Generation Of Particles Research Articles

Preparation of phase change Heat storage wood with in-situ generation of thermal conductive particles to improve photothermal conversion efficiency

Wood has been developed with phase change heat storage function using balsa as a natural packaging material, and PEG was employed as a material for phase change heat storage (PCHS). Moreover, the thermal conductivity efficiency of the wood was be improved by in-situ synthesizing Fe3O4 in wood. The prepared PCHS wood was characterized by high solidification and melting enthalpies. The temperature of phase change ranged from 21.47 °C to 35.30 °C, consistent with the temperature range that makes humans comfortable in their body. The in-situ generation of Fe3O4 not only improves the PCHS wood's thermal conductivity efficiency, but also forms a 3D network structure with PCHS materials, thereby improving the dimensional stability. Comparing with original wood, PCHS wood shows good temperature regulation function, which can quickly convert light energy into internal energy and has a longer period of thermal radiation at low temperatures. The generated PCHS wood shows a promising application as indoor temperature regulating materials to promote building energy conservation.

Study of dust pollution control effect based on orthogonal test and CFD numerical simulations.

To control the diffusion of high concentrations of coal dust during tunnel boring and minimize the threat to the life and health of coal miners, theoretical analysis, numerical simulations, and field measurements were combined in this study. First, computational fluid dynamic simulation software was used to simulate the generation of dust particles and their transport pattern in the tunnel. Subsequently, an innovative orthogonal test was performed to study the effect of four ventilation parameters [the pressure airflow rate (Q), distance between the air duct center and heading face (LA), distance between the air duct center and tunnel floor (LB), and distance between the air duct center and nearest coal wall (LC)] on dust diffusion. According to the orthogonal test results, the optimal ventilation parameters for effective dust control are as follows: Q = 1400 m3/min, LA = 7 m, LB = 2.8 m, and LC = 1 m. The optimized set of ventilation parameters was applied to the Wangpo 3206 working face. The results show that dust diffusion in the tunnel was effectively controlled and that the air quality was sufficiently improved.

Fabrication of a Plate-Type Porous Stainless Steel 316L Powder Filter with Different Pore Structures without Use of a Binder

Generally, when fabricating porous filters using metal powder, about 1 to 2 wt% of a binder is added to increase the formability of the metal powder. If the binder is not completely removed through a debinding and sintering process, however it can cause defects such as discoloration and the generation of fine particles. In this study, a study was conducted to fabricate a plate-type porous stainless steel powder filter with a different pore structure without the use of a biner. First, the metal powder is charged into a ceramic mold to form a plate-shaped powder filter, and then covered with a ceramic top plate. In order to observe the pore properties according to the pressure, the unpressurized specimen and the specimen pressurized with a pressure of 30 MPa were then sintered at 1050℃ for one hour in a high vacuum atmosphere furnace. The microstructure of the sintered plate-shaped powder filter was observed through an optical microscope and in order to analyze its pore properties as a filter, gas permeability and porosity were measured using a capillary flow porometer and Archimedes’ law.

Discrete Element Modeling of the Breakage of Single Polyhedral Particles in the Rotary Offset Crusher

