Wind energy potential at Kano airport via weibull parameters

A clean, source free and environmentally friendly alternate source of energy such as wind energy can be use for providing sustainable power supply to remedied an epileptic and unreliable power supply systems. This paper carried out an analysis of wind speed data at Mallam Aminu Kano International Airport in Nigeria using Weibull distribution methods to determine the wind features and its potentials necessary for power supply generation. Weibull parameter methods have been chosen for this analysis because of its efficiency. A six years (2009-2014) monthly mean wind speed data measured at 10 m height was collected and extrapolated to 100 m height level for statistical analysis. The average wind speed, standard deviation, Weibull scale and shape parameters has been analyzed for both 10 m and 100 m height levels. The minimum average wind speed was found to be 5m/s and the maximum average wind speed was 12.5 m/s at the 10 m height level, the Weibull scale parameters were found generally higher than the shape parameters. The Weibull parameter models were validated by RMSE. The site has been found to have great potentials for utility power generation capacity

A cuckoo search optimization scheme for non-convex economic load dispatch

This paper presents a Cuckoo Search (CS) based algorithm to solve constrained economic load dispatch (ELD) problems. The proposed methodology easily deals with non-smoothness of cost function arising due to the use of valve point effects. The performance of the algorithm has been tested on systems possessing 13 and 40 generating units involving varying degrees of complexity. The findings affirm that the method outperforms the existing techniques, and can be a promising alternative approach for solving the ELD problems in practical power system

Chaos-Enhanced Cuckoo Search for Economic Dispatch with Valve Point Effects

Economic dispatch determines the optimal generation outputs to minimize the toal fuel cost while satisfying the load demand and operational constraints. Modern optimization techniques fail to solve the problem in a robust manner and finding robust global optimization techniques is necessary for efficient system operation. In this study, the potentiality of introducing chaos into the standard Cuckoo Search (CS) in order to further enhance its global search ability is investigated. Deterministic chaotic maps are random-based techniques that can provide a balanced exploration and exploitation searches for the algorithm. Four different variants are generated by carefully choosing four different locations (within the standard CS) with potential adoption of a candidate chaotic map.Then detailed studies are carried out on benchmark power system problems with four different locations to find out the most efficient one. The best of all test cases generated is chosen and compared with algorithms presented in the literature. The results show that the proposed method with the proposed chaotic map outperforms standard CS. Additionally, the chaos-enhanced CS has a very good performance in comparison with QPSO and NSS

Can Van Hove singularities be observed in relativistic heavy-ion collisions ?

Based on general arguments the in-medium quark propagator in a quark-gluon plasma leads to a quark dispersion relation consisting of two branches, of which one exhibits a minimum at some finite momentum. This results in a vanishing group velocity for collective quark modes. Important quantities such as the production rate of low mass lepton pairs and mesonic correlators depend inversely on this group velocity. Therefore these quantities, which follow from self energy diagrams containing a quark loop, are strongly affected by Van Hove singularities (peaks and gaps). If these sharp structures could be observed in relativistic heavy-ion collisions it would reveal the physical picture of the QGP as a gas of quasiparticles.Comment: 12 pages including nine figures and style files, invited talk given at the ICPAQGP-2001, November 26-30, 2001, Jaipur, Indi

Bound - states for truncated Coulomb potentials

The pseudoperturbative shifted - $l$ expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge

Influence of temperature and relative humidity on the efficacy of diatomaceous earth and Metarhizium anisopliae (Metschinkoff) Sorokin (Hyphomycetes: Deuteromycotina) against Tyrophagus fatimii F. (Astigmata: Acaridae)

The combined as well as the alone effect of diatomaceous earth (DE) and entomopathogenic fungi were evaluated against Tyrophagus fatimii (Astigmata: Acaridae). Two different dose rates of DE (1 g and 1.5 g/kg of wheat) and three of the fungus Metarhizium anisopliae (Hyphomycetes: Deuteromycotina) (3.6 x 107, 3.6 x 108 and 3.6 x 109 conidia/kg of wheat) were taken and studied at 20°C and 25°C with 45% and 55% r.h. under three exposure intervals. It was found that the combined effect of DE diatomaceous earth and M. anisopliae was maximum at 25°C and 55% r.h. which gave 75% adult mortality at their highest dose rates, however, DE alone exhibited the highest mortality (61.3%) at 25°C and 45% r.h. On the other hand, M. anisopliae gave maximum mortality of mites (48.7%) at 20°C and 55% r.h. at 3.6 x 109 conidia/kg of wheat. It was concluded that the efficacy of both DE and M. anisopliae increased with the increase of the exposure interval. Moreover, the increase of dose increased the mortality. In addition, temperature and r.h. are the key factors for determining the effectiveness of both DE and M. anisopliae. Keywords: Diatomaceous earth, Tyrophagus fatimii, Metarhizium anisopliae, Stored wheat

Wavelet-based short-term load forecasting using optimized anfis

This paper focuses on forecasting electric load consumption using optimized Adaptive Neuro-Fuzzy inference System (ANFIS). It employs the use of Particle Swarm Optimization (PSO) to optimize ANFIS, with aim of improving its speed and accuracy. It determines the minimum error from the ANFIS error function and thus propagates it to the premise part. Wavelet transform was used to decompose the input variables using Daubechies 2 (db2). The purpose is to reduce outliers as small as possible in the forecasting data. The data was decomposed in to one approximation coefficients and three details coefficients. The combined Wavelet-PSO-ANFIS model was tested using weather and load data of Nova Scotia province. It was found that the model can perform more than Genetic Algorithm (GA) optimized ANFIS and traditional ANFIS, which is been optimized by Gradient Decent (GD). Mean Absolute Percentage Error (MAPE) was used to measure the accuracy of the model. The model gives lower MAPE than the other two models, and is faster in terms of speed of convergence

Unidirectional Invisibility and PT-Symmetry with Graphene

We investigate the reflectionlessness and invisibility properties in the transverse electric (TE) mode solution of a linear homogeneous optical system which comprises the $\mathcal{PT}$-symmetric structures covered by graphene sheets. We derive analytic expressions, indicate roles of each parameter governing optical system with graphene and justify that optimal conditions of these parameters give rise to broadband and wide angle invisibility. Presence of graphene turns out to shift the invisible wavelength range and to reduce the required gain amount considerably, based on its chemical potential and temperature. We substantiate that our results yield broadband reflectionless and invisible configurations for realistic materials of small refractive indices, usually around $\eta = 1$, and of small thickness sizes with graphene sheets of rather small temperatures and chemical potentials. Finally, we demonstrate that pure $\mathcal{PT}$-symmetric graphene yields invisibility at small temperatures and chemical potentials.Comment: 20 pages, 1 table 17 figure

Dirac eigenvalues for a softcore Coulomb potential in d dimensions

A single fermion is bound by a softcore central Coulomb potential V(r) = -v/(r^q + b^q)^(1/q), v>0, b>0, q \ge 1, in d>1 spatial dimensions. Envelope theory is used to construct analytic lower bounds for the discrete Dirac energy spectrum. The results are compared to accurate eigenvalues obtained numerically.Comment: 8 pages 1 figur