Search Results (620)

Indoor air pollution is a major cause of noncommunicable diseases, and increasing people’s knowledge about the related risks is a key action for prevention. Many studies describe questionnaires for evaluating knowledge on indoor air quality that often involve selected population groups and take time to fill out. This study describes the validation of a questionnaire built “ad hoc” that aims to be easy to fill out, reliable, and valid. The validation process integrated two psychometric approaches: the Classical Test Theory (CTT), which uses the Kuder–Richardson 20 (KR-20) formula to measure the internal consistency and reliability of the questionnaire as a whole, and the Item Response Theory (IRT), which evaluates each statement (item)’s validity. The questionnaire, distributed using social media to a self-selected sample of people, reached a sample of 621 subjects. In terms of internal consistency, the questionnaire was found to be satisfactory, with a KR-20 value of 0.74 (CI 0.71–0.77). The IRT analysis showed that the statements included in the questionnaire can distinguish between high-performing and low-performing interviewees, since 100% of the items reached a value of the “discrimination parameter a_j” that was within or above the recommended range. In terms of difficulty, many statements (53.3%) showed a low level of difficulty, obtaining a low “difficulty parameter b_j” value, while another 20% of the items showed a high level of difficulty. Regarding the pseudo-guessing parameter, known as the c-parameter, the probability of answering correctly for a low-performing interviewee was observed in three items (1, 6, and 9), and the same statements fell outside the range for all three parameters evaluated in the IRT. The application of the IRT highlights the criticality of some questions that would not have emerged using the CTT approach alone. Although the questionnaire is acceptable overall, it will be appropriate to evaluate whether to revise or exclude the critical questions in order to improve the instrument’s performance. Full article

In order to optimize the preparation process of microlens arrays, improve preparation efficiency, and reduce preparation costs, 248 nm KrF excimer laser direct writing is combined with a motion mask to prepare microlens arrays on PMMA substrates. Firstly, a specific exposure mask based on the contour characteristics of the microlens unit was designed, and the preparation principle was analyzed. Using COMSOL Multiphysics 6.3 simulation software, a microlens preparation model was built to intuitively describe the process of preparing microlenses by the motion mask method. Secondly, a preparation system was built, and the laser processing technology was optimized. Finally, microlens arrays were prepared based on the optimized process, and an optical microscope and white-light interferometer were used to observe their morphology. The experimental results show that this method can effectively prepare cylindrical and circular microlens arrays. The width of the cylindrical microlens array unit exceeded 90 μm, the height was 7.08 μm, and the roughness was 0.09 μm. The diameter of the circular microlens array unit was φ100 μm, the height was 4 μm, and the curvature radius was 230 μm. The geometric dimensions of the mask can be adjusted to obtain microlens units of the desired size, achieving personalized preparation of microlens arrays. The excimer laser motion mask method can prepare various types of microlens arrays, and the array units have a high consistency and high surface quality, which helps to improve the efficiency, flexibility, stability, and specificity of microlens array preparation. Full article

In karst regions (KRs), unique surface morphology and irrational human exploitation have led to increasingly prominent issues such as land fragmentation and rocky desertification. Understanding the spatiotemporal evolution of cultivated land (CL) in these areas is of great significance for supporting regional socioeconomic development, food security, and ecological sustainability. This study focuses on Guilin, combining GIS spatial analysis with methods including kernel density analysis, dynamic degree, spatial transfer matrix, and a Geodetector to examine the spatiotemporal distribution characteristics, evolution trends, and driving factors of land use based on five-phase of land use data from 2000 to 2020. The results show that: (1) over the past two decades, land use in Guilin has been dominated by CL and forest land, with CL exhibiting a spatial pattern of more in the east and south, and less in the west and north; (2) the CL transfer-out rate exceeded the transfer-in rate, mainly shifting to construction land and forest land; (3) the overall density of CL showed a declining trend, with a relatively stable spatial pattern; and (4) driving factor analysis indicates that the spatiotemporal changes in CL are jointly influenced by multiple factors, with natural factors exerting a stronger influence than socio-economic factors. Among them, the interaction between elevation and temperature had the greatest impact and served as the dominant factor. Although GDP and population were not dominant individually, their explanatory power and sensitivity increased significantly when interacting with other factors, making them key sensitive factors. The results can provide a scientific reference for the protection and rational utilization of CL resources in KR. Full article

