Separate Chambers Research Articles

Enabling Efficient Oxygen Evolution via Anchoring Carbon-Layer-Confined RuOx on a Well-Matched Substrate.

Oxygen evolution reaction (OER) is a multistep proton-coupled four-electron process with sluggish kinetics, which seriously limits the hydrogen production efficiency, thus it is of great importance to develop an efficient and stable OER catalyst. In this study, a two-step differential pyrolysis strategy is employed to design a three-dimensional porous microstructured material consisting of RuOx nanoparticles coated by a thin-layer carbon, where the active particles were isolated in separate chambers and the RuOx nanoparticles mainly existed in the form of a heterogeneous interface between RuO2 and partial metallic Ru. The preparation parameters of the catalysts are optimized via combining transient and steady-state polarization properties, and the target catalyst Cat-500-1.5t shows the best OER catalytic performance after ca. 60 h of a chronopotentiometry test in an acidic medium with a much smaller performance change than other samples. The unique design of adopting a carbon layer to form separate reaction chambers largely mitigates the excessive oxidation loss of the active components under strong oxidation potential. The suitability of the catalyst with the loaded substrate and test media is explored, and in an acidic medium, the carbon paper is much better than the titanium fiber, while in an alkaline medium, the titanium fiber is obviously superior to the carbon paper. On both carbon paper and titanium fiber, the performance in an alkaline medium outperforms that in an acidic medium, and the possible reasons for the performance difference are analyzed. Herein, to obtain the actual electrocatalytic performance, the optimal design of the catalyst structure and matching suitable conductive substrate in a specific medium are quite necessary, which provides a feasible strategy for the acquisition of efficient and stable electrocatalysts and the desirable presentation of performance.

Microfluidic colorimetric biosensor for rapid and sensitive detection of Shewanella oneidensis MR‑1

Extracellular respiratory bacteria (ERB) assume a significant role in biological and environmental remediation, so the rapid detection of ERB is essential to monitor its biological repair process. This study developed a microfluidic colorimetric biosensor for rapid and sensitive detection of ERB model strain Shewanella oneidensis MR-1. In the process of separation and enrichment of bacteria based on immune magnetic nanoparticles (MNPs), the biological signal is significantly amplified by the excellent peroxidase activity of flower-like CoOOH (FL-CoOOH). Firstly, immune MNPs, samples and immune FL-CoOOH were mixed and incubated within the microfluidic chip’s channel. Magnetic capture in the separation chamber yielded MNP-bacteria-CoOOH complex. Then, 3, 3′, 5, 5′-tetramethylbenzidine (TMB) substrate was added to make the FL-CoOOH nanozyme catalyze the formation of yellow product. Finally, the target bacteria in the microplate were quantitatively detected. Based on the excellent simulated enzyme activity and stability of FL-CoOOH, the detection can be completed within 45 min after the introduction of the microfluidic chip. The detection was 5×101∼5×106 CFU/mL. Compared with the previously reported colorimetric sensors for MR-1, the sensitivity was increased by 99.54 % to 23 CFU/mL. This study uniquely integrates optical sensors and microfluidic technology for rapid ERB detection with enhanced portability. The design of biosensor can facilitate further investigations into extracellular respiration mechanisms and rapid ecological environment restoration applications.

Flow-electrode capacitive separation of organic acid products and recovery of alkali cations after acidic CO2 electrolysis

Acidic CO2 electrolysis, enhanced by the introduction of alkali cations, presents a strategic approach for improving carbon efficiency compared to processes conducted in neutral and alkaline environments. However, a significant challenge arises from the dissolution of both organic acids and alkali cations in a strongly acidic feed stream, resulting in a considerable energy penalty for downstream separation. In this study, we investigate the feasibility of using flow-electrode capacitive deionization (FCDI) technology to separate organic acids and recover alkali cations from a strongly acidic feed stream (pH ~ 1). We show that organic acids, such as formic acid and acetic acid, are retained in molecular form in the separation chamber, achieving a rejection rate of over 90% under all conditions. Alkali cations, such as K+ and Cs+, migrate to the cathode chamber in ionic form, with their removal and recovery significantly influenced by their concentration and the pH of the feed stream, but responding differently to the types and concentrations of organic acids. The energy consumption for the removal and recovery of K+ is 4 to 8 times higher than for Cs+, and the charge efficiency is significantly influenced by the types of organic acid products and alkali cations. We conduct a series of electrochemical measurements and analyze the impedance spectroscopy, identifying that hindered mass transfer governed the electrode process. Our findings underscore the potential of FCDI as an advanced downstream separation technology for acidic electrocatalysis processes.

