The Cement Paste Creep with Addition of Fly Ash in Time and Ratio of Parts 60/40

2013 ◽  
Vol 486 ◽  
pp. 341-346
Author(s):  
Pavel Padevět ◽  
Petr Bittnar
Keyword(s):  
Mathematical Model ◽  
Fly Ash ◽  
Cement Paste ◽  
Input Data ◽  
Basic Creep ◽  
Creep Coefficient ◽  
Measurement Results ◽  
The One ◽  
Water Saturated ◽  
The Mathematical Model

The article solves the comparing of the resize of cement paste creep with addition of fly ash in time. Creep was observed in the one monthly measurement for 4 and 10 months. The cement paste was prepared with fly ash in the ratio of the components 60/40 in favor of the cement components. Development of basic creep and creep was observed in water-saturated material. The measurement results are used as input data for the simulation of creep by the mathematical model and determine the values of the creep coefficient of cement paste. Results and comparison of q coefficients are presented.

Creep of Cementitous Materials with Addition of Fly Ash in Time

2013 ◽  
Vol 742 ◽  
pp. 182-186 ◽  
Author(s):  
Pavel Padevět ◽  
Petr Bittnar
Keyword(s):  
Fly Ash ◽  
Cement Paste ◽  
Experimental Measurements ◽  
Measurement Results ◽  
Water Saturated

The cement paste forms the basis of a concrete composite. This article is focused on the analysis of the creep of cement paste with fly ash based on experimental measurements. Measurement results of creep-dried and water saturated pastes are presented. The ratio of cement to fly ash of 1:1 was used for the production of the mixture. Experimental measurements were carried out on material age of 4 months.

scholarly journals The Impact of Elongation on Change in Electrical Resistance of Electrically Conductive Yarns Woven into Fabric

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3390
Author(s):  
Željko Knezić ◽  
Željko Penava ◽  
Diana Šimić Penava ◽  
Dubravko Rogale
Keyword(s):  
Mathematical Model ◽  
Electrical Resistance ◽  
Electrically Conductive ◽  
Textile Materials ◽  
Measurement Results ◽  
Conductive Yarns ◽  
Yarn Count ◽  
As Relationship ◽  
The Impact ◽  
The Mathematical Model

Electrically conductive yarns (ECYs) are gaining increasing applications in woven textile materials, especially in woven sensors suitable for incorporation into clothing. In this paper, the effect of the yarn count of ECYs woven into fabric on values of electrical resistance is analyzed. We also observe how the direction of action of elongation force, considering the position of the woven ECY, effects the change in the electrical resistance of the electrically conductive fabric. The measurements were performed on nine different samples of fabric in a plain weave, into which were woven ECYs with three different yarn counts and three different directions. Relationship curves between values of elongation forces and elongation to break, as well as relationship curves between values of electrical resistance of fabrics with ECYs and elongation, were experimentally obtained. An analytical mathematical model was also established, and analysis was conducted, which determined the models of function of connection between force and elongation, and between electrical resistance and elongation. The connection between the measurement results and the mathematical model was confirmed. The connection between the mathematical model and the experimental results enables the design of ECY properties in woven materials, especially textile force and elongation sensors.

scholarly journals AGV Brake System Simulation

2019 ◽  
Vol 10 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Daniel Varecha ◽  
Robert Kohar ◽  
Frantisek Brumercik
Keyword(s):  
Mathematical Model ◽  
Input Data ◽  
Initial Conditions ◽  
Brake System ◽  
Disc Brake ◽  
Hydraulic Control ◽  
Stopping Distance ◽  
Braking Force ◽  
Braking Process ◽  
The Mathematical Model

Abstract The article is focused on braking simulation of automated guided vehicle (AGV). The brake system is used with a disc brake and with hydraulic control. In the first step, the formula necessary for braking force at the start of braking is derived. The stopping distance is 1.5 meters. Subsequently, a mathematical model of braking is created into which the formula of the necessary braking force is applied. The mathematical model represents a motion equation that is solved in the software Matlab by an approximation method. Next a simulation is created using Matlab software and the data of simulation are displayed in the graph. The transport speed of the vehicle is 1 〖m.s〗^(-1) and the weight of the vehicle is 6000 kg including load. The aim of this article is to determine the braking time of the device depending from the input data entered, which represent the initial conditions of the braking process.

