Search Results (794)

Electrochemical machining is widely recognized as a high-efficiency, low-cost and high-precision non-traditional machining technology for the manufacturing of turbine blade components. Nevertheless, in the practical electrochemical machining of turbine blades, the uneven spatial distribution of electric field intensity within the inter-electrode machining gap inevitably causes inconsistent anodic dissolution, which significantly deteriorates the final surface quality of machined blades. A set of comparative machining experiments were conducted on Inconel 625 superalloy. The experimental results fully verified that pulsed current machining could effectively improve the surface integrity and surface quality, and the optimal matching electrical parameters were successfully determined through systematic data analysis. The essential improvement mechanism lied in the effective suppression of stray current-induced scattered dissolution under pulsed power supply, which was highly consistent with the numerical simulation conclusions. Full article

Atmospheric aerosols from natural and anthropogenic sources are a major component of air pollution and substantially affect air quality, human health, and atmospheric chemistry. Reliable and continuous aerosol optical depth (τ_aer) measurements from ground-based instruments are therefore essential for characterizing aerosol loading and its spatiotemporal variability. This study presents a framework for retrieving τ_aer in the UV (315–375 nm) and visible (400–530 nm) spectral ranges using the Pandora spectrometer. In the ultraviolet (UV) range, reliable τ_aer retrieval from standard direct-Sun measurements is hindered by out-of-band stray light from visible wavelengths. To address this limitation, this study utilizes measurements acquired with a U340 filter, which suppresses this contamination in UV spectra and enables reliable τ_aer retrievals in the UV region. Through the proposed spectral fitting framework, trace gas absorption and aerosol extinction components are successfully separated from the measured total optical depth. Concurrently, τ_aer values at visible wavelengths are retrieved from standard Diffuser measurements. The retrieved UV and visible τ_aer values show good agreement with collocated AErosol RObotic NETwork (AERONET) data, with R² = 0.88–0.99, RMSE = 0.016–0.039, |MBE| = 0.002–0.023, slopes of 0.93–1.01, and |intercepts| < 0.01. Together with the trace gas products simultaneously retrieved by Pandora, these τ_aer datasets can serve as a valuable resource for air pollution analysis. Full article

Microfluidic Hall-effect biosensors detect superparamagnetic bead labels as they flow past a thin-film Hall element in a microchannel. Designing one couples bead magnetization, stray-field distribution, Hall transport, and channel flow across 14 parameters that finite-element solvers explore only at minutes to hours per configuration. We present a coupled analytical–numerical framework for this signal chain: Clausius–Mossotti bead magnetization with a volume fraction correction, a point-dipole stray field, a volume-averaged Hall voltage, Poiseuille transport, and a Johnson–Nyquist and Hooge $1/f$ noise model, evaluated across 12 sensor presets compiled from the literature, spanning graphene, III–V semiconductors, Si CMOS, bismuth, and topological insulators; any other platform can be defined from user-supplied transport parameters. Benchmarked against a companion COMSOL Multiphysics 6.0 study, the framework reproduces the Hall voltage to within 4.8% at a favorable bead-to-sensor area ratio and deviates by 22% and 15% at off-optimum geometries, consistent with the point-dipole near-field limit at $h/r_b=1$. Three design rules follow: a signal-to-noise ridge at sensor widths comparable to the bead diameter ($w^{*}\approx d_b$; area ratios 0.4–1.0 at constant voltage, 0.5–2.6 at constant current), matching reported single-bead geometries; a material choice that must be made under an explicit electrical drive constraint; and a sampling-limited flow-velocity window. Predicted signals agree at the order-of-magnitude level with published InAs and Si CMOS experiments. We release the model as a freely accessible, no-install browser implementation with a built-in 2D axisymmetric magnetostatic finite-element (FEM) solver that maps where the dipole approximation degrades. Full article

