scholarly journals Вплив промислових очищувальних рідин на анодно-окисне захисно-декоративне покриття отримане у розчині хромового ангідриду

2021 ◽  
pp. 117-124
Author(s):  
Олексій Денисович Попов ◽  
Анатолій Іванович Долматов ◽  
Володимир Федорович Сорокін
Keyword(s):  
Oxide Coating ◽  
Operating Conditions ◽  
Water Soluble ◽  
Chemical Compositions ◽  
Operating Pressure ◽  
Washing Machine ◽  
Technological Parameters ◽  
The Stability ◽  
The Impact

The subject of research in this article is the anode-oxide coating of aluminum parts of the hull type of aircraft engine units and aircraft units under the influence of cleaning fluids of different nature and chemical compositions. The purpose of this work is to experimentally test, the effect of different cleaning fluids, under different operating conditions and on different equipment for the stability of the anode-oxide protective coating. Many experiments have been performed on three types of washing machines: jet and immersion washing machine, which works on all types of water-soluble detergents, washing machine cleaning in vacuum or low-pressure environment, uses modified alcohols or hydrocarbon solvents as a washing liquid, and specialized stand for cleaning parts with aviation kerosene, aviation fuel TS-1 or jet A-1. Flushing modes were, covered throughout the range of operation of this equipment. The operating conditions of engines and units and the need to use an anode-oxide coating of parts are determined. The main types of liquids for washing parts are considered. For each of the experiments a special technology of these studies was determined, as technological parameters, parameters that can change and affect the stability of the coating, were set the following temperature, detergent concentration, operating time, operating pressure in the detergent supply system. The change of each of these parameters was, carried out with the fixation of other technological parameters to determine the direct indicators of the impact of each of the parameters and to establish the growth of their impact on the anode-oxide coating. The conditions under which the coating is destroyed and the percentage of its damage from the total surface of the part are determined, and the quality of cleaning the part by particle size distribution and visual method was, also determined. It is determined that the greatest negative effects on the anodic oxide coating in the solution of chromic anhydride are acidic and alkaline water-soluble pore cleaning liquids, so they have the best quality of cleaning from contaminants, for which a range of indicators is determined at which the coating does not deteriorate.

The Effect of Technological Parameters on the Quality of UHMWPE Products

2013 ◽  
Vol 752 ◽  
pp. 233-240
Author(s):  
Imre Kállai
Keyword(s):  
Life Span ◽  
Research Work ◽  
Heavy Duty ◽  
Technological Parameters ◽  
Quality Properties ◽  
Joint Implants ◽  
The Stability ◽  
The Many ◽  
The Impact

We can encounter products made from UHMWPE in many different areas of utilization. This material is used in plastic bearings, ball-and-socket joints, heavy-duty plastic cog-wheels and joint implants. The UHMWPE is a very particular polymer, the special characteristics of which can be attributed to its molecular structure. The ulra-high molecular weight has an effect on wear-resistance, creep-resistance and hardness. These are the parameters demanded by the highly specialized utilization. On the other hand, this molecular stucture also has disadvantages next to the many advantages. Its greatest disadvantage is that it’s difficult to process. The UHMWPE is a thermoplastic, but because of the long molecular chains its injection molding is impossible. In the course of the present research work we will compare the mechanical and quality properties of products made with lathe machining (RAM extrusion) and direct compression molding. We will examine the impact of the changes of the manufacturing and technological parameters. We will be placing a special emphasis on the surface quality because the quality and life-span of the abovementioned products (bearings, ball-and-socket joints, artficial joints) largely depends on this parameter. Besides this we will examine the changes of hardness and the stability of size. In view of these results we will try to determine what would be the best manufacturing technology that could ensure the maximum performance and life-span of these products. [1,3,6] We are focusing by having the results, to optimizing the manufacturing.

