Stomatal rings: structure, functions and origin

2020 ◽  
Author(s):  
Anatoly Pautov ◽  
Svetlana Bauer ◽  
Olga Ivanova ◽  
Elena Krylova ◽  
Olga Yakovleva ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Cell Walls ◽  
Guard Cells ◽  
Flowering Plants ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Stomatal Complex ◽  
Subsidiary Cells ◽  
Characteristic Features

Abstract Stomatal rings are structural elements of stomata of some flowering plants, being found in various groups of eudicots. The presence of a stomatal ring on a stoma does not depend on stomatal complex types, dimensions of stomata or their density. The guard cells of these stomata lie on the subsidiary cells. The location of the outer ledges on the outer tangential walls of the guard cells and the position of the stomatal rings on the guard cell walls around the outer ledges or on the outer ledges themselves are also among the characteristic features of these stomata. To elucidate the role of the stomatal rings we applied modelling using the finite-element method. The modelling has shown that the outer ledges prevent movements of the outer tangential walls of the guard cells and stimulate movements of the inner tangential walls and the immersion of the opening stomatal pore in the epidermis. Stomatal rings can enhance this effect. They also prevent the movements of the outer ledges and the widening of the stomatal aperture between them during stoma opening. This type of stomata occurs in evergreen plants growing in diverse conditions.

THE ROLE OF FINITE ELEMENT METHOD IN CIVIL ENGINEERING

2018 ◽  
Vol 5 (02) ◽  
Author(s):  
Er. Hardik Dhull
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Approximate Solution ◽  
Analytical Method ◽  
Civil Engineering ◽  
The Finite Element Method ◽  
Engineering Problems ◽  
Building Components ◽  
Element Method

The finite element method is a numerical method that is used to find solution of mathematical and engineering problems. It basically deals with partial differential equations. It is very complex for civil engineers to study various structures by using analytical method,so they prefer finite element methods over the analytical methods. As it is an approximate solution, therefore several limitationsare associated in the applicationsin civil engineering due to misinterpretationof analyst. Hence, the main aim of the paper is to study the finite element method in details along with the benefits and limitations of using this method in analysis of building components like beams, frames, trusses, slabs etc.

The Qualification of Safety Critical Structures by Finite Element Analytical Methods

1996 ◽  
Vol 210 (2) ◽  
pp. 203-207 ◽  
Author(s):  
A J Morris
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Error Control ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Method Error ◽  
Safety Critical ◽  
Critical Situation ◽  
Error Treatment

The paper introduces the concept of certifying or qualifying structures in a safety critical situation using the finite element method. Error control and error treatment methods for this purpose are discussed together with the associated role of testing. The underlying methodology follows the principles laid down in the SAFESA (SAFE Structural Analysis) method which is described in outline.

The Use of Topology Optimization in Shaping the Strength of Castings

2014 ◽  
Vol 223 ◽  
pp. 62-69 ◽  
Author(s):  
Stanisław Pysz ◽  
Marcin Małysza ◽  
Jarosław Pieklo
Keyword(s):  
Finite Element Method ◽  
Topology Optimization ◽  
Preliminary Design ◽  
Design Phase ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Mine Shaft ◽  
Casting Technology ◽  
Computer Calculations ◽  
Abaqus Software

The article discusses some of the issues associated with the use of topology optimization in shaping of the strength of castings. This kind of optimization is performed in the preliminary design phase, when the shape of the constructed part is not yet defined. The limitations that apply to the designing process concern the dimensions, boundary conditions, loads, forces, and cooperation with other structural elements. Topology optimization determines the arrangement of the material in space, so that under the conditions of loads, exploitation, and the design assumptions, the construction will have smallest possible weight. The article presents a few methods of optimization and provides simple examples. The computer calculations were carried out based on, the Finite Element Method (the Abaqus software), and the authors’ subroutines optimization algorithm that uses the results obtained in FEM. The example of the method to optimize the shape of mine shaft tubing is presented. The verification of the casting technology was conducted in MAGMASoft, taking into account the influence of the topology optimization on the production possibilities.

scholarly journals NUMERICAL ANALYSIS OF STRUCTURAL ELEMENTS BETWEEN 3D CAD SOLIDWORKS AND CODE_ASTER

2020 ◽  
Vol 7 (10) ◽  
pp. 458-470
Author(s):  
Benício de Morais Lacerda ◽  
Alex Gomes Pereira
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Complex Problem ◽  
Numerical Results ◽  
Good Precision ◽  
Institutional Research ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Numerical Application ◽  
Element Method

This study aimed to investigate numerically the validation of the use of the free license program Code_ Aster, with numerical results of the SolidWorks program. For this, four metal elements were modeled, all of them subjected to the tensile stress, they are: a cylindrical bar, two plates with a hole and a metal console. The objective is to validate the use of a free program for analysis of structural elements in engineering office projects and institutional research to verify if the results obtained from the free program show significant differences in the numerical application of a commercial program. All programs have in their design of analysis the use of the finite element method (FEM). The finite element method (FEM) consists to divide a continuous object into a finite number of parts. This allows a complex problem to be transformed into a set of simple problems (finite element) in addition to solving a set of finite elements by approximations with good precision of the results and to model the problem in a real physical way. It was observed that the numerical results between the SolidWorks program and the free program Code_ Aster were close with differences of less than 5%, which indicates the reliability of the use of Code_ Aster for numerical analyzes of structural elements of engineering projects and also in institutional research.

