Filter Elements Research Articles

Research of the possibility of using filter materials with orthotropic structure based on woven nets for cleaning diesel fuel

A comparative analysis of the characteristics of experimental samples of filter materials with an orthotropic structure based on woven meshes (FMTS) and standard paper filters was carried out, which confirmed the possibility of using filter elements from FMTS for fine purification of diesel fuel in automotive equipment. Promising directions for further research in the development of effective FMTS are given.

Creation of a universal housing for a liquid purification filter made of corrosion-resistant steels

Scientists from different countries are engaged in the development of new or improvement of existing water purification technologies. At the same time, not enough attention is paid to the development of equipment for water purification and technologies for their manufacture. The article presents a model of a universal filter housing for cleaning liquids from solid particles. Mechanical filters of cartridge or bag type can be used as filter elements. The main supporting element of the filter housing is a thin-walled cylindrical flask. The use of rotary rolling in the process of manufacturing a cylindrical flask makes it possible to reduce the negative effect of welded seams and increase the strength of the cylindrical shell. The results of experimental studies on assessing the effect of the relative deformation value along the wall thickness during rotary rolling of steel cylindrical shells on their strength and stability are presented.

COMPARATIVE ASSESSMENT OF BACTERIAL PERMEABILITY OF A PERSONAL PROTECTIVE RESPIRATORY EQUIPMENT AT DIFFERENT DURATIONS OF ITS CONTINUOUS OPERATION.

The aim: To establish the level of antibacterial protection of the studied personal protective respiratory equipment set and its main components and compare antibacterial resistance of the personal protective respiratory equipment set in the presence and absence of filtering components. Materials and methods: The proposed methodology for assessing biological protection parameters is based on testing the permeability of personal respiratory protection equipment for bacteria by the method of serial dilutions. Also additional culturing of separate components of the protective set on a separate media is carried out. The experiment was also repeated in the absence of filtering elements and when they were replaced by gauze masks. Results: The use of a fully equipped pneumatic helmet counteracted the penetration of the bacterial aerosol, which was manifested in the absence of growth on the media. The results obtained with the full configuration, as well as the indicators of the spread of bacteria when removing the filter elements and replacing them with gauze masks, showed that the device creates sufficient positive air pressure inside. The latter becomes a restraining factor that does not allow microorganisms to penetrate through the lower circuit. Conclusions: Increasing the duration of continuous operation of the conceptual model up to 24 hours, increasing the bacterial load on the filters do not lead to a deterioration in the properties of antibacterial protection. Bacterial aerosol did not penetrate into the inner space of pneumatic helmet.

Principle and Experimental Study of Flow Noise Reduction for Underwater Vehicle Hull-Mounted Sonar

When the underwater vehicle is sailing at high speed, the noise of flow becomes one of the principal background noises of the hull-mounted sonar, and suppressing the flow noise is an important way to further develop the detection execution of the hull-mounted sonar. In this paper, by establishing a physical model for the analysis of flow noise, The theoretical calculation of the fluctuating level of noise acquired by a plane element sensor imbedded in an rubbery layer is performed, and the impact of different wave-number filter elements such as sensor receiving area and rubbery layer on reducing turbulent noise is discussed, and then, the effectiveness of the flow noise reduction is verified through the measurement in a large-scale flow noise test tunnel.

Methodology of assessing the quality of mask filter elements for protection of people, and their vital functions in case of fire

This abstract delves into an investigation concerning the toxicity of the gaseous environment encountered in the context of fires within public structures, encompassing shopping malls and entertainment centers. These fires engender the release of a host of highly toxic gases, prominently including phosgene, carbon monoxide, and hydrogen cyanide. It is noteworthy, however, that prevailing portable filtering self-rescue masks employed during the evacuation from fire-stricken areas do not offer protection against phosgene. This discrepancy is attributed, in part, to the absence of stipulated requirements for safeguarding against phosgene within the regulatory documentation governing mask specifications. In response to this, a comprehensive methodology has been devised for evaluating the protective attributes of filtering and absorbing components, concomitant with the establishment of a delineated roster of gases to serve as benchmarks for assessing reliability. The culmination of these research has resulted in the development of a novel fibrous material and a respiratory mask design, specially tailored to protect against the toxic gases encountered during fires within public structures. These innovations can improve the protective effectiveness of masks, making them better suited to protect people in such dangerous situations.

Manufacturing Technology of Multilayer Metal Filters

The article presents methods for obtaining micro-holes in the manufacture of fine metal filter elements. The analysis of the results of experimental studies of filter samples with holes made by electron beam and electroerosion perforation methods is carried out. The advantages of using multilayer structures in the manufacture of filters are substantiated. The research works carried out contribute to improving the manufacturability of products of new generations of technology, which is important for mechanical engineering.