Shield tunnels are the primary structural form of subway tunnels. Under the influence of sulfate ions and stray currents, the internal bars in shield tunnels will corrode rapidly, affecting the safe operation of the subway. In this paper, a numerical calculation model was developed to simulate rebar corrosion in shield tunnels under coupled electric and chemical field effects, the accuracy of the numerical calculation model was verified using a model test. Based on this model, the migration patterns of sulfate ions within the tunnel under stray current conditions are investigated, as well as the corrosion mechanisms of tunnel rebars. Results show that under the coupled effects of stray currents and sulfate ions, the corrosion area in a segment rebar gradually spreads from the arch waist area of a tunnel. Compared to bilateral leakage, both the migration rate of sulfate ions and the corrosion rate of rebar were higher than those in the unilateral leakage condition. Changes in the input voltage at the top of the ballast did not alter the shape of the distribution curves for the voltage and corrosion current density of segmental rebar. When the input voltage increased from 1 V to 5 V, the voltage at the mid-section of the rebar increased by 5.2 times under a bilateral leakage condition, and the voltage at the mid-section of the rebar increased by 8.2 times under a unilateral leakage condition. Compared to the bilateral leakage case, the amplitude of fluctuations in the curve was significantly reduced under unilateral leakage, but the corrosion current density increased proportionally with increasing leakage voltage in both cases. The research conclusions provide a theoretical basis for the safety assessment and disease treatment of shield tunnel structures. Full article

With the large-scale deployment of high-voltage direct current (HVDC) transmission projects, monopolar ground return operation has increasingly intensified stray current interference risks to adjacent buried metallic pipelines. This study investigates a high-pressure natural gas pipeline project in Guangdong Province by integrating field monitoring, soil resistivity measurements, polarization characterization, and numerical simulations to elucidate the potential distribution characteristics and corrosion evolution mechanisms under stray current influence. The results indicate that under an extreme operating condition of 1980 A, the pipe-to-soil potential shift ranges from −71 V to 69.9 V, significantly exceeding the safety threshold, while the maximum corrosion rate reaches 0.34 mm/y. Based on this, a combined protection system consisting of zinc ribbon drainage, deep-well drainage, and forced current drainage is further proposed. The selected mitigation scheme reduces the maximum corrosion rate to 0.0017 mm/y, demonstrating excellent mitigation performance. The results can provide theoretical and engineering references for the design, protection, and operation of long-distance pipelines in HVDC interference environments. Full article

Canine dirofilariosis caused by Dirofilaria immitis and Dirofilaria repens is a vector-borne zoonotic infection of considerable veterinary and public health importance. Despite reports of the circulation of Dirofilaria spp. in neighboring countries, data on the molecular prevalence, species composition, and genetic diversity of these parasites in dogs from Kazakhstan remain limited. In the present study, owned, shelter, and stray dogs, which serve as the principal reservoirs of infection, were examined for the presence of microfilariae in blood, and the circulation of Dirofilaria spp. was molecularly confirmed. The study was conducted between September 2024 and January 2026 and included 751 canine blood samples collected from 10 regions of Kazakhstan. Initial screening was performed using the modified Knott test. Molecular identification was carried out through amplification of the mitochondrial cox1 gene, followed by DNA sequencing and comparative analysis with reference sequences available in GenBank. Phylogenetic analysis was performed to assess the genetic relationships of the detected isolates. The overall molecular prevalence of Dirofilaria spp. was 3.6% (27/751). The highest infection rate was recorded in the Aktobe region (22.3%), while positive cases were also detected in the Akmola (2.7%), Kostanay (1.7%), and West Kazakhstan (1.8%) regions. Species identification revealed the predominance of D. repens, whereas D. immitis was detected only in Aktobe region. Phylogenetic analysis confirmed the species identity of all obtained sequences and demonstrated a high degree of genetic similarity with Dirofilaria isolates previously reported from Europe and Asia. These findings confirm the circulation of Dirofilaria spp. among dogs in several regions of Kazakhstan and indicate the ongoing expansion of canine dirofilariosis in Central Asia. This study provides the first molecular genetic data on Dirofilaria spp. in dogs from Kazakhstan and highlights the need for continued epidemiological surveillance and assessment of potential risks to animal and human health. Full article

