Wireless sensor network (WSN) is comprised of tiny, cheap and power-efficient sensor nodes which effectively transmit data to the base station. The main challenge of WSN is the distance, energy and time delay. The power resource of the sensor node is a non-rechargeable battery. Here the greater the distance between the nodes, higher the energy consumption. For having the effective transmission of data with less energy, the cluster-head approach is used. It is well known that the time delay is directly proportional to the distance between the nodes and the base station. The cluster head is selected in such a way that it is spatially closer enough to the base station as well as the sensor nodes. So, the time delay can be substantially reduced. This, in turn, the transmission speed of the data packets can be increased. Firefly algorithm is developed for maximizing the energy efficiency of network and lifetime of nodes by selecting the cluster head optimally. In this paper firefly with cyclic randomization is proposed for selecting the best cluster head. The network performance is increased in this method when compared to the other conventional algorithms.
High-resolution X-ray diffraction and Raman scattering techniques have been used to analyse the impact of multiple energy hydrogen implantation with energy ranging from 40 to 120 keV on the structural properties of metal organic chemical vapour deposition grown unintentionally doped n-type Gallium Nitride (GaN) epitaxial layers. The full-width at half-maximum (FWHM) value of GaN rocking curves increases with ion dose indicating the damage in the crystal matrix due to hydrogen ion implantation. E2 (high) and A1(LO) Raman modes of GaN have been analysed. The behaviour of Raman shift, FWHM and area of GaN modes with H+ dose are explained on the basis of hydrogen substituting nitrogen atom, implantation-induced lattice damage and light attenuation by lattice damage in GaN layer. The influences of H+ implantation on the Raman mode parameters of sapphire substrate have also been analysed. 相似文献
ZnSe∶Mn nanocrystals were grown by chemical vapour transport method using the matrix of SiO2 aerogels. The cubic structure of the nanocrystals was confirmed by powder X-ray diffraction (XRD) and electron diffraction (ED) studies. The size of the crystals was observed using transmission electron microscope (TEM). The oxidation state of Mn in ZnSe nanocrystal was found using electron spin resonance (ESR) spectrum. The room temperature luminescence measurements show the peaks corresponding to both bandgap of the material and Mn in ZnSe. 相似文献
Twitter, the social network which evolving faster and regular usage by millions of people and who become addicted to it. So spam playing a major role for Twitter users to distract them and grab their attention over them. Spammers actually detailed like who send unwanted and irrelevant messages or websites and promote them to several users. To overcome the problem many researchers proposed some ideas using some machine learning algorithms to detect the spammers. In this research work, a new hybrid approach is proposed to detect the streaming of Twitter spam in a real-time using the combination of a Decision tree, Particle Swarm Optimization and Genetic algorithm. Twitter has given access to the researchers to get tweets from its Twitter-API for real-time streaming of tweet data which they can get direct access to public tweets. Here 600 million tweets are created by using URL based security tool and further some features are extracted for representation of tweets in real-time detection of spam. In addition, our research results are compared with other hybrid algorithms which a better detection rate is given by our proposed work. 相似文献
We have investigated the preventive effects of squalene against isoprenaline-induced myocardial infarction in male albino rats. Supplementation with squalene significantly prevented the isoprenaline-induced adverse changes in the levels of protein and glycoprotein components in plasma and heart tissue of experimental groups of rats. It exerted an antioxidant effect by inhibiting the isoprenaline-induced lipid peroxidation and by maintaining the level of non-enzymatic free radical-scavenger, reduced glutathione at near normalcy. Histopathological observations also confirmed the possible cardioprotective action of squalene by maintaining the normal architecture of the heart tissue. The results of the present investigation demonstrate that supplementation with squalene offers cardioprotection in experimental rats by its antioxidant and membrane- stabilizing properties. 相似文献
The Journal of Supercomputing - The Internet of Things (IoT) represents a potential paradigm increase in the number of linked devices, referred to as things. Administering these things remains a... 相似文献
To improve the dissolution properties of poorly water soluble active pharmaceutical ingredients (APIs), a solvent-free melt-absorption process was applied to directly load the APIs into mesoporous SBA-15 silica powder as an amorphous solid dispersion. Two model compounds, poorly aqueous soluble ibuprofen (IBU) and fenofibrate (FEN), were individually mixed with SBA-15 powder and heated above their respective melting points. Upon cooling, the physicochemical and solid-state properties of the solid dispersions were investigated by N2 adsorption, DSC, XRD, SEM and solid-state NMR. The molten API was found to be absorbed into the pores, confined within the nano-channels of SBA-15, and re-solidified to an amorphous solid dispersion. Due to the amorphous properties, the APIs showed a significant enhancement in dissolution rate as compared with the untreated crystalline APIs. Although the amorphous forms were not at thermodynamic equilibrium, the APIs exhibited excellent solid-state physical stability even under accelerated stress conditions. In comparison with APIs loaded using a co-spray drying process (previous work), the melt-absorption process required no organic solvent, produced powders with a coarser size distribution and more desirable flow properties. This solvent-free direct melt-absorption process can be used to formulate a wide range of poorly soluble drugs to be amorphous solid dispersions. 相似文献