Wireworms are often referred as a hardly manageable group of pests due to their unstable lifestyle and uneven distribution in soils. The current strategy of wireworm control involves the heavy use of chemical pesticides. To find an effective and eco-friendly biological control agent against wireworms, evaluation of bacterial properties and insecticidal effects of six Bacillus thuringiensis (Bt) strains against Agriotes lineatus was performed under laboratory conditions. The presence of cry11, cyt2 and krsA gene was detected in Bt strain BHC 2.4, while the same strain had the ability to produce siderophores, protease, amylase and cellulase. Single inoculums of Bt strains (BHC 2.4; BHC 4.5; BHC 4.7; 1.5; 4.3; 6.1) showed mortality against Agriotes lineatus larvae in the range of 6.67–72.22%. However, the compatible Bt dual cultures showed significantly higher efficiency in comparison with the single inoculums, with the highest efficiency of 79.63% recorded for Bt strain BHC 2.4 + Bt strain 1.5. The efficiency of applied Bt strains might be associated with the presence of genes coding for antibiotics and toxins. Therefore, the use of selected Bt strains applied in a form of compatible mixes could offer a sustainable solution for wireworm management in wheat. Full article

Angle crack defects significantly affect compressor blade radial deformation characteristics, posing critical challenges for reliability assessment under operational uncertainties. This study proposes a novel osprey optimization algorithm (OOA)-optimized Kriging and radial basis function (RBF) method (OOA-KR) for the efficient reliability evaluation of blade radial clearance with angle crack defects. The approach integrates Kriging’s uncertainty quantification capabilities with RBF neural networks’ nonlinear mapping strengths through an adaptive weighting scheme optimized by OOA. Multiple uncertainty sources including crack geometry, operational temperature, and loading conditions are systematically considered. A comprehensive finite element model incorporating crack size variations and multi-physics coupling effects generates training data for surrogate model construction. Comparative studies demonstrate superior prediction accuracy with RMSE = 0.568 and R² = 0.8842, significantly outperforming conventional methods while maintaining computational efficiency. Reliability assessment achieves 97.6% precision through Monte Carlo simulation. Sensitivity analysis reveals rotational speed as the most influential factor (S = 0.42), followed by temperature and loading parameters. The proposed OOA-KR method provides an effective tool for blade design optimization and reliability-based maintenance strategies. Full article

Lithium fluoride (LiF) crystals are widely employed both as optical windows transparent in the ultraviolet spectral region and as efficient personal dosimeters, with their application scope recently expanding into lithium-ion technologies. Moreover, as an alkali halide crystal (AHC), LiF serves as a model system for studying and simulating radiation effects in solids. This work identifies radiation-induced defects formed in lithium fluoride upon irradiation with swift heavy ion beams (N, O, Kr, U) and intense pulsed electron beams, investigates their thermal stability, and performs computer modeling of annealing processes. The theoretical analysis of existing experimental kinetics for $F$-centers induced by electron and heavy ion irradiation reveals considerable differences in the activation energies for interstitial migration. A strong correlation between the activation energy $E_a$ and the pre-exponential factor $X$($E_a$) is observed; notably, $X$($E_a$) is no longer constant but closely matches the potential function Ea. Indeed, with increasing irradiation dose, both the migration energy $E_a$ and pre-exponential factor $X$ decrease simultaneously, leading to an effective increase in the defect diffusion rate. Full article

