Preparation and Study of the Properties of Aluminum Powders, Suitable for the Manufacture of Powder Electrodes

2020 ◽  
Vol 839 ◽  
pp. 172-177
Author(s):  
Rashit A. Latypov ◽  
Evgeniy V. Ageev ◽  
Evgeniy P. Novikov
Keyword(s):  
Elemental Composition ◽  
Spherical Shape ◽  
Pulse Frequency ◽  
Powder Materials ◽  
Distilled Water ◽  
Electrical Parameters ◽  
Aluminum Powders ◽  
Wide Range ◽  
Powder Particles ◽  
Regular Spherical Shape

The results of the study of the shape, morphology and elemental composition of aluminum powder particles obtained in distilled water with the following electrical parameters of the electroerosive dispersion unit are presented: the capacity of discharge capacitors is 65 μF, voltage 100 V, pulse frequency 50 Hz. It is established that the powder consists of particles of regular spherical shape (or elliptical), irregular shape (conglomerates) and fragmentation, and the main elements of the powder are aluminum and oxygen. The obtained powder materials can be used for the manufacture of powder electrodes used in welding and surfacing of a wide range of parts.

scholarly journals MORPHOLOGY AND ELEMENT COMPOSITION POWDER ALLOY POWDER VNZH-95, OBTAINED BY ELECTROEROSION DISPERSION IN KEROSIN

2020 ◽  
pp. 15-20
Author(s):  
E. V. Ageev ◽  
N. M. Khoriakova ◽  
K. V. Sadova
Keyword(s):  
Elemental Composition ◽  
Alloy Powder ◽  
Spherical Shape ◽  
Working Fluid ◽  
Residence Permit ◽  
Nickel Iron ◽  
The Russian Federation ◽  
Biological Protection ◽  
Regular Spherical Shape ◽  
Electroerosion Dispersion

Residence permits pseudo-alloys are used for the manufacture of cylinder parts, bushings, complex-shaped blanks with curved surfaces: gyroscope rotors, inertial masses, erosion-resistant electrodes, funnel for cumulative charges, biological protection from gamma radiation. Recycling of tungsten pseudo-alloys residence permit is relevant and necessary due to the shortage of tungsten. A promising method of processing waste into fine powders is the method of electroerosive dispersion (EED) that we have chosen. The purpose of the work is to study the morphology and elemental composition of the powder of the VNZh-95 pseudo-alloy obtained by electroerosive dispersion in kerosene. In order to process the waste of the W-Ni-Fe alloy into powder, we used waste in the form of chips from the core of the VNZh-95 pseudo-alloy (Ni ̶ 3.2-3.7, Fe ̶ 1.5-2.0, W ̶ the rest). Kerosene is used as a working fluid. The EED process was carried out on the installation for obtaining powders from conductive materials (patent for the invention of the Russian Federation No. 2449859). The process was carried out at a voltage on the electrodes of 100 ... 110 V, the capacitance of the discharge capacitors 50 μF and a pulse repetition rate of 120 ... 130 Hz. The microstructure of the samples (along the transverse section) was studied using a Quanta 200 3D electron-ion scanning microscope. The powder obtained by the EED method for waste of VNZh-95 alloy in kerosene consists of particles of regular spherical shape (or elliptical) and irregular shape (conglomerates). Microanalysis of particles of electroerosive powder of pseudo-alloy VNZh-95 was carried out using an EDAX energy-dispersive x-ray analyzer built into the Quanta 200 3D scanning electron microscope. As a result of studying the elemental composition of the VNZh-95 pseudo-alloy powder obtained by EED in kerosene, it was found that the main elements are tungsten, nickel, iron, carbon and oxygen.

scholarly journals STUDY PARTICLE SIZE DISTRIBUTION OF ERODING POWDER LEAD BRONZES OBTAINED IN DISTILLED WATER

2018 ◽  
Vol 22 (4) ◽  
pp. 42-49
Author(s):  
E. V. Ageev ◽  
A. S. Pereverzev ◽  
A. S. Osminina ◽  
I. Yu. Grigorov
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Discharge Zone ◽  
Powder Materials ◽  
Average Particle ◽  
Distilled Water ◽  
Powder Particles ◽  
Local Exposure ◽  
Finely Dispersed Powder ◽  
Powder Lead

