The effect of components' thermal properties in addition to their geometric configuration on the developed thermal stress in a model printed circuit board (PCB) is investigated. This effect is quantified through three parameters, the average normalized temperature gradient, maximum normalized temperature gradient and the uniformity factor. It is found that the effect of the geometric configuration, especially that of the heat-generating component, is more significant than the thermal properties of the components. © 2019 IEEE.

Recently, perovskite solar cells (PSCs) exhibits tremendous power conversion efficiency and has shown enhanced figures of merit being secured regarding cell stability. In this paper, perovskite solar cell with Zno electron injection layer is presented. The humidity degradation of the perovskite active layer and the efficiency of the cell is observed under several conditions. Using ZnO as a planner electron injection layer (EIL) instead of TiO2, the efficiency of the device significantly improved, showing low-resistance shunting pathways. Also, polydimethylsiloxane (PDMS) has been used as a

As on-chip integration increases, the thermal distribution becomes spatially non-uniform and varies based on the power dissipation. In this paper, we introduce a temperature-aware task-mapping algorithm to prevent hotspots and achieve a highly uniform thermal distribution using adaptive multi-threshold values. The algorithm monitors the temperature of the cores, swaps tasks when the temperature of the core is relatively higher than the average temperature of the chip. Cores are switched off if they exceed an absolute maximum temperature. Using this algorithm, reliability is enhanced by

Non-aggregated magnetite nanorods with average diameters of 20-30 nm and lengths of up to 350 nm were synthesized via in situ, template free hydrothermal technique. These nanorods capped with different concentrations (1, 1.5, 2 and 2.5 g) of nicotinic acid (vitamin B3); possessed good magnetic properties and easy dispersion in aqueous solutions. Our new synthesis technique maintained the uniform shape of the nanorods even with increasing the coating material concentration. The effect of nicotinic acid on the shape, particle size, chemical structure and magnetic properties of the prepared

Magnetite nanoparticles of controlled shape and dimensions were synthesized using a modified hydrothermal technique. The influence of different synthesis conditions on the shape, size (length and diameter), structure and magnetic properties of the prepared nanoparticles is presented. The mineral phases, the morphologies, size distribution of the resulting magnetic nanoparticles and their magnetic properties were characterized using different characterization methods. We designed magnetite nanoparticles with different morphologies (nanospheres, nanorods, nanocubes and hexagons) and with

Carbon nanofibers (CNFs) possess superior catalytic abilities and high surface area. Moreover, energetic particles can be loaded on them by acting as carriers. The current study reports an electroless plating, effective deposition of copper particles (Cu) on the surface of CNFs. The prepared Cu–CNFs hybrid was annealed at 250 °C to form CuO–CNFs. Homogeneous loading of CuO particles on CNFs was revealed via TEM analysis, while the crystalline structure was studied using XRD analysis. In addition, ammonium perchlorate (AP) oxidizer with endothermic initial decomposition was mixed with the

The wooden industry depends heavily on logging activities which have negative impacts on the environment and a shortage of supply. The industry is starting to depend on composite boards from agricultural waste materials. Composite boards have been shown in the literature. However, some wooden applications still depend on hardwoods. Besides, most of these composite boards use synthetic formaldehyde as binders. Formaldehydes have negative impacts on human health. On the other hand, Egypt has an abundance of cotton waste that can produce composite woods. In this paper, the researchers compared

In this paper, we investigate the maximum throughput of a saturated rechargeable secondary user (SU) sharing the spectrum with a primary user (PU). The SU harvests energy packets (tokens) from the environment with a certain harvesting rate. All transmitters are assumed to have data buffers. In addition to its own traffic buffer, the SU has a buffer for storing the admitted primary packets for relaying; and a buffer for storing the energy tokens harvested from the environment. We propose a new cooperative cognitive relaying protocol that allows the SU to relay a fraction of the undelivered

Composite beads composed of chitosan (CS) with different carbon nanotubes (CNTs) were prepared by the incorporation of single-walled carbon nanotubes (SWCNTs), multiwalled carbon nanotubes (MWCNTs), and carboxylic multiwalled carbon nanotubes (MWCNT-COOHs). A protected crosslinking method was used for the preparation of the CS/CNTs beads by the reaction of the beads with Hg(II) as the protector. Scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to characterize the prepared beads. The adsorption performance of the prepared beads was

Water scarcity is now a serious global issue resulting from population growth, water decrease, and pollution. Traditional wastewater treatment plants are insufficient and cannot meet the basic standards of water quality at reasonable cost or processing time. In this paper we report the preparation, characterization and multiple applications of an efficient photocatalytic nanocomposite (CoxNi1−xFe2O4; x = 0.9/SiO2/TiO2/C-dots) synthesized by a layer-by-layer method. Then, the photocatalytic capabilities of the synthesized nanocomposite were extensively-studied against aqueous solutions of