The huge growth in the utilisation of six-axis robots in various technological applications in production calls for a detailed focus on the process of preparing Numerical Control (NC) programmes for effective robot control. Considerable attention is currently being paid to optimisation by increasing stiffness, but there is also a need to focus on reducing energy consumption in robot control. Focusing on reducing energy consumption is highly justified given the widespread adoption of robotic systems across diverse manufacturing technologies and the significant potential for application. This is particularly relevant today, when minimising production costs is a critical industrial objective. A redundant degree of freedom—which is the possibility to rotate around the end-effector axis and thus influence the adjustment of the rotation of the individual robot joints—can be used for this purpose. Therefore, this paper exploits this redundant degree of freedom to set up a proper robot configuration that reduces energy consumption. The user-friendly solution, including the algorithm design and processing through a function, could be effectively implemented within an industry-standard post-processor solution for generating NC programmes for robots. This solution is unique as it is used for the optimisation of the working section of the toolpaths, where continuous control of the end-effector movement during manufacturing operations occurs. The solution was verified on a KUKA KR60 HA robot; however, it is applicable to any industrial six-axis robot. Substantial energy savings were obtained in multi-axis toolpath operations, with a 7.5% reduction in total energy consumption when using the optimised NC programme. Full article

In this study, we present the development of a high-average-power, exceptionally stable extreme-ultraviolet (EUV) laser source based on a high-order harmonic generation (HHG) technique. The spectrum of an ytterbium-doped laser is broadened through self-phase modulation (SPM) in a gas-filled hollow fiber and compressed down to 25.3 fs for efficient harmonic generation. The high harmonics are generated in a krypton (Kr) gas cell, delivering a total power of 241 μW within the 30–60 nm spectral range, corresponding to a single harmonic output of 166 μW at a central wavelength of 46.8 nm. Notably, the system demonstrates good power stability with a root-mean-square (RMS) deviation of only 1.95% over 12 h of continuous operation. This advanced light source holds great potential for applications in nano- and quantum-material development and in semiconductor wafer defect detection. Future work aims to further enhance the output power in the 30–60 nm band to the milliwatt level, which would significantly bolster scientific research and technological development in related fields. Full article

Background: As a globally significant aquaculture species, elucidating the molecular mechanisms underlying the regulation of the Pacific White Shrimp (Litopenaeus vannamei) growth holds substantial scientific and industrial value. This study systematically investigates the role of the LvChia2 gene in governing growth and development through a cross-tissue metabolic network approach. Methods: RNA knockdown (RNAi)-mediated knockdown of LvChia2 significantly impaired growth performance and triggered a tissue-specific metabolic compensation mechanism. Results: This mechanism was characterized by reduced crude lipid content in muscle and adaptive modulation of lipase (LPS) activities in hepatopancreatic and intestinal tissues, suggesting inter-tissue metabolic coordination. Transcriptomic profiling identified 610 differentially expressed genes (DEGs), forming a three-dimensional regulatory network encompassing “energy metabolism, molt regulation, and nutrient utilization.” Key mechanistic insights revealed the following: (1) Enhanced mitochondrial energy transduction through the upregulation of ATP synthase subunits and NADH dehydrogenase (ND-SGDH). (2) The disruption of ecdysteroid signaling pathways via suppression of Krueppel homolog 1 (Kr-h1). (3) The coordinated regulation of nitrogen metabolism through the downregulation of glutamine synthetase and secretory phospholipase A2. These molecular adaptations, coupled with tissue-specific oxidative stress responses, reflect an integrated physiological strategy for environmental adaptation. Conclusions: Notably, this study provides the first evidence in crustaceans of chitinase-mediated growth regulation through cross-tissue metabolic interactions and identifies six core functional genes (ATP5L, ATP5G, ND-SGDH, Kr-h1, GS, sPLA2) as potential targets for molecular breeding. A novel “gut-hepatopancreas axis” energy compensation mechanism is proposed, offering insights into resource allocation during metabolic stress. These findings advance our understanding of crustacean growth regulation and establish a theoretical foundation for precision aquaculture strategies, including genome editing and multi-trait genomic selection. Full article

Optical biosensors play a crucial role in the field of biological detection by converting biological signals into optical signals for detection. Among them, Surface Plasmon Resonance (SPR) optical biosensors have become a research hotspot in this field due to their significant advantage of high sensitivity. Weyl Semimetals (WSMs), as a type of three-dimensional topological material with unique electronic structures and other properties, exhibit potential applications in the field of SPR sensing. Against this background, we designed a terahertz (THz) high-sensitivity SPR phase biosensor with a KR structure based on WSMs. When applied in gas sensing scenarios, the phase detection sensitivity of this sensor can reach 22,402$°$/RIU, showing a significant improvement compared to traditional SPR biosensors. Moreover, we found that the Weyl node separation distance and twist angle of WSMs have obvious effects on sensitivity regulation. Additionally, we optimized the sensitivity and structural parameters of this structure using a neural network-based deep learning algorithm. We expect that this proposed scheme can provide a feasible reference for the field of biological sensing. Full article