The article is devoted to the current problem of processing waste of conductive materials, in particular lead bronze, which accumulates in large quantities at enterprises. A promising method for processing any conductive material, characterized by wastelessness, ecological purity of the process, and low energy costs, is the method of electroerosive dispersion. The essence of the method of electroerosive dispersion is the destruction of current-conducting material as a result of local exposure to short-term electrical discharges between the electrodes. In the discharge zone, under high temperatures, heating, melting and partial evaporation of the material occurs, resulting in the formation of finely dispersed powder particles. At the same time, the electrical parameters of the installation will affect the productivity of the process for obtaining powder materials: the voltage at the electrodes, the capacitance of the discharge capacitors, and the repetition rate. The article presents the results of the analysis of particles of powdered lead bronze obtained by the method of electroerosive dispersion in distilled water from wastes, using the laser analyzer of particle sizes "Analysette 22 NanoTec". It has been experimentally established that the average particle size of powdered lead bronze is 9.73 μm, the arithmetic value is 9.731 μm. It was also found that the elongation coefficient (elongation) of particles with a size of 7.188 μm is 1.50.

scholarly journals Determination of the conductivity of non-metallic powder materials by the eddy current method

2019 ◽  
Vol 27 (1) ◽  
pp. 63-70
Author(s):  
V. S. Khandetskyi
Keyword(s):  
Eddy Current ◽  
Spherical Shape ◽  
Current Method ◽  
Solid Material ◽  
Powder Materials ◽  
Cylindrical Shape ◽  
Eddy Current Method ◽  
Sensor Field ◽  
Powder Density ◽  
Powder Particles

A theoretical analysis of the interaction of the eddy current sensor field with powder particles makes it possible to calculate the particle conductivity using the measured value of the sensor added active resistance. Relative to its own reactance, the value of this resistance is proportional to powder density, frequency of the probing field, electrical conductivity of particles and square of their diameter. Particles of spherical shape and cylindrical shape, the height of which is equal to the diameter of the base, are considered. The analysis allows to explain the experimentally observed different character of the resistance frequency dependences for powder and corresponding solid material when measuring by the same sensor.

scholarly journals An Evaluation of Morphological Changes and Deformability of Suspended Red Blood Cells Prepared Using Whole Blood with Different Hemoglobin Levels of Tibetans

2021 ◽  
pp. 1-10
Author(s):  
Rui Zhong ◽  
Dingding Han ◽  
Xiaodong Wu ◽  
Hong Wang ◽  
Wanjing Li ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Whole Blood ◽  
Blood Cells ◽  
Morphological Changes ◽  
Osmotic Fragility ◽  
Spherical Shape ◽  
Hypoxic Environment ◽  
Wide Range ◽  
Group A ◽  
Cell Membrane Protein

Background: The hypoxic environment stimulates the human body to increase the levels of hemoglobin (HGB) and hematocrit and the number of red blood cells. Such enhancements have individual differences, leading to a wide range of HGB in Tibetans’ whole blood (WB). Study Design: WB of male Tibetans was divided into 3 groups according to different HGB (i.e., A: >120 but ≤185 g/L, B: >185 but ≤210 g/L, and C: >210 g/L). Suspended red blood cells (SRBC) processed by collected WB and stored in standard conditions were examined aseptically on days 1, 14, 21, and 35 after storage. The routine biochemical indexes, deformability, cell morphology, and membrane proteins were tested. Results: Mean corpuscular volume, adenosine triphosphate, pH, and deformability were not different in group A vs. those in storage (p > 0.05). The increased rate of irreversible morphology of red blood cells was different among the 3 groups, but there was no difference in the percentage of red blood cells with an irreversible morphology after 35 days of storage. Group C performed better in terms of osmotic fragility and showed a lower rigid index than group A. Furthermore, SDS-PAGE revealed similar cross-linking degrees of cell membrane protein but the band 3 protein of group C seemed to experience weaker clustering than that of group A as detected by Western Blot analysis after 35 days of storage. Conclusions: There was no difference in deformability or morphological changes in the 3 groups over the 35 days of storage. High HGB levels of plateau SRBC did not accelerate the RBC change from a biconcave disc into a spherical shape and it did not cause a reduction in deformability during 35 days of preservation in bank conditions.

