Parameters of a layer forming machine for flax processing

The paper considers the machines used for flax layer-thinning during its processing. The designs of the most widely used layer-thinning machines of Russian, Belarusian and foreign production in the linen industry are analyzed. As a result of the analysis, it was found that the machines of both Russian and Belarusian production have the principle of the thinning with a fixed layer, and some foreign ones with free fixation.

Extraction of Rare Earth Metals by Solid-Phase Extractants from Phosphoric Acid Solution

Nowadays, solving the problem of rational, integrated use of the mined raw materials, the transition to waste-free technologies for its processing is a crucial task. The sulfuric acid technology used for the processing of apatite concentrates on a large industrial scale does not provide the associated extraction of accompanying valuable components—rare earth metals (REM). During apatite concentrate processing, rare-earth metals are affected by the technology-related dispersion, being distributed between the insoluble leaching residue and phosphoric acid solution sent to the production of fertilizers. The necessity of a cost-effective method development for the extraction of rare earth metals is quite obvious already in connection with the indicated significance of the problem. Phosphoric acid solutions that simulate the composition of industrial phosphoric acid solutions of the following composition 4.5 mol/L H3PO4, 0.19 mol/L H2SO4 and 0.10–0.12% REM were selected as the object of research. The extraction of rare earth metals was carried out using polymers containing a fixed layer of an extractant—di-2-ethylhexylphosphoric acid (D2EHPA). Fixed layer was obtained by impregnation-saturation (solvent-impregnated resin (SIR)) or by the introduction of an extractant at the stage of polymer matrix synthesis (extractant-resin extraction (ERE)). The work determined the thermodynamic and technological characteristics of the solid-phase extraction of rare earth elements from phosphoric acid solutions with polymers impregnated with D2EHPA and containing a rigidly fixed extractant in a styrene-divinylbenzene resin matrix. The possibility of effective multiple use of polymeric resins containing D2EHPA, regenerated with a solution of 1 mol/L sodium citrate, was revealed.

A Study on the Tip-Based Nanomachining of Silicon Wafer Using Atomic Force Microscopy (AFM)

In this work, the principles of nanoindentation and nanoscratching processes (tip-based nanomachining processes) are applied in the computational study of relevant material behaviors of single crystalline silicon wafer. Molecular dynamics (MD) simulations are carried out to model the tip-based nanomachining process of a silicon substrate by employing LAMMPS, a free MD simulation software. A spherical diamond tool tip with a radius of 8Å is considered. In the MD simulation, a single diamond indenter is treated as a rigid body. The dimensions of the silicon workpiece in the MD simulations are 500Å × 500Å × 350Å, containing 2,207,698 Si atoms. A diamond cubic lattice structure is employed to arrange these Si atoms from the very beginning at 293 K (room temperature) and a lattice constant of 5.43Å is employed. The lowest layer of the Si workpiece model is fixed and this fixed layer is one atom thick i.e. its thickness is 5.43Å. Immediately above the fixed layer is another layer of equal thickness (5.43Å), which is called thermostat layer. This layer serves the purpose of maintaining constant temperature of the system. The force-controlled approach is employed for this study. Essentially, this research evaluates the influence of three parameters: exerted force on indenter, workpiece temperature (room temperature and several higher workpiece temperatures), and indenter size on the depth of indentation, length of scratch, and coordination number of the atoms. Verlet -Velocity algorithm is used to compute the velocities and positions of the atoms. Since we desired to maintain consistency in volume, energy, and the number of particles, the constant-energy ensemble (NVE), also known as microcanonical ensemble is applied in the simulations. Both the Si-Si and C-C interactions are computed using the Tersoff potential throughout the simulations while the Si-C interactions are computed with the Morse potential. The MDS results are visualized and analyzed using OVITO, a free and commonly use visualizing tool. It is found that these parameters (exerted force on indenter, operating temperature of the silicon substrate, and size of the indenter) have substantial influence on the behavior of the silicon substrate.

CULTIVATION OF CELLS 4647 AND THE PERSPECTIVE VIRUS IN THE ICELLIS NANO BIORACTOR

A technique was developed for culturing 4647 cells and smallpox vaccine on the iCELLis Nano bioreactor with a fixed layer of fixed microcarriers.

QUALITY OF NATURAL COFFEE AND PULPED IN THE FUNCTION OF TEMPERATURE ALTERNATION DURING MECHANICAL DRYING

The research evaluates the sensorial quality of processed and dried coffee beans in different ways. Two types of processing were performed: dry and wet; And seven drying methods: drying in the terrier, and mechanical drying with heated air at 50ºC until coffee reaches 30% water content, followed by drying with air heated to 35ºC until reaching 11% water content; drying in fixed-layer dryers with heated air at 45 ° C until the coffee reaches 30% water content, followed by drying with heated air at 35 ° C until reaching 11% water content; and drying in fixed layer dryers with heated air at 40 ° C until coffee reaches 30% water content, followed by drying with heated air at 35 ° C until reaching 11% water content; drying in fixed layer dryers with heated air at 35 ° C until the coffee reaches 30% water content, followed by drying with heated air at 50 ° C until reaching 11% water content; drying in fixed-layer dryers with heated air at 35 ° C until the coffee reaches 30% water content, followed by drying with heated air at 45 ° C until reaching 11% water content; drying in fixed-layer dryers with heated air at 35 ° C until the coffee reaches 30% water content, followed by drying with heated air at 40 ° C until reaching 11% water content. The mechanical drying system consisted of three dryers of fixed layer, allowing the control of temperature and drying flow. The cafes were tasted according to the evaluation system proposed by the American Specialty Coffee Association (SCAA). Analyzes of the physical-chemical composition and physiological quality of the grains were carried out, involving: acidity grease, potassium leaching, electrical conductivity, color and germination. The results show that the pulped coffee is more tolerant to drying than the natural coffee, regardless of how it was dried.