Search Results (62,205)

We report the enhancement of organic photodetector (OPD) performance through the incorporation of CsPbBr₃ perovskite nanocrystals (PNCs) into P3HT:PCBM devices. The optimized device (HPD_01) exhibits a maximum responsivity of 0.083 A/W and a specific detectivity of ~4.7·10¹⁰ Jones, and a minimum NEP of 5.2·10⁻¹² W·Hz^−1/2 at the self-powered operating point (V ≈ 0 V), outperforming the nanoparticle-free reference. Frequency- and distance-dependent measurements under visible light communication conditions demonstrate that the optimized device maintains strong signal detection up to 1 MHz and at distances exceeding 15 cm. Notably, the external quantum efficiency spectra reveal an additional contribution in the 450–575 nm range, which is absent in the reference device. This enhancement is consistent with a radiative absorption–reemission energy-transfer mechanism, supported by quantitative spectral overlap analysis showing that 99.5% of the PNC photoluminescence falls within the 450–575 nm EQE enhancement window and that the maximum differential EQE gain occurs at 519 nm—only 2 nm from the PNC emission peak. Our results suggest that controlled PNC incorporation enables efficient optical energy coupling, leading to high-sensitivity, fast-response OPDs suitable for optical communication applications. Full article

Background: Successful healing of chronic apical periodontitis after endodontic treatment requires a reduction in the size of the radiolucent area and the healing of the bone. This study aimed to compare the effects of different irrigation activation techniques on healing in single-rooted mandibular premolar teeth with periapical lesions of endodontic origin. Methods: A total of 132 systemically healthy patients with mandibular single-rooted premolar teeth and a periapical index (PAI) score ≥ 3 were assigned to five experimental groups (Sonic activation, Passive ultrasonic irrigation, Photon-Induced Photoacoustic Streaming, Shock Wave Enhanced Emission Photoacoustic Streaming and Manual dynamic activation) and a control group (Conventional Syringe Irrigation). After access cavity preparation, the canals were prepared up to three sizes larger than the initial apical diameter with 5 mL of 2.5% NaOCl used between each file. Final irrigation was performed via the assigned activation system. The root canals were obturated with gutta-percha in a single visit. The effects of the activation systems on healing were compared at 1-year follow-up. The primary outcome measure was the change in lesion diameter. PAI score and fractal dimension (FD) were evaluated as secondary outcomes. Results: At the 1-year follow-up, FD values significantly increased, PAI scores and lesion size decreased in all groups compared with baseline (p < 0.001). However, the increase in FD was comparable among the irrigation groups (p > 0.05). In contrast, lesion size reduction and PAI-based healing rates favored the laser-activated groups. The PAI scores and lesion size in the control group were significantly greater than that in the laser groups (p < 0.05). Conclusions: At the 1-year follow-up, all the groups presented similar FD increases, while the laser irrigation groups presented significantly greater reductions in lesion size than did the control group. Full article

Porous medium combustion technology, renowned for high efficiency and low emissions, is widely applied in industrial and heating fields. This study numerically investigates pore-scale heat transfer, flame morphology, reaction rate distribution during standing combustion in a one-layer randomly packed bed, and flow parameter effects on flame behavior. A 3D randomly packed model (tube-to-particle diameter ratio D/d = 10) is developed using the discrete element method (DEM) and coupled with computational fluid dynamics (CFD) to resolve pore-scale transport processes. Results show that exothermic combustion converts internal energy to kinetic energy, significantly accelerating pore-scale flow velocity in the combustion zone. Increasing the equivalence ratio enhances flame stability, elevating solid–fluid temperatures by 200 K and expanding the combustion zone volume by 20%. The pore Reynolds number promotes inertial mixing and heat redistribution, limiting the solid–fluid temperature difference to 10 K. Local flames evolve from dispersed to wrinkled and undulating. These findings elucidate pore-scale combustion dynamics and guide packed-bed reactor design and optimization. Full article