Optimizing equine sperm quality: an alternative to single layer centrifugation for sperm isolation.

In vitro semen purification techniques have been developed that seek to mimic the in vivo selection process in order to generate the highest possible chance of oocyte fertilization following artificial insemination. Numerous methods have been developed to isolate functional spermatozoa for artificial insemination, yet only one method, single-layer centrifugation using commercial preparations like EquiPure, has been widely employed. In this study, we have introduced a novel approach for isolating spermatozoa and compared their quality to those isolated using EquiPure. The AI port system (Memphasys, Ltd. in Sydney, Australia) features a disposable cartridge with an inoculation chamber for depositing extended semen and a harvest chamber for extracting isolated spermatozoa. These chambers are separated by a 5 µm polyethylene terephthalate (PETE) membrane, allowing highly motile spermatozoa to migrate from the inoculation chamber to the harvest chamber over a 20-minute period. This migration effectively leaves behind seminal plasma and other cell types, such as leukocytes. Comparative analyses between spermatozoa isolated with the AI port and EquiPure demonstrated that, across all measured sperm parameters, including yield, vitality, motility, morphology, DNA fragmentation, and mitochondrial superoxide generation, the AI port-isolated cells exhibited comparable or superior performance, particularly in terms of DNA fragmentation. In summary, the AI port system demonstrates the potential to efficiently isolate high-quality spermatozoa, possibly offering a cost-effective and user-friendly alternative that may enhance the success rates of artificial insemination in breeding programs. This study aimed to create a new method for refining stallion semen to increase the likelihood of a successful pregnancy through artificial insemination. While there are existing techniques for isolating high-quality sperm, the most common involves a complicated process using a centrifuge, which spins the semen to separate it. This research introduces a new approach called the AI port system that uses a disposable cartridge with two separate chambers for putting in semen and getting out isolated sperm. A membrane between the chambers acts like a filter, letting highly motile sperm swim across, leaving behind unwanted substances like bacteria and blood cells. Compared to the centrifugation method, the AI port system effectively produces sperm with comparable or better quality in various aspects, including vitality, movement, shape, DNA integrity, and energy production. In summary, the AI port system is an easy-to-use alternative with the potential to improve the success of artificial insemination in horse breeding programs.

Experimental study on decarburization of fine fly ash by electric separation

ABSTRACT The effect of rotary triboelectric separation parameters on decarburization of fly ash was systematically studied to prove that the technology was an effective means to purify fly ash. The results showed that obvious mismatch of carbon particles occurs when separation voltage was greater than 25 kV, while mismatch of other mineral particles was generated when separation voltage was greater than 30kV; The decarburization effect of fly ash could be significantly reduced due to the decrease of particle surface charge density when the feed frequency was greater than 20 hz. The feed was also affected by the speed and direction of the particle feed, the closer to the middle of the feed port, the higher the probability of the particle being effectively separated; when rotation speed of the friction wheel exceeded 4000 r/min, the particle mismatch in the separation chamber becomes more and more obvious. In addition, the speed of the friction wheel also affected flow field in separation chamber, which may have an adverse effect on separation effect; Co-flow velocity affected retention time of particles in the separation chamber. 6 m/s is the best co-flow velocity for fly ash decarburization. In this case, the flow field generated by the co-flow is uniform to ensure stable transport of particles.

Study on the separation performance of a three-product hydrocyclone with overflow reseparation

This manuscript proposes a three-product hydrocyclone with overflow reseparation to reduce the particle misplacement in overflow, which achieves secondary separation by utilizing the after-energy of internal swirling flow. Numerical simulations and physical tests were applied to investigate the separation performance. The simulation results revealed that the coarser particles entrapped were effectively recovered by sideflow, the recovery of 20 μm particles in the overflow decreased by 16.71 % ∼ 23.09 % with significant fineness improvement compared with conventional hydrocyclone. The intensity of the internal centrifugal field decreased with the overflow separation chamber expanded, which resulted in an increased probability of particle misplacement during overflow. The test results revealed that the particle content of more than 20 μm in overflow was reduced by 2.44 % compared with conventional hydrocyclone, reducing the overflow separation chamber increased the sideflow ratio and solid phase yield, increased the difference in fineness between sideflow and overflow, and improved the narrow-grain separation performance.

