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The near-dry electrical discharge machining processes have been conducted using air-mist or gas mist as a dielectric fluid to minimize the environmental impacts. In this article, near-dry electrical discharge machining (NDEDM) experiments have been performed to improve machining performance using an oxygen-mist dielectric fluid, a copper composite electrode, and Cu-Al-Be polycrystalline shape memory alloy (SMA) work materials. The copper composite electrode is made up of 12 wt% silicon carbide and 9 wt% graphite particles. The oxygen-mist pressure (Op), pulse on time (Ton), spark current (Ip), gap voltage (Gv), and flow rate of mixed water (Fr) were used as process parameters, and the material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) were used as performance characteristics. The global optimal alternative solution has been predicted by the PROMETHEE-II (Preference Ranking Organization METhod for Enrichment Evaluations-II) optimization technique. The best combinations of process parameters have been used to examine the microstructure of composite tools and SMA-machined surfaces by scanning electron microscopy (SEM) analysis. The best global optimum settings (oP: 9 bar, Ip: 60 µs, Ip: 12 A, Gv: 40 V, and Fr: 12 ml/min) are predicted to attain optimum machining performance (MRR: 39.049 g/min, TWR: 1.586 g/min, and SR: 1.78 µm). The tool wear rate of the NDEDM process has been significantly reduced by the copper composite electrode due to increasing microhardness, wear resistance, and melting point. When compared to the pure copper electrode tool, the MRR of NDEDM is improved to 21.91%, while the TWR and SR are reduced to 46.66% and 35.02%, respectively.

[...] the tendency for the mist to deposit on the top of the ridge.

Remote sensing images are widely used in object detection and tracking, military security, and other computer vision tasks. However, remote sensing images are often degraded by suspended aerosol in the air, especially under poor weather conditions, such as fog, haze, and mist. The quality of remote sensing images directly affect the normal operations of computer vision systems. As such, haze removal is a crucial and indispensable pre-processing step in remote sensing image processing. Additionally, most of the existing image dehazing methods are not applicable to all scenes, so the corresponding dehazed images may have varying degrees of color distortion. This paper proposes a novel atmospheric light estimation based dehazing algorithm to obtain high visual-quality remote sensing images. First, a differentiable function is used to train the parameters of a linear scene depth model for the scene depth map generation of remote sensing images. Second, the atmospheric light of each hazy remote sensing image is estimated by the corresponding scene depth map. Then, the corresponding transmission map is estimated on the basis of the estimated atmospheric light by a haze-lines model. Finally, according to the estimated atmospheric light and transmission map, an atmospheric scattering model is applied to remove haze from remote sensing images. The colors of the images dehazed by the proposed method are in line with the perception of human eyes in different scenes. A dataset with 100 remote sensing images from hazy scenes was built for testing. The performance of the proposed image dehazing method is confirmed by theoretical analysis and comparative experiments.

Bone grinding is an essential and vital procedure in most surgical operations. Currently, the insufficient cooling capacity of dry grinding, poor visibility of drip irrigation surgery area, and large grinding force leading to high grinding temperature are the technical bottlenecks of micro-grinding. A new micro-grinding process called ultrasonic vibration-assisted nanoparticle jet mist cooling (U-NJMC) is innovatively proposed to solve the technical problem. It combines the advantages of ultrasonic vibration (UV) and nanoparticle jet mist cooling (NJMC). Notwithstanding, the combined effect of multi parameter collaborative of U-NJMC on cooling has not been investigated. The grinding force, friction coefficient, specific grinding energy, and grinding temperature under dry, drip irrigation, UV, minimum quantity lubrication (MQL), NJMC, and U-NJMC micro-grinding were compared and analyzed. Results showed that the minimum normal grinding force and tangential grinding force of U-NJMC micro-grinding were 1.39 and 0.32 N, which were 75.1% and 82.9% less than those in dry grinding, respectively. The minimum friction coefficient and specific grinding energy were achieved using U-NJMC. Compared with dry, drip, UV, MQL, and NJMC grinding, the friction coefficient of U-NJMC was decreased by 31.3%, 17.0%, 19.0%, 9.8%, and 12.5%, respectively, and the specific grinding energy was decreased by 83.0%, 72.7%, 77.8%, 52.3%, and 64.7%, respectively. Compared with UV or NJMC alone, the grinding temperature of U-NJMC was decreased by 33.5% and 10.0%, respectively. These results showed that U-NJMC provides a novel approach for clinical surgical micro-grinding of biological bone.

