Search Results (222)

Hydrogen combustion is known to be fast compared to traditional hydrocarbon fuels. The fast combustion leads to a higher thermal efficiency. In this research a 600 cc single cylinder hydrogen engine was tested at 1250 rpm, lambda = 2 and 3, and three load levels (load was represented by Manifold Absolute Pressure (MAP); MAPs tested were 75, 95 and 120 kPa) and compared to operation with gasoline and propane. The fast burn duration (Mass Fraction Burnt MFB10% to MFB90%) and the MFB 50% were determined and analyzed. The hydrogen MFB50% location for Minimum Timing for Best Torque (MBT) was found to occur at around the typical 8 Crank Angle Degrees (CADs) After Top Dead Center (ATDC). Measurements of ignition delay based on the fast data direct measurement of spark ignition coil current drop to the change in polarity of net heat release are presented. With shifts towards direct injection and higher injection pressures, consideration was given to the hydrogen pressurization penalty, where it was calculated that pressurizing hydrogen to 100 bar at the flow required for lambda = 2 operation is 2.3 bar, i.e., higher than the Friction Mean Effective Pressure (FMEP)! Furthermore, hydrogen is widely cited to have a higher heat loss than typical hydrocarbon fuels. In this paper, detailed analyses at lambda 2 and lambda 3 showed that hydrogen in fact has lower heat losses. Full article

Minibus taxis are Cape Town’s ubiquitous public transport mode, carrying about 69% of public transport users. As electric mobility accelerates, the implications of electrifying this paratransit fleet must be quantified. We present a multi-perspective assessment of energy, environmental and operator impacts of electric minibus taxis (eMBTs). Using a high-resolution tracking dataset representative of MBT operations in Cape Town, South Africa, we estimate daily charging energy demand, compare greenhouse gas and particulate matter emissions for electric and internal combustion operation under South Africa’s coal-dominated grid, and evaluate the operator’s total cost of ownership. Key results show that eMBTs require approximately 50.8 kWh of energy per day, based on the fleet’s median daily distance. Under current grid conditions, diesel minibus taxis emit 14.37% less CO₂e than eMBTs, but eMBTs drastically reduce noise pollution and particulate matter emissions when compared to diesel vehicles. Despite higher purchase prices, eMBTs can reduce operating costs and become financially attractive under favourable electricity prices and financing conditions. The study provides evidence to guide charging infrastructure planning, grid policy and incentive design for paratransit electrification in developing regions. Full article

This study assesses the distribution of nutrients, trace elements, and heavy metals across different granulometric fractions of municipal solid waste (MSW) compost from three regions: Kaunas and Alytus (Lithuania) and Daugavpils (Latvia). Samples were collected from mechanical biological treatment plants (MBTPs) and fractionated into six different granulometric fractions (>5 mm, 5–2.5 mm, 2.5–1 mm, 1–0.5 mm, 0.5–0.2 mm, and <0.2 mm). Each fraction was subjected to physicochemical characterization. Macronutrients (Ca, K, Mg, P), trace elements (Al, As, Co, Fe, Mn, Mo), and heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were analyzed using ICP-OES in triplicate. Results showed that essential nutrients and toxic metals were retained more in the finer fractions (<1 mm). In contrast, undesirable impurities, mainly glass, were retained in the coarse fractions across all the studied areas. All fractions in the compost samples of Kaunas, and coarse fractions (>5 mm, and 5–2.5 mm) of Alytus and Daugavpils are suitable to use as a soil amendment only if the undesirable impurities are removed to the acceptable limits in the coarse fractions. The fine fractions of Alytus have higher levels of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn), while Daugavpils showed higher levels of Cd, Cu, Ni, and Zn, exceeding the EU limits. Regarding physical fractionation, results showed that nutrients and heavy metals increased in the compost as particle size decreased. Our findings suggest that removing particle sizes < 1 mm and large impurities from the coarse fractions can enhance compost quality. Overall, particle-size fractionation can improve the consistency and safety of MBT-derived MSW compost for reuse in circular waste management systems. Full article

