An Efficient Hybrid Approach to Solve Bi-objective Multi-area Dynamic Economic Emission Dispatch Problem

Abstract

Single period economic dispatch cannot handle the intertemporal constraints in multi-period environment. To cope with this issue, the extension of economic dispatch over multiple time intervals (i.e., dynamic economic dispatch) has been introduced that considers the intertemporal constraints between different time intervals. Another issue is determining the most economical generation dispatch that could supply the area demand without violating the tie-line capacity, which cannot be solved by conventional economic dispatch problems. However, this study shows that the most economic schedule of power generation cannot satisfy echo-system expectation; therefore, making a compromise between fuel cost and environmental issues, a hot-button subject in industrialized nations, seems to be crucial. To reach the goals a bi-objective multi-area dynamic economic dispatch approach, which can handle intertemporal and multi-area constraints concurrently, is proposed to assist power system operators more and more. Finally, a hybrid algorithm, namely gray wolf optimizer-particle swarm optimization is introduced to solve the proposed problem and also a set of benchmark problems. By implementing the proposed approach on two small (10-unit, three areas) and large (40-unit, four areas) scale test systems, about 3.1% and 3.3% improvement in generation cost is obtained, respectively compare to the best reported results in the literature.     

Probiotic yoghurt functionalised with microalgae and Zedo gum: chemical,microbiological, rheological and sensory characteristics

In this study, using a central composite design, the effects of addition of Spirulina platensis and Zedo gum to plain and probiotic yoghurt samples were investigated during storage. Lactobacillus paracasei proliferation was directly dependent on the addition of microalgae and was inversely affected by storage time. Probiotic samples containing S. platensis showed the highest antioxidative activity. Maximum stability was obtained at higher amounts of Zedo gum, while organoleptic and rheological attributes improved at 0.25% Zedo gum. Given the importance of probiotic viability, supplementation of probiotic yoghurt with Zedo gum/S. platensis may be consideredas a novel nutraceutical formulation.     

Synthesis of copolymers of a linoleic acid derivative and properties of the copolymer films

Addition copolymers of maleic anhydride and a commercially available conjugated fatty acid, Pamolyn 380, were synthesized via thermal initiation. The copolymers had moderately high molecular weights and were obtained in reasonable yields. The copolymers were characterized by nuclear magnetic resonance and infrared spectroscopy and by elemental analysis. Based on this analytical data and examples from the literature, the copolymers were assigned regularly alternating chain morphology. Coatings were formulated with the copolymers, and films over a metal substrate were evaluated. The films were found to have excellent solvent resistance, high hardness, and good gloss. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 261–267, 2001     

Special all-round fillet weld for anchor rods of base-plate T-stub connections

The eccentricity between connected steel parts and the anchor rods in base-plate T-stub connections makes base plates the weaker components in tension and compression. Additionally, the oversized holes in base plates lead to irregular placement of anchor rods, resulting in an unsymmetrical shear behavior. Thus, this paper aims to develop a special all-round fillet weld to connect the anchor rods beneath the base plate concentrically to the steel part, removing the base plate from the load-transferring chain. Accordingly, design criteria were first developed based on Eurocode's directional method considering all the potential failure modes. Next, results were validated by conducting experimental work. The digital image correlation technique (DIC) was also used to capture the strain distribution developed over the tested specimen till failure. Consequently, numerical analysis was carried out to investigate the fracture strength and the fracture angle and compare the special fillet weld with its equivalent standard one, which has the same weld volume. The results indicated that the proposed design criteria produced safe strength prediction for the developed special all-round fillet weld. Furthermore, the results revealed that using a special all-round fillet weld instead of the equivalent standard one can increase the strength by about 8% and improve the ductility of the weld. However, it decreases the stiffness of the weld by about 21%. The fracture surface occurred at $15°$ from the face of the anchor rod, which produced a higher strength than the predicted tensile strength calculated according to the theoretical throat plane.     

Forming Limit Diagram Prediction of Tailor-Welded Blank Using Experimental and Numerical Methods

The forming limit diagram (FLD) is a useful method for characterizing the formability of sheet metals. In this article, different numerical models were used to investigate the FLD of tailor-welded blank (TWB). TWBs were CO₂ laser-welded samples of interstitial-free (IF) steel sheets with difference in thickness. The results of the numerical models were compared with the experimental FLD as well as with the empirical model proposed by the North American Deep Drawing Research Group. The emphasis of this investigation is to determine the performance of these different approaches in predicting the FLD. These numerical models for FLD are: second derivative of thinning (SDT), effective strain rate (ESR), major strain rate (MSR), thickness strain rate (TSR), and thickness gradient (TG). Results of this research show necking will be happened, when the value of MSR, TSR, ESR criteria is maximum, TG????0.78 and SDT criterion has the first peak in forming process time. The value of dome height of TWB samples at failure was predicted based on the numerical models for samples with different widths. These numerical predictions were compared with the experimental results. The SDT model indicates a better agreement with experimental results in prediction of both the FLD and the limit dome height (LDH) in comparison to the other numerical models. Both numerical and experimental results show that minimum of LDH is happened in plane strain condition.     

