Research on the Modeling of Metal Material Properties Based on Logistic Model

2014 ◽  
Vol 875-877 ◽  
pp. 1076-1082
Author(s):  
Shi Yu Zhang ◽  
Xi Ling Li
Keyword(s):  
Mathematical Model ◽  
Statistical Methods ◽  
Material Properties ◽  
Logistic Model ◽  
Theoretical Study ◽  
Metal Material ◽  
Metal Materials ◽  
The Mathematical Model ◽  
Hardenability Curve

The fact that it is difficult to establish the mathematical model of metal materials by theoretical study method means that can be done by statistical methods. Happens to, the logistic model is more suitable for this work. This paper tries to establish the model of steel hardenability curve by transforming logistic model without a large number of specimens.

Enhancement the Solar Still Performance Using Chimney Exhaust Gases

2021 ◽  
Author(s):  
Hamdy Hassan
Keyword(s):  
Mathematical Model ◽  
Theoretical Study ◽  
Saline Water ◽  
Kutta Method ◽  
Solar Still ◽  
Climate Conditions ◽  
Exhaust Gases ◽  
Runge Kutta Method ◽  
The Impact ◽  
The Mathematical Model

Abstract In this paper, a theoretical study is presented on enhancement of the solar still performance by using the exhaust gases passing inside a chimney under the still basin. The impact of the exhaust gases temperature on the solar still temperature, productivity, and efficiency are considered. The performance of solar still with chimney is compared with that of conventional solar still. The study is carried out under the hot and climate conditions of Upper Egypt. A complete transient mathematical model of the physical model including the solar still regions temperatures, productivity, and heat transfer between the solar still and the exhaust gases are constructed. The mathematical model is solved numerically by using fourth-order Runge-Kutta method and is programmed by using MATLAB. The mathematical model is validated using an experimental work. The results show that the solar still saline water temperature increases and productivity with using and rising the exhaust gases. Furthermore, the impact of using exhaust gases on the still performance in winter is greater than in summer. using chimney exhaust gases at 75 °C and 125 °C enhances the daily freshwater yield of the conventional still by more than three times and about six times in winter, respectively, and about two and half times and more than three times in summer, respectively.

scholarly journals Developing an Analytical Model and Computing Tool for Optimizing Lapping Operations of Flat Objects Made of Alloyed Steels

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1343 ◽  
Author(s):  
Tudor Deaconescu ◽  
Andrea Deaconescu
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Material Properties ◽  
Depth Of Cut ◽  
Operation Optimization ◽  
Abrasive Grains ◽  
Finishing Process ◽  
Real World Applications ◽  
The Mathematical Model

Lapping is a finishing process where loose abrasive grains contained in a slurry are pressed against a workpiece to reduce its surface roughness. To perform a lapping operation, the user needs to set the values of the respective lapping conditions (e.g., pressure, depth of cut, the rotational speed of the pressing lap plate, and alike) based on some material properties of the workpiece, abrasive grains, and slurry, as well as on the desired surface roughness. Therefore, a mathematical model is needed that establishes the relationships among the abovementioned parameters. The mathematical model can be used to develop a lapping operation optimization system, as well. To this date, such a model and system are not available mainly because the relationships among lapping conditions, material properties of abrasive grains and slurry, and surface roughness are difficult to establish. This study solves this problem. It presents a mathematical model establishing the required relationships. It also presents a system developed based on the mathematical model. In addition, the efficacy of the system is also shown using a case study. This study thus helps systematize lapping operations in regard to real-world applications.

scholarly journals Water-In-Oil Emulsions through Porous Media and the Effect of Surfactants: Theoretical Approaches

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 620 ◽  
Author(s):  
Josue F. Perez-Sanchez ◽  
Nancy P. Diaz-Zavala ◽  
Susana Gonzalez-Santana ◽  
Elena F. Izquierdo-Kulich ◽  
Edgardo J. Suarez-Dominguez
Keyword(s):  
Mathematical Model ◽  
Porous Media ◽  
Theoretical Study ◽  
High Viscosity ◽  
Dispersed Phase ◽  
Interaction Energies ◽  
Theoretical Approaches ◽  
Heavy Crude ◽  
Oil Emulsions ◽  
The Mathematical Model

