Ion track-based electronic elements

In the past years, fundaments were set for a new type of electronics which is based on tracks in insulators formed by individual or multiple swift heavy ions. Due to the possibility of inserting any (semi)conducting material into these tracks, various active and passive electronic devices can be created. Among them are also transistor-like and Esaki diode-like elements. As many of these structures have sensing properties and the capability to undergo logic decisions, autonomous intelligent sensors appear to be a favourite field for future application. The use of liquid conductors may even expand the range of applicability towards medical implants.     

STOPE‐based approach for e‐readiness assessment case studies

The STOPE‐based approach is used here for practical e‐readiness assessment case studies. The approach integrates and evaluates the various e‐readiness assessment issues, over its well‐structured domains: strategy, technology, organization, people, and environment. The case studies considered concern three Saudi organizations: a government organization, a bank, and a private sector company. The results obtained provide e‐readiness indicators that illustrate the strengths and weaknesses of each organization with regard to e‐readiness strategic development issues, information and communication technology (ICT) issues, management and organization issues, people issues, and environment issues within which the organization operates. The work shows how the approach can be practically used, and it also provides practical results that direct the organizations concerned toward enhancing their e‐readiness in response to the current trend of globalizing e‐business. Copyright © 2007 John Wiley & Sons, Ltd.     

Probiotic potential and sensory properties of coconut flan supplemented with Lactobacillus paracasei and Bifidobacterium lactis

The effect of probiotic cultures on sensory performance of coconut flan during storage at 5 °C and the viability of these micro organisms for up to 28 days were investigated. Sensory analyses of the product were performed after 7, 14 and 21 days of storage. Coconut flans were produced with no addition of cultures (T1, control), or supplemented with Bifidobacterium lactis (T2), Lactobacillus paracasei (T3) and B. lactis  +  L. paracasei (T4). Populations of L. paracasei and B. lactis as single or in co-culture remained above 7 log CFU g⁻¹ during the entire storage period. Viability of L. paracasei was higher for T3. All products were well accepted and no significant differences ( P  > 0.05) were detected between the coconut flans studied. The addition of L. paracasei and B. lactis to coconut flan resulted in its having great potential as a functional food, which has high sensory acceptability.     

Model Free Approach for Non-Isothermal Decomposition of Un-Irradiated and γ-Irradiated Silver Acetate: New Route for Synthesis of Ag(2)O Nanoparticles

Kinetic studies for the non-isothermal decomposition of unirradiated and γ-irradiated silver acetate with 10(3) kGy total γ-ray doses were carried out in air. The results showed that the decomposition proceeds in one major step in the temperature range of (180-270 °C) with the formation of Ag(2)O as solid residue. The non-isothermal data for un-irradiated and γ-irradiated silver acetate were analyzed using Flynn-Wall-Ozawa (FWO) and nonlinear Vyazovkin (VYZ) iso-conversional methods. These free models on the investigated data showed a systematic dependence of Ea on α indicating a simple decomposition process. No significant changes in the thermal decomposition behavior of silver acetate were recorded as a result of γ-irradiation. Calcinations of γ-irradiated silver acetate (CH(3)COOAg) at 200 °C for 2 hours only led to the formation of pure Ag(2)O mono-dispersed nanoparticles. X-ray diffraction, FTIR and SEM techniques were employed for characterization of the synthesized nanoparticles.     

Energy efficiency and renewable energy under extreme conditions: Case studies from Antarctica

This article showcases a range of small and large scale energy efficiency and renewable energy deployments at Antarctic research stations and field camps. Due to the cold and harsh environment, significant amounts of fuel are needed to support humans working and living in Antarctica. The purchase, transportation and storage of large amounts of fossil fuel entail significant economic costs and environmental risks and have motivated developments in energy efficiency and renewable energy deployment. Over the past three decades, improved building design, behavioral change, cogeneration, solar collectors, solar panels and wind turbines have been found to be effective in Antarctica, demonstrating that harsh environmental conditions and technological barriers do not have to limit the deployment of energy efficiency and renewable energy. The ambition to run entire stations or field camps on 100% renewable energy is increasingly common and feasible. While the power requirements of Antarctic research stations are small compared to urban installations on other continents, these case studies clearly demonstrate that if energy efficiency and renewable energy can be deployed widely on the coldest, darkest and most remote continent of the world, their deployment should be more widespread and encouraged on other continents.     

