High Performance, Light weight Thermoplastic/Rare Earth Alloy Magnets

1999 ◽  
Vol 577 ◽  
Author(s):  
Jun Xiao ◽  
Joshua U. Otaigbe
Keyword(s):  
Rare Earth ◽  
High Performance ◽  
Mechanical Performance ◽  
High Strength ◽  
Polyphenylene Sulfide ◽  
Exploratory Research ◽  
Rare Earth Alloy ◽  
Crystal Polymer ◽  
High Performance Polymer

ABSTRACTWe report progress on our exploratory research on surface modification of magnetic NdFeB fillers, characterization of suitable magnetic rare earth alloy powders and high-performance polymer matrices, processability, and properties of novel thermoplastic/NdFeB magnets. The results suggest that blending liquid crystal polymer (LCP) with a high-thermoplastic polymer such as polyphenylene sulfide (PPS) provides the required balance of properties. These properties include superior magneto-mechanical performance, minimal melt viscosity at optimal NdFeB volume loading, enhanced thermal stability, high stiffness, high strength, improved dimensional stability, and excellent chemical resistance; making the thermoplastics magnets suitable for use in high temperature and aggressive environments where commercial polymer-bonded magnets are not useable.

Fiber element modeling of circular double-skin concrete-filled stainless-carbon steel tubular columns under axial load and bending

2022 ◽  
pp. 136943322110651
Author(s):  
Mizan Ahmed ◽  
Qing Quan Liang ◽  
Ahmed Hamoda
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
High Performance ◽  
Mechanical Performance ◽  
Axial Strain ◽  
High Strength ◽  
Offshore Structures ◽  
Numerical Results ◽  
Beam Columns ◽  
Double Skin

Circular concrete-filled double-skin steel tubular (CFDST) columns with external stainless-steel are high-performance composite columns that have potential applications in civil construction including the construction of offshore structures, bridge piers, and transmission towers. Reflecting the limited research performed on investigating their mechanical performance, this study develops a computationally efficient fiber model to simulate the responses of short and slender beam-columns accounting for the influences of material and geometric nonlinearities. Accurate material laws of stainless steel, carbon steel, and confined concrete are implemented in the mathematical modeling scheme developed. A new solution algorithm based on the Regula-Falsi method is developed to maintain the equilibrium condition. The independent test results of short and slender CFDST beam-column are utilized to validate the accuracy of the theoretical solutions. The influences of various column parameters are studied on the load-axial strain [Formula: see text] curves, load-lateral deflection [Formula: see text] curves, column strength curves, and interaction curves of CFDST columns. Design formulas are suggested for designing short and beam-columns and validated against the numerical results. The computational model is found to be capable of simulating the responses of CFDST short and slender columns reasonably well. Parametric studies show that the consideration of the concrete confinement is important for the accuracy of the prediction of their mechanical responses. Furthermore, high-strength concrete can be utilized to enhance their load-carrying capacity particularly for short and intermediate slender beam-columns. The strengths of CFDST columns computed by the suggested design model are in good agreement with the test and numerical results.

SUSTAINABLE ULTRA-HIGH-PERFORMANCE GLASS CONCRETE FOR INFRASTRUCTURES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Arezki Tagnit-Hamou ◽  
Nancy A. Soliman
Keyword(s):  
High Performance ◽  
Glass Powder ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Low Cost ◽  
Research Work ◽  
High Strength ◽  
Quartz Powder ◽  
Ultra High Performance Concrete ◽  
Powder Particles

This paper presents research work on the development of a green type of ultra-high-performance concrete using ground glass powders with different degrees of fineness (UHPGC). This article presents the development of an innovative, low-cost, and sustainable UHPGC through the use of glass powder to replace cement, and quartz powder particles. An UHPGC with a compressive strength (fc) of up to 220 MPa was prepared and its fresh, and mechanical properties were investigated. The test results indicate that the fresh UHPGC properties were improved when the cement and quartz powder were replaced with non-absorptive glass powder particles. The strength improvement can be attributed to the glass powder’s pozzolanicity and to its mechanical performance (very high strength and elastic modulus of glass). A case study of using this UHPGC is presented through the design and construction of a footbridge. Erection of footbridge at University of Sherbrooke Campus using UHPGC is also presented as a full-scale application.

Materials and Processing Designs for High-Performance Magnesium Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 453-456
Author(s):  
Katsuyoshi Kondoh ◽  
Ritsuko Tsuzuki ◽  
Wenbo Du ◽  
Shigeharu Kamado
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Rare Earth ◽  
Solid State ◽  
Magnesium Alloys ◽  
High Performance ◽  
Plastic Working ◽  
Coarse Powder ◽  
Rare Earth Alloy ◽  
High Ultimate Tensile Strength

Materials and processing designs for advanced magnesium alloys with fine microstructures and superior properties were established by the combination of the repeated plastic working and the Mg2Si synthesis in solid-state. The grain size was less than 1 μm via RPW process due to its severe plastic working on raw powder. The hot extruded magnesium alloys produced in industries showed high ultimate tensile strength, e.g. 420~450MPa, when employing Mg-Zn-Al-Ca-RE (Rare Earth) alloy coarse powder, having 0.5~2 mm diameter, as input materials.