In a semi-closed visualization pipeline, this experiment studied the inhibitory effect of ultra-fine pure water mist, ultra-fine water mist containing inorganic salt and ultra-fine water mist containing bacteria-inorganic salt on 9.8% methane explosion under five different quality of spray volume. Combined with the methane explosion suppression experiment, the ability of methane-oxidizing bacteria to degrade 9.8% of methane was studied in a simulated pipeline. Experiments showed that the addition of inorganic salt and the degradation of methane-oxidizing bacteria could improve the suppression explosion effect of ultra-fine water mist, and the suppression explosion effect was related to the volume of water mist. Under the same ultra-fine water mist condition, with the increase of the volume of water mist, the explosion suppression effect was improved. Compared with pure methane, pure water ultra-fine water mist, and inorganic salt ultra-fine water mist, the maximum explosion overpressure and flame propagation speed under the condition of bacteria-inorganic salt ultra-fine water mist were significantly reduced. Compared with the explosion of pure methane, due to the degradation of methane by methane-oxidizing bacteria, when the degradation time was 10 h, and the volume of ultra-fine water mist containing bacteria-inorganic salt was 12.5 mL, the maximum explosion overpressure dropped significantly from 0.663 to 0.343 MPa, a decrease of 48.27%. The appearance time of the maximum explosion overpressure was delayed from 208.8 to 222.6 ms. The peak flame velocity was 4 m s −1 , which was 83.3% lower than that of 9.8% pure methane explosion. This study will contribute to the development of efficient ultrafine water mist synergistic inhibitors for the prevention of methane explosion disasters.

In this research, the influences of cryogenically treated stainless steel grade 317 on the eco-friendly near-dry wire-cut electrical discharge machining (NDWEDM) processes have been investigated using the minimum quantity of water mixed with oxygen gas (oxygen mist) dielectric fluid. The stainless steel grade 317 has been applied to make the various biomedical and industrial components due to its high creep strength. The wire wear ratio (WWR) and cutting rate (CR) of NDWEDM are compared using cryogenically treated and untreated work materials by Taguchi’s analysis. The water flow rate, gas pressure, spark current, and pulse width had been considered as process parameters. The microstructure of wire electrode and machined surfaces of treated/untreated materials had been compared by scanning electron microscope (SEM) images. The WWR and CR of cryogenically treated materials in NDWEDM are 20.31% lower and 22.32% higher than untreated materials, respectively.

The use of mist nets is the most widespread technique to capture bats; however, no study has compared if the type of ground-level mist net used during sampling affects bat captures. We sampled bats using three different types of mist nets that varied in mesh (16, 18, and 20 mm) and denier/ply (45/1 and 75/2) sizes over 76 half-night surveys. We used 17–20 mist nets and checked them at intervals of 15–20 min. Capture rate for echolocating bats was higher in the two mist nets with the biggest denier/ply and smaller mesh sizes. “Ultrathin bat mist nets” showed the lowest capture rates (1.5 times less than “Regular bat mist nets”), whereas “Bird mist nets” had capture rates only 1.2 times smaller than “Regular bat mist nets.” Our results showed that “Bird mist nets” can sample echolocating bats almost as well as “Regular bat mist nets,” and that thinner mist nets may not be the best solution to capture bats that echolocate at high frequencies in this type of surveys. We highlight the importance of considering the efficiency, durability, and longevity of mist nets when choosing the ideal mist-net type for a bat survey.

