Search Results (342)

Semen cryopreservation is associated with sperm vulnerability to oxidative stress and ice crystal-induced damage, adversely affecting in vitro fertilization (IVF) success. This study aimed to investigate the effects of freezing diluent supplemented with antioxidant limonin (Lim), myo-inositol (MYO), and the ice crystal formation inhibitor L-proline (LP) through sperm motility, morphological integrity, and antioxidant capacity. The Lim (150 mM), MYO (90 mM), and LP (100 mM) significantly ameliorated the quality of post-thaw sperm in Debao boar, and combined treatment of these agents significantly enhanced sperm motility, structural integrity, and antioxidant capacity compared with individual agents (p < 0.05). Notably, the combined use of these agents reduced glycerol concentration in the freezing diluent from 3% to 2%. Meanwhile, the integrity of the sperm plasma membrane, acrosome membrane, and mitochondrial membrane potential was significantly improved (p < 0.05), and the result of IVF revealed the total cell count of the blastocysts was also greater in the 2% glycerol group (p < 0.05). In conclusion, the newly developed freezing diluent for semen, by adding Lim (150 mM), MYO (90 mM), and LP (100 mM), can enhance the quality of frozen–thawed Debao boar sperm and reduce the concentration of glycerol from 3% to 2% as high concentrations of glycerol can impair the quality of thawed sperm and affect in vitro fertilization outcomes. In conclusion, the improved dilution solution formulated demonstrated efficacy in enhancing the quality of porcine spermatozoa following cryopreservation and subsequent thawing. Full article

Reinforced concrete structures are prone to the development of microcracks during service. In this study, a composite-modified epoxy potting adhesive was formulated using nano-TiO₂, carboxyl-terminated butadiene nitrile liquid rubber (CTBN), and the reactive diluent D-669. The mechanical properties and effectiveness of this composite adhesive in repairing oblique cracks were systematically evaluated and compared with those of single-component-modified epoxy adhesives. Key material parameters influencing the performance of oblique crack repair were identified, and the underlying repair mechanisms were analyzed. Based on these findings, a theoretical formula for calculating the shear-bearing capacity of beams with repaired web reinforcement was proposed. Experimental results demonstrated that compared to single-component-modified epoxy resin, the optimally formulated composite adhesive improved the tensile strength, elongation at break, and bond strength by 4.07–21.16 MPa, 13.28–20.4%, and 1.05–3.79 MPa, respectively, while reducing the viscosity by 48–872 mPa·s. The viscosity of the adhesive was found to play a critical role in determining the repair effectiveness, with toughness enhancing the crack resistance and bond strength contributing to the structural stiffness recovery. The adhesive effectively penetrated the steel–concrete interface, forming a continuous bonding layer that improved energy dissipation and significantly enhanced the load-bearing capacity of the repaired beams. Full article

Supercritical combustion is a promising technique for improving the efficiency and reducing the emissions of next-generation gas turbines. However, accurately modeling combustion under these conditions remains a challenge, particularly due to the complexity of chemical kinetics. This study aims to evaluate the applicability of a reduced global reaction mechanism compared to the detailed Foundational Fuel Chemistry Model 1.0 (FFCM-1) when performing hydrogen combustion with supercritical carbon dioxide and argon as diluents. Computational fluid dynamics simulations were conducted in two geometries: a simplified tube for isolating chemical effects and a combustor with cooling channels for practical evaluation. The analysis focuses on the evaluation of velocity, temperature, and the water vapor mass fraction distributions inside the combustion chamber. The results indicate good agreement between the global and detailed mechanisms, with average relative errors below 2% for supercritical argon and 4% for supercritical carbon dioxide. Both models captured key combustion behaviors, including buoyancy-driven flame asymmetry caused by the high density of supercritical fluids. The findings suggest that global chemistry models can serve as efficient tools for simulating supercritical combustion processes, making them valuable for the design and optimization of future supercritical gas turbine systems. Full article

