Search Results (2,075)

The blending of hydrogen significantly impacts the diffusion and safety characteristics of natural gas within indoor environments. This study employs ANSYS Fluent 2021 R1 to numerically investigate the diffusion and ventilation characteristics of hydrogen-blended natural gas (HBNG) leakage in indoor spaces. A physical and mathematical model of gas leakage from pipelines is established to study hazardous areas, flammable regions, ventilation characteristics, alarm response times, safe ventilation rates, and the concentration distribution of leaked gas. The effects of hydrogen blending ratio (HBR), ventilation conditions, and space dimensions on leakage diffusion and safety are analyzed. Results indicate that HBNG leakage forms vertical concentration stratification in indoor spaces, with ventilation height being negatively correlated with gas concentration and flammable regions. In the indoor space conditions of this study, by improving ventilation conditions, the hazardous area can be reduced by up to 92.67%. Increasing HBR substantially expands risk zones—with pure hydrogen producing risk volumes over five times greater than natural gas. Mechanical ventilation significantly enhances indoor safety. Safe ventilation rates escalate with hydrogen content, providing quantitative safety criteria for HBNG implementation. The results underscore the critical influence of HBR and ventilation strategy on risk assessment, providing essential insights for the safe indoor deployment of HBNG. Full article

The circular economy in construction requires the valorization of gypsum waste from construction and demolition. Waste from gypsum plasterboards is considerable, yet it is still viewed more as a problem than as a mineral resource. This study investigates the potential for utilizing recycled gypsum (RG) from waste plasterboards in the production of blended green binders. Four gypsum–cement–pozzolanic binders are designed with two pozzolanic additives (natural zeolite and recycled brick powder) in two ratios to cement—0.6 and 1.0. The structural mineral compounds of the binders are analyzed by XRD and DTA/TG, while the performance of both fresh and hardened paste is evaluated by standardized methods for binders to determine possible construction applications of these green binders. Results show that RG can be used to produce blended fast-setting binders with a gypsum content of above 40%. Systems with natural zeolite achieve higher strength (up to 30 MPa at 90 days) and sufficient water resistance, thus suitable even as substitutes for cement binders. The developed blended binders with recycled brick powder can be used in low-moisture environments only as substitutes for gypsum binders in plasters, masonry units, and lightweight composites. Full article

Objectives: The impact of combining animal and plant protein sources on digestibility is unclear, despite their increasing clinical use. Using a non-invasive dual stable isotope tracer approach, we assessed the digestibility, bioavailability and utilization of distinct protein blends in older adults, and associated plasma amino acid profiles and muscle protein synthesis (MPS) rates. Methods: Thirty-two older men (69 ± 3 y) consumed one of four protein blends (A (51:49, casein/soy); B and C (35:25:20:20, whey/casein/soy/pea); D (80:20, casein/whey)) alongside primed constant infusions of [1,2-¹³C₂] leucine for 8 h. Arterialized blood and vastus lateralis muscle biopsies were collected during a trickle feed protocol with all blends providing 20 g total protein, universally labeled ¹³C-spirulina, and ²H-cell free amino acid mix to determine digestibility. This trial was registered at Clinicaltrials.gov (ID-NCT07038655). Results: No differences (¹³C:²H ratios) were found in digestibility between the protein blends (p > 0.05). Mean (±SEM) fed state MPS at 2.5 h was 0.078 ± 0.009%/h, 0.075 ± 0.012%/h, 0.085 ± 0.007%/h and 0.065 ± 0.011%/h for drinks A, B, C and D, respectively, with a main time effect observed (p < 0.01), but no significant differences between drinks. Plasma essential amino acids (EAAs) increased significantly from baseline for all blends by 40 min (p < 0.05), with no differences between blends at any time point. Conclusions: These findings suggest that protein quantity (and/or leucine content), rather than composition, appears to be the most important factor driving MPS. Future work should focus on clinical populations where protein requirements and digestibility characteristics may differ. Full article