Improved Interleaved Single-Ended Primary Inductor-Converter for Single-Phase Grid-Connected System

The generation of electricity based on renewable energy sources, particularly Photovoltaic (PV) system has been greatly increased and it is simply instigated for both domestic and commercial uses. The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power. An improved interleaved Single-ended Primary Inductor-Converter (SEPIC) converter is employed in proposed work to extricate most of power from renewable source. This proposed converter minimizes ripples, reduces electromagnetic interference due to filter elements and the continuous input current improves the power output of PV panel. A Crow Search Algorithm (CSA) based Proportional Integral (PI) controller is utilized for controlling the converter switches effectively by optimizing the parameters of PI controller. The optimized PI controller reduces ripples present in Direct Current (DC) voltage, maintains constant voltage at proposed converter output and reduces overshoots with minimum settling and rise time. This voltage is given to single phase grid via Voltage Source Inverter (VSI). The command pulses of VSI are produced by simple PI controller. The response of the proposed converter is thus improved with less input current. After implementing CSA based PI the efficiency of proposed converter obtained is and the Total Harmonic Distortion (THD) is found to be . The dynamics and closed loop operation is designed and modeled using MATLAB Simulink tool and its behavior is performed.

Ecological impact and results of the study of motor oils of internal combustion engines by conducting tribomechanical stabilizers

This article deals with the problem of the influence of motor oils of agricultural tractors used in agro-industrial complexes on the environment and the results of experimental and operational tests of the introduction of tribomechanical stabilizers into motor oils of a gas engine based on a diesel engine. Prospects for the continuous introduction of additives into the lubrication system. When a diesel engine is running, up to 75% of the additives work out in 10 hours, within 80 hours. The alkalinity of the oil decreases from 3 to 1,4 Mg KOH/g. When switching to a new lubrication mode, the wear of parts of the engine piston group is reduced by 20-25% and the service life of the coarse oil filter elements is increased by 30-40%, deposits of carbon deposits and varnish on the engine pistons are reduced by 30 %. It was revealed that the studied oil characteristic - base number with continuous input of tribomechanical stabilizers has a value 1.5 times higher compared to samples of oils used in the absence of continuous input of tribomechanical stabilizers.

Design of a Compact GaN Power Amplifier With High Efficiency and Beyond Decade Bandwidth

This letter presents a power amplifier (PA) design and network synthesis approach to achieve wideband and efficient performance with a very compact circuit size. A design method is presented in detail to convert a canonical filter-based high-order matching network to the proposed matching configuration with transistor parasitic and packaged elements absorption, and a compact passive network footprint. As a proof of concept, a prototype GaN HEMT PA is implemented. Starting from a fourth-order output network filter, the inductances and capacitance of the filter elements are re-organized to model, and thus absorb the output parasitics of the transistor, leading to a compact footprint with only four transmission lines. The measured results show that the prototype PA achieves an output power of 41.9–44.3 dBm and a 55%–74% drain efficiency, over a record-high decade bandwidth (0.35–3.55 GHz).

Influence of drying method on the migration of the binder and the properties of a high-temperature filter based on aluminosilicate fibers

Ceramic filter elements based on aluminosilicate fibers were produced by vacuum forming, using various drying methods. Microwave drying and freezing followed by drying have been used as methods to reduce binder migration. The microstructure of the obtained filter elements, tensile strength and aerodynamic resistance were analyzed. The obtained characteristics were compared with the characteristics of filter elements made using convective drying. Ill. 6. Ref. 33. Tab.

Simulation Optimization of an Industrial Heavy-Duty Truck Based on Fluid–Structure Coupling

In order to realize the sustainable development of the field of automotive industrial engineering and reduce the emissions of heavy-duty trucks (HDTs), a simulation analysis method that combined fluid–structure coupling and a discrete phase model was proposed in this study. The pressure, velocity, and other parameters of an HDT air filter and its cartridge were analyzed by using CFX and the Static Structure module in the ANSYS software. The results showed that under six different flow rates, the error between the simulation results and the test results was basically less than 3% (the maximum error was 3.4%), and the pressure distribution of the fluid in the air filter was very uneven, leading to a severe deformation of 3.51 mm in the filter element. In order to reduce the pressure drop of the air filter and the deformation of the filter element, the position of the air inlet duct, the height of the filter element, and the number of folds of the air filter were optimized in this study. The optimization results showed that when the rated flow was 840 m3/h, compared with the original structure, the pressure drop of the air filter was reduced by 445 Pa, the maximum deformation of the filter element was reduced by 54.1% and the average deformation is reduced by 39.8%. After the optimization, the structural parameters of the air filter were as follows: the position of the air inlet moved down 126 mm along the shell, the filter height was 267 mm, and the pleat number of the filter element was 70. The simulation method and optimization design method of an air filter based on fluid–structure interaction presented in this study can be used to reduce the pressure drop, improve the engine performance, and reduce the amount of harmful emissions.