The 1st International Online Conference on Environments addresses issues of environmental understanding, management, and restoration. Sessions ranged from general frameworks to a broad area of specific investigations: heavy metal removal using inactive yeast, gadolinium’s aquatic toxicity, adsorptive removal of pollutants, energy recovery from waste and wastewater treatment, recycled carbon fibers, climate-resilient urban development, renewable biofuel production, green hydrogen, anthropogenic and volcanic CO₂ emissions, quantifying aging dignity in urban ecosystems and stray dogs as pollution health sentinels. Keynotes covered digital plant phenotyping for restoration, microplastic dynamics, agricultural residue management, carbon credits, air quality, atmospheric pollution, transitional waters, green chemistry, ecotoxicity, micropollutants, and coastal darkening effects on plankton, among others. Applied solutions included phytoremediation of eutrophication in urban streams, circular approaches in aquaculture, biochar for wastewater treatment, AI-assisted mangrove monitoring, and true-cost accounting for food systems. The conference demonstrated that effective environmental policy requires the integration of laboratory findings, field restoration, and shared resource responsibility across terrestrial and marine ecosystems. Full article

For gravitational wave observation, an optical design of the telescope has been implemented to perfectly match the laser interferometry system, and stray light analysis is used to quantify the impact of mirror roughness noise on interferometric measurement sensitivity. An off-axis six-mirror afocal optical design, comprising a parabolic primary, hyperbolic secondary and plane-parabolic collimation group, delivers an optical system with a 400 mm entrance pupil, 100× expansion ratio, and λ/30@1064 nm Root Mean Square (RMS) wavefront quality. To obtain a feasible exit pupil position which can easily integrate the laser interferometer, the theoretical mathematical relationships among the exit pupil position, primary–secondary mirror spacing, and radius of curvature of the secondary mirror and the sixth mirror are derived. Accordingly, the effective exit pupil position is extended to 174 mm to match the laser interferometer. The sixth mirror is the primary source of backscattered light. With the RMS roughness of the primary, secondary, and three folding mirrors set to 6.4 Å, 1.6 Å, and 3.7 Å, respectively, the Point Source Transmittance (PST) value can be kept below 3.6 × 10⁻¹⁰ when the RMS roughness of the sixth mirror is less than 1.1 Å. Tolerance analysis is carried out to obtain the feasible engineering distribution of optical parameters, and the statistical results show that the system RMS wavefront error is smaller than 0.01λ@1064 nm. Full article

Background: The aim of the present study was to develop and optimize an experimental ELISA test system for the detection of IgG antibodies to Toxocara canis and subsequently apply it for the assessment of human and canine exposure in Uralsk, Kazakhstan, within a One Health framework. Methods: A native somatic antigen of T. canis was fractionated by gel filtration, and the working fraction was selected by SDS-PAGE and pilot ELISA. The optimized test system was used for the analysis of sera of 1000 adult volunteers. Antibody avidity was determined in IgG-positive human specimens, and human seropositivity was evaluated for associations with demographic and questionnaire-derived variables. Serum samples from 100 stray dogs were tested by ELISA and fecal samples by copromicroscopy. Agreement with the commercial DRG ELISA was tested with 50 positive and 50 negative human serum samples. Results: The antigen fraction of 18–22 kDa showed the best separation between positive and negative sera. IgG antibodies against T. canis were detected in 116/1000 volunteers (11.6%). Seropositivity was 17.0% in the 2025 sample and 6.2% in the 2026 sample (odds ratio 3.10; 95% confidence interval 2.01–4.77; p < 0.001). No significant associations were found with sex, age, residence, or questionnaire-derived variables. Among seropositive volunteers, 28.4% had low-avidity, 26.7% intermediate-avidity, 29.3% intermediate/high-avidity and 15.5% high-avidity IgG. Overall, 78/100 of the stray dogs were copropositive, and 93/100 were seropositive. All copropositive dogs were seropositive, and 15 additional seropositive dogs were copronegative. Agreement with the DRG ELISA was 97.0% (Cohen’s κ = 0.94). Conclusions: The experimental ELISA allowed the assessment of T. canis exposure of humans and dogs. Seropositivity in humans in Uralsk showed exposure. High seropositivity in dogs and frequent egg shedding showed a substantial canine reservoir and a potential for environmental contamination. These results support integrated surveillance and control within a One Health context. Full article