Innovation in comminution is expected to continue unabated to address the inefficiencies that are inherent in comminution circuits. The rotary offset crusher (ROC) is a new comminution device with a promising performance potential in terms of throughput due to the enhanced speed of transportation induced by the centrifugal force of the discs. However, the processes driving the comminution of particles trapped in the conical space between the two discs of the crusher are not fully understood. To gain a better insight into the comminution process in this device, discrete element modeling (DEM) simulations were conducted to study the breakage of a single particle for the crusher operated under two different dynamic conditions, i.e., (1) a stationary top disc and (2) both discs rotating at the same speed. For both scenarios, the speed of the discs was varied between 550 and 2350 rpm. Experimental testwork was also conducted with the laboratory prototype to generate the data that were used to calibrate the breakage parameters of the Ab × t10 breakage model. Simulations were performed using polyhedral UG2 ore particles that were generated with the in-built particle generator in the DEM simulator. The simulated ROC, which is operated with both discs rotating, outperformed the ROC with a stationary top disc in terms of the specific input energy and throughput. The crusher with a stationary top disc is characterized by high shear forces (suggesting a higher wear rate), specific input energies greater than 1 kWh/t, and low throughputs (<50 kg/h). The ROC operated with a stationary disc is not recommended for hard rock applications due to expected excessive wear of crushing surfaces and higher energy consumption. The freewheeling discs are recommended, but there is scope to optimize the crusher performance in terms of the power draw, size reduction, and throughput by manipulating the difference between the speeds of the discs. There is also scope to optimize the crusher performance when it is simulated with many particles. Once the full performance potential of the ROC is established, it will then be important to benchmark it against the existing crushers in the minerals industry as well as other industries where crushers are used.

Regulation of particle generation processes in a pyroelectric accelerator using geometry

The generation of electrons and X-rays using a pyroelectric accelerator is highly appealing from a practical point of view due to the potential for compact and energy-efficient devices. This study focuses on investigating the influence of accelerator geometry, particularly the position and area of the target. We have determined that a smaller target area enhances X-ray intensity and monoenergetic electron flux, while the balance between positive and negative polarity exhibits weak dependence on geometry. Altering the position of the target-collimator enables regulation of the energy of the collimated electron flow. The focal spot of the electron flow in a pyroelectric accelerator exhibits a complex longitudinal structure, as demonstrated by both experimentation and computer modelling. Furthermore, increasing the distance between the crystal and the target enhances the stability of the pyroelectric accelerator. Consequently, the combined effect of target area and its position relative to the crystal significantly influences the observed particle flux, and we propose approaches for their regulation in practical devices.

Integrating phase change materials and spontaneous emulsification: In-situ particle formation at oil–water interfaces

The properties of interfaces between two immiscible fluids, as engineered by interfacial materials, are crucial in various processes, including printing, coating, and multiphase flow in porous media. Interfacial materials, such as surface-active molecules and particles can be adsorbed from the bulk fluid phases to the interface or formed in-situ at the interface. In this study, we develop a methodology to form stiff silica-based particles in situ at the oil–water interface through coupling of phase change materials and spontaneous emulsification. This process is demonstrated by introducing a heptane micellar solution that spontaneously generates a microemulsion phase when in contact with an aqueous phase. Micron-sized droplets, consisting of an aqueous silicate precursor mixture, undergo a sol–gel reaction, leading to the generation of colloidal-sized particles. SEM micrographs and confocal images of dried samples, taken from the aqueous-heptane interface, reveal the formation of particles post-gelation. The in-situ formation of stiff particles can be characterized through the dynamics of evaporation, where a significant reduction in the heptane evaporation rate is observed. This particle generation method, utilizing phase change materials and emulsion templates, is spontaneous, energy-efficient, and enables particle formation at the interface at a predetermined time. Our findings offer valuable insights for the fabrication of interfacial materials with tailored properties and controlled timing.

Characteristics of tire-road wear particles (TRWPs) and road pavement wear particles (RPWPs) generated through a novel tire abrasion simulator based on real road pavement conditions

