Synthesis and Characterization of Novel μ-Carbonato Tetranuclear Copper Complexes [(Pip)4nCu4X4(CO3)2] in Aprotic Media

In this work, novel oxidative coupling complexes, [(Pip)4nCu4X4(CO3)2] (n = 1 or 2, X = Cl or Br, Pip = piperidine), are synthesized from the reaction of well characterized Lewis base [(Pip)4nCu4X4O2] with carbon dioxide as a Lewis acid in CH2Cl2. These carbonato-derivatives are isolated as stable solids. They are easily soluble in aprotic solvents as CH2Cl2or phNO2. Cryoscopic measurements support tetranuclear structure for all of them. Electronic spectra in the near infrared with high molecular absorptivity may be explained for tetranuclear cuban structure to fulfil 3 halo-ligands for each copper centre in [(Pip)4nCu4X4(CO3)2]. The EPR spectra for [(Pip)4nCu4X4(CO3)2] complexes are axial type of spectra (dx2-y2 G.S) suggesting elongated tetragonal distortion for all of them. Cyclic voltammograms for [(Pip)4nCu4X4(CO3)2] are irreversible in character. These tetranuclear carbonato complexes show catalytical activity. They initiate the oxidation of 2,6-dimethylphenol (DMP) to 3,3’,5,5’-tetramethyl-4,4’-diphenoquinone (DPQ).

Kinetics of Oxidation of 2,6-Dimethylphenol (DMP) Using Novel μ-Carbonato [(Pip)4nCu4X4(CO3)2] Complexes

This paper reports the kinetics of the oxidation of 2,6-dimethylphenol (DMP) to get 3,3’,5,5’-tetra- methyl-4,4’-diphenoquinone (DPQ) using novel oxidative coupling complexes [(Pip)4nCu4X4-(CO3)2] (n = 1 or 2, X = Cl or Br, Pip = piperidine). The new prepared tetranuclear complexes were characterized using cryoscopic measurements, electronic spectra, FTIR, EPR and cyclic voltammetry techniques. These complexes are catalytically active. The proposed mechanism of the catalytic oxidative coupling can be illustrated as a pre-equilibrium, K, between the catalyst and DMP to form a complex intermediate which is converted to activated complex through the rate determining step, k2, to form the final product. The inverse of the observed rate constants kobsd versus 1/[DMP]2 gives a straight line with intercept. From the slope and the intercept, both K and k2 are obtained. At different temperatures, thermodynamic and kinetic parameters are evaluated. It is worth to mention that, the dependence of kobsd on [DMP]2 indicates that the coordination number for every copper center in both n = 1 or 2 in [(Pip)4nCu4X4(CO3)2] is equal to six. Therefore, carbonato bridging centers in n = 1 acts as a tridentate ligand, while for n = 2 acts as a bidentate ligand.

Identity Verification of Individuals Based on Retinal Features Using Gabor Filters and SVM

Authentication reliability of individuals is a demanding service and growing in many areas, not only in the military barracks or police services but also in applications of community and civilian, such as financial transactions. In this paper, we propose a human verification method depends on extraction a set of retinal features points. Each set of feature points is representing landmarks in the tree of retinal vessel. Extraction and matching of the pattern based on Gabor filters and SVM are described. The validity of the proposed method is verified with experimental results obtained on three different commonly available databases, namely STARE, DRIVE and VARIA. We note that the proposed retinal verification method gives 92.6%, 100% and 98.2% recognition rates for the previous databases, respectively. Furthermore, for the authentication task, the proposed method gives a moderate accuracy of retinal vessel images from these databases.

The Cost Functional and Its Gradient in Optimal Boundary Control Problem for Parabolic Systems

The problems of optimal control (OCPs) related to PDEs are a very active area of research. These problems deal with the processes of mechanical engineering, heat aeronautics, physics, hydro and gas dynamics, the physics of plasma and other real life problems. In this paper, we deal with a class of the constrained OCP for parabolic systems. It is converted to new unconstrained OCP by adding a penalty function to the cost functional. The existence solution of the considering system of parabolic optimal control problem (POCP) is introduced. In this way, the uniqueness theorem for the solving POCP is introduced. Therefore, a theorem for the sufficient differentiability conditions has been proved.

