Correction to: Deposition of bismuth sulfide and aluminum doped bismuth sulfide thin films for photovoltaic applications

Journal of Materials Science: Materials in Electronics -     

Investigation of factors affecting dynamic modulus and phase angle of various asphalt concrete mixtures

This study investigated the dynamic response of various asphalt concrete (AC) mixtures subjected to sinusoidal loading. Eight AC mixtures (four wearing and four base course) were selected including (but not limited to): superpave, asphalt institute manual series, and dense bituminous macadam. The uniaxial dynamic modulus (|E*|) test at various temperatures (4.4–54.4 °C) and frequencies (0.1–25 Hz) was conducted using asphalt mixture performance tester. Statistical analysis of two-level factorial was employed to regulate the factors affecting the AC mixtures. The results revealed that an increase in temperature (from 21.1 to 37.8 °C), translated into 45 and 43 % drop in |E*| values on average while 80 and 67 % decrease in |E*| values was attributed to the sweep of frequency (from 25 to 0.1 Hz) for wearing and base course mixes, respectively. Non-linear regression model was developed to express the dynamic modulus as a function of test temperature, loading frequency and mixture volumetric parameter. Furthermore, Witczak model of dynamic modulus prediction was evaluated and the results indicated a close fit with an average under prediction error of 0.20. The study characterized and ranked the representative AC mixtures that could help in selecting the material/gradation for mechanistic-empirical pavement design approach.     

An efficient Dynamic Addressing based routing protocol for Underwater Wireless Sensor Networks

Underwater Wireless Sensor Networks (UWSNs) are different in many aspects as compared to terrestrial sensor networks. Other than long propagation delays and high error probability, continuous node movement makes it hard to manage the location information of sensor nodes. Determining the location of every node is a major issue as nodes can move continuously with the water currents. In order to handle the problem of large propagation delays and unreliable link quality, many algorithms have been proposed and some of them provide good solutions for these issues, but continuous node movements still need attention. In order to handle the problem of node mobility, we proposed a Hop-by-Hop Dynamic Addressing Based (H2-DAB) routing protocol, where every node in the network will be assigned a routable address in a quick and efficient way without requiring an explicit configuration or any dimensional location information. It helps to provide an option where nodes can communicate without any centralized infrastructure, also a mechanism is available where nodes can come and leave the network without having any serious effect on the rest of the network. Simulation results show that H2-DAB can manage easily during the quick routing changes where node movements are very frequent yet require little or no overhead in order to complete its tasks.     

Stress enhanced TiO2 nanowire growth on Ti–6Al–4V particles by thermal oxidation

Titanium dioxide (TiO₂) nanowires were grown on Ti - 6wt% Al - 4wt% V (Ti64) particles by thermal oxidation. To investigate the effect of stress on nanowire growth, the particles were milled in a planetary ball mill prior to the thermal oxidation. Thermal oxidation of the Ti64 particles was carried out in a horizontal tube furnace in a controlled oxygen atmosphere in the temperature range of 700–900 °C. The oxygen concentration was varied from 20 ppm to 80 ppm in Ar atmosphere. Nanostructures were characterized by high resolution field emission scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. TiO₂ nanowires grew on the surface of Ti64 particles and exhibited a square/rectangular cross sectional shape with thicknesses of 20–40 nm and lengths of 2–3 μm. Residual stress was found to play a significant role in nanowire growth. This was confirmed by growing TiO₂ nanowires on Ti64 alloy sheet with an induced stress gradient along its length. An improvement in nanowire coverage was observed in regions of high residual stress. A stress-induced growth mechanism is suggested to explain the confinement of nanowire growth to one dimension during thermal oxidation.     

Backstepping and Synergetic Controllers for the Chemotherapy of Brain Tumor

International Journal of Control, Automation and Systems - The treatment of brain tumors by chemotherapy through the controlled rate of drug has been a challenging task since long. Two nonlinear...     

Joining and mechanical testing of oxide/oxide (Nextel ™610/alumina-zirconia) ceramic composites

Efficient joining materials and techniques are of critical importance for the integration of CMCs in high performance structures. Continuous oxide fiber Nextel^? 610/alumina-zirconia composites were successfully joined to themselves by using a novel glass-ceramic based on the SiO₂-CaO-Al₂O₃-MgO-Y₂O₃-ZrO₂ system.Crystallization kinetic of the novel glass-ceramic was studied using Matusita, Sakka and Ozawa equations. Single lap off-set shear tests and four-point bending tests were performed at room temperature and at 850 °C to investigate the mechanical strength of the joints. Thermal ageing was performed at 850 °C for 100 h in air to check the thermal stability of the joined components. The results showed that the joints were oxidation resistant and the joined interfaces were well bonded. Single lap off-set shear tests on joined samples resulted in delamination of the composites. The average flexural strengths of the joined samples were 71 MPa and 81 MPa, at room temperature and at 850 °C, respectively.     

Difference kernel iterative method for linear and nonlinear partial differential equations

The purpose of this paper was to propose a new method to solve partial differential equations arising in the field of science and engineering. In this new method, we have reduced the multiple integrals into a single integral and expressed it in terms of a difference kernel. To make the calculation easy and convenient, we have used the Laplace transformation to solve the difference kernel. The method is very simple, easy to understand and calculation minimizing as compared to the Adomian decomposition method and the variational iteration method. Some examples are given to verify the reliability and efficiency of the method.     

基于无线信道指纹的室内位置感应系统分析(英文)

This paper reviews and analyses various simplified-RFID (Radio Frequency Identification) indoor location systems, and proposes an improved implementation based on the propagation channel "fingerprinting" principle. The focus of the design aims to provide accurate location estimation, while minimising infrastructural requirements. The proposed approach is based on the LANDMARC (Indoor Location Sensing Using Active RFID) with Virtual Reference tags (VIRE) and implemented with dynamic linear interpolation and ...