scholarly journals Recent Advances in Elongational Flow Dominated Polymer Processing Technologies

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1792
Author(s):  
Zhongke Yuan ◽  
Xiaochuan Chen ◽  
Dingshan Yu
Keyword(s):  
Elongational Flow ◽  
Polymer Processing ◽  
Product Performance ◽  
New Method ◽  
New Techniques ◽  
Processing Technologies ◽  
Recent Advances ◽  
Eccentric Rotor ◽  
Material Systems ◽  
Processing Techniques

The continuous development of plasticizing conveying methods and devices has been carried out to meet the needs of the polymer processing industry. As compared to the conventional shear-flow-dominated plasticizing and conveying techniques, a new method for processing polymers based on elongational flow was proposed. This new method and the related devices such as vane extruders, eccentric rotor extruders and so on, exhibited multiple advantages including shorter processing time, higher mixing effectiveness, improved product performance and better adaptability to various material systems. The development of new techniques in the field of polymer material processing has opened up a broad space for the development of new plastic products, improved product performance and reduced processing costs. In this review, recent advances concerning the processing techniques based on elongational flow are summarized, and the broad applications in polymer processing as well as some future opportunities and challenges in this vibrant area are elucidated in detail.

scholarly journals An Effective Interface Tracking Method for Simulating the Extrudate Swell Phenomenon

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1305
Author(s):  
Ahmad Fakhari ◽  
Željko Tukovic ◽  
Olga Sousa Carneiro ◽  
Célio Fernandes
Keyword(s):  
Interpolation Method ◽  
Polymer Processing ◽  
Free Surface Flows ◽  
Interface Tracking ◽  
Extrudate Swell ◽  
Support Design ◽  
Point Interpolation Method ◽  
Point Interpolation ◽  
Flowing Material ◽  
Processing Techniques

The extrudate swell, i.e., the geometrical modifications that take place when the flowing material leaves the confined flow inside a channel and moves freely without the restrictions that are promoted by the walls, is a relevant phenomenon in several polymer processing techniques. For instance, in profile extrusion, the extrudate cross-section is subjected to a number of distortions that are motivated by the swell, which are very difficult to anticipate, especially for complex geometries. As happens in many industrial processes, numerical modelling might provide useful information to support design tasks, i.e., to allow for identifying the best strategy to compensate the changes promoted by the extrudate swell. This study reports the development of an improved interface tracking algorithm that employs the least-squares volume-to-point interpolation method for the grid movement. The formulation is enriched further with the consistent second-order time-accurate non-iterative Pressure-Implicit with Splitting of Operators (PISO) algorithm, which allows for efficiently simulating free-surface flows. The accuracy and robustness of the proposed solver is illustrated through the simulation of the steady planar and asymmetric extrudate swell flows of Newtonian fluids. The role of inertia on the extrudate swell is studied, and the results that are obtained with the newly improved solver show good agreement with reference data that are found in the scientific literature.

Overview of Containerless Processing Technologies

1981 ◽  
Vol 9 ◽  
Author(s):  
M. Barmatz
Keyword(s):  
Space Shuttle ◽  
Physical Contact ◽  
Materials Processing ◽  
Containerless Processing ◽  
Processing Technologies ◽  
Air Jets ◽  
Developmental Progress ◽  
Processing Techniques ◽  
And Control ◽  
Near Future

ABSTRACTIn the near future, a large segment of the scientific community will have an opportunity to perform materials processing experiments on the Space Shuttle in the reduced gravity environment of space. Many of these experiments will require containerless processing techniques that provide manipulation and control of weightless (molten) materials without physical contact with container walls or other holding devices. A variety of containerless processing technologies are now being developed for space and ground-based materials processing facilities. The utilization of air jets or high intensity acoustic, electromagnetic or electrostatic fields can produce forces that support and manipulate materials. Most of the present containerless research is directed toward the development of high temperature systems capable of melting and resolidifying materials. This paper will review the materials processing capabilities and level of developmental progress of each technique. An introduction to available NASA test facilities will also be given.

Ecocompositional and Performative Strategies for Creative Usage of Everyday Sounds: Creative Semantic Anchoring

Leonardo ◽  
2018 ◽  
Vol 51 (2) ◽  
pp. 195-196
Author(s):  
Damián Keller ◽  
Leonardo Feichas
Keyword(s):  
New Method ◽  
Creative Practice ◽  
Recent Advances ◽  
Solo Violin ◽  
Available Resources

The authors cover recent advances in ecologically grounded creative practice, highlighting performative strategies in instrumental writing. They address techniques adopted in ecocomposition and propose an expansion of the available resources by introducing a new method: creative semantic anchoring. The underlying concepts are presented and a case study—targeting the performative practice of Flausino Valle’s 26 Characteristic and Concert Preludes for Solo Violin—is described.

scholarly journals Recent Advances in Conversational Intelligent Tutoring Systems

AI Magazine ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 42-54 ◽  
Author(s):  
Vasile Rus ◽  
Sidney D’Mello ◽  
Xiangen Hu ◽  
Arthur Graesser
Keyword(s):  
Natural Language Processing ◽  
Natural Language ◽  
Language Processing ◽  
Intelligent Tutoring Systems ◽  
Intelligent Tutoring ◽  
Individual Student ◽  
Learning Progressions ◽  
Tutoring Systems ◽  
Recent Advances ◽  
Processing Techniques