This study examined engine combustion characteristics of the plastic diesel produced through pyrolysis of waste plastics as an eco-friendly source of engine fuel. We extensively measured and compared the key fuel properties based on various diesel fuel standards. Distillation and hydrotreatment processes were used to improve the quality of the pyrolysis oil, resulting in distilled plastic diesel (DPD) and hydrotreated plastic diesel (HPD). DPD and HPD were blended at 10:90 and 20:80 (vol%) ratios with commercial diesel, resulting in fuel blends termed as DPD10, DPD20, HPD10, and HPD20, respectively, to analyse their engine combustion characteristics. A full-scale 4-cylinder, 4-stroke diesel engine was used in this study. There are virtually no studies available in the literature where engine combustion characteristics have been tested with both distilled and hydrotreated plastic pyrolytic oil. This study comprehensively investigated the combustion behaviours of all four fuel blends under full-load conditions and at an engine operating speed of 1500 rpm, except engine exhaust gas temperature which was measured at varying engine speeds from 1200 rpm to 2400 rpm at an interval of 300 rpm. The study found notable differences in engine combustion characteristics between the commercial diesel and plastic diesel blends under identical operating conditions. The HPD blends had higher exhaust gas temperatures (EGTs) than the DPD blends, particularly at lower blend ratios, whereas the DPD10 and HPD10 blends had higher peak cylinder pressures than DPD20 and HPD20. The HPD10 blend exhibited the highest heat release rate (HRR) of 120.41 J/°CA. The engine combustion characteristics using a full-scale engine with distilled and hydrotreated plastic diesel and their comparison are not fully studied in the literature yet. Full article

In this paper, paraffin-44H (PW-44H) and paraffin-5 (PW-5) were respectively selected as the high/low-temperature phase change core material, and expanded vermiculite (EVM) was selected as the phase change carrier matrix. A high-temperature composite phase change material (CPCM), 44H/EVM, and a low-temperature CPCM, 5/EVM, were prepared by combining melt blending with vacuum adsorption. Nano-TiO₂ was incorporated as a thermal conductor into the CPCMs to enhance the heat transfer efficiency between the CPCM and asphalt. The heat storage performance, chemical stability, microstructure, and thermal stability of the two CPCMs were studied. The results show that when the dosage of nano-TiO₂ is 2%, the critical temperature range and heat storage performance of the CPCMs reach the optimum. Among them, the enthalpy value of the phase transition of the high-temperature PCM 44H-nTiO₂/EVM is 150.8 J/g, and the phase transition occurs over a temperature range of 37.3 °C to 45.9 °C. The enthalpy value of the phase transition of the low-temperature PCM 5-nTiO₂/EVM is 106.6 J/g, and the phase transition range is −7.9–0.4 °C. Moreover, the incorporation of nano-TiO₂ increased the thermal conductivity of the high- and low-temperature CPCMs by 47.2% and 51.6%, respectively. Finally, the high- and low-temperature CPCMs were compounded in a 1:1 ratio and mixed into asphalt to obtain a composite double PCM asphalt. The heat storage performance of the original sample asphalt and the double phase change asphalt was investigated by DSC, DSR, and an environmental chamber. The results show that when the dosage of PCM is 20%, compared with the original asphalt, the high-temperature extreme value and the low-temperature extreme value of the double phase change asphalt are reduced by 3.4 °C and 2.1 °C, respectively. The heating rate and cooling rate decreased by 8.5% and 5.6%, respectively, and the rheological properties can meet the requirements of the specifications. It can be seen that the addition of double PCMs can effectively slow down the heating/cooling rate of asphalt, thereby improving the temperature sensitivity of asphalt. Full article

Background/Objectives: Despite the advantages of polycaprolactone (PCL) for drug delivery, it still lacks effective approaches to enhance its encapsulation of drugs. Blending PCL with less hydrophobic polymers can tailor physicochemical properties to overcome these limitations. This study, for the first time, integrates two beneficial approaches—polymer blending and Box–Behnken design (BBD) optimisation—to develop PCL-based blend nanoparticles (NPs) with enhanced encapsulation efficiency (EE), controlled particle size, and improved stability through surface charge modulation. Methods: Drug-loaded blend NPs were developed using a double emulsion method, with different polymer ratios. A BBD model was employed to investigate the influential factors that control the size, charge, and EE. Results: Blending PCL with a less hydrophobic polymer significantly improved EE, achieving 60.96% under optimal conditions. The BBD model successfully predicted conditions for obtaining NPs with optimum size, negative charge, and enhanced drug encapsulation. The drug amount was identified as the most influential factor for EE, while polymer amounts significantly impacted size and charge. Conclusions: Careful control of polymer ratios, drug amount, and surfactant levels was shown to significantly influence particle size, surface charge, and EE, with the balanced 50:50 PCL:PLGA blend achieving optimal physicochemical performance. Using the BBD, the study identified the predicted optimal formulation consisting of 162 mg polymer blend, 8.37 mg drug, and 8% surfactant, which is expected to yield NPs with a size of 283.06 nm, zeta potential of −31.54 mV, and EE of 70%. The application of BBD allowed systematic evaluation of the factors and their interactions, providing robust predictive models. Full article