Hollow fibre renewal liquid membranes (HFRLMs) are susceptible to third-phase formation during rare earth element (REE) extraction using D2EHPA (bis(2-ethylhexyl phosphoric acid)), potentially leading to membrane fouling and decreased mass transfer efficiency. This study investigated the effects of various parameters, such as the composition of the aqueous feed and organic phases, on the third-phase formation and limiting organic concentration (LOC) of REE(III) in D2EHPA. Higher concentrations of REEs and a higher pH in the feed phase correlated with decreased mass transfer, while yttrium showed a greater propensity to induce third-phase formation compared to other REEs. Conditions favouring the use of linear aliphatic diluents, low extractant concentrations (5–10 v/v% D2EHPA) and the absence of modifiers also contributed to third-phase formation. The addition of tri-n-butyl phosphate (TBP) mitigated third-phase formation without evidence of synergy with D2EHPA. These findings provide key insights into formulating extraction systems that prevent third-phase formation in HFRLM processes. Full article

Ignition delay time (IDT) is a critical parameter for evaluating the autoignition characteristics of aviation fuels. However, its accurate prediction remains challenging due to the complex coupling of temperature, pressure, and compositional factors, resulting in a high-dimensional and nonlinear problem. To address this challenge for the complex aviation kerosene RP-3, this study proposes a multi-stage hybrid optimization framework based on a five-input, one-output BP neural network. The framework—referred to as CGD-ABC-BP—integrates randomized initialization, conjugate gradient descent (CGD), the artificial bee colony (ABC) algorithm, and L2 regularization to enhance convergence stability and model robustness. The dataset includes 700 experimental and simulated samples, covering a wide range of thermodynamic conditions: 624–1700 K, 0.5–20 bar, and equivalence ratios φ = 0.5 − 2.0. To improve training efficiency, the temperature feature was linearized using a 1000/T transformation. Based on 30 independent resampling trials, the CGD-ABC-BP model with a three-hidden-layer structure of [21 17 19] achieved strong performance on internal test data: R² = 0.994 ± 0.001, MAE = 0.04 ± 0.015, MAPE = 1.4 ± 0.05%, and RMSE = 0.07 ± 0.01. These results consistently outperformed the baseline model that lacked ABC optimization. On an entirely independent external test set comprising 70 low-pressure shock tube samples, the model still exhibited strong generalization capability, achieving R² = 0.976 and MAPE = 2.18%, thereby confirming its robustness across datasets with different sources. Furthermore, permutation importance and local gradient sensitivity analysis reveal that the model can reliably identify and rank key controlling factors—such as temperature, diluent fraction, and oxidizer mole fraction—across low-temperature, NTC, and high-temperature regimes. The observed trends align well with established findings in the chemical kinetics literature. In conclusion, the proposed CGD-ABC-BP framework offers a highly accurate and interpretable data-driven approach for modeling IDT in complex aviation fuels, and it shows promising potential for practical engineering deployment. Full article

This experimental study examines the particle-level combustion behavior of high-volatile bituminous coal and walnut shell particles in oxyfuel environments, with a particular focus on the gas-phase ignition characteristics and the structural development of volatile flames. Particles with similar size and shape distributions (a median diameter of about 126 µm and an aspect ratio of around 1.5) are combusted in hot flows generated using lean, flat flames, where the oxygen mole fraction is systematically varied in both CO₂/O₂ and N₂/O₂ atmospheres while maintaining comparable gas temperatures and particle heating rates. The investigation employs a high-speed multi-camera diagnostic system combining laser-induced fluorescence of OH, diffuse backlight-illumination, and Mie scattering to simultaneously measure the particle size, shape, and velocity; the ignition delay time; and the volatile flame dynamics during early-stage volatile combustion. Advanced detection algorithms enable the extraction of these multiple parameters from spatiotemporally synchronized measurements. The results reveal that the ignition delay time decreases with an increasing oxygen mole fraction up to 30 vol%, beyond which point further oxygen enrichment no longer accelerates the ignition, as the process becomes limited by the volatile release rate. In contrast, the reactivity of volatile flames shows continuous enhancement with an increasing oxygen mole fraction, indicating non-premixed flame behavior governed by the diffusion of oxygen toward the particles. The analysis of the flame stand-off distance demonstrates that volatile flames burn closer to the particles at higher oxygen mole fractions, consistent with the expected scaling of O₂ diffusion with its partial pressure. Notably, walnut shell and coal particles exhibit remarkably similar ignition delay times, volatile flame sizes, and OH-LIF intensities. The substitution of N₂ with CO₂ produces minimal differences, suggesting that for 126 µm particles under high-heating-rate conditions, the relatively small variations in the heat capacity and O₂ diffusivity between these diluents have negligible effects on the homogeneous combustion phenomena observed. Full article

