scholarly journals Selection of Polymer Materials for Micro Slide Bearings With Respect to Minimization of Resistance to Motion

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 78622-78629 ◽  
Author(s):  
Zbigniew Kusznierewicz ◽  
Marcin Michalowski ◽  
Sergiusz Luczak ◽  
Karol Baginski ◽  
Blazej Kabzinski ◽  
...  
Keyword(s):  
Polymer Materials ◽  
Selection Of

scholarly journals Dynamic covalent chemistry in polymer networks: a mechanistic perspective

2019 ◽  
Vol 10 (45) ◽  
pp. 6091-6108 ◽  
Author(s):  
Johan M. Winne ◽  
Ludwik Leibler ◽  
Filip E. Du Prez
Keyword(s):  
Physicochemical Properties ◽  
Reaction Mechanisms ◽  
Polymer Networks ◽  
Molecular Network ◽  
Polymer Materials ◽  
Dynamic Covalent Chemistry ◽  
Selection Of

A selection of dynamic chemistries is highlighted, with a focus on the reaction mechanisms of molecular network rearrangements, and on how mechanistic profiles can be related to the mechanical and physicochemical properties of polymer materials.

scholarly journals The use of polymer materials for medical applications

2020 ◽  
pp. 5-13
Author(s):  
D. M. Los' ◽  
V. M. Shapovalov ◽  
S. V. Zotov
Keyword(s):  
Cardiac Surgery ◽  
Medical Devices ◽  
Metabolic Pathways ◽  
Living Organism ◽  
Polymer Materials ◽  
Medical Applications ◽  
Allergic Reactions ◽  
Important Criterion ◽  
Practical Medicine ◽  
Selection Of

The article analyzes the use of polymer materials for solving problems of theoretical and practical medicine. The effectiveness of the use of polymers in reconstructive cardiac surgery, radiation therapy, etc. has been shown. The basic requirements set for polymers and composites for medical devices have been identified. The most important criterion for the selection of polymers is the safety of their use in clinical practice and their ability to biodegrade when they enter a living organism along the usual metabolic pathways in the absence of inflammatory and allergic reactions of surrounding tissues during longterm followup care.

scholarly journals A Case Study on the Selection of Materials for Eye Lenses

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Fehim Findik
Keyword(s):  
Polymer Materials ◽  
Materials Selection ◽  
Present Material ◽  
Environmental Friendly ◽  
Selection Of

A case study on the selection of materials for eye lenses is reported by means of Ashby's materials selection diagrams. In this study, 6 polymer materials of PMMA, PC, PS, PVC, PET, and PA are reviewed and their properties are found from the selection diagrams of Ashby and compared in a table. The final results confirmed that PMMA (acrylic) is the best material for eye lenses. The outcome also showed that the present material is environmental friendly being nontoxic and recyclable.

Fluorescence from Coated Oxide Nanoparticles

2001 ◽  
Vol 703 ◽  
Author(s):  
D. Vollath ◽  
I. Lamparth ◽  
D. V. Szabó
Keyword(s):  
Polymer Coating ◽  
Microwave Plasma ◽  
Polymer Materials ◽  
Narrow Particle Size Distribution ◽  
Oxide Nanoparticles ◽  
Additional Advantage ◽  
Ceramic Phase ◽  
Coated Nanoparticles ◽  
Sharp Emission Line ◽  
Selection Of

ABSTRACTIn many cases, coated nanoparticles behave like isolated ones. Using the microwave plasma process, it is possible to produce oxide nanoparticles with ceramic or polymer coating. Coating the particles has the additional advantage that by proper selection of the coating it is possible to suspend the particles in distilled water without using any colloid stabilizer. From quantum dots made of sulfides or selenides, it is well known from literature that fluorescence depends strongly on the coating of the kernels. In the case of CdSe, the kernels are coated with CdS. Within this study, similar phenomena are found with coated oxide nanoparticles having sizes of ca. 6 nm exhibiting a very narrow particle size distribution. The coating consists of a second ceramic phase or a polymer one, each one influencing fluorescence differently. Obviously, the type of coating is a tool to modify fluorescence. This behavior is demonstrated on kernels made of Al2O3, ZrO2, HfO2, ZnO etc. PMMA, PTFE, or Al2O3were used as coating material. In most cases, the fluorescence spectra showed broad bands. In some cases, such as ZnO, additionally, a sharp emission line in the UV appears. It is interesting to note that coatings made of fluorine containing polymer materials did not lead to fluorescence intensities comparable with PMMA coatings. The observed spectra are equivalent whether the powder is in aqueous suspensions or dry on a quartz glass carrier. The experimental results in this study indicate that the combination of non-fluorescent oxide core with a non-fluorescent polymer coating may lead to a nanocomposite with strong fluorescence. This is a phenomenon not described in literature until now.

scholarly journals Development of Technological Solutions for Sewer Rehabilitation Using Clinker Brick

2021 ◽  
Vol 20 (6) ◽  
pp. 499-505
Author(s):  
D. F. Goncharenko ◽  
A. I. Aleinikova ◽  
S. V. Yesakova ◽  
R. I. Hudilin
Keyword(s):  
Polymer Materials ◽  
The Finite Element Method ◽  
Corrosion Resistant ◽  
Sewer Rehabilitation ◽  
Lining Structure ◽  
Clinker Brick ◽  
Cost Of Materials ◽  
The Cost ◽  
The City ◽  
Selection Of

