scholarly journals Review of materials used for ballast reinforcement

2021 ◽  
Author(s):  
Majd Ahmad
Keyword(s):  
Mechanical Properties ◽  
Maintenance Cost ◽  
Binding Agents ◽  
Overall Evaluation ◽  
Materials Used ◽  
Reasonable Price

This mini review summarizes the most recent research in ballast reinforcement. Several materials are being used for the purpose of improving the ballast layer in railways, including geosynthetics, rubber sheets and binding agents. Such methods of reinforcement have proven to be beneficial for increasing the strength, stiffness, and resilience of the ballast layer in addition to reducing settlement, breakage, degradation, and maintenance cost and frequency. Latest studies try to find the best types, placement, and combination of geosynthetics to achieve the highest strength and resistance, in addition to obtaining the optimum percentage of binding agents and methods of applying them in order to discover the most effective binder that achieves the most improvement to the mechanical properties of the layer for a reasonable price. An overview of the recent tests conducted to study the reinforced ballast layer and their results is presented in this paper, as well as an overall evaluation of the implementation of these reinforcement methods in railways.

scholarly journals A review of wear resistance materials used in power-screw mechanism for aerospace applications

2021 ◽  
Vol 1206 (1) ◽  
pp. 012020
Author(s):  
KS Ujjwal ◽  
N Sharath Chandra
Keyword(s):  
Mechanical Properties ◽  
Prime Factor ◽  
Maintenance Cost ◽  
Actuation Mechanism ◽  
Aerospace Applications ◽  
Aluminium Bronze ◽  
Material Choice ◽  
Screw Mechanism ◽  
Materials Used ◽  
Made In

Abstract In today’s industrial requirement, good wear resistant materials with the same or better mechanical properties are the need of the hour. In the present paper, an actuator that is used to lift the load is under study. It uses a linear actuation mechanism involving a screw-like motion to lift the loads. It employs a stainless steel of high quality. Since there are various types of wearing involved in the system, choice of the materials becomes the prime factor for determining the maintenance cost and the cycle life of the actuator. There are many research advances made in this field which provides us with the best type of material for its particular type of job. The present paper discusses the materials that could be substituted in place of the existing material choice i.e., in place of AMS5659 and aluminium-bronze. The two materials stated above are known for its superior wear handling and excellent mechanical properties.

Emerging Techniques for the Characterization of Nano-Mechanical Properties of Integrated Circuit Components

2008 ◽  
Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Manufacturing Process ◽  
Solder Bumps ◽  
Initial Work ◽  
Circuit Components ◽  
Materials Used

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.

scholarly journals Analysis of the Impact on the Mechanical Properties of Modification of Oligohydroxyethers in Organic Solvent Solution with Rubbers

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 519
Author(s):  
Vitalii Bezgin ◽  
Agata Dudek ◽  
Adam Gnatowski
Keyword(s):  
Mechanical Properties ◽  
Scientific Paper ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Wide Range ◽  
Strength Tests ◽  
Materials Used ◽  
Styrene Butadiene ◽  
The Impact

This paper proposes and presents the chemical modification of linear hydroxyethers (LHE) with different molecular weights (380, 640, and 1830 g/mol) with the addition of three types of rubbers (polysulfide rubber (PSR), polychloroprene rubber (PCR), and styrene-butadiene rubber (SBR)). The main purpose of choosing this type of modification and the materials used was the possibility to use it in industrial settings. The modification process was conducted for a very wide range of modifier additions (rubber) per 100 g LHE. The materials obtained in the study were subjected to strength tests in order to determine the effect of the modification on functional properties. Mechanical properties of the modified materials were improved after the application of the modifier (rubber) to polyhydroxyether (up to certain modifier content). The most favorable changes in the tested materials were registered in the modification of LHE-1830 with PSR. In the case of LHE-380 and LHE-640 modified in cyclohexanol (CH) and chloroform (CF) solutions, an increase in the values of the tested properties was also obtained, but to a lesser extent than for LHE-1830. The largest changes were registered for LHE-1830 with PSR in CH solution: from 12.1 to 15.3 MPa for compressive strength tests, from 0.8 to 1.5 MPa for tensile testing, from 0.8 to 14.7 MPa for shear strength, and from 1% to 6.5% for the maximum elongation. The analysis of the available literature showed that the modification proposed by the authors has not yet been presented in any previous scientific paper.

scholarly journals Injectable non-leaching tissue-mimetic bottlebrush elastomers as an advanced platform for reconstructive surgery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew N. Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

AbstractCurrent materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

Characterization of NiCrMo Dental Restoration Alloy

2021 ◽  
Vol 875 ◽  
pp. 373-378
Author(s):  
Ali Haider ◽  
Omar Farooq Azam ◽  
Muhammad Talha ◽  
Saleem Akhtar
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Dental Materials ◽  
Dental Restoration ◽  
Restorative Material ◽  
Nicr Alloy ◽  
In Vitro Biocompatibility ◽  
Dental Prostheses ◽  
Materials Used