Numerical Investigation of the Solidity Effect on Linear Compressor Cascades

2014 ◽  
Author(s):  
J. Sans ◽  
M. Resmini ◽  
J.-F. Brouckaert ◽  
S. Hiernaux
Keyword(s):  
Numerical Investigation ◽  
State Of The Art ◽  
Leading Edge ◽  
Operating Conditions ◽  
Compressor Cascade ◽  
Minimum Loss ◽  
Low Speed ◽  
High Mach ◽  
The Stability ◽  
The Impact

Solidity in compressors is defined as the ratio of the aerodynamic chord over the peripheral distance between two adjacent blades, the pitch. This parameter is simply the inverse of the pitch-to-chord ratio generally used in turbines. Solidity must be selected at the earliest design phase, i.e. at the level of the meridional design and represents a crucial step in the whole design process. Most of the existing studies on this topic rely on low-speed compressor cascade correlations from Carter or Lieblein. The aim of this work is to update those correlations for state-of-the-art controlled diffusion blades, and extend their application to high Mach number flow regimes more typical of modern compressors. Another objective is also to improve the physical understanding of the solidity effect on compressor performance and stability. A numerical investigation has been performed using the commercial software FINE/Turbo. Two different blade profiles were selected and investigated in the compressible flow regime as an extension to the low-speed data on which the correlations are based. The first cascade uses a standard double circular arc profile, extensively referenced in the literature, while the second configuration uses a state-of-the-art CDB, representative of low pressure compressor stator mid-span profile. Both profiles have been designed with the same inlet and outlet metal angles and the same maximum thickness but the camber and thickness distributions, the stagger angle and the leading edge geometry of the CDB have been optimized. The determination of minimum loss, optimum incidence and deviation is addressed and compared with existing correlations for both configurations and various Mach numbers that have been selected in order to match typical booster stall and choke operating conditions. The emphasis is set on the minimum loss performance at mid-span. The impact of the solidity on the operating range and the stability of the cascade are also studied.

scholarly journals Intensifications of the wooling mechanism with increasing electric conductivity of fibers

Academia Open ◽  
2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Khasanov Doston
Keyword(s):  
Mechanical Properties ◽  
Electric Conductivity ◽  
Quaternary Salt ◽  
Water Soluble ◽  
Technological Parameters ◽  
Protein Fiber ◽  
Effect Of The Composition

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 .

scholarly journals Assessment of vehicle brake control functional stability

2021 ◽  
Vol 12 (2) ◽  
pp. 33-44
Author(s):  
Volodymyr Volkov ◽  
◽  
Igor Gritsuk ◽  
Tetiana Volkova ◽  
Volodymyr Kuzhel ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Control Method ◽  
Operating Conditions ◽  
National Standards ◽  
Passenger Vehicles ◽  
The Difference ◽  
Braking Control ◽  
The Stability ◽  
Friction Surfaces

The article is devoted to the study of the influence of the brake control elements of passenger vehicles on the stability of their braking properties. The analysis of the influence of uneven braking forces on the wheels of one axle of vehicles on the deviation of the distribution of braking forces between the axles from its calculated value is carried out. When assessing the error in regulating the distribution of braking forces between the axles of vehicles, three components were taken into account: the theoretical error due to the imperfection of the selected control method (the difference between the actual calculated control characteristic from the ideal), the error created due to the instability of the ratio of the braking forces on the front and rear wheels, an additional error caused by the unevenness of the braking forces on the wheels of individual axles, since the fulfillment of the most stringent requirements of international and national standards for the efficiency of braking of vehicles and is inextricably linked with the need to increase the energy consumption of brake mechanisms. The energy consumption of braking mechanisms is understood as the ability of the latter to dissipate the greatest amount of energy of the braking machine without reducing the braking efficiency indicators to the minimum permissible level. Excessive heating of the braking mechanisms leads to a decrease in the friction coefficient μ of the friction surfaces and increased wear of the friction linings, and the brakes are the most unstable element of the braking control, which ensures the absorption and dissipation of the vehicle's energy during braking. The instability of the braking torques on the front and rear wheels, caused by a change in the coefficients of friction of friction pairs, leads not only to a change in the distribution of braking forces between the axles and individual wheels, but also to a decrease in the braking efficiency of vehicles under operating conditions. A method is proposed that makes it possible to assess the quality of regulation of the distribution of braking forces between the axles of a car, taking into account the instability of the braking forces on the wheels.