Field voltage testing after the maintenance of large converter transformers requires high-voltage response verification while preserving the restored equipment boundary. However, conventional direct voltage application on the grid side usually requires the disconnection of high-voltage leads and auxiliary devices, which may alter the original electrical boundary and increase field disturbance. To address this issue, this study develops an integrated framework with three core contributions: a minimal-lead-disconnection induced-voltage testing topology, a boundary-specific engineering-equivalent parasitic-capacitance model, and a terminal-referred phasor-based power-supply capacity-calibration method. Under the proposed testing topology, single-phase power-frequency excitation is applied on the valve side, and the induced-voltage response is established at the grid-side bushings while some of the restored auxiliary-equipment connections are retained. Considering the parasitic capacitance introduced by valve towers, tubular busbars, grading fittings, and grid-side auxiliary devices under the minimal-lead-disconnection boundary, an engineering equivalent model for extracting the valve-side stray capacitance is developed based on quasi-static electric field theory, geometric-envelope dimensional reduction, and conformal-mapping-based edge correction. The grid-side equivalent capacitance is further obtained using equipment parameters. On this basis, the induced-voltage distribution under the interconnection of multiple converter transformers is analyzed, and a power-supply capacity-calibration method considering the phasor relationship between inductive excitation current and capacitive current is established. Pre-test calculations yield a valve-side stray capacitance of 0.96 nF and a grid-side equivalent capacitance of 1.27 nF. When the grid-side induced voltage of phase C reaches 9.90 kV, the induced voltages of phases A and B are 4.56 kV and 5.14 kV, respectively, while the apparent power calculated from the field-measured RMS voltage and current is 1.34 kVA. The results verify the effectiveness of the proposed method for low-disturbance field testing and portable test-power-supply configuration. Full article

Stray cats may act as reservoirs of antimicrobial-resistant and potentially pathogenic bacteria, representing a potential public health concern within a One Health framework. This study investigated the occurrence of antimicrobial resistance (AMR), multidrug resistance (MDR), and virulence-associated traits in commensal Escherichia coli isolated from free-living cat colonies in southern Spain. A total of 169 rectal swabs were collected from cats belonging to feline colonies and shelters in Benalmádena (Málaga, Spain). Bacterial isolation and identification were performed using selective culture media, conventional biochemical tests, and MALDI-TOF mass spectrometry. Antimicrobial susceptibility was determined by minimum inhibitory concentration (MIC) testing against 15 antimicrobial agents, and isolates were screened for selected virulence-associated genes associated with major diarrheagenic E. coli pathotypes. A total of 68 E. coli isolates (40.2%) were recovered. The highest resistance frequencies were observed for sulfamethoxazole (25.0%) and ampicillin (20.6%), whereas all isolates showed high susceptibility rates to most of the antimicrobials tested, including azithromycin (100%), as well as gentamicin, amikacin, cefotaxime, ceftazidime, meropenem, colistin, chloramphenicol and tigecycline (98.5%). Six isolates (8.8%) were classified as multidrug-resistant. In addition, six isolates (8.8%) were identified as atypical enteropathogenic E. coli (aEPEC), although none exhibited a multidrug resistance phenotype. These findings demonstrate the presence of both AMR and virulence-associated traits among commensal E. coli circulating in free-living cats. The inclusion of feline colonies or shelters in AMR surveillance programmes may contribute valuable information for integrated One Health monitoring strategies. Full article

Solar-induced chlorophyll fluorescence (SIF) provides a direct proxy for vegetation photosynthesis-related information; however, under stress conditions, its relationship with photosynthesis should be interpreted together with absorbed photosynthetically active radiation by chlorophyll (APAR_chl) and non-photochemical quenching (NPQ). This study presents a conceptual design of a compact dual-channel airborne imaging spectrometer for synchronous observation of SIF-related spectral radiance and broadband vegetation-canopy spectral reflectance (BR). A self-collimating shared-optical-path configuration is proposed to reduce the system volume, yielding a simulated optical envelope of 205 × 150 × 120 mm³. Optical simulations predict spectral resolutions better than 0.3 nm over 670–780 nm for the SIF channel and better than 2 nm over 400–780 nm for the BR channel. An asymmetric double Babinet depolarizer is incorporated to reduce polarization-related errors, and the simulated system polarization sensitivity is below 1%. The calculated stray-light ratios of the SIF and BR channels are 0.553% and 0.287%, respectively. LightTools was used to simulate the radiative transfer performance of the instrument under realistic scenes. Furthermore, an end-to-end SIF retrieval simulation was performed to evaluate the retrieval capability of the proposed system. The results indicate that the proposed concept is theoretically feasible and may support future quantitative SIF retrieval and the interpretation of vegetation photosynthetic and stress-related processes. Full article

