Search Results (2,938)

Tri-reforming of methane (TRM) has emerged as a promising pathway for low-carbon syngas production by integrating steam reforming, dry reforming, and partial oxidation within a single process. This coupling enables simultaneous CH₄ utilization and CO₂ valorization while enabling internal heat generation and flexible adjustment of the H₂/CO ratio for downstream synthesis. However, TRM performance cannot be adequately evaluated using conversion or energy efficiency alone, because the process involves complex interactions among competing reaction pathways, transport phenomena, catalyst stability, and thermodynamic irreversibility. This review provides a multiscale critical assessment of TRM from both first-law energy and second-law exergy perspectives, linking reaction-network fundamentals to reactor-level behavior and system-level performance. The literature evidence shows that although high temperatures and near-autothermal operation can enhance CH₄ conversion and reduce external heat demand, these conditions may simultaneously intensify deep oxidation, hotspot formation, carbon-forming tendencies, and exergy destruction. While equilibrium analyses help define feasible operating windows, they are insufficient without kinetic modeling and reactor-scale studies that capture spatial non-uniformities and pathway competition. Across reported TRM systems, exergy destruction is consistently concentrated within the reformer, identifying the reacting core as the dominant thermodynamic bottleneck. Accordingly, the key challenge in TRM is not simply to maximize conversion but to preserve chemical work potential while maintaining syngas quality and operational stability. Viewed from this perspective, TRM is better understood as an irreversibility-aware multiscale design problem in which optimal performance depends on the integrated optimization of catalyst functionality, reactor architecture, heat management, and system-level operation. Full article

Cement clinker production is a thermal- and emissions-intensive process requiring high-temperature heat for drying, calcination, and sintering. This review provides a process-based assessment of refuse-derived fuel (RDF), solid recovered fuel (SRF), tire-derived fuel (TDF), and biomass as partial substitutes for coal and petcoke in modern dry-process cement kilns. The study synthesized the evidence from plant-scale trials, pilot and laboratory experiments, process modeling, computational fluid dynamics, emissions studies, life-cycle assessment (LCA), techno-economic analysis (TEA), and regional case studies to evaluate alternative fuels across fuel properties, kiln-zone suitability, process stability, clinker quality, emissions performance, and environmental outcomes. The review shows that stable co-processing generally requires fuels with net calorific values above 14 MJ kg⁻¹ and moisture contents below 15%, although TDF can provide 26–33 MJ kg⁻¹ and sustain high-energy kiln duty when sulfur, zinc, and steel residues are controlled. RDF, SRF, and biomass require pre-processing, homogenization, calibrated dosing, and continuous fuel-quality monitoring to limit incomplete burnout, deposit formation, volatile circulation, and clinker-quality variation. LCA studies show that 20% RDF thermal substitution can reduce global warming potential by about 3.3–4.2%, increasing to approximately 6.7% when avoided landfill methane credits are included. Modern abatement systems can maintain particulate matter at about 10–30 mg Nm⁻³ and PCDD/F below 0.1 ng TEQ Nm⁻³ under stable operation. The review concludes that alternative fuels are quality-dependent co-processing options whose mitigation role is complementary to clinker-factor reduction, energy-efficiency improvement, low-clinker binders, electrified heating, oxy-fuel calcination, and carbon capture. Full article

Off-odor volatiles limit the acceptability of Atlantic salmon. This study investigated the effects of spatial distribution within the fillet, storage conditions, and cooking methods on the volatile profile of salmon and evaluated how pre-harvest rearing conditions, sex, and the presence of skin influence volatile compound formation during storage and cooking. Volatiles were classified as lipid-derived, protein-derived, and environmental contaminants. Spatial distribution within the fillet influenced volatile formation, with the head region exhibiting higher concentrations than the center and tail, reflecting differences in lipid distribution and precursor availability. During storage, fillets stored on ice generally exhibited higher volatile concentrations than samples frozen immediately, particularly for lipid-derived and environmental compounds, consistent with continued biochemical and microbial activity during chilled holding, whereas frozen storage preserved the biochemical state of the fillet. The magnitude of these differences depended on pre-harvest rearing conditions, the presence of skin, and harvest age. Cooking significantly increased volatile concentrations compared to raw fillets, with dry-heat methods, particularly baking, producing the highest levels, while boiling resulted in lower concentrations due to leaching into the cooking medium. Lower volatile formation was generally associated with cool-reared fish, male fillets, and muscle-only samples, while warm-reared, female, and skin-on samples exhibited greater volatile formation or retention, reflecting differences in precursor availability and tissue structure. These findings demonstrate that volatile formation in salmon is governed by the interaction between precursor accumulation during growth, spatial variability within the fillet, and transformation during post-harvest storage and cooking. Full article