Analysis of the effect of geometric and flow parameters on the separation efficiency of virtual impact separators: Optimization based on response surface methodology

Respiratory dust is the primary factor triggering pneumoconiosis. Accurately separating respiratory dust from total dust according to specific criteria are key aspects of respiratory dust monitoring and prevention technology. In this study, we numerically solve the gas-solid two-phase flow within a virtual impactor by coupling computational fluid dynamics (CFD) with the discrete element method (DEM). Here, we explored the air velocity and dust separation efficiency of each component of the virtual impactor to determine optimal structural scale parameters. Accurate 3D printing technology was employed to materialize the three-dimensional structure of the virtual impactor. The separation efficiency of the virtual impactor was evaluated and verified through simulated duct experiments. The results indicate that the weak flow ratio has the most significant effect on separation efficiency, followed by the effect of the ratio of separation chamber diameter to nozzle width (S/W), the ratio of the weak flow outlet size to nozzle width (D/W) aving the smallest degree of influence. When S/W is 1.8, D/W is 1.333, and the weak flow ratio is 0.1, the separation efficiency curves show optimal performance, as confirmed by experimental verification. The experimental verification matched the simulated separation efficiency data within a deviation range of 1.10–11.4 %.

A New Approach to Vertical Plant Cultivation Maximises Crop Efficiency

This publication presents an innovative tower cultivation device designed to significantly increase vertical farming’s efficiency. The device divides the cultivation system into separate chambers. One division corresponds to the different growth phases of the plants, while another reflects the daily variation in conditions. Each chamber presents slightly different conditions and cultivation patterns from the others. For the early stages, crops are grown horizontally in trays; once they mature, they are transplanted into mobile cultivation towers. The closed circulation of ventilation and irrigation reduces water consumption by up to 95%. A unique separate day–night division optimises light, temperature, and humidity conditions, mimicking natural growth patterns. This approach not only saves water and energy but also improves cultivation in a three-dimensional space. The presented solution focuses on the often-overlooked aspects of cultivating in vertical farms and makes this method of growing much more cost-effective and feasible to implement on a large scale. Our comparative analysis with other vertical farming solutions is based on publicly available data and provides valuable insights, while acknowledging the potential limitations at play.

An Empirical Study on the Upcycling of Glass Bottles into Hydrocyclone Separators

Cyclones are pivotal in mechanical process engineering and crucial in the complex field of separation technology. Their robustness and compact spatial requirements render them universally applicable and versatile across various industrial domains. Depending on the utilized fluid and field of application, both gas-based cyclones and hydrocyclones (HCs) are well established. Regarding HC design, enduring elongated flat cones have seen minimal alterations in shape and structure since their introduction over more than a hundred years ago. Experimental investigations regarding unconventional cone designs within scientific studies remain the exception. Therefore, this study focuses on alternative geometric configurations of the separation chambers and highlights their impact on separation and energy efficiency. To achieve this objective, different geometric shapes are investigated and retrofitted into HCs. The geometric foundation is derived from upcycled glass bottles. The repurposed bottles with a volume of 750 mL are used in conjunction with an inlet part, following the established Rietema design. Experimental tests are conducted with dilute phase separation, using 0.1–200 µm test particles in water. Comparisons between a bottle-based HC and a conventional Rietema design were conducted, establishing a benchmark against the standard. The findings revealed a noticeable correlation between separation efficiency and cone geometry. Conical designs demonstrated enhanced separation, particularly at lower volume flows. At the highest volume flow of 75 L min−1, the best performing bottle cyclones showed separation efficiencies of 78.5%, 78.4% and 77.9% and therefore are in a competitive range with 78.0% efficiency, achieved using the commercial Rietema design. Minimal disparities in cut sizes were observed in terms of separation grade efficiency among the models tested. Variations in separation efficiency and fractional efficiency curves indicated nuanced differences in classification efficiency.

Arbuscular Mycorrhizal Fungi Mediate the Acclimation of Rice to Submergence.

