Search Results (24,159)

Whole-plant corn silage is a critical feedstuff in global ruminant production, and its nutrient composition is closely tied to harvest timing. As starch acts as the primary energy source in silage-based diets, investigating changes in starch degradation rate provides a theoretical basis for optimizing the efficient utilization of whole-plant corn and its silage in ruminant production. In this study, whole-plant corn (harvested from the milk stage to full ripening stage) and its corresponding silage were used as experimental materials. An in vitro simulated rumen fermentation system was employed to determine the contents of starch, prolamin, amylose, and amylopectin in the samples. The results showed that with delayed harvest time, starch content in both whole-plant corn and its silage increased significantly; prolamin and amylose contents first decreased, then increased; amylopectin content first rose significantly before decreasing; and both starch disappearance rate and speed exhibited a trend of first increasing, then decreasing. After silage fermentation, the silage had significant increases in starch, amylose, and amylopectin contents, and starch disappearance rate; prolamin content decreased; and starch disappearance speed increased extremely significantly. This study indicates that whole-plant corn harvest time and silage fermentation regulate the ruminal starch degradation pattern by altering starch structure, prolamin content, and the proportion of rapidly degradable starch. Full article

Tool structure design methodologies predominantly rely on trial-and-error approaches or single-objective optimization but fail to achieve coordinated enhancement of multiple performance metrics while lacking thorough investigation into complex cutting coupling mechanisms. This study proposes a multi-objective optimization framework integrating joint simulation approaches. First, a finite element model for orthogonal turning was developed, incorporating the hyperbolic tangent (TANH) constitutive model and variable coefficient friction model. The cutting performance of four micro-groove configurations is comparatively analyzed. Subsequently, parametric modeling coupled with simulation–data interaction enables multi-objective optimization targeting minimized cutting force, reduced cutting temperature, and decreased wear rate. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) explores Pareto-optimized solutions for arc micro-groove geometric parameters. Finally, optimized tools manufactured via powder metallurgy undergo experimental validation. The results demonstrate that the optimized tool achieves significant improvements: a 19.3% reduction in cutting force, a 14.2% decrease in cutting temperature, and tool life extended by 33.3% compared to baseline tools. Enhanced chip control is evidenced by an 11.4% reduction in chip curl radius, accompanied by diminished oxidation/adhesive wear and superior surface finish. This multi-objective optimization methodology effectively overcomes the constraints of conventional single-parameter optimization, substantially improving comprehensive tool performance while establishing a reference paradigm for cutting tool design under complex operational conditions. Full article

This paper investigates the effects of Ti and Nb addition with varying Mn content on the solidification macrostructure and microstructure in the continuous casting slab of Q355 steel using optical microscopy, scanning electron microscopy, transmission electron microscopy, and electron probe microanalysis. The evolution of central segregation and MnS inclusions during thermal simulation compress deformation has been clearly established using Gleeble-1500 thermal simulation tester. The results indicate that by reducing the Mn content and adding a small amount of Ti and Nb, it is possible to refine the grain and mitigate the center segregation of Q355 steel. Mn steel with 1.25% Mn and without Ti and Nb addition exhibits the most severe center segregation. The TiNb steel with 0.52% Mn and a small amount of Ti and Nb addition showed a marked improvement in the center segregation of the slab. The Nb steel with 0.56% Mn and 0.009% Nb shows the presence of thin film ferrite along prior grain boundaries surrounded by Widmanstätten ferrite, and the central segregation has not shown significant improvement. The thermal simulation samples of the three steel types inherit the characteristics of their respective casting structures. Full article

Fiber-based black-and-white developing-out papers (DOPs) were among the most widely used photographic supports of the 20th century. Their broad use, structural complexity, and range of surface finishes, alongside evolving manufacturing practices, underscore the importance of understanding their material composition for authentication, dating, and conservation purposes. This study presents a multi-analytical characterization of three DOP sample sets: two from Ilford (ca. 1950) and one from Kodak (1972), complementing previous research with a deeper insight into general features, stratigraphy, and composition. Initial non-sampling techniques, including thickness measurements, colorimetry, optical microscopy, and UV–visible induced fluorescence, were used to classify papers into visually and physically distinct groups. This informed a targeted sampling strategy for further stratigraphic and compositional analysis using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS), X-ray fluorescence (XRF), Raman spectroscopy, and fiber/pulp identification tests. Significant differences were observed in base tint, surface gloss, optical brightening agents, fillers, and fiber content. Notable findings include the presence of iron (III) oxide–hydroxide pigment in Ilford cream papers, anatase titanium dioxide (TiO₂) in a baryta-less Ilford sample, and the shift to more uniform tones and mixed pulps in Kodak papers by the 1970s. These results offer valuable insights into historical manufacturing and support improved dating and characterization of photographic papers. Full article