Hybrid Secure Equivalent Computing Model for Distributed Computing Applications

Wireless Personal Communications - Distributed computing applications provide concurrent processing and services executed from different systems through a common cloud platform. However, without...     

Synthesis and dielectric relaxation behavior of 55B2O3–15SiO2– 30Na2O: WO3 glass system

55 B₂O₃ – 15 SiO₂ – 30 Na₂O: x WO₃, (x ranging from 0 to 5 wt%) glass composites were prepared according to the melt-quenching procedure. The prepared samples were characterized via X-ray diffraction and broad band dielectric spectroscopy (viz., dielectric constant (ε₁), tanδ and AC conductivity (σ_AC) over a wide range of frequency and temperature). No sharp peaks were shown in the XRD pattern and is evidence of the amorphous nature of the samples. It turns out that the values of ε₁ and ε₂ are increasing at higher temperatures particularly at lower frequencies. The energy barrier height, W_M values decreased as 0.27, 0.25 and 0.22 while showed value of 0.29 eV for 5.0 wt% WO₃. In the dielectric modulus plots, two relaxation processes are found especially on the higher temperature side. It also shifted a higher frequency with increasing temperature. The values of exponent s have been found to lie between 0.48 and 0.74, which confirms that the conduction mechanism in the glass samples follows the correlated barrier hopping model. By calculating the activation energy associated with the relaxation processes and DC conductivity, it was found that the values are close, which indicates that the same charges contribute to the two processes.     

Bond graph modeling,design and experimental validation of a photovoltaic/fuel cell/ electrolyzer/battery hybrid power system

This work presents a complete bond graph modeling of a hybrid photovoltaic-fuel cell-electrolyzer-battery system. These are multi-physics models that will take into account the influence of temperature on the electrochemical parameters. A bond graph modeling of the electrical dynamics of each source will be introduced. The bond graph models were developed to highlight the multi-physics aspect describing the interaction between hydraulic, thermal, electrochemical, thermodynamic, and electrical fields. This will involve using the most generic modeling approach possible for managing the energy flows of the system while taking into account the viability of the system. Another point treated in this work is to propose. In this work, a new strategy for the power flow management of the studied system has been proposed. This strategy aims to improve the overall efficiency of the studied system by optimizing the decisions made when starting and stopping the fuel cell and the electrolyzer. It was verified that the simulation results of the proposed system, when compared to simulation results presented in the literature, that the hydrogen demand is increased by an average of 8%. The developed management algorithm allows reducing the fuel cell degradation by 87% and the electrolyzer degradation by 65%. As for the operating time of the electrolyzer, an increment of 65% was achieved, thus improving the quality of the produced hydrogen. The Fuel Cell's running time has been decreased by 59%. With the ambition to validate the models proposed and the associated commands, the development of this study gave rise to the creation of an experimental platform. Using this high-performance experimental platform, experimental tests were carried out and the results obtained are compared with those obtained by simulation under the same metrological conditions.     

Deep hybrid model-based predictive control with guarantees on domain of applicability

A hybrid model integrates a first-principles model with a data-driven model which predicts certain unknown dynamics of the process, resulting in higher accuracy than first-principles model. Additionally, a hybrid model has better extrapolation capabilities compared with a data-based model, which is useful for process control and optimization purposes. Nonetheless, the domain of applicability (DA) of a hybrid model is finite and should be taken into account when developing a hybrid model-based predictive controller in order to maximize its performance. To this end, a Control Lyapunov–Barrier Function-based model predictive controller (CLBF-based MPC) is developed which utilizes a deep hybrid model (DHM), that is, a deep neural network (DNN) combined with a first-principles model. Additionally, theoretical guarantees are provided on stability as well as on system states to stay within the DA of the DHM. The efficacy of the proposed control framework is demonstrated on a continuous stirred tank reactor.     

Developing an innovative soft computing scheme for prediction of air overpressure resulting from mine blasting using GMDH optimized by GA

Engineering with Computers - Air overpressure (AOp) is one of the most important undesirable effects induced by blasting operations in the mining or tunneling projects. Hence, the present precise...