In livestock-grazed pastures, urine patches are a major contributor of nitrous oxide (N₂O) emissions, and the use of nitrification inhibitors (NIs) has the potential to reduce N losses from urine patches using New Zealand (NZ)-devised Spikey^®—a ground-based machine that measures the change in soil conductivity from the deposited urine patches. Our ongoing research suggests that the efficacy of on-farm targeted NIs treatment requires suitable inhibitor concentrations within urine patches to be achieved to reduce N₂O emissions. This study evaluates the effect of varying NI rates and volumes on reducing N₂O emissions. The application rates for NIs were 1.6 g and 3.2 g dicyanamide (DCD) patch-1 and 0.96 g and 1.92 g of 3, 4-dimethylpyrazole phosphate (DMPP) patch⁻¹, using 100, 150, and 200 mL inhibitor solutions. These rates were higher than those used in previous studies to ensure an adequate supply of inhibitors above the threshold concentration within the urine patch and to enhance the inhibitor efficacy in reducing N₂O emissions. This study points to two important aspects: Determine the optimum inhibitor concentration required to eliminate, minimise/reduce N₂O emissions and ensure that at the optimised amounts of inhibitor application rates, inhibitor residues are below their maximum residue level (MRL) in the food chain and environment, and eliminate their potential harm to human health. Full article

Halide double perovskites with near-infrared (NIR) emission are promising for optoelectronic applications. NIR-II (1000–1700 nm) emission, in particular, is attractive due to its strong tissue penetration, high spatial resolution, and low biological light damage risk. However, materials capable of NIR-II emission often require additional sensitizers and suffer from issues such as narrow emission bandwidth and low photoluminescence efficiency. In this work, we report a Re⁴⁺ doping strategy using Cs₂WCl₆, a vacancy–ordered double perovskite, to achieve efficient NIR-II emission. Spectroscopic and dynamic measurements reveal energy transfer between the Cs₂WCl₆ matrix and the Re⁴⁺ centers, resulting in efficient broadband NIR-II emission centered at 1345 nm (FWHM ≈ 87 nm), along with broad excitation ranging from 250 to 850 nm. The optimal NIR-II emission occurs at 1345 nm with a photoluminescence quantum yield (PLQY) of 29.83% when the Re⁴⁺ doping concentration is 1%. This work demonstrates an efficient, sensitizer-free method for achieving broadband NIR-II emission and provides a new material strategy for high–performance double perovskites NIR light sources. Full article

The liner shipping industry is thriving in the low-carbon transition, and optimizing operational strategies for liquefied natural gas (LNG) dual-fuel ships has become a research hotspot. This research examines the impacts of the carbon tax, emission control area (ECA) policies, fuel price discounts and methane slip rate on fuel management strategies. Firstly, to reduce liner operating costs and adhere to ECA policies, this study develops a basic optimization model. Further, the model is extended to take into account the impact of fuel price discounts. Secondly, by linearizing multiple nonlinear terms, the operational strategies are obtained. Thirdly, taking a real vessel sailing between the Far East and Northwest Europe as a case study, this study identifies the ports for LNG and very low sulfur fuel oil (VLSFO) bunkering, determines the bunkering amounts and calculates the planned speeds. Furthermore, sensitivity analyses are conducted on fuel price difference, carbon tax rate and methane slip rate. Results show that fuel price difference, carbon tax rate, methane slip rate and fuel price discount exert a significant impact on ship operational decisions. To ensure the effectiveness of maritime decarbonization regulations, authorities should monitor ship engines with high methane slip rates. This study offers important references for shipping enterprises to meet ship emission policies and simultaneously cut operational costs. Full article

With rising global energy demand and the gradual depletion of petroleum-based resources, interest in alternative fuels for internal combustion diesel engines (ICDEs) has increased. In ICDEs, firing-related and mechanical excitations may result in adverse vibration and noise responses. This study examines whether incorporating sour cherry pit pyrolysis oil (SCPO) with n-butanol and 2-ethylhexyl nitrate (2-EHN) may reduce vibration and noise under constant-load, steady-state operating conditions compared with neat diesel (D100). For the experimental tests, five fuel types were prepared: one neat diesel fuel and four blended fuels with a constant diesel fraction of 40% and a fixed 2-ethylhexyl nitrate (2-EHN) content of 5%, while the SCPO and n-butanol fractions were varied (D40/SCPO0/B55/2-EHN5, D40/SCPO5/B50/2-EHN5, D40/SCPO10/B45/2-EHN5, and D40/SCPO15/B40/2-EHN5). Experiments were performed using a single-cylinder ICDE at a fixed load of 10 Nm under steady-state conditions at engine speeds of 1500, 1800, 2400, 3000, and 3600 rpm. For each operating condition, vibration and noise data were recorded over a 10.4 s window. Experimental findings indicate that D40/SCPO10/B45/2-EHN5 yielded the lowest mean overall RMS vibration, with a 37.5% reduction relative to neat diesel (D100), and the lowest equivalent sound level (LAeq) among the tested fuels. Under the investigated steady-state constant-load conditions, the D40/SCPO10/B45/2-EHN5 fuel blend demonstrates the potential to achieve lower measured vibration and noise levels than neat diesel. Full article

