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Сьогодні найбільш зручним та поширеним варіантом очищення та доочищення питних вод є встановлення систем зворотного осмосу безпосередньо в точках водовідбору. При експлуатації систем зворотного осмосу більшість власників не переймаються негативними наслідками використання таких систем. Адже після 3-6 місяців використання механічних фільтрів першого ступеню обробки води такі фільтри викидаються разом з іншим побутовим сміттям. Вони становлять значну загрозу для довкілля. На сьогодні в Україні не існує компаній чи організацій, які б займалися збором та утилізацією таких фільтрів. Цей напрямок є неосвоєним. Практично відсутні відповідні дані і в науковій літературі. Якщо зважити на те, що лише в м. Києві за нашими підрахунками сьогодні експлуатується біля 88 тис. побутових систем зворотного осмосу, то легко порахувати, що протягом року в довкілля потрапляє 176 тис. картриджів загальним об’ємом поліпропілену 105 м3 . Загальну шкоду для довкілля від картриджів навіть одного міста важко уявити. Тому питання регенерації механічних фільтрів систем зворотного осмосу є достатньо актуальним і важливим на сьогодні. Метою даної роботи є розробка екологічно безпечної технології регенерації механічних фільтрів з можливістю їх багаторазового використання. У цій статті висвітлюються результати досліджень з регенерації механічних фільтрів, наводиться характеристика процесу очищення шляхом використання сірчаної кислоти, показуються варіанти екологічно безпечної переробки відходів з такої регенерації. Today, the most convenient and widespread option for cleaning and purifying drinking water is to install reverse osmosis systems directly at the water intake points. However, the use of reverse osmosis systems has disadvantages associated with the frequent need to replace their elements. The article discusses the competitiveness of negative impact on the environment of reverse osmosis systems and ways to regenerate filters with the possibility of their reuse. Currently, there are no companies or organizations in Ukraine that would collect and dispose of such filters. This direction is undeveloped. There are practically no corresponding data in the scientific literature. If you take into account the fact that, according to our calculations, about 88,000 domestic reverse osmosis systems are in use today in Kyiv alone, it is easy to calculate that 176,000 polypropylene cartridges with a total volume of 105 m3 of polypropylene enter the environment during the year. The article presents method of regeneration of mechanical filters from iron compounds and other harmful impurities deposited on the surface and pores of the filter during operation. Studies of the jet sulfuric acid as a cleaner have confirmed its effectiveness and sufficient safety for further processing of cleaning products as an additive to cement. To establish the minimum residual concentration of iron in the mother liquor, a cycle of experiments was conducted and it was established that pH 4.0-4.5 can be considered optimal, at which the content of iron ions is at the level of their content in drinking water. There was made an estimation of acid. Technologies of large-scale cleaning used filters can be beneficial and cost-effective.. The results of the experimental study make it possible to develop a treatment plant with an automated system for dosing acid and measuring acidity.

A new class of drill-strings is proposed for attenuating undesirable vibrations to ensure effective operation. The drill-string is provided with passive periodic inserts, which are integrated with sources of local resonance (LR). The inserts make the drill-string act as a low frequency pass mechanical filter for the transmission of vibration along the drill-string. Proper design of the periodic inserts with sources of LR tend to shift these stop bands towards zones of lower frequencies to enable confining the dominant modes of vibration of the drill-string within these bands. In this manner, propagation of the vibration along the drill-string can be completely blocked. A finite element model (FEM) is developed using ANSYS to investigate the bandgap characteristics of the proposed drill-string with sources of LR. The developed FEM accounts for bending, torsional, and axial vibrations of the drill-string in order to demonstrate the effectiveness of the periodic inserts with LR in simultaneous control of these combined modes as compared to conventional solid periodic inserts, which are only limited to controlling bending vibrations. The effect of the design parameters of the periodic inserts with LR on the bandgap characteristics of the drill-string is investigated to establish guidelines of this class of drill-strings.

A differential pressure fiber optic infrasound sensor based on a mechanical filter was developed, for the detection of infrasound within the frequency range of 0.01--1 Hz. The sensing unit employs a miniature polyphenylene sulfide (PPS) diaphragm which is fixed onto a glass ferrule. An extrinsic Fabry-Perot (F-P) interferometer was fabricated between the optical fiber end face and the PPS diaphragm, and a mechanical filter structure introduced to improve the minimum detectable frequency down to 0.005 Hz. Experimental results indicate that this infrasound sensor shows a favorable frequency response for infrasound signals between 0.01 and 1 Hz, and it exhibits an average minimum detectable pressure (MDP) of 88.85 mPa·Hz−1/2. Our platform provides a promising solution for sensors in infrasound signal detection applications.