scholarly journals Problems of Analyzing Microstructure Images in Assessing the Impact of Technological Parameters of Combined Strain Wave Hardening on the Quality of the Surface Layer

2019 ◽  
Author(s):  
Андрей Киричек ◽  
Andrey Kirichek ◽  
Дмитрий Соловьев ◽  
Dmitriy Solovyev ◽  
Александр Хандожко ◽  
...  
Keyword(s):  
Surface Layer ◽  
Thermal Treatment ◽  
Strain Wave ◽  
Technological Parameters ◽  
Steel Microstructure ◽  
Main Indicator ◽  
Metallographic Images ◽  
Surface Layer Quality ◽  
The Impact

The problems of analyzing metallographic images and the method of their solution using modern software for the analysis of metallographic images are described. There is given an analysis of microstructure images as the main indicator of the surface layer quality by the example of studying the research results of strain wave hardening combinations and chemical-thermal treatment, in particular the influence of previous strain wave hardening and subsequent thermal and chemical- thermal treatment on the alloy steel microstructure or previous thermal and chemical- thermal treatment and subsequent strain wave hardening. On the basis of the analysis the effectiveness of strain wave hardening and chemical and thermal treatment is established.

scholarly journals Influence of soluble content losses on the ability of aerobic fungi to improve the nutritional content of pre-treated forages

2020 ◽  
Vol 47 (3) ◽  
pp. 298-308
Author(s):  
K. R. Idowu ◽  
A. S. Chaudhry ◽  
J. Dolfing ◽  
V. O. A. Ojo
Keyword(s):  
Secondary Metabolites ◽  
Growth Conditions ◽  
Water Soluble ◽  
Optimal Conditions ◽  
Similar Reduction ◽  
Filtering Method ◽  
Nutritive Quality ◽  
Andropogon Gayanus ◽  
The Impact

Fungal improvement of the nutritive content of low-quality forages can be affected by several factors among which loss of water-soluble content (WSC) plays a major role. To achieve this aim, two growth conditions i.e. forage-liquid ratios (1:3 and 1:5) and two inoculation times (14 and 28 days) were used to cultivate the selected fungi i.e. Pleurotus ostreatus (PO) at 30°C and Ceriporiopsis rivulosus (CR) at 20°C on Brachiaria decumbens (BD), Andropogon gayanus (AG), Triticum aestivum (TA) straw, Lolium perenne (LP), respectively with the view of selecting the optimal conditions that facilitate the release of WSC. The impact that losses of WSC have on the ability of fungi to improve the nutritive content (i.e. proximate, fibre, secondary metabolites and total antioxidant content) of the forages were then measured using 2 filtering methods i.e. light pump filtering method (LFM) and free flow filtering method (FFM). The optimal conditions that supported increased th soluble was identified as 28th day for both fungi; forage-liquid ratio of 1:5 for both fungi in most of the forages except BD (CR) and BD & AG (PO). The LFM led to lesser or no improvement in the nutritive quality of the upgraded forages while the opposite was recorded with the LFM. The LFM as against the FFM produced upgraded forages with lesser reduction in NDF; similar or higher ADF and lignin contents; and similar reduction in secondary metabolites and TAC when compared with un-improved forages. It can be concluded that the fungal improvement of the nutritive content of low-quality forages was negatively affected by the loss of WSC. It is therefore recommended that fungal improvement of the nutritive quality of low quality forages should be carried out with methods or techniques that facilitates little or no WSC loss in the upgraded forages.