Engine knock remains a critical limitation in spark-ignition engine design. Future hybrid powertrains employ downsized engines operating on Atkinson cycles, creating different knock conditions compared to modern naturally aspirated or turbocharged engines. At the same time, petroleum-based gasoline is increasingly being replaced by biofuels and electrofuels. This study evaluates knock behavior in projected hybrid engine architectures and examines the chemical composition of emerging fuel blends. The analysis shows that hybrid engines benefit from fuels with lower sensitivity, defined as the difference between the Research and Motor Octane Numbers. This is because the higher end-gas temperatures associated with the Atkinson cycle shift the value of K, which is an interpolation factor used to capture the relationship between fuel sensitivity and anti-knock performance. In conventional engines, K is negative, favoring fuels with higher sensitivity. In hybrid engines, the increased engine temperatures result in K becoming positive, favoring low-sensitivity fuels. Using low-sensitivity fuels allows hybrid engines to operate with higher geometric compression ratios and advanced thermodynamic cycles while reducing knock constraints. Biofuels and electrofuels can meet these requirements by producing paraffinic and naphthenic hydrocarbons with high octane quality and low sensitivity. These findings emphasize the need to align renewable fuel development with hybrid engine requirements to improve thermal efficiency, reduce emissions, and reduce reliance on energy-intensive refinery processes for octane enhancement. Full article

Electrospun fibers serve as a medium for the targeted release of active compounds, facilitating the desired therapeutic effects in drug administration. The point of this study was to find the best conditions for making electrospun fibers from cellulose acetate (CA) and poly(ε-caprolactone) (PCL), mixed with pure oxyresveratrol extract from Artrocarpus lakoocha Roxberg (Moraceae). Additionally, the study focused on evaluating the antioxidant properties, antityrosinase activity, and freeze–thaw stability of the resulting fibers. We incorporated a concentration of oxyresveratrol at 0.1% w/w into various mass ratios of CA/PCL blended fiber sheets (1:0, 3:1, 1:1, 1:3), utilizing mixed solvents of acetone/DMF (2:1% v/v) and chloroform/DMF (9:1% v/v) for preparation. The fiber sheets displayed a continuous and uniform structure, with fiber diameters ranging from 300 to 1000 nanometers. We investigated the release kinetics of oxyresveratrol from the fibrous substrates using the total immersion technique, specifically in phosphate-buffered saline at a pH of 7.4. The results showed that the fiber sheet with a 3:1 w/w ratio of CA to PCL and a 0.1 w/w loading of oxyresveratrol showed the most significant release of oxyresveratrol at the 2 h mark, and it continued to release consistently at this peak value for up to 24 h. The antioxidant and anti-tyrosinase properties of oxyresveratrol in fiber sheets were more stable than those of free oxyresveratrol at the same concentrations. The fiber sheet presents a promising avenue for a user-friendly transdermal patch application. Full article

Different composites of polyethylene and two fillers (ignimbrite dust and Arundo donax fibers) were obtained by rotational molding. Both fillers were also combined among them to produce hybrid composites. The blends, prepared by dry-blending, were later rotomolded to determine the effect of such fillers into the tensile properties of the materials, before and after subjecting them to accelerated weathering on a UV chamber for up to 500 h. No significant differences are observed in the mechanical behavior of the different sample series, regardless their type or ratio of filler (5 or 10% by weight), due to the modifications only taking place on the sample surface and the rotomolded items having a thickness of nominally 4 mm. The carbonyl index was obtained from the FTIR spectra, determining an increase in this parameter with irradiation time. The samples with the Arundo fibers exhibit a lower carbonyl index, showing the potential stabilization effect of this lignocellulosic filler against UV, while the composites with the mineral powder tend to increase the oxidation of the samples when included at high loadings (10%). Full article