The aim of the work is to develop a technology for the restoration of damaged sections of sewer collectors using clinker bricks. A significant part of such collectors in the Ukraine has completely exhausted their depreciation resource. For their construction, concrete and reinforced concrete were used, which are subject to destruction as a result of the influence of many factors and, above all, microbiological corrosion. Therefore, the selection of the optimal repair technology using corrosion-resistant clinker brick is relevant. The paper considers the problems of repair and reconstruction of worn-out collectors. Technical and technological solutions of an open method for their recovery using pneumatic formwork and corrosionresistant clinker brick are presented. The design of the collector lining structure has been carried out using the finite element method. To justify the feasibility of using the proposed technology, two options for restoring a worn-out collector have been considered: the “pipe-in-pipe” method and method developed by the authors using clinker bricks. The second option in terms of the cost of materials is almost four times more economical and more expedient than the first one (where polymer materials are used). The advantage of restoring circular sewer collectors by means of laying clinker bricks lies in the durability and resistance of this material (taking into account the anticorrosive composition of concrete) to the aggressive effects of the sewer environment. It should be noted that the application of the developed restoration technology is the most appropriate in conditions of sparse building or outside the city due to the significant volume of earthworks.

INVESTIGATION OF SLIDING PROPERTIES OF SELECTED PLASTICS AND GREASES APPLIED FOR ELEMENTS OF WINTER SPORT EQUIPMENT

Tribologia ◽  
2018 ◽  
Vol 282 (6) ◽  
pp. 11-15
Author(s):  
Anna BROŃCZYK ◽  
Piotr KOWALEWSKI ◽  
Damian PIEKARZ
Keyword(s):  
Friction Coefficient ◽  
Frictional Resistance ◽  
Polymer Materials ◽  
Climatic Chamber ◽  
Winter Sports ◽  
Winter Sport ◽  
Sport Equipment ◽  
Pin On Disc ◽  
Snow Conditions ◽  
Selection Of

The article presents the results of friction coefficient measurements of selected polymer materials applied for elements of winter sports equipmentsliding against ice. After testing, one of thematerials, polyethylene, which is the most commonly used material for ski slides, was selected and tested again, this time, in the presence of various types of ski lubricants. The research was carried out on a pin-on-disc tester placed in a climatic chamber. Obtained results revealed that the selection of the lubricant is a matter of great importance to the reductionof the frictional resistance and should be strictly conditioned by the ambient temperature and associated prevailing snow conditions.

scholarly journals Bolted fibre-reinforced polymer flange joints for pipelines: A review of current practice and future challenges

2018 ◽  
Vol 233 (8) ◽  
pp. 1698-1717
Author(s):  
Muhsin Aljuboury ◽  
Md Jahir Rizvi ◽  
Stephen Grove ◽  
Richard Cullen
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Design Guidelines ◽  
Polymer Materials ◽  
Harsh Environments ◽  
Reinforced Polymer ◽  
Future Challenges ◽  
Fibre Reinforced Polymer ◽  
Bolted Flange ◽  
Selection Of

Metallic bolted flanges and pipes have both been increasingly replaced by fibre-reinforced polymer materials in many applications which deal with extreme harsh environments such as oil, chemical, marine, etc. This is not only due to the fibre-reinforced polymer material’s resistance to the chemical reaction but also due to their inherent mechanical properties of high strength to weight ratio. However, very little research has been published regarding bolted flange joints made of fibre-reinforced polymer materials. Also, the availability of standards and relevant design codes are very limited for bolted fibre-reinforced polymer flange joints. Hence, the design guidelines, dimensional considerations and selection of fabrication methods for the bolted fibre-reinforced polymer flange joints have yet to be optimized fully. For instance, the ASME Boiler and Pressure Vessel Code, section X and ASME PCC-1-2013 appendix O or other similar standards do not include specific rules for the design of the bolted fibre-reinforced polymer flange joints. As a result, it is difficult to understand the consequences on the reliability of fibre-reinforced polymer flanges made with parametric variations and dimensional alterations. This has led the authors to carry out research to maximise the performance of the bolted fibre-reinforced polymer flange joints through a series of experimenters and numerical simulations. The present article will focus on the available techniques to manufacture the bolted fibre-reinforced polymer flanges along with the associated issues and possible challenges compared to metallic flanges.

Cognitive gadgets and cognitive priors

2019 ◽  
Vol 42 ◽  
Author(s):  
Gian Domenico Iannetti ◽  
Giorgio Vallortigara
Keyword(s):  
Cognitive Neuroscience ◽  
Selection Of

Abstract Some of the foundations of Heyes’ radical reasoning seem to be based on a fractional selection of available evidence. Using an ethological perspective, we argue against Heyes’ rapid dismissal of innate cognitive instincts. Heyes’ use of fMRI studies of literacy to claim that culture assembles pieces of mental technology seems an example of incorrect reverse inferences and overlap theories pervasive in cognitive neuroscience.

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