Experience of experimental studies and mathematical modeling of the impacts of deforestation and subsequent reforestation on the runoff and removal of chemicals from forest watersheds

2019 ◽  
Vol 55 (1) ◽  
pp. 25
Author(s):  
S. A. Kondratyev ◽  
Yu. V. Karpechko ◽  
M. V. Shmakova ◽  
A. M. Rasulova ◽  
V. Z. Rodionov ◽  
...  
2021 ◽  
Vol 1037 ◽  
pp. 369-376
Author(s):  
Maxim Ilyushkin ◽  
Kirill Savelev ◽  
Oleg Krupennikov ◽  
Evgeniy S. Kiselev

The paper presents the results of numerical experimental studies of cutting titanium blanks using mathematical modeling programs, which make it possible to completely repeat technological processes in a computer (digital twin). The LS-DYNA product was used as a program to simulate the process of stock removal from titanium blank. It has been established that the use of this method adequately describes the cutting processes, including with the introduction of the energy of an ultrasonic field into the processing zone, can significantly reduce the duration of experimental research and evaluate the influence of the elements of the cutting mode and design parameters of the tool on the thermal power aspects of the formation of new surfaces of machine parts.


2001 ◽  
Vol 1 (4) ◽  
pp. 73-79 ◽  
Author(s):  
C.R. O'Melia ◽  
J.Y. Shin

The performance of packed beds using dual media for removing particles is examined using both predictive mathematical modeling and experimental column studies. Models for the effectiveness of clean filter beds were used to simulate the effects of chemical pretreatment and filtration rate on particle removal at the onset of filtration runs. Experimental studies were conducted over complete filtration runs and were evaluated using measurements of head loss development and removals of turbidity, UV254 absorbance, and particles. The results indicate that dual media beds have significant advantages over monomedia beds during both filter ripening and filter breakthrough; they are particularly helpful at high filtration rates and during periods of inadequate chemical pretreatment. Finally, particle counts provide an earlier indicator of deteriorating filter performance than turbidity measurements at the end of a run.


2015 ◽  
Vol 2015 ◽  
pp. 1-28 ◽  
Author(s):  
Dariusz Grzelczyk ◽  
Jan Awrejcewicz

Mathematical modeling, theoretical/numerical analysis, and experimental verification of wear processes occurring on the contact surface of friction linings of a mechanical friction clutch are studied. In contrast to many earlier papers we take into consideration wear properties and flexibility of friction materials being in friction contact. During mathematical modeling and numerical simulations we consider a general nonlinear differential model of wear (differential wear model) and a model of wear in the integral form (integral wear model). Equations governing contact pressure and wear distributions of individual friction linings, decrease of distance between clutch shields, and friction torque transmitted by the clutch are derived and compared with experimental data. Both analytical and numerical analyses are carried out with the qualitative and quantitative theories of differential and integral equations, including the Laplace transform approach to ODEs. We show that theoretical results and numerical simulations agree with the experimental data. Finally, a numerical analysis of the proposed mathematical models was carried out in a wider range of parameters of the considered system.


2011 ◽  
Vol 22 (7) ◽  
pp. 909-910 ◽  
Author(s):  
Daniel A. Fletcher

In theory, the combination of mathematical modeling with experimental studies can be a powerful and compelling approach to understanding cell biology. In practice, choosing appropriate problems, identifying willing and able collaborators, and publishing the resulting research can be remarkably challenging. To provide perspective on the question of whether and when to combine modeling and experiments, a panel of experts at the 2010 ASCB Annual Meeting shared their personal experiences and advice on how to use modeling effectively.


2016 ◽  
Vol 20 (2) ◽  
pp. 81-89
Author(s):  
Monika Gwadera

AbstractThe aim of this paper is to present the adsorption chillers technology. The operating principle of these systems, the adsorbent-adsorbate pairs that are frequently applied and the enhancement techniques that allow improvement of their efficiency are presented. Analysis of the mass transfer and principles of mathematical modeling of such systems are also discussed. In the further part of the text, the results of experimental studies and comparison of these results with calculations based on the mathematical model of adsorption were presented.


2021 ◽  
Vol 2131 (3) ◽  
pp. 032056
Author(s):  
M Ahmedov ◽  
M Shoraxmedova ◽  
T Tuychiev ◽  
D Tashpulatov ◽  
I Cherunova

Abstract In article are brought algorithm and results brought numerically-experimental studies on qualitative and quantitative estimation of the law of the moving the raw cotton from directing walls outgoing between spiked-drum and netlike surface feeder aside worker of the camera ginning machines. It is known that the uniform supply of raw cotton to the ginning process has a direct impact on the efficiency of the ginning process. In the process of ginning, the cotton is cleaned on the surface of the pile drum and net of the supplier, and the crushed gin comes to the working chamber through the gin. As a result of the rotation of the saw cylinder in the working chamber, the cotton fiber is suspended and the rotation is started. As a result of the circular motion of the raw cotton, a raw material roller is formed. In this process, the actual problem is to ensure that the raw cotton consists of small pieces and is uniform in time and width of the equipment. The Comparison got given on calculation shows that increase the corner will bring about increase the growing forming displacement. Increase of this corner will bring the leaflet of the raw cotton about increase of length free moving.


2021 ◽  
Vol 288 ◽  
pp. 01058
Author(s):  
Andrew Tychkin ◽  
Andrew Yablokov ◽  
Vladimir Lebedev ◽  
Nikita Rodin ◽  
Maksim Batmanov

Ferroresonance phenomena lead to damage to electromagnetic measuring voltage transformers and nearby equipment. Damping devices and antiresonance transformers, which are used for preventing the occurrence of ferroresonance phenomena, are effective in a certain area of influencing factors. The article presents methods for studying the possibility of occurrence of ferroresonance phenomena in the operation of 6-220 kV voltage transformers based on physical and mathematical modeling. The results of the tests according to the developed method are the area of the existence of a dangerous ferroresonance for the voltage transformer under test or the confirmation of its antiresonance properties in a certain range of influencing factors under study. The article also describes an experimental setup based on RTDS for conducting experimental studies. The developed methods were tested in the studies of one of the types of antiresonance transformers.


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