scholarly journals Studying of movement kinematics of dynamically active sieve

2019 ◽  
Vol 23 (1) ◽  
pp. 94-97 ◽  
Author(s):  
Dmitry Popolov ◽  
Sergey Shved ◽  
Igor Zaselskiy ◽  
Igor Pelykh

Abstract The article presents the movement kinematics of the modular bar element of a dynamically active polymer sieve of a vibrating screen. On the basis of analytical methods, the mathematical model was obtained, which makes it possible to determine the law and trajectory of the modular bar element movement depending on its geometric characteristics, physico-mechanical properties of the polymer material, the regime and technological parameters of the vibrating screen. The results of this research show that in the working frequency range of the vibrating screen grate, modular bar element of the dynamically active sieve moves along the trajectories, the envelope of which is represented by Cassini’s ovals, which along with the generation of the amplitude component in the horizontal and vertical directions allows one to obtain the selfcleaning effect of the sowing surface.

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3755
Author(s):  
Štefan Gašpár ◽  
Tomáš Coranič ◽  
Ján Majerník ◽  
Jozef Husár ◽  
Lucia Knapčíková ◽  
...  

The resulting quality of castings indicates the correlation of the design of the mold inlet system and the setting of technological parameters of casting. In this study, the influence of design solutions of the inlet system in a pressure mold on the properties of Al-Si castings was analyzed by computer modelling and subsequently verified experimentally. In the process of computer simulation, the design solutions of the inlet system, the mode of filling the mold depending on the formation of the casting and the homogeneity of the casting represented by the formation of shrinkages were assessed. In the experimental part, homogeneity was monitored by X-ray analysis by evaluating the integrity of the casting and the presence of pores. Mechanical properties such as permanent deformation and surface hardness of castings were determined experimentally, depending on the height of the inlet notch. The height of the inlet notch has been shown to be a key factor, significantly influencing the properties of the die-cast parts and influencing the speed and filling mode of the mold cavity. At the same time, a significant correlation between porosity and mechanical properties of castings is demonstrated. With the increasing share of porosity, the values of permanent deformation of castings increased. It is shown that the surface hardness of castings does not depend on the integrity of the castings but on the degree of subcooling of the melt in contact with the mold and the formation of a fine-grained structure in the peripheral zones of the casting.


2020 ◽  
Vol 17 ◽  
pp. 00094
Author(s):  
Dmitry N. Byshov ◽  
Irina A. Petunina ◽  
Elena A. Kotelevskaya ◽  
Sergey N. Borychev ◽  
Georgy K. Rembalovich

The paper presents a method to substantiate the technical and technological parameters of the device to sort corn cobs, which takes into account the biometric and physical-mechanical properties of the treated plant objects. The method of basic parameters substantiation involves determining the overall dimensions of the device, the geometric and technological parameters of the working bodies, as well as the energy for operation.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 616
Author(s):  
Ján Kruželák ◽  
Andrea Kvasničáková ◽  
Klaudia Hložeková ◽  
Rastislav Dosoudil ◽  
Marek Gořalík ◽  
...  

In the present work, composite materials were prepared by incorporation of manganese-zinc ferrite, carbon black and combination of ferrite and carbon black into acrylonitrile-butadiene rubber (NBR). For cross-linking of composites, standard sulfur-based curing system was applied. The main goal was to investigate the influence of the fillers on the physical-mechanical properties of composites. Then, the electromagnetic absorption shielding ability was investigated in the frequency range 1 MHz–3 GHz. The results revealed that composites filled with ferrite provide sufficient absorption shielding performance in the tested frequency range. On the other hand, ferrite behaves as an inactive filler and deteriorates the physical-mechanical characteristics of composites. Carbon black reinforces the rubber matrix and contributes to the improvement of physical-mechanical properties. However, composites filled with carbon black are not able to absorb electromagnetic radiation in the given frequency range. Finally, the combination of carbon black and ferrite resulted in the modification of both physical-mechanical characteristics and absorption shielding ability of hybrid composites.


