A novel double-gate SOI MOSFET to improve the floating body effect by dual SiGe trench

In short-channel silicon-on-insulator metal-oxide-semiconductor transistors (SOI MOSFETs) the high electric field near the drain increases the floating-body effect. The aim of this article is to introduce a novel structure that reduces the electric field near the drain, so improving the floating-body effect. In the proposed structure, a dual trench is created in the buried oxide exactly under the junctions of drain/source and channel and is filled with an n-type SiGe material. The dual trench regions absorb the electric field lines and hence, the electric characteristic significantly improve. The proposed structure is named as dual SiGe trench double gate SOI MOSFET. In addition, we observe a considerable improvement in self-heating effects due to the higher thermal conductivity of SiGe in comparison with silicon dioxide.     

Momentum coefficient for promoting accuracy and convergence speed of evolutionary programming

Many practical problems culminate with solving optimization problems. Thus, many methods have been introduced for solving these types of problems. The need for algorithms that are fast and more accurate at finding global minimums is ever increasing. One of the promising methods is a heuristic and iterative method called Evolutionary Programming (EP). It is one of the computational methods used in optimization that is implemented for many practical applications. Many papers have shown the capability of this algorithm for addressing a variety of optimization problems. These studies have opened a vast new and interesting field of research. Recently, many methods have been proposed for promoting the performance of EP when finding the optimum point of functions or applications; however, EP has some shortcomings that cause slow convergence on some functions, especially multimodal functions. By overcoming these shortcomings, EP could be more effective in the optimization research field. This paper introduces new methods for overcoming these disadvantages and promoting the performance of EP. One of these methods, which has the best results on cost functions, changes the searching procedure by adding a new factor to produce offspring and pulling offspring toward a gathering point (the mean value of the parents). This method was tested on 50 well-known test functions discussed in the literature and was compared with state-of-the-art algorithms on twenty-two new cost functions. Finally, a hybrid method of CEP and MCEP (Momentum Coefficient Evolutionary Programming) called IMCEP (Improved Momentum Coefficient Evolutionary Programming) is introduced. The results of the calculations reported here show the efficiency of MCEP and IMCEP.     

An efficient Markov energy predictor for software defined wireless sensor networks

Wireless Networks - Software-defined wireless sensor networks (SDWSNs) are a great step forward to centralize and facilitate the management of low-power networks. However, the continuous sending of...     

A novel method for net-shape manufacturing of metal–metal sulfide cermets

Ceramic–metal composites (cermets) offer unique combinations of hardness and toughness, which make them attractive for a variety of applications. In this study, we propose a new method for the preparation of the metal–sulfur precursor mixture based on the ability to melt-cast the precursor mixture. We have used self-propagating high-temperature synthesis to produce a chromium/chromium sulfide cermet, exploiting the fact that this mixture of metal and sulfur can support the propagation of reactive waves. This ability, together with the properties of the reaction products (low gas evolution and liquid sulfide products), enables the net-shape synthesis of dense, near theoretical density product with a relatively simple and low-cost set-up. While the thermochemical calculations predict near-zero gas production for the chromium–sulfur system, the actual cermets showed a large amount of porosity (about 70 %), when synthesized at atmospheric pressure. The possible sources for porosity were identified, and the process improved to bring the porosity down to about 7 %. We also investigated the physical properties of the produced cermet with optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction techniques.     

Preparation,characterization, and in vitro bioactivity of magnetic co-polymer [N,N-dimethylaminopropylacrylamide-co-1-allylimidazole] as a new nanocarrier for delivery of cefotaxime

In this research, new magnetic nanoparticles (MNPs) conjugated radical co-polymerization with N, N-dimethylaminopropylacrylamide (N, N-DMAPAAm) as a thermosensitive monomer and 1-allylimidazole (AI) as a cross-linker agent was prepared as a magnetic nanocomposite (MNC). The synthesized MNC were characterized by Fourier transform infrared spectroscopy, Elemental analysis (CHN), Field emission scanning electron microscopy, Vibrating Sample Magnetometer, and Thermo Gravimetric Analysis. Cefotaxime was selected as a model drug and was loaded into the synthesized polymer. The main factors of adsorption process such as pH, contact time, temperature, and eluent were evaluated and optimized. The mechanism of cefotaxime adsorption is explained by Langmuir isotherm. Also, in vitro cefotaxime delivery in the simulated gastric and intestinal fluids was investigated. The drug release profile revealed that about 30.35% of the adsorbed cefotaxime was released in the first 30 min. at pH =1.2 (simulated gastric fluid) and 62.65% was released during 15 h at pH =7.4 (simulated intestinal fluid).     

A fast method to exactly calculate the diameter of incremental disconnected graphs

The breadth of problems requiring graph analytics is growing rapidly. Diameter is one of the most important metrics of a graph. The diameter is important in both designing algorithms for graphs and understanding the nature and evolution of graphs. Besides, the real world graphs are always changing. So detecting diameter in both static and dynamic graphs is very important. We first present an algorithm to calculate the diameter of the static graphs. The main goal of this algorithm is to reduce the number of breadth-first searches required to determine diameter of the graph. In addition, another algorithm is presented for calculating the diameter of incremental graphs. This algorithm uses the proposed static algorithm in its body. Based on experimental results, our proposed algorithm can detect diameter of both static and incremental graphs faster than existing approaches. To the best of our knowledge, the second algorithm is the first one that is able to efficiently determine the diameter of disconnected graphs that will be connected over time by adding new vertices.     

Effects of Ozone and Ozone/Hydrogen Peroxide on the Degradation of Model and Real Oil-Sands-Process-Affected-Water Naphthenic Acids

Naphthenic acids (NAs) are persistent compounds that contribute to the toxicity of oil sands process-affected water (OSPW). In this study, the effects of ozone and ozone/hydrogen peroxide on the NAs degradation in buffered water and OSPW were examined. Cyclohexanoic acid (CHA) was used as a model NAs compound in buffered water experiments at two different pHs, using radical scavengers. At pH 9, the addition of carbonate did not have any effect on CHA degradation. Additions of tert-butyl alcohol and tetranitromethane decreased the CHA degradation levels. For the OSPW experiments, degradation of acid-extractable fraction (AEF) and NAs was examined. Approximately 90% of AEF was oxidized in a semi-batch system. In a batch system, 99% of OSPW NAs were degraded. This study demonstrated that ozone and ozone/hydrogen peroxide could be suitable treatment processes for OSPW remediation.     

Direction of arrival accuracy improvement through estimation of spatial coherence loss function in non-homogeneous environments

Performance of direction of arrival (DOA) estimation is significantly degraded in practical situations. One of the conditions that decreases its performance, is the coherent loss caused by the propagation of the wavefront through random non-homogeneous media. Most of the previous methods, such as matrix fitting method and covariance matching technique, need the multidimensional search; therefore their computations are difficult and not suitable for a real-time application. In this paper, a three-stage method based on the generalised eigenvalues utilising signal subspace eigenvectors (GEESE) and Gauss–Newton (GN) algorithms, namely 3SM/GE-GN, is presented. Simulation results show the effectiveness of the proposed method. Difference of RMSE of DOA estimation between proposed method, which is independent of the coherent loss, and other methods is more clearly visible in higher snapshots. As well, in fixed snapshot, the RMSE of the proposed method is lower than others in different SNRs. Furthermore, the computational time of the simulation is very lower than two previous works.