Microparticles such as tire-road wear particles (TRWPs) and road pavement wear particles (RPWPs) are generated by the friction between tire tread and road surface. TRWPs and RPWPs on roads are dispersed through traffic and transferred to rivers and seas via runoff to accumulate in sediments. However, research on the generation of both TRWP and RPWP has rarely been conducted. In this study, the generation of both TRWP and RPWP was investigated using a novel tire abrasion simulator equipped with paved road and bus tire, and their contributions to the generation of microparticles were examined. Two types of model paved roads, asphalt and concrete pavements (AP and CP, respectively), were applied. TRWPs generated from the simulator exhibited morphologies very similar to those on real roads. The abrasion rate for the CP was 2.8 times higher than that for the AP. The wear particle size distributions peaked at the size ranges of 63–106 μm and 212–500 μm for the AP and CP, respectively. Totals of 84 wt% and 89 wt% of the wear particles were distributed in size ranges of 38–212 μm for the AP and 106–1000 μm for the CP. The tire wear particle (TWP) contents in the total wear particles of 38–500 μm were 21.7 wt% and 30.0 wt% for the AP and CP, respectively, and decreased as the particle size decreased. The weight of RPWP was higher than that of TWP in TRWP. Contributions from road pavement to the generation of wear particles of 38–500 μm were 3.6 and 2.3 times higher than those from tire tread for the AP and CP, respectively, and the contribution increased as the wear particle size decreased.

Synthesis of nano-calcium carbonate from waste cement and techno-economic and environmental evaluation

Mineral carbonation stands out not only as an effective method for reducing CO2 emissions but also as a strategic approach to upcycling industrial waste. This study introduces a novel procedure for generating high-purity nano-calcium carbonate (nCaCO3) from waste cement powder, deploying hydrochloric acid (HCl), and sodium hydroxide (NaOH), both obtained through the electrolysis of sodium chloride (NaCl). Our approach, aimed at both environmental preservation and techno-economic feasibility, encompasses optimizing calcium extraction conditions through rigorous analysis of variables such as HCl concentration, solid-to-liquid ratio, and reaction temperature, subsequently proposing a rate law for the extraction process. Furthermore, the method emphasizes the production of high-purity CaCO3 by meticulously removing metallic impurities from the extracted solution with 1.0 M NaOH, culminating in pure calcium hydroxide and the generation of nCaCO3 particles with superior purity (>99 %) and a uniform particle size (80–140 nm). An exhaustive environmental and economic assessment indicates that our process, while consuming varying energy levels based on operational potentials, anticipates a significant reduction in CO2 emissions by 46.1 %, alongside a competitive production cost (335 USD/ton of nCaCO3), thereby demonstrating substantial advantages over traditional methods in terms of sustainability, efficiency, and cost-effectiveness.

Optimization and validation of a virus-like particle pseudotyped virus neutralization assay for SARS-CoV-2.

Spike-protein-based pseudotyped viruses were used to evaluate vaccines during the COVID-19 pandemic. However, they cannot be used to evaluate the envelope (E), membrane (M), and nucleocapsid (N) proteins. The first generation of virus-like particle (VLP) pseudotyped viruses contains these four structural proteins, but their titers for wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are relatively low, even lower for the omicron variant, rendering them unsuitable for neutralizing antibody detection. By optimizing the spike glycoprotein signal peptide, substituting the complexed M and E proteins with SARS-COV-1, optimizing the N protein with specific mutations (P199L, S202R, and R203M), and truncating the packaging signal, PS9, we increased the titer of the wild-type VLP pseudotyped virus over 100-fold, and successfully packaged the omicron VLP pseudotyped virus. The SARS-CoV-2 VLP pseudotyped viruses maintained stable titers, even through 10 freeze-thaw cycles. The key neutralization assay parameters were optimized, including cell type, cell number, and viral inoculum. The assay demonstrated minimal variation in both intra- and interassay results, at 11.5% and 11.1%, respectively. The correlation between the VLP pseudotyped virus and the authentic virus was strong (r=0.9). Suitable for high-throughput detection of various mutant strains in clinical serum. In summary, we have developed a reliable neutralization assay for SARS-CoV-2 based on VLP pseudotyped virus.

