scholarly journals Simulation of a single-stage evaporator system integrated with a mechanical vapor compressor for concentrating the electrolytic system KNO3 – H2O

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Ervin Karic ◽  
Rejhá Alic
Keyword(s):  
Mathematical Model ◽  
Temperature Difference ◽  
Salt Content ◽  
Industrial Process ◽  
Single Stage ◽  
Average Temperature ◽  
Mean Temperature ◽  
Heating Steam ◽  
The Impact ◽  
The Mathematical Model

A simulation of a single-stage evaporator system integrated with a mechanical com- pressor for a case study (concentrating the electrolytic system KNO3 – H2O) was performed. A mathematical model of the subsystem of a single-stage evaporator, a mechanical compressor, and superheated steam seeding is presented. Microsoft Excel with VBA (Visual Basic for Application) was used to solve the mathematical model. The model was solved by an iterative method where the values of the in- let stream temperature and the salt concentration in the concentrated stream at the evaporator outlet were assumed. The process parameters of the system have been determined. Since the goal of any industrial process is to minimize costs and maximize products, the impact of mean temperature difference changes on satu- ration water consumption and molar salt content in the concentrated stream was presented. 106.92 kg/h of freshwater are required to obtain 18% by weight of salt in a concentrated stream, while 432.30 kg/h of fresh water are required to obtain 25% by weight of salt in a concentrated stream. Consumption of heating steam ranged from 1760.31 to 4473.4 kg/h depending on the average temperature dif- ference. By increasing the temperature differences from 10 to 25 ◦C, the amount of transferred upper lines increases from 1025 to 2750 kW, which is an advantage of increasing the mean temperature difference. The disadvantage of the larger tem- perature difference is the increase in the power of the mechanical compressor from 97.02 to 384.12 kW.

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.

The Impact Analysis of Revolute Pair Clearance to the End Pose Accuracy of Welding Robot

2015 ◽  
Vol 778 ◽  
pp. 259-263
Author(s):  
Fa Jun Zhang ◽  
Lin Zi Li ◽  
Hui Lin ◽  
Yin Lin Pu ◽  
Zhu Xin
Keyword(s):  
Mathematical Model ◽  
Impact Analysis ◽  
Joint Clearance ◽  
Welding Robot ◽  
Movement Characteristic ◽  
Movement Stability ◽  
Simulation Results ◽  
The Impact ◽  
The Mathematical Model ◽  
Welding Position

Various uncertain factors affect the movement of the welding robot, thus welding gun tend to deviate from the theory of welding position which reduces the welding accuracy, of which the revolute pair clearance have an greater effect on the movement of the welding robot. In order to study the influence of revolute pair clearance to the end pose accuracy of welding robot, the mathematical model of revolute pair clearance was established, and the software SolidWorks was used for establishing the welding robot model, making simulations of the mechanical arm with joint clearance and no joint clearance. At last, the movement characteristic of the hinge shaft is attained. The simulation results showed that the shaft velocity and displacement of mechanical arm with joint clearance has a certain degree of fluctuation, which affecting the end pose accuracy of welding robot , and reducing the movement stability and the welding accuracy of welding robot.

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 NECESSITY TO IMPROVE THE MATHEMATICAL MODEL OF FREIGHT CARS TO STUDY CASES OF ITS DERAILMENTS

2020 ◽  
pp. 442-451
Author(s):  
А.V. Batig ◽  
A. Ya. Kuzyshyn
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Computer Experiment ◽  
Rolling Stock ◽  
Software Systems ◽  
Freight Car ◽  
The Stability ◽  
The Many ◽  
The Impact ◽  
The Mathematical Model

