energy parameter
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2021 ◽  
Vol 37 (6) ◽  
pp. 1287-1294
Author(s):  
Ioana Stanciu ◽  
Noureddine Ouerfelli

Mathematical models that describe the variation of soybean oil viscosity with temperature according to the recent WLF and VTF (or VFT) equations and traditionally by the Arrhenius equation. The Arrhenius equation shows that the viscosity of the oil is proportional to the absolute temperature and is determined by the activation energy parameter. In Arrhenius' equation the absolute temperature is replaced by T + b where both adjustable T and b are in ° C. The mathematical models described by the equations WLF and VTF, are equal to each other. All three equations are in the same model when used for experimental data of temperature-viscosity dependence, they give exactly the same very high regression coefficient.


MAUSAM ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 57-66
Author(s):  
FEIGE FEIGE ◽  
ZAHEER AHMADBABAR ◽  
SHENG LIGUO ◽  
XIEFEIZHI FEIZHI ◽  
YUNCHEN YUNCHEN ◽  
...  

Extreme weather events over Asia particularly in Pakistan are becoming more frequent in the present decade or so. This is contributing to the ever increasing human suffering of the region. In this study the whole energy parameter E from atmospheric energetic theory is derived. The characteristics of atmospheric energy conversion during the heavy rainfall in Pakistan for the period 27-29 July, 2010 are also discussed. The results show that due to the impact of the atmospheric circulation and terrain conditions, the kinetic energy is converted into potential energy, in the form of standing wave, during heavy rainfall development period. The conversion between kinetic and potential energy is significant in heavy rainfall spell. High energy value corresponds to the heavy rainfall region.


2021 ◽  
pp. 41-51
Author(s):  
D. S Lobanov ◽  
E. M Lunegova ◽  
A. I Mugatarov

Aging of composites is a pervasive problem that leads to mechanical properties degradation, reduced design life of a structure and premature accidental failure. The work is devoted to an experimental study of the preliminary temperature aging effect on the residual mechanical properties of structural CFRP. The joint use of test systems and systems for registration and analysis of acoustic emission signals was applied. The Short Beam Shear Test of CFRP specimens were carried out using the short beam method. The tests were carried out on universal electromechanical systems Instron 5882 and Instron 5965 in accordance with the recommendations of ASTM D2344. In the process of loading the samples were continuously recorded by using the acoustic emission signals system AMSY-6. A piezoelectric sensor with a frequency range of 300-800 kHz was used. The test and diagnostic systems were synchronized during the tests. In the course of the work the values of the interlayer shear strength were determined for the samples of CFRP. Typical types of the sample destruction are illustrated. When analyzing the change in the mechanical properties of the carbon fiber reinforced plastic from a temperature increase the critical values of temperatures were established in which a sharp decline in the strength and elastic characteristics of materials occurs due to an active destruction of the binder. The graphs of the energy parameter dependence and frequency characteristics of acoustic emission signals on time have been constructed and analyzed. The estimate of the processes of damage accumulation in composites is carried out. The change of the damage accumulation mechanisms was illustrated. The obtained results illustrate the effect of elevated temperatures and the duration of their impact on the mechanical behavior of structural CFRP specimens during the static tests for the interlayer shear.


