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The technology of heat-assisted magnetic recording (HAMR) has improved the storage density of hard disc drives. The PFPE molecules of lubricant layer adhered on the disc can transfer from the lubricant layer and form the lubricant bridge which can deteriorate the stability of read/write process. In this paper, the formation and breaking of lubricant bridge at the head–disc interface (HDI) affects HAMR stability and deserves to be investigated. Using molecular dynamic simulation, a full-atom model was built to evaluate the behaviour of the lubricant bridge. Moreover, the effects of lubricant temperature, heating-up time, disc rotation speed and bearing pressure on the HDI were studied. It has been found that the amount of transferring atoms sharply increased when the lubricant temperature was above 700 K. The loss rate of lubricant layer decreased gradually during the heating process and it took about 2.2 ns for the remaining lubricant to reach stability. Furthermore, transferring PFPE molecules can form the lubricant bridge. A shorter heating-up time makes the lubricant bridge thicker and more robust. And the duration of lubricant bridge is notably affected by heating-up time, rotation speed and bearing pressure. A shorter heating-up time leads to a longer duration of lubricant bridge, whereas a higher rotation speed and bearing pressure reduces the duration of lubricant bridge. [ABSTRACT FROM PUBLISHER]

The presence of particles, which can intrude into the gas bearing, is one of the most common factors in the failure of hard disk drives (HDDs). Previous works investigated particle trajectories inside air-filled drives without considering temperature effects on the distribution of particles. Actually, especially for the submicron particle, particle trajectories and trapping status are affected by the temperature gradient since the thermophoretic force cannot be ignored. In this paper, considering major heat generation components such as the spindle motor and voice coil motor (VCM), trajectories and trapping status for AlO particles inside a 2.5 inch helium-filled drive are simulated by the commercial computational fluid dynamics solver FLUENT with user-defined functions (UDFs). The trapping criterion for AlO particles is used as boundary conditions for different colliding surfaces. The results reveal that particles in the air-filled drive will more likely degrade the head-disk interface (HDI) reliability. In addition, after considering the temperature, the particle trapping rate by the disk decreases both inside the air-filled drive and the helium-filled drive. And its reduction inside the air-filled drive is larger. Moreover, small particles will more likely degrade the HDI reliability since they can follow the rotatory flow well and have more chance to collide with the disk surface, and then easily attach onto the disk surface. [ABSTRACT FROM AUTHOR]

Currently, heat-assisted magnetic recording (HAMR) technology has been proposed as a method for enabling higher storage density. In this paper, the molecular dynamic simulation method was used to investigate the consumption and recovery of the lubricant perfluoropolyether (PFPE) layer under rapid heating and cooling through HAMR. A full-atom model for the 3-D slider-lubricants-disk substrate system was built for this paper. The lubricant adheres to the diamond-like carbon substrate, and the space between the slider and the lubricant is filled with helium atoms. It is found that HAMR laser heating results in the gradual consumption of the PFPE lubricant, and that the target operational temperature T0 significantly affects the consumption of the PFPE lubricant on the disk substrate. The extent of lubricant consumption increases sharply when T0 is above 600 K. The lubricant’s weight percentage on the disk substrate rises up again when cooling occurs. But it cannot be completely recovered. On the other hand, the bearing pressure reduces the degree of consumption of the PFPE lubricant by laser heating. However, the effect of bearing pressure on the amount of remaining PFPE lubricant becomes weak when T0 is above 800 K. [ABSTRACT FROM AUTHOR]

The lubricant bridge connecting the slider and the disk will significantly deteriorate the read–write stability of the hard disk drive. This paper builds a model of disk-lubricant-slider system. The coarse-grained bead-spring model is used to represent perfluoropolyethers molecules. And the molecular dynamic method is used to study the formation time and the molecule number of the lubricant bridge under different disk rotation speeds and slider flying heights. Furthermore, the influence of lubricant bridge on the pressure acting on the slider pad is also studied. [ABSTRACT FROM AUTHOR]

