Enhancement of thermochemical hydrogen production using an iron–silica magnetically stabilized porous structure

A synthesis process for creating an iron-based magnetically stabilized porous structure is described in detail. The structure is used as the reactive substrate for a two-step water splitting, hydrogen production process. The stability and reactivity of a 205 g magnetically stabilized structure operating at 873, 973, 1023 and 1073 K over eleven consecutive oxidation and reduction cycles has been investigated. Applying an external magnetic field exploits sintering and controls the geometry of the matrix of particles inside the structure in a favorable manner so that the chemical reactivity of the structure remains intact. The experimental results demonstrate that this structure yields peak hydrogen production rates of approximately 29 cm³/(min  g_Fe) at 1073 K without noticeable degradation over eleven consecutive cycles. The hydrogen production rate is considerably higher than those reported in the open literature for two-step water splitting processes. SEM images, hydrogen production rates, permeability of the bed, and the bed height confirm that the gas–solid contact area and porosity of the magnetically stabilized porous structure is sustained after consecutive cycling at high reaction temperatures.     

Engineering design complexity: an investigation of methods and measures

In this paper, two measures are proposed for valuation of size and coupling complexities of design products as abstracted by three distinct representations. The proposed size complexity measure is based on the information theoretic definition of complexity that connects the complexity of a design to the level of entropy, or uncertainty, inherent in the design product. The proposed coupling complexity measure evaluates the decomposability of the graph-based representation of design products. To validate the proposed measures, an experiment is conducted to calculate the complexities of three consumer products based on three product representations, namely, function structure, connectivity graph, and parametric associativity graph. The findings indicate that coupling and size are independent measures of a product’s complexity. Thus, it is recommended that both measures should be used. Further, the complexity of a product is not independent of the choice of representation model used to describe the product. This suggests that the complexity of a product will vary with the selected view. Finally, it is shown that the two approaches for measuring complexity of a product are generalizable and can be applied to different representations.     

Large-eddy simulation of a dispersed particle-laden turbulent round jet

The numerical results obtained by large-eddy simulation (LES) of a particle-laden axisymmetric turbulent jet are compared with the available experimental data. The results indicate that with a new stochastic subgrid-scale (SGS) closure, the effects of the particles on the carrier gas and those of the carrier gas on the particles are correctly captured by the LES. Additional numerical experiments are conducted and used to investigate the effects of particle size, mass-loading ratio, and other flow/particle parameters on the statistics of both the carrier gas phase and the particle dispersed phase.     

Micro‐modeling of porous composite anodes for solid oxide fuel cells

A new anode micromodel for solid oxide fuel cells to predict the electrochemical performance of hydrocarbon‐fuelled porous composite anodes with various microstructures is developed. In this model, the random packing sphere method is used to estimate the anode microstructural properties, and the complex interdependency among the multicomponent mass transport, electron and ion transports, and electrochemical and chemical reactions is taken into account. As a case study, a porous Ni–YSZ composite anode operated with biogas fuel is simulated numerically and distributions of the current density, polarization, and mole fraction and rate of flux of the fuel components along the thickness of the anode are determined. The effect of the anode microstructural variables including the porosity, thickness, particle‐size ratio, and particle size and volume fraction of Ni particles on the anode electrochemical performance is also studied. © 2011 American Institute of Chemical Engineers AIChE J, 58: 1893–1906, 2012     

Generalized Model of Blood Flow in a Vertical Tube with Suspension of Gold Nanomaterials: Applications in the Cancer Therapy

Gold metallic nanoparticles are generally used within a lab as a tracer, to uncover on the presence of specific proteins or DNA in a sample, as well as for the recognition of various antibiotics. They are bio companionable and have properties to carry thermal energy to tumor cells by utilizing different clinical approaches. As the cancer cells are very smaller so for the infiltration, the properly sized nanoparticles have been injected in the blood. For this reason, gold nanoparticles are very effective. Keeping in mind the above applications, in the present work a generalized model of blood flow containing gold nanoparticles is considered in this work. The blood motion is considered in a cylindrical tube under the oscillating pressure gradient and magnetic field. The problem formulation is done using two types of fractional approaches namely CF (Caputo Fabrizio) and AB (Atangana-Baleanue) derivatives, whereas blood is considered as a counter-example of Casson fluid. Exact solutions of the problem are obtained using joint Laplace and Hankel transforms, and a comparative analysis is made between CF and AB. Results are computed in tables and shown in various plots for embedded parameters and discussed. It is found that adding 0.04-unit gold nanoparticles to blood, increase its heat transfer rate by 4 percent compared to regular blood. It is also noted that the heat transfer can be enhanced in the blood with memory.1     

Quality enhancement of AZO thin films at various thicknesses by introducing ITO buffer layer

