scholarly journals Research of the reasons of increased drop in cotton seeds after generation with reduced density of raw roller

2021 ◽  
Vol 939 (1) ◽  
pp. 012072
Author(s):  
M Agzamov ◽  
I Radjabov ◽  
D Yuldashev
Keyword(s):  
Mathematical Model ◽  
Contact Pressure ◽  
Angular Speed ◽  
Numerical Results ◽  
Geometrical Parameters ◽  
Graphic Data ◽  
Cotton Seeds ◽  
Definition Of ◽  
In The Beginning ◽  
Reduced Density

Abstract Results of researches on definition of influence of density of the raw roller on pubescence of cotton seeds are given in article. The received mathematical model for calculation of contact pressure and movement of the raw roller in the form of a system from six equations with six unknown. The numerical results calculated on the computer. Sizes of shift and contact pressure for the set physic-mechanical and geometrical parameters of a system are determined. It is established that contact pressure significantly depends on elasticity (density) and angular speed of the raw roller. On the basis of the graphic data of contact pressure and contact movement of the raw roller received results of calculations the conclusion that with reduction of density of the raw roller conditions of capture of a short cotton slice worsen. The fact that the contact pressure and movement fluctuate during time is the reason of it, i.e. in the beginning the short cotton slice contacts to a saw, but during fractions of a second this contact is lost, also contact pressure similarly changes. Results of theoretical researches proved increase in a full pubescence of seeds after gin with reduction of density of the raw roller, i.e. one of the reasons of it is deterioration in conditions of capture of short cotton slices a saw - fluctuations of contact pressure and contact movement of the raw roller.

Parametric Analysis of a PULSCO Vent Silencer

2014 ◽  
Author(s):  
Usama Tohid ◽  
Chris Genger ◽  
John Kaiser ◽  
Ilaria Accorsi ◽  
Arturo Pacheco-Vega
Keyword(s):  
Mathematical Model ◽  
Parametric Study ◽  
Numerical Results ◽  
Operating Conditions ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Computational Domain ◽  
Hole Size ◽  
Plane Wave Solution ◽  
The Mathematical Model

We have conducted a parametric study via numerical simulations of a PULSCO vent silencer. The overall objective is to demonstrate the existence of an optimum system performance for a given set of operating conditions i.e., temperature, pressure, mass flow-rate and the working fluid, by modifying the corresponding geometry of the device. The vent silencer under consideration consists of a perforated diffuser, the silencer body and a tube module. The tube module consists of a set of tubes through which the working fluid passes. The flow tubes are perforated and surrounded with acoustic packing that is responsible for the attenuation. The mathematical model of the vent silencer is built upon Helmholtz equation for the plane wave solution, and the Delany-Bazley model for the acoustic packing. The geometrical parameters chosen for the parametric study include: the porosity of the diffuser and the flow tubes, the type of packing material used for the tube module, bulk density for the acoustic packing and the hole diameter of the perforated diffuser and flow tubes. The equations of the mathematical model are discretized over the computational domain and solved with a finite element method. Numerical results in terms of transmission loss, for the system, indicate that diffuser hole size of 1/4” with porosity of 0.1, flow tube hole size of 1/8” with porosity of 0.23, packing density of 16 kg/m3 for TRS-10 and 100 kg/m3 for Advantex provided the optimum results for the chosen set of conditions. The numerical results were found to be in agreement with experimental data.

Balance Equation - An Essential Element of the Definition of the Drying Process

2013 ◽  
Vol 849 ◽  
pp. 310-315 ◽  
Author(s):  
Imrich Orlovský ◽  
Michal Hatala ◽  
Ján Duplák
Keyword(s):  
Mathematical Model ◽  
Silicon Carbide ◽  
Balance Equation ◽  
Main Part ◽  
Ceramic Powder ◽  
Essential Element ◽  
Optimal Solutions ◽  
Drying Process ◽  
Definition Of ◽  
In The Beginning

The paper describes the basic principle of the proposal of a mathematical model drying. In the beginning of the article is a brief description of the material to be monitored during drying. Factors examined are the ceramic powder, which is obtained from spraying the emulsion in the drying kiln. Material is silicon carbide. It is further described principle of the drying process. The main part is to identify the parameters of the drying process, and it those that most influencing the actual drying and compilation of the balance equation. The aim of this article is find optimal solutions equation so that we can adequately define a mathematical model of the drying process and thus better control the process of drying - the quality (humidity) ceramic powder.