Previous works investigated particle trajectories in hard disk drives (HDDs) with the actuator arm and the head gimbals assembly at a fixed position. Actually, internal fluid field characteristics of HDDs can be greatly changed by the arm swing during track-seeking operations, which can affect particle trajectories and trapping status. In this paper, using the dynamic mesh method in a 2.5 in HDD for the first time considers the arm swing in the computational fluid dynamics (CFD) simulation. Al2O3 particle trajectories in this HDD are studied by the CFD solver FLUENT with user-defined functions. The trapping criterion for Al2O3 particles is used as a boundary condition for colliding surfaces. Simulation results reveal that the particle undergoes a larger number of collisions with the disk surface for the average seek time of 12 ms than for the average seek time of 6 ms. In addition, the faster the arm swings, the larger the number of particles that gather near the arm, and the shorter time it will take for particles to be trapped. Moreover, particle-surface collisions can successively take place many times in the helium flow. Furthermore, the particles are trapped slower in the helium-filled drive than in the air-filled drive. [ABSTRACT FROM AUTHOR]

This article presents a reverse modeling of the headform when wearing a filtering facepiece respirator (FFR) and a computational fluid dynamics (CFD) simulation based on the modeling. The whole model containing the upper respiratory airway, headform, and FFR was directly recorded by computed tomography (CT) scanning, and a medical contrast medium was used to make the FFR “visible.” The FFR was normally worn by the subject during CT scanning so that the actual deformation of both the FFR and the face muscles during contact can be objectively conserved. The reverse modeling approach was introduced to rebuild the geometric model and convert it into a CFD solvable model. In this model, we conducted a transient numerical simulation of air flow containing carbon dioxide, thermal dynamics, and pressure and wall shear stress distribution in the respiratory system taking into consideration an individual wearing a FFR. The breathing cycle was described as a time-dependent profile of the air velocity through the respiratory airway. The result shows that wearing the N95 FFR results in CO2accumulation, an increase in temperature and pressure elevation inside the FFR cavity. The volume fraction of CO2reaches 1.2% after 7 breathing cycles and then is maintained at 3.04% on average. The wearers re-inhale excessive CO2in every breathing cycle from the FFR cavity. The air temperature in the FFR cavity increases rapidly at first and then stays close to the exhaled temperature. Compared to not wearing an FFR, wearers have to increase approximately 90 Pa more pressure to keep the same breathing flow rate of 30.54 L/min after wearing an FFR. The nasal vestibule bears more wall shear stress than any other area in the airway. [ABSTRACT FROM AUTHOR]

Fibrous media is the most common method of filtration, which is generally characterized by its pressure drop and filtration efficiency. In this work, the computational fluid dynamics (CFD) technology was applied to simulate the filtration performance of multi–fiber filters. The pressure drop and filtration efficiency with different fiber arrangements, fiber diameters, face velocities and particle sizes were studied. It was found that filtration efficiency changed with the face velocity for different particle sizes. The layered structures with the same fiber diameters and total solid volume fraction (SVF) were compared, indicating that the dense–sparse structure had the highest filtration efficiency for all the simulated particle sizes at the cost of high pressure drop. Then the dense–sparse structure was optimized to achieve a better filtration performance by using less tiny fibers in the front–row and removing some fibers in the back–row. [ABSTRACT FROM AUTHOR]

