The Molecular Simulation Study of Optimum Blending Ratio for PVDF/PVC Membrane

2014 ◽  
Vol 968 ◽  
pp. 25-30
Author(s):  
Zhi Peng Zhao ◽  
Yue Feng Su ◽  
Mi Yi Li ◽  
Wen Sheng Deng
Keyword(s):  
Simulation Study ◽  
Mass Fraction ◽  
Sewage Treatment ◽  
Mean Square Displacement ◽  
Pvc Membrane ◽  
The Mean ◽  
Membrane Models ◽  
Solubility Coefficients ◽  
Cell Module ◽  
Dynamics Method

The PVDF/PVC blending membrane has a certain application in the field of sewage treatment. In this paper, the simulation study for the blending ratio of the PVDF/PVC membrane has been carried on, which has an influence on the membrane’s ability of sewage treatment. Firstly, the membrane models were constructed via Amorphous Cell module of MS (material studios) 6.0. Secondly, the optimization processes were achieved via Minimizer and MD (Molecular Dynamics) method of the Discover module. Lastly, the diffusion coefficients D was calculated indirectly through the Mean square displacement (MSD) getting from Forcite module and the solubility coefficients S was calculated indirectly through the adsorption isotherm getting from Sorption module. It was found that the membrane had a best ability of sewage treatment when the content of PVC was 5% (mass fraction). And the calculated result was well consistent with experiment result.

Behaviour of CO2-Polypropylene at Different Temperature Using Molecular Modelling Technique

2018 ◽  
Vol 775 ◽  
pp. 99-105
Author(s):  
Rahida Wati Sharudin ◽  
Muhammad Shafiq Shayuti ◽  
Nik Salwani Md Azmi
Keyword(s):  
Dynamic Simulation ◽  
Molecular Modelling ◽  
Low Cost ◽  
Mean Square Displacement ◽  
Spherical Shape ◽  
Crystalline Polymer ◽  
Expected Outcome ◽  
Higher Temperature ◽  
The Mean ◽  
Cell Module

Polypropylene is one of the most widely used plastics due to its desirable qualities such as low cost and its versatility. Polypropylene is also a semi-crystalline polymer where its properties and behaviour are affected by the thermal/mechanical properties during processing. The objective of this work is to predict the behaviour of CO2-polypropylene system at different temperature using dynamic simulation technique. Molecular modelling method has been extensively used by process simulators to forecast the expected outcome of certain processes. Cell containing CO2 and polypropylene were built using Amorphous Cell module and dynamic simulation was conducted using Forcite module with COMPASS II forcefield at 150, 155, 158 and 160°C using NVT ensemble. Molecular structuring was observed for the polypropylene after dynamic simulation where it formed a spherical shape. From the analysis, the mean square displacement (MSD) for the CO2 was the highest at 160°C. Higher MSD for CO2 in the system means that it is easier for the molecules to move into the system. The predicted diffusion coefficient CO2 also follows the trend of the MSD graph where it increases when the temperature increases. Higher temperature means that more energy was supplied to the system which made the molecules become kinetically energetic. Hence, the CO2 molecules tended to move to a wider area compared to the system with low temperature. Based on the result presented in this paper, it was concluded that molecular modelling was able to predict the behaviour of polypropylene in the presence of CO2 at various temperatures.

Interaction on Standard and Modified Adhesive (Albipox) with Water Using Molecular Modelling

2019 ◽  
Vol 797 ◽  
pp. 255-261 ◽  
Author(s):  
Rahida Wati Sharudin ◽  
Md Azmi Nik Salwani ◽  
Ahmad Zakiah
Keyword(s):  
Diffusion Coefficient ◽  
Molecular Modelling ◽  
Mean Square Displacement ◽  
Adhesive System ◽  
Water Molecules ◽  
Different Temperatures ◽  
Molecular Dynamic Technique ◽  
The Mean ◽  
Modified Epoxy ◽  
Cell Module

