Search Results (52,784)

Using the quenching process to create a specific residual stress distribution in steel parts is a key method for improving their strength. Although finite element simulation can overcome the time-consuming and labor-intensive limitations of experimental measurements, accurately predicting the residual stress distribution in quenched steel parts remains a challenge for researchers and manufacturers. The initial yield strength weighting scheme used in finite element simulations has a significant impact on the results. To investigate the influence of initial yield strength weighting on the residual stress distribution in quenched steel cylinders, finite element models with different yield strength weightings have been developed. The results show that the large hardness difference between austenite and martensite can cause significant deviations between the residual stress predicted using linear weighting and the experimental results. The linear weighting scheme commonly used by researchers overestimates the yield strength of the austenite phase in the mixed-phase material during cooling, leading to an overestimation of residual stress. Employing nonlinear yield strength weightings, such as Leblond weighting, can significantly improve the computational accuracy of finite element models, yielding more reliable and consistent predictions. This improved accuracy in predicting residual stress using finite element simulation offers a powerful tool for optimizing the quenching process. Full article

Tropical cyclones are known to have significant ecological impacts, particularly on marine productivity. This study investigates the effects of two tropical cyclones (TC “MARIA” and TC “AMPIL”) on changes in environmental factors and phytoplankton in overlapping marine areas during August 2024. Our findings indicated that TC “MARIA”, despite its lower wind speeds, resulted in significant increases in surface chlorophyll-a (Chl-a) due to its prolonged duration, while depth-integrated Chl-a showed a declining trend, suggesting limitations on phytoplankton growth due to water column instability and reduced light availability. In contrast, TC “AMPIL”, with its higher wind speeds and faster translation speed, caused more immediate disturbances, leading to increases in surface Chl-a. However, the depth-integrated Chl-a did not significantly increase, as phytoplankton growth was hindered by the succession of the two typhoons. Additionally, we observed a pronounced cooling in sea surface temperature after both typhoons, likely linked to ongoing mixing processes and atmospheric influences. This study can provide us with more insights into the interaction between tropical cyclone dynamics and marine ecology. Full article

The regional imbalance of power supply and use is an important factor affecting the efficient and sustainable development of China’s power system. It is necessary to achieve the better matching of power supply and use through the optimization of the national power network layout. From a mathematical point of view, the power network layout’s optimization is a typical mixed-integer non-linear programming problem. The present paper proposes a novel method based on the Random Walk algorithm with Compulsive Evolution for China’s power network layout optimization to improve the network economy. In this method, the length of transmission lines and the amount of cross-regional power transmission between nodes are synchronously optimized. The proposed method was used to find the minimum total cost (TC) of the power transmission network on the basis of energy supply and use balance. The proposed method is applied to the optimization of power network of different scales. Results indicated that, compared with the optimization method that only optimizes the transmission line length, the TC of municipal and provincial power grids can be significantly reduced by the recommended methods. Moreover, for the national power network, through simultaneous optimization, the TC savings in 30 years of operation are significant. Full article

Background/Objectives: Hearing loss in childhood is associated with significant challenges in linguistic and cognitive development, particularly affecting language skills such as syntax, semantics, and pragmatics, which are essential for effective communication and social integration. This study aimed to analyze how different types and degrees of hearing loss impact linguistic development in children, and to identify clinical factors—such as age at diagnosis and years of language intervention—that may predict language performance. Methods: This study included a sample of 140 children aged 6 to 12, categorized into seven groups based on their hearing condition: unilateral and bilateral conductive, unilateral and bilateral sensorineural, unilateral and bilateral mixed hearing loss, and a control group with no hearing loss. Linguistic development was assessed using the Clinical Evaluation of Language Fundamentals-5 (CELF-5), a validated tool for diagnosing language disorders. Statistical analyses, including MANOVA and multiple regression, were conducted to evaluate differences in linguistic skills across groups and to determine the predictive value of clinical variables on total language performance. Results: The analysis revealed statistically significant differences across groups in all assessed linguistic domains (p < 0.001), with children with severe or bilateral hearing loss exhibiting notably lower scores compared to normohearing peers. The multiple regression analysis indicated that type of hearing loss was the strongest predictor of total linguistic performance (β = −0.674), followed by age at diagnosis (β = −0.285) and age of hearing device adaptation (β = −0.220). Years of language intervention also contributed significantly (β = 0.198) but to a lesser extent. Conclusions: This study highlights the critical impact of early and comprehensive auditory and language intervention on linguistic outcomes for children with hearing impairments. Early diagnosis and timely adaptation of hearing aids or cochlear implants are essential in mitigating language deficits, particularly in areas like syntax and pragmatic skills. These findings support the need for specialized, long-term interventions tailored to the severity and type of hearing loss to improve language development in this population. Full article