Effects of Powders on the Precision of a Powder Metallurgy Helical Gear

2007 ◽  
Author(s):  
Ming-Ta Yu ◽  
Chung-Biau Tsay
Keyword(s):  
Mathematical Model ◽  
Powder Metallurgy ◽  
Helical Gear ◽  
Precision Measurements ◽  
Manufacture Process ◽  
Measurement Results ◽  
Surface Deviations ◽  
Two Parameters ◽  
The Mathematical Model ◽  
The Relationship

This study refers to the conditions of practical powder metallurgy manufacture process, and proceeds to experiments and gear precision measurements as well as investigation on the effects of two parameters, powders and pitch circle radius, on gear precision. The relationship between gear parameters and gear surface deviations was derived from the mathematical model of the involute helical gear and the analysis of gear surface deviations. In accordance with the measurement results of experiments, an ideal correction on the parameters of a forming die is obtained from the computer simulations of gear surface deviations.

scholarly journals Kinetics of filtration consolidation of water-saturated clay soils

2020 ◽  
pp. 86-95 ◽  
Author(s):  
O. V. Ageikina ◽  
V. V. Vorontsov ◽  
R. R. Sufyanov
Keyword(s):  
Mathematical Model ◽  
Porous Medium ◽  
Saturated Porous Medium ◽  
Experimental Studies ◽  
Saturated Soils ◽  
Consolidation Process ◽  
Filtration Consolidation ◽  
Wide Range ◽  
Water Saturated ◽  
The Mathematical Model

The relevance of the research processes filtration consolidation due to the place of water-saturated soils in various design solutions related to the exploration, production and transportation of hydrocarbons. It should be noted that the diversity of soils led to the emergence of a wide range of mathematical models, obtained on the basis of generalization of experimental data and various assumptions to simplify engineering calculations. The article presents the results of theoretical and experimental studies of the mathematical model of the consolidation process of a water-saturated porous medium. This model is based on simplifying assumptions that are different from those adopted in well-known solutions. A fundamental approach to the formation of the model was developed on the basis of the kinetic representations of chemical reactions used in solving the environmental problems of epoxidation reactions of olefins. We determined the parameters of the mathematical model of the consolidation process of the saturated porous medium of clayey soil and confirmed its adequacy by the research results. In addition, we established the parameters of the field of non-equilibrium filtration, reducing the nonexistent ability of water-saturated soils.

scholarly journals A MULTIDIMENSIONAL SUBDIFFUSION MODEL WITH CHEMOTAXIS

2019 ◽  
Vol 11 (2) ◽  
pp. 1
Author(s):  
Bambang Hendriya Guswanto
Keyword(s):  
Mathematical Model ◽  
Probability Measure ◽  
Random Walks ◽  
Unit Ball ◽  
Dimensional Case ◽  
One Dimensional ◽  
The One ◽  
The Mathematical Model

The mathematical model for subdiffusion process with chemotaxis proposed by Langlands and Henry [1] for the one-dimensional case is extended to the multi-dimensional case. The model is derived from random walks process using a probability measure on a n-multidimensional unit ball $S^{n-1}$.

scholarly journals Prediction of Al2O3 leaching recovery in the Bayer process using statistical multilinear regresion analysis

2010 ◽  
Vol 46 (2) ◽  
pp. 161-169 ◽  
Author(s):  
I. Djuric ◽  
P. Djordjevic ◽  
I. Mihajlovic ◽  
Dj. Nikolic ◽  
Z. Zivkovic
Keyword(s):  
Mathematical Model ◽  
Bayer Process ◽  
Alumina Production ◽  
Statistical Reliability ◽  
Leaching Process ◽  
Input Parameters ◽  
Statistical Sample ◽  
One Year ◽  
The One ◽  
The Mathematical Model

This paper presents the results of defining the mathematical model which describes the dependence of leaching degree of Al2O3 in bauxite from the most influential input parameters in industrial conditions of conducting the leaching process in the Bayer technology of alumina production. Mathematical model is defined using the stepwise MLRA method, with R2 = 0.764 and significant statistical reliability - VIF<2 and p<0.05, on the one-year statistical sample. Validation of the acquired model was performed using the data from the following year, collected from the process conducted under industrial conditions, rendering the same statistical reliability, with R2 = 0.759.