Recent studies have shown that using conventional plastics to produce disposable tableware significantly impacts the environment. Alternatively, using cellulosic pulp from harnessing agro-industrial wastes, such as mango, provides a unique opportunity to create eco-friendly and biodegradable disposable tableware, a high-volume single-use item. Cellulosic pulp from the tegument of mango (cultivar Tommy Atkins) was successfully obtained by a semichemical pulping process to manufacture biodegradable plates. Refining times of 0, 5, 10, and 15 min were tested, and it was observed that a refining time of 10 min yielded a notably stronger material of 2.15 km in breaking length. Moreover, when the mango fibers were blended with pine fibers in a 70:30 (mango/pine) ratio, the material’s porosity significantly improved from 0 to 0.60 s/100 cc air. Alkyl ketene dimer at 1.5% was incorporated to impart water-resistant properties, changing the contact angle drop test from 0 to >120°. The biodegradation test indicated that the samples achieved a significant biodegradation level of 62.14 and 67.65 after 182 days of testing. The results demonstrated that the tegument from mango agro-industrial waste has the potential to be a source of cellulosic pulp to produce biodegradable and disposable tableware, contributing to the decrease in the use of conventional plastics. Full article

Hydrogen-assisted fatigue cracking presents a critical challenge to the structural integrity of legacy carbon steel natural gas pipelines being repurposed for hydrogen transport, posing a major barrier to the deployment of hydrogen infrastructure. This study systematically evaluates the fatigue crack growth (FCG) behavior of API 5L X60 pipeline steel under varying hydrogen–natural gas (H₂–NG) blending conditions to assess its suitability for long-term hydrogen service. Experiments are conducted using a custom-designed autoclave to replicate field-relevant environmental conditions. Gas mixtures range from 0% to 100% hydrogen by volume, with tests performed at a constant pressure of 6.9 MPa and a temperature of 25 °C. A fixed loading frequency of 8.8 Hz and load ratio (R) of 0.60 ± 0.1 are applied to simulate operational fatigue loading. The test matrix is designed to capture FCG behavior across a broad range of stress intensity factor values (ΔK), spanning from near-threshold to moderate levels consistent with real-world pipeline pressure fluctuations. The results demonstrate a clear correlation between increasing hydrogen concentration and elevated FCG rates. Notably, at 100% hydrogen, API X60 specimens exhibit crack propagation rates up to two orders of magnitude higher than those in 0% hydrogen (natural gas) conditions, particularly within the Paris regime. In the lower threshold region (ΔK ≈ 10 MPa·√m), the FCG rate (da/dN) increased nonlinearly with hydrogen concentration, indicating early crack activation and reduced crack initiation resistance. In the upper Paris regime (ΔK ≈ 20 MPa·√m), da/dNs remained significantly elevated but exhibited signs of saturation, suggesting a potential limiting effect of hydrogen concentration on crack propagation kinetics. Fatigue life declined substantially with hydrogen addition, decreasing by ~33% at 50% H₂ and more than 55% in pure hydrogen. To complement the experimental investigation and enable predictive capability, a modular machine learning (ML) framework was developed and validated. The framework integrates sequential models for predicting hydrogen-induced reduction of area (RA), fracture toughness (FT), and FCG rate (da/dN), using CatBoost regression algorithms. This approach allows upstream degradation effects to be propagated through nested model layers, enhancing predictive accuracy. The ML models accurately captured nonlinear trends in fatigue behavior across varying hydrogen concentrations and environmental conditions, offering a transferable tool for integrity assessment of hydrogen-compatible pipeline steels. These findings confirm that even low-to-moderate hydrogen blends significantly reduce fatigue resistance, underscoring the importance of data-driven approaches in guiding material selection and infrastructure retrofitting for future hydrogen energy systems. Full article

The increased consumption of apparel has resulted in a corresponding increase in the volume of waste textiles, with polyester–cotton blended textiles accounting for as much as 80% of the total. However, extant recycling methodologies are beset by challenges, including high cost and difficulty in separation. Mycelium has been shown to possess the ability to degrade complex components in culture substrates. The present study explores the feasibility of using polyester–cotton yarn as a substrate for mycelium composite materials, thus offering an innovative approach to the treatment of waste blended textiles. Five mycelium composite materials with varying polyester–cotton ratios were prepared and tested for mechanical strength, moisture resistance, and biodegradability. ANOVA analysis confirmed that all properties of the mycelium composites were significantly influenced by the polyester–cotton matrix ratio, with partial eta-squared (ηp²) exceeding 84% across all properties. The most significant effect was observed in compressive strength (ηp² > 99%). Experiments identified a 65:35 polyester–cotton ratio as yielding optimal comprehensive properties: namely, a compressive strength of 0.221 MPa and flexural strength of 0.791 MPa, coupled with excellent moisture resistance and biodegradability. This provides data support for the development of textile-based mycelium composite products. In light of the aforementioned performance studies and material characteristics, the development of three series of experiential home products was undertaken. Design evaluations were conducted to explore the potential application of mycelium composites, which could have significant implications for promoting sustainable development in the textile and apparel industry and advancing innovative designs for mycelium composite materials. Full article