Contrasting signatures of the sources and types of aerosols in the western and eastern Himalayas: Radiative implications

2021 ◽  
Author(s):  
Arun Bs ◽  
Mukunda Gogoi ◽  
Prashant Hegde ◽  
Suresh Babu
Keyword(s):  
Mineral Dust ◽  
Water Soluble ◽  
The Other ◽  
Anthropogenic Source ◽  
Chemical Compositions ◽  
Eastern Himalayas ◽  
Chemical Aging ◽  
Other Hand ◽  
Secondary Formation ◽  
The Impact

<p>The rapid changes in the pattern of atmospheric warming over the Himalayas, along with severe degradation of Himalayan glaciers in recent years suggest the inevitability of accurate source characterization and quantification of the impact of aerosols on the Himalayan atmosphere and snow. In this regard, extensive study of the chemical compositions of aerosols at two distinct regions, Himansh (32.4<sup>ᴼ</sup>N, 77.6<sup>ᴼ</sup>E, ~ 4080 m a.s.l) and Lachung (27.4<sup>ᴼ</sup>N, 88.4<sup>ᴼ</sup>E, ~ 2700 m a.s.l), elucidates distinct signatures of the sources and types of aerosols prevailing over the western and eastern parts of Himalayas. The mass-mixing ratios of water-soluble (Na<sup>+</sup>, NH<sub>4</sub><sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Cl-, SO<sub>4</sub><sup>2-</sup>, NO<sub>3</sub><sup>-</sup>, MSA<sup>-</sup>, C<sub>2</sub>O<sub>4</sub><sup>2-</sup>), carbonaceous (EC, OC, WSOC) and selected elemental (Al, Fe, Cu, Cr, Ti) species depicted significant abundance of mineral dust aerosols (~ 67%), along with a significant contribution of carbonaceous aerosols (~ 9%) during summer to autumn (August-October) over the western Himalayan site. On the other hand, the eastern Himalayan site is found to be dominant of OC (~ 53% in winter) followed by SO<sub>4</sub><sup>2-</sup> (as high as 37% in spring) and EC (8-12%) during August to February. However, OC/EC and WSOC/OC ratios showed significantly higher values over both the sites (~ 12.5, and 0.56 at Himansh; ~ 5.7 and ~ 0.74 at Lachung) indicating the secondary formation of organic aerosols via chemical aging over both the sites. The enrichment factors estimated from the concentrations of trace elements over the western Himalayan site revealed the influence of anthropogenic source contribution from the regional hot-spots of Indo-Gangetic Plains, in addition to that of west Asia and the Middle East countries. On the other hand, the source apportionment of aerosols (based on positive matrix factorization - PMF model) over the eastern Himalayas demonstrated the biomass-burning aerosols (25.94%), secondary formation of aerosols via chemical aging (15.94%), vehicular and industrial emissions (20.54%), primary emission sources associated with mineral dust sources (22.28%) and aged secondary aerosols (15.31%) as the major sources of aerosols. Due to abundant anthropogenic source impacts at the eastern Himalayan site, the atmospheric forcing is most elevated in winter (13.4 ± 4.4 Wm<sup>-2</sup>), which is more than two times the average values seen at the western Himalayan region during the study period. The heavily polluted eastern part of the IGP is a potential anthropogenic source region contributing to the aerosol loading at the eastern Himalayas. These observations have far-reaching implications in view of the role of aerosols on regional radiative balance and their impact on snow/glacier coverage.</p>

Structural and functional analysis of reconnaissance and fire system and decomposition of its functions and subsystems

2021 ◽  
pp. 38-48
Author(s):  
O. Maistrenko ◽  
O. Karavanov ◽  
A. Shcherba
Keyword(s):  
Functional Analysis ◽  
Fire Damage ◽  
Expert Group ◽  
Expert Evaluation ◽  
Military Conflicts ◽  
Main Factors ◽  
The Stability ◽  
The Impact