The formulation of binary, ternary, and quaternary supplementary cementitious materials (SCMs) on an optimized silica fume amount using fly ash, ultrafine (MQ), and limestone powders (LS) is the most sustainable approach to recycling these types of solid wastes for durable concrete. The optimum replacement level of 10% silica fume was blended with different replacement levels of 5, 8, 10, and 15% MQ to formulate different ternary mixes to evaluate the filling effect of MQ. Different ternary mixes containing 10% silica fume and 5, 10, and 15% LS were also produced to examine the effectiveness of both ternary mixtures with either MQ or LS. The quaternary mixtures with 10% silica fume optimized with 20% fly ash and 10% MQ or 10% LS were evaluated for compressive strength, chloride permeability, and porosity. The MQ showed the best filling effect compared to LS. The hot curing conditions significantly enhanced the performance of ternary and quaternary mixtures. Two effects of fillers were observed: the diluting effect brought on by replacement levels and the enhanced filling effect. At early curing, the strength loss resulting from the high replacement level was around 39%; however, this drop could be minimized to approximately 7% under hot curing conditions. It has been demonstrated that the binary, ternary, and quaternary systems offer the best solution to the environmental and durability issues caused by cement. The economic analysis highlights that optimized HPC mixtures with SCMs and fillers, particularly the quaternary mix, achieve superior cost-efficiency and mechanical performance, demonstrating their potential for sustainable and high-performance engineering applications. Full article

Large-scale epidemiological studies on the association of blood lead levels with blood pressure and hypertension prevalence are still limited, particularly among lead-exposed workers. The evidence is even more scarce on the interaction of blood lead levels with occupational variables and ambient air pollution levels. We developed mixed-effect models based on a large group of lead-exposed workers (N = 22,002). The results were also stratified by multiple groupings. Compared to participants with blood lead < 20 μg/L, those with levels > 20 μg/L had a 26–37% higher prevalence of hypertension, as well as a 0.65–13.7mmHg higher systolic and diastolic blood pressure. Workers exposed to high PM10 levels had a 21–28% higher risk. Workers exposed to high temperatures had a 0.41–2.46 mmHg greater increase in blood pressure, and those not exposed to dust had a 1.29–1.65 mmHg greater blood pressure increase. Our findings suggested the negative impact of blood lead on blood pressure and the prevalence of hypertension, with workers exposed to high PM10 concentrations, those exposed to occupational high temperature, and those without dust exposure being more vulnerable. Full article

