An improved bacterial foraging algorithm for combined static/dynamic environmental economic dispatch

Economic dispatch is carried out at the energy control center to find out the optimal output of thermal generating units such that power balance criterion is met, unit operating limits are satisfied and the fuel cost is minimized. With growing environmental awareness and strict government regulations throughout the world, it has become essential to optimize not only the total fuel cost but also the harmful emissions, both, under static as well as dynamic conditions. The static environment economic dispatch finds the optimal output of generating units for a fixed load demand at a given time, while the dynamic environmental economic dispatch schedules the output of online generators with changing power demands over a certain time period (normally one day) so as to minimize these two conflicting objectives, simultaneously. In this paper, the price penalty factor approach is employed for simultaneous minimization of cost and emission. The generator ramp rate constraints, non-convex and discontinuous nature of cost function and the large number of generators in practical power plants, make this problem very difficult to solve. Here, a fuzzy ranking approach is employed to identify the solution which offers the best compromise between cost and emission objectives.     

Transfer efficiency for airless painting systems

Spray transfer efficiency (TE) is defined as the mass fraction of sprayed paint which is deposited on the intended target, the remainder of the sprayed paint becomes undesirable overspray. The relationship between TE and gun supply pressure (or paint mass flow rate), gun-to-target distance, gun traverse speed, the angle of the spray gun relative to the target (gun-to-target angle), plus spray cone angle is reported herein for a typical fan spray system. Experimental results indicate that spray momentum rate (SMR) and droplet size dictate the TE for the various combinations of parameters considered here. The key finding is that TE correlates with SMR and spray mean drop size (Sauter mean diameter, or D₃₂) via an expression of the form TE=a+b SMR − c (SMR)²+d D₃₂, where a, b, c, and d are coefficients, determined by fitting the experimental data, and SMR is estimated via SMR=m²/ρA, where the paint mass flow rate m, the paint density is ρ, and the gun exit orifice effective tip cross sectional area is A. This expression accounts for physical phenomena that govern sprayed droplet deposition characteristics, such as entrainment, bounce-back, and drop size. Experimental results also show that, for the range of parameters studied, gun traverse speed has no effect on TE, but increasing the angle of the spray gun relative to the target (gun-to-target angle), increasing the spray cone angle, or increasing the gun-to-target distance will decrease TE.     

Topology optimization for nonlinear dynamic problems: Considerations for automotive crashworthiness

Crashworthiness of automotive structures is most often engineered after an optimal topology has been arrived at using other design considerations. This study is an attempt to incorporate crashworthiness requirements upfront in the topology synthesis process using a mathematically consistent framework. It proposes the use of equivalent linear systems from the nonlinear dynamic simulation in conjunction with a discrete-material topology optimizer. Velocity and acceleration constraints are consistently incorporated in the optimization set-up. Issues specific to crash problems due to the explicit solution methodology employed, nature of the boundary conditions imposed on the structure, etc. are discussed and possible resolutions are proposed. A demonstration of the methodology on two-dimensional problems that address some of the structural requirements and the types of loading typical of frontal and side impact is provided in order to show that this methodology has the potential for topology synthesis incorporating crashworthiness requirements.     

Rapid Assessment Testing of Polymer Aluminum Electrolytic Capacitors in Elevated Temperature–Humidity Environments

Aluminum electrolytic capacitors with polymer electrolytes were developed to obtain lower equivalent series resistance (ESR) than that is achievable with liquid electrolytes. Replacement of the liquid electrolyte with a solid conductive polymer also overcomes the propensity of the liquid to evaporate over time, which leads to a reduction in capacitance and an increase in ESR values. However, capacitor manufacturers acknowledge that humidity can degrade the polymer, thereby having an adverse effect on the reliability of polymer aluminum (PA) capacitors. In the current study, surface mount and thru-hole PA capacitors from two different manufacturers were subjected to highly accelerated stress testing (110 °C, 85% RH) and elevated temperature–humidity (85 °C, 85% RH) conditions for rapid assessment. The polymer electrolyte in the capacitors was poly(3,4-ethylenedioxythiophene). Failure analysis was performed to determine the observed failure modes and the underlying failure mechanisms. The dominant failure modes observed were an increase in leakage current and an increase in ESR.     

