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The aim of this study is to establish a dynamic model of the filtration ratio. For the problem that the measured value of the filtration ratio is far less than the theoretical value in the actual hydraulic filtering system, the paper aims to find the relationship between the filtration ratio and the parameters of the hydraulic systems, such as the contamination level and the dirt-holding quantity of the filter.

The paper opted for the method of experimental analysis and simulation to determine the relationship between the filtration ratio and the parameters of the hydraulic system, and established a dynamic filtration ratio model.

The paper provides a preliminary model of dynamic filtration ratio, and the model shows that the filtration ratio is exponentially related to the contamination level and the dirt-holding quantity. Different filters have different influence coefficients. The filtering capacity for a certain particle size and the contamination level control of the filter for different hydraulic systems can be judged according to the dynamic balance equation of hydraulic systems.

The paper is useful in the selection of filters and in the precise control of the contamination level of the hydraulic system.

The purpose of this paper is to explore the factors that affect the compactness of the mud filter cake, so as to prepare diaphragm wall slurry with good uniformity, small filtration loss and excellent recycling performance.

In this paper, the thickness, filtration loss and slurry viscosity of the filter cake are used as the characterization methods. The effects of pore depth, slurry specific gravity, intercalated metal ions, bridging polymer and water-soluble polymer on the compactness of the filter cake were studied.

The experimental results showed that the slurry's own pressure (pore depth) and specific gravity have little influence on the compactness of the filter cake and K⁺ can be considered as an auxiliary filtration loss reduction factor. Both the sulfonate copolymer and the potassium polyacrylate particle can significantly reduce the filtration loss of the slurry, which can effectively improve the filter cake compactness. Moreover, the composite application of potassium polyacrylate particles in the sizes of 80–100 and 150–200 meshes can exhibit a better filter cake compaction effect.

It solves the problems of high pulping cost, serious pollution of the environment, poor quality of filter cake formation and large filtration loss during the construction of the diaphragm wall, which improved the construction quality of the diaphragm wall.

The paper aims to deal with the analysis of tribodiagnostic parameters of oil filter device to investigate the possibility to launch a thorough treatment of non-invasive filtration of oil during the full operation of machinery and equipment.

Tribotechnical diagnostic of the oils is based on the observation of the operating oil aging and assesses the rate of change of intensity and the degree of degradation of the oil to change the performance characteristics of the oil and, thus, the capacity of oil for the satisfactory operation of the device. Tribotechnical diagnostic equipment is based on monitoring the wear of its components and assessing the concentration of wear particles in the analyzed oil and intensity of wear.

The monitored values show a stabilization at levels in which the contamination cannot damage machinery and equipment and their individual components. It is shown that with this method, the oil becomes a very important indicator and gives, by using several tribotechnical analysis described in the paper, immediate representation of the internal condition of the tribosystems in the machine. The desired level of purity of the oil system becomes a standard value for the next period of operation, and any deviation of analyzed values can be almost immediately identified.

The paper involves investigation on non-invasive filtration of oil during the full operation of machinery and equipment; non-invasive filtration experimental analysis of used oil after filtration; And experimental effectiveness evaluation of the filtration. Purity of the oil system becomes the target value for the online monitoring.

Cleanrooms are highly controlled enclosed rooms where air quality is monitored and ensured to have less contamination according to standard cleanliness level. Air filters are used to optimize indoor air quality and remove air pollutants. Filter media and filtering system are decided as per requirement. Depth filter media are mostly used in cleanroom filtrations. This paper aims to present a comprehensive review of the evolution of cleanroom filter media. It evaluates the advantages and disadvantages of air filter media. It is also studied which air filters have additional properties such as anti-microbial properties, anti-odour properties and chemical absorbent. Development and innovation of air filters and filtration techniques are necessary to improve the performance via the synergistic effect and it can be a possible avenue of future research.

This paper aims to drive the future of air filter research and development in achieving high-performance filtration with high filtration efficiency, low operational cost and high durability. Air pollutants are classified into three types: suspended particles, volatile organic pollutants and microorganisms. Technologies involved in purification are filtration, water washing purification, electrostatic precipitation and anion technology. They purify the air by running it through a filter medium that traps dust, hair, pet fur and debris. As air passes through the filter media, they function as a sieve, capturing particles. The fibres in the filter medium provide a winding path for airflow. There are different types of air filters such as the high-efficiency particulate air filter, fibreglass air filter and ultra-low particulate air filter.

Emerging filtration technologies and filters such as nanofibres, filters with polytetrafluoroethylene membrane are likely to become prevalent over the coming years globally. The introduction of indoor air filtration with thermal comfort can be a possible avenue of future research along with expanding indoor environment monitoring and improving air quality predictions. New air filters and filtration technologies having better performance with low cost and high durability must be developed which can restrict multiple types of pollutants at the same time.

The systematic literature review approach used in this paper highlights the emerging trends and issues in cleanroom filtration in a structured and thematic manner, enabling future work to progress as it will continue to develop and evolve.