Linear mixed models (LMMs) are commonly used in genome-wide association studies (GWASs) to evaluate population structures and relatedness. However, LMMs have been shown to be ineffective in controlling false positive errors for the analysis of resistance to Columnaris disease in Rainbow Trout. To solve this problem, we conducted a series of studies using generalized linear mixed-model association software such as GMMAT (v1.4.0) (generalized linear mixed-model association tests), SAIGE (v1.4.0) (Scalable and Accurate Implementation of Generalized mixed model), and Optim-GRAMMAR for scanning a total of 25,853 SNPs. Seven different SNPs (single-nucleotide polymorphisms) associated with the trait of resistance to Columnaris were detected by Optim-GRAMMAR, four SNPs were detected by GMMAT, and three SNPs were detected by SAIGE, and all of these SNPs can explain 8.87% of the genetic variance of the trait of resistance to Columnaris disease. The heritability of the trait of resistance to Columnaris re-evaluated by GMMAT was calibrated and was found to amount to a total of 0.71 other than 0.35, which was seriously underestimated in previous research. The identification of LOC110520307, LOC110520314, and LOC110520317 associated with the resistance to Columnaris disease will provide us more genes to improve the genetic breeding by molecular markers. Finally, we continued the haplotype and gene-based analysis and successfully identified some haplotypes and a gene (TTf-2) associated with resistance to Columnaris disease. Full article

In this work, we have investigated the thermal features of hydrogen peroxide-based energetic materials formulations. Initial research has shown that both the auxiliary oxidiser (sodium nitrate, potassium nitrate or calcium nitrate) and sensitising agent (glass microspheres) have significant influence on the rate of hydrogen peroxide decay in such formulations. In terms of the thermal features of the tested energetic materials, a similar and significant influence of the auxiliary oxidising agent and sensitising agent choice was observed. We have established that the use of calcium nitrate as an auxiliary oxidising agent (at ambient temperature of approx 20 °C), which allows the formulations to maintain capacity to undergo detonation for longer under storage conditions, negatively impacts the qualitative characteristics of the mixture as an energetic material. The thermal effects accompanying chemical interaction are much smaller than mixtures containing potassium and sodium nitrates as additional oxidising agents. Another important conclusion is that glass microspheres as sensitising agents significantly impact the thermal decomposition processes of the investigated on-site mixed (OSM) energetic material (EM) samples, except for the mixture using calcium nitrate. Full article

Based on the thermal phase structure of pure SU(2) quantum Yang–Mills theory, we describe the electron at rest as an extended particle, a droplet of radius $r_0\sim a_0$, where $a_0$ is the Bohr radius. This droplet is of vanishing pressure and traps a monopole within its bulk at a temperature of $T_c=7.95$ keV. The monopole is in the Bogomolny–Prasad–Sommerfield (BPS) limit. It is interpreted in an electric–magnetically dual way. Utilizing a spherical mirror-charge construction, we approximate the droplet’s charge at a value of the electromagnetic fine-structure constant $\alpha$ of ${\alpha }^{-1}\sim 134$ for soft external probes. It is shown that the droplet does not exhibit an electric dipole or quadrupole moment due to averages of its far-field electric potential over monopole positions. We also calculate the mixing angle ${\theta }_{\mathrm{W}}\sim {30}^{\circ }$, which belongs to deconfining phases of two SU(2) gauge theories of very distinct Yang–Mills scales (${\Lambda }_{\mathrm{e}}=3.6$keV and ${\Lambda }_{\mathrm{CMB}}\sim {10}^{-4}$eV). Here, the condition that the droplet’s bulk thermodynamics is stable determines the value of ${\theta }_W$. The core radius of the monopole, whose inverse equals the droplet’s mass in natural units, is about 1% of $r_0$. Full article

This paper presents a bandpass filter (BPF) exploiting hybrid shielded eighth-mode circular substrate-integrated waveguide (SD-EMCSIW) and complementary split ring resonator (CSRR) resonators. The proposed BPF leverages the SD-EMCSIW resonator with a 45-degree angle to create a second-order BPF with a mixed electromagnetic coupling scheme. Detailed analyses of the related electromagnetic characteristics and operating mechanisms have been performed. In order to further reduce the occupied area, the CSRR structures are embedded into the SD-EMCSIW resonators. Meanwhile, extra metallic via-holes are implemented to enhance the upper-stopband performance. A transmission zero (TZ) of the second-order BPF can be placed on either the left or right side of the passband and can be flexibly adjusted. To validate the design concept, a second-order hybrid SD-EMCSIW and CSRR BPF was designed, simulated, fabricated, and measured as a specific example. The prototype operates at a center frequency f₀ of 8.3 GHz with a 3 dB fractional bandwidth of 8.1%. Two transmission zeros are located near the right passband. The upper-stopband rejection reaches up to 15 dB at 2.85 times the center frequency f₀. Both the simulated and measured results show satisfactory agreement. Meanwhile, the overall size of the proposed hybrid SD-EMCSIW and CSRR BPF is 13.5 mm × 13.0 mm (0.37λ₀ × 0.36λ₀), featuring a compact physical dimension in the filter design. Full article