The production of very-low-sulfur residual fuel oil is a great challenge for modern petroleum refining because of the instability issues caused by blending incompatible relatively high-sulfur residual oils and ultra-low-sulfur light distillates. Another obstacle in the production of very-low-sulfur residual fuel oil using hydroprocessing technology is the contradiction of hydrodesulfurization with hydrodemetallization, as well as the hydrodeasphaltization functions of the catalytic system used. Therefore, the production of very-low-sulfur residual fuel oil by employing hydroprocessing could be achieved by finding an appropriate residual oil to be hydroprocessed and optimal operating conditions and by controlling catalyst system condition management. In the current study, data on the characteristics of 120 samples of heavy fuel oils produced regularly over a period of 10 years from a high-complexity refinery utilizing H–oil vacuum residue hydrocrackers in its processing scheme, the crude oils refined during their production, the recipes of the heavy fuel oils, and the level of H–oil vacuum residue conversion have been analyzed by using intercriteria and regression analyses. Artificial neural network models were developed to predict the characteristics of hydrocracked vacuum residues, the main component for the production of heavy fuel oil. It was found that stable very-low-sulfur residual fuel oil can be manufactured from crude oils whose sulfur content is no higher than 0.9 wt.% by using ebullated bed hydrocracking technology. The diluents used to reduce residue viscosity were highly aromatic FCC gas oils, and the hydrodemetallization rate was higher than 93%. Full article

Improving the manufacturability of drug formulations via direct compression has been of great interest for the pharmaceutical industry. Selecting excipients plays a vital role in obtaining a high-quality product without the wet granulation processing step. In particular, for diluents which are usually present in a larger amount in a formulation, choosing the correct one is of utmost importance in the production of tablets via any method. In this work, we assessed the possibility of manufacturing a small-molecule drug product, omeprazole, which has been historically manufactured via a multi-step processes such as wet granulation and multiple-unit pellet system (MUPS). For this purpose, four prototypes were developed using several diluents: a co-processed excipient (Microcelac^®), two granulated forms of alpha-lactose monohydrate (Tablettose^® 70 and Tabletose^® 100), and a preparation of microcrystalline cellulose (Avicel^® PH102) and lactose (DuraLac^® H), both of which are common excipients without any enhancement. The tablets were produced using a single punch tablet press and thoroughly characterized physically and chemically in order to assess their functionality and adherence to drug product specifications. The direct compression process was used for the manufacturing of all proposed formulations, and the prototype formulated using Microcelac^® showed the best results and performance during the compression process. In addition, it remained stable over twelve months under 25 °C/60% RH conditions. Full article

Porous materials are used in many important applications, such as separation technologies, catalysis, and chromatography. They may be obtained from various monomers via diverse polymerization techniques and a wide range of synthesis parameters. The study is devoted to the synthesis and characterization of crosslinked porous polymeric spheres containing pyrrolidone subunits. To achieve this goal, two methods were applied: direct synthesis from N-vinyl-2-pyrrolidone (NVP) with ethylene glycol dimethacrylate (EGDMA) and via a modification reaction of porous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) with pyrrolidone (P). The polymerization was carried out with the use of different molar ratios of the monomers. In order to obtain highly porous materials, pore-forming diluents (toluene, dodecane, and dodecan-1-ol) were used. The synthesized copolymers were characterized using size distribution analysis, ATR-FTIR spectroscopy, scanning electron microscopy, thermogravimetry, and inverse gas chromatography. Determined by the nitrogen adsorption/desorption method, the specific surface area was in the range of 55–468 m²/g. The good thermal properties of the poly(VP-co-EGDMA) copolymers allowed them to be applied as the stationary phase in gas chromatography. Full article