Innovative techniques, such as environmental DNA (eDNA) metabarcoding, are now promoting broader biodiversity monitoring at unprecedented scales, because of the reduction in time, presumably lower cost, and methodological efficiency. Our goal was to assess the efficiency of established inventory techniques (live-trapping grids, pitfall traps, camera trapping, mist netting) as well as eDNA for detecting Amazonian mammals. For terrestrial small mammals, we used 32 live-trapping grids based on Sherman and Tomahawk traps (total effort of 10,368 trap-nights); in addition to 16 pitfall traps (1,408 trap-nights). For bats, we used mist nets at 8 sites (4,800 net hours). For medium and large mammals, we used 72 camera trap stations (5,208 camera-days). We identified vertebrate and mammal taxa based on eDNA analysis (12S region, with V05 and Mamm01 markers) from water samples, including a total of 11 3-km transects for stagnant water sampling and seven small streams for running water sampling. A total of 106 mammal species were recorded. Building on sample-based rarefaction and extrapolation curves, both trapping grids and pitfall were successful, recording 91.16% and 82.1% of the expected species for these techniques (~22 and ~9 species), and 16.98% and 6.60% of the total recorded mammal species, respectively. Mist nets recorded 83.2% of the expected bat species (~48), and 34.91% of the total recorded species. Camera trapping recorded 99.2% of the predicted large- and medium-sized species (~31), and 33.02% of the total recorded species. eDNA recorded 75.4% of the expected mammal species for this technique (~68), and 47.0% of the total recorded species. eDNA resulted in a useful tool that saves on effort and reduces sampling costs. This study is among the first to show the large potential of eDNA metabarcoding for assessing Amazonian mammal communities, providing, in combination with conventional techniques, a rapid overview of mammal diversity with broad applications to monitoring, management and conservation. By including appropriate genetic markers and updated reference databases, eDNA metabarcoding method can be extended to the whole vertebrate community.

Background and Objectives: The incidence of pyogenic spondylodiscitis has been increasing due to the aging of the population. Although surgical treatment is performed for refractory pyogenic spondylodiscitis, surgical invasiveness should be considered. Recent minimally invasive spine stabilization (MISt) using percutaneous pedicle screw (PPS) can be a less invasive approach. The purpose of this study was to evaluate surgical results and clinical outcomes after MISt with PPS for pyogenic spondylodiscitis. Materials and Methods: Clinical data of patients who underwent MISt with PPS for pyogenic spondylitis were analyzed. Results: Twenty-three patients (18 male, 5 female, mean age 67.0 years) were retrospectively enrolled. The mean follow-up period was 15.9 months after surgery. The causative organism was identified in 16 cases (69.6%). A mean number of fixed vertebrae was 4.1, and the estimated blood loss was 145.0 mL. MISt with PPS was successfully performed in 19 of 23 patients (82.6%). Four cases (17.4%) required additional anterior debridement and autologous iliac bone graft placement. CRP levels had become negative at an average of 28.4 days after surgery. There was no major perioperative complication and no screw or rod breakages during follow-up. Conclusions: MISt with PPS would be a less invasive approach for pyogenic spondylodiscitis in elderly or immunocompromised patients.

Key messageThe rapid seed germination of Caragana species adapted to arid environments is closely related to their high seed coat permeability, mist absorption, high GA promotion, and reduced ABA inhibition.Caragana species is adapted to a low-precipitation environment by rapid seed germination, and this trait has been widely used for afforestation in arid and semiarid regions of China. In this study, seed coat structure, water permeability, mist/dew absorption, gibberellin (GA), and abscisic acid (ABA) biosynthesis inhibitor on seed germination were measured and compared among six Caragana species growing in different mean annual precipitation (MAP) environments. The results showed that three Caragana species from low-MAP environments had a relatively loose seed epidermal cuticle structure, distinct tubular structure of the palisade layer between the epidermal cuticle and osteosclereids layer, high water permeability of the seed coat, rapid mist/dew absorption, rapid seed germination, and higher final germination rate. However, seeds of the three Caragana species from high-MAP environments had dense seed epidermal cuticle structures and lamellar tubular structures of the palisade layer between the epidermal cuticle and osteosclereids layer, and exhibited poor or scarce water permeability of the seed coat. Uniconazole, GA biosynthesis inhibitor, inhibited seed germination in C. korshinskii from low-MAP environments, and nordihydroguaiaretic acid and fluorenone, ABA synthesis inhibitors, prompted seed germination in C. stipitata from high-MAP environments. The findings suggest that the rapid seed germination of Caragana species is closely related to their high seed coat permeability, mist absorption, high GA promotion, and reduced ABA inhibition to adapt to low-MAP environments.