The purpose of this paper is to study the influence of fibre properties on filtration behavior. Air pollution is a major threat to human beings due to industrialization and urbanization. Among various particles in the atmospheric air, PM 2.5 causes various respiratory problems to human beings and also causes premature engine wear. The primary importance for the filters is higher filtration efficiency with lower pressure drop.

In this research, nonwoven filters were developed with different diameters of polyester fibres such as 0.8d, 1.2d and 6d fibres and different proportions of fibres were used. The Kuwabara cell model was used to derive certain parameters and its effects were analysed. The effect of basis length, solid volume fraction and porosity on filtration behavior was discussed in detail.

The filtration efficiency is higher for particle size from 1–3 µm, when different layers of polyester fibres are used with coarser fibres as the top layer and finer as the bottom layer. The filtration performance is better for layered nonwoven than unimodal nonwoven. The higher proportion of micro-denier fibres results in higher filtration efficiency with higher pressure drop.

The proposed research is more suitable for the particle size of more than 1 µm because of the fibre diameters and its achievable porosity. The filtration efficiency can be increased further by increasing the mass per unit area, which also increases the pressure and is not recommended.

The effect of triple-layers with different diameters of fibres on filtration was analysed. Due to the variation in diameters of fibres in different layers, the filtration performance varies.

The purpose of this paper is to fabricate a high-performance filtration electrospun nanofiber membrane with antibacterial function. The Ag nanoparticles (AgNPs) gotten by reducing AgNO₃ act as antimicrobial agent. Then the AgNPs/Polyacrylonitrile (AgNPs/PAN) composite nanofiber membrane was prepared by electrospinning.

The electrospun Ag/PAN composite membrane was prepared by one step, in which the Ag particles were acting as antibacterial agent and PAN nanofiber as the upholder of the composite mat. AgNPs were obtained by reducing AgNO3 in N,N-Dimethylformamide (DMF) solution at high temperature. Meanwhile, the PAN particles were added to DMF solution and dissolved. Then the Ag/PAN nanofiber was obtained by electrospinning.

The thinner nanofiber can be produced with PAN concentration of 12 per cent and AgNPs concentration of 10 per cent. Finally, the filtration resistance of the composite membrane with antibacterial property is as high as 99.1 per cent, and the filtration efficiency is only 83 Pa. Therefore, the AgNPs/PAN composite membrane is the ideal choice for air filtration with antibacterial property.

The AgNPs/PAN composite nanofiber membrane has high filtration performance for particulate matter (PM)25 and outstanding antibacterial property to Escherichia coli and Staphylococcus aureus, which can be used with masks, air-conditioning filters (including car air-conditioning filters), window screening and other similar objects.

This paper aims to discuss the development of a software tool UniverFilter™ which is capable of geometrical modelling of 3D woven fabrics, interfacing with computational fluid dynamics tools to numerically determine the fluid (and more specifically liquid) flow path and simulating the filtration process by introducing particles of various shapes and sizes.

The method employed in creating the software tool is based on geometrical modelling of the single‐layer woven fabric with monofilament yarns, numerical analysis of the fluid‐flow problem, and mathematical modelling of the forces exerted on particles to accurately predict the settlement of such particles on the fabric. In the case of particle motion, a Lagrangian approach is used.

Creation of a software tool capable of simulation and modelling the filtration process through woven fabrics is the primary achievement. The effect of geometrical parameters of the woven fabric on fluid flow utilizing the results from fluid pressure and fluid velocity on the fabric show that the fluid flow is significantly influenced in the interstices and chamber downstream by the fabric. Fluid‐flow resistance and pressure loss are obtained from the results of fluid velocity and pressure. The results from the fluid pressure on the fabric could also be employed to more accurately predict how pore shapes and sizes are transformed.

Creation of a modelling tool for filtration through woven fabric media. This software is the foundation of establishing a standalone tool with the capability to design, test and improve fabric filter design for more efficient filtration properties.

ENGINE lubricating oil filtration is not an exact science. Despite recent advances, detailed understanding of how filters and filtration systems operate is sparse, yet filters are known to facilitate dramatic reductions in engine wear. This paper relates the size of contaminants found in used oil to the magnitudes of the oil films between the lubricated components, in order to define the required filtration level in engines. The results of wear tests with oil contaminated by small particles are used to confirm the filtration requirement.

BEFORE the war scientific filtration as applied to aircraft was a little known subject. The prime concern of the people developing aircraft in those days was the attainment of higher power output, ceiling and maximum speed. More streamlining was the cry and, although filters were available, they were rarely used.

Given the COVID-19 Pandemic outbreak and the role of medical textiles for protection, this study aims to identify the leading research foci on using textile materials for personal protection in pandemic situations.

A systematic review and systemic analysis of the literature on the subject were performed using the process knowledge development – constructivist (ProKnow-C) methodology.

A bibliographic portfolio with 16 relevant studies was obtained. This portfolio represents the main focus of this research field, including the main filtration mechanisms, ways of disinfecting N95 respirators and proposed methods to evaluate the filtration efficiency of different materials with potential for mask development.

To the best of the authors’ knowledge, this is the first time the ProKnow-C methodology was used in the textile field. Thus, future studies can benefit from using the Proknow-C for selecting and analyzing relevant textile studies following a systematic approach.