Effects of inorganic sodium on the soot generation of coal particle: Insights with PLIF and DFT calculation

Inorganic sodium in low rank coal exerts significant influence on the soot generation in the early stage of combustion. The effect of inorganic sodium on the PAHs, soot formation and OH generation of coal particle was investigated on a concentrating light heating platform using Planar Laser Induced Fluorescence (PLIF) of OH radicals and PAHs. The generation characteristics of PAHs during coal particles pyrolysis with the temperature of 500 °C and 800 °C were also investigated. Raw coal, acid-washed (AW) coal and AW impregnated with different mass ratio of NaCl (1 %, 3 % and 5 % NaCl-loaded) were studied. Theoretical calculations using density functional theory was performed to explore the effect of sodium on the conversion of small molecule to macromolecular substances during early coal combustion. The results showed that the NaCl addition inhibited the OH radical and soot generation in the early stage of coal combustion, as demonstrated by the reduced OH intensity, and decreased soot intensity by observing the flame luminosity for the NaCl-loaded coals, compared with AW coal. Simultaneously, the PAHs generation was significantly reduced for NaCl-loaded coals, both at the early stage of coal combustion and under pyrolysis conditions, compared with AW coal. The quantum chemistry calculation revealed that the formed C-Na structure enhanced coal structural stability, making the chemical bonds less prone to cleavage, thereby inhibiting the volatile and PAHs release during the early stage of coal combustion. On the other hand, the released Na+ can catalyze the addition reactions of small ring PAHs (naphthalene, naphthalene derivatives) to larger ring PAHs (phenanthrene, pyrene), which would promote the PAHs and soot generation in homogeneous reactions, explaining the highest PAHs with 3-to-5 rings for 5 % NaCl-loaded coal among NaCl-loaded coals. The above two kings of reaction pathways were related to soot formation, but considering the results of reduced soot yield after NaCl addition, the former dominated. Furthermore, the results from the two pathways also illustrated that the Na inhibit the OH formation, which was corresponding to the decreased OH intensity for NaCl-loaded coals, as detected by OH-PLIF, and thus was detrimental to soot consumption. Therefore, the presence of Na in the early stage of combustion inhibited the release of volatiles and PAHs, which was the main reason for the decreased soot generation amount of NaCl-loaded coal.

Achieving near-zero particle generation by simplicity of design—A compliant-mechanism-based gripper for clean-room environments

Lab Automation facilitates high-throughput processes and improves reproducibility and efficiency while removing human action, primary source of contaminating particles. Handling poses a risk of contamination due to close contact with the objects. We propose a novel gripper (CrocoGrip) relying on compliant mechanisms to reduce the amount of contaminating particles generated by the gripper rather than preventing their emission, the latter being the common approach in current grippers. Our novel gripper is actuated by linear solenoids and purely relies on deformation for its motion. As a result, abrasive behavior and, therefore, the generation of particles is reduced without the need for additional sealing. We experimentally proved that only particles smaller than 3.0µm are emitted by the gripper, with a large proportion of the particles being generated by the actuation. The CrocoGrip fulfills the demands of ISO14644 class 5. The gripping relies on the deformation energy of the compliant mechanism, making the gripping energy-efficient and safe. The maximum gripping force achieved by the CrocoGrip was 5.5N. Because the force transmitted to the handling object depends on the design of the gripping jaws, which are interchangeable, the force can be reduced for more sensible handling objects. Using three different sets of jaws, CrocoGrip was able to handle a microplate in SBS-standard, a 50mL Falcon tube, and a Ø60mm Petri dish using a robotic arm. Due to the monolithic design of the CrocoGrip and, as a result, the need for few components, we achieve a simplicity of design, making cleaning, sterilization and maintenance easy, even for nonexperts. The CrocoGrip exploits the advantages of compliant mechanisms, especially for applications requiring clean-room environments. This approach of compliant-mechanism-based grippers enables an increase in the cleanliness of handling processes without an increase in system complexity of the gripper to facilitate the lab automation of highly sensible processes, such as in tissue engineering.

