The paper presents the developed design of a combined electric baromembrane apparatus for the separation, concentration, and purification of industrial solutions and effluents. The separation of the ...solution is implemented in two stages: at the first stage, the solution passes through a flat-chamber module; at the second stage — through a tubular module, providing a high degree of solution purification. In addition, a procedure for calculating the separation area, the volume of the separated solution in the flat-chamber and tubular modules, as well as the volume of collectors for cathode and anode permeates of the tubular module, was developed. Calculations of the average permeability along the length of the membrane and the total electric power consumption for the separation of galvanic process solutions containing salts of heavy metals were performed.
High-resolution X-ray techniques were applied to examine the effects of gold nanoparticles (size <5 nm) on natural pulmonary surfactant and pure DPPC monolayers preliminarily formed on water subphase ...in a Langmuir trough. Hydrophobic and hydrophilic nanoparticles were delivered from nanoaerosol using electrodeposition method. Grazing incidence diffraction, X-ray reflectivity, and X-ray standing wave measurements allow to monitor the changes in molecular organization of lipid monolayer and to locate the position of gold nanoparticles. X-ray experiments were performed over a period of 9-14 h. The obtained results evidenced that, on a long time scale, the deposition of nanoparticles, even at low doses, can induce pronounced alterations in lipid monolayer. The presented data can help to elucidate the mechanism of pulmonary translocation of inhaled nanoparticles that is of special interest for biomedical investigations of potential risk of nanoaerosols for human health.
The design of a flat-chamber electrobaromembrane apparatus for separating, concentrating, and purifying solutions and effluents in various industries has been updated. A distinctive feature of the ...updated design of the apparatus is cooling of the solution for separation in small separation chambers. A method has been developed to calculate the total volume of the solution being separated as well as the total volume of the apparatus body and its components, including the technological and design parameters of the cooling radiator, and to determine the mass of the structural materials for designing and constructing the apparatus. Comparative data showing the effectiveness of the developed design vis-à-vis the prototype is presented.
Individual polymer implants are widespread for bone reconstruction after decompressive craniectomy. Despite the availability of customized titanium products, various specialists and hospitals prefer ...polymer implants.
To compare the methods of modeling and manufacturing the polymethylmethacrylate implants and identify the features affecting the quality of reconstruction.
We analyzed 14 patients with extensive skull defects after installation of polymethyl methacrylate implants. Software used for modeling of individual implants by different specialists was compared.
Satisfactory reconstruction result was obtained in all cases. There were no infectious complications. The authors outlined certain important aspects for modeling of individual polymer products: local use of anatomical thickness of the implant, leaving safe spaces, prevention of temporal retraction, template-based resection before reconstruction.
To date, skull defect closure with polymeric materials remains relevant, and even has certain advantages over customized titanium products.
Abstract
Tall oil fatty acids are a by-product of the sulfate pulping of cellulose. The field of application of tall oil fatty acids is currently limited to the production of polyhydric alcohol ...esters (glycerol, etriol, and pentaerythritol, primarily, for the production of alkyds); ethanolamides; disproportionated and dimer acids (including amides based on them); imidazolines; salts; as well as lower alkyl esters. However, tall oil fatty acids have the potential to be used as a basis for the synthesis of motor oils and their additives, additives to diesel fuel, as well as raw materials for the production of biodiesel fuel.
In the present work, a new delivery and dispensing system for root crops is developed. This system prepares the vegetables for subsequent processing. The dependence of the system’s energy parameters ...and the rheological properties of the feed produced on the design parameters is established analytically.
The proposed rotary shredder for root vegetables yields a product meeting the nutritional requirements for animal feed, with minimal energy requirements, because of the low rotor speed and the ...optimal cutting positions around the drum. The parameters of the shredder are calculated and their influence on its performance is studied.
The paper considers the uncooled photodetectors based on GalnAsSb/GaAlAsSb heterostructures, which can be applied in precision diode laser spectroscopy. The spectral sensitivity range of ...photodetectors with a photosensitive area diameter of 1.0 mm and 2.0 mm is 1.0–2.4 μm
.
The current monochromatic sensitivity at the wavelength of 2.1 μm has a value of 1.0 A/W without bias. The capacity reaches 375 pF with a photosensitive area diameter of 1.0 mm and 800–5000 pF with 2 mm. The modern gas analyzers based on diode lasers and developed photodetectors for medical screening diagnostics by analyzing the gas compositions of exhaled air, for control of impurity gases in the process of rectification of inorganic hydrides, control of methane leaks in gas pipelines, as well as for registration of exhaust gases of a moving car are presented.
A method is proposed for optimizing the specific flow of a substance at the outlet of filtration membranes with limitations on current, electroosmotic permeability, retention coefficient, and current ...efficiency at a constant transmembrane pressure. Based on analytical and empirical studies, engineering formulas have been obtained making it possible to calculate the specific output flow for flat-chamber devices with OFAM-K and OPMN-P nanofiltration membranes, which determines the productivity of the electrochemical nanofiltration process of separation of zinc-containing solutions in wide ranges of changes in the electric current density, electrical permeability, and membrane retention coefficient, as well as in transmembrane pressure. The adequacy of the proposed method was verified by comparing calculated and experimental data on the specific flow of matter at the output of the OFAM-K anode membrane and the OPMN-P cathode one. The verification has shown the effectiveness of the obtained engineering formulas in a wide range of changes in the current density on the membranes.
An efficient design of the flat-chamber-type electrobaromembrane apparatus was developed and based on it a calculation method that allows to determine the total working area of the membranes, the ...useful area of the near-cathode, near-anode membranes and the volume of the solution to be separated per unit volume of the developed apparatus.
PDF