It has been reported that high corticosterone level could damage the normal hippocampal neurons both in vitro and in vivo. Furthermore, high concentration of corticosterone induced impair in PC12 cells has been widely used as in vitro model to screen neuroprotective agents. Cajaninstilbene acid (CSA), a natural stilbene isolated from Cajanus cajan leaves, has various activities. In present study, we investigated the effect of CSA on corticosterone-induced cell apoptosis and explored its possible signaling pathways in PC12 cells. We demonstrated that pretreatment with CSA at the concentrations of 1–8 μmol/L remarkably reduced the cytotoxicity induced by 200 μmol/L of corticosterone in PC12 cells by MTT, and further confirmed the neuroprotection by Hoechst 33342 and PI double staining and lactate dehydrogenase release (LDH) assay at the concentration of 8 μmol/L. Moreover, the cytoprotection of CSA was proved to be associated with the homeostasis of intracellular Ca 2+ , relieving corticosterone-induced oxidative stress by decreasing the contents of ROS and malondialdehyde (MDA), increasing the activities of superoxide dismutase (SOD) and catalase (CAT), and the stabilization of ER stress via down-regulating the expression of ER chaperone protein glucose-regulated protein 78 (GRP78), ER stress associated transcription factor C/EBP homologous protein (CHOP/GADD153), and the X box-binding protein-1 (XBP-1), as well as the expression of ER stress-specific protein caspase-12 and its downstream protein caspase-9. Considering all the findings, it is suggested that the neuroprotective activity of CSA against the impairment induced by corticosterone in PC12 cells was through the inhibition of oxidative stress and ER stress-mediated pathway. [ABSTRACT FROM AUTHOR]

In this paper, a heater-slit design was investigated to reduce the crosstalk effects of thermal track positioning control (TPC) heating on the thermal flying height control, using a coupling thermal-structural simulation and air-bearing simulation. The results show that the slit design helps to achieve a large head displacement along crosstrack direction and flying height reduction at head elements, due to the reduction of the mechanical constraints on the thermally induced expansion of the slider body. The undesirable flying height reduction at side edge of trailing pad of the slider can be improved by further optimization of slit design. Thus, the heater-slit design overcomes the limitation on the air-bearing surface design for TPC slider. [ABSTRACT FROM AUTHOR]

• This paper first applies EI-TOF to the additive manufacturing process. • This paper is the first to monitor atmospheric composition during the L-DED process. • The degree of variation of the gases significantly changed with the laser power. Laser-based Directed Energy Deposition (L-DED) is a promising additive manufacturing technology, which has broad application prospects and practical value in many fields. The nondestructive testing technology of L-DED work piece quality monitoring requires high accuracy and capability for real-time process. This work developed an online monitoring system based on a miniature electron impact ion source time-of-flight mass spectrometer (EI-TOF) and a high-speed camera, which monitored the atmosphere above the molten pool area. The number of spatters was measured using a high-speed camera. The composition of the samples and spatters was measured by using element analyzer, inductively coupled plasma mass spectrometry, and electron spectroscopy. The variation in the atmosphere was measured using EI-TOF, and the results confirmed that the O 2 , N 2 and H 2 O content decreased during the L-DED process. At the laser power of 400 W, the oxygen consumptions were 92.5% and 86.4% compared with those at the laser power of 500 W and 600 W, respectively. During the L-DED process, the number of spatters decreased when the laser power was increased from 400 W to 600 W. And at the laser power of 600 W, the average number of spatters was reduced to 59.3% compared with the laser power of 400 W. It can be found that dust contained a large amount of virgin powder and little spatters. It also can be found that at the laser power of 400 W, 500 W and 600 W, the amount of oxygen in the dust was 0.544%, 0.242% and 0.159%, respectively. The relative content of oxygen in the cross section of the seam was 35.58%, 43.79% and 44.30%, respectively. The deviation of the monitoring results (H 2 O, N 2 , O 2) are significant at the same power when different materials was used as the substrate. [ABSTRACT FROM AUTHOR]

