Particle Swarm Optimization with Parameter Dependency Walls and its sample application to the microstrip-like interconnect line design

In this paper, we first propose and formulate a novel approach in Particle Swarm Optimization (which we call “Particle Swarm Optimization with Parameter Dependency Walls”) for handling the dependencies between the design parameters. After revisiting the definition of Particle Swarm Optimization; we try to visualize the physical meaning of the concepts lying beneath our approach, and demonstrate the existence of analytical solution needed throughout the implementation. In order to illustrate a practical application of our approach, we first revisit the empirical closed-form characteristic impedance expression for the microstrip-like interconnect line with a ground plane aperture. Then, we apply our approach in order to calculate the optimized parameters of microstrip-like interconnect lines in the synthesis problem. The proposed procedure can be useful for the rapid solution of the optimization problems in which there exist dependencies between/among the input variables.     

Multicriteria decision making in energy planning using a modified fuzzy TOPSIS methodology

Energy planning is a complex issue which takes technical, economic, environmental and social attributes into account. Selection of the best energy technology requires the consideration of conflicting quantitative and qualitative evaluation criteria. When decision-makers’ judgments are under uncertainty, it is relatively difficult for them to provide exact numerical values. The fuzzy set theory is a strong tool which can deal with the uncertainty in case of subjective, incomplete, and vague information. It is easier for an energy planning expert to make an evaluation by using linguistic terms. In this paper, a modified fuzzy TOPSIS methodology is proposed for the selection of the best energy technology alternative. TOPSIS is a multicriteria decision making (MCDM) technique which determines the best alternative by calculating the distances from the positive and negative ideal solutions according to the evaluation scores of the experts. In the proposed methodology, the weights of the selection criteria are determined by fuzzy pairwise comparison matrices. The methodology is applied to an energy planning decision-making problem.     

A fully integrated,highly linear CMOS T/R switch for X‐Band phased array radars

This paper presents the design and implementation of a single‐pole, double‐throw transmit/receive (T/R) switch for X‐Band (8–12 GHz) phased array radar applications. The T/R switch was fabricated in a 0.25‐µm SiGe BiCMOS process and occupies 0.44‐mm² chip area, including pads. The design focuses on the techniques, primarily, to achieve higher power handling capability (P_1dB), along with higher isolation and better insertion loss (IL) of the T/R switch. These techniques include resistive‐body floating, using on‐chip impedance transformation networks and DC biasing of all terminals of the T/R switch. In addition, optimization of transistor widths and parallel resonance technique are used to improve IL and isolation, respectively. All these design techniques resulted in a measured IL of 3.6 dB, isolation of 34.8 dB and IP_1dB of 28.2 dBm at 10 GHz. The return losses at both input and output ports are better than 16 dB from 8 to 12 GHz. To our knowledge, this paper presents the single‐ended CMOS T/R switch with the highest IP_1dB, competitive isolation and comparable IL at X‐Band, compared to other reported works in the literature and attributed to the unique design methodologies and techniques. Copyright © 2012 John Wiley & Sons, Ltd.     

Modelling of a 5-kW wind energy conversion system with induction generator and comparison with experimental results

A 5-kW wind energy conversion system (WECS) having induction generator is designed and implemented. The induction machine is connected to the power system through PWM inverter and PWM rectifier. Two digital PI controllers are used, one of them is for regulating dc link voltage and the other is for speed control of induction machine. The whole system is governed by a single fixed point digital signal processing unit (DSP). A detailed simulation program is prepared by using Matlab facilities in order to predict the performance of the controllers before implementation.     

Load-induced transitions in the lubricity of adsorbed poly(L-lysine)-g-dextran as a function of polysaccharide chain density

Chain-density gradients of poly(l-lysine)-graft-dextran (PLL-g-dex), a synthetic comblike copolymer with a poly(l-lysine) backbone grafted with dextran side chains, were fabricated on an oxidized silicon substrate. The influence of the changing dextran chain density along the gradient on the local coefficient of friction was investigated via colloidal-probe lateral force microscopy. Both in composition and structure, PLL-g-dex shares many similarities with bottlebrush biomolecules present in natural lubricating systems, while having the advantage of being well-characterized in terms of both architecture and adsorption behavior on negatively charged oxide surfaces. The results indicate that the transition of the dextran chain density from the mushroom into the brush regime coincides with a sharp reduction in friction at low loads. Above a critical load, the friction increases by more than an order of magnitude, likely signaling a pressure-induced change in the brush conformation at the contact area and a corresponding change in the mechanism of sliding. The onset of this higher-friction regime is moved to higher loads as the chain density of the film is increased. While in the low-load (and low-friction) regime, increased chain density leads to lower friction, in the high-load (high-friction) regime, increased chain density was found to lead to higher friction.     