In the article the questions of development of construction of the closed ventilation and filtering system (CVFS) are considered on cleaning of air-gas mixture at deposition. The offered system consists of gas in-take, filters, containers for assembling of hard parts, hard constituent of welding aerosol (TSSA), by the gaseous constituent of welding aerosol (GSSA) and corps, special vent system with adjusting of speed and volume of extraction. Conducted research for cleaning of welding aerosols (SA) at deposition of high wear proof alloys of type of sormite with the use of the CVFS. Special CVFS is used, filters in particular mechanical, electric, chemical (sorption). Extraction of air-gas mixture from the area of melting of electrode and welding bath of is carried out by the pipe of small diameter, with adjusting of speed and volume of extraction passes the system of filtration the special vent system where clears up from TSSA. Thus cleared gas mixture is used as gas defense at depositing. It is necessary it is not simple to catch SA, but to filter in the closed system, clean and give filtered clean y air in the area of deposition, technology and metallurgical properties of process of depositing must not be broken here. Features of the mechanical cleaning are in technologies of deposition, characterized that air-gas mixture has a temperature which influences on a sorbent. The mechanical cleaning by the centrifugal chamber of cleaning (CCC) is the modernized cyclone filter where centrifugal forces and gravities were used. Differs from existent cyclic filters a presence by a conical spiral insertion and rearranged surface of cone which engulfs it. In the entrance tangential union coupling appears, divided aero mixture into a few streams of entered in a spiral insertion. In the electric filter (electrostatic) electric forces operate on particles and gas molecules (based on the phenomena ionization of gas molecules, by an electric charge in the electric field). An electric charge is revealed to the particles, and they under the action of the electric field are besieged from a gas stream. If such gas, containing the several of transmitters of charges, to place between electrodes, connected with the source of high voltage, ions and electrons will begin to move to on power the field lines . This is important during neutralization of GSSA

When conducting dynamic tests, when simulating shock effects, the measurement system - from the sensor to the data acquisition unit is subject to significant overloads. In this circuit, the accelerometer is the most vulnerable link. Therefore, piezoelectric accelerometers have become widely used in measuring shocks as more reliable and durable, but they also have a number of disadvantages. Thus, under broadband vibration effects, excitation in the region of mechanical resonance is observed. That is, the material of the sensor crystal may not have an excessive mechanical load, but generate a large amount of output charge due to the resonance of the sensor. This increases the electrical signal and can lead to saturation or, in many cases, damage to the signal shapers and amplifiers following the sensor. The result of such modes of operation is the loss of data due to the displacement of direct current over time. There is often a shift of the zero level of the output signal. When piezoelectric elements are in resonance, there may be a relative displacement of the sensing element. This state of overload leads to the appearance of parasitic output charges, which leads to a change in the generated charge in a short period of time. Due to mechanical overload, under the action of high-intensity shocks, physical destruction of the sensor is also possible. In many cases, the use of mechanical filters made of viscoelastic materials, which are placed between the object of measurement and the piezoelectric accelerometer (sensor), prevents the undesirable consequences of these shortcomings and improves the process of measuring shocks. The use of mechanical filters made of viscoelastic materials makes it possible to significantly reduce the amplitude of oscillations of the piezoelectric accelerometer (over -12 dB) and shift its resonant frequency towards higher frequencies. That is, the use of mechanical filters significantly reduces the mechanical load on the sensor, which makes the process of measuring vibration (especially shock) more predictable.

The possibility of using quartz sand as a filter material for mechanical filters in the schemes of preliminary water treatment in water treatment plants with coagulation and liming at thermal power plants is considered. Comparative experiments on filtering water through quartz sand at the laboratory bench of an operating thermal power plant showed the absence of leaching of silicic acid from sand at pH = 10.0–10.2 and a filtration rate of 7 m/h. The turbidity of the filtrate is close to zero, and the quality of the water obtained after filtering through quartz sand is higher than when filtering through hydroanthracite. Hydroanthracite is characterized by relatively high abrasion and increased cost in comparison with quartz sand. Model experiments were carried out in a wide pH range when filtering water through sand, which showed the absence of a significant release of silicic acid into water. We studied the long-term interaction of water with quartz sand at pH 12, in which there is no intensive release of silicic acid compounds into water. Studies of the quality of the filtrate of mechanical filters loaded with quartz sand and hydroanthracite at a high pH of the treated water were performed. To prevent silicic acid compounds from entering clarified water, it is recommended that the first portion of the filtrate of the mechanical filters be discharged before being put into operation after a long period of inactivity. Recommendations on the use of quartz sand as a filter material in mechanical filters of the preliminary water treatment scheme at thermal power plants are presented.