Perillyl alcohol (POH), a natural monoterpene, exhibits potent anticancer activity and may also play a role in inhibiting plant pathogens. However, its mechanism of action on controlling gray mold of tomato remains unclear. In this study, we investigated the effect of POH on Botrytis cinerea infected tomato. The results demonstrate that POH inhibits the in vitro growth of B. cinerea by disrupting plasma membrane integrity, thereby exhibiting broad-spectrum antimicrobial activity. Metabolomic analysis revealed that POH activated jasmonic acid (JA) biosynthesis and induced JA production in B. cinerea -treated tomato. Furthermore, POH upregulated the expression of defense-related genes and induced ROS accumulation. Specifically, POH induced the accumulation of kaempferol in tomato and exogenous kaempferol disrupted the plasma membrane of B. cinerea and induced ROS production. Taken together, POH can inhibit the development of gray mold, besides enhancing plant immunity against B. cinerea by inducing JA accumulation and promoting kaempferol biosynthesis. • POH activates jasmonic acid biosynthesis and induces JA production. • POH upregulates the expression of resistance genes and induces ROS accumulation. • Kaempferol exhibits antimicrobial activity against B. cinerea. [ABSTRACT FROM AUTHOR]

• A new in-situ monitoring system was proposed to upscale resolution and extract geometric characteristics during AM process. • The proposed ViTSR performs better than the SOTA methods in terms of PSNR, which may reduce the cost of high-speed camera. • The molten pool and plasma arc can be simultaneously and accurately extracted by FCN with input of reconstructed frames. • The low-cost AI edge board reduces the inference time of ViTSR to 50.97 ms, which reduce the cost of computing in AM process. In additive manufacturing (AM), in-situ monitoring systems are vital for ensuring process quality. However, the widespread adoption of traditional high-speed camera-based monitoring systems is hindered by the prohibitively high cost of the required high-speed cameras. This paper introduces an innovative low-cost in-situ monitoring system that utilizes AI edge computing boards to expedite digital image processing without requiring high resolution (HR) video sequences. The system integrates a visual transformer-based video super resolution (ViTSR) network for reconstructing high resolution video frames and employs a fully convolutional network (FCN) to extract geometric characteristics of the molten pool and plasma arc simultaneously during AM processes. Comparing ViTSR with six state-of-the-art super-resolution methods, it achieved the highest peak signal-to-noise ratio (PSNR) of 38.16 dB on the test data. Moreover, the FCN utilized the reconstruction results from ViTSR, demonstrating an accuracy of 96.34% in multi-object extraction tasks. Through operator fusion and model pruning, the inference time of ViTSR and FCN on the AI edge board is optimized to 50.97 ms and 67.86 ms, respectively. Consequently, the proposed system achieves a total inference time of 118.83 ms, meeting the real-time quality monitoring needs of AM processes. Furthermore, this approach effectively reduces the expenses associated with high-speed camera-based monitoring systems, thereby promoting the widespread adoption of in-situ monitoring systems within the realm of AM. [ABSTRACT FROM AUTHOR]

Malaria continues to pose a serious global health threat, and artemisinin remains the core drug for global malaria control. However, the situation of malaria resistance has become increasingly severe due to the emergence and spread of artemisinin resistance. In recent years, significant progress has been made in understanding the mechanism of action (MoA) of artemisinin. Prior research on the MoA of artemisinin mainly focused on covalently bound targets that are alkylated by artemisinin‐free radicals. However, less attention has been given to the reversible noncovalent binding targets, and there is a paucity of information regarding artemisinin targets at different life cycle stages of the parasite. In this study, we identified the protein targets of artemisinin at different stages of the parasite's intraerythrocytic developmental cycle using a photoaffinity probe. Our findings demonstrate that artemisinin interacts with parasite proteins in vivo through both covalent and noncovalent modes. Extensive mechanistic studies were then conducted by integrating target validation, phenotypic studies, and untargeted metabolomics. The results suggest that protein synthesis, glycolysis, and oxidative homeostasis are critically involved in the antimalarial activities of artemisinin. In summary, this study provides fresh insights into the mechanisms underlying artemisinin's antimalarial effects and its protein targets. Highlights: We identified the targets of artemisinin at different stages of the intraerythrocytic cycle of Plasmodium falciparum using a photoaffinity probe of artemisinin.Artemisinin can interact with parasite proteins in vivo through both covalent and noncovalent mechanisms.Artemisinin may exert its antimalarial effects by interfering with the parasite's protein synthesis, glycolysis, and oxidative homeostasis pathways.This study provides fresh insights into the mechanisms underlying artemisinin's antimalarial effects and its protein targets. [ABSTRACT FROM AUTHOR]