Water-capped tailings technology (WCTT) is a strategy where oil sand tailings are sequestered within a mined-out pit and overlayed with a layer of water in order to sequester tailings with the aim that the resulting pit lake will support aquatic plants and organisms over time. The Base Mine Lake Demonstration (BML) is the first full-scale demonstration of a pit lake in the Athabasca Oil Sands Region (AOSR). In the BML, the release of methane from the fluid tailings influences several key processes, including the flux of greenhouse gases, microbial oxygen consumption in the water column, and ebullition-facilitated transport of organics from the fluid tailings to the lake surface. It is hypothesized that the residual low molecular weight hydrocarbons (LMWHCs) derived from diluent naphtha used during bitumen extraction processes are the carbon sources fueling ongoing microbial methanogenesis within the BML. The aims of this study were to identify the LMWHCs in the BML fluid tailings, to elucidate their sources, and to assess the extent of biogeochemical cycling affecting them. A headspace GC/MS analysis identified 84, 44, and 56 LMWHCs (C4–C10) present in naphtha, unprocessed bitumen ore, and fluid tailings, respectively. Equilibrium mass balance assessment indicated that the vast majority (>95%) of LMWHCs were absorbed within residual bitumen rather than dissolving into tailings pore water. Such absorbed compounds would not be readily available to in situ microbial communities but would represent a long-term source for methanogenesis. Chromatographic analysis revealed that most biodegradable compounds (n-alkanes and BTEX) were present in the naphtha but not in fluid tailings or bitumen ore, implying they are sourced from the naphtha and have been preferentially biodegraded after being deposited. Among the LMWHCs observed in bitumen ore, naphtha, and fluid tailings, C2-cyclohexanes had the highest relative abundance in tailings samples, implying their relatively high recalcitrance to in situ biodegradation. Full article

Cured-in-place pipe (CIPP) technology is a trenchless rehabilitation method for damaged pipelines in which a resin-saturated liner (often a fiber-reinforced type) is inserted into a host pipe and cured in situ, typically using a UV light beam or steam. This study investigates the influence of selected photoreactive diluents on the photopolymerization process of a styrene-free vinyl ester resin designed for the CIPP applications by evaluating the rheological properties, photopolymerization kinetics (photo-DSC), thermal characteristics (DSC), crosslinking density (gel content), and mechanical properties of thick (15 mm) UV-cured layers. The tested diluents included monofunctional (i.e., methyl methacrylate and vinyl neodecanoate), difunctional (1,6-hexanediol diacrylate, aliphatic urethane acrylates, and an epoxy acrylate), and trifunctional monomers (trimethylolpropane triacrylate, pentaerythritol triacrylate, and trimethylolpropane ethoxylate triacrylate). The key findings demonstrate that the addition of pentaerythritol triacrylate (the most attractive diluent) increases the flexural strength (+6%) and deflection at strength (+28%) at the unchanged flexural modulus value (ca. 2.1 GPa). The difunctional epoxy acrylate caused an even greater increase in the deflection (+52%, at a 5% increase in the flexural strength). Full article

This study aimed to investigate the effects of adding different levels of punicalagin or oleuropein to TRIS diluent on the quality of frozen–thawed semen from Najdi rams. Semen was diluted using TRIS-based diluter with 15% egg yolk (control group); supplemented with 0.1, 0.5, or 1 mg/100 mL punicalagin (in Experiment 1); or supplemented with 1, 2.5, or 5 mg/100 mL oleuropein (in Experiment 2). The collected semen was evaluated and cryopreserved, with the motility and concentration of sperm assessed using a CASA system. The results showed that the total motile spermatozoa (TMS), percentage of progressive motile spermatozoa (PMS), curvilinear velocity (VCL), rectilinear velocity, average path velocity (VAP), linearity coefficient, straightness index, minor defects, and sperm vitality were higher in the 0.1 mg/100 mL punicalagin group (p < 0.05) than in other groups. HOST% post-thawing was significantly higher in all punicalagin groups compared to the control group (p < 0.001). The percentages of PMS, TMS, VCL, minor defects, and sperm vitality were higher in the 1 mg/100 mL oleuropein group (p < 0.05) than in other groups. Oleuropein supplementation at 5 mg/100 mL decreased VAP in cooled sperms, while all levels increased VAP post-thawing. HOST-positive sperms% post-thawing was higher in all oleuropein-treated groups than the control group (p < 0.001). Moreover, oleuropein nonsignificantly increased the acrosome integrity in cooled sperms, while higher studied concentrations of oleuropein (2.5 and 5 mg/100 mL) decreased the acrosome integrity in frozen sperms. In conclusion, adding punicalagin (0.1 mg/100 mL) or oleuropein (1 mg/100 mL) to TRIS diluent improved the quality of frozen–thawed semen from rams. Full article