We report recent advances in intelligent tutoring systems with conversational dialogue. We highlight progress in terms of macro and microadaptivity. Macroadaptivity refers to a system’s capability to select appropriate instructional tasks for the learner to work on. Microadaptivity refers to a system’s capability to adapt its scaffolding while the learner is working on a particular task. The advances in macro and microadaptivity that are presented here were made possible by the use of learning progressions, deeper dialogue and natural language processing techniques, and by the use of affect-enabled components. Learning progressions and deeper dialogue and natural language processing techniques are key features of DeepTutor, the first intelligent tutoring system based on learning progressions. These improvements extend the bandwidth of possibilities for tailoring instruction to each individual student which is needed for maximizing engagement and ultimately learning.

scholarly journals Optimization of Polymer Processing: A Review (Part I—Extrusion)

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 384
Author(s):  
António Gaspar-Cunha ◽  
José A. Covas ◽  
Janusz Sikora
Keyword(s):  
State Of The Art ◽  
Polymer Processing ◽  
Optimization Techniques ◽  
Practical Situation ◽  
Twin Screw Extruders ◽  
Extrusion Dies ◽  
Twin Screw ◽  
Processing Techniques ◽  
Screw Extruders ◽  
Modelling Approach

Given the global economic and societal importance of the polymer industry, the continuous search for improvements in the various processing techniques is of practical primordial importance. This review evaluates the application of optimization methodologies to the main polymer processing operations. The most important characteristics related to the usage of optimization techniques, such as the nature of the objective function, the type of optimization algorithm, the modelling approach used to evaluate the solutions, and the parameters to optimize, are discussed. The aim is to identify the most important features of an optimization system for polymer processing problems and define the best procedure for each particular practical situation. For this purpose, the state of the art of the optimization methodologies usually employed is first presented, followed by an extensive review of the literature dealing with the major processing techniques, the discussion being completed by considering both the characteristics identified and the available optimization methodologies. This first part of the review focuses on extrusion, namely single and twin-screw extruders, extrusion dies, and calibrators. It is concluded that there is a set of methodologies that can be confidently applied in polymer processing with a very good performance and without the need of demanding computation requirements.

What is the Sense of Life, and How Can We Study It? Review of the monograph: Sources of the sense of life. A new method of personality psychodiagnostics, by K.V Karpinskij

2021 ◽  
pp. 228-234
Author(s):  
V.A. Mazilov ◽  
Keyword(s):  
Meaning Of Life ◽  
Psychological Research ◽  
Diagnostic Techniques ◽  
New Method ◽  
Methodological Issues ◽  
New Techniques ◽  
Advantages And Disadvantages ◽  
The Subject ◽  
Diagnostic Research ◽  
Diagnostic Complex

The article is a review of the book "Sources of the meaning of life: a new method of personality psychodiagnostics" by the Belarusian psychologist K.V. Karpinskij. It is argued that the meaning of life became the subject of special psychological research only in the 20th century. In recent years, there have been many breakthroughs in this area, and undoubted progress is visible. There was a transition to the interpretation of the meaning of life as a systemic, that means, in other words, multicomponent and multilevel mental education. In his previous works K.V. Karpinskij subjected the problem of the psychology of the meaning of life to a comprehensive analysis. This book has no analogues among the observable thematic literature and contains new theoretical ideas, original methodological solutions and rich factual material, which together form a new look at the key methodological issues of the psychology of the meaning of life. First of all, this is a question about the subject and method of research. Despite the fact that the study of the psychology of the meaning of life is largely represented in foreign psychology, the author of the monograph consistently adheres to the methodology of Russian psychology. The book offers the author's methodology "Sources of the meaning of life", which was created with a full understanding of the advantages and disadvantages, opportunities and limitations of existing foreign analogues. Being a diagnostic complex in its composition, this technique has incorporated proven diagnostic techniques, as well as completely new techniques for studying the meaning of life. The methodology clearly surpasses the existing tools in its diagnostic (research) capabilities.

scholarly journals 3D Printing of Fibre-Reinforced Thermoplastic Composites Using Fused Filament Fabrication—A Review

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2188
Author(s):  
Andrew N. Dickson ◽  
Hisham M. Abourayana ◽  
Denis P. Dowling
Keyword(s):  
3D Printing ◽  
Polymer Composites ◽  
Mechanical Performance ◽  
Polymer Processing ◽  
Thermoplastic Composites ◽  
Fused Filament Fabrication ◽  
Compression Moulding ◽  
Processing Technologies ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Three-dimensional (3D) printing has been successfully applied for the fabrication of polymer components ranging from prototypes to final products. An issue, however, is that the resulting 3D printed parts exhibit inferior mechanical performance to parts fabricated using conventional polymer processing technologies, such as compression moulding. The addition of fibres and other materials into the polymer matrix to form a composite can yield a significant enhancement in the structural strength of printed polymer parts. This review focuses on the enhanced mechanical performance obtained through the printing of fibre-reinforced polymer composites, using the fused filament fabrication (FFF) 3D printing technique. The uses of both short and continuous fibre-reinforced polymer composites are reviewed. Finally, examples of some applications of FFF printed polymer composites using robotic processes are highlighted.

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