It is common for people to use N95 filtering facepiece respirators (FFRs) in daily life, especially in locations where particulate matter (PM2.5) concentration is rising. Wearing N95 FFRs is helpful to reduce inhalation of PM2.5. Although N95 FFRs block at least 95% of particles from the atmosphere, the deadspace of N95 FFRs could be a warm, wet environment that may be a perfect breeding ground for bacterial growth. This work studies the micro-climate features including the temperature distribution and water vapor condensation in the deadspace of an N95 FFR using the computational fluid dynamics (CFD) method. Then, the temperature and relative humidity inside the same type of N95 FFR are experimentally measured. There is a good agreement between the simulation and experimental results. Moreover, an experiment is conducted to study the distribution of bacteria sampled from the inner surface of an N95 FFR after donning. [ABSTRACT FROM AUTHOR]

• A method of 3D reconstruction for LPBF parts by light field camera is proposed. • Simple and high-precision calibration is achieved by the consistency method. • A LFEPI-Unet is designed for accuracy disparity reconstruction. • Accurately mapping of disparity, depth, and 3D spatial coordinates is established. • First-time application for in situ 3D reconstruction and monitoring of LPBF parts. The assessment of output quality in the laser powder bed fusion process entails the analysis of the three-dimensional morphology of the manufactured parts, which plays a crucial role in quality control to prevent metallurgical defects. This study proposes a novel approach of three-dimensional reconstruction for laser powder bed fusion parts using a light field camera. Initially, a consistency method for high-precision camera calibration was explored to determine the virtual camera pixel size and coefficient of effective focal length of light field camera. Subsequently, the model based light field epipolar-plane image Unet is designed to obtain disparity information without any data augmentation techniques. By leveraging both binocular and light field optical paths, a robust mapping relationship of the disparity, depth, and visually coherent three-dimensional contour was established. Finally, the three-dimensional contours of laser powder bed fusion parts were reconstructed by the established mapping with a single exposure of the light field camera. The proposed method enables three-dimensional contour visualization of laser powder bed fusion parts from multi-view perspectives, which facilitates in situ monitoring of the spattering distance, three-dimensional spatial points and lines of the printed layers and contours of printed parts. With a calibration error of 50 μm and resolution of 180 μm for the light field camera (Lytro illum camera), the maximum relative and absolute errors between reconstructed three-dimensional spatial points were 4.33 % and 260 μm respectively when compared with theoretical dimension, and 0.5 % and 210 μm respectively when compared with manufactured dimension. The maximum root-mean-square error of reconstructed three-dimensional contour surfaces was found to be 1.55 mm. This study represents the first application of a light field camera for in situ three-dimensional reconstruction of laser powder bed fusion parts, which notably can be obtained from only a single round of calibration and exposure, enabling seamless monitoring of their surface morphology and facilitating online quality control. These advancements have vast potential for enhancing high-end additive manufacturing. [ABSTRACT FROM AUTHOR]

