scholarly journals The Research on Modeling and Simulation of TFE Polymerization Process

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Jing Gao Sun ◽  
Qin Cao
Keyword(s):  
Emulsion Polymerization ◽  
Research Work ◽  
Operating Conditions ◽  
Polymerization Process ◽  
Chain Polymer ◽  
Related Data ◽  
Simulation Based ◽  
Suitable Amount ◽  
Semibatch Reactor ◽  
The Impact

PTFE (polytetrafluoroethylene) is the fluorinated straight-chain polymer, made by the polymerization of tetrafluoroethylene monomer; it is used widely because of its excellent performance and can be obtained by the polymerization of body, solutions, suspensions, and emulsions. But only the last two are the main ways. This research paper makes simulation based on Polymer Plus. It uses the emulsion polymerization method at background to carry out a semibatch reactor system. Upon the actual production conditions, simulation process under the steady state conditions is used to analyze the effects of the changes on operating conditions; the corresponding dynamic model is created to analyze the impact of the changes of conditions on the entire system. Moreover, the amount of APS which plays an important part in this reaction is discussed for getting the most suitable amount of initiator. Because of less research work on this job, it is so difficult to find the related data from the literature. Therefore, this research will have a great significance for the process of the tetrafluoroethylene emulsion polymerization in the future.

scholarly journals Optimization and Modeling of an Emulsion Polymerization Reactor

2021 ◽  
Author(s):  
Narges Ghadi
Keyword(s):  
Emulsion Polymerization ◽  
Water Solubility ◽  
Monomer Conversion ◽  
High Water ◽  
Oscillatory Behavior ◽  
Operating Conditions ◽  
Polymer Properties ◽  
Continuous Polymerization ◽  
Simulation Results ◽  
The Impact

A mathematical model was developed to simulate emulsion polymerization in batch, semi-batch and continuous reactors for monomers with high water solubility and significant desorption such as vinyl acetate. The effects of operating conditions such as initiator and emulsifier concentration as well as reactor temperature have been studied. The simulation results revealed the sensitivity of polymer properties and monomer conversion to variation of these operating conditions. Furthermore, the impact of monomer soluble impurities on reduction of monomer conversion has been investigated. In order to control polymer molecular weight, application of chain transfer agents such as t-nonyl mercaptan was suggested. Generally, the simulation results fitted well [with] experimental data from the literature. Several optimizing policies were considered to enhance the reaction operation for better product quality. During continuous polymerization, the reactor demonstrates oscillatory behavior throughout the operation. A new reactor train configuration was consistent with the aim of damping the oscillations and producing high-quality latex.

scholarly journals Synthesis of polar copolymers by the process of emulsion via free radicals (FRP)

2019 ◽  
pp. 1-5
Author(s):  
Luis Mario Magaña-Maldonado ◽  
David Contreras-López
Keyword(s):  
Free Radicals ◽  
Batch Reactor ◽  
Operating Conditions ◽  
Polymerization Process ◽  
Optimal Operating ◽  
Molecular Weights ◽  
Polymer Industry ◽  
The Impact ◽  
Vinyl Propionate

At present, the polymer industry has gained increasing importance due to the versatility of its properties, as well as the impact they have on the environment. The present investigation provides the determination of optimal operating conditions for the polymerization of styrene and vinyl propionate in a Batch reactor, as well as the copolymerization of styrene with propionate monomers by the process of emulsion via free radicals, allowing to observe the variations with respect to Reaction yields and molecular weights. Another important factor is the activation of the initiator so that the polymerization process begins within each of the micelles. Likewise, it was found that, in the copolymerizations, there are considerable variations with respect to reaction yields and molecular weights as the concentrations are modified. In addition, it was found that there are higher yields in styrene polymerizations per solution than emulsion.

Nacelle: Air Intake Aerodynamic Design and Inlet Compatibility

2014 ◽  
Author(s):  
Jingjing Chen ◽  
Yadong Wu ◽  
Zhonglin Wang ◽  
Anjenq Wang
Keyword(s):  
Research Work ◽  
Operating Conditions ◽  
Pressure Recovery ◽  
Weighting Coefficient ◽  
Maximum Pressure ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Induction System ◽  
Air Intake ◽  
The Impact

One of the most challenging operating conditions to be certified for FAR33 & FAR25 requirements is ground crosswind condition. When “Engine” is operated using the designed inlet and nacelle, within the flight envelope, could accommodate inlet separation/distortion resulted from crosswind and high angle-of-attack operating conditions. Inlet flow separation and distortion could trigger fan or core stall, as well as induce high fan and/or engine vibrations. The air induction system or inlet of the engine is designed to provide velocity and pressure distributions with minimum distortion and maximum pressure recovery to the propulsion system. Engine-inlet-airframe compatibility is one of the major tasks required to be evaluated in detail during the engine developing phase. This research is a parametric study of using CFD to evaluate operational characteristics of the air induction system. Comparisons of various inlet designs are made and characterized into three categories, i.e., i) Inlet flow recovery, ii) Inlet flow distortion, iii) Inlet Mach distribution. The objective is to assess the impact of air induction design of turbofan upon inlet compatibility. The current research work includes four parts, i.e., i) A geometry modeling process of nacelle, inlet, wing and fuselage, ii) A meshes generator ICEM, iii) The ANSYS CFX CFD software which could achieves numerical simulation and post-processing, iv) The Matlab platform with the function of coupling all considerations listed above for inlet compatibility optimization, based on genetic algorithm and Kriging agent model. The research introduces the Kriging model and weighting coefficient to optimize total pressure loss coefficient and static pressure recovery coefficient, with the external nacelle flow ignored. Bezier equation was used to fit the optimized curves obtained by changing two control points at the inter surface of nacelle. The wing-mounted model coupled with the nacelles, fuselage and wings was then built to make the assessment of inlet compatibility of air intake system relative to the isolate model. Comparison of aerodynamic performance was then made between the original and optimal nacelle, to show correlation between inlet compatibility and air intake profile.