Nonvolatile resistive memories utilizing functional PES-based supramolecular film

2017 ◽  
Vol 30 (9) ◽  
pp. 1056-1063 ◽  
Author(s):  
Hejing Sun ◽  
Haibo Zhang ◽  
Zheng Chen ◽  
Jinhui Pang ◽  
Cong Gao ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
High Performance ◽  
Memory Device ◽  
Memory Devices ◽  
Resistive Switching Memory ◽  
Threshold Voltages ◽  
High Performance Polymer ◽  
Fabrication And Characterization ◽  
First Time

This study reports the fabrication and characterization of polymer resistive switching memory devices fabricated from poly(ether sulfone)s (PESs), containing carboxylic functional groups for hydrogen bonding with disperse red 1. PES-based supramolecular memory devices exhibited write-once read-many-times-type memory effects, with low switching threshold voltages below −5.0 V and high ON/OFF current ratios of 105. It is the first time that the concept of azobenzene supramolecular PES based on hydrogen bonding for electrical memory device application was investigated. A possible switching mechanism based on the charge transfer interaction was proposed through molecular simulation, optical absorption, and cyclic voltammetry. These results render the PES-based supramolecular memory devices as promising components for high-performance polymer memory devices.

Synthesis and characterization of a thiazolo[5,4-d]thiazole-based copolymer for high performance polymer solar cells

2011 ◽  
Vol 47 (6) ◽  
pp. 1791-1793 ◽  
Author(s):  
Sang Kyu Lee ◽  
Jung Min Cho ◽  
Youngran Goo ◽  
Won Suk Shin ◽  
Jong-Cheol Lee ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Polymer Solar Cells ◽  
Synthesis And Characterization ◽  
High Performance Polymer

Microstructural Features of Recycled Aggregate Concrete: From Non-Structural to High-Performance Concrete

2019 ◽  
Vol 25 (3) ◽  
pp. 601-616 ◽  
Author(s):  
Diogo Pedro ◽  
Mafalda Guedes ◽  
Jorge de Brito ◽  
Luís Evangelista
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Sequential Approach

AbstractThe use of concrete-recycled aggregates to produce high-performance concrete is limited by insufficient correlation between resulting microstructure and its influence on mechanical performance reproducibility. This work addresses this issue in a sequential approach: concrete microstructure was systematically analyzed and characterized by scanning electron microscopy and results were correlated with concrete compressive strength and water absorption ability. The influence of replacing natural aggregates (NA) with recycled concrete aggregates (RCA), with different source concrete strength levels, of silica fume (SF) addition and of mixing procedure was tested. The results show that the developed microstructure depends on the concrete composition and is conditioned by the distinct nature of NA, recycled aggregates from high-strength source concrete, and recycled aggregates from low-strength source concrete. SF was only effective at concrete densification when a two-stage mixing approach was used. The highest achieved strength in concrete with 100% incorporation of RCA was 97.3 MPa, comparable to that of conventional high-strength concrete with NA. This shows that incorporation of significant amounts of RCA replacing NA in concrete is not only a realistic approach to current environmental goals, but also a viable route for the production of high-performance concrete.

Experiment Study on Mechanical Performance of Shale Lightweight Aggregate Concrete

2012 ◽  
Vol 530 ◽  
pp. 80-84 ◽  
Author(s):  
Lin Li ◽  
Qing Wang ◽  
Yu Wang ◽  
Zhao Yang Ding
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Mechanical Performance ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Mineral Admixtures ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Volume Stability ◽  
Binder Ratio

High performance lightweight aggregate concrete is a kind of lightweight environment-protected building material with high strength, good workability, volume stability and durability, which is widely used in large scale engineering and some important engineering. In this paper water-binder ratio, fly ash content, pre-wetting time, sand ratio were tested to explore the comprehensive strength of lightweight aggregate concrete(LWAC). SEM was used to observe the microstructure characteristics of the specimens. The results showed that LWAC produced in the experiment present good performance, whose apparent density was 1760 Kg/m3～1930Kg/m3, 28d compressive strength was 55MPa～60MPa. Reasonable amounts of sand ratio(38%) and mineral admixtures(10%) were exited and the self-strength of lightweight aggregate played an important role in the preparation of LWAC. In the meanwhile, lightweight aggregates which were pre-wetted effectively increased the later strength.

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