The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Using absorption materials to reduce RF heating during MRI procedure is studied in this paper. Materials with different electromagnetic absorption characteristics are used to alter the EM and current distributions on the device. Consequently, the RF induced heating behaviors of external fixation devices can be reduced. Numerical and experimental studies are provided to demonstrate the potentials of...
Thin and flexible freestanding graphene nanoplatelets (GNPs)-based paper-like materials are fabricated and experimentally characterized to assess their employment as radiofrequency electromagnetic interference shields. Samples are obtained by vacuum filtration of ultrasonicated suspensions. Different suspensions are prepared by mixing either acetone/DMF or acetone/NMP and worm-like exfoliated graphite...
A multi-physics model is developed based on P2D model, including the electrochemical part, thermal part and the temperature distribution. It can simulate the physical and chemical phenomena from the scale of the active particles to the scale of whole battery. The charging optimization is also investigated, two internal characteristics, which can only be calculated by the proposed model, are treated...
This work investigates the fundamental properties of armchair single-wall carbon nanotubes (armchair-SWCNTs) dipole antenna at THz band using Drude method. Due to their metallic conducting properties, the armchair SWCNTs will be utilized in this work. The radiation pattern, s11 parameters, phase velocity and antenna directivity are presented for this antenna. The results demonstrate that armchair-SWCNTs...
Metasurfaces have paved the way for compact and flat electromagnetic systems with properties not readily available in nature. Graphene, naturally occurring two-dimensional material, may serve as a candidate for fully functional flatland photonics. Here we exploit the unique electronic properties of graphene and suggest a paradigm for a single-layer nonreciprocal graphene-based metasurface with extreme...
In the last decade, we have experienced a fascinating transformation in the research and development of atomically thin-layered material (ATLM) systems. Graphene and its compounds have enabled the development of novel devices for a wide variety of applications in an extremely short period of time. In addition, non-graphene ATLMs have recently been utilized to produce devices with exceptional performances...
Estimating the contact resistance and losses of Carbon-Nanotubes based devices is a challenging task. This work presents an effective model to calculate the contact resistance of single-walled carbon nanotube-based RF devices. The model realistically incorporates operational parameters beyond the quantum limits and it makes it feasible to implement the model in commercially-adopted COMSOL simulators...
Characterizing and tracking electrical conductivity, magnetic permeability and thermal conductivity in conductive material have promising potential for the detection and evaluation of material state undertaken by fatigue or residual stress. This letter proposes a spatial-transient-stage tensor mathematical model of eddy current pulsed thermography system and Tucker decomposition algorithm for characterizing...
Microvaristors are used particularly as lightning arrestors. In another case, they are used as the electrical field grading materials. Additionally, we especially focused on their low volume resistance at the composite material of the microvaristors to use it as the anti-electrostatic coating. In the previous study, we found a solution to disperse microvaristors uniformly. In that study, we used semi-conductive...
Polyethylene (PE) and oil impregnated paper are widely used as insulation materials in high voltage power equipment however, at high voltages the space charge inside the insulating material can distort the electric field distribution and thus greatly influence aging and degradation. Moreover, there is usually a temperature gradient across the insulation when the equipment is in service, and this can...
Most carbon nanomaterials are touted for their unusual conductive or semiconductive properties. In this paper, we compare the many-layered graphene oxide (GO) and GO-silver nanocomposite “papers” to elucidate their unusual resistive properties. We have observed significant nonlinearities in resistivity, its dependence on temperature, and current-induced effects on the resistivity of these materials.
Thermoelectric (TE) microcoolers are solid state devices widely considered as strong candidates for precise temperature control and spot cooling in microelectronic circuits, especially for temperature sensitive devices such as laser diodes.
In paragraph are presented the results of research based on the AC conductivity of the wet oil-impregnated insulating paper, depending on the moisture content and temperature of the samples. This is a new experimental method, which converts the results from the FDS to the reference temperature of 293.15 K (20 ° C). Takes account of the activation energy for conduction and relaxation time
Thermal issues increase with the electronic industry pushing towards fast in high speed, high density, and high performance. Thermal conductive materials are strongly demanded for increasing heat dissipation and reducing operating temperature of devices. Hexagonal boron nitride (h-BN) nanosheet that owns high thermal conductivity and low coefficient of thermal expansion is a good filler candidate...
Thermal interface materials (TIMs) which consist of metal foil and soft cushion are used in the process of chip processor platform validation (PPV) process, and some defects, such as the stains caused by debris peeled off from TIMs due to stress concentration, were found on the surface of the chips and they had an hazardous influence in the testing process. As well as that, the thermal resistance...
According to Moore's Laws, complexity and power densities of electronic devices are increased during the last decades, moreover their dimensions are shrinking to nanometers causing hot-spot temperature escalation. Thermal management, therefore, becomes a critical issue for next generation of electronics. This scenario motivates development of novel thermal conductive adhesive (TCA) with enhanced thermal...
To meet the requirements for future fine pitch and high-performance interconnects in advanced packaging, ICAs with nano-materials are attracting more and more interest due to their specific electrical, mechanical and optical properties. There has been extensive research on nano-conductive adhesives containing nanofillers such as nanoparticles, nanowires or carbon nanotubes. In this paper, copper nanoparticles...
Eddy current measurements are widely used for non-destructive testing and identification of the electrically conductive materials (e.g. metals and alloys) and structures of such materials, also in aerospace industries. As well, new application fields are interesting, like monitoring of the composites, including electrically conductive carbon-fibres inside the structures. One challenge is the precise...
Consumer electronics such as portable devices (laptops, smartphones) become smaller, thinner and more powerful. In such devices a passive cooling begins to play a dominant role in heat dissipation process. In passive cooling systems thermal resistance of thermal path between semiconductor junction and radiator should be progressively reduced. It can be done by application of efficient (high thermal...
Reliability testing of thermally conductive, high-temperature, high-dielectric strength materials was conducted using newly developed high-temperature thermal conductivity and high-dielectric breakdown voltage characterization instruments based on ASTM Standards. These instruments and tests were used for optimizing thermal conductivity and dielectric breakdown of Bismaleimide Resin (BMI) - Boron Nitride...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.