Molecular modelling method has been extensively used by process simulators to forecast the expected outcome of certain processes. The objective of this study is to predict the behavior of standard and modified epoxy resins with water using molecular dynamic technique. An arbitrary cell containing adhesive and water molecules was built using the Amorphous Cell Module and dynamic simulation was conducted using Forcite module at two different temperatures; 20 and 50°C for both standard and modified adhesive. From the analysis, the mean square displacement (MSD) for water molecules in a standard adhesive system was higher than Albipox which leads to a higher value of diffusion coefficient. Higher MSD for water in the system with standard adhesive means that it is easier for water molecules to move in the system. It moves to a wider or larger area compared to the water with Albipox in the system. This also shows that the usage of Albipox was successful to control the moisture uptake of water. The predicted diffusion coefficient of water also follows the trend of the experimental data where it increased when the temperature increased for both systems. Based on the result presented in this paper, it has been concluded that molecular modelling was able to predict the interaction of standard and modified adhesive with water.

Analysis and balance of phosphorous removal from wastewater at urban wastewater treatment plant

2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Phosphorus Recovery ◽  
Anaerobic Sludge ◽  
Biological Phosphorus Removal ◽  
The Mean

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.

scholarly journals Reconstruction of Diffusion Coefficients and Power Exponents from Single Lagrangian Trajectories

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 111
Author(s):  
Leonid M. Ivanov ◽  
Collins A. Collins ◽  
Tetyana Margolina
Keyword(s):  
Black Sea ◽  
Diffusion Coefficients ◽  
Current System ◽  
Mean Square Displacement ◽  
California Current ◽  
The Black Sea ◽  
Mean Square ◽  
California Current System ◽  
The Mean ◽  
Non Gaussian

Using discrete wavelets, a novel technique is developed to estimate turbulent diffusion coefficients and power exponents from single Lagrangian particle trajectories. The technique differs from the classical approach (Davis (1991)’s technique) because averaging over a statistical ensemble of the mean square displacement (<X2>) is replaced by averaging along a single Lagrangian trajectory X(t) = {X(t), Y(t)}. Metzler et al. (2014) have demonstrated that for an ergodic (for example, normal diffusion) flow, the mean square displacement is <X2> = limT→∞τX2(T,s), where τX2 (T, s) = 1/(T − s) ∫0T−s(X(t+Δt) − X(t))2 dt, T and s are observational and lag times but for weak non-ergodic (such as super-diffusion and sub-diffusion) flows <X2> = limT→∞≪τX2(T,s)≫, where ≪…≫ is some additional averaging. Numerical calculations for surface drifters in the Black Sea and isobaric RAFOS floats deployed at mid depths in the California Current system demonstrated that the reconstructed diffusion coefficients were smaller than those calculated by Davis (1991)’s technique. This difference is caused by the choice of the Lagrangian mean. The technique proposed here is applied to the analysis of Lagrangian motions in the Black Sea (horizontal diffusion coefficients varied from 105 to 106 cm2/s) and for the sub-diffusion of two RAFOS floats in the California Current system where power exponents varied from 0.65 to 0.72. RAFOS float motions were found to be strongly non-ergodic and non-Gaussian.

scholarly journals Subdiffusive Reaction Model of Molecular Species in Liquid Layers: Fractional Reaction-Telegraph Approach

2021 ◽  
Vol 5 (2) ◽  
pp. 51
Author(s):  
Ashraf M. Tawfik ◽  
Mohamed Mokhtar Hefny
Keyword(s):  
Molecular Species ◽  
Transport Model ◽  
Mean Square Displacement ◽  
Telegraph Equation ◽  
Reaction Model ◽  
Simulation Techniques ◽  
Experimental Works ◽  
The Mean ◽  
Classical Transport ◽  
Fractional Reaction

In recent years, different experimental works with molecular simulation techniques have been developed to study the transport of plasma-generated reactive species in liquid layers. Here, we improve the classical transport model that describes the molecular species movement in liquid layers via considering the fractional reaction–telegraph equation. We have considered the fractional equation to describe a non-Brownian motion of molecular species in a liquid layer, which have different diffusivities. The analytical solution of the fractional reaction–telegraph equation, which is defined in terms of the Caputo fractional derivative, is obtained by using the Laplace–Fourier technique. The profiles of species density with the mean square displacement are discussed in each case for different values of the time-fractional order and relaxation time.