MODELING OF THE DYNAMIC PROCESS RELEASE OF STUCK DRILLING TOOLS BY HYDRO-PULSE METHOD

2019 ◽  
pp. 94-103
Author(s):  
K. H. Levchyk ◽  
M. V. Shcherbyna
Keyword(s):  
Mathematical Model ◽  
Dynamic Process ◽  
Drilling Fluid ◽  
Pulse Method ◽  
Geometrical Parameters ◽  
Technical Solution ◽  
Rock Layer ◽  
Drilling Tool ◽  
Drilling Tools ◽  
Drill Pipes

A technical solution is proposed for the elimination the grabbing of drilling tool, based on the use of energy due to the circulation of the drilling fluid. The expediency eliminating the grabbing drilling tool using the hydro-impulse method is substantiated. A method of drawing up a mathematical model for the dynamic process of a grabbing string of drill pipes in the case of perturbation of hydro-impulse oscillations in the area of the productive rock layer is developed. The law of longitudinal displacements arising in the trapped string is obtained, which allows choosing the optimal geometrical parameters of the passage channels and the frequency rotational of shutter for these channels. Recommendations for using this method for practical use have been systematized.

scholarly journals Theoretical Modeling, Design and Simulation of an Innovative Diverting Valve Based on Coanda Effect

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 103
Author(s):  
Giancarlo Comes ◽  
Carlo Cravero
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Water Flow ◽  
Coanda Effect ◽  
Geometrical Parameters ◽  
Convex Wall ◽  
Fluidic Device ◽  
Coandǎ Effect

The present work is focused on the study of an innovative fluidic device. It consists of a two-ways diverter valve able to elaborate an inlet water flow and divert it through one of the two outlets without moving parts but as a result of a fluctuation of pressure induced by two actuation ports, or channels. Such apparatus is named Attachment Bi-Stable Diverter (ABD) and is able to work with the effect of the fluid adhesion to a convex wall adjacent to it, this phenomenon is known as Coanda Effect; it generates the force responsible for the fluid attachment and the consequent deviation. The main purpose of this work is to develop a knowhow for the design and development of such particular device. A mathematical model for the ABD has been developed and used to find the relationships between the geometrical parameters and the operative conditions. A configuration has been designed, simulated with a computational fluid dynamics approach. A prototype has been printed with and additive manufacturing printer and tested in laboratory to check the effective working point of the device.

A MATHEMATICAL MODEL OF THE PHYSICAL GROWTH MECHANISM AND GEOMETRICAL CHARACTERIZATION OF GROWING FORMS

2011 ◽  
Vol 04 (01) ◽  
pp. 35-53 ◽  
Author(s):  
YURI K. SHESTOPALOFF
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Growth Mechanism ◽  
Growth Suppression ◽  
Physical Growth ◽  
Geometrical Parameters ◽  
Growth Equation ◽  
Software Application ◽  
Multicellular Organisms

The article introduces a mathematical model of the physical growth mechanism which is based on the relationships of the physical and geometrical parameters of the growing object, in particular its surface and volume. This growth mechanism works in cooperation with the biochemical and other growth factors. We use the growth equation, which mathematically describes this mechanism, and study its adequacy to real growth phenomena. The growth model very accurately fits experimental data on growth of Amoeba, Schizosaccharomyces pombe, E.coli. Study discovered a new growth suppression mechanism created by certain geometry of the growing object. This result was proved by experimental data. The existence of the growth suppression phenomenon confirms the real workings and universality of the growth mechanism and the adequacy of its mathematical description. The introduced equation is also applicable to the growth of multicellular organisms and tumors. Another important result is that the growth equation introduces mathematical characterization of geometrical forms that can biologically grow. The material is supported by software application, which is released to public domain.

scholarly journals Modelling Macrophage Infiltration into Avascular Tumours

2002 ◽  
Vol 4 (1) ◽  
pp. 21-38 ◽  
Author(s):  
C. E. Kelly ◽  
R. D. Leek ◽  
H. M. Byrne ◽  
S. M. Cox ◽  
A. L. Harris ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Spatial Structure ◽  
Random Motion ◽  
Numerical Results ◽  
Macrophage Infiltration ◽  
Numerical Techniques ◽  
Model Predictions ◽  
Independent Experimental Data

In this paper a mathematical model that describes macrophage infiltration into avascular tumours is presented. The qualitative accuracy of the model is assessed by comparing numerical results with independent experimental data that describe the infiltration of macrophages into two types of spheroids: chemoattractant-producing (hepa-1) and chemoattractant-deficient (or C4) spheroids. A combination of analytical and numerical techniques are used to show how the infiltration pattern depends on the motility mechanisms involved (i.e. random motion and chemotaxis) and to explain the observed differences in macrophage infiltration into the hepa-1 and C4 spheroids. Model predictions are generated to show how the spheroid's size and spatial structure and the ability of its constituent cells influence macrophage infiltration. For example, chemoattractant-producing spheroids are shown to recruit larger numbers of macrophages than chemoattractant-deficient spheroids of the same size and spatial structure. The biological implications of these results are also discussed briefly.

scholarly journals Engineering of Light Electric Commercial Vehicle

2020 ◽  
Vol 19 (1) ◽  
pp. 63-75
Author(s):  
R. Dorofeev ◽  
A. Tumasov ◽  
A. Sizov ◽  
A. Kocherov ◽  
A. Meshkov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Electric Vehicle ◽  
Electric Motor ◽  
Field Tests ◽  
Angular Speed ◽  
Maximum Energy ◽  
Driving Cycle ◽  
Thermal Calculation ◽  
Technical Solutions ◽  
The Mathematical Model