Integrated all-optical infrared switchable plasmonic quantum cascade laser

We report a type of infrared switchable plasmonic quantum cascade laser, in which far field light in the midwave infrared (MWIR, 6.1 μm) is modulated by a near field interaction of light in the telecommunications wavelength (1.55 μm). To achieve this all-optical switch, we used cross-polarized bowtie antennas and a centrally located germanium nanoslab. The bowtie antenna squeezes the short wavelength light into the gap region, where the germanium is placed. The perturbation of refractive index of the germanium due to the free carrier absorption produced by short wavelength light changes the optical response of the antenna and the entire laser intensity at 6.1 μm significantly. This device shows a viable method to modulate the far field of a laser through a near field interaction.     

A discrete multicomponent droplet evaporation model; effects of O2-enrichment,steam injection,and EGR on evaporation of diesel droplet

A discrete multicomponent (DMC) model for droplet evaporation in convective ambient is developed. Three different sets of correlations for Nusselt and Sherwood number are examined. The model is compared with experimental data for single and multicomponent droplet evaporation at different conditions and the most suitable set of correlations is selected. Having validated model, the diesel droplet evaporation under different ambient conditions and compositions is investigated. Increasing of oxygen mass fraction in N₂–O₂ mixture ambient from 0 to 1 first decreases and then increases the lifetime. Steam addition enhances the evaporation rate and it affects evaporation more significantly at higher temperatures. Exhaust gas recirculation (EGR) results in slight variations in droplet lifetime and its heating period.     

New SRAM design using body bias technique for low‐power and high‐speed applications

In this paper, a new SRAM cell with body‐bias actively controlled by a control circuit and word line is introduced to realize low‐power and high‐speed applications. The cell uses two word lines, which vary between positive and negative voltage levels to control the body bias of cell's transistors. In this design, using a peripheral control circuit with the least possible number of transistors, the access time is decreased and also a trade‐off between static and dynamic power consumption is provided. Compared to a conventional SRAM cell, the proposed cell reduces the static power consumption by 82% and improves the read performance by 40% and the write performance by 27%. Copyright © 2013 John Wiley & Sons, Ltd.     

Investigating the possibility of Sonofusion in Deuterated acetone

In this article, energetic implosion of a single vapor bubble induced by a standing acoustic wave is theoretically studied and the Sonoluminescing bubble parameters involved in Sonofusion in Deuterated acetone (C₃D₆O) are investigated. Parameters such as radius, wall velocity, interior temperature and pressure of the bubble influenced by various driving pressure amplitudes in Deuterated acetone at ∼0 °C are investigated. Based on the obtained results, the possibility of thermonuclear fusion inside imploding cavitation bubbles is discussed. The interior pressure of C₃D₆O vapor bubbles at the collapse time is extremely high and the increase of the pressure amplitude increases the pressure inside the bubble. Our findings reveal that the maximum temperature inside acoustic-induced cavitation bubble in Deuterated acetone increases with the acoustic pressure amplitude and it is much higher than the maximum temperature inside acoustic induced cavitation bubbles in liquids such as water and acids. Consequently, the calculated temperature at the pressure amplitude of 7.23 bar was about 3.7 × 10⁵ K and it is predicted that at the reported experimental condition, the case of a bubble cluster subjected to the pressure amplitude of about 15 bar, the temperature inside the bubble reaches to 1.2 × 10⁶ K.     

Organic geochemical characteristics of Middle to Late Eocene Shahbazan Formation in Dezful Embayment,SW Iran: A case study from Qaleh-Nar oilfield

Abstract

In a first attempt, Middle to Late Eocene Shahbazan Formation as a possible source rock in Dezful Embayment was geochemically investigated. Maturity indicators derived from Rock-Eval pyrolysis (T_max and PI) and gas chromatography (CPI) show that the organic matter, which dominated by a mixed type II/III kerogen, is thermally mature and has already entered the oil window. A fair to good petroleum-generative potential is suggested by moderate to relatively high values of total organic carbon (TOC) and potential yield (S₁+S₂). Deposition of Shahbazan Formation under low-oxygen condition, which is represented by low pristane/phytane ratio (<1), conduced to preservation of organic matter. This is in accordance with considerable TOC contents, ranging from 1.01 to 1.72?wt%. The relation between pristane/nC₁₇ and phytane/nC₁₈ as well as terrigenous/aquatic ratio (～1) represent the mixed marine and terrestrially sourced organic matter. Based on the results obtained from this study, Shahbazan Formation could have been acted as a prolific oil and gas source rock.