Heat stress (HS) is at the top of the challenges facing modern dairy production, with annual losses according to global projections, under high-emission scenarios, reaching US$14.7–40.0 billion by the end of the century. This review emphasizes three interconnected topics that account for most of the proportion of the productive and reproductive losses during HS. First, the physiological consequences of HS are reviewed, with emphasis on the pair-fed thermal neutral (PFTN) paradigm, which established that reduced dry matter intake (DMI) accounts for only 35–50% of the observed milk yield decline, with the remainder arising from tissue-level effects of hyperthermia on mammary function, metabolism, and reproductive performance. Second, HS-induced microbiome disruption is examined as an active pathophysiological amplifier, whereby rumen dysbiosis compromises intestinal barrier integrity and drives systemic endotoxaemia, chronically amplifying the immune suppression already imposed by the thermal insult. Third, we focus on the integration of multi-omics platforms as a management approach, since single-omics analyses capture only a fraction of the biological complexity underlying the HS response. As the available datasets expand in coverage and scale, their integration through AI-driven analytical frameworks has the potential to substantially advance beyond the current fragmented picture, progressively building toward a systems-level model of thermal stress. Evidence-based mitigation strategies spanning environmental cooling, targeted nutritional supplementation, and genomic selection are critically evaluated within this framework, with emphasis on equity of access to evidence-based solutions across global dairy production systems. Full article

Wildfires significantly affect wood properties and usability, yet their impact on hardwood species remains insufficiently understood. This study presents an exploratory characterization of moderately fire-affected pedunculate oak (Quercus robur L.) wood, combining physical, mechanical, chemical, and thermal analyses to evaluate depth-related changes within outer stem zones. Samples were collected from bark and from wood originating approximately 1 cm and 1–2 cm beneath the cambial region to evaluate radial variation associated with moderate surface fire exposure. The oven-dry density of fire-affected wood reached 720 kg·m⁻³, corresponding to values marginally below the literature reference ranges reported for unaffected oak wood. Bending strength decreased to 85.56 MPa, while compressive strength remained within or marginally above the literature reference (71.16 MPa), and Brinell hardness (42.75 MPa) stayed within the typical range for oak. Chemical and elemental analyses revealed degradation of polysaccharides and carbon enrichment in surface layers. FTIR and DSC analyses suggested partial hemicellulose degradation, structural modification of cellulose, and reduced thermal reactivity in outer stem regions. Despite these changes, the higher heating value (19.09–19.56 MJ·kg⁻¹) remained within the literature reference ranges reported for oak wood. The results suggest that under moderate surface fire conditions, fire-induced changes were primarily concentrated in outer stem layers, while inner wood retained properties comparable to the literature reference values for unaffected oak wood. These findings indicate that moderately fire-affected oak wood may remain suitable for selected material or energy-related applications following appropriate quality assessment and removal of thermally altered surface zones. Full article

Sustainability in higher education plays a crucial role in shaping future professionals with an eco-conscious mindset. This study focuses on developing and simulating a portable solar food dehydrator as a practical application of sustainability principles in technology education. By integrating sustainability into the curriculum, this research enhances students’ technical skills while promoting the use of renewable energy and effective food preservation methods. Furthermore, the project aligns with green campus initiatives by encouraging energy-efficient practices and reducing food waste. This study emphasizes the significance of education for sustainable development by offering learners hands-on experience in designing eco-friendly solutions, promoting innovation, and equipping them to contribute to a more sustainable future. A food dehydrator is a device that removes moisture from food to aid in its preservation, utilizing a heat source and airflow to reduce its water content. The researchers used two methods to dehydrate food: direct sunlight (sun drying) and indirect sunlight (solar drying). The study used a developmental research design. Simulations revealed that, with solar-powered electricity, the longer the drying time, the greater the reduction in the moisture content. This was evident in the eighth experiment, which was conducted on fruits and vegetables. While drying with direct sunlight, the same trends, albeit to a lesser extent, were observed in the reduction in the moisture content of the fruits and vegetables. These insights can inform future design improvements, making the products more visually appealing and distinctive, thereby enhancing their attractiveness and novelty. Full article

