways that heavy metal stress affects spinach, and how hazardous they are to soil, people's health, and plant ecosystems. Heavy metals in soil are caused by anthropogenic and industrial activity, and when they accumulate in food chains, they pose a major risk to human health. This paper presents an overview of heavy metals' negative impacts on soil fertility, plant physiology, and human health. Using spinach as a model plant, it is simple to cultivate and maintain, making it a diverse choice for studying how plants respond to stresses such as heavy metals. They describe how heavy metal stress affects spinach morphology and physiology, including absorption, detoxification, and translocation throughout the plant system. Understanding these procedures is critical when assessing the potential risks associated with the accumulation of hazardous components in spinach's edible parts. This review investigates the impact of heavy metal stress on the nutritional quality and yield of spinach after metal exposure. It is critical to investigate numerous strategies for reducing heavy metal stress in spinach, including soil remediation approaches, phytoremediation capabilities, and genetic procedures aimed to increase plant resistance to metals. The goal of this overview is to shed light on the mechanisms underlying the effects of heavy metals on spinach and to propose strategies to alleviate them, thereby protecting agricultural sustainability and public health (Fig. 1).
Open Access
Numerical study on the combustion and emissions characteristics of liquid ammonia spray ignited by dimethyl ether spray
(MDPI, 2024-12-31) Leng, Yupeng; Dai, Liming; Wang, Qian; Lu, Jiayu; Yu, Ouqing; Simms, Nigel John
Ammonia has attracted considerable attention as a zero-carbon fuel for decarbonizing energy-intensive industries. However, its low reactivity and narrow flammability limit efficient ignition and efficient combustion. By using CONVERGR software, this study numerically investigates the ignition and combustion characteristics of liquid ammonia spray ignited by dimethyl ether spray in a constant-volume chamber at an ambient temperature of 900 K. Critical parameters, including injection angles (90°–150°), liquid ammonia injection pressures (60–90 MPa), and ambient pressures (2.8–5.8 MPa), were systematically analyzed to evaluate their effects on ignition conditions and emissions. Results indicate that increasing the injection angle improves mixing between liquid ammonia and dimethyl ether sprays, enhancing combustion efficiency and achieving a maximum efficiency of 92.47% at 120°. Excessively large angles cause incomplete combustion or misfire. Higher liquid ammonia injection pressures improve atomization and promote earlier interactions between the sprays but reduce combustion efficiency, decreasing by approximately 2% as injection pressure increases from 60 MPa to 90 MPa. Higher ambient pressures improve combustion stability but decrease ammonia combustion efficiency. Post-combustion NO emissions at 5.8 MPa are reduced by 60.48% compared to 3.8 MPa. The formation of NO is strongly correlated with the combustion efficiency of liquid ammonia. A higher combustion rate of liquid ammonia tends to result in elevated NO. Based on these findings, an injection angle of 120°, an NH3 injection pressure of 75 MPa, and an ambient pressure of 3.8 MPa are recommended to optimize combustion efficiency.
Open Access
Editorial: Micro/nano devices and technologies for neural science and medical applications
(Frontiers, 2025-01-06) Liu, Juntao; Yang, Zhugen; Wang, Yang; Wang, Li; Li, Ziyue
Research on micro/nano devices and technologies represents a significant Frontier at the intersection of information science and life sciences, holding substantial strategic importance and promising application prospects in the fields of neural science and medical applications (Liu et al., 2020). With the rapid advancement of micro/nano processing technology, innovative intelligent, miniaturized, and integrated devices are emerging. These devices offer distinct advantages in detection and regulation. Notably, integrating micro/nano devices with neural science and clinical medicine can address scientific frontiers while fostering new research hotspots.