The invertebrate neuropeptide F (NPF) signaling plays versatile roles in diverse biological activities and processes. Still, whether and how it mediates feeding and digestion in Pomacea canaliculate remain gaps in our knowledge. Herein, we first identified and characterized PcNPFR via bioinformatics analysis in P. canaliculate, which is a polyphagous herbivore with a voracious appetite that causes devastating damages to ecosystem functioning and services in colonized ranges. Double stranded RNA (dsRNA)-based RNA interference (RNAi) and exogenous rescue were utilized to decipher and substantiate underlying mechanisms whereby NPFR executed its modulatory functions. Multiple sequence alignment and phylogeny indicated that PcNPFR harbored typical seven transmembrane domains (7 TMD) and belonged to rhodopsin-like GPCRs, with amino acid sequence sharing 27.61–63.75% homology to orthologues. Spatio-temporal expression profiles revealed the lowest abundance of PcNPFR occurred in pleopod tissues and the egg stage, while it peaked in male snails and testes. Quantitative real-time PCR (qRT-PCR) analysis showed that 4 µg dsNPFR and 10⁻⁶ M trNPF (NPFR agonist) were optimal doses to exert silencing and rescue effects, accordingly with sampling time at 3 days post treatments. Moreover, the dsNPFR injection (4 µg) at 1/3/5/7 day/s delivered silencing efficiency of 32.20–74.01%. After 3 days upon dsNPFR knockdown (4 µg), mRNA levels of ILP7/InR/Akt/PI3Kc/PI3K_R were significantly downregulated compared to dsGFP controls, except FOXO substantially upregulated at both transcript and translation levels. In addition, the activities of alpha-amylase, protease and lipase were significantly suppressed, accompanied by decreased leaf area consumption, attenuated feeding behavior and diminished feeding rate. Moreover, expression trends were opposite and proxies were partially or fully restored to baseline levels post exogenous compensation of trNPF, suggesting phenotypes specifically attributable to PcNPFR RNAi but not off-target effects. PcNPFR is implicated in both feeding and digestion by modulating the ISP pathway and digestive enzyme activities. It may serve as a promising molecular target for RNAi-based antifeedants to manage P. canaliculate invasion. Full article

Global climate change mitigation has prompted the construction sector to pursue decarbonization strategies, with timber structures offering significant carbon reduction potential. Wood serves as a sustainable material that sequesters carbon during growth while reducing emissions across the entire construction supply chain. Robotic construction of timber structures is increasingly promoted as a low-carbon, intelligent alternative for small- and medium-scale projects, yet the energy consumption and environmental impacts of robotic automated assembly using self-tapping screws remain understudied. This study presents a construction-phase life-cycle assessment (LCA) of an innovative vertically mobile robotic construction system for automated timber structure. The system integrates a KUKA KR 6 R900 (KUKA Robotics Corporation, Augsburg, Germany) six-axis robot with an electrically actuated lifting platform and specialized end-effector, enabling fully autonomous assembly of a Layered Interlaced Timber Arch-Shell (LITAS) structure using Hinoki cypress timber and self-tapping screws. This research provides the first comprehensive LCA dataset for robotic screw-fastened timber construction and establishes a replicable framework for sustainable automated building practices, with methodology scalability enabling application to diverse timber construction scenarios and advancing intelligent and decarbonized transformation in the construction industry. Full article