The Effect of Powder Granulometric Composition on the Structure and Size of the Porous Ceramics Channels

The paper studies the structure of the end-toend channel network of porous ceramic specimens. Electro corundum powders with different granulometric compositions were used to manufacture ceramics, which was achieved by grinding electro corundum in a ball mill for various time periods. The characteristic dimensions of end-to-end channels of porous ceramics were determined. A relationship was established between the granulometric composition of powders and the properties of theend-to-end channel network in porous ceramics. It is shown that the largest pores, whose size monotonically depends on the powder average particle size, comprise most of the pore space of a permeable ceramic manufactured, using narrow-fraction powders. On the other hand, if a powder with polydisperse particle size is used for ceramics manufacturing, a wide range of pore channel sizes is observed. The smaller the pores, the greater their contribution to the ceramic pore space. It should be noted that such information makes it possible to purposefully design materials with the required structure, which is most optimal for a particular product (filter elements, heat-insulating materials, etc.). Keywords — electrocorundum, permeable ceramics, end-toend channels, liquid extrusion porosimeter, granulometric powder composition, filter elements.

Dual-Path Coupled-Line Dual-Band Bandpass Filter with Synthesis

A dual-band bandpass filter topology based on the use of dual-path coupled lines is presented. It exhibits a 2nd order dual-band response with three transmission zeros that gives a wide separation of the passbands, and from the rejection bands. A simplified circuit diagram of the topology is proposed along with a global synthesis that can be used to control the transmission zeros, the center frequency, and the bandwidth of the passbands, by varying the length and impedance of the filter elements. The filter topology was implemented in the design of two dual-band microstrip filters on TRF45 substrate to validate the idea. Measurement results show that the center transmission zero is at 2.55 GHz, and the two passbands are centered at 1.81 GHz and 3.02 GHz. It provides isolation of up to 31 dB between the passbands. Keywords—Dual-mode, dual-band, microstrip, bandpass filters.

A novel dual switch DC/DC converter without reverse recovery problem

The traditional dual switch forward converter has a very large filter element and all the diodes on the primary and secondary sideshow the problem of reverse recovery and voltage oscillation. Therefore, this paper proposes a novel dual switch DC/DC converter with only one capacitor as the output filter, which reduces the number of magnetic elements and improves the power density. Besides, zero current turned on of main switches and zero current turned off of all diodes is achieved to solves the problem of parasitic oscillation and reverse recovery of the diodes. In this paper, the detailed analysis of the dual switch converter’s operating principle and characteristics are analyzed. Finally, according to the proposed converter, a prototype has been established in the lab, and the experimental results verify the validity of the analysis.

An active transverse energy filter to differentiate low energy particles with large pitch angles in a strong magnetic field

We present the idea and proof of principle measurements for an angular-selective active filter for charged particles. The motivation for the setup arises from the need to distinguish background electrons from signal electrons in a spectrometer of MAC-E filter type. While a large fraction of the background electrons exhibit predominantly small angles relative to the magnetic guiding field (corresponding to a low amount of kinetic energy in the motion component transverse to the field lines, in the following referred to as transverse energy) and pass the filter mostly unhindered, signal electrons from an isotropically emitting source interact with the active filter and are detected. The concept is demonstrated using a microchannel plate (MCP) as an active filter element. When correctly aligned with the magnetic field, electrons with a small transverse energy pass the channels of the MCP without interaction while electrons with large transverse energies hit the channel walls and trigger an avalanche of secondary electrons that is subsequently detected. Due to several drawbacks of MCPs for an actual transverse energy filter, an alternative detection technique using microstructured Si-PIN diodes is proposed.