2021 ◽  
Vol 890 ◽  
pp. 120-137
Author(s):  
Mihai Octavian Crăcănel ◽  
Eduard Laurențiu Niţu ◽  
Daniela Monica Iordache

The FSW process has proven to be a promising process for joining steels and improving their characteristics. However, the use of wrongs technological parameters leads to the appearance of defects. In this study, the macro and microstructural characteristics of steel joints and their mechanical properties are analyzed, and the main types of defects of the butt steel joints are presented. The main conclusions of the works studied are summarized and the main development directions for research on the characterization of steel structures joined by the FSW process are identified.


2019 ◽  
pp. 7-8
Author(s):  
M. M. Egorov ◽  
V. I. Milov ◽  
M. K. Timin ◽  
T. P. Mukhina ◽  
V. S. Smirnov ◽  
...  

The effect of pressure, temperature and time during direct pressing on the strength and optical characteristics of adhesive plasticized polyvinyl butyral films is studied. A mathematical analysis of the results of a full factorial experiment is carried out and the regression equations are derived.


2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.


Academia Open ◽  
2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Khasanov Doston

The wide possibilities of modifying manufactured industrial fibers aimed at improving their physico-mechanical properties, structural and technological parameters. In connection with the above, it was of interest to study the effect of a number of water-soluble compositions based on a poly-quaternary salt of dimethyl-allyl-β - methacryloyloxyethylammonium bromide in combination with glycerin on the structural and physico-mechanical properties of protein fiber, and also to study the effect of the composition on wool spinning and the quality of wool yarn .


2020 ◽  
Vol 8 (6) ◽  
pp. 2565-2570

Today, the production of knitwear is developing at a faster pace. In industry, trade and the service sector, the production of knitwear, combining high technology and low cost, with good consumer properties is urgently required. Consumers today are looking for comfort, fashion and style, which results in ever-changing demands on the apparel market. As the consumer’s requirements to quality and appearance of product are daily increasing, the attention to the question of replacement of a smooth cloth on wide assortment with pattern effect is sharply brought. This work deals with the analysis of technological parameters and physical-mechanical properties of the knit fabric with pattern effect. With the aim of to expand the assortments of knitwear and to use the technological capabilities of double-bed flat knitting machines in fullest extent possible, on the base of rib structure, by using of loop transference 2 new variants of combined structure were developed and recommended. Samples differ from each other by the rapport and pattern effect of the knit structure. Technological parameters, such as loop length, stitch density, surface and volume density, physical-mechanical properties, such as breaking strength and elongation of newly developed combined knit structures were also determined by experimental method. Loop length and stitch density are important variables, that by changing them, the surface and volume density can be changed, that can manage the raw material consumption and determine the quality of knit fabrics. Breaking strength and elongation are important and decisive parameters for end uses since low strength properties shorten the useful life time as well disable the functionality of these products. Patterns of influence of structural elements, such as transferred loops on the surface density and volume density of knitwear was established. It is found that offered structures have some advantages to compare to basic structure. On the aim of resource economy technology, they give a possibility of raw material expenditure decreasing 22-47%.


2010 ◽  
Vol 2 (1) ◽  
pp. 117-121
Author(s):  
Darius Plonis

An algorithm and program in MATLAB® for the dispersions characteristics calculation in wide frequency range 15–100 GHz was created. We calculated and analyzed in ferrite and semiconductor waveguides, then they are longitudinally magnetized, also we analyzed main mode HE11 and higher modes EH11 and HE12 dispersion characteristics. We analyzed semiconductor p-Ge, p-GaAs waveguides and compared gyromagnetic and gyroelectric waveguides bandwidth with dielectrical layer. We decided that outer dielectrical layer changed waveguide working frequency range. We draw conclusion that it can be used for made microwave devices for example phase shifters or other devices.


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