One of the most important problems that pose a serious threat to the functioning of railways is the problem of freight cars derailment. However, according to statistics, the number of cases of the derailments of freight cars in trains annually grows. Тo prevent such cases, the necessary preventive measures are developed, and to study the causes of their occurrence, a significant number of mathematical models, programs and software systems created by leading domestic and foreign scientists. Studies of such mathematical models by the authors of this work have led to the conclusion that they are not sufficiently detailed to the extent that it is necessary for analyze the reasons of its derailment. At the same time, an analysis of the causes of the rolling stock derailments on the railways of Ukraine over the past five years showed that in about 20 % of cases they are obvious, and in 7 % of cases they are not obvious and implicitly expressed. The study of such cases of rolling stock derailment during an official investigation by the railway and during forensic railway transport expertises requires the use of an improved mathematical model of a freight car, which would allow a quantitative assessment of the impact of its parameters and rail track on the conditions of railway accidents. Therefore, taking into account the main reasons that caused the occurrence of such railroad accidents over the last five years on the railways of Ukraine, the article selected the main directions for improving the mathematical model of a freight car, allowing to cover all the many factors (explicit and hidden) and identify the most significant ones regarding the circumstances of the derailment rolling stock off the track, established on the basis of a computer experiment. It is proposed in the mathematical model of a freight car to take into account the guiding force, the value of which is one of the main indicators of the stability of the rolling stock. The authors of the article noted that not taking into account the influence of the guiding forces on the dynamics of the freight car can lead to an erroneous determination of the reasons for the rolling stock derailment or even to the impossibility of establishing them.

DIVERSITY AND KNOWLEDGE SHARING IN CONSTRUCTION: A MATHEMATICAL MODEL

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Daoud Kiomjian ◽  
F. Jordan Srour ◽  
Issam Srour
Keyword(s):  
Mathematical Model ◽  
Knowledge Sharing ◽  
Five Dimensions ◽  
Agent Based ◽  
Language And Education ◽  
And Performance ◽  
Demographic Attributes ◽  
Future Work ◽  
The Impact ◽  
The Mathematical Model

Conventional wisdom in the management literature holds that diversity is positively correlated with performance. Yet, the findings from the construction field indicate that this is not always the case. In an effort to study the interaction between diversity and performance in the construction industry, this paper presents the elements of a theoretical mathematical model to explore the relationship between diversity and knowledge sharing which is a precursor of performance. This model includes five dimensions of diversity: ethnicity, age, experience, language and education. At the heart of the mathematical model is a fuzzy based system that generates the probability of knowledge sharing among members with different demographic attributes. The presented fuzzy system will, in future work, become the foundation of an agent based model used to study the impact of worker interactions on productivity.

Performance Analysis of Parallel Feed LT-MED Desalination System with Thermal Vapor Compressor

2011 ◽  
Vol 347-353 ◽  
pp. 3058-3063 ◽  
Author(s):  
Xiao Hua Liu ◽  
Guo Jian Cao ◽  
Sheng Qiang Shen ◽  
Guang Bin Zhao
Keyword(s):  
Mathematical Model ◽  
Flow Resistance ◽  
Tube Bundle ◽  
Steam Temperature ◽  
Heating Steam ◽  
Temperature Loss ◽  
Output Ratio ◽  
Actual Operation ◽  
The Cost ◽  
The Mathematical Model

This paper presents a theoretical analysis on parallel feed LT-MED desalination system with thermal vapor compressor which is helpful to the design and operation of such kind of seawater desalination plant. The mathematical model of a parallel feed LT-MED desalination system with thermal vapor compressor (TVC) is developed on the basis of the mass and energy conservation equations. In the model, the temperature loss is considered caused by the boiling point elevation (BPE) of seawater and the steam flow resistance is also included caused by flowing through tube bundle demisters and pipelines between adjacent evaporators. The property parameters of seawater are taken as the functions of temperature and concentration. A computer program is drawn up to solve the mathematical model. The calculation is based on the system with rated water production 3000 t/d. Taking actual operation into account, the influence of heating steam temperature of the first effect and entrained steam position of TVC on system performance are analyzed. The results show that when other relative parameters are fixed, the gained output ratio (GOR) and the total area of evaporators change slightly with the increasing of the heating steam temperature of first effect under the calculation condition of this paper. The results also demonstrate that there exist suitable entrained steam positions of TVC for the cost of water.

Numerical Analysis of Heat and Mass Transfer Performance of the Packed-Type Parallel Flow Dehumidifier

2014 ◽  
Vol 989-994 ◽  
pp. 3100-3104
Author(s):  
Rui Hang Zhang ◽  
Zi Ye Wang ◽  
Run Ping Niu
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Parallel Flow ◽  
Transfer Performance ◽  
Transfer Coefficients ◽  
Simulation Results ◽  
Set Up ◽  
The Impact ◽  
The Mathematical Model

TA mathematical model describing heat and mass transfer performance of packed-type parallel flow dehumidifier was set up. The numerical solution of differential equations was derived. Taking the heat and mass transfer coefficients obtained by experiments as the input parameters of the model, the impact of solution inlet parameters on outlet parameter of air was described. The simulation results indicated that the mathematical model could be used to predict the performance of liquid dehumidification. The results showed that the mathematical model can be of great value in the design and improvement of dehumidifier.