Linked Metadata for FAIR Digital Objects Carrying Computable Knowledge

Linked Metadata for FAIR Digital Objects Carrying Computable Knowledge

Stability Analysis and Robust Control Method for LCL-Type Three-Phase Four-Wire Split Capacitor Inverter Considering Zero-Sequence Loop

In distributed generation systems, the inverter is the main power interface and its stability directly determines the reliable operation of the grid-connected system. As a typical topology for a three-phase four-wire inverter, the LCL-type three-phase four-wire split capacitor inverter (LCL-TFSCI) is taken as the research subject of this paper. Compared with the three-phase three-wire inverter, there is an additional zero-sequence path in the LCL-TFSCI. Therefore, it is not only necessary to consider the stability of the positive and negative sequence system, but there is also the need to consider the stability of the zero-sequence system when performing stability analysis for the LCL-TFSCI. In this paper, a small-signal impedance model considering the zero-sequence loop of LCL-TFSCI is firstly established. Subsequently, the instability risk is revealed when LCL-TFSCI is connected to the grid with parallel compensation capacitors. Through instability analysis, an impedance-reshaping method based on the complex filter and combined differential elements is proposed, which can reshape the impedance characteristic of LCL-TFSCI within the wide frequency range and expand the stability domain of the grid-connected system. Finally, the proposed method is verified by simulation and experiment.

Status and initial experiments of DRAGON-V facility for lithium-lead blanket technologies of hydrogen fusion reactors

A dual-coolant integrated experimental facility named DRAGON-V has been developed at the Institute of Nuclear Energy Safety Technology, Hefei Institute of Physical Science, Chinese Academy of Sciences, for the key technology research and performance evaluation of candidate liquid lithium-lead (PbLi) blanket of hydrogen fusion reactors. The loop is composed of a material test sub-loop and thermal-hydraulic test sub-loop, the design parameters are PbLi inventory 20 tons, PbLi temperature up to 550 °C, the maximum PbLi flow rate up to 40 kg/s. A novel cold trap system is designed to remove the suspended and crystalized impurities in PbLi fluid with three cooling zones and cross row arrangement of rod bundle filter elements. The paper describes the loop itself and its major components, initial loop testing, flow and measurement diagnostics and current experiments. The obtained test results of the loop and its components have demonstrated that the new facility is fully functioning and ready for experimental studies of material corrosion with/without a magnetic field, magnetohydrodynamic (MHD) effect, purification, heat and mass transfer phenomena in PbLi flows and can also be used in mock-up testing in conditions relevant to fusion applications.

Family of Non-Isolated High Step-Up DC–DC Converters Based on the Multi-State Switching Cell

This work presents a family of non-isolated high step-up dc–dc converters for high-power, high-current applications based on the multi-state switching cell (MSSC) and voltage multiplier cells (VMCs). Inherent advantages in the proposed topologies include reduced current and voltage stresses on the semiconductors, improved thermal distribution, good current sharing among the phases, and reduced dimensions of filter elements. Another relevant aspect is that the derived converters present modularity in terms of the possibility of extending not only the voltage gain, but also the rated power. A non-isolated dc–dc boost converter employing the four-state switching cell (4SSC) is thoroughly analyzed. Experimental results obtained from a 1.3-kW prototype are presented and discussed to validate the theoretical assumptions.

Fast data-driven computation and intuitive visualization of fiber orientation uncertainty in 3D-polarized light imaging

In recent years, the microscopy technology referred to as Polarized Light Imaging (3D-PLI) has successfully been established to study the brain’s nerve fiber architecture at the micrometer scale. The myelinated axons of the nervous tissue introduce optical birefringence that can be used to contrast nerve fibers and their tracts from each other. Beyond the generation of contrast, 3D-PLI renders the estimation of local fiber orientations possible. To do so, unstained histological brain sections of 70 μm thickness cut at a cryo-microtome were scanned in a polarimetric setup using rotating polarizing filter elements while keeping the sample unmoved. To address the fundamental question of brain connectivity, i. e., revealing the detailed organizational principles of the brain’s intricate neural networks, the tracing of fiber structures across volumes has to be performed at the microscale. This requires a sound basis for describing the in-plane and out-of-plane orientations of each potential fiber (axis) in each voxel, including information about the confidence level (uncertainty) of the orientation estimates. By this means, complex fiber constellations, e. g., at the white matter to gray matter transition zones or brain regions with low myelination (i. e., low birefringence signal), as can be found in the cerebral cortex, become quantifiable in a reliable manner. Unfortunately, this uncertainty information comes with the high computational price of their underlying Monte-Carlo sampling methods and the lack of a proper visualization. In the presented work, we propose a supervised machine learning approach to estimate the uncertainty of the inferred model parameters. It is shown that the parameter uncertainties strongly correlate with simple, physically explainable features derived from the signal strength. After fitting these correlations using a small sub-sample of the data, the uncertainties can be predicted for the remaining data set with high precision. This reduces the required computation time by more than two orders of magnitude. Additionally, a new visualization of the derived three-dimensional nerve fiber information, including the orientation uncertainty based on ellipsoids, is introduced. This technique makes the derived orientation uncertainty information visually interpretable.