Co-deposition process of RF-Sputtering and RF-PECVD of copper/carbon nanocomposite films

Nanoparticle copper/carbon composite films were prepared by co-deposition of RF-Sputtering and RF-PECVD method from acetylene gas and copper target. We investigate deposition process in the region where by changing pressure, the process converts to physical sputtering mode in constant power regime and at a critical pressure between 1.5 to 3 Pa. The estimated value of mean ion energy at this critical point of pressure is close to threshold energy of physical sputtering of copper atoms by acetylene ions. By utilizing this property and by setting initial pressure from 1.3 to 6.6 Pa, nanoparticles copper/carbon composite films were grown with different copper content. The Copper content of our films was obtained by Rutherford Back Scattering (RBS) and it varied from 2% to 97%. The copper content of the surface was obtained by X-ray Photoelectron Spectroscopy (XPS). The results of XPS at different stages of the growth and copper oxidization confirm our suggested mechanism of deposition. Atomic force microscopy (AFM) image and X-ray diffraction (XRD) indicated that copper nanoparticles were formed in our films.     

Throughput analysis of wireless-powered decode-and-forward relay systems with interference

Wireless Networks - This paper investigates the throughput of a wireless-powered dual-hop relaying system with the presence of co-channel interference. Specifically, an energy-constrained source...     

Optical absorption engineering in dispersive band structure of MWCNTs array:design and optimization of total absorber for NIR to MIR regime

In this paper, we design a total infrared (IR) absorber based on a dispersive band structure of two-dimensional (2D) multiwall carbon nanotube (MWCNTs) square array working from near IR (NIR) to mid IR (MIR) regime. The absorption characteristics have been investigated by the 2D finite-difference time domain (FDTD) method in square lattice photonic crystal (PC) of the multipole Drude-Lorentz model inserted to the dispersive dielectric function of MWCNTs. Dispersive photonic band structure and scattering parameters for the wide range of lattice constants from 15 nm to 3 500 nm with various filling ratios have been calculated. The results show that for large lattice constant (>2 000 nm), the Bragg gap moves to the IR regime and leads to MWCNTs arrays acting as a total absorber. For a structure with lattice constant of 3 500 nm and filling factor of 12%, an enhanced absorption coefficient up to 99% is achieved in the range of 0.35 eV (λ=3.5 μm) nominated in the MIR regime. Also, the absorption spectrum peak can be tuned in the range of 0.27—0.38 eV (λ=4.59—3.26 μm) with a changing filling factor. Our results and methodology can be used to design new MWCNTs based photonic devices for applications like night-vision, thermal detector, and total IR absorbers.     

Hunger alters the expression of acquired hedonic but not sensory qualities of food-paired odors in humans.

To test whether expression of hedonic and sensory odor qualities acquired by association with sweet and bitter tastes depend on hunger state, hungry volunteers experienced odors paired with sucrose, quinine, or water and then were tested under different hunger states manipulated with energy preloads. Acquired liking for sucrose-paired odors was evident following a low-energy or control preload but not a high-energy preload; however, odor sweetness increased in all preload conditions. Acquired dislike and increased bitterness of quinine-paired odors were independent of preloading. These data demonstrate hunger-dependent expression of acquired liking for flavors through flavor-flavor associations in humans and demonstrate independence between acquired hedonic and sensory qualities of odors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forest biomass supply logistics for a power plant using the discrete-event simulation approach

This study investigates the logistics of supplying forest biomass to a potential power plant. Due to the complexities in such a supply logistics system, a simulation model based on the framework of Integrated Biomass Supply Analysis and Logistics (IBSAL) is developed in this study to evaluate the cost of delivered forest biomass, the equilibrium moisture content, and carbon emissions from the logistics operations. The model is applied to a proposed case of 300 MW power plant in Quesnel, BC, Canada. The results show that the biomass demand of the power plant would not be met every year. The weighted average cost of delivered biomass to the gate of the power plant is about C$ 90 per dry tonne. Estimates of equilibrium moisture content of delivered biomass and CO₂ emissions resulted from the processes are also provided.     