Open Access
Climate change impacts on shoreline migration and community livelihood resilience: evidence from coastal Bangladesh
(Frontiers, 2024) Islam, Md Tariqul; Hossain, Md Monabbir; Ha-Mim, Nur Mohammad; Hossain, Md Zakir; Sikder, Sujit Kumar
The livelihoods of coastal people are at risk as shoreline migration is accelerated by climate change. To safeguard these communities and maintain their economy, it is imperative to strengthen resilience via adaptive strategies. Therefore, this study aims to estimate the rates and impacts of physical shoreline migration over the past 9,000 years using geospatial analysis and focus on understanding the livelihood resilience of coastal at-risk communities using in-depth interviews with environmental experts. The dynamic system of the Ganga-Brahmaputra-Meghna is highly complex and causes continuous shoreline migration. Historical data and more recent satellite remote sensing imagery analysis identified that the shrinking of the delta system has resulted from the migration of the shorelines at the mouth of the river system. Since 5,000 BP, it has been expanding towards the Bay of Bengal – meaning land gains at the coast. Land gain provides an opportunity for the extension of coastal communities but also increases their vulnerability to natural hazards. Moreover, by 2050, the salinity isoline with a 5-ppt is expected to shift inland by ⁓8 km in the south-east (Bhola-Patuakhali) and ⁓24 km in the southwest (Khulna-Satkhira) region. The in-depth interviews reveal several adaptive practices to effectively deal with the situation, including community knowledge, stakeholder engagement, local-led adaptation, and most importantly, temporal migration. The findings also highlighted the urgent need for an adaptation plan for the sustainability and resilience of coastal communities, considering indigenous knowledge with local cultural orientation and incorporation of scientific standards.
Open Access
Blue hydrogen production through partial oxidation: a techno‐economic and life cycle assessment
(Wiley, 2024) Khallaghi, Navid; Ghiami, Shamsoddin; Jeswani, Harish; Nabavi, Seyed Ali; Anthony, Edward J; Klyamkin, Semen
Partial oxidation (POx) as a hydrogen production method has not received comprehensive exploration as the resulting syngas has a relatively low H2/CO ratio compared to established techniques like steam methane reforming (SMR). As a result, this study aims to comprehensively investigate the feasibility of a low‐carbon hydrogen production process using POx from both technical‐economic and environmental standpoints. To achieve this, the Aspen Plus® software is employed to model a hydrogen production plant with carbon capture integration, referred to as POx‐CCS (carbon capture and storage). The research reveals that the overall energy efficiency of the POx‐CCS process is around 73%. Moreover, the economic evaluation indicates that the levelised cost of hydrogen (LCOH) is €1.8/ kgH2, given a fuel price of €5.7 per GJ. This cost competitiveness positions POx‐CCS in line with conventional hydrogen production methods. From an environmental perspective, the impact of climate change on hydrogen production through the POx‐CCS process is assessed to be 1.1 kg CO2 eq./kgH2. This impact is reduced by 69% compared to SMR with CCS.
Open Access
The soil microbial methylome: a tool to explore the role of epigenetic memory in driving soil abiotic legacy effects
(Elsevier, 2025-03) Sizmur, Tom; Larionov, Alexey
Epigenetics is a phenomenon whereby a stable hereditable change in gene expression can occur without changing the DNA sequence. DNA methylation (the addition of a methyl group to specific nucleotides in specific DNA motifs) is the most studied epigenetic mechanism and is widely observed in both eukaryotic and prokaryotic cells. We hypothesise that the soil methylome may play an important role in the manifestation of soil abiotic legacy effects, whereby temporary exposure of soil microbial communities to particular environmental conditions influences future soil microbial function. These abiotic legacy effects are important because they underpin the delivery of key ecosystem services in response to global environmental change. Third generation long-read sequencing technologies, such as Pacific Bioscience Single-Molecule Real-Time sequencing (SMRT-seq) and Oxford Nanopore sequencing provide an opportunity to study methylome heterogeneity in complex microbial communities. The simultaneous measurement of epigenetic, transcriptional, and microbial community composition changes may lead to the development of biomarkers of historic environmental stress and a greater understanding of the role of the soil methylome in the resilience of soil microbial communities to future environmental perturbations. It is therefore timely to add the meta-epigenetic layer to the multi-omics analysis of the soil microbiome to advance our understanding of soil abiotic legacy effects.
Open Access
Mapping variability of mycotoxins in individual oat kernels from batch samples: implications for sampling and food safety
(MDPI, 2025-01-11) Teixido-Orries, Irene; Molino, Francisco; Castro-Criado, Bianca; Jodkowska, Monika; Medina, Angel; Marín, Sonia; Verheecke-Vaessen, Carol
Oats are susceptible to contamination by Fusarium mycotoxins, including deoxynivalenol (DON), zearalenone (ZEN), and T-2/HT-2 toxins, posing food safety risks. This study analyses the variation in levels of 14 mycotoxins in 200 individual oat kernels from two DON-contaminated batch samples (mean = 3498 µg/kg) using LC-MS/MS. The samples also contained deoxynivalenol-3-glucoside (DON-3G), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), and ZEN. Contamination levels varied notably among individual kernels, with DON detected in 70% of them, followed by DON-3G (24.5%) and 3-ADON (20.5%). Importantly, 8% of kernels exceeded the EU legal limit for DON (1750 µg/kg), and some occasionally surpassed limits for ZEN and T-2/HT-2. Correlation analyses revealed strong associations between DON and its derivatives but weaker correlations with other toxins. Mycotoxin ratios varied widely, indicating that although they often co-occur, their concentrations differ between kernels. Contamination did not significantly impact kernel weight, though a slight trend toward lower weights in contaminated kernels was noted. Additionally, sampling statistics showed that as the percentage of selected kernels increased, the probability of batch sample rejection for DON contamination rose significantly. The study highlights the heterogeneity of mycotoxin contamination in oat batches, emphasising the importance of accurate detection and regulatory compliance to ensure safer oat-based products.