Molecular Dynamics Study of Microscopic Mechanism of Diffusion in Li2SiO3 System

1991 ◽  
Vol 46 (7) ◽  
pp. 616-620 ◽  
Author(s):  
Junko Habasaki
Keyword(s):  
Molecular Dynamics ◽  
Coordination Number ◽  
Md Simulation ◽  
Mean Square Displacement ◽  
Mean Square ◽  
Lithium Ions ◽  
Microscopic Mechanism ◽  
Trapping Model ◽  
The Mean

MD simulation has been performed to learn the microscopic mechanism of diffusion of ions in the Li2SiO3 system. The motion of lithium ions can be explained by the trapping model, where lithium is trapped in the polyhedron and moves with fluctuation of the coordination number. The mean square displacement of lithium was found to correlate well with the net changes in coordination number.

THE EFFECT OF PREMELTING: STUDY FOR SEMI-INFINITE CRYSTALS AND NANO-SYSTEMS

1994 ◽  
Vol 08 (24) ◽  
pp. 3411-3422 ◽  
Author(s):  
W. SCHOMMERS
Keyword(s):  
Pair Correlation ◽  
Mean Square Displacement ◽  
Phonon Density ◽  
Mean Square ◽  
Phonon Density Of States ◽  
Molecular Dynamics Calculations ◽  
Theory Of Melting ◽  
The Mean ◽  
Dynamical Properties ◽  
Reliable Interaction

The effect of premelting is of particular interest in connection with the theory of melting. In this paper, we discuss the structural and dynamical properties of the surfaces of semi-infinite crystals as well as of nano-clusters, which show the effect of premelting. The investigations are based on molecular-dynamics calculations: different models are used for the systematic study of the effect of premelting. In particular, the behaviour of the following functions have been studied: pair correlation function, generalized phonon density of states, and the mean-square displacement as a function of time. The calculations have been done for krypton since for this substance a reliable interaction potential is available.

scholarly journals Kajian Pemanfaatan Silika dari Sekam Padi dalam Pengolahan Limbah Tekstil

2017 ◽  
Vol 1 ◽  
pp. 60
Author(s):  
Isma Masrofah
Keyword(s):  
Rice Husk ◽  
Textile Industry ◽  
Waste Treatment ◽  
Rapid Development ◽  
Sewage Treatment ◽  
Green Manufacturing ◽  
Pvc Membrane ◽  
Textile Waste ◽  
Rice Husk Silica ◽  
Washing Process

Abstract – Textile industry is one of the waste contamination industries that can pollute the environment, so that the rapid development of textile industry must be followed by the improvement of its sewage treatment system. Along with the global issue of Green Manufacturing, the textile industry waste treatment can promote environmentally friendly waste treatment process and derived from renewable substances. Therefore, it is necessary to study the utilization of rice husk silica in the processing of textile waste. The results of the study provide information that textile wastes come from all processes in the textile industry, from pretreatment to finishing. Rice husk ash silica is a material utilized adsorption of textile waste or mixture of PolyVinylChloride (PVC) membrane material to filter textile waste. The characteristics of rice husk silica are influenced by the extraction method. The initial washing process using acid and then combustion at 600 ° C - 750 ° C produces a relatively high purity of silica with a maintained silica amorphous level.Keywords: Rice Husk Silica, Textile Waste, Textile Waste Processing, Silica Characteristic

Cooling rate dependence of solidification for liquid aluminium: a large-scale molecular dynamics simulation study

2016 ◽  
Vol 18 (26) ◽  
pp. 17461-17469 ◽  
Author(s):  
Z. Y. Hou ◽  
K. J. Dong ◽  
Z. A. Tian ◽  
R. S. Liu ◽  
Z. Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Cooling Rate ◽  
Simulation Study ◽  
Large Scale ◽  
Solidification Process ◽  
Molecular Dynamics Method ◽  
Dynamics Simulation ◽  
Liquid Aluminium ◽  
Dynamics Method

The effect of the cooling rate on the solidification process of liquid aluminium is studied using a large-scale molecular dynamics method.

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