Flooding is a critical factor that limits the establishment of a symbiosis between rice and arbuscular mycorrhizal fungi (AMF) in wetland ecosystems. The distribution of carbon resources in roots and the acclimation strategies of rice to flooding stress in the presence of AMF are poorly understood. We conducted a root box experiment, employing nylon sheets or nylon meshes to create separate fungal chambers that either prevented or allowed the roots and any molecules to pass through. We found that the mycorrhizal colonization rate and the expression of genes OsD14L and OsCERK1, which are involved in fungal perception during symbiosis, both increased in mycorrhizal rice roots following intermittent flooding compared to continuous flooding. Furthermore, AMF inoculation affected root morphological traits, facilitating both shallower and deeper soil exploration. Increased submergence intensity led to carbohydrate deprivation in roots, while high mycorrhizal colonization increased soil oxygen consumption and decreased the neutral lipid concentration in roots. However, mycorrhizal inoculation increased the rice photosynthesis rate and facilitated acclimation to submergence by mediating the expression of the genes OsCIPK15 and OsSUB1A to enhance rice shoot elongation and the sugar concentration in roots as a result of reduced competition for carbon between rice and AMF under different flooding conditions.

Оптимизация гидрологических расчетов систем очистки поверхностного и дренажного стока воды

Objective: to develop a method for determining the optimal hydrological characteristics of systems for treating contaminated surface and drainage waters. Methods: the pollutant balance equation was applied. For comparison, the method of the Vodgeo Research Institute was used. The costs of treatment and environmental damage from pollution of watercourses were studied for various water levels of the year and the parameters of treatment facilities. The main parameters chosen are the types of pollutants (suspended substances and petroleum products) and the separation coefficient of the runoff in the separation chambers. Results: a method has been developed for optimization calculations of the hydrological characteristics of surface and drainage water treatment systems, taking into account the likelihood of runoff during high water and floods, the costs of construction and operation of treatment facilities and damage from pollution of watercourses. As an example, optimization calculations were performed for several options for treating melt, rain and drainage runoff. Practical importance: the method of optimization calculations of environmental protection will allow a more reasonable and accurate determination of the required degree of wastewater treatment, productivity and parameters of treatment facilities, and in some cases — to reduce the degree of pollution of watercourses.

Nanoscale thermal imaging of hot electrons by cryogenic terahertz scanning noise microscopy.

Nanoscale thermal imaging and temperature detection are of fundamental importance in diverse scientific and technological realms. Most nanoscale thermometry techniques focus on probing the temperature of lattice or phonons and are insensitive to nonequilibrium electrons, commonly referred to as "hot electrons." While terahertz scanning noise microscopy (SNoiM) has been demonstrated to be powerful in the thermal imaging of hot electrons, prior studies have been limited to room temperature. In this work, we report the development of a cryogenic SNoiM (Cryo-SNoiM) tailored for quantitative hot electron temperature detection at low temperatures. The microscope features a special two-chamber design where the sensitive terahertz detector, housed in a vacuum chamber, is efficiently cooled to ∼5K using a pulse tube cryocooler. In a separate chamber, the atomic force microscope and the sample can be maintained at room temperature under ambient/vacuum conditions or cooled to ∼110K via liquid nitrogen. This unique dual-chamber cooling system design enhances the efficacy of SNoiM measurements at low temperatures. It not only facilitates the pre-selection of tips at room temperature before cooling but also enables the quantitative derivation of local electron temperature without reliance on any adjustable parameters. The performance of Cryo-SNoiM is demonstrated through imaging the distribution of hot electrons in a cold, self-heated narrow metal wire. This instrumental innovation holds great promise for applications in imaging low-temperature hot electron dynamics and nonequilibrium transport phenomena across various material systems.

In Situ Pulsed Hydrogen Implantation in Atom Probe Tomography.