Cooperative Impulse Radio Ultra-Wideband Communication Using Coherent and Non-Coherent Detectors: A Review

Ultra-wideband (UWB) is a booming technology in the field of wireless communication. This paper presents a brief idea related to the various coherent and non-coherent IR-UWB detectors. Due to the limitation in transmit power spectral density of UWB system, the major challenges faced by UWB system includes, achieving Quality of Service, system performance and coverage area. So, the combination of UWB system with cooperative communication will not only improve the system performance, but also help in expanding coverage area of signals. A brief review of the work done by various researchers in the field of cooperative impulse radio (IR) UWB communication is also presented in this paper. The working principle and performance analysis of the various coherent and non-coherent IR-UWB detectors using cooperative relay strategies are also discussed at large in this paper. The various fixed cooperative relay strategies used for cooperative UWB communication is Amplify and Forward, Decode and Forward and Detect and Forward. From the simulation results it can be inferred that, even though IR-UWB DTR receiver gives a much better BER performance than IR-UWB ED receiver using both cooperative and non-cooperative strategies, yet ED receiver is preferred because of its less complexity and low power consumption. Future prospects in the field of cooperative IR-UWB communication have also been discussed in this paper.     

Molecular typing tools for identifying and characterizing lactic acid bacteria: a review

Food Science and Biotechnology - Identification and classification of beneficial microbes is of the highest significance in food science and related industries. Conventional phenotypic approaches...     

Multi-mode hydrogen storage in nanocontainers

Hydrogen can be stored in containers or in materials (in molecular or atomic forms). The atomic form can further exist as multiple phases. Molecular hydrogen can be adsorbed on the surface or can be present inside the material. By invoking multiple modes of hydrogen storage, we establish a paradigm shift in the philosophy of hydrogen storage. Using a novel strategy of storage of molecular hydrogen in metal (Pd) nanocontainers, we observe that 18% hydrogen is in molecular form. Interestingly, this is achieved at 25 °C and 1 atm pressure; which is in contrast to storage in MOFs and carbonaceous materials like nanotubes. Enhancement in storage capacity as compared to Pd nanocrystals of the same mass is observed (36% increase at 1 atm & 25 °C), along with fast kinetics (0.5 wt% hydrogen absorption in 5 s). A new mechanism for hydrogen storage involving the dual catalytic role of Pd is established.     

Analysis of Leuconostoc citreum strains using multilocus sequence typing

Food Science and Biotechnology - The objective of this study was to perform genetic diversity analysis of 13 strains isolated from South Korean foods by multilocus sequence typing (MLST). For...     

Blade‐resolved simulations of a model wind turbine: effect of temporal convergence

Simulations of a model wind turbine at various tip‐speed‐ratios were carried out using Tenasi, a node‐centered, finite volume unstructured flow solver. The simulations included the tunnel walls, tower, nacelle, hub and the blades. The effect of temporal convergence on the predicted thrust and power coefficients is evaluated and guidelines for best practices are established. The results presented here are for tip‐speed‐ratios of 3, 6 and 10, with 6 being the design point. All simulations were carried out at a freestream velocity of 10 m s^?1 with an incoming boundary layer present and the wind turbine RPM was varied to achieve the desired tip‐speed‐ratio. The performance of three turbulence models is evaluated. The models include a one‐equation model (Spalart–Allmaras), a two‐equation model (Menter SST) and the DES version of the Menter SST. Turbine performance as well as wake data at various locations is compared to experiment. All the turbulence models performed well in terms of predicting power and thrust coefficients. The DES model was significantly better than the other two turbulence models for predicting the mean and fluctuating components of the velocity in the wake. Copyright © 2015 John Wiley & Sons, Ltd.     

Comparison study of chitosan,EDTA, eugenol and peppermint oil for antioxidant and antimicrobial potentials in chicken noodles and their effect on colour and oxidative stability at ambient temperature storage

The aim of this study was to investigate the antioxidant and antimicrobial activity of chitosan, EDTA, eugenol and peppermint essential oil and their effect on color and oxidative stability of chicken noodles stored at 35 ± 2 °C. Results indicated that among the four preservatives, eugenol treatment exhibited higher ABTS⁺ (2-2-azinobis-3ethylbenthiazoline-6-sulphonic acid) radical cation activity (89.54%), DPPH (1, 1-diphenyl-2-picrylhydrazil) (51.30%) and superoxide anion scavenging activity (66.82%). Total polyphenol content was also higher in eugenol treated samples. The samples treated with eugenol and chitosan protect against an increase lightness (L-value) and decrease in redness (a) and yellowness (b) values during storage. However, pH value was highest in noodles with chitosan treatment while TBARS (2-thiobarbituric acid reacting substances) and FFA (Free fatty acids) contents were lowest in noodles with eugenol irrespective of storage periods. Eugenol treatment also showed positive impact on microbiological quality and sensory attributes. In conclusion, eugenol has more potential as a natural preservative to increase shelf-life of chicken noodles.