Search Results (932)

Background/Objectives: Severe arterial calcification remains a major challenge during femoropopliteal endovascular intervention, limiting luminal gain and increasing the risk of vessel-wall injury, restenosis, and bailout stenting. Pulsatile intravascular lithotripsy (PIVL) is a novel calcium-modification technology that converts pneumatic pulses into short-duration hydraulic pressure waves delivered through a non-compliant balloon. POWER PAD I evaluated the first-in-human feasibility, safety, and procedural performance of PIVL in calcified femoropopliteal arterial disease. Methods: POWER PAD I was a prospective, single-arm, two-center feasibility study. Adults with Rutherford category 2–4 symptomatic peripheral arterial disease and moderately or severely calcified superficial femoral or popliteal lesions were treated with PIVL, followed by adjunctive therapy when clinically indicated. Angiographic and duplex ultrasound outcomes were assessed by an independent core laboratory, and adverse events were adjudicated by an independent clinical events committee. Results: Nine patients underwent treatment of 20 lesions. Mean age was 76.2 ± 12.6 years, 19 lesions were severely calcified, and five lesions were chronic total occlusions. Patient-level device and procedural success were each achieved in 8 of 9 patients; technical success was achieved in all patients. Mean diameter stenosis decreased from 76.5 ± 18.0% before treatment to 28.1 ± 6.9% after PIVL-containing lesion preparation and before adjunctive drug-coated-balloon angioplasty, and to 20.6 ± 5.8% after adjunctive therapy. Mean minimal luminal diameter increased from 1.3 ± 1.0 mm to 3.8 ± 0.5 mm after PIVL-containing lesion preparation and to 4.3 ± 0.6 mm at final angiography. No perforation, distal embolization, thrombus, abrupt closure, no-reflow, bailout stenting, or grade D or higher dissection occurred. Freedom from clinically driven target-lesion revascularization was 100% at 30 days and 6 months. Conclusions: PIVL-containing lesion preparation was feasible in heavily calcified superficial femoral and popliteal lesions and was associated with substantial acute luminal gain before adjunctive DCB therapy and no severe angiographic complications. Favorable 6-month clinical and patency outcomes were observed after the combined treatment strategy of PIVL vessel preparation and adjunctive DCB therapy; therefore, longer-term outcomes cannot be attributed to PIVL alone. Larger controlled studies are warranted. Full article

Background: To present perioperative and follow-up outcomes of physician-modified endograft (PMEG) repair for juxtarenal and pararenal abdominal aortic aneurysms. Methods: This PRISMA 2020 systematic review and single-arm meta-analysis was registered with PROSPERO (CRD420261340339). PubMed, Embase, Web of Science, the Cochrane Library, and ClinicalTrials.gov were searched until December 2025. Eligible reports described full-text-confirmed cohorts of at least five patients treated with PMEG. The strict primary analysis required endpoint-separable juxtarenal or pararenal populations and used random-effects generalized linear mixed models for pooled proportions. Methodological quality and evidence certainty were assessed using the Joanna Briggs Institute checklist and GRADE framework. Results: Fifteen eligible reports described 981 patients before overlap adjudication; 10 reports originated from one institution and contained overlapping populations. After pathology and endpoint-level overlap adjudication, one to four independent populations informed each endpoint estimate, and single-source outcomes were not pooled. Technical success was 97.8% (95% CI, 94.8–99.1%; three populations, 228 patients), and 30-day mortality was 2.3% (95% CI, 1.1–4.8%; four populations, 299 patients). Acute kidney injury, stroke, and spinal cord ischemia occurred in 4.5%, 1.6%, and 1.7% of patients, respectively. During available follow-up, the single-source Type III endoleak estimate was 3.4% (7/203), any reintervention was 13.2% (95% CI, 2.9–43.7%; two populations, 217 patients; I² = 89.0%), and patient-level target-vessel occlusion was 2.4% (95% CI, 0.6–9.1%; 2 populations, 83 patients). Follow-up estimates were exploratory report-period proportions. GRADE certainty was very low for all key outcomes. Conclusions: PMEG repair demonstrated a high technical-feasibility signal and low observed early event rates in experienced centers, but clinical effectiveness and durability remain uncertain. The evidence base is dominated by overlapping expert-center reports and should not be interpreted as establishing equivalence or superiority to custom-manufactured FEVAR. Full article