Micro-electromechanical systems (MEMS) bandpass filters based on arrays of electrostatically driven coupled beams have been demonstrated at MHz frequencies. High performance follows from the high Q-factor of mechanical resonators, and electrostatic transduction allows tuning, matching and actuation. For high-order filters, there is a conflict between the transduction mechanism and the coupling arrangement needed for dynamic synchronization: it is not possible to achieve synchronization and tuning simultaneously using a single voltage. Here we propose a general solution, based on the addition of mass-loaded beams at the ends of the array. These beams deflect for direct current (DC) voltages, and therefore allow electrostatic tuning, but do not respond to in-band alternating current (AC) voltages and hence do not interfere with synchronization. Spurious modes generated by these beams may be damped, leaving a good approximation to the desired response. The approach is introduced using a lumped element model and verified using stiffness matrix and finite element models for in-plane arrays with parallel plate drives and shown to be tolerant of the exact mass value. The principle may allow compensation of fabrication-induced variations in complex filters.

This research presents the theoretical and experimental studies for cylindrical and conical periodic structures to control longitudinal wave motion. Many relevant researches exist to stop and pass a certain frequency wave without active devices with periodic structures called metamaterials. To modify or control longitudinal wave propagation, i.e., passing or blocking mechanical wave within specific frequency ranges, repeated mass-spring systems or metamaterials can be applied. By integrating a few identical structural components to form a whole structure, it is possible to make a mechanical filter for wave propagation. Most studies rely on straight bar with cylindrical structure. Thus, with a unit cell that have a cylindrical and conical structure, this research presents the extensions toward the studies of the wave motions for straight and curved bars with finite element simulations and experiment studies. The results show that the hybrid cylindrical and conical periodic structures can be effective in terms of wave motion control and stiffness.

The vibroisolation and wave properties of the lattice consisting from the beam elements and lumped masses located in the lattice nodes are studied. The finite element method is used to obtain the lattice dynamic model and its dispersion equation in analytical form. It is shown that such a lattice is a bandpass mechanical filter, and the opacity bands of the harmonic signal depending on the direction of the wave propagation is found. The limiting minimum and maximum frequencies for the harmonic signal transmission are also obtained. It is shown that the addition of discrete inclusions to the lattice increases its vibroisolation properties in low-frequency range.

We develop tunable optical filters with dual-frequency nematic liquid crystal optical retarders to enable fast switching between the passed wavelengths. The filters are composed of a series of two liquid crystal optical retarders. We select the specific thicknesses of the liquid crystal retarders and use individual biasing schemes to continuously tune the wavelength and bandwidth of the filter. This enables fine-tuned filter switching speeds of filter operation in the ms regime. We present theoretical predictions and experimental results for the electro-optical filter characterization as well as an example application for our filter in total internal reflection fluorescence microscopy. We find that our filter switching speeds can be as short as a few ms, an order of magnitude improvement over typical mechanical filter wheel switching speeds. The quality of our fluorescence images is similar to those obtained by conventional filters.

Cryomodules (CM) represents edge-frontier assemblies in particle physics research field. The road transportation of CM is a critical phase during which the structures can be subjected to significant dynamic loads. It is therefore necessary to design a Transportation Tool (TT) equipped with an appropriate suspension system. This work describes the approach adopted for the design of the TT for the CM PIP-II SSR1 (Proton Improvement Plan-II – Single Spoke Resonators 1), which is firstly introduced in the CM research field. Initially a Finite Element (FE) model was developed, considering the main sub-assemblies of the CM. However, this model was not suitable for the design of the TT due to the high computational burden. For this reason the model was exported as a Modal Neutral File and imported into a MultiBody software (MB) where the remaining components were modeled as concentrated stiffnesses or rigid bodies. The MB model thus obtained has drastically reduced the calculation time, proving to be fundamental in the TT iterative design phase, which involves the use of Helical Isolators (HI) performing the function of mechanical filters. To validate the effectiveness of TT in reducing dynamic loads, a 3D acceleration profile measured during the transport of a similar cryomodule (Linear Coherent Light Source II, LCLS-II) was used. Furthermore, the results of the MB model were used to perform the structural verification of some critical components of the CM.