Clinical implications of attentional bias in anxiety disorders: An integrative literature review.

Research on information processing biases has been motivated by the hope that it would lead to new and more efficient psychotherapeutic interventions. The literature is abundant with empirical data of attentional biases toward threat stimuli in anxiety disorders. This article aims to review the existing literature on the topic of attentional bias in anxiety disorders and discuss important implications for clinical practice. We adopted an integrative approach to link research data on attentional bias, information processing, and cognitive accounts (automaticity and controllability) with clinical practice in cognitive-behavioral therapy. It is important to develop and apply therapeutic interventions that can effectively reduce negative attentional biases while treating the main problems associated with anxiety disorders. However, it remains to be seen whether cognitive therapy interventions targeting more voluntary, strategic information processing can have a positive impact on automatic, involuntary processing involved in attentional biases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance Analysis of Generic Amplify-and-Forward Cooperative Networks over Asymmetric Fading Channels

In this paper, we analyze the performance of multi-hop multi-branch amplify-and-forward (AF) networks over generalized fading channels. Using the moment generating function (MGF)-based approach, we develop general expressions for the outage probability and symbol-error rate (SER) performance of the system with maximal ratio combining (MRC) receiver. The MGF-based approach relies on numerical integration. To gain insights into system performance, we therefore investigate the asymptotic outage and SER performance of the system with MRC and selection combining (SC) receiver at the destination. In particular, we develop the asymptotic statistics of the end-to-end signal-to-noise ratio (SNR) of an AF multi-hop link. We further derive the cumulative density function of the sum of the individual end-to-end SNRs, received from different diversity paths for MRC receiver. We also study the power allocation problem in a multi-hop multi-branch system with MRC receiver. In generalized Gamma fading environments, we seek to find the power allocation strategy that maximizes the SNR at the destination subject to a total power constraint. By means of simulations, we validate our theoretical developments and verify the efficiency of our proposed power allocation in improving the received SNR compared to a generic cooperative system with no power allocation. We also conclude that our asymptotic expressions for the outage probability and SER match the simulations very well in medium-to-high-SNR regime.     

A Low Complexity PAPR Reduction Architecture for OFDM-DSCK Communication System

Wireless Personal Communications - In this paper, a merit factor-based method is introduced for peak to average power ratio (PAPR) reduction of Orthogonal Frequency Division Multiplexing-based...     

A differential binary message-passing LDPC decoder

In this paper, we propose a binary message-passing algorithm for decoding low-density parity-check (LDPC) codes. The algorithm substantially improves the performance of purely hard-decision iterative algorithms with a small increase in the memory requirements and the computational complexity. We associate a reliability value to each nonzero element of the code's parity-check matrix, and differentially modify this value in each iteration based on the sum of the extrinsic binary messages from the check nodes. For the tested random and finite-geometry LDPC codes, the proposed algorithm can perform as close as about 1 dB and 0.5 dB to belief propagation (BP) at the error rates of interest, respectively. This is while, unlike BP, the algorithm does not require the estimation of channel signal to noise ratio. Low memory and computational requirements and binary message-passing make the proposed algorithm attractive for high-speed low-power applications.     

Using an enhanced scatter search algorithm for a resource-constrained project scheduling problem

The resource-constrained project scheduling problem is one of the classical problems in the field of operations research. There are many criteria to efficiently determine the desired schedule of a project. In this paper, a well-known criterion namely project’s makespan is considered. Due to the complexity of the problem, it is very difficult to obtain optimum solution for this kind of problems by means of traditional methods. Therefore, an enhanced scatter search, based on a new path relinking and two prominent permutation-based and crossover operators, is devised to solve the problem. In order to validate the performance of the proposed algorithm, in terms of solution quality, the algorithm is applied to various test problems available on the literature and the reliability of it, is compared with well-reported benchmark algorithms. The computational results reveal that the proposed algorithm has appropriate results in comparison with the existing benchmark algorithms.