Egypt’s municipal solid waste (MSW) sector faces persistent challenges due to increasing generation rates, limited recovery, and a high organic fraction, motivating the selection of appropriate biological treatment options within Mechanical–Biological Treatment (MBT) systems. This study compares composting-based MBT and biodrying-based MBT for a case application in Alexandria, Egypt, using an integrated techno-economic and greenhouse gas (GHG) assessment. Discounted cash-flow modelling was applied using defined CAPEX and OPEX, along with revenue from recovered products. GHG accounting used documented emission factors and activity data against an unmanaged landfill baseline representative of current disposal practices. The system boundary covers waste reception and mechanical processing, biological treatment, process energy use, and residual disposal. Results show that composting achieves higher financial performance (NPV USD 2.55 million) than biodrying (NPV USD 0.99 million), while delivering a 48.5% reduction in net system GHG emissions relative to the baseline. Sensitivity analysis indicates that the comparative ranking is primarily driven by electricity prices, revenue assumptions, CAPEX, and baseline-related emissions parameters. Under the defined assumptions, composting is the preferred MBT biological pathway for the analyzed case, and interpretations are limited to the evaluated boundaries. Full article

The MALDI-TOF MS Bruker Biotyper MBT subtyping IVD module enables the early detection of cfiA-positive Bacteroides fragilis (cfiA+ BF) during bacterial identification. However, the relationship between genetic positivity, phenotypic resistance, and clinical outcomes has not been fully elucidated. This retrospective study analyzed B. fragilis isolates from three Hong Kong hospitals between 2021 and 2025 to examine their prevalence and the clinical utility of MALDI-TOF MS in rapid cfiA detection. Antibiotic susceptibility testing, cfiA gene detection using MALDI-TOF MS, and Oxford Nanopore sequencing were performed. Medical records were reviewed, and univariate analyses and multivariate logistic regression were used to identify factors associated with cfiA positivity and 30-day all-cause mortality. Overall, B. fragilis exhibited a high rate of antibiotic resistance. Concomitant resistance to carbapenems and metronidazole was identified in three isolates. Among the 166 isolates, 40 (24.1%) were cfiA-positive. cfiA detection by MALDI-TOF MS showed 100% concordance with the gene sequencing results and correlated strongly with phenotypic carbapenem resistance (Φ = 0.82, p < 0.001 for meropenem; Φ = 0.70, p < 0.001 for ertapenem; Φ = 0.63, p < 0.001 for imipenem). Phylogenetic analysis revealed two distinct clusters corresponding to cfiA status, each exhibiting genetic diversity based on multi-locus sequence typing (MLST). The cfiA+ BF isolates demonstrated high-level phenotypic carbapenem resistance in the presence of upstream insertion sequences. The predominant sequence type (ST) among cfiA+ BF isolates was ST157, and 70% of ST157 isolates harbored IS1187 in the upstream region of cfiA. Gene sequencing also identified other emerging beta-lactamase genes bla_OXA-347 and bla_MUN. The 30-day all-cause mortality following B. fragilis infection was 13.3%, with independent predictors including a high Charlson Comorbidity Index (OR = 1.30; p = 0.02) and the absence of early source control (OR = 4.84; p = 0.03). This study highlights the widespread occurrence of cfiA+ BF in Hong Kong and the clinical significance of rapid cfiA detection. Continuous surveillance is essential to monitor the ongoing threat of antibiotic resistance in B. fragilis. Full article

One of the main obstacles to producing natural rubber-modified asphalt is the difficulty of mixing Technical Specification Natural Rubber (TSNR) or its compounds with asphalt, leading to long mixing times and high costs. This study aims to evaluate the use of 60/70 penetration asphalt as a plasticizer to accelerate the mixing process and improve the rheological properties of modified asphalt using Technical Specification Natural Rubber (TSNR). The production process for technical specification natural rubber-modified asphalt involves two stages: the production of the technical specification natural rubber compound (CTSNR) and the production of CTSNR-based modified asphalt (CTSNRMA). The CTSNR production process begins with mastication of technical specification natural rubber (TSNR), followed by the addition of activators (zinc oxide, stearic acid), accelerators (Mercaptobenzothiazole sulfenamide (MBTS)), antioxidants (2,2,4-Trimethyl-1,2-dihydroquinoline (TMQ)), and 60/70 penetration asphalt as a plasticizer (at concentrations of 30%, 40%, and 50%). After homogeneous mixing for 30–60 min, the CTSNR is diluted 5–10 mm for the next mixing stage with hot asphalt at 160–170 °C. The best results of this study showed that CTSNR-modified asphalt with 4% rubber content and 50% plasticizer (CTSNRM-450) successfully reduced the mixing time to 16 min, making it more efficient than the traditional method, which takes up to 180 min. The addition of asphalt plasticizer decreased penetration to 35.6 dmm and increased the softening point to 55.4 °C. The CTSNRMA-440 formula, with 4% rubber content and 40% plasticizer, produced the best results in terms of storage stability, meeting the ASTM D5892 standard with a softening-point difference of 0.95 °C, which is well below the threshold of 2.2 °C. The CTSNRMA-440 sample achieved a Performance Grade (PG) of 76, suitable for hot-climate conditions, with a significant reduction in mixing time, greater stability, and increased resistance to high temperatures. Full article