Particle damage and exposure analysis in HPGR crushing of selected copper ores for column leaching

In mining operations, jaw and gyratory crushers are generally used for primary crushing, and cone crushers are used for secondary crushing. During the past decade, however, high-pressure grinding rolls (HPGR) are being considered due to potential processing benefits such as energy savings, improved exposure/liberation and particle weakening. At this time there is no detailed quantification of particle damage and downstream benefits from HPGR crushing are uncertain. In the present research, copper ores (copper oxide ore and copper sulfide ore) were crushed by a jaw crusher and by HPGR and the products were evaluated for particle damage and copper grain exposure by X-ray computed tomography. Column leaching was done to determine the rate and extent of copper recovery.X-ray computed tomography analysis and laboratory column leaching experiments for copper oxide ore revealed that products from HPGR crushing have more particle damage and higher copper recoveries when compared with products of the same size class from jaw crusher crushing. Generally the copper recovery from column leaching of the oxide ore was found to be dependent on the extent of grain exposure, which increases with a decrease in particle size.In the case of the copper sulfide ore, copper recovery was found to be independent of the crushing technique despite the fact that more particle damage was observed in products from HPGR crushing. This unexpected behavior for the copper sulfide ore might be due to the high head grade and strong leach solution. Column leaching results also show that about 80–90% of the copper was recovered from the copper sulfide ore in a relatively short leaching time irrespective of crushing technique. As expected, copper recoveries improved with a decrease in the particle size of the copper sulfide ore as exposure of copper mineral grains increased.     

Chemical, microbiological and sensory changes associated with fish sauce processing

The production of sardine fermented fish sauce was replicated in the laboratory in order to study the chemical, microbiological and sensory changes associated with the process. Fish sauce were produced by incubating mixtures of sardine (Sardina pilchardus) at different concentrations of sodium chloride and glucose at 37 °C for 57 days. Changes in chemical composition (moisture, protein, fat contents), pH, total volatile basic nitrogen (TVB-N, mg N/100 g fish flesh), trimethylamine (TMA-N, mg/100 g fish flesh), thiobarbituric acid (TBA, mg malonaldehyde/kg fish flesh), water activity (aw), color measurement, total viable count, lactic acid bacteria count, yeast and moulds counts and sensory analyses were observed. The fish sauces with spices were determined lower bacteria counts than fish sauces without spices. The addition of glucose to the fish sauces caused a significant increasing in the bacterial counts. Staphylococcus aureus and yeast-mould counts were not detected during fermentation period. The use of spices in fermentation of sardine enhanced good color, aroma and taste.     

Cadmium(II)-N-Ethylimidazole Coordination Polymer via Different Coordination Environment and Chloro Bridges: Synthesis, X-ray Structure, Spectroscopic and Thermal Analysis

A novel coordination polymer [Cd₂(μ-Cl)₄(Neim)₃]_n (1) (Neim = N-ethylimidazole) was synthesized and structurally characterized by means of elemental analysis, thermal analysis, FT-IR spectrum and single-crystal X-ray diffraction. There are two different cadmium centers in 1. One of these metal centers has octahedral geometry, while the other has square pyramidal geometry. Two Neim ligands are coordinated to the Cd(II) ion in octahedral geometry while one Neim ligand is coordinated to the Cd(II) ion in square pyramidal geometry. Relatively weak C–H···Cl interactions between N-ethylimidazole molecules and chloro ions in the complex play an important role in the construction of a three-dimensional supramolecular framework. Complex 1 exhibits photoluminescence emission in solid state at room temperature.     

Micro-Capacitor Behavior of Poly(3-Hexyl Thiophene)/Carbon Fiber/Electrolyte System and Equivalent Circuit Model

In this article, 3-Hexyl thiophene (3HTh) monomer was electrocoated on carbon fiber micro electrode (CFME) to study electrochemical impedance spectroscopic (EIS) analysis. Poly(3HTh)/CFME is characterized by Cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), Scanning electron microscopy-Energy Dispersive X-ray analysis (SEM-EDX), and electrochemical impedance spectroscopy (EIS). The effects of different monomer concentrations (0.5, 1.0 and 1.5 mM) on polymer were reported in 0.1 M tetraethyl ammonium tetrafluoroborate (TEABF₄)/acetonitrile (ACN) solution. The highest low frequency capacitance (C_LF = 1.394 mF cm^?2) was obtained for [3HTh]₀ = 0.5 mM. The equivalent circuit model of R(QR(CR)(RW))(CR) was examined for polymer/electrolyte system.     

Evaluating Drying Potential of Different Sludge Types: Effect of Sludge Organic Content and Commonly Used Chemical Additives

Drying of residual treatment sludge is one of prerequisites in final disposal of this hazardous material. In this study, sludge drying potential (SDP) of different sludge types (DST) and the effect of organic content and commonly used chemical additives, including polyelectrolyte and lime, on SDP were investigated in a full-scale municipal wastewater treatment plant (WWTP). Freshly collected sludge samples were used in all experiments, which were conducted in onsite laboratory of sludge treatment facility. Studied sludge types were composed of raw biological sludge (RBS), raw primary sludge (RPS), mixed sludge (MS), dewatered sludge (DS), and limed sludge (LS). Halogen radiation was used for sludge drying. Organic content of sludge was represented by total organic carbon (TOC), dissolved organic carbon (DOC), and lost on ignition (LOI) parameters. Relations and interactions among the SDR(s) of DST(s) were statistically determined using independent samples t-test. The effect of organic content and chemicals additives on SDP was also statistically analyzed using linear regression model. Results of the study imply that each surveyed sludge type had a different SDP. Furthermore, organic composition of sludge and chemical additives had a significant impact on SDP.