The article shows the setting of boundary value problems in heat exchange unit when exposed caryopsis microwave field. Weevil is the uneven distribution of moisture by volume. We have also found a ...sequence of solutions of boundary value problems
A KPU-200 movable capacitor installation Maslov, V. V.; Rumyantsev, V. G.; Basmanov, V. F. ...
Instruments and experimental techniques (New York),
03/2014, Letnik:
57, Številka:
2
Journal Article
Recenzirano
A movable electrophysical capacitor installation with a 250-kJ maximum bank energy, which generates intense neutron pulses, is described. A current pulse generator with a capacitive energy storage ...forms the basis of the installation. When the initial voltage at the capacitor bank is up to 35 kV, the installation ensures a flow of current pulses with amplitudes of up to 2 MA in a gas-discharge plasma-focus chamber, which is filled with an equal-component deuterium-tritium (DT) mixture. Under these conditions, the chamber is capable of repeatedly generating single fast-neutron pulses with an energy of 14.1 MeV, a duration of ∼70 ns, and an integral yield over 1013 neutrons/pulse.
Biosensor devices that include hybrid nanostructures as transducer surface modifiers meet current requirements for methods of research and determination of drugs, including antidepressants. Here, we ...consider the features of amperometric monoamine oxidase biosensors based on screen-printed graphite electrodes modified with nanocomposite consisting of C
60
/cobalt nanoparticles/amino derivative of a second-generation polyether polyol/chitosan in the determination of the tricyclic antidepressant amitriptyline. The best modifier was selected using transmission electron microscopy, scanning electron microscopy, electrochemical impedance spectroscopy, and differential pulse voltammetry. In the biosensor development, the conditions for applying the composite based on cobalt nanoparticles/amino derivative of polyether polyol to the electrode surface were varied: electrochemical deposition, sequential deposition by the layer-on-layer method, and deposition of a mixture. As an analytical signal of the biosensor, we used the peak of the electrochemical oxidation of hydrogen peroxide, which is formed during the enzymatic oxidation of serotonin under the action of monoamine oxidase. The operating principle of the biosensor is based on the inhibitory effect of amitriptyline on the catalytic activity of immobilized monoamine oxidase. For the selected modifier, the determined concentration range of amitriptyline is 1 × 10
–4
–1 × 10
–8
mol/L and the lower limit of the determined contents is 5 × 10
–9
mol/L under optimal operating conditions. Comparison of the results of the amitriptyline determination in a pharmaceutical preparation and urine that were obtained using a monoamine oxidase biosensor and the method of fluorescence polarization immunoassay (dilution of the tracer of 1 : 32, dilution of antibodies of 1 : 128, range of working concentrations from 5 × 10
–8
to 5 × 10
–9
mol/L), which has proven itself in the determination of medicinal substances, confirmed the correctness of the developed method.
Acetylcholinesterase (ChE) sensor based on Prussian blue (PB) modified electrode was developed and tested for the detection of organophosphorus and carbamic pesticides. The signal of the sensor was ...generated in PB mediated oxidation of thiocholine recorded at+200 mv in DC mode. ChE from electric eel was immobilized by cross-linking with glutaraldehyde in the presence of bovine serum albumin (BSA) on the surface of screen-printed carbon electrode covered with PB and Nafion. The content of the surface layer (specific enzyme activity, Nafion and BSA amounts) was optimized to establish high and reliable response toward the substrate and ChE inhibitors. The ChE/PB sensor makes it possible to detect Aldicarb, Paraoxon and Parathion-Methyl with limits of detection 30, 10 and 5 ppb, respectively (incubation 10 min). The feasibility of practical application of the ChE/PB sensor developed for the monitoring of degradation of the pesticides in wine fermentation was shown. To diminish matrix interferences, the electrolysis of the grape juice with Al anode and evaporation of ethanol were suggested, however the procedures decrease the sensitivity of pesticide detection and stability of the sample tested.