• LSP was applied on the 50CrVA alloy to improve the mechanical properties. • Propagation characteristic of shock wave was investigated. • Influence of laser energy and spot diameter on residual stress was revealed. • Optimized process parameter and strength enhancement were obtained by LSP. Laser shock peening (LSP) was implemented to treat aircraft landing gear 50CrVA alloy to improve mechanical properties. The sensitivity investigations of time step and mesh size were used to benchmark the 3D finite element method (FEM) model. Based on the established FEM model, the dynamic propagation characteristics of the shock wave inside the sample were predicted. The influence of laser energy and spot diameter on the residual stress field was further investigated. The numerical results indicate that regulating two critical LSP parameters can effectively improve the compressive residual stress (CRS) of metals, and the spot diameter has a greater effect than the laser energy in improving the uniformity of the CRS distribution. After that, the influences of LSP on the CRS field, microstructure, and mechanical properties were experimentally studied. After LSP treatment, the surface CRS reached 494.8 ± 31.8 MPa with an affected depth of about 400 μm. The phase composition was not changed by LSP treatment, but it weakened texture strength and refines grains. Under the impact of grain refinement and CRS, the average surface microhardness of the 50CrVA alloy reached 355 HV, indicating an increase up to 5.3 %. The ultimate tensile strength and yield strength were increased by 11.3 % and 14.5 %, respectively, which were in contrast to the unchanged elongation. This work verifies the feasibility of mechanical properties enhancement of 50CrVA alloy by LSP. [ABSTRACT FROM AUTHOR]

An entrapped particle on the slider's air bearing damages the surface of the slider or the disk. The study of particle movement on and the particle adhesion mechanism onto the slider surface is critical to reduce entrapped particle-induced damage. In this paper, we proposed a dynamical model of the adhesive particle's secondary migration on the slider surface. The model predicts whether the adhered particle will remain static by the action of the aerodynamic and adhesion forces. There are three migration movement styles which are rolling, sliding and lifting away from the original adhered location. Further, particle rolling migration behaviors on the slider air bearing surface (ABS) are analyzed considering the effects of flow shear rate, particle diameter and properties. Finally, the particle migration trajectory and velocity with time on the investigated slider are presented. It was found that most particles that adhere to the slider surface remain static for the investigated slider; pure rolling motion on the slider ABS is the main migration styles. The particle with a larger diameter and air shear rate speeds up to a higher velocity, and it takes more time to speed up to the constant velocity. A particle's secondary migration motion can be observed for the particle that adheres to the slider recession region and trailing pad. Then the particle enters airflow blowing out of or rolls away from the head-disk interface. [ABSTRACT FROM AUTHOR]

The complex co-doping structure of boron and sulfur is investigated using the density functional theory approach. Different ratio models show significant differences in electronic properties. More importantly, the interactions of boron, sulfur, and carbon atoms are studied on intrinsic/B-doped (001), (111), and (110) diamond surfaces. The most stable adsorption site, adsorption structure, and charge transfer are discussed. B atom induces a larger adsorption energy (intrinsic: −4.57 eV, −4.56 eV, and −4.00 eV; B-doped: −4.70 eV, −4.72 eV, and −4.86 eV). And a larger charge transfer between diamond and S radicals is also found. Therefore, the phenomenon that the sulfur contents in diamond increases after the introduction of boron in the experiment can be explained. Considering different crystal surfaces, larger adsorption strength is obtained from (111) and (110) surface. And different levels of strain are introduced into three different surfaces. The migration barrier of S atom is also considered. The lowest migration barrier is 0.06 eV on (111) surface, whereas the highest value is found on (001) surface (1.96 eV). B atom also benefits for the H x S radical adsorption. It can be concluded that B doping can help with S and H x S adsorption. This study can provide an explanation for the increased solubility of S on B-doped diamond. [Display omitted] • Theoretical research was conducted on atom interaction mechanism of B, S, and C on three diamond surfaces. • The qualitative explanation was offered for doping property of B-S co-doping by the B and S ratio model (like 2:1). • For the first time, mutual promotion of B and S atoms in doping diamond was explained by simulations. • The migrations of the atom were analyzed with lowest migration barrier (0.06 eV) was discovered. [ABSTRACT FROM AUTHOR]