Innovation in plastic waste recycling technologies is essential for tackling the environmental challenges of plastic pollution. Traditional plastic waste management strategies, such as landfill disposal and mechanical recycling, are increasingly recognized as insufficient for addressing the problem’s complexity and scale. This review highlights advanced methods that transform plastic waste into valuable resources, aligning with circular economy principles. I focus on cutting-edge technologies such as chemical recycling that convert mixed and contaminated plastics back into monomers for new production. Biological approaches utilizing enzymes and microorganisms are studied for their potential to biodegrade resistant plastics like PET. Additionally, mechanical innovations like advanced sorting techniques leveraging AI and compatibilization strategies that enhance the quality of recycled materials are discussed. By analyzing recent developments and practical applications, effective and economically viable solutions are identified. These findings emphasize that ongoing technological advancements, supported by robust policies and stakeholder collaboration, are crucial for reducing plastic waste and advancing toward a sustainable circular economy. Full article

In order to study the effect of a warm-mix agent on the compaction characteristics of an anti-rutting asphalt mixture, this study compared the compaction temperature of an anti-rutting asphalt mixture with different warm-mix-agent contents from two aspects: asphalt viscosity and asphalt mixture voids. Based on the rheological properties of asphalt, the optimal content of the anti-rutting agent was first determined as 6% by the weight of asphalt. Four warm-mix-agent contents of 0% (control group), 1%, 2%, and 3% were designed. The viscosity–temperature curve of the warm-mix anti-rutting modified asphalt was obtained by the Brookfield viscosity tests. After that, AC-20 standard Marshall specimens were prepared to conduct a series of consecutive temperature compaction tests. The voids were calculated based on the bulk density of the specimen measured by the saturated surface-dry method. Industrial Computerized Tomography (CT) was employed to further quantify the internal voids. Two voids–compaction temperature curves were constructed based on the saturated surface-dry and CT results, respectively. The comparative results show that significant differences exist between the compaction temperatures obtained from the three curves. The viscosity–temperature curve shows that when the warm-mix agent is increased from 0% to 3%, the compaction temperature only declines about 7.9%. However, the voids–compaction temperature curves from saturated surface-dry and CT, respectively, indicate a temperature decrease of 22.7% and 19.2%. This is because a warm-mix agent will interact with asphalt, resulting in a decrease in asphalt intermolecular adsorption, whereas an anti-rutting agent mixed with asphalt will increase the degree of cross-linking and aggregation between asphalt molecules. Both additions have a certain impact on the viscosity of the asphalt binder; thus the traditional method of using the asphalt viscosity–temperature curve to determine the compaction temperature of warm-mix anti-rutting asphalt mixture has become ineffective. It is suggested to use the equal voids method to determine the compaction temperature of warm-mix anti-rutting asphalt mixtures. Full article