The most complex components in heavy crude oils tend to form aggregates that constitute the dispersed phase in these fluids, showing the high viscosity values that characterize them. Water-in-oil (W/O) emulsions are affected by the presence and concentration of this phase in crude oil. In this paper, a theoretical study based on computational chemistry was carried out to determine the molecular interaction energies between paraffin–asphaltenes–water and four surfactant molecules to predict their effect in W/O emulsions and the theoretical influence on the pressure drop behavior for fluids that move through porous media. The mathematical model determined a typical behavior of the fluid when the parameters of the system are changed (pore size, particle size, dispersed phase fraction in the fluid, and stratified fluid) and the viscosity model determined that two of the surfactant molecules are suitable for applications in the destabilization of W/O emulsions. Therefore, an experimental study must be set to determine the feasibility of the methodology and mathematical model displayed in this work.

Optimal Method of Selection of Water Lubricated Rubber Bearing Materials

2016 ◽  
Vol 705 ◽  
pp. 3-7 ◽  
Author(s):  
Zhao Chen ◽  
Yu Guang Li ◽  
She Sheng Zhang
Keyword(s):  
Mathematical Model ◽  
Material Properties ◽  
Operational Research ◽  
Optimal Selection ◽  
Optimal Method ◽  
Maximum Value ◽  
Rubber Bearing ◽  
Bearing Materials ◽  
The Mathematical Model ◽  
Selection Of

Excellent material can improve the function of water lubricated stern bearing. According to the material properties and the theory of operational research, the mathematical model of the optimal selection material of water lubricated rubber bearing is established. The condition of selecting materials is discussed. The expression of the maximum value is obtained by using software. The influence of material properties on the objective function is discussed.

Toothed Belt-Load Distribution

1983 ◽  
Vol 105 (3) ◽  
pp. 339-347 ◽  
Author(s):  
M. R. Naji ◽  
K. M. Marshek
Keyword(s):  
Mathematical Model ◽  
Friction Force ◽  
Coefficient Of Friction ◽  
Material Properties ◽  
Load Distribution ◽  
Experimental Results ◽  
Spring Constant ◽  
Pitch Difference ◽  
Toothed Belt ◽  
The Mathematical Model

A mathematical model was developed to study the effect on belt load distribution of belt material properties, pitch variations, friction force, and pulley rotation. Results are presented which show the influence on load distribution of pitch difference, tight side tension, slack side tension, belt tooth spring constant, and coefficient of friction, for the belt on stationary, driver, and driven pulleys. Data from the mathematical model compared well with experimental results available in the literature.

scholarly journals Enhanced Thermoelectric Cooling through Introduction of Material Anisotropy in Transverse Thermoelectric Composites

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2049
Author(s):  
Bosen Qian ◽  
Fei Ren ◽  
Yao Zhao ◽  
Fan Wu ◽  
Tiantian Wang
Keyword(s):  
Mathematical Model ◽  
Single Crystal ◽  
Material Properties ◽  
Cooling Capacity ◽  
Thermoelectric Performance ◽  
Cooling Power ◽  
Material Anisotropy ◽  
Element Analysis ◽  
The Mathematical Model ◽  
Component Phase

Transverse thermoelectric materials can achieve appreciable cooling power with minimal space requirement. Among all types of material candidates for transverse thermoelectric applications, composite materials have the best cooling performance. In this study, anisotropic material properties were applied to the component phase of transverse thermoelectric composites. A mathematical model was established for predicting the performance of fibrous transverse thermoelectric composites with anisotropic components. The mathematical model was then validated by finite element analysis. The thermoelectric performance of three types of composites are presented, each with the same set of component materials. For each type of component, both anisotropic single-crystal and isotropic polycrystal material properties were applied. The results showed that the cooling capacity of the system was improved by introducing material anisotropy in the component phase of composite. The results also indicated that the orientation of the anisotropic component’s property axis, the anisotropic characteristic of a material, will significantly influence the thermoelectric performance of the composite. For a composite material consisting of Copper fiber and Bi2Te3 matrix, the maximum cooling capacity can vary as much as 50% at 300 K depending on the property axis alignment of Bi2Te3 in the composite. The composite with Copper and anisotropic SnSe single crystal had a 51% improvement in the maximum cooling capacity compared to the composite made of Copper and isotropic SnSe polycrystals.