Although diamond seeds are generally polished before growth, the effect of surface roughness of diamond seeds on crystal growth quality is rarely studied. In this research, three diamond seeds were prepared for researching the effect of surface roughness of diamond seed. They were made by cutting a bulk diamond and subsequently suffered partially polished, totally polished and unpolished, respectively. After a period of microwave plasma chemical vapor deposition growth, various tests were carried out on the samples. According to the microscope and step profiler, the surface roughness of diamond seed did not affect the surface roughness of long-term growth diamonds. Compared by Raman spectra, ultraviolet − visible and infra-red spectra, it indicated that a certain rough surface of diamond seed could improve the internal stress of diamond, but reduce the crystalline quality slightly. Moreover, the surface roughness had almost no impact on the optical properties of the diamond. As a result, diamond seeds with low roughness after cutting could be used for direct growth without polishing, bringing on significant economic for gem-quality diamond production. [ABSTRACT FROM AUTHOR]

In the field of machine learning (ML) and data science, it is meaningful to use the advantages of ML to create reliable interatomic potentials. Deep potential molecular dynamics (DEEPMD) are one of the most useful methods to create interatomic potentials. Among ceramic materials, amorphous silicon nitride (SiNx) features good electrical insulation, abrasion resistance, and mechanical strength, which is widely applied in industries. In our work, a neural network potential (NNP) for SiNx was created based on DEEPMD, and the NNP is confirmed to be applicable to the SiNx model. The tensile tests were simulated to compare the mechanical properties of SiNx with different compositions based on the molecular dynamic method coupled with NNP. Among these SiNx, Si3N4 has the largest elastic modulus (E) and yield stress (σs), showing the desired mechanical strength owing to the largest coordination numbers (CN) and radial distribution function (RDF). The RDFs and CNs decrease with the increase of x; meanwhile, E and σs of SiNx decrease when the proportion of Si increases. It can be concluded that the ratio of nitrogen to silicon can reflect the RDFs and CNs in micro level and macro mechanical properties of SiNx to a large extent. [ABSTRACT FROM AUTHOR]

Heat-assisted magnetic recording (HAMR) is a new approach, which makes the head write data easily under a low magnetic field using a laser to heat the magnetic media to reduce its coercivity, thus, it is considered to be the next generation of higher recording areal density technology. In this paper, a three-dimensional HAMR finite-element model of hard disk drive (HDD) is developed. The temperature distributions around the laser-heating area on disk surface are investigated when the HDD is filled with air and helium. The cooling effects of the disk rotation and the heat convection in head-disk interface (HDI) are also analyzed. [ABSTRACT FROM AUTHOR]

Plasma arc additive manufacturing (PAM) is an additive manufacturing technology that has been widely used in the past and has practical applications in many fields. The non-destructive testing methodology of PAM workpiece quality monitoring requires high level of accuracy and real-time capability. The characteristics of the melt pool and plasma arc are the keys to characterizing the dynamic manufacturing process during the powder feed PAM process, allowing for process prediction and real-time feedback control. This paper describes a new image recognition system that uses a fully convolutional network (FCN) to acquire melt pool and plasma arc morphologies simultaneously. Its image segmentation performance is compared with four conventional methods and three artificial intelligence methods. Results show that the FCN method can extract melt pool and plasma arc quickly and accurately, even in a complex manufacturing environment. The image segmentation-based FCN's accuracy is 95.1%, and the average processing time is only 84 ms, according to the results. The performance is far superior to the existing seven methods. The relationship between average captured areas (melt pool and plasma arc) and parameters of the plasma arc (current intensity and scanning speed) is then analyzed. Finally, the quality of products in terms of sample surface roughness is measured, and its relationship with the average areas of the melt pool and plasma arc is clarified. [ABSTRACT FROM AUTHOR]