In this study, highly ordered titanium dioxide nanotubes (TiO₂-NTs) have been synthesized using the electrochemical anodization procedure. Subsequently, the TiO₂-NTs were successfully decorated with PbS nanoparticles (NPs) using the pulsed KrF-laser deposition (PLD) technique under vacuum and under different Helium background pressures (P_He) ranging from 50 to 400 mTorr. The prepared samples (PbS-NPs/TiO₂-NTs) were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and UV–Vis and photoluminescence spectroscopies. XRD analyses confirmed that all TiO₂-NTs crystallized in the anatase phase, while the PbS-NPs crystallized in the cfc lattice. The average crystallite size of the (200) crystallites was found to increase from 21 to 33 nm when the pressure of helium (PHe) was raised from vacuum to 200 mTorr and then dropped back to ~22 nm at P_He = 400 mTorr. Interestingly, the photoluminescence intensity of the PbS-NPs/TiO₂-NTs samples was found to start diminishing for P_He ≥ 200 mTorr, indicating a lesser recombination rate of the photogenerated carriers, which also corresponded to a better photocatalytic degradation of the Amido Black (AB) dye. Indeed, the PbS-NPs/TiO₂-NTs samples processed at P_He = 200 and 300 mTorr were found to exhibit the highest photocatalytic degradation efficiency towards AB with a kinetic constant 130% higher than that of bare TiO₂-NTs. The PbS-NPs/TiO₂-NTs photocatalyst samples processed under P_He = 200 or 300 mTorr were shown to remove 98% of AB within 180 min under UV light illumination. Full article

Soil erosion in granite-derived weathering mantles poses serious threats to slope stability and ecological sustainability in subtropical regions. While polyacrylamide (PAM) is widely used to improve soil structure, its concentration-dependent effects on multiple soil functions remain unclear. This study developed a multifunctional Soil Function Index (SFI) framework integrating erosion resistance (SFI₁), water regulation (SFI₂), and ecological function (SFI₃) to evaluate the effects of PAM application (0‰, 1‰, 3‰, 5‰, 7‰) on gully-prone sandy material. Herein, SFI₁ was quantified through shear strength (τ) and soil erodibility (K_r); SFI₂ was assessed using soil hydraulic parameters (saturated hydraulic conductivity and water retention curves) and SFI₃ was derived from the grass root system analysis. The results showed that SFI₁ and SFI₂ increased nonlinearly with PAM concentration, reaching maximum values of 0.983 and 0.980 at 7‰, with K_r reduced by 77.3% and non-capillary porosity (NAP) increased by 8.1%. In contrast, SFI₃ peaked at 0.858 under 3‰ and declined sharply to 0.000 at 7‰, due to micropore over-compaction, reduced aeration, and limited plant-available water. The total SFI exhibited a unimodal trend, with a maximum of 0.755 at 3‰, beyond which ecological suppression offset physical improvements. These findings demonstrate that PAM modifies soil multifunctionality through pore-scale restructuring, inducing function-specific thresholds and trade-offs. A PAM concentration of 3‰ is identified as optimal, achieving a balance between erosion control, hydrological performance, and ecological viability in the management of subtropical granite-derived sandy slopes. Full article

In addressing the limited absolute positioning accuracy of industrial robots, which stems from the discrepancy between the nominal kinematic model and the physical entity, this paper proposes a novel paradigm for online compensation based on data-driven error prediction. The present study utilized a KUKA KR4 R600 robot as the experimental platform to construct a high-fidelity digital twin system capable of real-time synchronization. Within this framework, a new machine learning model, termed the Global Configuration-Error Forest (GCE-Forest), was developed and validated. The fundamental principle of GCE-Forest, based on the Random Forest algorithm, is its offline learning of the complex, highly non-linear mapping from the robot’s six-dimensional joint space configuration to its three-dimensional end-effector Cartesian error space. This facilitates online, feedforward, and predictive compensation for the nominal trajectory during robot operation. Through rigorous comparative experiments, the superiority of the proposed GCE-Forest was established. The final outcomes of dynamic trajectory tracking validation demonstrate that the system, by accurately predicting a mean nominal error of 0.1977 mm, successfully reduced the average spatial positioning error of the end-effector to 0.0845 mm, achieving an accuracy improvement of 57.25%. This research provides comprehensive validation of the method’s robust performance, offering a low-cost, non-invasive, and highly effective solution for significantly enhancing robotic accuracy. Full article