Due to the simultaneously superior optical transmittance and low electrical resistivity, transparent conductive electrodes play a significant role in semiconductor electronics. To enhance the electrical properties of these films, one approach is thickness increment which degrades the optical properties. However, a preferred way to optimize both electrical and optical properties of these layers is to introduce a buffer layer. In this work, the effects of buffer layer and film thickness on the structural, electrical, optical and morphological properties of AZO thin films are investigated. Al-doped zinc oxide (AZO) is prepared at various thicknesses of 100 to 300 nm on the bare and 100 nm-thick indium tin oxide (ITO) coated glass substrates by radio frequency sputtering. Results demonstrate that by introducing ITO as a buffer layer, the average values of sheet resistance and strain within the film are decreased (about 76 and 3.3 times lower than films deposited on bare glasses), respectively. Furthermore, the average transmittance of ITO/AZO bilayer is improved nearly 10% regarding single AZO thin film. This indicates that bilayer thin films show better physical properties rather than conventional monolayer thin films. As the AZO film thickness increases, the interplanar spacing, d₍₀₀₂₎, strain within the film and compressive stress of the film in the hexagonal lattice, decreases indicating the higher yield of AZO crystal. Moreover, with the growth in film thickness, carrier concentration and optical band gap (E_g) of AZO film are increased from 4.62?×?10¹⁹ to 8.21?×?10¹⁹ cm^?3 and from 3.55 to 3.62 eV, respectively due to the Burstein-Moss (BM) effect. The refractive index of AZO thin film is obtained in the range of 2.24–2.26. With the presence of ITO buffer layer, the AZO thin film exhibits a resistivity as low as 6?×?10^?4 Ω cm, a sheet resistance of 15 Ω/sq and a high figure of merit (FOM) of 1.19?×?10⁴ (Ω cm)^?1 at a film thickness of 300 nm. As a result, the quality of AZO thin films deposited on ITO buffer layer is found to be superior regarding those grown on a bare glass substrate. This study has been performed over these two substrates because of their significant usage in the organic light emitting diodes and photovoltaic applications as an enhanced carrier injecting electrodes.     

Investigating the effect of filler types on thermodynamic parameters and their relationship with moisture sensitivity of asphalt mixes

Filler plays a significant role in mastic cohesion and adhesion between aggregate–asphalt binder in asphalt mixes. In the majority of research on investigating moisture damage based on thermodynamic concepts, little attention has been given to the role of filler. In the present study, 20 different combinations of asphalt mixes made with 4 filler types (stone powder, hydrated lime, calcium carbonate and portland cement), with two types of asphalt binder (60–70 and 85–100), and two types of aggregate (limestone and granite) were used. Then thermodynamic parameters (with and without considering the effect of filler) were calculated and the relationship between these parameters and test results of moisture sensitivity of asphalt mixes was investigated using statistical analyses. Results obtained by thermodynamic parameters show that only stone powder filler caused an increase in free energy of adhesion between base asphalt binder and aggregates, and other fillers reduced free energy of adhesion. The maximum amount of debonding energy in samples made by asphalt binder 60–70, was related to mastics containing calcium carbonate and hydrated lime fillers, and in asphalt binder 85–100, mastics containing portland cement and calcium carbonate had the maximum amount of debonding energy. However, the minimum amount of debonding energy was related to the mastic containing stone powder. In addition, the results of moisture sensitivity mechanical tests show that samples containing calcium carbonate and hydrated lime fillers had the maximum amount of tensile strength ratio. Finally, the amount of adjusted coefficient of correlation between debonding energy and modified Lottman test results increased from 0.553 in 4 base compounds (without filler) to 0.701 in 16 compounds with filler. The difference in correlation coefficients show the necessity to use the effect of filler on calculating thermodynamic parameters in investigating moisture sensitivity of various asphalt mixes.     

Rich document representation and classification: An analysis

There are three factors involved in text classification. These are classification model, similarity measure and document representation model. In this paper, we will focus on document representation and demonstrate that the choice of document representation has a profound impact on the quality of the classifier. In our experiments, we have used the centroid-based text classifier, which is a simple and robust text classification scheme. We will compare four different types of document representations: N-grams, Single terms, phrases and RDR which is a logic-based document representation. The N-gram representation is a string-based representation with no linguistic processing. The Single term approach is based on words with minimum linguistic processing. The phrase approach is based on linguistically formed phrases and single words. The RDR is based on linguistic processing and representing documents as a set of logical predicates. We have experimented with many text collections and we have obtained similar results. Here, we base our arguments on experiments conducted on Reuters-21578. We show that RDR, the more complex representation, produces more effective classifier on Reuters-21578, followed by the phrase approach.     

Configuration and dynamic reconfiguration of components using the coordination paradigm

One of the most promising approaches in developing component-based (possibly distributed) systems is that of coordination models and languages. Coordination programming enjoys a number of advantages such as the ability to express different software architectures and abstract interaction protocols, support for multi-linguality, reusability and programming-in-the-large, etc. Configuration programming is another promising approach in developing large scale, component-based systems, with the increasing need for supporting the dynamic evolution of components. In this paper we explore and exploit the relationship between the notions of coordination and (dynamic) configuration and we illustrate the potential of control- or event-driven coordination languages to be used as languages for expressing dynamically reconfigurable software architectures. We argue that control-driven coordination has similar goals and aims with the notion of dynamic configuration and we illustrate how the former can achieve the functionality required by the latter.     

Digital manufacturing market: a semantic web-based framework for agile supply chain deployment

Manufacturing Market is a market in which manufacturing process capacity is the object of trade. In a market, units of capacity, represented as manufacturing services, can be acquired as needed and when needed, thus making supply chains more responsive to fluctuations in supply and demand. Although Manufacturing Market can be built physically as a spot market, its benefits can be better realized in a web-based framework. We refer to the web-based version of Manufacturing Market as Digital Manufacturing Market (DMM). The major challenges in deployment of a virtual market for manufacturing services include standard representation of manufacturing needs and capabilities, incorporation of intelligent supplier search and evaluation mechanism, and automation of supply chain configuration process. This paper introduces DMM through its major components including a multi-agent framework, a formal ontology for representation of manufacturing services as well as a matchmaking methodology used for connecting buyers and sellers of manufacturing services based on their semantic similarities. The ultimate goal of the proposed framework is to enable autonomous deployment of manufacturing supply chains based on the specific technological requirements defined by particular work orders.