Glycyrrhetinic acid (GA) shows great efficiency against non-small cell lung cancer (NSCLC), but the detailed mechanism is unclear, which has limited its clinical application. Herein, we investigated the potential targets of GA against NSCLC by activity-based protein profiling (ABPP) technology and the combination of histopathology and proteomics validation. In vitro and in vivo results indicated GA significantly inhibited NSCLC via promotion of peroxiredoxin-6 (Prdx6) and caspase-3 (Casp3)-mediated mitochondrial apoptosis. This original finding will provide theoretical and data support to improve the treatment of NSCLC with the application of GA. [Display omitted] • First-time integrated analysis profiling of non-small cell lung cancer (NSCLC) and Glycyrrhetinic acid (GA) treatment by integrating activity-based protein profiling (ABPP) technology, histopathology and proteomics validation both in vitro and in vivo. • Identification of GA promoted ROS accumulation and inhibited proliferation of NSCLC cells. • Identification of Casp3 and Prdx6 were direct target proteins of GA in the treatment of NSCLC cells. [ABSTRACT FROM AUTHOR]

The efficient and precise acquisition of hydrodynamic results in complex interaction scenarios for unmanned underwater vehicles (UUVs) presents a significant challenge. This study proposes a time-sequenced hydrodynamics prediction system of underwater vehicle based artificial intelligence edge computing. Firstly, a SE-CausalNet framework is proposed and a hydrodynamic prediction system for underwater vehicles is developed based on a neuromorphic computing chip. Secondly, the computational fluid dynamics (CFD) results of the Remus UUV are validated with experimental data. Two UUV motion cases are proposed to further elucidate hydrodynamics characteristics under the complex interference of submarines. Finally, the hydrodynamics of the UUV for two motion cases is analyzed, and four datasets are constructed to fully demonstrate the predictive capability of the system. Results show that the pressure field for the free offset path case differs remarkably from that of the fixed path case, and noticeable deviations are observed in both horizontal and vertical planes from the original fixed trajectory of the UUV. The prediction aligns well with CFD results, with a sample inference time within 0.3 s. The mean squared error of the four datasets is all below 2.6 × 10−4, indicating a rapid and highly accurate assessment of disturbance moments and trajectories. • The hydrodynamics characteristics of UUV during interactions with a submarine are investigated. • A hydrodynamics prediction system based on AI edge computing platform is developed. • It provides valuable insights to guide the design and motion control of UUVs. [ABSTRACT FROM AUTHOR]

• A multiphysics simulation model of LU inspection is established. • Propagation characteristics of excited ultrasonic waves in different LPBF alloys is studied. • Interaction between ultrasonic waves and submillimeter artificial defects is investigated. • Four typical LPBF alloys are fabricated and measured by the LU through-transmission inspection. In the development of additive manufacturing (AM) technology, laser powder bed fusion (LPBF) is one of the important processing methods. However, the hole defects in the fabricated samples limit the development. Laser ultrasonic (LU) technology plays a major role in the detection of LPBF parts with tiny defects, which has the advantages of non-contact and non-destructive. In this work, the detection of submillimeter internal defects in four typical LPBF alloys by LU technology is studied numerically and experimentally. A multiphysics simulation model of LU detection is established to investigate the propagation characteristics of excited ultrasonic waves in different LPBF alloys and their interaction with submillimeter artificial defects. Simulation results show that the amplitude of longitudinal (L) wave at the defect is the largest in AlSi10Mg alloy, and the amplitude of L wave in the 316L alloy, Ti6Al4V alloy and In718 alloy are very close, but their phases are slightly different. The amplitude of L wave tends to decrease nearly linearly with the increase in defect diameter. Then, four typical LPBF alloys are fabricated and measured by the LU through-transmission detection. The geometric information of artificial holes with a diameter larger than 0.2 mm are clearly characterized by the LU C-scan results, indicating the prominent applicability and feasibility of LU detection on different materials fabricated by LPBF. [ABSTRACT FROM AUTHOR]