Role of trabecular microfractures in failure of human vertebrae estimated by the finite element method

2009 ◽  
Author(s):  
Irina N. Sidorenko ◽  
Jan Bauer ◽  
Roberto Monetti ◽  
Dirk Müller ◽  
Ernst J. Rummeny ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
The Finite Element Method ◽  
Element Method

MODAL ANALYSIS OF LINEAR ACTUATOR

2018 ◽  
pp. 38-43
Author(s):  
A. V. Gorbunov ◽  
O. I. Zheltyshev ◽  
N. G. Yakovenko
Keyword(s):  
Finite Element Method ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Linear Actuator ◽  
Earth Orbit ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Natural Oscillations ◽  
Space Applications ◽  
Comparative Results

The question of checking the linear drive for resistance to resonance in the structure of the precision positioning mechanism for space applications - hexapod, when it is taken to a near-earth orbit is considered. Calculation of the values of the natural frequencies of the structure is carried out by the finite element method using CAD. The application of the modal analysis of structural elements is presented on the example of the linear actuator case for evaluating the resistance to resonance as one of the criteria for selecting a material. The comparative results of the modal analysis for the variants of the linear actuator housing are presented. Modal analysis of the linear drive is carried out, calculated frequencies and forms of natural oscillations are presented. The initial data for the harmonic analysis of the linear drive are obtained. The compliance of the developed linear drive with the specified requirements has been confirmed.

NUMERICAL ANALYSIS OF ENGLISH BOWS USED IN BATTLE OF CRÉCY

2017 ◽  
pp. 69-85
Author(s):  
Mariusz MAGIER ◽  
Adrian Nowak ◽  
Tomasz , MERDA ◽  
Paweł Żochowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steel Plate ◽  
Flight Path ◽  
The Finite Element Method ◽  
Penetration Process ◽  
Technical Parameters ◽  
Simulation Process ◽  
Maximum Range

The paper presents simulation of flight path of an arrow shot with a longbow and its penetration process through a steel plate imitating an armor of a medieval heavy cavalry knights used during the Battle of Crécy on 26 August, 1346. The battle was a turning moment which had settled the specific role of the English bow in tactics and methods of its deployment on battle fields for almost 200 years until the firearms such as arquebuses or muskets started to be commonly used. The basic technical parameters necessary for the simulation process are based on historical information. On the basis of numerical calculations, the parameters of the flight path of the arrow with the "anti-armor" head were determined up to the maximum range. Thanks to use of the finite element method (AUTODYN) the penetration capacity of the arrow shot from longbow against horseman’s armor of XIV century was estimated.

Differential expression of K+ channels between guard cells and subsidiary cells within the maize stomatal complex

Planta ◽  
2005 ◽  
Vol 222 (6) ◽  
pp. 968-976 ◽  
Author(s):  
Kai Büchsenschütz ◽  
Irene Marten ◽  
Dirk Becker ◽  
Katrin Philippar ◽  
Peter Ache ◽  
...  
Keyword(s):  
Differential Expression ◽  
Guard Cells ◽  
Stomatal Complex ◽  
K Channels ◽  
Subsidiary Cells

Estimation of Sound Absorption Performance of Complex Perforated Panel Absorbers by Numerical Finite Element Method and Examinining the Role of Different Layouts Behind It

2019 ◽  
Vol 18 (03) ◽  
pp. 1950013
Author(s):  
Z. Hashemi ◽  
M. R. Monazzam ◽  
A. Fahim
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sound Absorption ◽  
Current Method ◽  
The Finite Element Method ◽  
Impedance Tube ◽  
Absorption Performance ◽  
Numerical Finite Element ◽  
Element Method

Perforated panels are one of the structures that are widely used nowadays. The sound absorption behavior of materials is studied by solving the equations governing the wave propagation in these materials. In this paper, the finite element method (FEM) was used to predict the absorption performances of few different perforated composite panels. Also, the studied structures were examined by two-microphone impedance tube to validate the results of the numerical method. The relative consistency of the results of the current method with the results of the impedance tube suggests the accuracy of this method in simulating the absorption rate of perforated composites. In addition, the results of evaluating various layouts (arrangements) showed that the use of absorber materials with higher flow resistivity at the back of the perforated panel and at the beginning of the sound wave entry increases the absorption performance by 1.6 times than that of the inverse layout ratio.

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