The Parameters Calibration and Error Compensation of Circular Gratings for Parallel Double-Joint Coordinate Measuring Machine (CMM)

2011 ◽  
Vol 105-107 ◽  
pp. 1899-1902 ◽  
Author(s):  
Xiao Wei Zhang ◽  
Xing Hua Li ◽  
Bo Chen
Keyword(s):  
Mathematical Model ◽  
Measurement Error ◽  
Curve Fitting ◽  
Error Compensation ◽  
Coordinate Measuring Machine ◽  
Measuring Machine ◽  
Circular Grating ◽  
The Impact ◽  
The Mathematical Model ◽  
Main Factor

In this paper, the mathematical model with errors for parallel double-joint coordinate measuring machine (CMM) was proposed. The main factor of the impact of circular grating measurement error--radial install eccentric error--was analyzed. The error was measured and the data obtained from measurement was used to curve fitting and form the error compensation formula. Experiments show that the method of error compensation has good usability and accuracy.

scholarly journals Probabilistic Analysis for Estimation of the Initiation Time of Corrosion

2019 ◽  
Vol 15 (2) ◽  
pp. 1-13
Author(s):  
Wafa Nor El Houda Cherifi ◽  
Youcef Houmadi ◽  
Omar Benali
Keyword(s):  
Mathematical Model ◽  
Probability Distribution ◽  
Distribution Functions ◽  
Initiation Time ◽  
Probabilistic Design ◽  
Statistical Parameters ◽  
Probability Distribution Functions ◽  
Probabilistic Study ◽  
The Impact ◽  
The Mathematical Model

Abstract In this paper, a probabilistic study on durability concrete was carried out. In such a design, initiation time of corrosion must be expressed as a mathematical model using Fick’s second law and the statistical distributions properties of theirs parameters was included in this model. The scatter both in the environmental exposure conditions and structural properties was considered as random fields in the mathematical model with a probabilistic design. The main objective of this study is predicted initiation time of corrosion of concrete structures in chloride containing environments. This probabilistic study is developed using Monte Carlo simulation to determine the contribution of each input parameters and the statistical parameters of the random variables on the probability distribution functions of the initiation time of corrosion. Also, a comparison study was carried out to analyze the impact of the probability distribution on the response (the initiation time of corrosion).

scholarly journals Melacak Dampak Perubahan Iklim Terhadap Kondisi Makroekonomi dengan Teori Permainan Dinamis

2018 ◽  
Vol 7 (2) ◽  
pp. 57-62
Author(s):  
Muhammad Wakhid Musthofa
Keyword(s):  
Climate Change ◽  
Economic Growth ◽  
Mathematical Model ◽  
Equation System ◽  
Output Function ◽  
Macroeconomic Conditions ◽  
System A ◽  
Economic Growth Model ◽  
The Impact ◽  
The Mathematical Model

Makalah ini membahas tentang model matematika dampak perubahan iklim terhadap kondisi makroekonomi suatu negara. Dengan mengacu pada model pertumbuhan ekonomi endogen pada suatu negara, dengan fungsi output berbentuk fungsi Cobb-Douglas akan diturunkan model matematika yang mendeskripsikan dampak perubahan iklim terhadap kondisi makroekonomi suatu negara. Selanjutnya, akan dikonstruksikan pula fungsi ongkos yang berhubungan dengan model matematika yang telah diturunkan. Mengingat model matematika tersebut masih dalam bentuk sistem persamaan nonlinear, maka diperlukan proses linearisasi untuk menghasilkan model matematika yang linear sehingga memudahkan untuk dianalisis maupun diaplikasikan. [This paper discusses the mathematical model of the impact of climate change on the macroeconomic conditions of a country. By referring to an endogenous economic growth model in a country, with the output function in the form of a Cobb-Douglas function, a mathematical model will be described that describes the effects of climate change on the macroeconomic conditions of a country. Furthermore, it will also construct cost functions related to mathematical models that have been derived. Considering that the mathematical model is still in the form of a nonlinear equation system, a linearisation process is needed to produce a linear mathematical model that makes it easy to analyze and apply.]

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