Estimations of Weibull-Geometric Distribution under Progressive Type II Censoring Samples

This paper deals with the Bayesian inferences of unknown parameters of the progressively Type II censored Weibull-geometric (WG) distribution. The Bayes estimators cannot be obtained in explicit forms of the unknown parameters under a squared error loss function. The approximate Bayes estimators will be computed using the idea of Markov Chain Monte Carlo (MCMC) method to generate from the posterior distributions. Also the point estimation and confidence intervals based on maximum likelihood and bootstrap technique are also proposed. The approximate Bayes estimators will be obtained under the assumptions of informative and non-informative priors are compared with the maximum likelihood estimators. A numerical example is provided to illustrate the proposed estimation methods here. Maximum likelihood, bootstrap and the different Bayes estimates are compared via a Monte Carlo Simulation

Algorithms of Confidence Intervals of WG Distribution Based on Progressive Type-II Censoring Samples

The purpose of this article offers different algorithms of Weibull Geometric (WG) distribution estimation depending on the progressive Type II censoring samples plan, spatially the joint confidence intervals for the parameters. The approximate joint confidence intervals for the parameters, the approximate confidence regions and percentile bootstrap intervals of confidence are discussed, and several Markov chain Monte Carlo (MCMC) techniques are also presented. The parts of mean square error (MSEs) and credible intervals lengths, the estimators of Bayes depend on non-informative implement more effective than the maximum likelihood estimates (MLEs) and bootstrap. Comparing the models, the MSEs, average confidence interval lengths of the MLEs, and Bayes estimators for parameters are less significant for censored models.

Numerical Investigation of the Geometric Phase and Entropy Squeezing for a Two-Level System in the Presence of Decoherence Terms

In this paper, we have presented the numerical investigation of the geometric phase and field entropy squeezing for a two-level system interacting with coherent field under decoherence effect during the time evolution. The effects of the initial state setting and atomic dissipation damping parameter on the evolution of the geometric phase and entropy squeezing have been examined. We have reported some new results related to the periodicity and regularity of geometric phase and entropy squeezing.

Study of Similarity Measures with Linear Discriminant Analysis for Face Recognition

Face recognition systems have been in the active research in the area of image processing for quite a long time. Evaluating the face recognition system was carried out with various types of algorithms used for extracting the features, their classification and matching. Similarity measure or distance measure is also an important factor in assessing the quality of a face recognition system. There are various distance measures in literature which are widely used in this area. In this work, a new class of similarity measure based on the Lp metric between fuzzy sets is proposed which gives better results when compared to the existing distance measures in the area with Linear Discriminant Analysis (LDA). The result points to a positive direction that with the existing feature extraction methods itself the results can be improved if the similarity measure in the matching part is efficient.

Multi-Threshold Algorithm Based on Havrda and Charvat Entropy for Edge Detection in Satellite Grayscale Images

Automatic edge detection of an image is considered a type of crucial information that can be extracted by applying detectors with different techniques. It is a main tool in pattern recognition, image segmentation, and scene analysis. This paper introduces an edge-detection algorithm, which generates multi-threshold values. It is based on non-Shannon measures such as Havrda & Charvat’s entropy, which is commonly used in gray level image analysis in many types of images such as satellite grayscale images. The proposed edge detection performance is compared to the previous classic methods, such as Roberts, Prewitt, and Sobel methods. Numerical results underline the robustness of the presented approach and different applications are shown.

Enhanced Face Detection Technique Based on Color Correction Approach and SMQT Features

Face detection is considered as a challenging problem in the field of image analysis and computer vision. There are many researches in this area, but because of its importance, it needs to be further developed. Successive Mean Quantization Transform (SMQT) for illumination and sensor insensitive operation and Sparse Network of Winnow (SNoW) to speed up the original classifier based face detection technique presented such a good result. In this paper we use the Mean of Medians of CbCr (MMCbCr) color correction approach to enhance the combined SMQT features and SNoW classifier face detection technique. The proposed technique is applied on color images gathered from various sources such as Internet, and Georgia Database. Experimental results show that the face detection performance of the proposed method is more effective and accurate compared to SFSC method.