Nanocoating of montmorillonite/Mg-β-tricalcium phosphate on orthodontic titanium miniscrews

Mini-implants (1-2 mm in diameter) are miniscrews that are placed in the jaw bones to help Orthodontists move teeth in a controlled manner. The reasons behind their increasing popularity over the past decade is that mini-implants are easily placed and removed under local anaesthetic and can withstand up to 300g force. Unfortunately, their high rate of failure (10-30%) poses a problem to clinicians and their patients alike. Advances in the field of nanotechnology presented a wide range of solutions to biological problems. We developed a nanocoating of nanoclay reinforced magnesium substituted β-TCP on titanium surface to enhance the stability of orthodontic miniscrews. ©2010 IEEE.published_or_final_versionThe 3rd IEEE International NanoElectronics Conference (INEC), Hong Kong, 3-8 January 2010. In Proceedings of 3rd INEC, 2010, p. 817-81

Accounting for variation in designing greenhouse experiments with special reference to greenhouses containing plants on conveyor systems

Extent: 21p.Background: There are a number of unresolved issues in the design of experiments in greenhouses. They include whether statistical designs should be used and, if so, which designs should be used. Also, are there thigmomorphogenic or other effects arising from the movement of plants on conveyor belts within a greenhouse? A two-phase, single-line wheat experiment involving four tactics was conducted in a conventional greenhouse and a fully-automated phenotyping greenhouse (Smarthouse) to investigate these issues. Results and discussion: Analyses of our experiment show that there was a small east–west trend in total area of the plants in the Smarthouse. Analyses of the data from three multiline experiments reveal a large north–south trend. In the single-line experiment, there was no evidence of differences between trios of lanes, nor of movement effects. Swapping plant positions during the trial was found to decrease the east–west trend, but at the cost of increased error variance. The movement of plants in a north–south direction, through a shaded area for an equal amount of time, nullified the north–south trend. An investigation of alternative experimental designs for equally-replicated experiments revealed that generally designs with smaller blocks performed best, but that (nearly) trend-free designs can be effective when blocks are larger. Conclusions: To account for variation in microclimate in a greenhouse, using statistical design and analysis is better than rearranging the position of plants during the experiment. For the relocation of plants to be successful requires that plants spend an equal amount of time in each microclimate, preferably during comparable growth stages. Even then, there is no evidence that this will be any more precise than statistical design and analysis of the experiment, and the risk is that it will not be successful at all. As for statistical design and analysis, it is best to use either (i) smaller blocks, (ii) (nearly) trend-free arrangement of treatments with a linear trend term included in the analysis, or, as a last resort, (iii) blocks of several complete rows with trend terms in the analysis. Also, we recommend that the greenhouse arrangement parallel that in the Smarthouse, but with randomization where appropriate.Chris J Brien, Bettina Berger, Huwaida Rabie and Mark Teste

Integrating GIS and Hydrology for Flood Risk Analysis

Spatial analysis using GIS was evaluated for its ability to predict the potential hazard of a flood event in the Illinois River region in the State of Illinois. The data employed in the analysis are available to the public from trusted organizations such as Illinois State Geological Survey (ISGS), and the US Geological Survey (USGS). The purposes of this study are to 1) examine the applicability of GIS spatial analysis to determine flood inundation risk, and 2) to determine how to do so with the least amount of data possible, while still producing an accurate flood inundation risk map. This study concentrates on areas that have stream gauge data with definable flood stage(s) and utilizes the Inverse Distance Weighted (IDW) spatial analysis interpolation method on different digital elevation models (DEM) with different resolutions to determine the potential flood level over the study area. Resulting maps created for the Illinois River region yielded about 80% agreement to the actual effects of the Illinois River flood near Peoria on April 23rd, 2013. As a result, it was concluded that it is possible to create a decent flood prediction map using only two initial input data layers: stream gauges, and a digital elevation model (DEM)

On the performance of DF-based power-line/visible-light communication systems

This paper presents a comprehensive performance analysis of an integrated indoor power line communication (PLC)/visible light communication (VLC) system with the presence of a decode-and-forward (DF) relay. The existing indoor power line networks are used as the backbone for VLCs. The performance of the proposed system is evaluated in terms of the average capacity and the outage probability. A new unified mathematical method is developed for the PLC/VLC system and analytical expressions for the aforementioned performance metrics are derived. Monte Carlo simulations are provided throughout the paper to verify the correctness of the analysis. The results reveal that the performance of the proposed system deteriorates with increasing the end-to-end distance and improves with increasing the relay transmit power. It is also shown that the outage probability of the system under consideration is negatively affected by the vertical distance to user plane