Rock fracture behavior is strongly influenced by grain size and boundary effects, which complicate the determination of fracture parameters and the interpretation of size-dependent failure. This study investigates the fracture behavior of sandstone and diorite within the framework of the boundary effect model (BEM) using three-point bending tests, acoustic emission (AE), and digital image correlation (DIC). By varying the prefabricated crack length, different values of the structural geometric parameters a_e were obtained, and the fracture toughness K_IC and tensile strength f_t were identified by regression analysis. The results show that K_IC = 0.6841 MPa·m^0.5 and f_t = 4.5625 MPa for sandstone, whereas K_IC = 2.7233 MPa·m^0.5 and f_t = 21.8218 MPa for diorite. Increasing the prefabricated crack length reduces the peak load and prolongs the pre-peak damage evolution stage. Diorite, with a larger average grain size, exhibits higher AE energy release, a higher proportion of high-energy AE events, and a larger fracture process zone (FPZ) than sandstone. Moreover, the AE energy distribution along the crack propagation direction shows a distinct “three-stage” characteristic, consistent with the non-uniform distribution of local fracture energy g_f predicted by boundary effect theory. The results indicate that BEM can reasonably characterize the fracture behavior of rocks with different grain sizes, and the identified material parameters can be used to construct a BEM-based structural failure curve for estimating nominal failure stress over a wider range of structural geometric parameters. Full article

The implementation of methanol-ammonia dual-fuel engines has the potential to contribute to a reduction in carbon emissions in the environment. The present study employs numerical simulations of the methanol-ammonia dual-fuel engine to investigate methanol direct injection pre-injection strategies. The impact of pre-main injection time interval and pre-injection quantity was investigated on output power, output torque, cylinder pressure and exhaust emissions such as NO_X, HC, CO, and CO₂. The results show that compared with the single methanol injection strategy, increasing the pre-injection strategy can effectively reduce soot emissions. Under certain pre-injection conditions, NO_X and soot emissions can also be significantly reduced. Compared with low pre-injection quantities, by using high pre-injection quantities, soot and NO_X emissions can be reduced by 36.91% and 35.31%, respectively. Under high pre-injection quantities, increasing the pre-main injection time interval can also significantly reduce NO_X emissions. Compared with the single methanol injection strategy, the pre-injection strategy leads to an increase in cylinder pressure peak and an advance in peak timing. As the pre-main injection time interval increases, both output power and output torque decrease. It is found that when the pre-injection quantity is 6 mg and the pre-main injection time interval is 25 °CA, with no substantial reduction in output power and output torque, the engine’s soot emissions can be reduced by 34.67%, and NO_X emissions can be reduced by 30.31%. Full article

The retrofit of existing residential buildings plays a critical role in reducing energy consumption and carbon emissions in the building sector. However, previous retrofit evaluations often fail to account for the age-related thermal and lighting requirements of residents in aging residential buildings, thereby overlooking the substantial behavioral heterogeneity that shapes retrofit effectiveness. This study evaluates the comprehensive performance of different building envelope retrofit strategies, considering occupants’ thermal and visual comfort, from the perspectives of energy efficiency, economic feasibility, and environmental sustainability. First, age-specific differences in occupancy patterns, thermal preferences, and lighting requirements between elderly and non-elderly comparison group occupants were systematically extracted from the literature. Then, a typical high-rise residential building was modeled in EnergyPlus to serve as the reference building, within which the differentiated occupant behavior models were implemented, and the pre-retrofit condition was defined as the baseline scenario. Next, six commonly applied exterior wall insulation materials and different glass configurations and window frames were parameterized and evaluated under varying insulation thicknesses and remaining building service life scenarios. Finally, the energy-saving performance, economic benefits, and carbon reduction potential of envelope retrofit measures were quantitatively assessed across three primary functional zones (bedroom, living room, and study), using area-normalized indicators. The results indicate that, in the retrofit of existing residential buildings, bedrooms and study rooms exhibit greater retrofit benefits than living rooms, primarily due to longer occupancy durations and higher heating demand. In terms of retrofit strategies, exterior wall insulation consistently outperforms window retrofitting in energy-saving potential, with energy-saving rates of approximately 3.2–4.3% depending on functional zone, material type, and insulation thickness. Among the evaluated materials, vitrified microbead insulation performs best overall in terms of energy, economic, and carbon benefits at 40–60 mm thickness. These findings support occupant-informed, low-carbon retrofit decision-making for existing residential buildings. Full article