Pulsatile secretion of progesterone from the human corpus luteum: poor correlation with bioactive LH pulses

1986 ◽  
Vol 111 (4) ◽  
pp. 553-557 ◽  
Author(s):  
Inese Z. Beitins ◽  
Maria L. Dufau
Keyword(s):  
Corpus Luteum ◽  
Temporal Relationship ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Biologically Active ◽  
Poor Correlation ◽  
Serum Progesterone ◽  
Progesterone Secretion ◽  
Wide Range ◽  
Human Corpus Luteum

Abstract. Having previously established that biologically active luteinizing hormone (LH) is secreted in episodic pulsations that vary in relation to the menstrual cycle, we investigated the possibility that a temporal relationship could exist between the bioactive LH pulses and progesterone secretion from the late corpus luteum. In 4 young women blood was withdrawn every 15 min for 8 h. Serum progesterone concentrations fluctuated at a mean frequency of 0.9 h with a wide range of amplitudes (13.8 to 1.7 ng/ml). Serum bioactive LH pulse frequency in contrast was 0.25 pulses/h in all subjects. The pulse amplitude was 18.2 to 12.4 mIU/ml (2nd IRP-hMG). These data reveal that within the 8 h-period studied, progesterone secretory pulses occurred four times more frequently as those for bioactive LH. Therefore it is unlikely that a temporal relationship exists between individual bioactive LH and pulses of progesterone secreted by the late corpus luteum.

Qualitative assessment of air pollution in the working area of energy-intensive materials production by nanoscale aerosols with a solid dispersed phase

2021 ◽  
Vol 61 (12) ◽  
pp. 828-832
Author(s):  
Boris N. Filatov ◽  
Natalya I. Latyshevskaya ◽  
Natalya V. Krylova ◽  
Irina K. Gorkina ◽  
Yulya I. Velikorodnaya ◽  
...  
Keyword(s):  
Air Pollution ◽  
Mass Concentration ◽  
Solid Phase ◽  
Qualitative Assessment ◽  
Dust Particles ◽  
Dispersed Phase ◽  
Forced Circulation ◽  
Aluminum Powders ◽  
Nanoscale Particles ◽  
Wide Range

The presence of grinding, mixing, and fractionation of solid components of formulations leads to the formation of aerosols in the air of the working area with a wide range of dispersion of the solid phase - all this characterizes the organization of technological processes for the production of energy-intensive materials. The study aims to give a qualitative assessment of possible air pollution of the working area of energy-intensive materials production by nanoscale aerosols with a solid dispersed phase. The researchers carried out the sampling of the working area air and flushes from solid horizontal surfaces to produce energy-intensive materials. We carried out the sampling by forced circulation of the test air through the absorption devices of Polezhaev. Scientists used Triton TX-114 solution with a mass concentration of 2.0 mg/dm3 as an absorption medium. The researchers performed flushing from surfaces using cloth tampons moistened with Triton TX-114 solution with a mass concentration of 2.0 mg/dm3. We determined the particle sizes in the samples using NanotracULTRA (Microtrac). Scientists found aluminum and nitrocellulose particles with sizes from 36 to 102 nm in the air of the working area and flushes from horizontal surfaces. The study of the fractional composition of RDX and aluminum powders of the ASD-1 brand showed the presence of nanoscale particles in them. Nanoscale dust particles pollute the air of the working area and solid horizontal surfaces at certain stages of the production of energy-intensive materials. There are nanoscale particles in the composition of powders of some standard components of formulations. Flushes from solid horizontal surfaces are an adequate qualitative indicator of the presence of nanoaerosols in the air of the working area.

scholarly journals Preparation of microencapsulated PCMs for energy saving and thermal comfort of buildings

2021 ◽  
Vol 23 (09) ◽  
pp. 277-287
Author(s):  
Ashraf Mohamed Heniegal ◽  
◽  
Omar Mohamed Omar Ibrahim ◽  
Nour Bassim Frahat ◽  
Mohamed Amin ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Chemical Interaction ◽  
Spherical Shape ◽  
Building Envelope ◽  
Scanning Calorimetry ◽  
Indoor Temperature ◽  
New Techniques ◽  
Consumption Energy ◽  
Local Materials ◽  
Regular Spherical Shape

Energy improvement techniques for buildings are among the modern studies that concentrate on new techniques and methods of saving energy and improving the thermal performance in buildings. This research aims to prepare microencapsulated-PCMs (micro-PCMs) by using local materials and studied the influence of using micro-PCMs on thermal performance improvement and PCMs leakage problems improvement. The micro-PCMs of paraffin wax were prepared as the core PCMs materials while the melamine-formaldehyde polymer as the shell. The micro-PCMs were characterized through scanning electron-microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Analysis results showed the prepared micro-PCMs present a regular spherical shape and confirm that the formation composite of the shell effectively encapsulated the cores. Furthermore, the absence of chemical interaction between the MF and the PW components. The micro-PCM have potential for architectural applications in the building-envelope to store thermal energy, provide indoor-temperature at the comfortable range, and reduce the consumption energy in buildings.