Extensive research about non-exhaust fine particles from tires and brakes in vehicles has been reported, focusing on the significant effects on air pollution and human harm. Significant investigations are still needed in determining the cause of influence on the environment and human health. The regulations on emissions have been discussed in earnest, starting with the introduction of brake wear particle emission standards in Euro 7. Various indoor and outdoor experiments have been conducted, such as analysis of the amount of wear on tires and brakes, and analysis of the physical and chemical properties of fine particles, and the effect of non-exhaust fine wear particles on the atmosphere and human health, as fundamental data for the introduction of emission standards and the development of low-wear tires and brakes to meet regulations. Recently, international standardized indoor experimental methods for brakes have been announced, and indoor and outdoor experimental methods for tires have been continuously studied to develop international standardized methods. In particular, tire and road wear particles, including brake wear particles, are usually mixed with each other in the non-exhaust particles from a vehicle driving on real roads, and in-depth research is being performed on their accurate classification and characteristic analysis. In this study, the characteristics of the volatile organic compounds and marker substances for tire and tire and road wear particles were analyzed. A system was installed on the vehicle to collect non-exhaust wear fine particles from the vehicle running on two different roads, urban and suburban, of the Seoul area, and the proving ground road. The specific findings are as follows: (1) From the chemical analysis of the volatile organic compounds, high n-hexane and n-dodecane were measured in the tire–road-wear particles. (2) The volatile organic compound species in the PM2.5 (aerodynamic diameter ≤ 2.5 µm) increased as the vehicle velocity increased. (3) For the PM10 (aerodynamic diameter ≤ 10 µm), high volatile organic compound species were recorded at 40 km/h of the vehicle velocity. (4) This study also revealed that higher vinylcyclohexene and dipentene were measured in the particle size below 10 μm than those in PM2.5. Full article

Glass Fiber-Reinforced Composite (GFRP) has found widespread use in engineering structures due to its lightweight construction, high strength, and design flexibility. However, pure GFRP beams exhibit weaknesses in terms of stiffness, stability, and local compressive strength, which compromise their bending properties. In addressing these limitations, this study introduces innovative square GFRP beams infused with gypsum-based composites (GBIGCs). Comprehensive experiments and theoretical analyses have been conducted to explore their manufacturing process and bending characteristics. Initially, four types of GBIGC—namely, hollow GFRP beams, pure gypsum, steel-reinforced gypsum, and fiber-mixed gypsum-infused beams—were designed and fabricated for comparative analysis. Material tests were conducted to assess the coagulation characteristics of gypsum and its mechanical performance influenced by polyvinyl acetate fibers (PVAs). Subsequently, eight GFRP square beams (length: 1.5 m, section size: 150 mm × 150 mm) infused with different gypsum-based composites underwent four-point bending tests to determine their ultimate bending capacity and deflection patterns. The findings revealed that a 0.12% dosage of protein retarder effectively extends the coagulation time of gypsum, making it suitable for specimen preparation, with initial and final setting times of 113 min and 135 min, respectively. The ultimate bending load of PVA-mixed gypsum-infused GFRP beams is 203.84% higher than that of hollow beams, followed by pure gypsum and steel-reinforced gypsum, with increased values of 136.97% and 186.91%, respectively. The ultimate load values from the theoretical and experimental results showed good agreement, with an error within 7.68%. These three types of GBIGCs with significantly enhanced flexural performance can be filled with different materials to meet specific load-bearing requirements for various scenarios. Their improved flexural strength and lightweight characteristics make GBIGCs well suited for applications such as repairing roof beams, light prefabricated frames, coastal and offshore buildings. Full article

Interstitial lung disease (ILD) is one of the common and potentially lethal manifestations of systemic autoimmune rheumatic diseases (SARDs). ILD’s prevalence, clinical patterns, imaging, and natural history are variable. Each of the representative diseases—systemic sclerosis (SSc), idiopathic inflammatory myopathies (IIMs), rheumatoid arthritis (RA), Sjӧgren’s syndrome (SjS), mixed connective tissue disease (MCTD), systemic lupus erythematosus (SLE)—have distinct clinical, paraclinical and evolutionary features. Risk factors with predictive value for ILD have been identified. This review summarizes, from the clinician’s perspective, recent data from the literature regarding the specificity of ILD for each of the autoimmune rheumatic diseases, with an emphasis on the role of the multidisciplinary team in early diagnosis, case management, as well as the particularities of the clinical approach to the progressive phenotype of ILD in SARDs. Full article