The investigation of hydrogen in atom probe tomography appears as a relevant challenge due to its low mass, high diffusion coefficient, and presence as a residual gas in vacuum chambers, resulting in multiple complications for atom probe studies. Different solutions were proposed in the literature like ex situ charging coupled with cryotransfer or H charging at high temperature in a separate chamber. Nevertheless, these solutions often faced challenges due to the complex control of specimen temperature during hydrogen charging and subsequent analysis. In this paper, we propose an alternative route for in situ H charging in atom probe derived from a method developed in field ion microscopy. By applying negative voltage nanosecond pulse on the specimen in an atom probe chamber under a low pressure of H2, it is demonstrated that a high dose of H can be implanted in the range 2-20 nm beneath the specimen surface. An atom probe chamber was modified to enable direct negative pulse application with controlled gas pressure, pulse repetition rate, and pulse amplitude. Through electrodynamical simulations, we show that the implantation energy falls within the range 100-1,000 eV and a theoretical depth of implantation was predicted and compared to experiments.

Experimental environment for testing the shattered pellet injection of KSTAR

The dual shattered pellet injection (SPI) systems installed at the KSTAR (Korean Superconducting Tokamak Advanced Research) have been operational since 2019 to conduct disruption mitigation studies in support of ITER DMS (Disruption Mitigation System) design activities. The system has the advantage of firing pellets simultaneously from the two identical pellet injectors installed at 180-degree opposite positions on KSTAR. Each injector is capable of fabricating and firing three pellets of different sizes (diameter, length). The characteristics of the initial pellet (geometry, velocity, etc.) can be verified using a microwave cavity (MWC) system and an imaging optical pellet diagnostics (OPD) system.Each SPI system must achieve specific conditions related to pellet fabrication and firing prior to plasma experiments. We realized that we didn't have the sufficient time and conditions to do off-line testing in 2022, so we have developed a suitable solution. First, we have to disconnect the SPI system from the KSTAR vacuum vessel and build a separate test chamber in the injection line. Inside the new test chamber, we have to install the same shatter tube used in the current experiments and equip it with measuring devices to observe the fragmented pellets. We also have to switch the fabrication process of the pellets from manual to semi-automatic using a feedback pressure controller on the barrel pressure. In this paper, we will describe the new experimental environment for independent SPI testing and the future plan.

First Report of Powdery Mildew caused by Erysiphe astragali on Sphaerophysa salsula.

Sphaerophysa salsula (Pall.) DC., also known as Yang Liao Pao, belongs to the Leguminosae family and is the only existing species in the Sphaerophysa genus. S. salsula is tolerance to cold, high salt, and alkaline soil, it is widely cultivated in China as a forage crop, and used as a Chinese folk medicine to treat hypertension (Ma et al., 2002). In 2023, signs and symptoms similar to powdery mildew were found on S. salsula planted in Tumd left (40.515°N, 110.424°E), Baotou City, Inner Mongolia Autonomous Region, China. The white powdery substance covered 90% of the leaf area, and the infected plants showed weak growth and senescence. More than 80% of plants (n=200) had these powdery mildew-like symptoms. Hyphal appressoria are solitary, conidiophores have few branches and septa. Conidia are cylindrical to clavate, 25-32 μm long and 8-15 μm wide (n=30), conidia form single subapical germ tubes, straight to curved-sinuous, with swollen apex or distinctly lobed conidial appressorium. Based on these morphological characteristics, the fungus was tentatively identified as an Erysiphe sp. (Schmidt and Braun 2020). Fungal structures were isolated from diseased leaves, and genomic DNA of the pathogen was extracted using the method described by Zhu et al. (2022). The internal transcribed spacer (ITS) region was amplified by PCR using the primers PMITS1/PMITS2 (Cunnington et al. 2003) and the amplicon sequenced by Invitrogen (Shanghai, China). The powdery mildew strain, named as KMD (GenBank accession no.: PP267067), showed an identity of 100% (645/645bp) with Erysiphe astragali, a powdery mildew reported on Astragalus glycyphyllos in Golestan, Iran (GenBank: OP806834) and identity of 99.6% (643/645bp) with Erysiphe astragali (GenBank: MW142495), a powdery mildew reported on A. scaberrimus in Inner Mongolia, China (Sun et al. 2023). Pathogenicity tests were conducted by brushing the conidia from infected S. salsula leaves onto leaves of four healthy plants, while four control plants were brushed in the same manner. All the treated plants were placed in separate growth chambers maintained at 19°C and 65% humidity, with a 16 h light/8 h dark photoperiod. Nine days after inoculation, the treated plants showed powdery mildew symptoms, while the control plants remained asymptomatic. The same results were obtained for two repeated pathogenicity experiments. The powdery mildew fungus was reisolated and identified as E. astragali based on morphological and molecular analysis, thereby fulfilling Koch's postulates. No report on the occurrence of powdery mildew on S. salsula plants has been found previously. The occurrence of this destructive powdery mildew may adversely affect the cultivation of S. salsula. Identifying the pathogen of powdery mildew will support future efforts to control and manage powdery mildew on S. salsula.