A lumped-parameter mechanical system consisting of a chain of physically related rigid bodies, each of which has one rotational degree of freedom, is considered. It is shown that the inertialess elastic elements connecting the absolutely rigid bodies of the chain can be chosen so that the mechanical structure acquires the properties of a so-called absolute mechanical filter. The motion of any inertial element of this system is described by the equation of a classical harmonic oscillator with one degree of freedom. Using the system considered as an example, it is shown that there is a relationship between the models of classical and quantum mechanics. From the positions of modern classical mechanics, this lumped-parameter system confirms the well-known Einstein’s hypothesis theoretical physics that a rigid body is a system of independent oscillators.

The Advanced Mo-based Rare process Experiment utilizes a cryogen-free dilution refrigerator to operate its low-temperature detectors. Mechanical vibration originating from its pulse tube refrigerator can affect the detector performance. A mechanical filter system has been installed between the 4K and still plates with eddy current dampers in addition to a spring-loaded damping system previously installed below the mixing chamber plate of the cryostat. The filters significantly mitigated vibrations and improved the detector signals.

This study introduces a novel framework for local resonant systems to low bandgap frequencies without greatly increasing spatial penalties in grid structures. The proposed double-spiral resonator (DSR) consists of a pair of spiral spring-like structures and a rigid plate acting as the “mass” of the oscillating system, which can serve as an effective mechanical filter. A rapid and accurate calculation based on the stiffness matrix method is proposed to precisely predict the fundamental resonant frequency of the resonator. Periodic installation of these resonators in a grid-like beam structure can lead to the formation of a new type of metastructure that possesses negative effective properties. Investigations on the bandgap characteristics of the proposed metastructure are conducted using the finite element method. It is found that a low-frequency resonant-type bandgap is present in such a structure. Changing the thickness of the central mass or the number of parasitic beam segments enables the manipulation of the bandgap location. The validity of the analytical results is evaluated via comparison with the finite element results and experimental measurements. By using multiple resonators with similar resonance frequencies, the attenuation bandwidth can be effectively broadened. The physics behind wave attenuation can be realized by introducing a negative effective mass density. The results demonstrate that the proposed structure exhibiting unique dynamic characteristics can successfully attenuate undesired structural vibrations at low frequencies. It may be concluded that this DSR can be used as an alternative to current vibration filtering systems.

Elastomeric materials are used as shock isolation materials in a variety of environments to dampen vibrations and/or absorb energy from external impact for minimizing energy transfer between two objects or bodies. Some applications require the shock isolation materials to behave as a low-pass mechanical filter to mitigate the shock/impact at high frequencies but transmit the energy at low frequencies with minimal attenuation. In order to fulfill this requirement, a shock isolation material needs to be carefully evaluated and selected with proper experimental design, procedures, and analyses. In this study, a Kolsky bar was modified with pre-compression (up to 15.5 kN) and confinement capabilities to evaluate low-pass shock isolation performance in terms of acceleration attenuation through a variety of elastomers. The effects of preload and specimen geometry on the low-pass shock isolation response were also investigated.

Modern wireless communication systems typically employ multiple frequency bands for several standards. A new class of miniaturized ring filters with tuning capability is introduced for this purpose. The proposed filter structure is based on a single multi-mode resonator with variable section impedances in microstrip technology. The bandwidth of the filter can be significantly extended to cover the whole ultra wideband (UWB) frequency range with high adjustability. Moreover, a tunable bandnotch is introduced within the filter response, which can be arbitrarily placed according to the required application. Varactor and PIN diodes are also utilized to facilitate a high tuning capability throughout the different filter characteristics with respect to bandwidth, center frequency, and bandnotch frequency. Based on the symmetry of the filter, even-odd mode analysis is applied to investigate the different filter design characteristics. In addition, a comprehensive transmission line model is investigated within this paper which showed excellent agreements with full-wave simulations and measurements. The implemented UWB filter is investigated with respect to its frequency-domain characteristics and group delay response. The realized filter has a fractional bandwidth of more than 119% with a low group delay. All measured results are in a very good agreement with analysis and simulations. The overall filter dimensions, including housing, do not exceed 25 mm $\times 25$ mm.