A major factor in worldwide ecological harm is the large quantity of municipal solid waste generated because of rapid industrialization and population growth. Nowadays, there are numerous mechanical, biological, and thermal waste treatment processes that can reduce the amount of landfilled waste. A variety of analytical tests are conducted to evaluate the potential risks that landfills pose to human health and the environment. Among these, laboratory leaching tests are commonly employed to assess the release of specific waste constituents that may become hazardous to the environment. Municipal solid waste (MSW) management poses significant environmental risks due to leachate contamination in bioreactor landfills, where acidic conditions (pH ≈ 5) can mobilize heavy metals. This study evaluates the reliability of leaching tests for biodried reject MSW from CWMC Marišćina, Croatia, by comparing standard EN 12457-1 and EN 12457-2 methods (L/S = 2 and 10 L/kg) with simulations of aerobic degradation using acetic acid (10 g/L) to maintain pH = 5 over 9 days. Waste composition analysis revealed plastics (35%), paper/cardboard (25%), metals (15%), and glass (10%) as dominant fractions. Although the majority of parameters determined through standard leaching tests remain below the maximum permissible limits for non-hazardous waste, simulations under acidic conditions demonstrated substantial increases in eluate concentrations between days 6 and 9: Hg (+1500%), As (+1322%), Pb (+1330%), Ni (+786%), and Cd (+267%), with TDS rising 33%. These results highlight the underestimation of risks by conventional tests, emphasizing the need for pH-dependent methods to predict in situ leachate behavior in MBO-treated waste and support improved EU landfill regulations for enhanced environmental protection. Full article

Tuberculosis (TB) remains a major global health concern, underscoring the urgent need for innovative therapeutic approaches. In this study, we aimed to identify potential inhibitors of phenyloxazoline synthase MbtB, an essential enzyme involved in the iron acquisition pathway of Mycobacterium tuberculosis and a promising target for drug development. To this end, a curated library of FDA-approved drugs from the ZINC database was systematically screened to uncover compounds with potential inhibitory activity against MbtB.Multiple conformations of the substrate’s transition state structure were utilized as query models. Conformational ensembles for both the query molecules and compounds within the FDA-approved drug library were generated using Balloon (v1.8.2). Virtual screening was then conducted using ShaEP (v1.4.0), which evaluates shape and electrostatic potential similarity, resulting in the identification of several promising candidate inhibitors.Molecular dynamics simulation was performed to understand molecular-level interaction between the top 5 hits and the target protein. Top hits will be procured, testing their anti-TB activity in ion-rich and ion-deprived media, as reported in earlier publications. Full article

Background/Objectives: The ¹³C-Methacetin Breath Test (MBT) is a non-invasive tool to evaluate hepatic microsomal function via exhaled ¹³CO₂, reflecting cytochrome P450 1A2 (CYP1A2)-mediated metabolism. Despite decades of evidence demonstrating its utility in diagnosing cirrhosis, stratifying liver disease severity, and predicting outcomes, MBT adoption remains limited due to methodological inconsistencies and variable diagnostic thresholds. This review aimed to summarize MBT data in adults and assess its diagnostic and prognostic performance. Methods: A literature review was conducted using PubMed, Web of Science, and Scopus. Eligible studies included those applying oral or intravenous methacetin with defined reference values or diagnostic cutoffs. Outcomes of interest were percent dose recovery (PDR), cumulative PDR (cPDR), and LiMAx^® values. Due to heterogeneity in protocols, units, and endpoints, results were synthesized narratively. Results: Healthy individuals typically demonstrated rapid metabolism (e.g., cPDR30 10–15%), whereas cirrhotic patients showed significantly reduced values (e.g., cPDR30 ≈ 1%). Diagnostic cutoffs varied widely (<0.35% to <8%), reflecting methodological and population differences. MBT reliably identified advanced liver disease but showed inconsistent sensitivity for early-stage fibrosis and metabolic dysfunction-associated steatotic liver disease. Variability in dosing, timing, measurement duration, and analytic technique limited cross-study comparability. Conclusions: MBT is a validated, dynamic marker of liver function with both diagnostic and prognostic relevance. However, inconsistent protocols and thresholds hinder its clinical implementation. Standardization of MBT procedures, reference ranges, and reporting metrics is essential. A harmonized protocol (“MBT-60”), supported by multicenter validation, demographic stratification, and direct comparison with structural and serologic liver tests, is recommended to facilitate MBT integration into routine hepatology practice. Full article

