A mobile renewable house using PV/wind/fuel cell hybrid power system

A photovoltaic/wind/fuel cell hybrid power system for stand-alone applications is proposed and demonstrated with a mobile house. This concept shows that different renewable sources can be used simultaneously to power off-grid applications. The presented mobile house can produce sufficient power to cover the peak load. Photovoltaic and wind energy are used as primary sources and a fuel cell as backup power for the system. The power budgeting of the system is designed based on the local data of solar radiation and wind availability. Further research will focus on the development of the data acquisition system and the implementation of automatic controls for power management.     

A new algorithm for stope boundary optimization

Stopes can be simply defined as an underground opening from which ore has been excavated.Selection of the best combination of available stope boundary will directly affect the profitability of the operation.While a few attempts has been initiated to generate the optimum stope boundary for underground mining, they fail to guarantee a true optimality in three-dimension block models.This paper proposed a new methodology which can find optimum stope layout for a given resource model in three-dimensions.The p...     

A review of Turkish natural gas distribution market

In Turkey, natural gas consumption started at 0.5 bcm (billion cubic meters) in 1987 and reached approximately 35 bcm in 2007. Turkish natural gas usage is projected to further increase remarkably in coming years. In 2001, a reform process was started to create and strengthen a competitive natural gas market. However, the reform has not worked out as expected so far. The present article discusses the application of auctions in Turkish natural gas distribution zones. After presenting a short summary of current literature, natural gas utilization and recent developments in Turkish natural gas market, we draw attention to our main focus, namely city natural gas tenders. Having described the tenders, we present problems associated with them. In the end, we touch upon some regulatory issues and provide some suggestions for improvement.     

An ordinal optimization based method for power distribution system control

This work presents an Ordinal Optimization Theory based method for power distribution system control. The solution procedure bases on an evolutionary search scheme. The method aims at minimizing the total power losses on network feeders while keeping the node voltages at near rated values against changing loading conditions. By relaxing the definition of optimality and softening the goal of optimization, ordinal optimization makes the problem easier as well as the solution process faster. A solution can be defined as good enough in performance value if it is one of the best m-percent solutions on the search space with probability P%. A solution can be defined as good enough also if its performance value approximates to the optimal value to a pre-defined extent. This work estimates the performance value, the total power loss, of the optimum state of power distribution network at a given loading condition. Then, with the two relaxed definitions for optimality, it finds the optimal settings of on-load tap changers and capacitors in a 24-h time frame. Results verify our method is proper for on-line and off-line operation.     

Solubility properties of barley flour,protein isolates and hydrolysates

Protein solubility properties of barley flours (BF), barley protein isolates (BPI) and barley protein hydrolysates (BPH) were determined as a function of pH and NaCI concentration. BPIs were produced from both hulled (BPI-1 and BPI-3) and hull-less (BPI-2 and BPI-4) barley flours. Sodium metabisulphite (BPI-1 and BPI-2) or L-cysteine (BPI-3 and BPI-4) were included in the extraction procedure. BPI-4 was hydrolyzed with Alcalase in order to produce hydrolysates of 3% (BPH-1) and 6% (BPH-2) degree of hydrolysis. Electrophoretic properties of BFs, BPIs and BPHs were examined by SDS-PAGE. The results showed that solubility properties were affected by the changes of pH and ionic strength of the medium in all samples. The solubility properties of barley proteins were especially higher in the strong acidic and basic pH regions. Solubilities of BPI-1 and BPI-2 in distilled water were lower than those of BPI-3 and BPI-4. The lowest solubility was observed around the isoelectric points of BFs and BPIs. SDS-PAGE provided significant information about the monitoring of limited protein hydrolysis that produced large quantities of low molecular weight barley protein fragments with the Alcalase treatment. The solubility properties of BPHs around the isoelectric point were increased as a result of the limited hydrolysis.     

A new continuous high‐gain controller scheme for a class of uncertain nonlinear systems

In this study, we present a new robust continuous controller mechanism for the tracking problem of uncertain nonlinear systems. The proposed strategy is based on a Lyapunov‐type stability argument and only requires the uncertainties of the dynamical system to be the first‐order differentiable to achieve asymptotic practical tracking. For the ease of presentation, the controller formulation is presented on a general, second‐order dynamical system, extension to higher order versions are also possible with a considerably small effort. Simulation studies comparing the performance of the proposed method with the classical Sliding mode and robust integral of the sign of the error controller are presented to illustrate the performance and the feasibility of the proposed strategy. Experimental validation on a two link direct drive robot manipulator are also included to illustrate the implementability of the proposed method. Copyright © 2013 John Wiley & Sons, Ltd.     

Generation of bi-monotone patches from quadrilateral mesh for reverse engineering

Thanks to recent improvements, computational methods can now be used to convert triangular meshes into quadrilateral meshes so that the quadrilateral elements capture well the principal curvature directional fields of surfaces and intrinsically have surface parametric values. In this study, a quadrilateral mesh generated using the mixed integer quadrangulation technique of Bommes et al. is used for input. We first segment a quadrilateral mesh into four-sided patches. The feature curves inside these patches are then detected and are constrained to act as the patch boundaries. Finally, the patch configuration is improved to generate large patches. The proposed method produces bi-monotone patches, which are appropriate for use in reverse engineering to capture the surface details of an object. A shape control parameter that can be adjusted by the user during the patch generation process is also provided to support the creation of patches with good bi-monotone shapes. This study mainly targets shape models of mechanical parts consisting of major smooth surfaces with feature curves between them.