The aim of the paper was to analyse the genesis of the idea of carbon footprint (CF) reporting, the current EU regulations in force in this regard, and to provide a concrete example of practical measures in poultry production. The CF is the total sum of greenhouse gas (GHG) emissions generated directly or indirectly by an organisation, product, service, event or human activity, expressed as a CO₂ equivalent. Livestock production accounts for 12% to 14.5% of global methane and nitrous oxide emissions. GHG emissions from livestock production are closely linked to the species of animals; the highest CF values apply to products derived from ruminants, but poultry is also considered an environmental threat, inter alia due to the production scale. The CF of poultry production is not uniform and depends on many factors, including the farm location and climatic conditions of the region, the profile of production, its stage, the birds feeding and CF method of analysis. Industrial development is a continuous process that must align with the principles of sustainability and EU climate policy; therefore, it is necessary to look for and implement solutions to reduce its emissions in line with evolving European legal standards. Full article

Oxy-fuel combustion is a near-zero emission technology that utilizes high-concentration O₂ in place of air, combined with recycled flue gas, to achieve efficient combustion and enable effective CO₂ capture. In this study, air (21% O₂/79% N₂) was used as the control atmosphere, and rice straw combustion experiments were conducted using thermogravimetric analysis and differential scanning calorimetry and differential scanning calorimetry coupled with mass spectrometry (TG-MS) at heating rates of 10, 20, and 30 °C/min under oxy-fuel conditions of 30% O₂/70% CO₂, 50% O₂/50% CO₂, and 70% O₂/30%CO₂. The combustion behavior, pollutant emissions, reaction kinetics, and underlying mechanisms were systematically evaluated. The results show that CO₂ in oxy-fuel atmospheres exhibits a higher thermal inertia, due to its greater density and specific heat capacity, thereby enhancing flame stability. Oxy-fuel atmospheres reduce the ignition temperature (Tᵢ) and burnout temperature (T_f), shorten the combustion duration, shift DTG and DSC peaks to lower temperatures, and result in sharper peaks along with an increased ignition index (Cᵢ), burnout index (C_b), and comprehensive combustion index (S). Mass spectrometry (MS) analysis reveals that oxy-fuel atmospheres combined with heating rates of 20–30 °C/min suppress O₂ diffusion and thermal NO formation, reducing NO_x emissions by over 75% and simultaneously inhibiting the release of SO₂ and COS. Kinetic analysis using the FWO and Friedman methods shows that the activation energy decreases from 210.5 kJ/mol and 219.1 kJ/mol under air conditions to 110.5 kJ/mol and 114.6 kJ/mol in oxy-fuel atmospheres, representing a reduction in reaction barriers of 47.5% and 47.7%, respectively. The reaction mechanisms were identified as three-dimensional diffusion-controlled processes at heating rates of 20–30 °C/min, and random nucleation followed by growth under high O₂ concentration conditions at a heating rate of 30 °C/min. Optimizing the combustion atmosphere and heating rate enhances the rice straw combustion efficiency and reduces pollutant emissions, thereby providing theoretical support for its clean and efficient utilization. Full article