Open Access
Exploiting the potential of spherical PAM antenna for enhanced CRISPR-Cas12a: a paradigm shift toward a universal amplification-free nucleic acid test platform
(American Chemical Society, 2025-01-09) Dai, Jiahui; Wu, Beibei; Ai, Fengxiang; Yang, Zhugen; Lu, Yanyan; Zinian, Cai; Zeng, Kun; Zhang, Zhen
The CRISPR-Cas12a system has shown tremendous potential for developing efficient biosensors. Albeit important, current CRISPR-Cas system-based diagnostic technologies (CRISPR-DX) highly rely on an additional preamplification procedure to obtain high sensitivity, inevitably leading to issues such as complicated assay workflow, cross-contamination, etc. Herein, a spherical protospacer-adjacent motif (PAM)-antenna-enhanced CRISPR-Cas12a system is fabricated for universal amplification-free nucleic acid detection with a detection limit of subfemtomolar. Meanwhile, the clinical detection capability of this sensor was further verified using gold-standard real-time quantitative polymerase chain reaction through Mycobacterium tuberculosis measurement, which demonstrated its good reliability for practical applications. Importantly, its excellent sensitivity is mainly ascribed to high efficiency of target search induced by a localized PAM-enriched microenvironment and improved catalytic activity of Cas12a (up to 4 folds). Our strategy provides some new insights for rapid and sensitive detection of nucleic acids in an amplification-free fashion.
Open Access
Advancing two-phase wet gas flow measurement with Coriolis meters: optimal sensor orientation and a new model development
(Elsevier, 2025-03-01) Salehi, Seyed Milad; Lao, Liyun; Simms, Nigel; Drahm, Wolfgang; Lin, Yaoying; Rieder, Alfred; Güttler, Andreas
In this study, a novel wet gas model was developed based on the internal parameter of a Coriolis prototype to measure two-phase wet gas flow. Additionally, an optimal orientation of the Coriolis sensor was proposed to address challenges in the horizontal wet gas flow. Two Coriolis prototypes– one with a long-bent flow tubes (Type A), and another with short-bent flow tubes (Type B) – were employed to conduct tests in both vertical upward and horizontal pipelines. Different sensor axial angles (0, 40, 90, and 180°) were selected for testing in the horizontal section. Among different orientations (angles), it was found that the 40-degree angle outperforms the other installations in terms of the response proximity and over-reading of gas flow (OR). To understanding the impact of flow pattern on the response, a detailed analysis of different flow patterns in the wet gas was considered. A new correlation was developed between the damping factor of the Coriolis and both XLM and the total mass flow rate, leading to the proposal of a new wet gas model to predict gas and liquid flow rates with acceptable accuracy. In scenarios involving higher Froude numbers and annular flow patterns, which are more likely to occur, the Mean Absolute Percentage Error (MAPE) for the entire range of wetness (0 < XLM < 0.3) is 3.9 % for gas flow rate and 4.3 % for liquid flow rate with an uncertainty of 2.7 %.