The design of analog filter using active building block has been gained significant attention and has become an interesting research topic. A five-inputs single −output voltage-mode universal biquadratic filter using active building block, namely voltage differencing differential difference amplifier (VDDDA) is presented in this paper. The proposed filter consists of two VDDDAs and two grounded capacitors. The presented circuit has high impedance for all input voltage nodes and low impedance for output voltage node which is ideal for cascade in voltage-mode circuit without the use of buffer circuits. It can provide five output voltage functions which are band-pass (BP), low-pass (LP), band-reject (BR), high-pass (HP) and all-pass (AP) responses. For high-pass and band-pass functions, the inverting and non-inverting response can be achieved. The matching condition, the inverting and double gain amplifier are not required which is easy to select the output response by digital method. The natural frequency and quality factor can be electronically tuned that is attractive for microcomputer or microcontroller controllability. To verify the validity of proposed filter, the PSPICE simulation and experimental results using VDDDA constructed from commercially available IC are included. The measured results agree well with theoretical expect.

An on-chip strain measurement device is demonstrated that harnesses precision frequency measurement to precisely extract sub-nm displacements, allowing it to determine the residual strain in a given structural film with best-in-class accuracy, where stress as small as 15MPa corresponds to 2.9nm of displacement. The approach specifically harnesses a spoke-supported ring structure (cf. Fig. 1) surrounded both inside and outside by balanced capacitive-gap transducers that pull its resonance frequency according to strain-induced changes in inner and outer electrode-to-structure gap spacing. The use of a ring structure with balanced electrodes further eliminates uncertainty in the starting gap spacing, which in turn enhances accuracy. The importance of attaining such accuracy manifests in the fact that knowledge of residual strain might be the single most important constraint on the complexity of large mechanical circuits, such as the mechanical filter of [1].

Пояснювальна записка 88 с.; 7 рис.; 17 табл.; 20 посилань; 2 додатки. У бакалаврському проекті проаналізовані методи очищення стічних вод від йонів міді, запропоновано адсорбційний метод очищення стічної води. Наведено фізико-хімічні основи процесу адсорбції, проведені конструктивні та технологічні розрахунки основного та допоміжного обладнання. На підставі зроблених розрахунків обрано необхідне устаткування. Наведена технологічна схема та її опис. Запропоновано схему автоматичного регулювання та контролю виробництва. Надано економіко-організаційний розрахунок з обґрунтуванням вибору методу очищення води від йонів міді. Розглянуто безпечні умови проведення виробничого процесу, наведено аналіз і джерела виникнення відходів, надано можливі варіанти їх утилізації. В інноваційній частині наведені результати досліджень адсорбційної активності синтезованих сорбентів. Побудовано кінетичні криві за отриманими даними. Explanatory note 88 pp.; 7 fig.; 17 tab.; 20 lib.; 2 appendices. In the bachelor's project, methods for purifying wastewater from copper ions were analyzed, an adsorption method for purifying wastewater was proposed. The physicochemical principles of the adsorption process were given, the constructive and technological calculations of the main and auxiliary equipment were carried out. The necessary equipment was selected on the basis of calculations that mentioned above. The process scheme was described. The scheme of automatic control and production control was offered. Economical and organizational calculations with justification of a choice of method of water purification from copper ions were provided. Safe conditions of the manufacturing process have been considered. Analysis of the sources of waste were provided, possible variants of their utilization were given. The innovation part presents the results of studies of the adsorption activity of the synthesized sorbents. The kinetic curves were constructed from the data obtained. Пояснительная записка 88 с.; 7 рис.; 17 табл.; 20 ссылок; 2 приложения. В бакалаврском проекте проанализированы методы очистки сточных вод от ионов меди, предложено адсорбционный метод очистки сточных вод. Приведены физико-химические основы процесса адсорбции, проведенные конструктивный и технологические расчеты основного и вспомогательного оборудования. На основании произведенных расчетов выбрано необходимое оборудование. Приведена технологическая схема и ее описание. Предложена схема автоматического регулирования и контроля производства. Предоставлено экономико-организационный расчет с обоснованием выбора метода очистки воды от ионов меди. Рассмотрены безопасные условия проведения производственного процесса, приведены анализ и источники возникновения отходов, предоставлено возможные варианты их утилизации. В инновационной части приведены результаты исследований адсорбционной активности синтезированных сорбентов. Построены кинетические кривые по полученным данным.