In vivo rescue of arboviruses directly from subgenomic DNA fragments

ABSTRACT Reverse genetic systems are mainly used to rescue recombinant viral strains in cell culture. These tools have also been used to generate, by inoculating infectious clones, viral strains directly in living animals. We previously developed the “Infectious Subgenomic Amplicons” (ISA) method, which enables the rescue of single-stranded positive sense RNA viruses in vitro by transfecting overlapping subgenomic DNA fragments. Here, we provide proof-of-concept for direct in vivo generation of infectious particles following the inoculation of subgenomic amplicons. First, we rescued a strain of tick-borne encephalitis virus in mice to transpose the ISA method in vivo. Subgenomic DNA fragments were amplified using a 3-fragment reverse genetics system and inoculated intramuscularly. Almost all animals were infected when quantities of DNA inoculated were at least 20 µg. We then optimized our procedure in order to increase the animal infection rate. This was achieved by adding an electroporation step and/or using a simplified 2- fragment reverse genetics system. Under optimal conditions, a large majority of animals were infected with doses of 20 ng of DNA. Finally, we demonstrated the versatility of this method by applying it to Japanese encephalitis and Chikungunya viruses. This method provides an efficient strategy for in vivo rescue of arboviruses. Furthermore, in the context of the development of DNA-launched live attenuated vaccines, this new approach may facilitate the generation of attenuated strains in vivo. It also enables to deliver a substance free of any vector DNA, which seems to be an important criterion for the development of human vaccines.

Statistical analysis and environmental impact of pre-existing particle growth events in a Northern Chinese coastal megacity: A 725-day study in 2010–2018

Pre-existing particles usually constitute the major fraction of atmospheric particles, except during some episodes in the presence of strong emissions and/or secondary generation of fresh particles. Previous case studies have investigated the growth of pre-existing particles and their potential environmental and climate impacts. However, there is limited knowledge about the statistical characteristics of these growth events and related effects. In this study, we examine pre-existing particle growth events using a large dataset (725 days from 2010 to 2018) collected at a coastal megacity in northern China. The occurrence frequency of pre-existing particle growth events was 12.4 % (90 out of 725 days). When these events were related to measured criteria air pollutants, no significant differences were found in PM2.5, SO2, NO2 and NO2 + O3 concentrations between periods with and without pre-existing particle growth events. These 90-day events can be further classified into two categories, i.e., Category 1, with 68 % of events representing the growth of pre-existing particles alone, and Category 2, with 32 % of events representing the simultaneous growth of pre-existing and newly formed particles. In Category 2, the growth rates of pre-existing particles and newly formed particles were close in 21 % of the cases, while pre-existing particles exhibited significantly larger growth rates in 69 % of the cases. Conversely, in 10 % of the cases, the growth rates of newly formed particles were larger. The different growth rate mechanisms were discussed in terms of the volatility of atmospheric condensation vapors. In addition, we present case studies on the impact of pre-existing particle growth on cloud condensation nuclei simultaneously measured, specifically considering the chemistry of condensation vapors and pre-existing particles.

High performance Cu sintering joint for power devices enabled by in-situ generation of Cu particles with multi-level hierarchical structures

Copper (Cu) particle sintering is widely regarded as one of the most ideal interconnect technologies for wide band gap semiconductors owing to its potential for low-temperature curing while withstanding a higher working temperature. Nevertheless, the strict requirements for sintering conditions and high costs limit the widespread application of Cu sintering technology. In this paper, a simple vehicle was introduced into Cu paste formulation to achieve an effective sinter bonding even using commercially available sub-micron or even micrometer Cu particles (C-Cu particles) with the in-situ generation of composite Cu particles. This innovative vehicle comprises Cu salt, a combination of capping agents and reducing agents. The addition of the hybrid capping agent binds Cu atoms to the surface of the C-Cu particles and allows the generated Cu particles (G-Cu particles) produced from the vehicle to grow on their surface, resulting in the in-situ generation of composite Cu particles. Based on the in-situ generated composite Cu particles, sintering experiments were conducted at designated temperatures (200 °C, 225 °C, 250 °C) for various durations (3 min, 5 min, 10 min) in a N2 atmosphere under different pressures (10 MPa, 15 MPa, 20 MPa). A reliable Cu sintered joint with a high shear strength of 41.3 MPa can be achieved at a low temperature (200 °C) using 500 nm C-Cu particles. Moreover, the joints sintered with large size (>3 μm) particles at 250 °C could also reach 43.3 MPa. The in-situ generated composite Cu particles accomplish the transformation of low-energy interfaces of C-Cu/C-Cu to high-energy interfaces of G-Cu/G-Cu, which in turn facilitates low-temperature sintered connection of C-Cu particles and reliable sintered joints formed of large size C-Cu particles. These findings improve the feasibility of Cu sinter bonding in practical applications.