The paper describes the process and results of the development of the light commercial electric vehicle. In order to ensure maximum energy efficiency of the developed vehicle the key parameters of the original electric motor. The article also presents the results of power electronic thermal calculation. For the mathematical model of the vehicle, the driving cycle parameters of the electric platform were determined in accordance with UNECE Regulations No 83, 84. The driving cycle was characterized by four successive urban and suburban cycles. The mathematical model also takes into account the time phases of the cycle, which include idling, vehicle idling, acceleration, constant speed movement, deceleration, etc. The model of the electric part of the vehicle was developed using MatLab-Simulink (SimPowerSystems library) in addition to the mechanical part of the electric car. The electric part included the asynchronous electric motor, the motor control system and the inverter. This model at the output allows to obtain such characteristics of the electric motor as currents, flows and voltages of the stator and rotor in a fixed and rotating coordinate systems, electromagnetic moment, angular speed of rotation of the motor shaft. The developed model allowed to calculate and evaluate the performance parameters of the electric vehicle. Technical solutions of the electric vehicle design were verified by conducting strength calculations. In conclusion, the results of field tests of a commercial electric vehicle are presented.

scholarly journals A numerical fit of analytical to simulated density profiles in dark matter haloes

2005 ◽  
pp. 13-32 ◽  
Author(s):  
R. Caimmi ◽  
C. Marmo ◽  
T. Valentinuzzi
Keyword(s):  
High Resolution ◽  
Density Profile ◽  
Geometrical Parameters ◽  
Density Profiles ◽  
Mean Values ◽  
Geometrical Properties ◽  
Best Fitting ◽  
Definition Of ◽  
Additional Support ◽  
Open Question

Analytical and geometrical properties of generalized power-law (GPL) density profiles are investigated in detail. In particular, a one-to-one correspondence is found between mathematical parameters (a scaling radius, r0, a scaling density, ?0, and three exponents, ?, ?, ?), and geometrical parameters (the coordinates of the intersection of the asymptotes, xC, yC, and three vertical intercepts, b, b?, b?, related to the curve and the asymptotes, respectively): (r0,?0,?,?,?) ? (xC,yC,b,b?,b?). Then GPL density profiles are compared with simulated dark haloes (SDH) density profiles, and nonlinear least-absolute values and least-squares fits involving the above mentioned five parameters (RFSM5 method) are prescribed. More specifically, the sum of absolute values or squares of absolute logarithmic residuals, Ri=log?SDH(ri) ? log?GPL(ri), is evaluated on 10 points making a 5dimension hypergrid, through a few iterations. The size is progressively reduced around a fiducial minimum, and superpositions on nodes of earlier hypergrids are avoided. An application is made to a sample of 17 SDHs on the scale of cluster of galaxies, within a flat ?CDM cosmological model (Rasia et al. 2004). In dealing with the mean SDH density profile, a virial radius, Rvir, averaged over the whole sample, is assigned, which allows the calculation of the remaining parameters. Using a RFSM5 method provides a better fit with respect to other methods. The geometrical parameters, averaged over the whole sample of best fitting GPL density profiles, yield (?, ?, ?) ? (0.6,3.1,1.0), to be compared with (?, ?, ?) = (1,3,1), i.e. the NFW density profile (Navarro et al. 1995, 1996, 1997), (?, ?, ?) = (1.5,3, 1.5) (Moore et al. 1998, 1999), (?, ?, ?) = (1,2.5,1) (Rasia et al. 2004); and, in addition, ? ? 1.5 (Hiotelis 2003), deduced from the application of a RFSM5 method, but using a different definition of scaled radius, or concentration; and ? ? 1.21.3 deduced from more recent high-resolution simulations (Diemand et al. 2004, Reed et al. 2005). No evident correlation is found between SDH dynamical state (relaxed or merging) and asymptotic inner slope of the fitting logarithmic density profile or (for SDH comparable virial masses) scaled radius. Mean values and standard deviations of some parameters are calculated, and in particular the decimal logarithm of the scaled radius, ?vir, reads < log?vir >= 0.74 and ?slog?vir = 0.150.17, consistent with previous results related to NFW density profiles. It provides additional support to the idea, that NFW density profiles may be considered as a convenient way to parametrize SDH density profiles, without implying that it necessarily produces the best possible fit (Bullock et al. 2001). A certain degree of degeneracy is found in fitting GPL to SDH density profiles. If it is intrinsic to the RFSM5 method or it could be reduced by the next generation of high-resolution simulations, still remains an open question. .

scholarly journals Introduction

2009 ◽  
Vol 37 (3/4) ◽  
pp. 353-368
Author(s):  
Dario Martinelli
Keyword(s):  
Animal Species ◽  
Animal Communication ◽  
Recent Developments ◽  
Definition Of ◽  
In The Beginning

“Zoosemiotics” was introduced in 1963 by Thomas Albert Sebeok, initially as a compromise between ethological and semiotic research. In the beginning, Sebeok was convinced that “zoosemiotics” had to be used mostly as an umbrella term, uniting different scholarly approaches to animal communication). In the light of its most recent developments, a synthetic definition of zoosemiotics can be today that of the study of semiosis within and across animal species.

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