scholarly journals Importance of Si surface flatness to realize high-performance Si devices utilizing ultrathin films with new material system

2014 ◽  
Vol 11 (14) ◽  
pp. 20142006-20142006 ◽  
Author(s):  
Shun-ichiro Ohmi
Keyword(s):  
Ultrathin Films ◽  
High Performance ◽  
Material System ◽  
Surface Flatness ◽  
New Material

On the Applicability of F2MC Variable Impedance Materials for Prosthetic Devices

2008 ◽  
Author(s):  
Michael Philen
Keyword(s):  
High Performance ◽  
Load Transfer ◽  
Impedance Control ◽  
Joint Control ◽  
Material System ◽  
Matrix Composites ◽  
Prosthetic Devices ◽  
Variable Modulus ◽  
New Material ◽  
Active Impedance

The applicability of variable modulus fluidic flexible matrix composites (F2MC) is investigated for development of prosthetic devices. The F2MC material is an innovative combination of high performance composite tubes containing high bulk modulus fluids. The new material system can potentially achieve several orders of magnitude change in stiffness through valve control. The F2MC material system is investigated in this research through analytical studies for active impedance control for load transfer reduction in a transtibial prosthetic sockets and impedance joint control for an ankle-foot orthoses (AFO). Preliminary analysis results indicate that the variable modulus system can reduce the load transfer between the limb and transtibial socket and can provide impedance tailoring for improving foot-slap in an AFO.

Cross-sectional TEM specimen preparation from magneto-optical disk by ultramicrotomy

1993 ◽  
Vol 51 ◽  
pp. 236-237
Author(s):  
F. Shaapur ◽  
M.J. Kim ◽  
Seh Kwang Lee ◽  
Soon Gwang Kim
Keyword(s):  
System Development ◽  
Thin Foil ◽  
Specimen Preparation ◽  
Material System ◽  
Cross Sectional ◽  
Protective Layers ◽  
New Material ◽  
Diamond Saw ◽  
Original Production ◽  
Thick Medium

TEM characterization and microanalysis of the recording media is crucial and complementary to new material system development as well as quality control applications. Due to the type of material generally used for supporting the medium, i.e., a polymer, conventional macro- and microthinning procedures for thin foil preparation are not applicable. Ultramicrotorny (UM) is a viable option and has been employed in previous similar studies. In this work UM has been used for preparation of XTEM samples from a magneto-optical (MO) recording medium in its original production format.The as-received material system consisted of a 4-layer, 2100 Å thick medium including a 300 Å TbFeCo layer enveloped by silicon nitride protective layers supported on a 1.2 mm thick × 135 mm (5.25 in.) diameter polycarbonate disk. Recording tracks had an approximate pitch of 1.6 μm separated by 800 Å deep peripheral grooves. Using a Buehler Isomet low-speed diamond saw, 1 mm wide and 20 mm long strips were cut out of the disk along the recording tracks.

scholarly journals Environmentally Friendly, High-Performance Fire Retardant Made from Cellulose and Graphite

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2400
Author(s):  
Leandra P. Santos ◽  
Douglas S. da Silva ◽  
Thais H. Morari ◽  
Fernando Galembeck
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Fire Retardant ◽  
Visual Observation ◽  
Flame Resistance ◽  
New Developments ◽  
New Class ◽  
New Material ◽  
Accredited Laboratory ◽  
Materials Used

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.

scholarly journals Fast Preparation of High-Performance Wood Materials Assisted by Ultrasonic and Vacuum Impregnation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Mechanical Tests ◽  
Vacuum Impregnation ◽  
Natural Forests ◽  
Ultrasonic Pretreatment ◽  
Fast Growing ◽  
Before And After ◽  
New Material ◽  
Ft Ir

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.

Attribute Based Selection of Thermoplastic Resin for Vacuum Infusion Process

2011 ◽  
Vol 1 (3) ◽  
pp. 31-52 ◽  
Author(s):  
R. T. Durai Prabhakaran ◽  
Aage Lystrup ◽  
Tom Løgstrup Andersen
Keyword(s):  
Material System ◽  
Mathematical Tool ◽  
Thermoplastic Resin ◽  
Thermoplastic Polymers ◽  
Vacuum Infusion ◽  
Thermosetting Polymers ◽  
Current Scenario ◽  
New Material ◽  
Selection Of ◽  
Vacuum Infusion Process

The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable for different engineering applications, and few of those are available in a not yet polymerised form suitable for resin infusion. The proper selection of a new resin system among these thermoplastic polymers is a concern for manufactures in the current scenario and a special mathematical tool would be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection for vacuum infused of a wind turbine blade—is shown to demonstrate the intricacies involved in the proposed methodology for resin selection.

