Objective Site Characterization Using Clustering of Piezocone Data

Cluster analysis is a statistical method for grouping similar mathematical data sets and is used herein for delineating geostratigraphy from piezocone penetration test data. In terms of site characterization, clustering is an improvement over other statistical methods because no preliminary estimation of the inherent groups within the analyzed data is needed, and no overlapping is permitted between identified clusters. Clustering can accommodate single or multivariables and no data filtering is required. Its application to defining stratigraphic interfaces is illustrated using five case studies with layered profiles. Clustering is able to detect major changes within the stratigraphy not apparent by visually examining the trends of piezocone data or by available cone soil classification methods.     

Effect of mutation schemes on convergence to optimum design of steel frames

In this paper an attempt is made to modify a distributed genetic algorithm (DGA) to minimize the weight of steel frames. The main aspects of modifications include the twin analogy and a number of mutation schemes. Although the mutation is a secondary operator in the GA, it plays an influential role in diversifying the population and exploring more feasible design space. In this research, four different mutation schemes are examined and their effects on convergence to optimum solutions are evaluated. Using three benchmark examples, it is demonstrated that mutation operator can efficiently influence on the speed of convergence and consequently saving computation time. As coding a program is required, the DO-DGA software has been developed to handle the algorithm. DO-DGA applies modified DGA, including different mutation schemes, to obtain the global optimum solution.     

Is technological change biased toward energy? A multi-sectoral analysis for the French economy

Since the adoption and implementation of new technologies has an important influence on the structure and performance of the economy in both developed and developing countries, many research papers are devoted to the technology–economy nexus. Motivated by the fact that the impact of technical progress on the demand for different production factors may vary depending on the bias of the technological change, in this paper, by estimating a translog cost-share system and using state-space modeling technique, we investigate to what extent the direction of technical change is biased toward energy and away from other factors. By applying this methodology to the French economy for the period 1978–2006 the obtained results suggest that: first, technical change has a non-neutral impact on factor demands; second, capital-saving technical progress is present in the majority of the sectors studied; third, energy demand has increased in all sectors but electricity and gas. These findings may have important policy implications for environmental and energy issues in France.     

Iron oxide (n-Fe2O3) nanowire films and carbon modified (CM)-n-Fe2O3 thin films for hydrogen production by photosplitting of water

Iron oxide n-Fe₂O₃ nanowire photoelectrodes were synthesized by thermal oxidation of Fe metal sheet (Alfa Co. 0.25 mm thick) in an electric oven then tested for their photoactivity. The photoresponse of the n-Fe₂O₃ nanowires was evaluated by measuring the rate of water splitting reaction to hydrogen and oxygen, which is proportional to photocurrent density, J_p. The optimized electric oven-made n-Fe₂O₃ nanowire photoelectrodes showed photocurrent densities of 1.46 mA cm⁻² at measured potential of 0.1 V/SCE at illumination intensity of 100 mW cm⁻² from a Solar simulator with a global AM 1.5 filter. For the optimized carbon modified (CM)-n-TiO₂ synthesized by thermal flame oxidation the photocurrent density for water splitting was found to increase by two fold to 3.0 mA cm⁻² measured at the same measured potential and the illumination intensity. The carbon modified (CM)-n-Fe₂O₃ electrode showed a shift of the open circuit potential by −100 mV/SCE compared to undoped n-Fe₂O₃ nanowires. A maximum photoconversion efficiency of 2.3% at applied potential of 0.5 V/E_aoc was found for CM-n-Fe₂O₃ compared to 1.69% for n-Fe₂O₃ nanowires at higher applied potential of 0.7 V/E_aoc. These CM-n- Fe₂O₃ and n- Fe₂O₃ nanowires thin films were characterized using photocurrent density measurements under monochromatic light illumination, UV-Vis spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Development of a simulation model for a three-dimensional wind velocity field using Ténès Algeria as a case study

A mathematical simulation model was developed that can determine the three-dimensional wind velocity field over a complex terrain. The Ténès area in the Valley of Cheliff in Algeria was used as a case study. This region is exposed to south-west circulation that makes it favorable to the use of wind energy. Knowledge of wind fields is crucial for predicting the dispersion of pollutants, for forecasting meteorological weather, for fire spread prediction and in the design and implementation of wind turbines. By means of a mass consistent model, an in-house program was developed to calculate the three-dimensional wind velocity field in the study region. The model was supported by a numerical box in which flow through is allowed for in the upper and lateral boundaries. The bottom boundary through which no flow through occurs was determined by the topographic relief at the surface. From measured wind velocities, observed values were calculated by interpolation-extrapolation. Using an optimization method, the adjusted velocities were obtained from constraints, observed velocities and the continuity equation. The model was verified with wind point data, the relative error did not exceed 6%.     