Organophosphate pesticides are among the most persistent and toxic contaminants in aquatic environments, requiring effective strategies for detection and remediation. In this work, density functional theory (DFT) calculations were employed to investigate the adsorption of nine representative organophosphates (glyphosate, malathion, diazinon, azinphos-methyl, fenitrothion, parathion-methyl, disulfoton, tokuthion, and ethoprophos) on mercaptobenzothiazole disulfide (MBTS) and MBTS-functionalized graphene (G–MBTS). All simulations were performed in aqueous solution using the SMD solvation model with dispersion corrections and counterpoise correction for basis set superposition error. MBTS alone displayed a range of affinities, suggesting potential selectivity across the organophosphates, with adsorption energies ranging from 0.27 to 1.05 eV, malathion being the strongest binder and glyphosate the weakest. Anchoring of MBTS to graphene was found to be highly favorable (1.26 eV), but the key advantage is producing stable adsorption platforms that promote planar orientations and $\pi$–$\pi$/dispersive interactions. But the key advantage is not stronger binding but the tuning of interfacial electronic properties: all G–MBTS–OP complexes show uniform, narrow HOMO-LUMO gaps (∼0.79 eV) and systematically larger charge redistribution. These features are expected to enhance electrochemical readout even when adsorption strength was comparable or slightly lower (0.47–0.88 eV) relative to MBTS alone. A Quantum Theory of Atoms in Molecules (QTAIM) analysis of the G–MBTS–malathion complex revealed a dual stabilization mechanism: multiple weak C–H⋯$\pi$ interactions with graphene combined with stronger S⋯O and hydrogen-bonding interactions with MBTS. These results advance the molecular-level understanding of pesticide–surface interactions and highlight MBTS-functionalized graphene as a promising platform for the selective detection of organophosphates in water. Full article

Detailed paleomagnetic and rock magnetic investigations of the Paks loess (Hungary) were conducted to determine the stratigraphic position of the Matuyama–Brunhes Transition (MBT) and to attempt to reveal the sign of any possible influences of geomagnetic field change on the climate during the geomagnetic polarity reversal. Progressive thermal and alternating field demagnetizations of samples showed that the reverse polarity field begins to fluctuate in a stratigraphic position of the well-developed, so-called Paks Double 2 (PD2) paleosol (formed in Marine Isotope Stage 19, MIS19), and continues up to the middle-to-upper part of the overlying paleosol-to-loess transition layer (MIS19 to 18). Considering the relative paleointensity variation from Paks, this is consistent with various global records. Along with the weakening of the geomagnetic field, changes in environmental proxies were also recognized. Magnetic proxies indicate cooling during the MIS19 interglacial period. Theoretically, it may be connected to the weakening of the geomagnetic field. Still, there are alternatives to be considered, which may form the same features thought to be the result of the Umbrella effect. Full article

This study outlines a high-yield green method for synthesizing MBT using aniline, carbon disulfide and sulfur as raw materials via a one-step reaction combined with high–low-temperature extraction. The process is supported by experimental results and lab-scale tests, and the operating conditions of the amplification process are evaluated using Aspen Plus simulation software, supplemented with Gaussian09 calculations. The sensitivity analysis results indicate that the MBT yield reaches its maximum value when the feed mass ratio of S:CS₂:C₆H₇N:C₇H₈ is 6:17:20:90. Additionally, setting the reaction temperature to 240 °C and pressure to 10 MPa improves the MBT synthesis yield from 58% to 82.5%. Optimal condensation and extraction conditions are achieved at −30 °C and 1 atm, followed by a separation step at 40 °C. The simulation results provide valuable guidance for the industrial production of MBT. Full article

