scholarly journals Process-Induced Distortions Characterization of MBWK Fabric Reinforced Composite Helmet Shell

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2983
Author(s):  
He Xiang ◽  
Yaming Jiang ◽  
Yexiong Qi ◽  
Jialu Li
Keyword(s):  
Thin Shell ◽  
High Performance ◽  
Laser Scanning ◽  
Textile Composites ◽  
Reinforced Composite ◽  
Measurement Results ◽  
Calculation Results ◽  
High Performance Composite ◽  
Working Procedure

In order to characterize the process-induced distortions of 3D thin shell composites with complex shape, the multilayered biaxial weft knitted (MBWK) fabric reinforced high-performance composite helmet was selected as the research object, and the 3D laser scanning machine was used to scan the helmet surface, then the 3D scanning data was compared with the CAD model to evaluate the deformation. The results and discussion indicated that the conventional method was workable, but the speed of convergence was slow and the calculation results were easy to drop into local optimization. According to detailed analysis, a measurement method focusing on the principle of “Feature Distance” was developed. The measurement results shown that this method can not only give accurate results, but also reduce working procedure and greatly save the computing resources, which is proved to be a feasible approach for the deformation measurement foundation of 3D thin shell textile composites.

Synthesis and Characterization of Fluorinated Alkyl Substituted Disiloxane

2014 ◽  
Vol 529 ◽  
pp. 13-15
Author(s):  
Qing Chuan Xi ◽  
Ke Cao ◽  
Ya Wen Huang ◽  
Guan Jun Chang ◽  
Jun Xiao Yang
Keyword(s):  
High Performance ◽  
Chemical Structure ◽  
Rust Resistance ◽  
Condensation Reaction ◽  
Synthesis And Characterization ◽  
Silicon Oil ◽  
Temperature Performance ◽  
Diffusion Pump ◽  
Measurement Results

Alkyl substituted disiloxanes demonstrated promising applications as high performance hydraulic oil, diffusion pump oil, etc. In this study, fluorinated alkyl substituted disiloxane was synthesized via Grignard reaction followed by condensation reaction. Its chemical structure was verified by FTIR and NMR. Measurement results showed that this silicon oil exhibited good high temperature performance, oxidation resistance and rust resistance.

Design and characterization of an active recovering mechanism for high-performance RF MEMS redundancy switches

2011 ◽  
Vol 3 (5) ◽  
pp. 539-546 ◽  
Author(s):  
Francesco Solazzi ◽  
Augusto Tazzoli ◽  
Paola Farinelli ◽  
Alessandro Faes ◽  
Viviana Mulloni ◽  
...  
Keyword(s):  
High Performance ◽  
Rf Mems ◽  
Time To Failure ◽  
Micro Electro Mechanical Systems ◽  
Mems Switch ◽  
Rf Measurement ◽  
Switch Time ◽  
Measurement Results ◽  
Better Than

This paper presents the design and characterization of an active push/pull toggle RF micro-electro-mechanical systems (MEMS) switch for satellite redundancy networks. The actively controlled pull-up mechanism allows for extended restoring capabilities of the switch in case of ON-state stiction. As a proof of concept an active push/pull MEMS capacitive switch was modeled, designed, and manufactured in shunt configuration on a 50 Ω coplanar transmission line. RF measurement results show a return loss better than 15 dB in the 0.1–40 GHz range and an insertion loss better than 0.5 dB over the same range. The restoring capability of the switch was experimentally proved up to 9 h, and a predictive model was proposed for the estimation of the switch time to failure.

scholarly journals Synthesis and characterization of some composites with bioactive properties on the basis of vinyl ester resins

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Dan Rosu ◽  
Constantin N. Cascaval ◽  
Liliana Rosu
Keyword(s):  
Vinyl Ester ◽  
High Performance ◽  
Point Of View ◽  
Synthesis And Characterization ◽  
Vinyl Ester Resin ◽  
Volume Contraction ◽  
Bioactive Properties ◽  
High Performance Composite ◽  
Vinyl Ester Resins

AbstractVinyl ester resins are unsaturated polyesters, widely used as matrix for high performance composite materials. The paper presents the synthesis and characterization of some vinyl ester resin/hydroxyapatite bioactive compositions using an unsaturated copolyester based on turpentine oil as reactive diluent. The vinyl ester oligomer /unsaturated copolyester/hydroxyapatite structural complex was characterized from the morphological point of view, water absorbtion, density measurements and volume contraction. The water uptake is dependent on the concentration in vinyl ester resin. The increase of the vinyl ester resin content in the bioactive composite leads to the increase of the density, respectively to a significant decrease of the volume contraction

CO2 Permeability Characterization of High Performance Composite Coating

2014 ◽  
Vol 529 ◽  
pp. 117-121 ◽  
Author(s):  
An Qing Fu ◽  
Yang Zhou ◽  
Ming Jie Zhu ◽  
Yao Rong Feng ◽  
Xun Ji Li ◽  
...  
Keyword(s):  
Composite Coating ◽  
High Performance ◽  
Organic Coatings ◽  
Measurement Methodology ◽  
High Performance Composite

In this work, the permeability of high performance composite coating (HPCC) and its containing layers fusion bonded epoxy (FBE) and middle density polyethylene (MDPE) to dissolved CO2 was investigated. The obtained results showed that the permeability to dissolved CO2 of HPCC, FBE, and MDPE are in order of HPCC<FBE<MDPE, the corresponding values of three coatings are 1.27 × 10-11 mol/atm⋅m⋅s, 1.54 × 10-11, and 3.51×10-10 mol/atm⋅m⋅s, respectively. The measurement methodology of dissolved CO2 permeability on organic coatings is feasible based on the present work.

scholarly journals Formulation of a Model Resin System for Benchmarking Processing-Property Relationships in High-Performance Photo 3D Printing Applications

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4109
Author(s):  
Jianwei Tu ◽  
Kamran Makarian ◽  
Nicolas J. Alvarez ◽  
Giuseppe R. Palmese
Keyword(s):  
3D Printing ◽  
High Performance ◽  
Mechanical Analysis ◽  
Resin System ◽  
Processing Property ◽  
High Mechanical Strength ◽  
Reinforced Composite ◽  
And Performance ◽  
Tan Δ

A well-defined resin system is needed to serve as a benchmark for 3D printing of high-performance composites. This work describes the design and characterization of such a system that takes into account processability and performance considerations. The Grunberg–Nissan model for resin viscosity and the Fox equation for polymer Tg were used to determine proper monomer ratios. The target viscosity of the resin was below 500 cP, and the target final Tg of the cured polymer was 150 °C based on tan-δ peak from dynamic mechanical analysis. A tri-component model resin system, termed DA-2 resin, was determined and fully characterized. The printed polymer exhibited good thermal properties and high mechanical strength after post-cure, but has a comparatively low fracture toughness. The model resin will be used in additive manufacturing of fiber reinforced composite materials as well as for understanding the fundamental processing–property relationships in light-based 3D printing.

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

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