Investigation of lubricant viscosity and third-particle contribution to contact behavior in dry and lubricated three-body contact conditions

The generation of third particles and change in viscosity lead to the gradual degradation of the performance of the machine interface. The generation of third particles may come from wear debris or environmental particles, which form a three-body contact system at the contact interface. The viscosity of the lubricant will also change with the long-term operation of the components. This paper uses a three-body lubrication model to study the influence and interaction of lubricant viscosity change and the presence of third particles on the contact characteristics, including the real contact area, the particle contact area ratio, the solid load percentage, the film thickness, and the evolution of the lubrication regime. The results show that when the interface is in a three-body mixed lubrication regime, the dimensionless total real contact area increases with the increase in particle size and density at the same lubricant viscosity, while the trend is the opposite in dry contact and boundary lubrication interfaces. When viscosity decreases, a three-body contact interface is more prone to entering boundary lubrication than a two-body contact interface, resulting in surface damage. Regardless of surface roughness, particle size, and dry or lubricated contact conditions, the turning point of the contact area (TPCA) phenomenon is usually when the ratio of particle size to surface roughness is 0.8–1.3. Under the same ratio of particle size to surface roughness, the critical load of the TPCA phenomenon increases with the increase in third-particle size and surface roughness, but decreases with the increase in lubricant viscosity and particle density.

Efficient CO Oxidative Coupling to Dimethyl Oxalate over the Pd/Al2O3 Nanocatalyst with the Assistance of Co Doping

AbstractCO oxidative coupling to dimethyl oxalate (DMO) is an important approach for the product of ethylene glycol and CO elimination. In this work, the Co doped Pd/Al2O3 nanocatalyst was highly effective for CO oxidative coupling and enhanced remarkably CO conversion and the formation of DMO. The maximum DMO STY reached 1082 g L−1 h−1 over the Pd/Al2O3@1/20Co catalyst at 130 °C for 2 h under the space velocity of 3000 h−1, which is two times higher than that over the Pd/Al2O3 catalyst. The Co modification and its influence on the structure of the Pd/Al2O3 catalyst were also studied systematically by XRD, TEM, CO‐TPD, N2 physical adsorption and XPS techniques. An appropriate Co doing was confirmed to promote distinctly the generation of smaller Pd particles and the adjustment of the adsorption or activation of CO over the catalyst. A positive interaction between Pd nanoparticles and the modulated support with Co doping was demonstrated and favored the enhanced activity of the catalyst for the reaction.

Improvement in the Accuracy and Efficiency of Smoothed Particle Hydrodynamics: Point Generation and Adaptive Particle Refinement/Coarsening Algorithms

Improvement in the Accuracy and Efficiency of Smoothed Particle Hydrodynamics: Point Generation and Adaptive Particle Refinement/Coarsening Algorithms

Particle traps constructed on the insulator of conductive slip rings for surface flashover mitigation under particle adhesion