2021 ◽  
Vol 2 (4) ◽  
pp. 73-78
Author(s):  
Anna Fedoriv ◽  
Ivan Fedoriv

The pathologic development of the atherosclerotic process is often associated with the metabolism of saturated and unsaturated fatty acid. Substitution of the saturated fatty acids in nutrition for polyunsaturated fatty acids is traditionally associated with the lowering of risk of coronary breaches rise. Understanding the molecular mechanisms of the atherosclerosis development and progress is very important for early diagnostic and effective medical treatment of the above-mentioned disease. After a thorough analysis of the data available on the pathological atherosclerotic process, we have come to the conclusion that this disease begins from vascular smooth muscle cell (VSMC) impaired function. In the basis of the atherosclerosis development lies isoprenes biogenesis breach, caused by cholesterol and the products of its metabolism. Atherosclerosis is a chronic inflammatory disease of the media wall of large- and medium-sized arteries. And endothelium injury is a consequence of the pathologic process progressing in myocytes. Metabolic problems have become so relevant that it is time to form a metabolic policy. Real target programs for the prevention of the development of metabolic diseases and their diagnostics in the early stages of development should be developed. But in order to achieve this goal, it is necessary to know the real molecular mechanism of development of the early stages of metabolic diseases. It is necessary to recognize that the research work on the metabolic problem was carried out mainly in the plane of the functionally-energy parameter and captures only the consequences of the pathological process. And the very reason and early stages of metabolic diseases remained hidden from us, as they are depending on the pathology in the plane Regulatory, Information, Coordination and Functional active bioenergy system.


2021 ◽  
Vol 8 (12) ◽  
pp. 25-35
Author(s):  
Sarkisov et al. ◽  

The relevance of the subject matter is conditioned by the technical complexity of the oil and gas facilities due to the increase in the volume and rate of raw materials production, which may be affected by shock-wave loads in emergency situations. The causes of the impact can be explosions, heavy cargo falls, terrorist attacks, natural and anthropogenic disasters, etc. These situations are very likely to cause significant damage to the building structures of industrial facilities, which necessitates their reinforcement. For further safe operation of the facility, reinforced structures must have survivability under repeated impacts no less than before the reinforcement. Given the fact that the survivability of buildings is a complex characteristic influenced by many factors, and it itself is a component of the security of a hazardous production facility, research in this area is topical. The purpose of the study is to test the developed method for assessing the survivability of a building structure under short-term shock-wave load based on the energy parameter and to analyze the results obtained in the context of assessing the security of critical oil and gas facilities. Research methods: Measurement of accelerations, deflections, and loads by strain measurement methods, graphoanalytical method of study using the Microsoft Excel software. A method for assessing the level of survivability of a building structure under shock-wave loading for critical oil and gas facilities using the survivability coefficient is developed. Using specific tests of conventional and cage-reinforced bending concrete elements for short-term dynamic load, the values of the specified coefficient are obtained. The values are compared and conclusions are drawn.


2021 ◽  
Vol 24 (1) ◽  
pp. 25-32
Author(s):  
Mykola Karpenko ◽  
Olegas Prentkovskis ◽  
Šarūnas Šukevičius

Reliability and maintenance analysis of transport machines hydraulic drives, basically focused to power units: pumps, cylinders etc., without taking in to account junction elements. Therefore, this paper proposes a research analysis on high-pressure hoses and junctions during technical maintenance. Comparative analysis of fluid behavior and energy efficiency inside non-repaired and repaired high-pressure hoses is presented in this research. Theoretical and experimental research results for hydraulic processes inside high-pressure hose is based on the numerical simulations using Navier–Stokes equations and experimental measurement of fluid flow pressure inside high-pressure hoses. Research of fluid flow dynamics in the hydraulic system was made with main assumptions: system flow rate in the range from 5 to 100 l/min, diameter of the hoses and repairing fitting are 3/8". The pressure drops, power losses, flow coefficients at non-repaired and after maintenance hose was obtained as a result. Simulation results were verified by running physical experiments to measure the pressure losses.


2021 ◽  
Vol 11 (22) ◽  
pp. 10837
Author(s):  
Jintao Su ◽  
Zhaoxiang Deng

Due to the difficulty of obtaining statistical energy parameters of complex structures and the complexity of modeling connection and model verification, the hybrid FE-SEA model has many problems in modeling complex structures. Therefore, in order to solve the above problems, this paper provides a reference for the application of the hybrid FE-SEA model in complex structures. In this paper, the hybrid FE-SEA commercial vehicle model is established by an experimental statistical energy parameter modeling method and a modification method. The model division and subsystem connection modeling of a complex substructure of a heavy vehicle cab are studied. In the hybrid model, the hybrid line connection and the hybrid point connection are established. On this basis, the parameters of the cab model were studied, and the statistical energy parameters such as modal density, internal loss factor, and coupling loss factor were obtained by the experimental method. The statistical energy parameters of the cab acoustic model are modified. Finally, the accuracy of the model is verified by vehicle test. In addition, the acoustic performance of the cab was optimized, and airtightness and acoustic packaging were verified. The full parameter modeling and correction method is adopted in this paper, which is an effective supplement to the traditional statistical energy parameter modeling method.