It is established that the role of reconnaissance and fire systems in the implementation of enemy fire damage in military conflicts occurring at the beginning of the XXI century. Increased  to 75%. However, it was found that the effectiveness of these systems depends on the quality of their equipment. The main factors that are often not taken into account in the acquisition are the possibility, interoperability, stability of each element, the impact of elements on the stability of each other and the functioning of the RVS as a whole. The analysis of recent research and publications has shown that as of today, the approaches to determining the composition of reconnaissance fire systems taking into account these factors are not justified. Given the above, it was decided to conduct a structural and functional analysis of the reconnaissance fire system and the decomposition of its functions and subsystems. To this end, based on the method of cluster analysis, an algorithm for combining a set of tasks performed by reconnaissance and fire systems into groups has been developed and substantiated. The method of expert evaluation was used to obtain substantiated data on the implementation of such a merger. According to the proposed algorithm, the main tasks were first identified, which involve reconnaissance and fire systems. Subsequently, an expert group was formed and the coefficient of relative competence of each member of the expert group was determined. The experts were then asked to combine the identified tasks according to their characteristics into an arbitrary number of groups. After processing the opinions of experts, 10 characteristic groups were identified. Finally, the experts were asked to combine the obtained groups in such a way that each association consisted of similar objects and the objects of different associations differed significantly. The results of the work revealed the functional interconnectedness of the tasks, processes and subsystems of the reconnaissance and fire system. It is also established that a typical reconnaissance fire system will consist of three subsystems (control, reconnaissance and fire influence), which perform specific functions for each of them.

scholarly journals The comparison of single and double cut harvests on biomass yield, quality and biogas production of Miscanthus × giganteus

2019 ◽  
Vol 65 (No. 7) ◽  
pp. 369-376
Author(s):  
Marta Kupryś-Caruk ◽  
Sławomir Podlaski
Keyword(s):  
Dry Matter ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Lignin Content ◽  
Soluble Sugars ◽  
Water Soluble ◽  
Miscanthus Giganteus ◽  
Yield Quality ◽  
The Impact

The aim of the research was to determine the impact of double-cut harvest system on yield, as well as on suitability of Miscanthus × giganteus biomass for ensiling and biogas production. Biomass was harvested at the end of June (harvest I) and at the beginning of October (harvest II, regrowth). A single-cut regime at the end of October was also conducted. Biomass from harvests I and II was ensiled and subjected to anaerobic fermentation. The total dry matter (DM) yield from double-cut harvest system was similar to the DM yield from one-cut harvest, but two harvests per year had a positive effect on chemical composition of the biomass. C/N ratio and lignin content in the biomass from harvest I was lower compared to the single-cut biomass. Double harvest biomass was susceptible to ensiling, however, the biomass from harvest I characterized by low dry matter and water soluble sugars content resulted in poorer quality of the obtained silage (butyric acid was present). There were no significant differences between the methane yields obtained from ensiled biomass from harvests I and II.

scholarly journals Study of the Influence of Technological Parameters on Generating Flat Part with Cylindrical Features in 3D Printing with Resin Cured by Optical Processing

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1941
Author(s):  
Aurel Tulcan ◽  
Mircea Dorin Vasilescu ◽  
Liliana Tulcan
Keyword(s):  
3D Printing ◽  
Flat Surface ◽  
Coordinate Measuring Machine ◽  
3D Printer ◽  
Light Control ◽  
Technological Parameters ◽  
Optical Processing ◽  
Measuring Machine ◽  
The Impact

The objective of this paper is to determine how the supporting structure in the DLP 3D printing process has influences on the characteristics of the flat and cylindrical surfaces. The part is printed by using the Light Control Digital (LCD) 3D printer technology. A Coordinate Measuring Machine (CMM) with contact probes is used for measuring the physical characteristics of the printed part. Two types of experiment were chosen by the authors to be made. The first part takes into consideration the influence of the density of the generated supports, at the bottom of the printed body on the characteristics of the flat surface. In parallel, it is studying the impact of support density on the dimension and quality of the surface. In the second part of the experiment, the influence of the printed supports dimension on the flatness, straightness and roundness of the printed elements were examined. It can be observed that both the numerical and dimensional optimum zones of the support structure for a prismatic element could be determined, according to two experiments carried out and the processing of the resulting data. Based on standardized data of flatness, straightness and roundness, it is possible to put in accord the values determined by measurement within the limits of standardized values.

Sign in / Sign up

Export Citation Format

Share Document