The successful realization of a circular economy in the cement industry, coupled with a substantial reduction in carbon emissions, relies on the development of sustainable alternative binder systems. This study investigated the physicomechanical performance and sulfate resistance of composites produced by alkali activation of natural perlite and blast furnace slag. The aim of the research was to improve mechanical properties under low- and medium-alkalinity conditions (5–10 M NaOH). The samples were cured at an ambient temperature of 20 °C and then treated with heat at 60 °C. These samples were then mechanically processed and subjected to five soak–dry cycles in 5% and 10% Na₂SO₄ solutions. The results showed that heat treatment resulted in the formation of a dense C-A-S-H gel, increasing compressive strength approximately eightfold, from 11.64 MPa to 92 MPa. However, perlite’s porous and brittle structure limits its flexural strength to 0.27 MPa; this value is insufficient for structural applications. Under severe sulfate attack (10% Na₂SO₄), samples cured at ambient temperature showed a 12% mass increase in the first cycle due to solution infiltration into capillary voids. As a consequence of extensive ettringite and gypsum formation, the specimens experienced severe deterioration, resulting in a complete loss of mechanical integrity and a residual compressive strength of 0 MPa. In contrast, heat-treated samples showed limited ion diffusion due to a denser matrix and an improved aggregate interface transition zone, resulting in a 2.6% mass increase and a residual compressive strength of 5.17 MPa. Consequently, the obtained findings indicate that thermally treated alkali-activated slag–perlite composites exhibit high resistance against sodium sulfate attack and may have potential for use in specific industrial environments with high sulfate concentrations. However, the performance of these materials under more complex aggressive conditions, such as mining environments involving magnesium sulfate exposure and acidic drainage waters, should be further validated through future studies. Full article

Urban forests are widely promoted for improving air quality, yet their effectiveness is typically assessed through static green-space indicators that ignore seasonal variation in vegetation activity. This limitation is especially consequential in cold-region cities, where winter heating-season pollution peaks coincide with the leaf-off period of deciduous trees. Using a monthly panel of 15 centrally heated cities in northern China (2015–2024; N = 1464), this study develops a phenology-aware framework integrating three indicators: effective forest capacity (EFC), which combines dynamic forest area with a sigmoid leaf-on share and city-specific evergreen fraction; heating-season exposure (HI); and a binary phenology–heating mismatch (PHM) flag. City–year–month fixed-effects models show that the EFC–PM_2.5 association is directionally negative but statistically inconclusive under conservative inference (city-clustered SE: $p=0.523$; wild bootstrap: $p=0.541$), whereas associations with SO₂ and O₃ are statistically robust. The central empirical contributions are the four-quadrant heterogeneity analysis and the topographic paired comparison: four-quadrant heterogeneity analysis reveals that forest capacity shows clearer negative associations in dry semi-humid cities, whereas HI dominates in heating-dominated plain cities. A paired topographic comparison between Urumqi and Xining illustrates how terrain-induced inversions can override forest signals. The results support differentiated urban greening strategies that coordinate forest expansion with heating-system transition, evergreen species planning, and ventilation-sensitive urban design. Full article

Power batteries used in electric-powered vessels, new-energy tractors or construction machinery typically require prolonged, continuous operation at high power levels, which can lead to significant heat buildup and pose serious threats to battery safety, cycle life, and operational stability. Traditional air-cooled and liquid-cooled systems struggle to meet the requirements for efficient heat dissipation under heavy loads. Phase change materials (PCMs) are ideal for passive battery thermal management due to their high latent heat but are severely limited by low thermal conductivity and liquid leakage. In this study, nitrogen-doped carbon nanotubes@SiO₂ (PNT@SiO₂) were synthesized and further fabricated into oriented porous aerogels by directional freeze-drying using cellulose-based materials as the skeleton. Polyethylene glycol-8000 (PEG-8000) was loaded via vacuum impregnation to obtain the PSAP composite PCM. The optimized composite exhibits a thermal conductivity of 0.93 W/m·K, 3.2 times that of pure PEG, with 96% PEG loading and a phase change enthalpy of 158 J/g. Battery thermal management tests demonstrate its excellent temperature control and heat suppression performance. This study provides a high-performance and feasible thermal management solution for power batteries used in relevant fields. Full article