Theoretical Study on the Wetting Length in Triangle Wetting Region of Rectangular Microgrooves

2011 ◽  
Author(s):  
Tao Wang ◽  
Xuegong Hu ◽  
Chaohong Guo ◽  
Xuelei Nie ◽  
Ningning Xie
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Theoretical Analysis ◽  
Tilt Angle ◽  
Heat Sink ◽  
Theoretical Study ◽  
Geometric Dimension ◽  
The Mathematical Model ◽  
The Relationship ◽  
Working Liquid

The mathematical model is established in this article to describe the relationship between the wetting length of working liquid in the triangular wetting region of rectangular capillary microgrooves and the geometric dimension, tilt angle, type of working liquid and heat flux when heating the back of microgrooves heat sink. The model supposes that the vapour-liquid interface of meniscus is quadratic parabola but not arc. The predictions from the theoretical analysis are successfully compared with the experimental results.

scholarly journals Mathematical Model for Charpy Impact Energy of V-Notch Specimens

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Wei Wang ◽  
Ping Wang ◽  
Xuesong Liu ◽  
Zhibo Dong ◽  
Hongyuan Fang
Keyword(s):  
Mathematical Model ◽  
Impact Energy ◽  
Material Properties ◽  
Theoretical Basis ◽  
Impact Resistance ◽  
Charpy Impact ◽  
The Impact ◽  
The Mathematical Model ◽  
The Relationship ◽  
Derivation Process

Firstly, by analyzing the response of Charpy V-notch specimen impacted by pendulum, the relationship between specimen geometry, material properties, and impact energy is established and simplified, and the mathematical model for evaluating impact energy of specimens with different sizes is established. Then, the effectiveness of the model through a series of impact tests is verified. Theoretical analysis and experimental results show that the relationship between ligament length and impact energy is quadratic, while the relationship between ligament thickness and impact energy is linear. In the derivation process, the intrinsic impact toughness is used to evaluate the toughness of materials. The mathematical model makes it possible to evaluate the impact energy of specimens with different sizes and provides a theoretical basis for evaluating the impact resistance of structures.

Control of the stirred flow reactor in unstable state control through step changes in the volume of the reaction mixture

1979 ◽  
Vol 44 (1) ◽  
pp. 34-49
Author(s):  
Josef Horák ◽  
František Jiráček ◽  
Zina Sojková
Keyword(s):  
Mathematical Model ◽  
Theoretical Study ◽  
Flow Reactor ◽  
Unstable State ◽  
Theoretical Studies ◽  
State Control ◽  
Ferric Ions ◽  
First Order ◽  
The Mathematical Model ◽  
Oxidation By Hydrogen Peroxide

Possibilities of the control of an adiabatic stirred flow reactor with an exothermic first order reaction in unstable state are studied. The control is studied both on the linearized mathematical model and on the model reaction of oxidation by hydrogen peroxide catalyzed by ferric ions. The control is based on step changes in the volume of the reaction mixture at constant conditions at the reactor inlet. The aim is stabilization of the outlet degree of conversion of the reactant. From the theoretical study on the mathematical model resulted that control of the reactor by step changes of the volume can be a very simple and effective method of control in the unstable steady state. The results of theoretical studies have been verified experimentally.

Equilibrium in the Population of the Plants

2019 ◽  
pp. 1-18
Keyword(s):  
Mathematical Model ◽  
Plant Development ◽  
Equilibrium Position ◽  
Logistic Model ◽  
Plant Population ◽  
The Real ◽  
Model Based ◽  
Wide Range ◽  
Living Organisms ◽  
The Mathematical Model

On the basis Mendel's experiments, a mathematical model is constructed that describes the results of these experiments in a wide range of parameters. This model is compared with the Hardy-Weinberg logistic model based only on probabilistic ideas about the presence of dominant and recessive alleles in the chromosomes of living organisms. There is shown that in the mathematical model of Mendel's experiments, based on real patterns of plant development, there are equilibrium positions between the dominant and recessive forms. It consists in the fact that with an increase in the number of generations all dominant and recessive phenotypes of organisms, with any number of sings, quickly equalize and then synchronously (in the absence of death of organisms) increase together, seeking asymptotically to a stable isolated equilibrium position of the type of a multidimensional node. This newly discovered behavior of the dominant and recessive forms in the vicinity of the equilibrium position (true) differs significantly from the logistic equilibrium position in the Hardy-Weinberg principle, built without taking into account the real patterns in the plant population.

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