Rutting Treatment Technology of Asphalt Pavement of Abrupt Slope Section in Heavy Load and High Temperature Zone

2011 ◽  
Vol 287-290 ◽  
pp. 858-861
Author(s):  
Hui Wang ◽  
Zhou Qing Zhao ◽  
Jian Zeng
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Polyester Fibre ◽  
Asphalt Mixture ◽  
Good Control ◽  
Treatment Technology ◽  
Heavy Load ◽  
Test Road ◽  
Overlay Design ◽  
New Material

Aiming at the characteristics of pavement rutting damage of test road under the condition of heavy load and abrupt slope, an overlay design scheme and a new overlay material with high performance was proposed. The new material is PG82 modified asphalt SMA-13 added polyester fibre which can significantly improve the high temperature performance of asphalt mixture under severe environment, and its strength and crack resistance are superior to normal SMA-13. Tracking survey of test road shows that the pavement performances keeps good and rutting is under good control. Therefore those measurements are successful and can be a reference to similar projects.

scholarly journals A Study on the Techniques of Composite Mold Structure for Hovercraft Using New Material System

2008 ◽  
Vol 32 (9) ◽  
pp. 699-703
Author(s):  
Yun-Hae Kim ◽  
Chang-Won Bae ◽  
Keun-Sil Park ◽  
Sung-Youl Bae ◽  
Kyung-Man Moon ◽  
...  
Keyword(s):  
Material System ◽  
New Material

Attribute Based Selection of Thermoplastic Resin for Vacuum Infusion Process

2012 ◽  
pp. 267-288
Author(s):  
R. T. Durai Prabhakaran ◽  
Aage Lystrup ◽  
Tom Løgstrup Andersen
Keyword(s):  
Material System ◽  
Mathematical Tool ◽  
Thermoplastic Resin ◽  
Thermoplastic Polymers ◽  
Vacuum Infusion ◽  
Thermosetting Polymers ◽  
Current Scenario ◽  
New Material ◽  
Selection Of ◽  
Vacuum Infusion Process

The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable for different engineering applications, and few of those are available in a not yet polymerised form suitable for resin infusion. The proper selection of a new resin system among these thermoplastic polymers is a concern for manufactures in the current scenario and a special mathematical tool would be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection for vacuum infused of a wind turbine blade—is shown to demonstrate the intricacies involved in the proposed methodology for resin selection.

A Case Study of Ultra-Leach Resistant Thick Film Conductors for Non-Magnetic Applications

2015 ◽  
Vol 2015 (1) ◽  
pp. 000273-000277
Author(s):  
John J. B. Silvia
Keyword(s):  
Thick Film ◽  
High Performance ◽  
Processing Parameters ◽  
Electronics Manufacturing ◽  
Surface Mount Technology ◽  
New Material ◽  
High Temperature Processing ◽  
Robust Processing ◽  
Very High

Today, designers of SMT electronics are being asked to achieve more while designing around new technical constraints. Many times these constraints force designers to sacrifice commercial advantages of their designs in order to achieve performance goals or vice-versa. This is made worse when industries and regulations impose restrictions on materials such as lead free, high temperature processing, low-PIM or non-magnetic requirements. Often, the choice comes down to either using high performance components that are expensive and sensitive to processing or robust components that either offer reduced performance or are restricted for use due to material content. This is especially true of surface-mount technology components common to electronics manufacturing where solder processing requirements are found. While typical Ag/Pt thick film conductors are a perfect choice for sensitive applications requiring robust processing, they cannot match processing parameters similar to very high leaching resistant materials like nickel barrier. Since nickel barrier is inherently ferro-resonant, some applications cannot be realized without a new material approach. Components manufactured for use in these sensitive, yet demanding applications have now been produced using an Ultra Leach Resistant (ULR) processing of Ag/Pt thick film. The performance of components produced using this ULR material and process have been evaluated for survivability in solder environments to study the resistance to leaching compared to nickel barrier and traditional “leach resistant” materials available today. The results indicate that it is possible to achieve nickel-barrier-like results without ferro-resonant properties using a “ULR” material and process.

scholarly journals Novel 500-GHz Band Waveguide Stepped Septum-Type Circular Polarizer with a New High-Accuracy and Very Small Waveguide Flange

2020 ◽  
Author(s):  
Yutaka Hasegawa ◽  
Hiroyuki Maezawa ◽  
Hideo Ogawa
Keyword(s):  
High Performance ◽  
High Accuracy ◽  
Circular Polarizer ◽  
New Methods ◽  
Position Errors ◽  
Surface Flatness ◽  
Atmospheric Observations ◽  
Dimensional Errors ◽  
Determination Mechanism ◽  
Better Than

Abstract A new waveguide stepped septum-type circular polarizer (SST-CP) was developed to operate in the 500-GHz band for radio astronomical and planetary atmospheric observations. In a previous study, we developed a practical SST-CP for the 230-GHz band. However, several issues prevent this device being easily scaled down to the 500-GHz band, such as manufacturing dimensional errors and waveguide flange position errors. In this study, we developed a new waveguide flange with a high-accuracy position determination mechanism and a very small size of 10 × 10 mm. We also developed a new fabrication technique to obtain very good flatness for the device’s blank materials by high-accuracy polishing using a resin fixture. Using these new methods, the manufactured 500-GHz band SST-CP achieved a cross-polarization talk level of better than – 30 dB at 465–505 GHz, a device surface flatness of within 3 μm, and also the horizontal positioning error of ± 3 μm. These results indicate that the developed 500-GHz band SST-CP has high performance in the high-frequency band, and thus the new manufacturing methods are effective in the 500-GHz band.

Sign in / Sign up

Export Citation Format

Share Document