Channel modeling for overhead line equipment for train communication

The demand for high-speed data access to railway infrastructure and internet broadband data in railway is increasing due to the high density of the trains and passengers. Currently, communication access in trains is based on radio frequency (RF) wireless access networks that are slow and insufficient for the demands of the high-speed railway (HSR) and its customers. However, performance, service attributes, frequency band, and industrial support should be considered for the selection of a suitable communication system that can fulfill the requirements of HSR operation. This paper investigates overhead line equipment (OLE) as access network connecting trains to the backbone communication networks. The ABCD transmission model is used to represent the transfer function of the OLE channel. It was shown that transmission over OLE is affected by the frequency and link distance. The simulation results also show that the channel gain of the OLE channel attenuated faster at higher speeds compared to train movement at lower speeds

Performance analysis of cooperative and non-cooperative relaying over VLC channels

The line-of-sight (LoS) channel is one of the requirements for efficient data transmission in visible-light communications (VLC), but this cannot always be guaranteed in indoor applications for a variety of reasons, such as moving objects and the layout of rooms. The relay-assisted VLC system is one of the techniques that can be used to address this issue and ensures seamless connectivity. This paper investigates the performance of half-duplex (HD) conventional DF relay system and cooperative systems (i.e., selective DF (SDF) and incremental DF (IDF)) over VLC channels in terms of outage probability and energy consumption. Analytical expressions for both outage probability and the minimum energy-per-bit performance of the aforementioned relaying systems are derived. Furthermore, Monte Carlo simulations are provided throughout the paper to validate the derived expressions. The results show that exploiting SDF and IDF relaying schemes can achieve approximately 25% and 15% outage probability enhancement compared to single-hop and DF protocols, respectively. The results also demonstrate that the performance of the single-hop VLC system deteriorates when the end-to-end distances become larger. For example, when the vertical distance is 3.5m, the single-hop approach consumes 20%, 40% and 45% more energy in comparison to the DF, SDF, and IDF approaches, respectively

Enhanced Amplify-and-Forward Relaying in Non-Gaussian PLC Networks

Relaying over power line communication (PLC) channels has the potential to improve the reliability and robustness of many PLC-based applications. In particular, this paper proposes to enhance the energy efficiency (EE) of a dual-hop relaying PLC system in the presence of impulsive noise by considering energy-harvesting (EH) at the relaying modem. Amplify-and-forward (AF) relaying and time-switching relaying EH protocols are deployed in this paper. The PLC modems are assumed to have the capability to go on low-power consumption sleep mode when they are neither transmitting nor receiving. The system performance is evaluated in terms of EE and average outage probability for which analytical expressions are derived. Using the derived expressions, several system parameters are investigated, such as the channel gain, which is related to the number of network branches, EH time factor and impulsive noise characteristics. Particularly, the optimization problem of the EH time is addressed thoroughly in order to maximize the achievable gains. Results reveal that the proposed system can offer considerable improvements compared with the conventional AF relaying scheme

Improving energy efficiency in dual-hop cooperative PLC relaying systems

© 2016 IEEE. Energy efficiency (EE) in multi-hop cooperative communication systems, both wireless and wired, is increasingly becoming more and more critical. This has recently been extended to include power line communications (PLC). In this respect, we propose in this paper to enhance the EE of a dual-hop amplify-And-forward (AF) cooperative relaying PLC system by considering energy-harvesting (EH) at the relay node. The energy harvester exploits the high noisy PLC channel feature as well as the transmitted signal power to forward the source information. In light of this, we derive an analytical expression for the EE and verify it with Monte Carlo simulations. The performance of the conventional relaying system, i.e. without any EH, is also considered to clearly quantify the achievable gains. The results show that the proposed system can considerably improve the EE of PLC systems and that increasing the channel variance will always make the proposed system more energy-efficient

Outage probability analysis of WPT systems with multiple-antenna access point

© 2016 IEEE. This paper analyzes the performance of a multiple-antenna access point (AP) system with an energy-constrained single-antenna destination node in various Bernoulli-Gaussian impulsive noise environments. More specifically, we deploy the harvest-then-transmit protocol where communication is accomplished over two distinct phases: i) power transfer phase (downlink), ii) information transmission phase (up-link). In this respect, an analytical expression for the ergodic outage probability is derived and validated with Monte Carlo simulations. Results have shown that increasing the source transmit power or/and the number of AP antennas will minimize the ergodic outage probability. It is also presented that careful selection of the energy harvesting time is important to enhance the system performance

Impulsive Noise Modeling and Cancellation Strategies Over Power Line Channels

Impulsive noise is one of the main impairments over power line channels. In this respect, this paper presents the available impulsive noise models and then reviews and compare several existing mitigation techniques proposed in the literature. These methods include multicarrier modulation, nonlinear preprocessors, multiple-input multiple-output, coding and iterative techniques. Interesting comparisons between these techniques and meaningful insights are presented and discussed