Open Access
Portable microfluidic devices for monitoring antibiotic resistance genes in wastewater
(Springer, 2025-01-31) Feng, Rida; Mao, Kang; Zhang, Hua; Zhu, Hongxiang; Du, Wei; Yang, Zhugen; Wang, Shuangfei
Antibiotic resistance genes (ARGs) pose serious threats to environmental and public health, and monitoring ARGs in wastewater is a growing need because wastewater is an important source. Microfluidic devices can integrate basic functional units involved in sample assays on a small chip, through the precise control and manipulation of micro/nanofluids in micro/nanoscale spaces, demonstrating the great potential of ARGs detection in wastewater. Here, we (1) summarize the state of the art in microfluidics for recognizing ARGs, (2) determine the strengths and weaknesses of portable microfluidic chips, and (3) assess the potential of portable microfluidic chips to detect ARGs in wastewater. Isothermal nucleic acid amplification and CRISPR/Cas are two commonly used identification elements for the microfluidic detection of ARGs. The former has better sensitivity due to amplification, but false positives due to inappropriate primer design and contamination; the latter has better specificity. The combination of the two can achieve complementarity to a certain extent. Compared with traditional microfluidic chips, low-cost and biocompatible paper-based microfluidics is a very attractive test for ARGs, whose fluid flow in paper does not require external force, but it is weaker in terms of repeatability and high-throughput detection. Due to that only a handful of portable microfluidics detect ARGs in wastewater, fabricating high-throughput microfluidic chips, developing and optimizing recognition techniques for the highly selective and sensitive identification and quantification of a wide range of ARGs in complex wastewater matrices are needed.
Open Access
Combined oven/freeze drying as a cost and energy-efficient drying method for preserving quality attributes and volatile compounds of carrot slices
(Frontiers, 2025-01-09) Mina, Zobabalo Progress; Kaseke, Tafadzwa; Fadiji, Tobi; Silue, Yardjouma; Fawole, Olaniyi Amos
Introduction An effective and efficient drying method for preserving fresh carrots is essential in food processing. Combined drying represents a novel approach that addresses the shortcomings of conventional methods by balancing energy consumption, cost, and product quality. Methods This study evaluated the impact of combining oven drying (OD) with freeze-drying (FD) on drying behavior, energy requirements, costs, enzyme activity, and the physicochemical and sensory properties of dried carrots. Drying conditions included 36 hours of FD, OD, and combinations of OD and FD at 1 h of OD + 21 h of FD (OD1-FD21), 2 h of OD + 18 h of FD (OD2-FD18), 3 h of OD + 15 h of FD (OD3-FD15), and 9 h of OD. Results and discussion Compared to FD alone, the OD-FD combination reduced drying time by 39–50% and decreased energy consumption and costs by 40–56%. FD and OD-FD reduced polyphenol oxidase activity by 71–85% and peroxidase activity by 29–52% compared to OD alone. FD carrot slices retained significantly higher levels of β-carotene (11.67–25.96 mg/100 g DM), lycopene (9.91–21.85 mg/100 g DM), total phenolic content (7.12–10.24 mg GAE/100 g DM), and DPPH radical scavenging activity (16.44–19.38 mM AAE/100 g DM) than OD and OD-FD slices. OD-FD slices exhibited the highest levels of volatile compounds, including aldehydes, terpenes, esters, alcohols, ketones, and acids, indicating superior flavor preservation. Conclusion The OD2-FD18 combination emerged as the optimal method, significantly reducing energy consumption and costs while maintaining better β-carotene, total phenolic content, DPPH radical scavenging activity, and volatile compound profiles. This study highlights the potential of combined drying methods to enhance drying efficiency and product quality.
Open Access
Where are we with gender parity in academia and professional societies? A multinational look at women in soil science
(Wiley, 2025-01-01) Brevik, Eric C.; Krzic, Maja; Elbasiouny, Heba; Dawson, Lorna; Hannam, Jacqueline A.; Mbila, Monday; Reyes‐Sánchez, Laura Bertha; Coles, Natalie
Issues of diversity, equity and inclusion (DEI), including gender equity, have gained increasing recognition at the beginning of the 21st century. As an academic discipline, soil science has been late in addressing gender equity, but several peer‐reviewed studies have been published in the last 5 years. This study investigated gender equity in the soil science university faculty/academic staff (f/as) and soil professional societies in Canada, Egypt, Mexico, Nigeria, the United Kingdom and the United States of America (USA) using data publicly available on the Internet and anonymized data from soil science professional societies. We found that women still lagged behind men among our soil science f/as by considerable margins (69.2% men vs. 30.8% women for pooled data for all six countries in this study), and that the percentage of women in soil science f/as positions are similar to those for f/as women in many other scientific fields. There are differences in gender equity by soil science subdiscipline that vary by country. In countries where data are available to make comparisons, over the last 6–8 years, the gender gap has closed to some degree, both overall and for sub‐disciplines. Women also often hold leadership positions in numbers that are lower than their representation among the f/as and membership in professional societies. In addition, women are recognised with awards such as society fellowship in numbers lower than their overall representation would suggest. This study concludes that progress has been made on several fronts in the last 6–8 years, but there is still much work to be done to achieve gender equity in soil science academia and professional societies. It is recommended that soil science societies collect, analyse and compare data on gender in the discipline so that progress can be evidenced, tracked and encouraged.
