The effect of moisture on the material behavior of Magnamite® IM7 Graphite/Avimid® K3B thermoplastic polyimide composite laminates has been investigated. Laminates consisting of a 62 vol% fiber were laid up ...
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The phase behavior of blends of zinc sulfonated polystyrene (ZnSPS) and bisphenol-A polycarbonate (PC) was studied as a function of the sulfonation level and the molecular weight of the ZnSPS ionomer. The system exhib...
The phase behavior of blends of zinc sulfonated polystyrene (ZnSPS) and bisphenol-A polycarbonate (PC) was studied as a function of the sulfonation level and the molecular weight of the ZnSPS ionomer. The system exhibits upper critical solution temperature (UCST) behavior. The cloud point temperatures increased with increasing ZnSPS molecular weight and decreased with increasing sulfonation level. No strong interactions between ZnSPS and PC were detected by FTIR. The composition dependence of the glass transition temperatures of the miscible blends exhibited negative deviation from linear additi vity, which is consistent with no or weak interactions between ZnSPS and PC. Miscibility is believed to arise from strong repulsive interactions between the charged and uncharged species on the ionomer chain.
It is of critical importance to safety in the nuclear power industry to estimate the lifetime of polymeric materials in an environment featuring elevated temperatures and radiation. To this end, the authors are examin...
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It is of critical importance to safety in the nuclear power industry to estimate the lifetime of polymeric materials in an environment featuring elevated temperatures and radiation. To this end, the authors are examining the aging of polymeric materials, in cables and other components in nuclear reactor containments by comparing aging processes for a variety of materials under natural conditions with those under accelerated laboratory conditions typical of those used in qualification. The physical property data derived from naturally and artificially aged specimens are compared using three methods: (1) a traditional method; (2) activation energy from natural data alone; and (3) an internal standards method. All three methods work with the properties of the material in its aged, but usable state, and not with a failure time of the material.
The advantages of single electron device with asymmetrical tunnel barriers (ATBs), proposed by the authors((1)), over conventional single electron device with symmetrical tunnel barriers (STBs) are discussed referring...
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ISBN:
(纸本)0780333942
The advantages of single electron device with asymmetrical tunnel barriers (ATBs), proposed by the authors((1)), over conventional single electron device with symmetrical tunnel barriers (STBs) are discussed referring the features of ATBs and the results of computer simulation of the performance of tunnel-junction-load SET logic and turnstile devices. Experimental observation of Coulomb staircase and asymmetrical tunnel characteristic in ATBs fabricated with GaAs/AlGaAs heterostructure is also reported.
The advantages of single electron devices with asymmetrical tunnel barriers (ATBs), proposed by the authors, over conventional single electron devices with symmetrical tunnel barriers (STBs) are discussed by referring...
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The advantages of single electron devices with asymmetrical tunnel barriers (ATBs), proposed by the authors, over conventional single electron devices with symmetrical tunnel barriers (STBs) are discussed by referring to the features of ATBs and the results of computer simulation of the performance of tunnel-junction-load SET logic and turnstile devices. Experimental observation of a Coulomb staircase and asymmetrical tunnel characteristics in ATBs fabricated with GaAs/AlGaAs heterostructures are also reported.
Sulfonation of poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene), PEEK, improves its miscibility with poly(ϵ-caprolactam), Nylon-6 ( N 6). This article describes the thermal transitions and the specific i...
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Commercial samples of atactic polypropylene (aPP) and polyvinyl methyl ether (PVME) were purified and spin-cast onto glass coverslips with a view to using these as model surfaces in thrombogenicity studies. These mate...
The development of an oriented noncrystalline phase in a semicrystalline polymer filament has been studied via X-ray scattering. These unique PET fibers contain a relatively high noncrystalline content and also have h...
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Horseradish peroxidase (HRP) was effectively entrapped in a novel composite membrane of poly(vinyl alcohol) and regenerated silk fibroin. IR spectroscopy was employed to characterize the structure of the composite mem...
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Horseradish peroxidase (HRP) was effectively entrapped in a novel composite membrane of poly(vinyl alcohol) and regenerated silk fibroin. IR spectroscopy was employed to characterize the structure of the composite membrane and scanning electron microscopy was used to visualize the morphology of the composite membrane. HRP was utilized to amplify the amperometric response of the sensor by catalyzing reduction of hydrogen peroxide via nickelocene, an electron transfer mediator between immobilized HRP and a glassy carbon electrode. The influence of various experimental parameters such as pH, temperature and applied potential were explored for optimum analytical performance. The sensor possessed a variety of characteristics including good sensitivity, rapid response time and a low detection of limit of 0·1 μmol dm −3 , which arose from the efficiency of electron transfer between immobilized HRP and the electrode via nickelocene.
A simple arithmetic procedure was developed in order to be able to band-ratio dichroic measurements from simple attenuated total reflection (ATR)-IR spectroscopy to measure the surface molecular orientation of any pol...
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A simple arithmetic procedure was developed in order to be able to band-ratio dichroic measurements from simple attenuated total reflection (ATR)-IR spectroscopy to measure the surface molecular orientation of any polymer showing dichroism. This development eliminates the need to get a reproducible contact area or a reference band which does not show dichroism upon drawing. This method is universally applicable to any material showing dichroic IR bands. No assumptions are made regarding the structure of the sample in order to calculate the dichroic ratio. Furthermore, no special attachments are required for the dichroic measurements.
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