scholarly journals Optimization and Modeling of an Emulsion Polymerization Reactor

2021 ◽  
Author(s):  
Narges Ghadi
Keyword(s):  
Emulsion Polymerization ◽  
Water Solubility ◽  
Monomer Conversion ◽  
High Water ◽  
Oscillatory Behavior ◽  
Operating Conditions ◽  
Polymer Properties ◽  
Continuous Polymerization ◽  
Simulation Results ◽  
The Impact

A mathematical model was developed to simulate emulsion polymerization in batch, semi-batch and continuous reactors for monomers with high water solubility and significant desorption such as vinyl acetate. The effects of operating conditions such as initiator and emulsifier concentration as well as reactor temperature have been studied. The simulation results revealed the sensitivity of polymer properties and monomer conversion to variation of these operating conditions. Furthermore, the impact of monomer soluble impurities on reduction of monomer conversion has been investigated. In order to control polymer molecular weight, application of chain transfer agents such as t-nonyl mercaptan was suggested. Generally, the simulation results fitted well [with] experimental data from the literature. Several optimizing policies were considered to enhance the reaction operation for better product quality. During continuous polymerization, the reactor demonstrates oscillatory behavior throughout the operation. A new reactor train configuration was consistent with the aim of damping the oscillations and producing high-quality latex.

scholarly journals Identification of HATE speech tweets in Pashto language using Machine Learning techniques

2021 ◽  
Vol 10 (3) ◽  
pp. 1501-1508
Keyword(s):  
Machine Learning ◽  
Social Media ◽  
Decision Tree ◽  
Sentiment Analysis ◽  
Hate Speech ◽  
Research Work ◽  
Machine Learning Techniques ◽  
Related Data ◽  
Learning Techniques ◽  
The Impact

From the last few years, researchers are very much attracted to sentiment analysis, especially towards hate speech detectionsystems. As in different languages procreation of hate speech has compelling and symbolic consideration on social media. Hate speech has a great impact on society, using hate words harms others dignity. Hate speech detectionsystems areimportant to stop the transformation of hate words into crimes. In this research,a frameworkis developedfor hate speech detectionsystemin the Pashto language. A datasetis created for which data is collected from Twitter. Because there is no related data available. Most of the research work has been done in this domain for other languages, and it’s very maturein the context of detecting hate speech. But when it arrives at the morphological languages not much work has been done especially in the Pashto language. This researchaimed and collected data from Twitter, Tweets related to ethnicity and religion. The data collected from twitter has been annotated manually and categorized the data as hate or not by comparing it with the offensive content. For hate speechdetection systemsto view the impact of different features/attribute this study performed experiments on the existing classifiers i.e.,SVM, Naïve Bayes, Decision tree and KNN. SVM produced the highest result at dataset of 500 i.e.,74% among all the classifiers. KNN and Decision Tree produced same result at dataset of 1500 i.e.,65.0%. Dataset of 2800 Decision Tree produced the highest result i.e.,72% and SVM produced 71.9%.

Experimental and modeling analysis on the optimization of combined VVT and EGR strategies in turbocharged direct-injection gasoline engines with VNT

2021 ◽  
pp. 095440702110045
Author(s):  
José Galindo ◽  
Héctor Climent ◽  
Joaquín de la Morena ◽  
David González-Domínguez ◽  
Stéphane Guilain ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Research Work ◽  
Optimization Procedure ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Intake Manifold ◽  
Engine Fuel ◽  
The Impact

The combination of a growing number of complex technologies in internal combustion engines (ICE) is commonplace, due to the need of complying with the tight pollutant regulations and achieving high efficiencies. Hence the work of calibration engineers is led by a constant increase in degrees of freedom in ICE design. In this research work, a wide analysis on the optimization of combined variable valve timing (VVT) and exhaust gases recirculation (EGR) strategies is developed, in order to reduce fuel consumption in a EURO 6 1.3l 4-stroke 4-cylinder, gasoline, turbocharged, direct-injection engine, also equipped with a variable nozzle turbine (VNT). For that purpose, a methodology which combines 1D engine simulations with limited experimental work was applied. First, the data from 25 experimental tests distributed into three steady engine operating conditions was used to calibrate a 1D model. Then, modeling parametric studies were performed to optimize VVT and EGR parameters. A total of 150 cases were simulated for each operating point, in which VVT settings and EGR rate were varied at iso-air mass flow and iso-intake manifold temperature. The optimization was based on finding the configuration of VVT and EGR systems which maximizes the indicated efficiency. All different cases modeled were also evaluated in terms of pumping and heat losses. Moreover, a deep assessment of instantaneous pressure traces and mass flows in intake and exhaust valves was given, to provide insights about the optimization procedure. Finally, the findings obtained by simulation were compared with the results from a design of experiments (DOE) composed of more than 300 tests, and the impact on engine fuel consumption was analyzed.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Truck Tire Operating Temperatures on Flat and Curved Test Surfaces

2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak
Keyword(s):  
Flat Surface ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Load Pressure ◽  
Truck Tire ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
The Impact ◽  
Tread Rubber ◽  
Cylindrical Test

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.

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