The generation of abrasive particles is an unavoidable consequence of sliding electrical contact wear in conductive slip rings (SRs). The adhesion of abrasive particles to the insulators may lead to a decrease in flashover voltage, posing a risk to satellite power transmission. In this paper, the effect of abrasive particles on flashover is first studied. Surface abrasive particles can distort the surface electric field of the dielectric, absorb scattered electrons, and then re-emit them, thereby accelerating the development and formation of secondary electron avalanches. Flashover test results indicate that surface abrasive particles lead to a significant reduction in flashover voltage. To mitigate the impact of particle adhesion on flashover, a method of constructing particle traps on the surface of insulators is proposed. The location and structural parameters of the particle trap are further optimized and determined. The flashover test results using planar dielectric samples and SR insulator samples both demonstrate that the optimized particle trap can significantly improve the flashover voltage. The dielectric maintains high electrical strength even when particles are trapped in particle traps. The physical details of the impact of particles on flashover and the effect of particle traps are analyzed utilizing an electron movement simulation, corroborating the experiment from a microscopic aspect.

Catalytic styrene combustion over Pt/ZSM-5 Catalysts: Elucidating the deactivation mechanism induced by surface acid sites

Catalytic oxidation plays a pivotal role in styrene elimination, yet the development of highly active and robust catalysts remains a challenge. This work aims to elucidate the mechanisms underlying styrene oxidation and catalyst deactivation over the Pt@ZSM-5 catalyst. The Pt@ZSM-5 catalyst with low Si/Al ratio and high surface acidity leads to generation of small Pt particle, the initial activity of the catalyst varies in a volcanic curve with the size of Pt particles. Notably, the Pt@ZSM-5–40 catalyst with Pt particle size of 3.3 nm exhibits the highest reaction rate of 1.6 µmol gPt−1 s−1 at 100 °C. However, the Pt@ZSM-5 catalysts undergo significant deactivation at their T80 (the temperature styrene conversion of 80 %). Through comprehensive characterizations and detailed mechanistic studies, it has been observed that intermediates from styrene oxidation accumulate heavily on the catalyst, especially for the Pt@ZSM-5 catalyst with high acidity. Improving the reaction temperature could inhibit the deactivation which is dependent on the surface acidity of Pt@ZSM-5 catalyst. For instance, the Pt@ZSM-5–800 and Pt@ZSM-5–1200 catalysts remains high activity when reaction is operated at T99+30, whereas a substantially higher reaction temperature (T99+80) is required for both Pt@ZSM-5–18 and Pt@ZSM-5–40 catalysts to counteract deactivation. Our primary results provide insights to develop effective and robust catalyst for styrene oxidation.

Augmented dataset for multidimensional ballast segmentation and evaluation

Ballast plays an important role as a railway track supporting structure against repeated loading. Ballast degradation results in poor drainage, lateral instability, excessive settlement, service interruptions, and safety concerns. Therefore, utilizing efficient methods for evaluating ballast fouling is important to ensure safe railroad operations. Emerging computer vision approaches have been effectively incorporated into the ballast inspection processes to enhance their accuracy and robustness. Owing to the inherent data-driven nature of deep learning approaches, the efficacy of the developed model heavily depends on the quality of the training dataset, revealing an urgent need for a comprehensive and high-quality annotated ballast aggregate dataset. In this study, a multidimensional ballast aggregate dataset has been established which contains realistic data collected from field and laboratory setups, augmented by data produced by a synthetic ballast particle generator. In the dataset, the 2D data comprised ballast images with 2D annotations (masks) for localizing the particles in the images. The 3D data comprises height maps, point clouds, and 3D annotations for particle localization. The collected data included various environmental lighting levels and fouling conditions to ensure adequate coverage and diversity in the training dataset. A 2D ballast particle segmentation model previously developed by the authors was trained using an augmented dataset and demonstrated reliable and accurate results in field ballast inspections. The proposed dataset will be utilized in future studies, including 3D ballast particle segmentation and shape completion, to aid in the inspection and investigative methods for effective ballast maintenance.