Chemical Looping Combustion (CLC) technology has emerged as a promising approach for carbon capture owing to its CO₂ separation capability, which addresses the pressing challenge of global climate change. Although iron-based oxygen carriers offer economic advantages owing to their abundance and low cost, their limited cyclic stability restricts their industrial deployment. This study focused on optimizing the performance of iron-based oxygen carriers through composite modification with Al₂O₃ and TiO₂. Using Cantera (2.5.0) software and the minimum Gibbs free energy principle, conversion rates and product distributions of Fe₂O₃, Fe₂O₃/Al₂O₃, and Fe₂O₃/TiO₂ were systematically analyzed under varying temperatures (800–950 °C), oxygen carrier-to-fuel molar ratios (O/C = 1–15), and pressures (0.1–1.0 MPa). The optimal conditions were identified as 900 °C, O/C = 8, and 0.1 MPa. After 50 simulation cycles, Fe₂O₃/Al₂O₃ and Fe₂O₃/TiO₂ achieved average total reaction counts of 503 and 543, respectively, substantially exceeding 296 cycles for Fe₂O₃. The results indicated that Al₂O₃ and TiO₂ improved cyclic stability via physical support and structural regulation mechanisms, thereby offering a practical carrier composite modification strategy. This study provides a theoretical basis for the development of high-performance oxygen carriers and supports the industrial application of CLC technology for efficient carbon capture and emission mitigation. Full article

The aim of this study was to analyze the effect of finishing methods on the surface quality of Ti-6Al-4V titanium alloy additively manufactured by selective laser melting. It was observed that among the finishing methods, water jet treatment did not produce significant changes, while the abrasive water jet proved effective in removing defects and smoothing the surface, especially at a pressure of 30 MPa. However, the risk of abrasive particle entrapment in the material was observed. Promising results were also obtained using the water–ice jet, which combines effective material removal with surface smoothing. The selection of the finishing method should be tailored to the application requirements. Further research will focus on optimization and the combination of techniques to improve the functional properties of titanium components. Full article

Alongside the gradual progress of industrialization and the continuous development of human society, the problems of environmental pollution and energy crisis have become increasingly prominent. Semiconductor photocatalysis is a promising solution to these challenges. The photocatalytic reduction of CO₂ by TiO₂ to produce carbon monoxide and methane is a process which has been identified as a means of developing clean energy. In this paper, two-dimensional TiO₂ (2D-TiO₂) was synthesized via a one-step solvothermal method, and one-dimensional TiO₂ (1D-TiO₂) was obtained through a hydrothermal process. Their photocatalytic CO₂ reduction performances were systematically investigated. The results show that 2D-TiO₂ exhibits superior catalytic activity compared to 1D-TiO₂, which can be attributed to its lamellar structure, larger specific surface area, and improved hydrophilicity, providing more active sites and faster reaction kinetics. To further reveal the reaction mechanism, density functional theory (DFT) calculations were carried out using VASP with the GGA–PBE functional, PAW potentials, and a plane-wave cutoff energy of 520 eV. A 3 × 3 × 1 Monkhorst–Pack grid was used for Brillouin zone integration, and all possible adsorption configurations of CO₂*, COOH*, and CO* intermediates on the 2D-TiO₂ surface were evaluated. The results confirm that 2D-TiO₂ stabilizes key intermediates more effectively, thereby lowering the energy barrier and facilitating CO₂ reduction. These findings demonstrate that structural modulation of TiO₂ significantly influences its photocatalytic performance and highlight the great potential of 2D-TiO₂ for efficient CO₂ conversion and clean energy applications. Full article