Surface-enhanced Raman scattering (SERS) spectroscopy is an ultra-sensitive analytical method with the powerful signal-molecule detection capability. Coupling with the polydimethylsiloxane (PDMS) material, SERS can be enabled on a polymeric substrate for fast-developing bio-compatible sensing applications. However, due to PDMS’s high viscosity, conventional PDMS-SERS substrates are typically thick and stiff, limiting their freedom for engineering flexible micro/nano functioning devices. To address this issue, we propose to adopt a low viscosity decamethylcyclopentasiloxane (D5) solvent as a diluent solution. Via controlling the mixture ratio of D5 and PDMS and the spin-coating speed for deposition, this method resulted in a film of a well-defined thickness from sub-millimeter down to a 100 nm scale. Furthermore, thanks to the unsaturated Si-H chemical bonds in the PDMS curing agent, the PDMS film could effectively reduce the $A{g}^{+}$ ions to Ag nanoparticles (NPs) directly bonding onto the substrate surface uniformly. Via adjusting the size and density of the AgNPs through reaction temperature and time, strong SERS was achieved and verified using R6G with the detection limit down to 0.1 ppm, attributed to the AgNPs’ plasmonic enhancement effect. Full article

Penaeus monodon (black tiger shrimp) is one of the important shrimp species in aquaculture. Cryopreserving its sperm not only provides technical support for breeding but also effectively prevents the decline of genetic resources, promoting the sustainable development of its aquaculture industry. This study screened different types of diluents, cryoprotectants, and concentrations and explored equilibration time, cooling protocols, and thawing conditions, ultimately determining the optimal cryopreservation protocol for P. monodon sperm. The results showed that the optimal cryopreservation protocol involved using natural seawater as the diluent with 10% dimethyl sulfoxide (DMSO) as the cryoprotectant, in which the sperm suspension and cryoprotectant were mixed at a 1:1 (v/v) ratio and equilibrated at 4 °C for 30 min. Subsequently, cooling was performed using a programmable controlled-rate freezer: the temperature was reduced to −20 °C at −5 °C/min and held for 5 min; then cooled to −80 °C at −10 °C/min and held for 5 min; finally, the temperature was reduced to −180 °C at −20 °C/min. After cooling, the sperm samples were transferred to liquid nitrogen for long-term storage. The results demonstrated that thawing in a 37 °C water bath achieved the highest sperm motility compared to conditions at 27 °C, 32 °C, 42 °C, and 60 °C. After 15 days of liquid nitrogen storage, the sperm survival rate was 53.33 ± 9.18%. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that the sperm structure was intact before freezing, with a rounded head, a distinct acrosomal spike anterior to the head, a concentrated nucleus in the head, dense chromatin, and a smooth cell membrane surface. However, after freezing and thawing, the acrosomal spikes of some sperm were fractured, and the membrane structure was damaged. Enzyme activity analysis showed that during liquid nitrogen storage from 0 to 15 days, the enzyme activity of alkaline phosphatase (AKP) and acid phosphatase (ACP) in sperm gradually increased with significant differences observed compared to day 0 (p < 0.05). The activity of malondialdehyde (MDA) showed a gradual increase at 0, 5, and 10 days, but then decreased at day 15. The enzyme activity of catalase (CAT) showed no significant changes from 0 to 10 days (p > 0.05) but significantly increased on day 15 (p < 0.05). The activity of total superoxide dismutase (T-SOD) showed no significant changes from 0 to 5 days (p > 0.05) but significantly increased from days 10 to 15 (p < 0.05). These findings provide valuable insights into the cryopreservation of P. monodon sperm and will guide the optimization of cryoprotectant combinations and freezing protocols aimed at improving sperm survival rates. Full article

The low resistance of boar sperm to cryopreservation dictates that adding antioxidants and energetic substances to the diluent to improve sperm quality is necessary. This study is designed to assess the impact of various concentrations of safflower polysaccharides (SPSs; 0, 0.5, 1.0, 1.5, and 2.0 g/L) on the quality of boar sperm following freezing and thawing. The results of the study showed that the supplementation of 1.5 g/L SPS significantly enhanced the motility, average path velocity, straight-line velocity, curvilinear velocity, beat cross frequency, acrosome integrity, plasma membrane integrity, mitochondrial activity, and DNA integrity compared with the control group (p < 0.05). In addition, the supplementation of 1.5 g/L SPS significantly enhanced the total antioxidant capacity, superoxide dismutase activity, glutathione peroxidase activity, and catalase activity while significantly decreasing malondialdehyde and hydrogen peroxide content (p < 0.05). Therefore, the supplement SPS has potentially positive implications for improving the quality of cryopreserved boar sperm, and the recommended concentration is 1.5 g/L SPS. Full article