scholarly journals Influence of parameters of impulse laser impact on the formation of the gradient of the structure of porous titanium powder

2018 ◽  
pp. 88-94
Author(s):  
D. V. Minko
Keyword(s):  
Laser Radiation ◽  
Titanium Powder ◽  
Structural Characteristics ◽  
Selective Laser Sintering ◽  
Light Flux ◽  
Laser Action ◽  
Pulsed Laser ◽  
Powder Materials ◽  
Solid Core ◽  
Powder Particles

The possibility of selective laser sintering of graded porous and compactly porous structures by surface fusion of powder particles is demonstrated while maintaining a solid core, which leads to the formation of interparticle contacts in the presence of a liquid phase. The interaction of the light flux of the laser pulse with the surface of the powder particles under multiple reflection is considered. It is shown that the effect of single pulses of laser radiation leads to the formation of sintered structural elements of a powder material having a diameter approximately equal to the diameter of the focal spot. Technological regimes of pulsed laser action are established at which steady contact formation of titanium powder particles of the fractional compositions under study occurs. The possibility of obtaining powder materials with a gradient structure by controlling the parameters of pulsed laser action is experimentally demonstrated. It was found that accurate dosing of thermal energy and the number of pulses of laser radiation makes it possible to minimize shrinkage of powder layers in the absence of particle conglomeration, to control the structural characteristics and properties of products, to preserve the microstructure and phase composition of the initial materials.

scholarly journals Evaluation of morphological parameters and bioactive compounds in different varieties of beetroot (Beta vulgaris L. ssp. esculenta GURKE var. rubra L.)

2015 ◽  
Vol 21 (3-4) ◽  
Author(s):  
T. Rubóczki ◽  
V. Raczkó ◽  
M. Takácsné Hájos
Keyword(s):  
Manufacturing Industry ◽  
Spherical Shape ◽  
Close Correlation ◽  
Quality Parameters ◽  
Water Soluble ◽  
Soluble Solids ◽  
Fresh Market ◽  
Mona Lisa ◽  
Solids Content ◽  
Regular Spherical Shape

Beetroot consumption based on pickled beets generally in Hungary which is due to the higher yield from second crop harvested in autumn and processed by manufacturing industry. Researches of the past years confirmed its favourable nutritional-physiological effects on human body so demands, as for fresh salad, also increased. The trial aimed at testing the interaction of varieties on quality parameters and in the same time suggestions are made how to use different varieties of beetroot according to its quality. Morphological and sensory evaluations were examined on 10 varieties of beetroot harvested in autumn. The regular spherical shape can reduce the refining loss during the processing of beetroot which is beneficial for the manufacturing industry. In our trial the root shape of Libero, Mona Lisa and Rubin varieties approached most the regular spherical shape (diameter/length – 1.0) which is favoured by not only processing industry but also fresh market. The highest red pigment content (betanin) was observed in Mona Lisa, Akela and Cylindra (34.58–47.66 mg/100 g). A similar trend could be observed in yellow pigments (vulgaxanthins) which proves the close correlation between the quantities of the two pigments (r=0.898). Highest total polyphenol (77.13–83.37 mg GAE/100g) and flavonoid (21.73–22.73 mg CE/100g) contents were detected in Akela, Mona Lisa and Bonel. These varieties are favourable for fresh salad and they can satisfy processing requirements also. Highest water soluble solids content was found in Akela (7.15%). In our conditions nitrate (NO3-N) values below 900 mg/kg were examined in all of the varieties which is favourable in the case of beetroot.

Structure and Properties of Modifier for Heat Transfer Printing on Cotton Fabric

2011 ◽  
Vol 331 ◽  
pp. 426-429
Author(s):  
Yi Mu ◽  
Lan Wang ◽  
Ming Hua Wu ◽  
Jun Xiong Lin
Keyword(s):  
Heat Transfer ◽  
Spherical Shape ◽  
Decomposition Temperature ◽  
Polymerization Process ◽  
Structure And Properties ◽  
Transfer Printing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Regular Spherical Shape

Modifier for heat transfer printing on cotton fabrics was prepared by semi-continuous emulsion polymerization process with butyl acrylate (BA), styrene (St), acrylonitrile (AN) and cross-linking monomer. FT-IR characterization of modifier groups showed that individual monomer well carried out polymerization. Transmission electron microscopy (TEM) photos demonstrated that latex particles had regular spherical shape and uniform distribution. TGA curves indicated that thermal decomposition temperature of modifier was 439 oC. As for the transfer printing products had good colour fastness, high transfer rate and no formaldehyde.

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