The European Union produces approximately 8 million tons (dry matter) of sewage sludge annually. Conventional management approaches, such as landfilling and incineration, pose significant environmental concerns, including greenhouse gas emissions and pollutant dispersion. This study evaluates the environmental sustainability of an innovative sludge recovery pathway, Hydrothermal Dewatering (HTD), developed and validated within the LIFE FREEDOM project. A Life Cycle Assessment (LCA) was conducted on a pilot plant treating 1000 tons of sewage sludge. The quantitative results reveal that the HTD process generates a total climate change impact of 8.95 × 10⁴ kg CO₂ eq per functional unit (1000 t). The heating and reaction phase represents the main environmental hotspot, accounting for 92.9% of the overall single-score impact. Crucially, comparative analyses indicate that the HTD process exhibits statistically comparable aggregated impacts to incineration and landfilling, while demonstrating distinct environmental advantages in specific midpoint categories. Furthermore, the assessment of the solid residue (HTD-cake) as a 10 wt% substitute for natural clay in brick manufacturing confirmed the absence of environmental burden shifting. Overall, the findings quantitatively validate HTD as a viable and competitive alternative to traditional end-of-life options. Full article

This paper examines a resource-saving technology for ferrosilicon smelting using industrial waste, specifically aluminum slag and aspiration dust from ferroalloy production. A technological approach is proposed based on the preliminary pelletization of finely dispersed aluminum slag to improve the physicochemical properties of the charge materials and ensure their efficient use in the metallurgical process. Pellets were produced by granulation in a disk granulator using a lignosulfonate binder, followed by drying and high-temperature firing in the temperature range of 600–800 °C. Microstructural and energy-dispersive analysis revealed the formation of a stable aluminosilicate matrix, represented predominantly by mullite-like phases, ferrosilicate inclusions, and calcium–magnesium silicates. The formation of these phases contributes to the strengthening of the pellet structure and the formation of intergranular bonds during heat treatment. Experimental ferrosilicon smelting was conducted in a laboratory ore-thermal electric arc furnace. The results demonstrated a stable electrothermal smelting regime, satisfactory charge layer gas permeability, and effective reduction processes. The resulting alloy corresponds to FS-45 ferrosilicon grade with a silicon content of approximately 48%. It was established that aluminum slag-based pellets actively participate in the formation of an aluminosilicate slag system of the SiO₂-Al₂O₃-CaO-MgO type, ensuring favorable slag physicochemical properties and efficient separation of the metallic and slag phases. The proposed approach enables the incorporation of industrial waste into metallurgical production, reducing the environmental impact, and increasing the resource efficiency of silicon ferroalloy production processes. Full article

Microwave (MW) ablation is a minimally invasive technique used to destroy pathological tissues through localized heating generated by a needle applicator. Internally cooled applicators using water circulation have long been the standard for high-power applications; however, water cooling introduces significant mechanical complexity. This work investigates the feasibility of a novel air-cooled coaxial thermal-ablation needle operating at 2.45 GHz up to 70 W. The system uses two concentric metal tubes—an outer 14 G stainless steel shaft (OD 2.1 mm) and an inner copper capillary (OD 1 mm, ID 0.7 mm)—serving simultaneously as the MW transmission line and cooling conduit, with dry air at room temperature (25 °C) flowing at 11 L/min under 5 bar input pressure. Experimental cooling efficiency tests demonstrated 78% efficiency for the shaft section in air and 32% for the section embedded in tissue. Electromagnetic and thermal simulations predicted ablation dimensions in a non-perfused liver of 35 mm short axis with ellipticity of 0.65 for the basic applicator, improving to 0.88 with an advanced PEEK-shaft design featuring a cancelling slot. A prototype was built and tested on exvivo bovine liver, achieving input matching better than −24 dB at 2.44 GHz and ablation dimensions (average of 5 tests) of 31 mm short axis and 45 mm long axis. Results confirm the feasibility of air cooling as a simpler, safer, and lower-cost alternative to water cooling for medium-power MW ablation. Full article