An inorganic film of ruthenium hexachlororuthenate (RuRuCl
6
), deposited on the surface of a glassy carbon electrode, exhibits electrocatalytic activity in the oxidation of purine nucleosides, such ...as guanosine and adenosine. Appropriate operating conditions are found for fabricating a polymer film on the surface of glassy carbon and for recording the maximum electrocatalytic current for the modified electrode. A method for the selective voltammetric determination of guanosine and adenosine in their simultaneous presence at an electrode modified by a RuRuCl
6
film is developed. A procedure is proposed for the amperometric detection of purine nucleosides with this modified electrode under the conditions of flow-injection analysis. The linear dependence of the analytical signal on the concentration of guanosine and adenosine is observed up to 5 × 10
–6
M in the stationary mode and up to 5 × 10
–7
M in the flow system. The proposed method for the selective determination of guanosine and adenosine was tested in the analysis of human urine.
An amperometric biosensor based on a platinum screen-printed electrode and immobilized monoamine oxidase is developed to determine antidepressants of different classes. Petylyl, pyrazidol, and ...flu-oxetine can be determined with determination limits of 8 x 10 super(-9), 8 x 10 super(-7), and 8 x 10 super(-10) M, respectively. A procedure is proposed for determining fluoxetine in tablets. It is shown that petylyl can be selectively determined by an immunochemical technique using the developed biosensor and immobilized antibodies in the concentration range from 1 x 10 super(-4) to 1 x 10 super(-8) M.
The effect different types of bottom soil have on the acoustic signal produced by air bubbles passing through the soil into water is considered. The gas flux is calculated using data from recording ...of the acoustic signal produced by active bubbling methane seepages in Laspi Bay, allowing for the error introduced by the soil. The inconsistency in the intensity of the methane fluxes is demonstrated.
Surface modification of screen-printed graphite electrodes with nanostructured materials (multiwall carbon nanotubes, gold and silver nanoparticles) allow their application as supports of ...amperometric monoaminoxidase biosensors for the determination of antidepressant drugs (moclobemide, tianeptine, and amitriptyline). This approach improves analytical characteristics of the corresponding biosensors because of the inhibitory effect of antidepressants (two-parameter concerted inhibition) on the catalytic activity of an immobilized enzyme. The analytical capabilities of the developed biosensor types were compared. The range of working concentrations was from 5 × 10
–9
to 1 × 10
–4
M and the lower limit of the analytical range was of about 8 × 10
–10
M. Biosensors based on electrodes modified with nanostructured materials were tested in the control of the concentration of drugs in body fluids (urine) and dosage forms.
The article describes the technology of the supercomputer twin of a nuclear power plants, which describes the main circulation circuit of the coolant. The technology is based on a joint ...one-dimensional and three-dimensional description of a reactor expanding the field of application of traditional one-dimensional system codes for describing fundamentally three-dimensional processes in reactor plenum. A description of the technology and verification data based on experimental studies is provided. The application of this technology to the analysis of the partial operating modes of the RITM-200 reactor plant was demonstrated, which made it possible to mitigate power limitations when disconnecting part of the heat exchange surface of the steam generator, reduce the costs of repair of the reactor plant associated with the replacement of steam generator cassettes, and avoid prolonged shutdown of a nuclear icebreaker.
The properties of hexarhenium chalcogenide nanoclusters (K
4
{Re
6
S
8
}(OH)
6
·8H
2
O and K
4
{Re
6
S
8
}(CN)
6
·8H
2
O) in combination with carbon nanomaterials (carbon nanotubes and graphene ...oxide) are studied by voltammetry, electrochemical impedance spectroscopy, atomic force microscopy, and spectrophotometry and their screening is performed for use as hybrid modifiers of screen-printed graphite electrodes in immunosensors in order to improve analytical characteristics. The high negative charge of nanoclusters can be considered the driving force of the adsorption of clusters in the formation of electrodes modified by hybrid nanomaterials. It was found that hexarhenium chalcogenide nanoclusters possess electrochemical activity, which was first used to register immunochemical interactions. The change in the resistance of electron transfer made it possible to choose the best hybrid nanomaterials. The parameters of the surface roughness of the modified electrodes associated with the height properties of the irregularities were estimated. The use of hexarhenium chalcogenide nanoclusters in combination with carbon nanomaterials as hybrid nanomodifiers has made it possible to develop highly sensitive and selective amperometric and impedimetric immunosensors for the determination of tricyclic antidepressants (amitriptyline, desipramine, and imipramine) in pharmaceuticals and urine. The limit of quantification (LOQ) is at the level (4–7) × 10
–11
M. The relative standard deviation does not exceed 5%.
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