A perfusion host-microbe bioreactor (HMB) system that captures dynamic interactions of secreted metabolites between epithelial cells cocultured with a human gut anaerobe.

The human microbiota impacts a variety of diseases and responses to therapeutics. Due to a lack of robust in vitro models, detailed mechanistic explanations of host-microbiota interactions cannot often be recapitulated. We describe the design and development of a novel, versatile and modular in vitro system that enables indirect coculture of human epithelial cells with anaerobic bacteria for the characterization of host-microbe secreted metabolite interactions. This system was designed to compartmentalize anaerobes and human cells in separate chambers conducive to each organism's requisite cell growth conditions. Using perfusion, fluidic mixing, and automated sample collection, the cells continuously received fresh media, while in contact with their corresponding compartments conditioned supernatant. Supernatants from each chamber were collected in a cell-free time-resolved fashion. The system sustained low oxygen conditions in the anaerobic chamber, while also supporting the growth of a representative anaerobe (Bacteroides thetaiotaomicron) and a human colonic epithelial cell line (Caco-2) in the aerobic chamber. Caco-2 global gene expression changes in response to coculture with B. thetaiotaomicron was characterized using RNA sequencing. Extensive, targeted metabolomics analysis of over 150 central carbon metabolites was performed on the serially collected supernatants. We observed broad metabolite changes in host-microbe coculture, compared to respective mono-culture controls. These effects were dependent both on sampling time and the compartment probed (apical vs. basolateral). Coculturing resulted in the depletion of several important metabolites, including guanine, uridine 5'-monophosphate, asparagine, and thiamine. Additionally, while Caco-2 cells cultured alone predominantly affected the basolateral metabolite milieu, increased abundance of 2,3-dihydroxyisovalerate and thymine on the basolateral side, occurred when the cells were cocultured with B. thetaiotaomicron. Thus, our system can capture the dynamic, competitive and cooperative processes between host cells and gut microbes.

Effect of Warm Temperature Interruption on the Accumulation of Winter Chilling in Kiwifruit (Actinidia chinensis Planch. and A. deliciosa A. Chev.)

Warm temperature exposure during winter has reportedly resulted in the apparent negation of chilling in several fruit species. This study was conducted to investigate the floral and vegetative response of two pistillate kiwifruit cultivars to intermittent warm temperature interruption during chilling accumulation. Dormant 1-year-old canes of Actinidia chinensis ‘AU Golden Dragon’ and Actinidia deliciosa ‘AU Fitzgerald’ were collected in December 2018 and 2019 (334 and 360 chilling units, respectively), shortly after leaf abscission. Canes were cut to 10 nodes after removing the first six basal nodes, placed in jars filled with distilled water, and transferred to respective chilling treatments. Treatments included continuous chilling (CC) (in addition to base chilling) at 1-week (168 chilling units) increments (0–5 weeks) and chilling exposure at the same increments with intermittent warm temperature (WT). For the WT treatments, each week of chilling was followed by 3 days of exposure to warm conditions. Chilling and warm temperature exposure were simulated by 7/4 °C and 25/17.2 °C (day/night) air temperatures, respectively, using separate climate-controlled growth chambers. After treatments, canes were forced in a third chamber at 21.1 to 25.0 °C with light-emitting diode lighting. Vegetative budbreak, floral bud number (from here on defined as floral response), and floral development stage were recorded for each cane at 2-day intervals. For ‘AU Golden Dragon’, WT did not result in any reduced floral response at any of the observed chilling levels. However, lower mean floral response was observed with WT, as compared with CC for ‘AU Fitzgerald’ at 5 weeks of chilling over the 2 years (P = 0.05). WT also lessened the effect of apical dominance with respect to vegetative/floral response to node position for both cultivars. Chilling type had no significant effect on vegetative response in either cultivar. Estimated chilling requirements (CC) in this experiment were similar to those reported previously for these cultivars. Results suggest that A. chinensis cultivars may respond more favorably than A. deliciosa to the erratic winter temperature patterns experienced in the southeastern United States.