Engineering phase-selective gel composites presents a promising route to enhance both CO₂ adsorption and conversion efficiency in photocatalytic systems. In this work, Cu₉S₅/TiO₂ gel composites were synthesized via a hydrazine-hydrate-assisted hydrothermal method, using TiO₂ derived from a microwave-assisted sol–gel process. The resulting materials exhibit a porous gel-derived morphology with highly dispersed Cu₉S₅ nanocrystals, as confirmed by XRD, TEM, and XPS analyses. These structural features promote abundant surface-active sites and interfacial contact, enabling efficient CO₂ adsorption. Among all samples, the optimized 0.36Cu₉S₅/TiO₂ composite achieved a methane production rate of 34 μmol·g⁻¹·h⁻¹, with 64.76% CH₄ selectivity and 88.02% electron-based selectivity, significantly outperforming Cu₉S₈/TiO₂ synthesized without hydrazine hydrate. This enhancement is attributed to the dual role of hydrazine: facilitating phase transformation from Cu₉S₈ to Cu₉S₅ and modulating the interfacial electronic environment to favor CO₂ capture and activation. DFT calculations reveal that Cu₉S₅/TiO₂ effectively lowers the energy barriers of critical intermediates (*COOH, *CO, and *CHO), enhancing both CO₂ adsorption strength and subsequent conversion to methane. This work demonstrates a gel-derived composite strategy that couples efficient CO₂ adsorption with selective photocatalytic reduction, offering new design principles for adsorption–conversion hybrid materials. Full article

Metal hydrides are an attractive way to store hydrogen in a compact and safe manner under low pressure. However, one of the hurdles to the widespread use of this method is the difficulty of the first hydrogenation, which increases the material cost. In this paper, we report the effect of substituting Zr with Ti in Zr_1−xTi_xCr₂ alloys (x = 0, 0.25, 0.5, 0.75, and 1) on the first hydrogenation. All the substituted alloys had similar microstructures and crystallized in the metastable C14 Laves phase. For x = 0, the first hydrogenation was possible at room temperature under 2 MPa of hydrogen pressure. As x increased, the hydrogen capacity decreased. For x = 0.75 and 1, first hydrogenation was practically impossible. Full article

The g-C₃N₄/ZnO nanocomposite materials were applied to degrade methylene blue (MB). The samples were characterized and evaluated to study the adsorption and photocatalytic degradation under visible light. The g-C₃N₄ was incorporated at percentages of 5%, 10%, 20%, and 40% relative to the ZnO weight. These composite materials were prepared using a solvothermal microwave technique. The structural, textural, morphological, and optical properties were investigated using XRD, FTIR, SEM, EDS, STEM, BET, UV-Vis, and XPS techniques. The XRD patterns of the samples showed the coexistence of crystalline phases of g-C₃N₄ and ZnO, while images and elemental composition analysis confirmed the formation of nanocomposite samples. The UV-Vis spectrum revealed a redshift in the absorption edge of the nanocomposites, indicating improved light-harvesting capability. The synthesized material g-C₃N₄/ZnO (20/80), with a surface area of 25 m²/g, exhibited higher photocatalytic performance, achieving 85% degradation of MB after 100 min under visible light, which corresponds to nearly three times the degradation efficiency of commercial P25-TiO₂ (31%) under the same conditions. The reusability and stability tests were conducted up to the fifth cycle, and this material showed 77% degradation, indicating good stability. This nanocomposite material has good potential as a photocatalyst for solar-driven MB. Full article

This research investigates the multi-objective optimization of micro-milling processes for the titanium alloy Ti-3Al-2.5V (grade 9) through the application of grey relational analysis. The incorporation of nanometer-sized particles in hybrid machining lubricants plays a crucial role in improving heat transfer during machining. The approach aims to increase the efficiency and effectiveness of micro-milling by addressing various performance metrics simultaneously, leading to better machining results for this titanium alloy. Additionally, the integration of nanoparticles into the machining lubricant significantly improves the lubrication properties, reducing friction during the machining process. The study analyzed four machining parameters: machining speed, rate of feed, axial depth of cut, and the weight percentage concentration of hybrid machining lubricants Multi-wall Carbon Nano Tube and Alumina Oxide (MWCNT and Al₂O₃). The machining nanolubricant was formulated by adding 1% and 2% volume concentrations of MWCNT and Al₂O₃ nanoparticles to the industrial machining fluid. In this machining context, the friction between the machining tool and the Ti-3Al-2.5V work piece is a vital factor influencing the output quality. The results demonstrate that the chosen machining parameters and machining lubricants have a direct impact on the coefficient of friction and surface roughness. The study concludes that utilizing machining nanolubrication for machining Ti-3Al-2.5V (grade 9) significantly enhances the quality compared with traditional machining lubricants. Full article

