A simple CMOS-based inductor simulator and frequency performance improvement techniques

In this paper, a new CMOS grounded positive tunable inductor simulator based on using two simple CMOS transconductors and an inverting amplifier is presented. The introduced inductor simulator uses a grounded capacitor; accordingly, it is suitable for integrated circuit (IC) fabrication. In addition a CMOS circuit for realizing negative tunable resistor which can be used for parasitic cancellation in inductor simulators and consequently enhancing their frequency performances is developed. A novel method for providing high-frequency performance improvement of simulated inductors is also introduced. Simulation and experimental results are given to demonstrate the performance of the developed inductor simulator and validity of the proposed frequency performance improvement method.     

The use of thyme and laurel essential oil treatments to extend the shelf life of bluefish (Pomatomus saltatrix) during storage in ice

The objective of this investigation was to study the effect of thyme and laurel essential oil treatments on the quality of bluefish during storage in ice for 13?days. The quality of bluefish during storage time was evaluated by sensory, chemical, physical, physicochemical and microbiological analysis. According to the sensory evaluation results, shelf life of control and treated bluefish samples stored in ice were 9 and 11?days, respectively. Total volatile base nitrogen and trimethylamine values gave acceptable results for up to 9?days for the control groups samples and 13?days for treated groups. Free fatty acid, peroxide and thiobarbituric acid values for treated samples were lower than the control. Microbial growth during storage in ice for control samples was higher than treated samples. The results obtained from this study showed that the shelf life of stored bluefish in ice has extended by 3?C4?days compare to the control samples.     

A long-term view of worldwide fossil fuel prices

This paper reviews a long-term trend of worldwide fossil fuel prices in the future by introducing a new method to forecast oil, natural gas and coal prices. The first section of this study analyses the global fossil fuel market and the historical trend of real and nominal fossil fuel prices from 1950 to 2008. Historical fossil fuel price analysis shows that coal prices are decreasing, while natural gas prices are increasing. The second section reviews previously available price modelling techniques and proposes a new comprehensive version of the long-term trend reverting jump and dip diffusion model. The third section uses the new model to forecast fossil fuel prices in nominal and real terms from 2009 to 2018. The new model follows the extrapolation of the historical sinusoidal trend of nominal and real fossil fuel prices. The historical trends show an increase in nominal/real oil and natural gas prices plus nominal coal prices, as well as a decrease in real coal prices. Furthermore, the new model forecasts that oil, natural gas and coal will stay in jump for the next couple of years and after that they will revert back to the long-term trend until 2018.     

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.