Mass transfer is central to food processing but remains difficult to quantify because food materials are heterogeneous, multiphase, porous, biologically structured, and dynamically changing. Under these conditions, experiments alone cannot fully capture the spatiotemporal complexity of transport behavior, making modeling and simulation essential for mechanism interpretation, process prediction, and engineering optimization. Existing reviews mainly address specific operations or numerical methods, with limited synthesis of governing equations, simulation workflows, application implementation, and practical applicability. This review examines food mass transfer by linking coupled momentum, heat, and mass transfer laws with governing equation selection, simulation workflow, and representative food processing applications. Governing formulations for Fickian diffusion, conservation-based transport, heat–mass coupling, multicomponent transfer, Darcy-type porous-medium flow, and related model extensions are summarized, together with their assumptions, geometric applicability, and dimensionless criteria. A unified simulation workflow is then organized, covering transport type identification, governing equation and physical model selection, geometric representation, parameter determination, initial and boundary condition specifications, numerical method and simulation tool selection, numerical implementation, validation, and transferability assessment. Representative applications are discussed for drying, heat–mass coupled processes, multicomponent transfer, transport in porous foods, and redistribution in multi-ingredient or multilayer foods. Overall, future progress requires more integrated, structure-aware, experimentally validated, transferable, and application-oriented simulation frameworks. Full article

Cities in climatic transition zones face coupled radiative and evaporative stresses, and their carbon emission mechanisms differ significantly from those in humid regions. Taking Xi’an, a typical megacity in the transition zone, as a case study, this research utilises a 500 m × 500 m grid to integrate multi-source data for carbon emission accounting. By applying spatial autocorrelation and the Multi-scale Geographically Weighted Regression (MGWR) model, this study examines the spatial heterogeneity of carbon emissions and the mechanisms through which urban planning influences them. The results indicate that carbon emissions in Xi’an exhibit a “core–periphery” agglomeration pattern, with commercial land use exhibiting the highest emission intensity. Carbon emissions and land surface temperature are spatially coupled, consistent with a hypothesised positive feedback loop of the “dry heat island” effect. Morphological factors exhibit spatial non-stationarity: floor area ratio is positively associated with emissions in the old city centre, whereas mutual shading among super-high-rise buildings in the High-Tech Zone coincides with a weaker effect. Building density shows a positive association only where ventilation is limited. Land use mix and blue–green spaces show non-linear negative associations with emissions, with higher marginal benefits in arid–hot environments. This study proposes carbon reduction strategies for the renewal of old urban areas, business cores, and new ecological districts, providing empirical evidence and decision-making references for low-carbon spatial planning in cities within the climatic transition zone. Full article

Earth–Air Heat Exchangers (EAHEs) are passive systems that use the thermal interaction between air and soil along buried ducts to moderate supply air temperature, thereby lowering building energy consumption and improving indoor comfort conditions. This device has been employed in several countries and under diverse climatic characteristics. The integration of EAHE systems with bioclimatic design strategies contributes to improved building energy performance and more efficient use of thermal resources. This study aims to computationally investigate the thermoenergetic performance of EAHE system, for both cooling and heating purposes, installed in Social Housing (SH) across different Brazilian bioclimatic zones, and to propose strategies that improve the energy efficiency of these built environments. The study involves the validation and verification of a computational model and the thermoenergetic assessments of an SH unit, investigating different solar orientations and the installation of EAHE. These evaluations are performed via dynamic simulations conducted with the EnergyPlus software. The results show that the installation of the EAHE system coupled to the SH improves the thermoenergetic performance of the indoor environment, mainly by enhancing thermal comfort across different Brazilian bioclimatic zones (BZ). In BZ2R, the EAHE increased the annual PHFT by 4.5%, corresponding to seventeen additional days per year within the acceptable operative temperature range. The highest monthly improvement was observed in BZ1M, where the PHFT increased by 14.3% in January, equivalent to more than four additional days of thermal comfort in that month. The system proved to be more effective in zones 1M, 2R, 3B, and 4B, particularly in climates with lower annual average dry-bulb temperatures. Regarding energy performance, the EAHE showed benefits in specific months and conditions, indicating that its feasibility should be assessed through monthly thermoenergetic analyses rather than only annual indicators. This work provides validated and verified references and parameters for future projects and contributes to the state of the art in this field, as there are still few studies evaluating EAHE systems integrated into buildings using this software, despite its widespread use in building performance analysis. Full article