Restorative material is a class of dental materials used for direct filling and fabrication of indirect restoration. NiCr alloy is a restorative material frequently used for dental prostheses due to its properties and economic reasons. In present work beryllium free NiCrMo alloy was developed and studied for dental restoration application. The alloy have unique characteristics of resistance to oxidation and biocompatibility; the requisites for dental prostheses. NiCrMo alloy is found to possess mechanical strength and fabrication properties suitable for dental repairs. In this study the developed alloy was tested for its mechanical properties, biocompatibility and corrosion resistance. An in-vitro biocompatibility study was carried out. No signs of toxicity and no signs of cell growth inhibition, in presence of NiCrMo alloy specimen, were observed. Mechanical properties and corrosion resistance are found in the range that is suitable for dental prostheses and easy fabrication.

Performance and Mechanical Properties of Various Padding Materials Used in Cadaveric Side Impact Sled Tests

1992 ◽  
Author(s):  
John M. Cavanaugh ◽  
Yonghua J. Zhu ◽  
Yue Huang ◽  
Albert I. King
Keyword(s):  
Mechanical Properties ◽  
Side Impact ◽  
Materials Used

scholarly journals Injectable Non-leaching Tissue-mimetic Bottlebrush Elastomers: A New Platform for Advancing Reconstructive Surgery

2020 ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

Abstract Current materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

Location Depending Textures of the Human Dental Enamel

2010 ◽  
Vol 160 ◽  
pp. 281-286 ◽  
Author(s):  
Lars Raue ◽  
Helmut Klein
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Dental Enamel ◽  
Polymeric Materials ◽  
Incisor Tooth ◽  
Worst Case ◽  
Dental Fillings ◽  
Anisotropic Mechanical Properties ◽  
Different Types ◽  
Materials Used

Dental enamel is the most highly mineralised and hardest biological tissue in human body [1]. Dental enamel is made of hydroxylapatite (HAP) - Ca5(PO4)3(OH), which is hexagonal (6/m). The lattice parameters are a = b = 0.9418 nm und c = 0.6875 nm [1]. Although HAP is a very hard mineral, it can be dissolved easily in a process which is known as enamel demineralization by lactic acid produced by bacteria. Also the direct consumption of acid (e.g. citric, lactic or phosphoric acid in soft drinks) can harm the dental enamel in a similar way. These processes can damage the dental enamel. It will be dissolved completely and a cavity occurs. The cavity must then be cleaned and filled. It exists a lot of dental fillings, like gold, amalgam, ceramics or polymeric materials. After filling other dangers can occur: The mechanical properties of the materials used to fill cavities can differ strongly from the ones of the dental enamel itself. In the worst case, the filling of a tooth can damage the enamel of the opposite tooth by chewing if the interaction of enamel and filling is not equivalent, so that the harder fillings can abrade the softer enamel of the healthy tooth at the opposite side. This could be avoided if the anisotropic mechanical properties of dental enamel would be known in detail, hence then another filling could be searched or fabricated as an equivalent opponent for the dental enamel with equal properties. To find such a material, one has to characterise the properties of dental enamel first in detail for the different types of teeth (incisor, canine, premolar and molar). This is here exemplary done for a human incisor tooth by texture analysis with the program MAUD from 2D synchrotron transmission images [2,3,4].

A NOVEL, SCALABLE PRODUCTION OF MULTIFUNCTIONAL NANOCOMPOSITE POLYMER FILAMENTS FOR ADDITIVE MANUFACTURING

2021 ◽  
Author(s):  
MIA CARROLA ◽  
AMIR ASADI
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Additive Manufacturing ◽  
Aqueous Suspension ◽  
Manufacturing Method ◽  
Nanocomposite Polymer ◽  
Water As Solvent ◽  
Materials Used ◽  
Scalable Production

Though a revolutionary process, additive manufacturing (AM) has left more to be desired from printed parts, specifically, improved interlayer strength and minimal defects such as porosity. To overcome these common issues, nanocomposites have become one of the most popular materials used in AM, with various nanoparticles used to achieve a variety of characteristics. The use of these technologies together allows for both to synergistically enhance the final printed parts by improving the process and products simultaneously. Here, we introduce a novel, scalable technique to coat ABS pellets with cellulose nanocrystal (CNC) bonded carbon nanotubes (CNT), to improve the adhesion between layers as well as the mechanical properties of printed parts. An aqueous suspension of CNT-CNC is used to coat ABS pellets before they are dried and extruded into filament for printing. The filament produced using this manufacturing method showed an increase in tensile and interlayer strength as well as improved thermal conductivity. This process uses water as solvent and pristine nanoparticles without the need for any functionalization or surfactants, promoting its scalability. This process has the potential to be used with various polymers and nanoparticles, which allows the materials to be specifically tailored to the end application, (i.e. strength, conductivity, antibacterial, etc.). These nanocomposite filaments have the potential to revolutionize the way that additive manufacturing is utilized in a variety of industries.

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