Study on Hydraulic Energy-Recovering Workover Rig and the Simulation for Lifting the Pipestring

2006 ◽  
Vol 129 (2) ◽  
pp. 96-101 ◽  
Author(s):  
Zhang Lujun
Keyword(s):  
Mathematical Model ◽  
Potential Energy ◽  
Energy Saving ◽  
Simulation Analysis ◽  
Actual Measurement ◽  
Measurement Results ◽  
Vessel Volume ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Special Working

In this paper, an advanced energy-saving petroleum machinery, the hydraulic energy-recovering workover rig, is researched. The equipped power of this rig is only one third of an ordinary rig, and this rig can also recover and reuse the potential energy which is released by the pipestring when lowered. The special working theory of this rig is introduced. An energy-saving analysis is conducted. Analysis shows that when lowering the pipestring which weighs 260kN, the energy recovered by this rig is about 240×106J. The mathematical model of lifting the pipestring is established and a simulation analysis is conducted. Through simulation, some conclusions are obtained: (1) the lighter the pipestring the shorter the pipestring lifting time; (2) the smaller the throttle valve path area the longer the pipestring lifting time; (3) the smaller the air vessel volume the shorter the pipestring lifting time. The actual measurement results prove that the simulation results are right.

scholarly journals Aluminum bar cutting optimization for door and window manufacturing

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 155-162
Author(s):  
Ageu Araujo Machado ◽  
João Carlos Zayatz ◽  
Marcos Meurer Da Silva ◽  
Guilherme Melluzzi Neto ◽  
Gislaine Camila Lapasini Leal ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Real Data ◽  
Raw Material ◽  
Process Efficiency ◽  
Computational Time ◽  
Advantages And Disadvantages ◽  
Key Factor ◽  
Material Procurement ◽  
The One ◽  
The Mathematical Model

This study aims to optimize the one-dimensional cutting process of aluminum bars for the production of aluminum doors. Reducing the use of bars and the amount of material that becomes scrap is a key factor in process efficiency, reducing the need for raw material procurement. The mathematical model used considers the size of the bar, the number and size of cuts, the size of the leftovers that can be used and the size of the leftovers that are considered scrap. Based on real data from a company in the aluminum frame segment, the mathematical model was used to simulate three different scenarios. Three different objective functions were used in the simulations, and the results obtained in each scenario were described in order to indicate the advantages and disadvantages of using each objective function. For the instance sizes studied, the model is able to obtain optimal solutions with little computational time.

A study on the key techniques of application of REVO five-axis system in non-orthogonal coordinate measuring machine

2016 ◽  
Vol 231 (4) ◽  
pp. 730-736 ◽  
Author(s):  
Haitao Zhang ◽  
Shugui Liu ◽  
Xinghua Li
Keyword(s):  
Mathematical Model ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Coordinate Measuring Machines ◽  
Measurement Results ◽  
Measuring Machine ◽  
Key Techniques ◽  
Five Axis ◽  
The Mathematical Model ◽  
Body Theory

REVO five-axis system, designed for the orthogonal coordinate measuring machines, must be reconfigured for the application in the non-orthogonal coordinate measuring machines. First, in this article, error sources of the system and components of measurement data are analyzed; then, scale values of coordinate measuring machine axes, which are essential to derive the coordinates of measured points in non-orthogonal coordinate measuring machine, are separated out. Besides, the mathematical model of REVO is established based on the quasi-rigid body theory, from which the measurement results can be evaluated by data derived instead of that returned by the system. The effectiveness of both separation of scale values and mathematical model of REVO is proved by experiments and practice. The research of this article is of great significance to the application of REVO five-axis system in the non-orthogonal coordinate measuring machine.

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