This study investigated the effects of homolactic fermentation on the rheological, viscoelastic, and starch structural properties of quinoa–chickpea flour-based beverages. Three formulations with increasing proportions of chickpea flour (10, 25, and 50%) were fermented for 10 h with Lactobacillus acidophilus LA-5. Apparent viscosity, deformation capacity, storage modulus (G′), and pasting behavior were measured along with FTIR-based analysis of the starch molecular structure. All fermented samples reached pH values < 4.5 and exhibited improved rheological properties with significant increases in viscosity and storage modulus (G′), particularly in the 50:50 blend. These enhancements were attributed to the synergistic effects of homolactic fermentation and inherent properties of chickpea starch, particularly its high amylose content, large granule size, and long amylopectin chains. FTIR analysis revealed that the short-range molecular order of starches was preserved after fermentation in all beverages, except for the 50:50 blend, as evidenced by the increased degree of order (DO) and double helix (DD) ratios. Overall, these findings demonstrate that integrating chickpea flour and controlled homolactic fermentation is an effective strategy for tailoring the viscosity and stability of plant-based probiotic beverages, providing a theoretical basis for the development of clean-label and functional fermented plant-based systems. Full article

Alkali-activated materials (AAMs) offer a promising low-carbon alternative to Portland cement, but their development has been dominated by fly ash and slag, whose availability is increasingly limited. This research explores waste brick powder (WBP) and metakaolin residue (RN), two abundant yet underutilized by-products, as blended precursors for sustainable binder design. The novelty lies in demonstrating how complementary chemistry between crystalline-rich WBP and amorphous RN can overcome the drawbacks of single-precursor systems while valorizing construction and industrial residues. Pastes were prepared with varying WBP/RN ratios, activated with alkaline solutions, and characterized by Vicat setting tests, isothermal calorimetry, XRD with Rietveld refinement, MIP, SEM, and mechanical testing. Carbon footprint analysis was performed to evaluate environmental performance. Results show that WBP reacts very rapidly, causing flash setting and limited long-term strength, whereas the incorporation of 30–50% RN extends setting times, sustains dissolution, and increases amorphous gel formation. These changes refine the formed reaction products, leading to compressive strengths up to 39 MPa and flexural strengths of 8 MPa at 90 days. The carbon footprint of all blends remained 392–408 kg CO₂e/m³, thus providing about a 60% improvement compared to conventional Portland cement paste. The study establishes clear design rules for waste-derived blended precursors and highlights their potential as circular, low-carbon binders. Full article

The persistence of the synthetic plastic waste problem makes it one of the most pressing environmental challenges. Sustainable material is an alternative approach to reduce petroleum plastics. In this research, our work aims to convert two biomaterials, water hyacinth (WH) and cassava chip (CC), into value-added biopolymer composite sheets (BCS). The raw materials of both WH and CC were prepared and characterized using physical and chemical treatments. Alkali treatments and chemical modifications were applied to remove lignin, protein, lipid, and other inhibiting components. After that, the two main raw materials of the WH and CC components were varied (100:0, 90:10, 80:20, 70:30, and 60:40, respectively) to investigate the optimal conditions for mixing, blending, and forming processes. Finally, mechanical properties (tensile strength), physical properties (surface morphology using a scanning electron microscope (SEM), crystalline structure by X-ray diffraction (XRD), and water solubility were also evaluated. The results obtained obviously revealed that the BCS reached an optimal ratio of 80:20 and exhibited outstanding properties. We were successful in exploring the potential use of a combination of two kinds of biopolymers under optimal conditions to produce an effective and environmentally friendly BCS in a manner that promotes a sustainable bio-circular economy and zero-waste concepts. Full article