scholarly journals Atmospheric and Long-term Aging Effects on the Electrical Properties of Variable Thickness WSe2 Transistors

2018 ◽  
Vol 10 (42) ◽  
pp. 36540-36548 ◽  
Author(s):  
Anna N. Hoffman ◽  
Michael G. Stanford ◽  
Cheng Zhang ◽  
Ilia N. Ivanov ◽  
Akinola D. Oyedele ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Variable Thickness ◽  
Aging Effects

Polyimide Copolymers Containing Various Levels Of The 6F Moiety For High Temperature And Microelectronic Applications

1991 ◽  
Vol 227 ◽  
Author(s):  
M. Haider ◽  
E. Chenevey ◽  
R. H. Vora ◽  
W. Cooper ◽  
M. Glick ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Electrical Properties ◽  
Oxidative Stability ◽  
Trifluoromethyl Group ◽  
Thermal And Mechanical Properties

ABSTRACTTrifluoromethyl group-containing polyimides not only show extraordinary electrical properties, but they also exhibit excellent long-term thermo-oxidative stability. Among the most thermomechanically stable structural polyimides are those from 6F dianhydride (6FDA) and 6F diamines. The effects of substituting non-fluorine containing monomers such as BTDA, mPDA and 4,4′-DADPS for the hexafluoroisopropylidene monomers on the dielectric, thermo-oxidative, thermal and mechanical properties of the copolymers were studied.

scholarly journals Results of Analysis of Aging Related Events at Ukrainian NPPs

2020 ◽  
pp. 44-51
Author(s):  
O-i Shugailo ◽  
O. Ligotskyy ◽  
O. Pecherytsia ◽  
O. Kulman ◽  
R. Moskalyshyn ◽  
...  
Keyword(s):  
Nuclear Energy ◽  
Maximum Efficiency ◽  
Operational Experience ◽  
Aging Effects ◽  
Term Operation ◽  
Operation Period ◽  
Periodic Safety ◽  
Nuclear Installation ◽  
Main Factors

The design lifetime (30 years) of Ukrainian NPPs has already been expired or will be expired soon. One of the priority areas for the development of nuclear energy is long-term operation (LTO) based on the results of periodic safety review. At present, eleven Ukrainian NPP units are operated under LTO conditions, which in turn causes certain features of operation related to wear, fatigue and general aging of components and structures. An issue of aging management is considered one of the main factors to ensure the safety of a nuclear installation, both in the design lifetime and in the long-term operation. The primary purpose of aging management is to ensure the safety and maximum efficiency of operation through the implementation of technically and economically feasible measures aimed at timely detection and keeping of degradation of NPP components caused by aging within the limits. One way to determine the efficiency of implemented measures and aging management programs is to analyze operational experience and, in particular, analyze the number of NPP operational occurrences during the design and long-term operation period and that are directly related to the aging effects. This paper presents the results of the analysis of the events at Ukrainian NPPs caused by aging processes, compares the results of national and international experience.

EXPERIMENTAL INVESTIGATION OF THE DURABILITY OF LOAD BEARING TIMBER-GLASS COMPOSITES UNDER THE EFFECTS OF ACCELERATED AGING

2019 ◽  
Vol 14 (2) ◽  
pp. 45-59 ◽  
Author(s):  
Halet Almila Arda Buyuktaskin ◽  
Mehmet Serkan Yatagan ◽  
Gulseren Erol Soyoz ◽  
Leyla Tanacan ◽  
Morvarid Dilmaghani
Keyword(s):  
Raw Materials ◽  
Accelerated Aging ◽  
Structural Elements ◽  
Atmospheric Conditions ◽  
Aging Effects ◽  
Glass Composite ◽  
Load Bearing ◽  
Glass Composites ◽  
Before And After

Although timber was used extensively as a structural material for traditional buildings in Turkey in the past, usage of structural timber decreased significantly over time and timber has been largely replaced by other materials. As timber is a natural, durable and sustainable material, it would be desirable to re-introduce timber structural elements to contemporary construction in a form that is appealing to industry. Timber-glass composite structural elements are potentially a good candidate for this purpose. To that end, a series of tests were conducted on load-bearing timber-glass composites in order to understand the long–term structural performance of the composite material under atmospheric conditions; to decrease the recurring cost of repair and maintenance; and to minimize the exhaustion of raw materials and energy. In this paper, the first part of this experimental work is presented, which focuses on the durability of timber-glass composite under the effects of accelerated aging, carried out on small-sized timber-glass composite specimens. Accelerated aging effects were observed under wetting-drying, freezing-thawing, UV effects, resistance to acids and high temperature. The mechanical strength of the timber-glass composite specimens before and after the effect of accelerated aging was measured by adhesion and shear strength tests and a comparative analysis of the results was carried out. The results of the experiments indicate that timber-glass composite is suitable to be used under protection from environmental conditions.

