A piezoelectric transducer in the form of a damped plate radiating into steel through a system of transition layers is considered. The algorithm for calculating the frequency response of the ...transducer is described, and its pulsed operation mode is investigated. A voltage pulse in the form of a half sine wave at the plate’s antiresonance frequency is selected as an electrical excitation signal. Some materials used for manufacturing certain transducer design elements are considered. Based on estimative calculations of the geometrical thicknesses of layers actually encountered in the practice of ultrasonic testing, their wave thicknesses are chosen. The data obtained is used to determine the shape of the emitter output signal. Calculations are carried out in a wide range of specific acoustic impedances of the wear plate.
The design of a tubular-type electrobaromembrane apparatus for cleaning process solutions of chemical plants is developed. The principle of operation of the apparatus is explained and the volume of ...the solution separation chambers is calculated. The merits of the developed design are increased rate of near-anode and near-cathode permeate removal and reduced permeate heating temperature and absence of stagnant zones in the permeate withdrawal path.
The effect of heavy sputtering and of neutron irradiation simulated by displacement damaging with of 20MeV W6+ ions on the optical properties of tungsten mirrors was studied. Ar+ ions with 600eV of ...energy were used as imitation of charge exchange atoms ejected from fusion plasma. The ion fluence dependence of the surface topography and the optical properties of polycrystalline, recrystallized tungsten (grain size 20–100μm) were studied by optical microscopy, interferometry, reflectometry and ellipsometry. Furthermore, after sputtering in total a layer of 3.9μm in thickness, the orientation and the thickness of the eroded layer of many individual grains was determined by electron backscattering diffraction and confocal laser scanning microscopy. Concluding from the obtained data the neutron irradiation, at least at the damage level would be achieved in ITER, has not to make an additional contribution in the processes developing under impact of charge exchange atoms only.
The relationship between non-monotonic concentration dependencies of the size of the dispersed phase (nanoassociates), physicochemical properties (specific electrical conductivity, pH), and ...fluorescence intensity (λ
ex
225 nm, λ
em
340 nm) of a multi-component dispersed system based on herbicide
N
-(phosphonomethyl)glycine and its effect on the development of some hydrobionts and on the inhibition of
Triticum vulgare
wheat root growth in the range of calculated concentrations 1·10
−19
−1·10
−3
g L
−1
is established for the first time. The obtained results indicate that coherent changes in fluorescence intensity, physicochemical properties, and bioeffects are related to the rearrangement of nanoassociates which accompanies the dilution of the systems.
A flat-chamber type of electrobaromembrane separation equipment is designed. A method is developed to calculate the effective separation area of the equipment that enables determination of the total ...performing area of the membranes for separating solutions and the usable area of cathode- and anode-adjoining membranes.
The absorption spectra of infrared radiation by membranes of AMN-P and OPMN-P brands are analyzed. In the spectra of the surface layer of the AMN-P membrane, there is a decrease in the relative ...intensity of the frequencies of the carbonyl group (1724 cm
–1
, 3392 cm
–1
for air dry). For the cellulose acetate AMN-P membrane, the number of hydrophilic OH groups increases, which changes its molecular structure and transport characteristics. In the infrared-radiation spectra of the surface layer of the OPMN-P membrane, the 1650–1670 cm
–1
band characteristic of C=O group shows changes in the frequency of the spectrum: for air-dry and water-saturated samples, it shifts from 1652 to 1666 cm
–1
, respectively. Interactions of carbonyl (C=O) and amide (H–N) groups form the supramolecular structure of polyamides. Changes in the infrared-radiation spectrum of the water-saturated sample of the OPMN-P membrane can be explained by the fact that the C=O…–…H–N bonds of the amide fragment do not break. Therefore, membrane swelling partially affects the structural rearrangement of the polyamide at the supramolecular level. In the electro-nanofiltration separation of an aqueous solution of ammonium chloride, two intervals of change in the specific output flux are noted at a fixed transmembrane pressure and experiment time. The first period occurs at a current density of 12.82 to 15.38 A/m
2
and is associated with penetration of the solvent with slight gas formation at the electrodes. The second period is observed from 15.38 to 25.64 A/m
2
and is associated with membrane degradation and intense gas formation, especially chlorine. It is noted that in the intermembrane channels the migration of cations and anions is affected by the processes of throttling, heat release, when operating in the limiting mode (when the current carriers H
+
and OH
–
appear), which is confirmed by the data of studies of the electrochemical parameters of the membrane system.
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