Durability assessment of polymeric composites for high speed civil transport

2021 ◽  
pp. 387-392
Author(s):  
Thomas S. Gates
Keyword(s):  
High Speed ◽  
Polymeric Composites ◽  
Durability Assessment

Performance and Durability Assessment of Two Emission Control Technologies Installed on a Legacy High-Speed Marine Diesel Engine

2015 ◽  
Author(s):  
Jonathan DeHart ◽  
Robert Russell ◽  
John Storey ◽  
Michael Kass ◽  
Richard DeCorso ◽  
...  
Keyword(s):  
High Speed ◽  
Alternative Fuels ◽  
Emission Control ◽  
Cost Effective ◽  
Operating Conditions ◽  
Marine Engines ◽  
Marine Diesel ◽  
Durability Assessment ◽  
Reduce Emissions ◽  
Control Technologies

The Navy pilot program investigated cost-effective technologies to reduce emissions from legacy marine engines. High-speed, high-population engine models in both commercial and Navy fleets were targeted. Emission reductions were sought that would minimize fuel penalty as well as installation and operating costs. Navy operating conditions and fuels limited options. Five highly rated technologies were laboratory tested on a Detroit Diesel Corporation 12V-71N engine using two military and three alternative fuels. Two control technologies were then shipboard tested (baseline, 1-year early degradation, and 9-year late-life). Conclusions and recommendations are provided to inform application of these and similar emission control technologies within both commercial and Navy fleets.

Microstructure Properties and Strengthening Mechanisms of the AS4-3501-6 Polymeric Resin With Embedded Terfenol-D Particles

2014 ◽  
Author(s):  
Jamel H. Alexander ◽  
Oliver J. Myers
Keyword(s):  
Composite Laminates ◽  
High Speed ◽  
Volume Fraction ◽  
Critical Role ◽  
Weight Ratio ◽  
Polymeric Composite ◽  
High Strength ◽  
Polymeric Composites ◽  
Vital Role ◽  
Maintenance Cost

Polymeric composite laminates play a vital role in the fabrication of strong, lightweight materials. Composites also play a critical role in the aerospace and automotive industries. They are the very things that protect us from harsh environments. Due to widespread usage, it is important to understand how these materials age and perform over time. The advantages of polymeric composites are high rigidity, high strength to weight ratio, corrosion resistance, high fatigue strength, low thermal expansion, and manufacturability. The advantages of polymeric composite parts in machines and vehicles are low mass, high speed of operation, excellent fatigue resistance, quiet running due to shock absorption, easy installment and demounting, low maintenance cost, low energy costs during production and life cycle. Despite the advantages, there are concerns regarding the long-term durability of these composites especially when it comes to performances under critical and varying conditions. Since Terfenol-D, a magnetostrictive material will be placed in these polymeric composites for structural health monitoring, it is imperative to understand the microstructure of the particles and their net effect on the resin, e.g. distortions, volume fraction, and induced strain. Terfenol-D (Tb1−xDyxFe2) is of the cubic laves phase structure in which there is less plastic deformation which in turn makes the particles hard and brittle.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

An atomic-resolution microscope study of Al contracts on GaAs

1986 ◽  
Vol 44 ◽  
pp. 726-727
Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
High Speed ◽  
Schottky Contacts ◽  
Detailed Knowledge ◽  
The Past ◽  
Semiconductor Interfaces ◽  
Deposited Metal ◽  
Microwave Applications ◽  
Free Interfaces ◽  
Potential Use

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions

Scanning x-ray fluorescence microscopy and principal component analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1752-1753
Author(s):  
Brian Cross
Keyword(s):  
Principal Component Analysis ◽  
Fluorescence Microscopy ◽  
Spatial Resolution ◽  
High Speed ◽  
Image Acquisition ◽  
Principal Component ◽  
Fluorescence Microscope ◽  
Acquisition Rate ◽  
X Ray ◽  
Speed Up

A relatively new entry, in the field of microscopy, is the Scanning X-Ray Fluorescence Microscope (SXRFM). Using this type of instrument (e.g. Kevex Omicron X-ray Microprobe), one can obtain multiple elemental x-ray images, from the analysis of materials which show heterogeneity. The SXRFM obtains images by collimating an x-ray beam (e.g. 100 μm diameter), and then scanning the sample with a high-speed x-y stage. To speed up the image acquisition, data is acquired "on-the-fly" by slew-scanning the stage along the x-axis, like a TV or SEM scan. To reduce the overhead from "fly-back," the images can be acquired by bi-directional scanning of the x-axis. This results in very little overhead with the re-positioning of the sample stage. The image acquisition rate is dominated by the x-ray acquisition rate. Therefore, the total x-ray image acquisition rate, using the SXRFM, is very comparable to an SEM. Although the x-ray spatial resolution of the SXRFM is worse than an SEM (say 100 vs. 2 μm), there are several other advantages.

Image quality vs data obtainment in biological electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 42-43
Author(s):  
J. E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Image Quality ◽  
High Speed ◽  
Early Period ◽  
Early Years ◽  
Fluorescent Screen ◽  
Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

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