Mathematical Modeling for the Accumulation of Cadmium, Zinc and Arsenic from the Soil in the Case of Bulrush Plant Type

2020 ◽  
Vol 70 (12) ◽  
pp. 4576-4583
Keyword(s):  
Mathematical Model ◽  
Linear Equations ◽  
Mathematic Model ◽  
Plant Type ◽  
High Accumulation ◽  
Plant Samples ◽  
Accumulation Capacity ◽  
The Mathematical Model ◽  
Non Linear Equations ◽  
Soil Interface

This paper proposes a tridimensional mathematical model of the accumulation of cadmium, arsenic and zinc from the soil in the case of bulrush plant type (the soil and plant samples was taken from two points along the Bistriţa River, belonging to the Siret hydrographic basin). The variable measures taken into consideration when carrying out the experiments and realizing the mathematical model are the distance from the water-soil interface from which the plant samples were taken and the content of cadmium, arsenic and zinc in the soil. The mathematical model was elaborated and tested by means of the TableCurve 3D program used for generating linear and non-linear equations. A reduced accumulation capacity of arsenic from the soil was registered. A high accumulation of cadmium from the soil was registered, in the case of bulrush plant type (765÷875 % higher than in the soil). The correlation coefficient of the mathematic model was between 0.94-0.99. Keywords: cadmium, arsenic, zinc, mathematic model, accumulation, Typha Latifola’s

Mathematical Modeling for the Absorption Capacity of Heavy Metals from the Soil in the Case of Phragmites Australis Plant Species

2019 ◽  
Vol 70 (7) ◽  
pp. 2545-2551
Author(s):  
Alexandra Dana Chitimus ◽  
Valentin Nedeff ◽  
Ion Sandu ◽  
Cristian Radu ◽  
Emilian Mosnegutu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Mathematical Model ◽  
Plant Species ◽  
Phragmites Australis ◽  
Mathematic Model ◽  
Absorption Capacity ◽  
Plant Samples ◽  
The Mathematical Model ◽  
Very High ◽  
High Absorption

This paper proposes a tridimensional mathematical model of the absorption capacity of heavy metals (cadmium and nickel) from the soil in the case of Phragmites Australis plant species (the soil and plant samples was taken from six locations/areas along the Bistri�a and Crac�u Rivers, belonging to the Siret hydrographic basin). The variable measures taken into consideration when carrying out the experiments and realizing the mathematical model are the distance from the water-soil interface from which the plant samples were taken and the concentration of the heavy metals in the soil. The mathematical model was elaborated and tested by means of the TableCurve 3D program used for generating linear and non-linear equations. A very high absorption capacity of cadmium from the soil was recorded A very high absorption capacity of cadmium from the soil was recorded, in the case of Phragmites Australis plant species (190�234 % higher than in the soil). The correlation coefficient of the mathematic model was between 0.90 and 0.98.

scholarly journals Introducing a Conditional Ghost Correction Into the Vector Method

1984 ◽  
Vol 6 (2) ◽  
pp. 117-123 ◽  
Author(s):  
H. Schaeben
Keyword(s):  
Mathematical Model ◽  
Quadratic Programming ◽  
Optimization Problem ◽  
Linear Equations ◽  
Singular System ◽  
Orientation Distribution ◽  
Mathematical Approach ◽  
System Of Linear Equations ◽  
Vector Method ◽  
The Mathematical Model

The concept of conditional ghost correction is introduced into the vector method of quantitative texture analysis. The mathematical model actually chosen here reduces the texture problem to one of quadratic programming. Thus, a well defined optimization problem has to be solved, the singular system of linear equations governing the correspondence between pole and orientation distribution being reduced to a set of equality constraints of the restated texture problem. This new mathematical approach in terms of the vector method reveals the modeling character of the solution of the texture problem provided by the vector method completely.

scholarly journals Evaluating the loads on bulldozer undercarriage under longitudinal trim

2020 ◽  
Vol 26 (3) ◽  
pp. 57-60
Author(s):  
Igor Kirichenko
Keyword(s):  
Mathematical Model ◽  
Mathematic Model ◽  
Operating Modes ◽  
The Mathematical Model

Based on the air-wheel type machines simulation, a bulldozer mathematic model for all its operating modes has been worked out. Evaluation of loads on the bulldozer undercarriage under longitudinal trim has been considered as an example of possible implementing the potential of the mathematical model proposed.