This controlled proof-of-concept study evaluated whether interpretable RGB histogram descriptors extracted from smartphone images can be used to estimate nominal syrup addition within a single experimentally prepared honey-adulterant series. Eleven concentration-specific physical mixtures containing 0–50% syrup in 5% increments were prepared, and each mixture was represented by ten technical replicate images acquired under fixed white-light and camera settings while the sample vessel was rotated. Whole-image descriptors and a secondary patch-based representation were analyzed using partial least squares regression (PLSR), support vector regression (SVR), random forest (RF), gradient boosting (GB), and extreme gradient boosting (XGBoost). Nested leave-one-concentration-out validation kept all technical replicate images originating from each concentration-specific preparation within the same fold, thereby preventing replicate leakage between training and test data. Performance metrics were calculated from the eleven outer concentration-level predictions. The primary analysis allowed fold-specific selection from the complete pool of 102 RGB descriptors; PLSR performed best (R²_nested-LOCO= 0.980, RMSE_nested-LOCO = 2.22 percentage points, and MAE_nested-LOCO = 1.96 percentage points), followed by SVR (RMSE_nested-LOCO = 2.74 percentage points). Secondary restricted-feature analyses separately evaluated the G-channel descriptor family, the three mean RGB intensities, and G_mean alone. A performance-weighted cross-model SHAP analysis showed that location and percentile descriptors accounted for 67.7% of the total consensus importance score, with G_p95 ranked first. The G-channel descriptor family consistently outperformed the three RGB means, while G_mean provided a strong but less informative reference. Whole-image descriptors outperformed patch-based representation for four of five algorithms in the matched comparison. These results demonstrate the feasibility of quantitative syrup-addition estimation within the investigated controlled series rather than general honey-adulteration detection. Future studies should include independently prepared samples, broader honey–adulterant combinations, and evaluation of transferability across imaging devices and acquisition sessions. Full article

Maritime routes ensure connectivity between nations, carrying a vast flow of goods across borders, while ports serve as the critical junctions within this network, managing a wide spectrum of commodities from raw materials to finished goods. Ports also generate employment across numerous sectors and underpin a broad range of allied industries. A seaport is a maritime facility equipped with docks, cranes, and storage infrastructure for international trade, where ships load and unload cargo, containers, and passengers. Key functions of seaports include customs processing, warehousing, and vessel services, with major global hubs such as Shanghai, PSA Singapore, DP World, and Rotterdam handling immense volumes of cargo each year. In contrast, Bangladesh’s ports, Chittagong, Mongla, and Payra, play a vital role in sustaining regional commerce. Today, ports are widely recognized as essential capital infrastructure and prime movers of economic activity. Smart ports are automated facilities that leverage advanced digital technologies, including sensors, big data analytics, artificial intelligence (AI), machine learning (ML), deep learning (DL), augmented reality (AR), digital twins, the Internet of Things (IoT), and various automation systems, to optimize overall operational efficiency. These tools streamline cargo movement while embedding sustainable practices to protect the environment. Beyond operational gains, smart ports deliver faster, more advanced services to all stakeholders involved in port operations, including shipping companies, customs agencies, local communities, and other relevant parties. Renewable energy sources, electric vehicle charging stations, onshore power supply, and smart logistics infrastructure are among the defining sustainability features of smart ports in the present-day context. This study examines the current status and future development trajectory of Bangladesh’s sea ports in relation to the broader global imperative toward smart port transformation. Full article

This study developed a composite rejuvenator comprising recycled polyethylene wax (PREW), waste cooking oil (WCO), and epoxidized soybean oil (ESO) activated by the tertiary amine catalyst BDMA to improve the intermediate-temperature rejuvenation of aged SBS-modified asphalt binder. The binder was subjected to combined rolling thin-film oven and pressure aging vessel aging. Conventional tests, rotational viscosity, bending beam rheometer, multiple stress creep recovery, fluorescence microscopy, and Fourier transform infrared spectroscopy were used to evaluate macroscopic, rheological, and microstructural properties. Aging hardened and embrittled the binder, increased softening point and viscosity, reduced penetration and ductility, and disrupted the polymer-rich phase. PREW reduced flow resistance and retained relatively high-temperature structural stability, whereas WCO improved flexibility and flowability, although excessive softening impaired high-temperature stability. ESO/BDMA treatment was accompanied by changes in oxygen-containing functional group-related absorption regions and improved apparent connectivity of the SBS-rich phase. Among the tested temperatures, 120 °C provided the best overall balance among the evaluated properties, satisfying low-temperature stress-relaxation requirements while limiting high-temperature creep deformation. These results identify 120 °C as the preferred treatment temperature for the PREW/WCO/ESO-BDMA rejuvenation system. Full article