Enhancement of glass-ceramic performance by TiO2 doping: In vitro cell viability,proliferation, and differentiation

A new TiO₂-containing bioactive glass and glass-ceramics based on 50SiO₂-(45-X)CaO-(XTiO₂)-5P₂O₅ system was designed using a sol–gel technique (where X = 5, 7.5 and 10 wt %). The roles of the crystallization behavior and physicochemical characteristics of the designed glass and glass-ceramics which were played in the introduction of TiO₂ substitutions were investigated. Moreover, cell proliferation and differentiation were evaluated against human osteosarcoma cells (Saos-2). The TiO₂/CaO replacements led to the formation of a stronger glass structure and thus increased thermal parameters and the chemical stabilization of the designed materials. The FTIR data confirmed the existence of Ti within the glass and glass-ceramics samples, and no remarkable effect on their chemical integrity was observed. The XRD patterns indicated that calcium-containing minerals, including Ca₂SiO₄,Ca₃(PO₄)₂, Ca(Ti,Si)O₅, CaTiSiO₅, and Ca₁₅(PO₄)₂·(SiO₄)₆ phases were developed as a role of structure/texture under the applied heat-treatment. The results of the cytotoxicity test proved that a safe sample dose is 12–50 μg/ml, at which cell viability is ≥ 85%. The cell differentiation determined by ALP test proved the superiority of glass-ceramics compared with their native glasses. Therefore, the obtained materials could be safely used as novel biocompatible materials for the regeneration of bone tissue.     

The Impact of PbF2-Based Glasses on Radiation Shielding and Mechanical Concepts: An Extensive Theoretical and Monte Carlo Simulation Study

Journal of Inorganic and Organometallic Polymers and Materials - This work aimed to investigate the impact of Lead-fluoride based glasses via theoretical and simulation techniques on mechanical and...     

Electro-osmotic flow of fractional second-grade fluid with fractional Cattaneo heat flux through a vertical microchannel

This study investigates the unsteady electro-osmotic flow (EOF) of a fractional second-grade fluid through a vertical microchannel with convection heat transfer. The fractional Cattaneo heat flux model will be used to modify the heat equation. The solutions for the velocity and the temperature have been derived by employing the Laplace and finite Fourier sine transforms and their numerical inverses. The results show that at the beginning of the time period, the fractional parameter postpones the movement of the fluid. Furthermore, the results show that at the high values of retardation time (non-Newtonian case), the required time for the velocity and the flow rate to reach the steady state increases. Moreover, the heat relaxation time reduces the heat transfer until a critical time, and then the effect reverses.     

Safety Watchdog for universally safe gaseous high pressure hydrogen fillings

The fast filling time for hydrogen fuel cell vehicles makes them a user-friendly zero emission alternative to fossil fuel powered vehicles. The filling, by compressing gas into the vehicle tanks, produces heat that can be damaging. There are different protocols, standardized or the intellectual property of station operators, dedicated for different specific applications taking into account the specificity of the vessel and customer requirements. Standard protocols are developed for worst case conditions across a broad range of vehicle tank sizes and configurations. These worst case conditions do not result in the most economical equipment solution for hydrogen fueling. To ensure safety for different existing and future potential protocols a new “Safety Watchdog” approach is suggested in the current paper. This “Safety Watchdog” monitors the fueling process boundary conditions independently from the main process controls. The decoupling between the watchdog and the protocol allows use of protocols that are more economically beneficial while ensuring full safety conditions. The current paper provides a mathematical formulation of the Safety Watchdog as well as its validation versus modeling and field experimental data.     

Enhancing the rheological,technological, textural and microstructural characteristics of set yoghurt using certain nano-stabilisers

The purpose of this study was to investigate the impact of adding nano-stabilisers on some properties of yoghurt. Carboxymethyl cellulose (CMC), sodium alginate (SA) and kappa-carrageenan (K-C) were used at 0.2%, 0.2% and 0.02% in their original forms and 0.15%, 0.15% and 0.015% in nano-form, respectively. The effects of these additives on yoghurt pH, titratable acidity, viscosity, syneresis, texture, colour, starter culture bacterial count, mould and yeast count, coagulation time and microstructure were studied. The use of nano-stabilisers increased viscosity, hardness and coagulation time; reduced syneresis and Streptococcus thermophilus count; and improved colour. Results indicated that nano-stabilisers improved the rheological and technological characteristics of yoghurt.