Density Functional Theory Modeling of (001)Si–Oxynitride Interfaces

Four interface models for crystalline oxynitride on (001)Si substrates are proposed and investigated. All four models are proposed to model thin oxynitride films on Si substrates, according to experimental findings and theoretical studies on amorphous oxynitride films and nitrogenated SiO₂. State-free insulating interfaces were obtained by expanding the bulk oxynitride cell by approximately 12% and 1% along the [100] and [010] axes, respectively, and interfacing it with (001)Si. Results demonstrate state-free insulating interfaces for all models with, however, valence-band offsets slightly above or below 1 eV. The significant decrease in the valence-band offsets is mainly attributed to the significant expansion of the oxynitride’s lattice constant to lattice-matched (001)Si, as well as to the high concentration of nitrogen atoms in the oxynitride bulk.     

Noise Temperature Increase Effect on Total Outage Analysis of an Interfered Satellite Link

The ever increasing demand for bandwidth and multimedia services has led to the employment of Ka and V band in modern satellite communication networks. In these frequency bands, rain attenuation is the most dominant fading mechanism deteriorating the performance of the Earth-space links. Moreover, interference due to propagation phenomena increases the outage time of the satellite links and should be taken into account for the reliable design of a satellite communication network. In this paper, a physical propagation model for the prediction of carrier-to-noise plus interference ratio statistics of a broadband satellite link incorporating the receiver noise temperature increase due to rain, is presented The obtained numerical results highlight the significance of the latter effect and investigate the impact of various operational, geometrical and climatic parameters in the total outage analysis. Some simple mathematical formulas for the prediction of the carrier-to-noise plus interference ratio, based on the above theoretical results, are also presented.     

Application of Kluyveromyces marxianus, Lactobacillus delbrueckii ssp. bulgaricus and L. helveticus for sourdough bread making

The application of Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) as starter cultures for sourdough bread making was examined. Production of lactic and acetic acids, bread rising, volatile composition, shelf-life and organoleptic quality of the sourdough breads were evaluated. The amount of starter culture added to the flour, the dough fermentation temperature and the amount of sourdough used were examined in order to optimise the bread making process. The use of mixed cultures led to higher total titratable acidities and lactic acid concentrations compared to traditionally made breads. Highest acidity (3.41 g lactic acid/kg of bread) and highest resistance to mould spoilage were observed when bread was made using 50% sourdough containing 1% K. marxianus and 4% L. delbrueckii ssp. bulgaricus. The use of these cultures also improved the aroma of sourdough breads, as shown by sensory evaluations and as revealed by GC–MS analysis.     

Cracking of Electrolytic Tough Pitch Copper Plates During Hot Rolling

Journal of Failure Analysis and Prevention - Failure analysis is performed in electrolytic tough pitch copper plates that have been severely fractured during the initial hot rolling passes. A...     

Thermal characteristics of an air-cooled open-cathode proton exchange membrane fuel cell stack via numerical investigation

In light of stricter emissions regulations and depleting fossil fuel reserves, fuel cell vehicles (FCVs) are one of the leading alternatives for powering future vehicles. An open-cathode, air-cooled proton exchange membrane fuel cell (PEMFC) stack provides a relatively simple electric generation system for a vehicle in terms of system complexity and number of components. The temperature within a PEMFC stack is critical to its level of performance and the electrochemical efficiency. Previously created computational models to study and predict the stack temperature have been limited in their scale and the inaccurate assumption that temperature is uniform throughout. The present work details the creation of a numerical model to study the temperature distribution of an 80-cell Ballard 1020ACS stack by simulating the cooling airflow across the stack. Using computational fluid dynamics, a steady-state airflow simulation was performed using experimental data to form boundary conditions where possible. Additionally, a parametric study was performed to investigate the effect of the distance between the stack and cooling fan on stack performance. Model validation was performed against published results. The temperature distribution across the stack was identical for the central 70% of the cells, with eccentric temperatures observed at the stack extremities, while the difference between coolant and bipolar plate temperatures was approximately 10°C at the cooling channel outlets. The results of the parametric study showed that the fan-stack distance has a negligible effect on stack performance. The assumptions regarding stack temperature uniformity and measurement were challenged. Lastly, the hypothesis regarding the negligible effect of fan-stack distance on stack performance was confirmed.     

Deep Affect Prediction in-the-Wild: Aff-Wild Database and Challenge,Deep Architectures,and Beyond

International Journal of Computer Vision - Automatic understanding of human affect using visual signals is of great importance in everyday human–machine interactions. Appraising human...     

Reliable M2M/IoT data delivery from FANETs via satellite

The use of unmanned aerial vehicles (UAVs) is rising in several application fields. This work deals with the communication challenges in UAV swarms, or flying ad hoc network (FANET), when taking into account non–line‐of‐sight scenarios. The use of satellites is a necessity in such operating conditions; thus, this work provides architectural considerations and performance assessments when several (FANETs) share an uplink random access satellite channel, fed with M2M/IoT traffic generated from on‐board sensors, to be reliably delivered to a remote ground destination.     

Control Charts for Monitoring Correlated Poisson Counts with an Excessive Number of Zeros

The zero‐inflated Poisson distribution serves as an appropriate model when there is an excessive number of zeros in the data. This phenomenon frequently occurs in count data from high‐quality processes. Usually, it is assumed that these counts exhibit serial independence, while a more realistic assumption is the existence of an autocorrelation structure between them. In this work, we study control charts for monitoring correlated Poisson counts with an excessive number of zeros. Zero‐inflation in the process is captured via appropriate integer‐valued time series models. Extensive numerical results are provided regarding the performance of the considered charts in the detection of changes in the mean of the process as well as the effects of zero‐inflation on them. Finally, a real‐data practical application is given. Copyright © 2016 John Wiley & Sons, Ltd.