This study explores the cultural, productive, territorial, and organizational practices of cacao-producing families in Lebrija, Santander (Colombia), within the broader context of rural sustainability and peasant identity in Latin America. In response to recent national and international frameworks recognizing the rights of peasants, the research aims to document local knowledge systems and community-based strategies that sustain rural livelihoods. Through a qualitative ethnographic approach, including participatory workshops, semi-structured interviews, and social cartography, the study collected narratives, practices, and territorial dynamics over the course of one year. The results reveal that cacao production is not only an economic activity, but a deeply embedded cultural process that intertwines with memory, family ties, lunar cycles, and environmental stewardship. Participants described conflicts related to water access, deforestation, poultry farming, and the expansion of urban infrastructure. Despite these pressures, families demonstrated adaptive capacities through agrodiversity, traditional knowledge, and associative work. The study concludes that these cacao-based practices offer valuable insights into bottom-up strategies for resilience and territorial sustainability and calls for greater inclusion of peasant knowledge in rural development agendas. Full article

BaTi₅O₁₁ nanocrystals were synthesized via a sol–gel method employing different organic solvents. The influence of solvent choice on microstructure and photocatalytic performance was investigated through methylene blue (MB) degradation under UV light irradiation. The monoclinic BaTi₅O₁₁ nanocrystals were successfully synthesized, where solvent selection significantly affected their grain size and Brunauer–Emmett–Teller (BET) surface area. The BaTi₅O₁₁ nanocrystals synthesized using polyethylene glycol-200 (PEG-200) exhibited the highest BET surface area (9.78 m²/g) and smallest average pore size (17.8 nm). The BaTi₅O₁₁ nanocrystals also displayed a larger optical bandgap (3.61 eV), attributed to pronounced quantum confinement and surface effects. Consequently, the PEG-200-derived BaTi₅O₁₁ photocatalyst achieved complete MB degradation within 30 min under UV light irradiation. This enhanced performance was attributed to the high BET surface area providing abundant active sites. Furthermore, the BaTi₅O₁₁ nanocrystal photocatalyst maintained excellent reusability and stability over four consecutive cycles. Full article

This study assessed the impact of untreated wastewater discharge in the Danube River on four native fish species: barbel (Barbus barbus), vimba bream (Vimba vimba), perch (Perca fluviatilis), and white bream (Blicca bjoerkna). Biomarkers of exposure and effect were evaluated, including metal and metalloid bioaccumulation in gills, liver, and gonads, DNA damage (comet assay), chromosomal abnormalities (micronucleus assay), liver enzyme activities (ALT, AST), and erythrocyte maturation. White bream showed the highest genotoxic damage (TI% = 22.57), particularly in liver tissue, indicating high sensitivity to pollution. Perch had elevated DNA damage in blood (TI% = 22.69) and strong biomarker responses, likely due to its predatory behavior. Barbel displayed notable DNA damage in gills (TI% = 30.67) and liver (TI% = 20.35), aligning with sediment exposure due to its benthic habits. Vimba bream had the lowest responses, possibly reflecting reduced exposure or resilience. Element accumulation varied across tissues and species, with perch showing the highest overall levels. Hepatic enzyme activities (highest values: ALT = 105.69 in barbel; AST = 91.25 in white bream) and changes in erythrocyte profiles supported evidence of physiological stress. Integrated Biomarker Response (IBR) analysis identified white bream as the most sensitive species, followed by perch and barbel. These results emphasize the value of multi-species biomonitoring and the importance of species-specific traits in freshwater ecotoxicology. Full article

The infestation of boktor (Xystrocera festiva Pascoe) stem borer in Sengon (Falcataria falcata) tree plantations in Indonesia, especially in Java, has caused severe losses by damaging the stems, decreasing wood quality, and potentially leading to mortality. To digest the woods, the X. festiva larvae’s gut has at least two digestive enzymes, which are trypsin and α-amylase. Former studies have shown that F. falcata produces inhibitors of these two enzymes as part of its defense mechanisms. This research aimed to analyze trypsin inhibitor (TI) and α-amylase inhibitor (AAI) transcripts, as well as their expression, in X. festiva-infested and resistant F. falcata trees. We found 19 contigs encoding the TI gene and 29 contigs encoding AAI. The results were able to predict the sequence of the DNA that produced the TI and AAI transcriptomes, which proved that one gene could be expressed differently due to alternative splicing. The DEG analysis and RT-PCR confirmed that mostly the TI and AAI activity was heavily induced by the X. festiva larvae attacks. The expression of the TI gene was upregulated 0.78 times, while the AAI gene expression was upregulated 2.44 times in infested samples. The findings from this study are fundamental in understanding the mechanism of F. falcata resistance against X. festiva infestation and selecting the resistant trees. Full article