A mathematical model of psychotherapy: An investigation using dynamic non-linear equations to model the therapeutic relationship

2012 ◽  
Vol 22 (1) ◽  
pp. 40-55 ◽  
Author(s):  
Paul R. Peluso ◽  
Larry S. Liebovitch ◽  
John M. Gottman ◽  
Michael D. Norman ◽  
Jessica Su
Keyword(s):  
Mathematical Model ◽  
Therapeutic Relationship ◽  
Linear Equations ◽  
Non Linear ◽  
Non Linear Equations

scholarly journals On the Calculation of Variances and Credibilities by Experience Rating

1977 ◽  
Vol 9 (1-2) ◽  
pp. 203-207 ◽  
Author(s):  
K. Loimaranta
Keyword(s):  
Iterative Process ◽  
Linear Equations ◽  
The Other ◽  
Likelihood Principle ◽  
Experience Rating ◽  
Maximum Likelihood Principle ◽  
Image Position ◽  
The Mathematical Model ◽  
Non Linear Equations ◽  
General Method

By experience rating the main problem is to estimate the credibilities. We have for the credibility αk the famous formula)but it is often troublesome to find suitable estimates for the variances and . In the present paper a general method to estimate them from the actual statistics is given.A disadvantage of the method is that good estimates require relatively extensive statistical material. If one of the variances is known, the method can be easily modified to give the other variance from statistics of moderate size.The method is based on the Maximum Likelihood principle and leads to a system of non-linear equations. The equations can be solved by an iterative process, easily programmable for computers.The mathematical model underlying the experience rating problem differs in our case lightly from the usual one.

Mathematic Model of Displacement Control Unit for Screw Distributor of Asphalt Paver

2013 ◽  
Vol 774-776 ◽  
pp. 295-298
Author(s):  
Zhi Nan Mi ◽  
Long An Chen ◽  
Jia Tao Tang
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Control Unit ◽  
Mathematic Model ◽  
Displacement Control ◽  
Rotating Speed ◽  
Dynamical Characteristics ◽  
Inertial Element ◽  
The Mathematical Model

Displacement control unit is an important part of hydraulic system for screw distributor. By adjusting the angle of swashplate, it can change the flow rate of pump and rotating speed of screw distributor. The rotating speed of screw distributor has influence on quality of road. The mathematical model of displacement control unit is presented. Its dynamical characteristics are analyzed. The mathematical model includes a reset spring gradient. The reset spring gradient is much smaller than the hydraulic spring rate, the effect of the reset spring gradient can be neglected. So an inertial element can be substituted by an integration element.

Study on Establishment of Helix Flute Mathematic Model of Solid Carbide End Mills

2011 ◽  
Vol 121-126 ◽  
pp. 4753-4757
Author(s):  
Guo Chao Li ◽  
Jie Sun ◽  
Yong He
Keyword(s):  
Mathematical Model ◽  
Main Idea ◽  
Surface Group ◽  
Mathematic Model ◽  
End Mill ◽  
Cross Sectional ◽  
New Approach ◽  
Solid Carbide ◽  
End Mills ◽  
The Mathematical Model

This paper describes a new approach to establish the helix flute model of solid carbide end mills. Based on the theory of differential geometry and coordinate transformation, a mathematical model of the end mill helix flute will be established.The main idea of the study is to envelop the helix flute by a one-parameter surface group which consists of the cross-sectional profiles of the wheel.Then, the mathematical model will be quickly verified by MATLAB.Thus the end mill design time will be saved and the new mathematical model will be checked effectively.