Glycerol Dialkyl Glycerol Tetraethers (GDGTs) are microbial membrane lipids that can provide crucial information for identifying organic carbon sources and understanding paleoenvironments. Despite numerous studies reporting the presence of GDGTs in various terrestrial and marine environments, there is a paucity of reports concerning GDGTs in mangrove wetlands that are characterized by unique hydrological conditions and disproportionately high accumulation rates of blue carbon (i.e., carbon sequestered in coastal ecosystems, where tidal flooding and anaerobic sediments facilitate exceptional long-term carbon storage). This study investigates GDGTs in 81 sediment samples from 5 sediment cores collected from three Asian mangrove wetlands in Bangladesh, Hong Kong, and Guangxi Province, China. The Hong Kong mangrove sediments had the highest GDGT concentration (370.18 ± 58.00 ng·g⁻¹ dws), followed by Bangladesh mangrove sediments (136.70 ± 41.70 ng·g⁻¹ dws), while Guangxi mangrove sediments had the lowest (100.80 ± 28.71 ng·g⁻¹ dws). All samples demonstrated high BIT index values (>0.8), low IIIa/IIa index values (0.09–0.19) and the predominance of tetramethylated brGDGTs (70.38 ± 2.21%), indicating that terrestrial inputs are the primary source of organic carbon. Despite overall low methylation index (MI) values (0.15–0.35) and GDGT-0/Cren ratios, deeper sediment samples in the lower part of HK exhibited GDGT-0/Cren > 2, likely reflecting enhanced contributions of methanogenic archaea under distinct redox conditions compared to upper sediments. This in situ production may complicate the application of GDGT-based paleo-proxies, as indicated by the substantial deviations between CBT’-pH (MBT’_5ME-temperature) and measured pH (instrumental temperature). The dominant bacterial phyla in the mangrove sediments of Guangxi and Bangladesh were Proteobacteria, Actinobacteriota, Chloroflexi, Acidobacteriota, and Firmicutes (>70% relative abundance). However, correlations between microbial community compositions and brGDGT isomers are different among sampling sites. Our study emphasizes that site- and depth-specific microbial activity may significantly contribute to organic matter cycling and the in situ production of GDGTs in mangrove sediments. These factors should be taken into account for organic carbon sequestration and the validity of GDGT-based paleo-proxies in mangrove wetlands. Full article

The increasing demand for on-orbit servicing (OOS), such as satellite life extension and space debris removal, has highlighted the need for research into precise relative navigation between space objects. Model-based tracking (MBT) was applied using the imaging data for relative navigation, incorporating SPNv2 (Spacecraft Pose Network v2) for an initial pose estimation. Furthermore, the performance of General Loss was evaluated by applying it during the model tracking processes and comparing it with seven other robust M-estimators, including Tukey, Welsch, and Huber. The simulations were conducted in a ROS–Gazebo environment that emulated a rendezvous with the International Space Station (ISS). Six approach profiles were generated by pairing three mutually different conic-section apertures with two attitude modes—boresight locked on the ISS versus boresight fixed on the inertial origin—producing six distinct spiral trajectories that bring the chaser from 500 m to 100 m along the depth axis of the camera. General Loss achieved superior estimation accuracy in most profiles. Thus, the proposed algorithm, which integrates General Loss into the MBT-based relative navigation framework, provides robust and stable performance in the presence of diverse residual distributions and outliers. In the few instances where it did not yield the very best results, the initial error arose from matching virtual edges—generated according to the sample weight distribution—to the actual edges in the image frame; notably, by the end of the simulation, when the camera reached a depth of approximately 100 m, these errors were substantially reduced. Thus, the proposed algorithm, which integrates General Loss into the MBT-based relative navigation framework, provides robust and stable performance in the presence of diverse residual distributions and outliers. Full article

Recent advancements in deep learning have significantly enhanced brain tumor segmentation from MRI data, providing valuable support for clinical diagnosis and treatment planning. However, challenges persist in effectively integrating prior medical knowledge, capturing global multimodal features, and accurately delineating tumor boundaries. To address these challenges, the Hybrid Network for Multimodal Brain Tumor Segmentation (HN-MBTS) is proposed, which incorporates prior medical knowledge to refine feature extraction and boundary precision. Key innovations include the Two-Branch, Two-Model Attention (TB-TMA) module for efficient multimodal feature fusion, the Linear Attention Mamba (LAM) module for robust multi-scale feature modeling, and the Residual Attention (RA) module for enhanced boundary refinement. Experimental results demonstrate that this method significantly outperforms existing approaches. On the BraT2020 and BraT2023 datasets, the method achieved average Dice scores of 87.66% and 88.07%, respectively. These results confirm the superior segmentation accuracy and efficiency of the approach, highlighting its potential to provide valuable assistance in clinical settings. Full article