The propulsion performance and propeller design of ships have traditionally been evaluated mainly under calm-water conditions. However, under actual sea conditions, waves can increase added resistance, change the stern wake distribution, reduce propulsive efficiency, and affect cavitation behavior. This study evaluates the propulsion performance and designs a propeller for an 1800 TEU container ship under regular wave conditions using computational fluid dynamics. Resistance and self-propulsion simulations are conducted for eleven wavelength ratios in the range of $0.5\le \lambda /L_{PP}\le 2.0$, with a fixed wave steepness of $H/\lambda =0.01$. The results show that the required power increases significantly in the resonance wavelength range because of the combined effects of added resistance, wake variation, and reduced propulsive efficiency. The Brake Horsepower (BHP) transfer function obtained from the regular wave simulations is combined with representative sea-state spectra using the spectral method to estimate the Daily Fuel Oil Consumption (DFOC) under actual operating sea states. The total long term DFOC is estimated as 37.084 t/day. For the propeller design, the wake distribution at the propeller plane is analyzed at $\lambda /L_{PP}=1.1$, as a representative wave condition where the ship motion and propulsion performance variation become significant. The wake analysis shows that the instantaneous inflow changes considerably according to the wave phase, which can affect blade loading and cavitation. Based on this analysis, a new propeller geometry is designed with the cavitation performance as the primary consideration while also improving the propulsion performance. The designed propeller reduces the cavity volume over the selected wave phases and decreases the delivered power by approximately 2.1% in calm water and 3.4% in wave conditions. These results demonstrate the importance of considering wake variation and cavitation characteristics in practical propeller design under actual operating conditions. Full article

Given that large-scale storage and transportation of liquid hydrogen are key to realizing the hydrogen economy, tank containers have attracted much attention for their flexibility. To minimize evaporation losses, efficient support structures are essential for these liquid hydrogen tank containers. Herein, a carbon fiber-reinforced polymer (CFRP) suspension ring is developed to support the inner vessel of liquid hydrogen tank containers. By using a special resin matrix and optimizing its curing process, the suspension ring capitalizes on a small cross-sectional area and low thermal conductivity, thereby significantly mitigating the cold-bridge heat transferred from the outer vessel to the inner vessel. Experimental results demonstrate that the tensile strength, outgassing rate, and fatigue performance of the suspension ring at both 77 K (liquid nitrogen temperature) and 4 K (liquid helium temperature) can meet the design targets. Notably, its equivalent thermal conductivity was approximately 88% lower than that of a stainless steel structure of the same size. With the integration of this suspension ring into a 40 ft liquid hydrogen tank container, the daily liquid nitrogen evaporation rate was recorded below 0.082%/d. Furthermore, the holding time before the pressure reached 0.14 MPa exceeded 192 h with a 90% liquid hydrogen filling ratio. This work provides key technical support for high thermal insulation, long-endurance liquid hydrogen storage and transportation equipment. Full article

As the global energy sector and maritime industry transition toward carbon neutrality, Carnot batteries have emerged as a critical technology for flexible, long-duration energy management. Carnot batteries, which operate on a Power-to-Heat-to-Power principle, present a highly promising alternative to conventional electrochemical batteries. The present study provides a review of Carnot battery architectures, systematically evaluating their thermodynamic cycles, working fluids, Thermal Energy Storage media and key turbomachinery components. A comparative assessment of the current literature illustrates that system selection requires balancing round-trip efficiency, Energy Storage Density and Technology Readiness Level. According to the findings of the present study, high-temperature Brayton cycles offer robust baseline efficiencies of 60–80% whereas subcritical Rankine cycles benefit from commercial maturity and can achieve efficiencies exceeding 200% when integrated with cryogenic heat sinks like LNG. It should be clarified that efficiency values exceeding 100% represent “Apparent Round-Trip-Efficiencies (RTE)” resulting from the thermodynamic contribution of external exergy streams, such as LNG cryogenic cold, rather than standalone cycle efficiencies, which are strictly below 100%. In addition, volumetric energy density varies drastically based on the physical phase of the storage medium, scaling from under 1 kWh/m³ for unpressurized water to over 385 kWh/m³ for advanced thermochemical systems. Although most configurations currently remain in the prototyping phase, the technology holds transformative potential for the maritime sector. Carnot batteries can deliver a self-contained, zero-emission electrical power supply to cover the vessel’s electrical load requirements during harbor stays and transit within Emission Control Areas (ECAs) by dynamically capturing and storing shipboard waste heat during open sea transit. Full article