scholarly journals Refinement of the parameters of a mathematical model of quadcopter dynamics

2020 ◽  
Vol 109 ◽  
pp. 141-151
Author(s):  
Adalat PASHAYEV ◽  
Elkhan SABZIEV
Keyword(s):  
Mathematical Model ◽  
Initial Period ◽  
Linear Equations ◽  
Three Dimensional ◽  
Mean Value ◽  
Design Stage ◽  
Control Parameters ◽  
Time Intervals ◽  
Aerodynamic Properties ◽  
The Mathematical Model

Errors in the calculation of the parameters of quadcopter control models at design stage significantly change the desired aerodynamic properties of the drone and make it difficult to control its flight along the intended path. Therefore, to calculate the adequate operation modes of the blades, it becomes necessary to refine some parameters of the mathematical model of the drone as accurately as possible. This paper shows the possibility of using control parameters (rotational speed of the blades) and information received from navigation devices of the drone to refine the values of the parameters of the mathematical model of the drone. For this purpose, a mathematical model of a quadcopter is built, and the problem of refining the parameters of its dynamic model is investigated based on the information received from navigation devices and the control parameters in the initial period of its flight. From the results obtained from several consecutive measurements, a system of equations expressing a mathematical model is solved. The mean value of the corresponding solutions of the system of three-dimensional linear equations obtained at different time intervals is the refined value of the parameters.

Research on Numerical Simulation of Gas Storage Field in Aquifer Based on Fully Implicit Method

2011 ◽  
Vol 383-390 ◽  
pp. 4467-4474
Author(s):  
Bao Hui Wang ◽  
Xiang Zhen Yan ◽  
Xiu Juan Yang
Keyword(s):  
Mathematical Model ◽  
High Stability ◽  
Linear Equations ◽  
Gas Injection ◽  
Injection Rate ◽  
Formation Pressure ◽  
Two Phase ◽  
Fully Implicit ◽  
Jacobi Iteration ◽  
The Mathematical Model

The mathematical model of Two-Phase flow of water and gas in aquifer is established based on the Darcy linear percolation law and law of conservation of mass of fluid mechanics. According to the fully implicit difference method, time and spatial discretization of the model lead to a set of nonlinear equations, which can be transferred into a group of linear equations. The linear equations can be solved using the Jacobi-iteration pretreatment because of its high stability and fast convergence speed of the solution positively. The distribution of the saturation and formation pressure with time in the process of gas injection is analyzed by using the mathematical model. The results show that the gas saturation increases with the gas injection rate, the permeability and reservoir thickness increasing whereas the formation pressure increases slowly under same cumulative gas injection rate. The formation pressure increases at first and then decreases to reach a steady value.

Mathematic Model for Analysing the Dynamic Behavior of a Vehicle in the Field of Chaotic Movements

2016 ◽  
Vol 822 ◽  
pp. 54-59 ◽  
Author(s):  
Loreta Simniceanu ◽  
Dumitru Neagoe ◽  
Mario Trotea ◽  
Mihaela Liana Bogdan ◽  
Augustin Constantinescu
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Phase Plane ◽  
Dynamic Behaviour ◽  
Functional Limitations ◽  
Power Spectra ◽  
Mathematic Model ◽  
Equivalent Model ◽  
The Mathematical Model ◽  
Vehicle Movement

This paper presents a plane equivalent model of the vehicle and its mathematical model attached. The mathematical model is under a form of four differential equations system of order 1, in order to analyze the dynamic behaviour of the vehicle movement. Its goal is to determine the ranges of speed for that movement is stable or is unstable, or having chaotic character. The authors consider being necessary to know the conditions in which movements occur chaotic movements to avoid them through constructive or functional limitations. Speed ​​values ​​are identified for the behaviour of the system is placed in the quasiperiodic movements field or exceeding these movements trough chaos and are highlighted by the specific instruments: the trajectories in the phase plane, Poincare section and power spectra.

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