Mitigation of High Temperature Environments on Electrical Disconnects

2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000148-000153
Author(s):  
Kenneth P. Dowhower
Keyword(s):  
High Temperature ◽  
Electrical Properties ◽  
Stress Relaxation ◽  
Surface Treatment ◽  
Material Properties ◽  
Mechanical Stability ◽  
Contact Interface ◽  
Insulating Materials ◽  
Temperature Applications

Abstract The electrical interconnect is an essential component of most electrical system configurations. The ability of the interconnect interface to reliably transmit power and / or data throughout the system is critical to its overall performance. Degradation of the mechanical or electrical properties of the interface can reduce the system performance or in severe cases, make it inoperable. There are several factors which can inhibit the performance of the interconnect, one of most severe is long term exposure to elevated temperatures. This effect can also be accelerated when combined with other severe environmental conditions such as high vibration and physical shock, which are often found in down hole oil and gas well drilling applications. This type of exposure can significantly degrade the essential properties of a reliable electrical interface such as contact resistance, mechanical stability, and electrical isolation. This paper will present options for design features and material properties that can be incorporated into an interconnect design that will mitigate these adverse effects. Specifically, this paper addresses the material properties of the contact interface and its surface treatment, the mechanical and electrical properties of the insulating material, the robustness of the mating features and the contact retention system. Two key features of the contact interface that are discussed are the stability of its electrical resistance and the robustness of its mechanical retention. Long term exposure to high temperatures typically induces stress relaxation in the compliant members of the contact interface that are required to produce a stable, low resistance interface, while allowing for a high level of mate / unmate durability. Stress relaxation can also reduce the mechanical stability of the contact interface where metal or plastic retention features are utilized. In the case of retention through epoxy bonding, imparting thermal stress at the bonding surface can result in loss of adhesion and / or retention. The surface treatment of the contact interface has also been shown to be a contributing factor in its electrical stability in high temperature applications. Typically, the interface is plated with a hard gold over nickel finish, which provides a noble interface that is corrosion resistant, but with the hardness required to withstand many mate / unmate cycles. A small percentage of nickel or cobalt are typically alloyed with the gold to produce the required hardness. In most applications, it has minimal impact on the overall resistance of the contact interface. In high temperature applications, however, it can tend to diffuse through the gold to the contact interface. Since these materials have a higher resistivity, they can negatively affect the resistance of the interface. The impact of this effect is reviewed in this paper. Finally, results of the evaluations on high temperature insulating materials and bonding epoxies are presented in this paper. The mechanical and dielectric stability of the insulating materials and the adhesion properties of the epoxy used for contact retention were the primary concerns for their evaluation. The verification tests that included at temperature exposure were conducted at +260°C to simulate extreme use cases for most down hole applications.

Sulfur-modified biochar as a soil amendment to stabilize mercury pollution: An accelerated simulation of long-term aging effects

2020 ◽  
Vol 264 ◽  
pp. 114687 ◽  
Author(s):  
Bin Zhao ◽  
David O’Connor ◽  
Zhengtao Shen ◽  
Daniel C.W. Tsang ◽  
Jörg Rinklebe ◽  
...  
Keyword(s):  
Soil Amendment ◽  
Mercury Pollution ◽  
Aging Effects ◽  
Accelerated Simulation ◽  
Modified Biochar

Adhesion, Reaction and Stability of Metal/Polyimide Interfaces

1989 ◽  
Vol 167 ◽  
Author(s):  
J. Kim ◽  
S. P. Kowalczyk ◽  
Y. H. Kim ◽  
N. J. Chou ◽  
T. S. Oh
Keyword(s):  
Electrical Properties ◽  
Chemical Bond ◽  
Adhesion Strength ◽  
Interfacial Reactions ◽  
Great Care ◽  
Metal Interface ◽  
Term Stability ◽  
Long Term Stability ◽  
Mechanical And Electrical Properties

AbstractInterfacial reactions of polyimide with several metals have been investigated by XPS and TEM to determine their effects on adhesion and long term stability. It has been found that the polyimide-on-metal interface and the metal-on-polyimide interface are intrinsically different; in the case of PI-on-metal interface, the precursor of polyimide, polyamic acid, reacts with the metal resulting in a strong chemical bond and therefore, higher adhesion strength than the corresponding metal-on-PI interface. Both interfaces are found susceptible to T/H environment, resulting in significant adhesion loss. The mechanical and electrical properties of polyimide may be altered as a result of the interaction with metals and therefore, great care is necessary to insure a stable interface and the reliability of devices.

Recovery of the soleus muscle after short- and long-term disuse induced by hindlimb unloading: effects on the electrical properties and myosin heavy chain profile

2005 ◽  
Vol 18 (2) ◽  
pp. 356-365 ◽  
Author(s):  
Jean-François Desaphy ◽  
Sabata Pierno ◽  
Antonella Liantonio ◽  
Annamaria De Luca ◽  
M. Paola Didonna ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Myosin Heavy Chain ◽  
Soleus Muscle ◽  
Heavy Chain ◽  
Hindlimb Unloading ◽  
Short And Long Term

Long-term aging effects on tensile characterization of steel fibre reinforced concrete

2016 ◽  
Vol 17 (6) ◽  
pp. 1082-1093 ◽  
Author(s):  
Thomaz Eduardo Teixeira Buttignol ◽  
Matteo Colombo ◽  
Marco di Prisco
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Fibre Reinforced Concrete ◽  
Aging Effects ◽  
Steel Fibre Reinforced Concrete ◽  
Tensile Characterization
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