Maritime navigation efficiency is commonly assessed using isolated route, speed, energy, or traffic indicators that do not fully represent voyage context. This study proposes a context-aware framework based on GPS–AIS data fusion, planned-route geofencing, metocean information, and encounter-based validation. The Navigation Efficiency Resilience Index (NERI) combines target achievement, trajectory-derived response activity, and disturbance intensity into a bounded, time-resolved diagnostic index. The framework was evaluated using a Singapore–Montevideo container-ship voyage with 30 s position data, surrounding-vessel AIS, corridor-specific cross-track limits, and collocated metocean variables. The voyage-level mean NERI was 0.679, and its 10th percentile was 0.519. Lower values occurred mainly in constrained waters, approach areas, and the metocean-intensive Cape transition, whereas the Indian Ocean and South Atlantic legs achieved higher mean values of 0.704 and 0.736, respectively. For the analysed datasets, the regular own-ship position record produced more stable trajectory-derived indicators than the less regularly sampled own-ship AIS series, without implying an inherent accuracy advantage. The full NERI formulation achieved an AUROC of 0.83 and an AUPRC of 0.41 for CPA/TCPA conflict-window classification. NERI therefore provides a decomposable, plan-relative analytical layer for retrospective voyage monitoring and diagnostics, but it is not a direct safety or collision-risk measure. Full article

Background: ExPEC9V was a 9-valent vaccine candidate intended for the prevention of invasive extraintestinal pathogenic Escherichia coli (ExPEC) disease (IED). Here, we describe more than a decade-long formulation development trajectory of this vaccine candidate aimed at establishing a stable, robust and scalable drug product that maintains long-term stability while addressing potential manufacturing challenges and increasing the probability of successful global deployment. Methods: Selected formulation development studies of the ExPEC multivalent vaccine candidate are summarized, spanning formulation screening, confirmation, and design of experiments (DoE)-based robustness, stability and compatibility studies. A formulation initially developed for an early low-valency vaccine candidate was subsequently tested and confirmed for candidates with additional serotypes incorporated based on antigen heterogeneity evidence. Contact materials employed included primary packaging—polycarbonate (PC) and polyethylene terephthalate glycol (PETG) bottles, borosilicate glass vials, stoppers, and prefilled syringes; vessel types—bags and stainless steel vessels used in drug substance (DS) and drug product (DP) manufacturing; and varying concentrations of tungsten and hydrogen peroxide. An evolving analytical panel was applied to assess attributes such as purity, protein concentration and degree of O-acetylation. Results: A phosphate-based formulation containing sorbitol, methionine, and polysorbate 80 showed superior stability in screening and was confirmed as fit for purpose across increasing vaccine valency. The ExPEC 9V drug product displayed remarkable thermal and formulation robustness, long-term (3 years) stability at 2–8 °C in glass vials and prefilled syringes, and compatibility with assessed primary containers and manufacturing materials. DoE-based robustness studies defined acceptable excipient and pH ranges, supporting a wide formulation design space. Conclusions: The development trajectory of the ExPEC9V vaccine candidate demonstrates that early prioritization of a robust, scalable formulation that remains fit for purpose across valency evolution supports a stable late-stage manufacturable drug product. Full article