Open Access
Unveiling the truth of interactions between microplastics and per- and polyfluoroalkyl substances (PFASs) in wastewater treatment plants: microplastics as a carrier of PFASs and beyond
(American Chemical Society, 2025) Ma, Min; Coulon, Frederic; Tang, Zhiwen; Hu, Zhiyuan; Bi, Ye; Huo, Mingxin; Song, Xin
Microplastics (MPs) and per- and polyfluoroalkyl substances (PFASs) are ubiquitous contaminants in environments, yet their co-occurrence and interactions remain insufficiently understood. In this study, we confirmed the concurrent presence of MPs and PFASs and their distinct distribution patterns in a wastewater treatment plant (WWTP) through a comprehensive sampling and analysis effort. Significant correlations (p < 0.05) were observed between specific types of MPs and PFASs, suggesting their shared sources. Moreover, MPs were identified as carriers of PFASs, with PFAS concentration ranging between 122 and 166 ng/g, predominantly consisting of perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA). The laboratory verification experiment revealed that PFASs could be leached from MPs in aqueous environments, in which commercial MPs exhibited higher leaching potential, with the highest combined concentration of perfluorooctanesulfonate (PFOS), PFOA, and PFBA reaching 10.4 ng/mL. PFOS demonstrated a desorption efficiency exceeding 120% in sorption/desorption experiments, confirming its release from the MPs themselves. These results highlighted the dual roles of MPs as both carriers and sources of PFASs. The identified contaminant profiles and correlations between MPs and PFASs across different matrices in WWTP provide valuable insights and form a basis for further research into proactive measures to effectively mitigate their environmental contamination.
Open Access
Nonlinear hydroelastic responses of a submerged horizontal plate under focused wave conditions: a cumulative fatigue perspective
(AIP Publishing, 2025-01-31) Ding, Haoyu; Huang, Luofeng; Zang, Jun
Most current analytical research on the hydroelastic interaction between water waves and submerged horizontal elastic plates remains within the scope of linear theory due to the underdevelopment of mathematical methods for solving nonlinear problems. To address this gap, this work employs an approach that combines computational fluid dynamics (CFD) with computational solid mechanics (CSM) to dynamically simulate the fully coupled nonlinear hydroelastic interactions between ocean waves and a submerged horizontal plate. This research highlights the significance of nonlinear point responses of a submerged horizontal plate under focused wave conditions. A phase-based harmonic separation method (i.e., phase-decomposition method) is used to isolate wave amplitude and force harmonic components in complex wave scenarios. This approach allows for the clean delineation of individual harmonics from the total wave force by controlling the phase of incident focused waves and is for the first time applied to the response analysis of elastic structures. This paper successfully used the phase-decomposition method to separate the individual harmonics of the point displacement of a horizontal elastic plate, directly demonstrating the significance of nonlinear responses. Additionally, the impact of plate rigidity, which relates to natural frequency, on nonlinear responses is investigated. The results indicate that plates with a certain dimensionless plate rigidity will exhibit more significant nonlinear responses. By cleanly separating each individual harmonic response, this study provides new insights into the nonlinear hydroelastic responses of a horizontal plate interacting with water waves and offers a new perspective on fatigue analysis, underscoring the importance of nonlinearity for future engineering designs.