T–01M TESTER ADAPTATION FOR WEAR DEBRIS COLLECTIONAND ANALYSIS

The article describes the need to collect and analyse data on stereological features of car tire and brakesystem friction material wear products, as required under new European Union regulations and by the projectto expand the existing T–01M tester with a separation chamber and equipment enabling their capture. Thestructure of the chamber is described and the conditions for measuring the average diameter of particlesemitted by the tested contacts are presented. The basic task of the additional chamber is to separate thesurroundings of the tested friction node from environmental influences and to enable the capture of wearproducts to measure stereological features and analyse their chemical composition. A unidirectional filteredair flow towards the friction node is provided in the separation chamber in order to limit the deposition of wearproducts on the tester components. Mounting the separation chamber does not require any interference in thestructure of the T–01M tester, because it is mounted on a sealed base frame screwed to the station plate. Thechamber is equipped with holders for mounting a replaceable filter at the air inlet and a removable cycloneparticles separator with a container for wear debris collected.

Research on the separation chamber diameter ratio of the multi-stage hydrocyclone to inhibit particle misplacement

The particle radial settling distance is determined by the separation chamber diameter ratio of multistage hydrocyclones, affecting particle circulation flow and particle misplacement. The effect of the separation chamber diameter ratio on the flow field and separation performance is explored using numerical simulations and physical experiments. The findings indicate that a larger separation chamber diameter ratio increases the particle circulation flow ratio and coarse particle circulation flow proportion, intensifying the particle enrichment ratio. However, smaller separation chamber diameter ratios result in higher turbulence intensity and higher enrichment ratio of coarse particles in the primary separation chamber. Both oversize and undersize separation chamber diameter ratios exacerbate misplaced coarse particles. Physical test results indicate that misplaced fine particles and coarse particles diminish and eventually increase with increasing the separation chamber diameter ratio. The + 150 μm particle content in the overflow reaches the minimum value of 0.32 % in the separation chamber diameter ratio of 0.5. In comparison, the –23 μm particle content in the underflow reaches the minimum value of 3.7 % in the separation chamber diameter ratio of 0.6, and the classification efficiency of −74 μm reaches the maximum of 61.85 %. Consequently, both large and small separation chamber diameter ratios will aggravate particle misplacement and deteriorate classification performance by augmenting the coarse particle circulation flow.

Optimization of Parameters for Fluidized Bed-Type Tribo-Electrostatic Separation of End-of-Life Vehicle Waste Polymer Particles by Response Surface Methodology

End-of-life vehicles (ELVs) have resulted in huge quantities of waste vehicle polymers, the reuse of which could be effective in mitigating pollution and creating economic value. Based on the developed fluidized bed-type electrostatic separation equipment, this paper investigated the separation of two groups of commonly used mixed vehicle-use polymer particles, namely, acrylonitrile-butadiene-styrene (ABS)-polyamide (PA)-polypropylene (PP) (black) and polyethylene (PE)-PP (white)-polyvinyl chloride (PVC). First, the force of the particle in an electric field was analyzed, and the kinetic model of the particle in a high-voltage electrostatic field was established. Then, individual factor experiments were conducted on the fluidization time (T), the first-stage electrostatic separation chamber electrode voltage (U 1), the second-stage electrostatic separation chamber right field electrode voltage (U 3) and the second-stage electrostatic separation chamber left field electrode voltage (U 5) to investigate the pattern of separation results affected by each of these factors, individually. Finally, based on response surface methodology (RSM) experiments, the effects of the abovementioned three factors and their interactions on the purity of the separation of the three types of particles in each group were analyzed. The optimum separation parameters for ABS-PA-PP (black) particles in the experiments were determined as follows: T of 385 s, U 1(U 3) of −32 kV and U 5 of −37 kV. The optimum separation parameters for PE-PP (white)-PVC particles were found as follows: T of 398 s, U 1(U 3) of −40 kV and U 5 of −38 kV. The experimental validation of the abovementioned parameters obtained the purities of the three set of ABS-PA-PP (black) types of particles being 95.67%, 91.34% and 99.12%, respectively. The purities of the three set of PE-PP (white)-PVC types of particles being 96.21%, 93.20% and 86.74%.