Port-related maritime emissions constitute a significant source of urban air pollution and greenhouse gas emissions, particularly in rapidly developing coastal cities. Within this context, the present study quantifies ship-related emissions at the Port of Casablanca, Morocco’s largest and most strategically important port, and evaluates their associated environmental and socio-economic impacts. A bottom-up methodology was applied to estimate emissions from vessel operations between 2017 and 2021. The inventory integrates vessel characteristics, engine specifications, operational load factors, emission factors, and the duration of maneuvering and hotelling phases to estimate emissions of CO₂, SO₂, NO_x, CO, NMVOCs, PM, PM₁₀, and PM_2.5. The emission inventory was subsequently coupled with damage cost factors to assess the external costs associated with shipping emissions. The obtained results demonstrate that CO₂ was the dominant emitted pollutant, representing approximately 97% of total emissions, whereas NO_x and SO₂ accounted for 2% and 1%, respectively. Bulk carriers emerged as the principal emission source (44%), followed by container vessels (36%), with the highest emission levels observed during 2018–2019, coinciding with increased port operations. Furthermore, the integration of emission inventories with damage cost factors demonstrated that NO_x, although emitted in much smaller quantities than CO₂, exerts a disproportionately higher environmental and societal burden due to its impacts on public health and ecosystem quality. This study provides one of the first integrated bottom-up emission inventories and external cost assessments for a Moroccan port. The proposed framework supports evidence-based decision-making for sustainable port management and demonstrates the need for emission reduction strategies that simultaneously address climate change and air quality objectives. Full article

The preservation of submerged cultural heritage depends on the ability to locate, document, and monitor sites before they are degraded or lost. Although the North American Great Lakes contain thousands of exceptionally well-preserved shipwrecks, their large geographic extent and diverse operating environments present significant challenges for efficient archeological survey. This study presents a multi-platform autonomous survey framework developed and implemented during 2021–2022 field campaigns in Lake Michigan and Lake Ontario. The framework integrates autonomous underwater vehicles (AUVs), autonomous surface vehicles (ASVs), crewed vessels, side-scan sonar, multibeam bathymetry, magnetometry, optical imaging, and field-based data review within a hierarchical workflow comprising wide-area assessment (WAA) reconnaissance, high-resolution geophysical (HRG) mapping, adaptive mission refinement, and visual confirmation. The surveys produced 19.72 km² of geophysical coverage, including side-scan sonar mosaics, bathymetric surfaces, magnetic anomaly maps, and optical imagery that supported archeological interpretation. A case study from Lake Ontario demonstrates the framework’s effectiveness through the confirmation of a previously undocumented wooden shipwreck using complementary acoustic, magnetic, and visual datasets. Beyond the individual discoveries, the results demonstrate how integrated autonomous systems improve survey efficiency, support adaptive decision-making, and provide scalable methods for digital documentation, baseline site characterization, long-term monitoring, and preservation of submerged cultural heritage in freshwater and marine environments. Full article