Open Access
Enhanced data-driven economic assessment of fuel cell electric buses utilizing an improved Markov chain Monte Carlo approach
(Elsevier, 2025-02-10) Yuan, Xinjie; Xu, Miao; Hou, Zhongjun; Chen, Wenchuang; Huang, Yun; Lv, Jiaming; Xu, Xudong; Huang, Luofeng
Accurate economic assessment of proton exchange membrane fuel cell (PEMFC) vehicles is essential for optimizing control strategies in the PEMFC industry, which is largely driven by the need to reduce costs. Traditional data-driven approaches have focused on reconstructing typical driving cycles from real-world speed data, often overlooking the intensity and acceleration of these cycles. These factors are crucial for water and heat management in PEMFCs and can lead to inaccurate estimates of hydrogen consumption. This paper introduces a novel algorithm for typical driving cycles reconstruction based on real-world data, named the improved two-dimensional Markov Chain Monte Carlo (2D MCMC) approach using Metropolis-Hastings (M − H) sampling. The approach innovatively encodes the integration of real-time vehicle speed and acceleration sequences into a hierarchical 2D state transition probability matrix. To optimise both accuracy and computation time, the M − H based sampler is newly introduced to generate typical driving cycle without the computational burden of multiplying large matrices. Moreover, by integrating the agglomerative nesting (AGNES) alongside a comprehensive evaluation system that incorporates simulation and bench testing, the proposed approach effectively weights real-world route conditions in the economic assessment. Case studies involving 10 PEMFC hybrid buses in Shanghai, China, validate the effectiveness and robustness of the proposed method. Comparative analyses show that the relative errors in hydrogen consumption per 100 km between the reconstructed and real-world driving cycles are within 1.20–3.01% for all ten buses in Shanghai, with computation times reduced by up to 12.60% compared to the existing methods.
Open Access
On a journey to citywide inclusive sanitation (CWIS)? A political economy analysis of container-based sanitation (CBS) in the fragmented (in)formal city
(Taylor and Francis, 2025) Mdee, Anna; Ofori, Alesia Dedaa; Barrington, Dani; Anciano, Fiona; Dube, Mmeli; Hutchings, Paul; Kramer, Sasha; López-Valladares, Hellen; Parker, Alison; Riungu, Joy Nyawira; Ward, Christopher
Rapidly growing cities face the chronic challenge of access to safe, dignified and accessible sanitation, in contexts of inequality and informality. Technological and operational innovations, such as container-based sanitation (CBS), are promoted as relatively low-cost market-based circular economy off-grid solutions to deliver citywide inclusive sanitation (CWIS). However, in the absence of evidence that CBS is delivering on these promises, this paper asks: under what conditions can CBS services contribute to achieving CWIS goals? It applies a combined political economy and socio-technical regime analysis to examine multi-level governance in the sanitation sector and CBS service regimes in Cape Town, Lima, Nairobi and Cap-Haitien. Only Cape Town, a municipality-controlled system, demonstrates the necessary public authority that enables CBS to operate at scale. Yet, it is regarded by many residents in informal settlements as poor sanitation for poor people. This suggests that scaling CBS requires sustained public investment and strong coordinating authority.
Open Access
Membrane technology for water reuse in decentralised non-sewered sanitation systems: comparison of pressure driven (reverse osmosis) and thermally driven processes (membrane distillation and pervaporation)
(Royal Society of Chemistry (RSC), 2024-11-01) Mercer, Edwina V.; Davey, Christopher J.; Bajón Fernández, Yadira; Septien, Santiago; Tyrrel, Sean; Cartmell, Elise; Pidou, Marc; McAdam, Ewan J.
Membrane processes are an established barrier technology for water reclamation from wastewater. Applied at a household scale to improve sanitation practice, membrane technology can disrupt the source–receptor pathway, alleviate water scarcity through eliminating flush water and recover clean water for reuse. However, blackwater comprises a distinct composition compared to municipal wastewater, and there is only limited understanding on whether membrane selectivity is sufficient to produce water of sufficient quality for reuse. In this study, pressure driven and thermally driven membranes are evaluated for their potential to treat blackwater, by relating selectivity to relevant water quality standards (ISO 30500) and the transmission of volatile organic compounds (VOCs) that are primarily associated with faecal odour, and thus constitute a critical challenge to water reuse. Both pressure driven (reverse osmosis) and thermally driven (membrane distillation and pervaporation) membranes were able to produce water that conformed to category B of the ISO 30500 standard for the majority of determinants. A critical limiting factor was in the selectivity for ammonia and odorous VOCs which were generally poorly removed by reverse osmosis and membrane distillation. The high ammonia transmission was accounted for by the elevated pH of blackwater which shifted the ammonium equilibria toward volatile ammonia which is poorly separated by RO polymers, and is free to diffuse through the gas-filled micropores of the membrane distillation membrane. In contrast, greater ammonia and VOC separation was evidenced for the pervaporation membrane due to advanced polymer–solute interactions. In a preliminary assessment, the hydrophilicity exhibited by the membrane was also advantageous to withstanding fouling. If complemented with a polishing step to target the residual COD and VOCs (that may be of similar origin), pervaporation could deliver to category A standard for non-potable reuse. This is particularly advantageous for water scarce regions where solar or liquified fuels may be applied in favour of electricity for off-grid sanitation.