2021 ◽  
Vol 39 (5) ◽  
pp. 1557-1566
Author(s):  
Cherlacola Srinivas Reddy ◽  
Besthapu Prabhakar

This framework analyzes the impact of activation energy (AE) and binary chemical reaction (BCR) in Darcy-Forchheimer flow of cross fluid with nanoparticles due to radially stretched surface. Moreover slip, joule heating and viscous dissipation aspects have been considered. Ordinary differential equations acquired from the modelled governing partial differential equations with the assistance of suitable transformations. Further the system of nonlinear equations is computed numerically by Runge-Kutta-Fehlberg method cum shooting technique. Graphical representation has been given to analyze the velocity, temperature and concentration fields with the effect of various pertinent parameters. It is evident that inertia coefficient declines the velocity. Velocity decays for larger Weissenberg number while opposite trend observed in temperature field. Temperature field rises for augmented values of Eckert number. Concentration increases with increase of energy parameter.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naila Shaheen ◽  
Hashim M. Alshehri ◽  
Muhammad Ramzan ◽  
Zahir Shah ◽  
Poom Kumam

AbstractIn this study, the effects of variable characteristics amalgamated with chemical reaction and Arrhenius activation energy are analyzed on a two-dimensional (2D) electrically conducting radiative Casson nanoliquid flow past a deformable cylinder embedded in a porous medium. The surface of the cylinder is deformable in the radial direction i.e., the z-axis. The impression of Soret and Dufour's effects boosts the transmission of heat and mass. The flow is analyzed numerically with the combined impacts of momentum slip, convective heat, and mass conditions. A numerical solution for the system of the differential equations is attained by employing the bvp4c function in MATLAB. The dimensionless protuberant parameters are graphically illustrated and discussed for the involved profiles. It is perceived that on escalating the velocity slip parameter and porosity parameter velocity field depreciates. Also, on escalating the radiation parameter and heat transfer Biot number a prominent difference is noticed in an upsurge of the thermal field. For growing values of Brownian motion and thermophoretic parameters, temperature field augments. On escalating the curvature parameter and porosity parameter, drag force coefficient upsurges. The outcome of the Soret number, mass transfer Biot number, and activation energy parameter is quite eminent on the concentration distribution for the sheet in comparison to the deformable cylinder. A comparative analysis of the present investigation with an already published work is also added to substantiate the envisioned problem.


Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1470
Author(s):  
Evgenii Borisov ◽  
Kirill Starikov ◽  
Anatoly Popovich ◽  
Tatiana Tihonovskaya

In this work a study of the selective laser melting process of two NiTi alloys of equiatomic, and rich Ni composition were conducted. A study of the influence of the technological parameters on the alloy density was carried out. Values of technological parameters were obtained to ensure production of samples with the lowest number of defects. When using process parameters with the same energy density but different values of the constituent technological parameters, the amount of nickel carried away by evaporation changed insignificantly. An increase in the energy density led to an increase in the amount of nickel carried away, causing final samples with lower Ni content. When using multiple laser processing in the low-energy parameter set, it was possible to achieve a decrease in the nickel content in the alloy, similar to that with single high-energy processing. DSC studies showed a significant increase in transformation temperatures upon repeated laser processing due to the higher evaporation of nickel. The use of double laser treatment gave a decrease in the final density of the sample compared to a single treatment, but its value is still higher than when using a single treatment with a higher energy density.


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