Background: Advancing age is incorporated as a strong risk variable in EuroSCORE II and is consistently associated with adverse outcomes after conventional coronary artery bypass grafting (CABG). Whether minimally invasive direct coronary artery bypass (MIDCAB)—which avoids both sternotomy and cardiopulmonary bypass—modifies this age-related risk in patients with single-vessel or LAD-predominant coronary artery disease remains insufficiently characterised. Methods: We retrospectively analysed 350 consecutive patients who underwent MIDCAB at Hannover Medical School between July 1999 and April 2025 (follow-up to April 2025). Elderly patients (age ≥70 years; n = 117) were compared with younger patients (age <70 years; n = 233) before and after 1:1 propensity score matching using greedy nearest-neighbour matching with a caliper of 0.2 × SD of the logit propensity score; age was excluded from the propensity model as it represented the exposure variable. A pre-specified sensitivity propensity model that additionally excluded EuroSCORE II (because EuroSCORE II contains an age component) was also evaluated. The primary endpoint was all-cause long-term mortality; secondary endpoints included perioperative complications and in-hospital outcomes. Long-term survival was assessed by Kaplan–Meier analysis and multivariable Cox proportional hazards regression, with a pre-specified parsimonious Cox model (age, LVEF, renal impairment) and cluster-robust standard errors on matched-pair identifiers. Results: Matching produced 109 pairs with excellent covariate balance (all standardized mean differences < 0.20). MIDCAB was completed without intraoperative conversion in all patients. No 30-day mortality, perioperative stroke, or new postoperative dialysis was observed in either age stratum (Clopper–Pearson 95% CI 0.00–3.33% for each zero-event outcome). Perioperative complications—including new-onset atrial fibrillation, re-exploration for bleeding, and intensive care unit and hospital length of stay—did not differ significantly between elderly and younger patients in the matched cohort (Newcombe 95% CI for risk differences all crossing zero; McNemar’s exact tests non-significant for all matched-pair binary endpoints; Hodges–Lehmann median difference for hospital length of stay +1.0 day, bootstrap 95% CI 0.0–1.0 days). At a median follow-up of 19.0 years (IQR 11.5–24.3; reverse Kaplan–Meier potential median 19.7 years), all-cause mortality was higher in the elderly (20.2% vs. 5.5%, p = 0.002; log-rank p = 0.001; exact McNemar’s p = 0.0025 for the matched-pair mortality endpoint). After multivariable adjustment, elderly age (≥70 years) was independently associated with long-term mortality (adjusted hazard ratio 4.48, 95% CI 1.79–11.20, p = 0.001), as was EuroSCORE II (HR 2.40 per unit, p = 0.034); a pre-specified parsimonious model (age, LVEF, renal impairment) with pair-cluster robust standard errors yielded an essentially identical adjusted HR for elderly age of 4.08 (95% CI 1.65–10.04, p = 0.002), and a sensitivity propensity model without EuroSCORE II yielded HR 3.95 (95% CI 1.68–9.29, p = 0.002). Conclusions: In this propensity-matched analysis with a median follow-up of ~19 years, MIDCAB was associated with excellent observed perioperative outcomes in appropriately selected elderly patients (no 30-day mortality, stroke, or new dialysis observed; upper 95% CI 3.3%) and no evidence of an excess of major in-hospital complications compared with younger patients within the statistical resolution of the cohort. The long-term mortality excess in the elderly is consistent with age-related life-expectancy curves in the source population; cause-specific mortality was not available in this cohort. External benchmarks from large MIDCAB cohorts in which long-term survival approximates that of the age-matched general population support this interpretation indirectly. These findings support MIDCAB as a feasible revascularization strategy associated with favourable observed early outcomes and long-term survival consistent with published MIDCAB literature, in appropriately selected elderly patients with single-vessel or LAD-predominant coronary artery disease treated at experienced centres. Full article

Accurate traffic state estimation (TSE) for port motorway networks is critical for mitigating congestion and improving operational efficiency in port cities. Port motorways have their specific traffic patterns, such as surges in container truck demand triggered by vessel arrival events. Considering this characteristic, we propose a novel TSE method named HGCN-VA, enabling a real-time inductive inference based on a graph neural network (GNN). The framework constructs a heterogenous graph comprising both road sensors and ports, while introducing an influence weight learning module based on attention mechanisms to adaptively align vessel events with their traffic consequences. A hierarchical spatial module is further designed, where initial heterogeneous diffuse graph convolution layers explicitly model cross-domain interactions between port and sensor nodes, followed by standard diffusion graph convolution layers to capture traffic propagation patterns. Extensive experiments on a simulation port dataset demonstrate that HGCN-VA outperforms baselines in TSE accuracy. Ablation studies further validate the effectiveness of incorporating vessel information and the proposed heterogeneous spatial modeling strategy. Full article

This paper evaluates whether hydrogen-based marine fuels were financially feasible in the European maritime sector in mid-2026 without subsidies, grants, contracts for difference, preferential carbon-price treatment, or other public subventions. A techno-economic model compares pure hydrogen fuel cells, hydrogen internal combustion, ammonia combustion and fossil marine fuels for general cargo ships, container ships and passenger liners. The model combines 2026 bunker quotations, fuel-energy properties, EU ETS exposure, FuelEU Maritime requirements, ammonia cost evidence and scenario assumptions for delivered renewable hydrogen. Results show that fossil-fuel-equivalent useful propulsion costs remain substantially lower than hydrogen and ammonia alternatives under a no-support baseline. Current EU policy narrows the gap but does not close it. The hypothesis is confirmed: in mid-2026, hydrogen-based propulsion is not commercially feasible without public support, except for exceptional pilots and premium fixed-route niches. Under the paper’s central scenarios, unsubsidised parity is unlikely before 2032–2035 for short routes and 2035–2040 for larger vessels. Green methanol is treated as a complementary hydrogen-derived pathway whose easier storage and handling may favour selected services, although its lifecycle benefit depends on renewable hydrogen and a sustainable carbon source. Full article