scholarly journals 2D exhaust nozzle with multiple composite layers for IR signature suppression

2020 ◽  
Vol 19 ◽  
pp. 103395
Author(s):  
Sun Je Kim ◽  
Yeong Ryeon Kim ◽  
Yongha Kim ◽  
Myung Ho Kim ◽  
MyungSup Lee
Keyword(s):  
Composite Layers ◽  
Ir Signature

scholarly journals Low-Temperature Mineralisation of Titania-Siloxane Composite Layers

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Tomáš Svoboda ◽  
Michal Veselý ◽  
Radim Bartoš ◽  
Tomáš Homola ◽  
Petr Dzik
Keyword(s):  
Low Temperature ◽  
Great Influence ◽  
Gel Permeation Chromatography ◽  
Photocatalytic Decomposition ◽  
Acid Orange 7 ◽  
Composite Layers ◽  
Nonthermal Treatment ◽  
Plasma Methods ◽  
Voltammetric Measurements ◽  
Thermally Treated

This paper deals with low-temperature mineralisation of coatings made with titania-siloxane compositions (TSC). Methyltriethoxysilane has been adopted as the precursor for the siloxane, and during its synthesis, an oligomeric siloxane condensate with methyl moieties acting as TiO2 binder has been produced. These methyl moieties, contained in TSC, provide solubility and prevent gelling, but reduce the hydrophilicity of the system, reduce the transfer of electrons and holes generated in the TiO2. In order to avoid these unfavourable effects, TSC mineralisation can be achieved by nonthermal treatment, for example, by using UV-radiation or plasma treatment. Characterisation of the siloxane was performed by gel permeation chromatography (GPC), which showed the size of the siloxane chain. Thermogravimetric analysis revealed a temperature at which the siloxane mineralises to SiO2. Printed layers of two types of TSC with different siloxane contents were studied by a scanning electron microscope (SEM), where a difference in the porosity of the samples was observed. TSC on fluorine-doped tin oxide (FTO) coated glass and microscopic glass were treated with non-thermal UV and plasma methods. TSC on FTO glass were tested by voltammetric measurements, which showed that the non-thermally treated layers have better properties and the amount of siloxane in the TSC has a great influence on their efficiency. Samples on microscopic glass were subjected to a photocatalytic decomposition test of the model pollutant Acid orange 7 (AO7). Non-thermally treated samples show higher photocatalytic activity than the raw sample.

The effect of nanoparticle additive on surface milling in glass fiber reinforced composite structures

2021 ◽  
pp. 096739112110141
Author(s):  
Ferhat Ceritbinmez ◽  
Ahmet Yapici ◽  
Erdoğan Kanca
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Composite Structures ◽  
Fiber Composite ◽  
Cutting Speed ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Composite Layers

In this study, the effect of adding nanosize additive to glass fiber reinforced composite plates on mechanical properties and surface milling was investigated. In the light of the investigations, with the addition of MWCNTs additive in the composite production, the strength of the material has been changed and the more durable composite materials have been obtained. Slots were opened with different cutting speed and feed rate parameters to the composite layers. Surface roughness of the composite layers and slot size were examined and also abrasions of cutting tools used in cutting process were determined. It was observed that the addition of nanoparticles to the laminated glass fiber composite materials played an effective role in the strength of the material and caused cutting tool wear.

scholarly journals Bianisotropic metasurfaces: physics and applications

Nanophotonics ◽  
2018 ◽  
Vol 7 (6) ◽  
pp. 1069-1094 ◽  
Author(s):  
Viktar S. Asadchy ◽  
Ana Díaz-Rubio ◽  
Sergei A. Tretyakov
Keyword(s):  
State Of The Art ◽  
Surface Current ◽  
Magnetic Surface ◽  
Magnetic Polarization ◽  
Research Directions ◽  
Magnetic Current ◽  
Asymmetric Reflection ◽  
Composite Layers ◽  
Electric And Magnetic Fields

AbstractMetasurfaces as optically thin composite layers can be modeled as electric and magnetic surface current sheets flowing in the layer volume in the metasurface plane. In the most general linear metasurface, the electric surface current can be induced by both incident electric and magnetic fields. Likewise, magnetic polarization and magnetic current can be induced also by external electric field. Metasurfaces which exhibit magnetoelectric coupling are called bianisotropic metasurfaces. In this review, we explain the role of bianisotropic properties in realizing various metasurface devices and overview the state-of-the-art of research in this field. Interestingly, engineered bianisotropic response is seen to be required for realization of many key field transformations, such as anomalous refraction, asymmetric reflection, polarization transformation, isolation, and more. Moreover, we summarize previously reported findings on uniform and gradient bianisotropic metasurfaces and envision novel and prospective research directions in this field.

Numerical analysis of the temperature profile during the laser-assisted automated fiber placement of CFRP tapes with thermoplastic matrix

2017 ◽  
Vol 31 (12) ◽  
pp. 1563-1586 ◽  
Author(s):  
Andreas Kollmannsberger ◽  
Roland Lichtinger ◽  
Franz Hohenester ◽  
Christoph Ebel ◽  
Klaus Drechsler
Keyword(s):  
Carbon Fiber ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Fiber Placement ◽  
Composite Layers ◽  
Automated Fiber Placement ◽  
Geometric Boundary ◽  
Laser Heat Source ◽  
Placement Machine

In this study, a thermodynamic model of a laser-assisted automated thermoplastic fiber placement process is developed and validated. The main focus is on modeling the heat transfer into the composite with a laser heat source, the thermal properties of the tape, and the resulting heat distribution in the part, the mold, and the compaction roller. A new integrated analytical method is presented to calculate the energy input of the laser based on the geometric boundary conditions, including first-order reflection and laser shadow. The carbon fiber/polyethersulphone tape is modeled by combining literature properties of carbon fiber and matrix as well as based on experimental data of the tape itself. Also a thermal contact resistance between the tape layers is modeled based on a literature model and own experimental measurements. The created model is discretized and implemented in a 2-D finite difference code. With the help of this simulation, the temperature distribution is calculated during layup. The influence of a possible thermal contact resistance between the composite layers is investigated. Furthermore, an experiment with a thermoplastic fiber placement machine from Advanced Fibre Placement Technology GmbH (AFPT) was conducted in order to evaluate the simulation. The simulation and the experiment show a good agreement and prove that thermal contact resistance between the layers is negligible for the investigation process.

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