Industrial-scale Anaerobic Digestion (AD) is a key technology for the energy recovery of agro-industrial and municipal waste and for the mitigation of greenhouse gas emissions; however, the actual operational performance of industrial biodigesters continues to show significant discrepancies with respect to the theoretical values reported in the scientific literature. In this context, there is still a lack of systematic analysis to identify which operating parameters are consistently monitored in industrial settings and which remain insufficiently explored, particularly those that describe the overall state of the digestion environment. To address this gap, a systematic literature review was conducted in the Scopus database for the period 2000–2026, complemented by a bibliometric analysis using VOSviewer software v1.6.18. 3. After applying inclusion criteria focused exclusively on industrial-scale and pilot systems, 1327 documents corresponding to the category of operating parameters were selected and analyzed using keyword co-occurrence networks and evaluation of occurrence frequencies and total link intensities. The analysis shows a marked concentration of the literature on a small set of classic parameters, highlighting pH (154 occurrences, 3667 link intensities), temperature (147 occurrences, 3255 link intensities), and ammonia (131 occurrences, 2824 link intensities) as the most recurrent variables in the industrial operation of anaerobic digesters. Complementarily, parameters such as chemical oxygen demand, total and volatile solids, and hydrogen sulfide have progressively increased their presence since 2015, mainly associated with effluent quality assessment, nutrient recovery, and overall process sustainability. In contrast, variables that integrate the state of the environment, such as electrical conductivity, oxidation-reduction potential, and the rheological properties of digestate, appear in less than $5\%$ of the studies analyzed, despite their ability to integrate information on stability, buffer capacity, and overall operating conditions. Taken together, these findings highlight an imbalance between the intensive use of traditional parameters and the limited incorporation of integrative indicators in industrial monitoring, suggesting that their systematic inclusion, together with the development of soft sensors and predictive models, could contribute to improving operational control and reducing the gap between the theoretical performance and actual behavior of industrial biodigesters. Full article

Light-based diagnostic and therapeutic approaches are increasingly important in modern biomedicine, with organic dyes emerging as versatile optical agents due to their tunable photophysical properties. Precise control over absorption and emission characteristics has enabled their application in fluorescence, photoacoustic, and Raman imaging, as well as in photodynamic and photothermal therapies. However, challenges related to biocompatibility, aqueous stability, and in vivo performance remain critical for clinical translation. Organic dyes that absorb in the near-infrared region are particularly attractive because of their deeper tissue penetration and reduced background interference. This review highlights key structure property relationships of organic dyes and summarizes current design strategies, including chromophore modification, peripheral functionalization for water solubility, and self-assembled nanotheranostic systems. Recent biomedical applications in cancer diagnosis and therapy, bacterial detection, and imaging-guided treatment are discussed, along with future directions for advancing dye-based technologies in healthcare. Full article

This study is based on time-series land use data of Xinjiang from 2000 to 2022. Using grid tools, bivariate autocorrelation models and other methods, we systematically analyzed the spatiotemporal variation characteristics of land use and ecosystem service value. The results show the following: Firstly, from 2000 to 2022, Xinjiang’s LUCC exhibits differentiated evolution characteristics: cropland, forestland, and built-up land expanded continuously, while the areas of grassland and unused land showed a steady reduction trend, and the area of water bodies showed a fluctuating growth pattern. Secondly, according to the calculation of carbon emissions from LUCC in Xinjiang from 2000 to 2022, the carbon emissions from LUCC have increased significantly, from 27.79 million tons in 2000 to 226.43 million tons in 2022, with built-up land being the main source of carbon emissions, but the continuous reduction in grassland area has led to the weakening of carbon sequestration capacity. Thirdly, from 2000 to 2022, Xinjiang’s ESV shows a fluctuating upward trend, increasing from 1880.528 billion yuan in 2000 to 1894.198 billion yuan in 2022, with grassland and water area being the core contributors to ESV, accounting for over 80% of the total contribution. Fourthly, in terms of spatial distribution, there is an overall negative correlation between the intensity of carbon emissions from LUCC and the intensity of ESV, mainly aggregated as “low–low” and “low–high”, with “high–low” aggregation primarily distributed in the desert areas of the Tarim Basin and Junggar Basin and “low–high” aggregation concentrated in the marginal mountainous areas and oasis regions of Xinjiang. The findings provide a solid scientific basis for the optimization of land use structure, the achievement of carbon emission reduction targets, and the protection of ecosystems in Xinjiang and similar arid regions worldwide. Full article