Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
This paper describes the harmonic analysis method which can be used to measure the resistance current of the metal oxide arrester (MOA) and the dielectric loss of the capacitive apparatus. The theory of this method and the requirement to the hardware circuit are introduced also. The testing and the analysis of the the…
Results of investigations performed in order to improve the current diagnostic techniques used for the evaluation of insulation systems of AC rotating machine stator windings are presented. Improvements come from the development of a new measuring system and the stochastic analysis of partial discharge (PD) pulse sign…
We have shown that reduction of deuterium permeation through AISI 316L stainless steel can be obtained by the deposition of an (Al,Ti)N coating: a 1.7-μm-thick coating was able to reduce the deuterium permeation flux by a factor 100–1000 in the 473–873 K temperature range. This result is related to the very low diffus…
This paper describes our theoretical and experimental approaches to the mechanisms responsible for electrical conduction at low and high fields, electrical aging, partial discharge and breakdown phenomena in insulating polymers. Electrical conduction always involves carrier injection from electrical contacts and subse…
This paper investigates the use of finite-difference time-domain (FDTD) models in the study of electrical discharges, particularly through the measurement of radiated signals. Support for electrostatic fields within the model is demonstrated. Signals radiated by a partial discharge pulse are simulated and found to be…
Accurate measurements of core loss for distributed-air-gap magnetic materials have traditionally been very difficult to obtain. Wattmeter measurements are affected by very small phase and time-delay measurement errors, while traditional calorimeters measure the sum of excitation winding loss and core loss. This paper…
The variations in the low frequency dielectric spectra of mass impregnated insulation depending on its moisture content have been investigated. For the calibration purposes a number of the impregnated paper samples was kept in the desiccators where different relative humidities were maintained. Thus obtained moisture…
We present experimental evidence for the existence of interlayer states formed in graphite-sulfur (C-S) composites. We have studied occupied and unoccupied p bands of the C-S composites by means of soft x-ray absorption and emission spectroscopy. New spectral features in the C $1s$ absorption are interpreted as contri…
An electrically reprogrammable resistor approach has been developed as a basis for a new nonvolatile memory that is potentially denser, faster, and easier to make than Dynamic RAM (DRAM). It relies on structural phase transitions induced by nanosecond-scale heating and cooling of small volumes of chalcogenide films wi…
This paper deals with the influence of continuous thermal aging on the dielectric and mechanical properties of Cross-Linked Polyethylene (XLPE) used as electrical insulation in high voltage cables manufactured by ENICAB (Algeria). In order to characterize the degree of the material degradation under thermal aging and…
This paper reports a dimethyl sulfoxide (DMSO) phase offered by a coordination polymer gel that consists of metal ions and a calixarene that has multiple binding sites. This metallogel, virtually 98% of which is DMSO, has high stability in aqueous solution over a wide range of pH (1−13), even at 100 °C, rejects ions (…
Ageing of insulation materials and systems may well be detected by quantitative measurements of their dielectric response. Such measurements can be performed in the frequency or time domain. In this contribution, a novel type of equipment based on relaxation current measurements is introduced which is designed for on-…
A very important aspect in chip design in flip chip technology is the heat dissipation. As the surfaces of the heat sink, the heat spreader and the chip are rough there are imperfect contacts leading to higher thermal resistance due to the contact resistance. A method to decrease this contact resistance is by the use…
Liquid crystals: main types and classification distribution functions and order parameters physical properties of liquid crystals nematic liquid crystals nematic liquid crystals - elastostatics and nematodynamics smectic liquid crystals liquid crystals of disc-like molecules polymer liquid crystals chiral liquid cryst…
We investigated near-infrared-to-blue upconversion from thulium (Tm3+) doped in tellurite glasses upon continuous wave excitation near 800 nm. We observed an enhancement of over two orders of magnitude of the upconverted emission at ∼480 nm when neodymium (Nd3+) ions were codoped with Tm3+ ions. For comparison, using…
This paper provides a review of thermoelectric cooling and its application to the cooling of electronic equipment. A background discussion of thermoelectric cooling is provided briefly citing early history, current developments, and the defining thermoelectric heat pumping equations. Several examples are provided of e…
Ultrathin 2-nm-thick carbon coatings are needed to increase the storage density in magnetic hard disks. We show how x-ray reflectivity, surface Brillouin scattering, resonant Raman scattering, and electron energy loss spectroscopy can measure consistently the structural and mechanical properties of these thin films. 2…
Piezoelectric constant and temperature vs dielectric constant measurements have been performed on the 〈001〉 and 〈011〉 oriented Pb(Mg1/3Nb2/3)O3–PbTiO3 crystals in the rhombohedral phase with compositions near the morphotropic phase boundary under different poling fields. The investigations have revealed that the diele…
A new technology is developed and demonstrated that couples anaerobic digestion of food scraps with production of biodegradable thermoplastics, polyhydroxyalkanoates (PHAs). The food wastes were digested in an anaerobic reactor producing four major organic acids. The concentrations of acetic, propionic, butyric, and l…
An electrical model for a Peltier cell, based on the analogy between thermal and electrical variables, is proposed. The use of thermal models allows the global performance of thermocooling circuit and signal system to be checked by using electrical circuit analysis programs such as SPICE. The maximum error in the stea…