Background: Toxoplasmosis is a globally prevalent zoonotic infection caused by Toxoplasma gondii, with potentially severe consequences for pregnant women, foetuses, and immunocompromised individuals. Despite its public health importance, epidemiological data on T. gondii infection in Kuwait remain limited and restricted to selected population groups. This study assessed the seroprevalence of T. gondii among community-based adult participants in Kuwait and examined potentially associated risk factors. Methods: A cross-sectional study was conducted in September 2024 in Kuwait City and Jahra governorates. Serum samples from a convenience sample of 200 adults attending governmental polyclinics were screened for T. gondii IgM and IgG antibodies using VIDAS ELISAassays, with IgG-positive samples further analysed for IgG avidity. Demographic and exposure data were collected using structured questionnaires. Univariable and multivariable associations between demographic and exposure-related factors and IgG seropositivity were statistically evaluated. Results: The overall IgG seroprevalence was 11.5% (23/200), with no significant difference between governorates. All samples were IgM-negative, and all IgG-positive and equivocal samples showed high avidity. Age >40 years was associated with seropositivity in univariable analysis, but this association was not significant after adjustment (aOR = 2.21, 95% CI: 0.88–5.89; p = 0.092). No significant associations were observed with sex, nationality, educational level, travel history, cat ownership, or contact with stray cats. Conclusions: Among the participating community-based adults in Kuwait, T. gondii seroprevalence was lower than that reported in several regional studies, with serological findings consistent with past rather than recent infection. No demographic or exposure-related factor was independently associated with seropositivity. Larger population-based studies specifically powered to investigate risk factors and incorporating dietary, occupational, environmental, and migration-related exposures are needed to better characterise transmission pathways and inform targeted One Health surveillance and prevention strategies. Full article

The impact of the oxide film in the remelted zone of a seed on the epitaxial solidification of single-crystal superalloys was investigated, with a specific focus on clarifying the hindrance mechanism of complex compositional oxide films during the epitaxial growth process. Experimental findings indicated that the oxide film was composed of multiple constituents, such as WO₃ and Al₂O₃, and displayed no remarkable texture in its crystal orientation. The formation mechanism of coherent oxides during the alloy oxidation process and their potential as nucleation sites for solidification were analyzed. Owing to disparities in symmetry along the growth direction, the γ phase formed through oxide nucleation that deviated from its original orientation. Moreover, the existence of polycrystalline oxide films impeded the effective transfer of single-crystal seed orientation information, leading the epitaxial growth to mainly rely on the mechanism where dendrites penetrate through the damaged areas of the oxide film to reach the upper region. Significantly, aluminum oxide within the oxide film could act as new nucleation sites, potentially triggering the formation of stray grains in the central region of the casting. Full article

Severe electrochemical corrosion and leaching degradation of underground structures are induced by coupled stray current and groundwater in rail transit systems like subways. The microstructural evolution of fly ash geopolymer (FAG) during accelerated leaching was systematically investigated by simulating a coupled direct current (DC) stray current and soft water environment. Pore solution alkalinity and electrolytic cell OH⁻ concentration were utilized as evaluation indicators, combined with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). Results indicate that substantial OH⁻ leaching occurs under the coupled stray-current and soft-water exposure, leading to reduced pore-solution alkalinity and changes consistent with the degradation of the N–A–S–H binding network. Consequently, porosity, most probable pore diameter, and the quantity of harmful pores are increased. However, no obvious changes in the major diffraction peaks associated with quartz and mullite were detected within the resolution of the qualitative XRD analysis. Furthermore, a linearly decreasing trend over time is observed for the coupled leaching rate. Mix proportion analysis demonstrates that FAG leaching resistance is improved by reducing the water-to-binder ratio; specifically, superior gel phase content and pore structure are maintained at a ratio of 0.30. Additionally, cumulative OH⁻ leaching is effectively reduced by decreasing the sodium silicate modulus, with optimal resistance exhibited between 1.0 and 1.2. Concurrently, pore solution alkalinity before and after leaching is significantly elevated by increasing the alkali dosage. This exerts a pronounced inhibitory effect on OH⁻ leaching, thereby substantially enhancing the overall leaching resistance. Full article