Temperature and Frequency Dependent Dielectric Properties of Cu0.5Tl0.5Ba2Ca3(Cu4−y Cd y )O12−δ Bulk Superconductor

The temperature and frequency dependent dielectric properties of polycrystalline Cd-doped Cu_0.5Tl_0.5Ba₂Ca₃(Cu_4?y Cd _y )O_12?δ (y=0,0.25,0.5,0.75) bulk superconductor samples are investigated. The zero resistivity critical temperature {T _c(R=0)} has decreased and normal state resistivity has increased with the increase of Cd-doping in Cu_0.5Tl_0.5Ba₂Ca₃(Cu_4?y Cd _y )O_12?δ samples. The dielectric properties such as dielectric constants (ε′,ε″), dielectric loss tangent (tanδ) and ac-conductivity (σ _ac ) are investigated by measuring the capacitance (C) and conductance (G) in the frequency range of 10 KHz to 10 MHz at different temperature from 80 K to 300 K. The negative capacitance (NC) is observed in all Cu_0.5Tl_0.5Ba₂Ca₃(Cu_4?y Cd _y )O_12?δ samples. The large values of NC observed at lower frequencies and temperatures may be due to reduced thermal vibrations and enhanced polarizability of the material. The effect of Cd-doping on bulk properties, dc-resistivity (ρ) and ac-electrical conductivity (σ _ac ) of these superconductor samples are investigated. The polarization in Cu_0.5Tl_0.5Ba₂Ca₃(Cu_4?y Cd _y )O_12?δ samples is most likely arising from the displacement of charges in CuO₂/CdO₂ planes relative to the static charges at Ba²⁺, Tl³⁺, and Cu²⁺ sites in Cu_0.5Tl_0.5Ba₂O_4?δ charge reservoir layers by external applied field.     

Synthesis and properties of aqueous polyurethane dispersions: Influence of molecular weight of polyethylene glycol

Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness. A series of aqueous polyurethane dispersions containing carboxylate anion as hydrophilic pendant groups were synthesized through step growth polymerization reaction using hexamethylene diisocyanate (HDI), 1,4-butanediol (1,4-BDO), dimethylol propionic acid (DMPA) and polyethylene glycol (PEG) of different molecular weight. Effect of PEG molecular weight was investigated on molecular structure, contact angle measurement, and physical and adhesive properties of PU emulsions. Fourier transform infrared spectroscopy (FT-IR) was used to check the completion of polymerization reaction. Contact angle measurement indicated that the hydrophilicity of polymer increases by increasing molecular weight of PEG with a corresponding decrease in contact angle. Results of T-peel test showed a decrease in peel strength by increasing molecular weight of PEG. Moreover, solid contents%, drying time and storage stability suggested fast drying properties and greater stability of aqueous PU dispersions.     

A novel anti-windup framework for cascade control systems: An application to underactuated mechanical systems

This paper describes the anti-windup compensator (AWC) design methodologies for stable and unstable cascade plants with cascade controllers facing actuator saturation. Two novel full-order decoupling AWC architectures, based on equivalence of the overall closed-loop system, are developed to deal with windup effects. The decoupled architectures have been developed, to formulate the AWC synthesis problem, by assuring equivalence of the coupled and the decoupled architectures, instead of using an analogy, for cascade control systems. A comparison of both AWC architectures from application point of view is provided to consolidate their utilities. Mainly, one of the architecture is better in terms of computational complexity for implementation, while the other is suitable for unstable cascade systems. On the basis of the architectures for cascade systems facing stability and performance degradation problems in the event of actuator saturation, the global AWC design methodologies utilizing linear matrix inequalities (LMIs) are developed. These LMIs are synthesized by application of the Lyapunov theory, the global sector condition and the _?2${?}_2$ gain reduction of the uncertain decoupled nonlinear component of the decoupled architecture. Further, an LMI-based local AWC design methodology is derived by utilizing a local sector condition by means of a quadratic Lyapunov function to resolve the windup problem for unstable cascade plants under saturation. To demonstrate effectiveness of the proposed AWC schemes, an underactuated mechanical system, the ball-and-beam system, is considered, and details of the simulation and practical implementation results are described.     

Complex neutrosophic set

Complex fuzzy sets and complex intuitionistic fuzzy sets cannot handle imprecise, indeterminate, inconsistent, and incomplete information of periodic nature. To overcome this difficulty, we introduce complex neutrosophic set. A complex neutrosophic set is a neutrosophic set whose complex-valued truth membership function, complex-valued indeterminacy membership function, and complex-valued falsehood membership functions are the combination of real-valued truth amplitude term in association with phase term, real-valued indeterminate amplitude term with phase term, and real-valued false amplitude term with phase term, respectively. Complex neutrosophic set is an extension of the neutrosophic set. Further set theoretic operations such as complement, union, intersection, complex neutrosophic product, Cartesian product, distance measure, and δ-equalities of complex neutrosophic sets are studied here. A possible application of complex neutrosophic set is presented in this paper. Drawbacks and failure of the current methods are shown, and we also give a comparison of complex neutrosophic set to all such methods in this paper. We also showed in this paper the dominancy of complex neutrosophic set to all current methods through the graph.

     

Speech emotion recognition research: an analysis of research focus

This article analyses research in speech emotion recognition (“SER”) from 2006 to 2017 in order to identify the current focus of research, and areas in which research is lacking. The objective is to examine what is being done in this field of research. Searching on selected keywords, we extracted and analysed 260 articles from well-known online databases. The analysis indicates that SER research is an active field of research, dozens of articles being published each year in journals and conference proceedings. The majority of articles concentrate on three critical aspects of SER, namely (1) databases, (2) suitable speech features, and (3) classification techniques to maximize the recognition accuracy of SER systems. Having carried out association analysis of the critical aspects and how they influence the performance of the SER system in term of recognition accuracy, we found that certain combination of databases, speech features and classifiers influence the recognition accuracy of the SER system. We have also suggested aspects of SER that could be taken into consideration in future works based on our review.     

Neutrosophic triplet group

Groups are the most fundamental and rich algebraic structure with respect to some binary operation in the study of algebra. In this paper, for the first time, we introduced the notion of neutrosophic triplet which is a group of three elements that satisfy certain properties with some binary operation. These neutrosophic triplets highly depends on the defined binary operation. Further, in this paper, we utilized these neutrosophic triplets to introduce the innovative notion of neutrosophic triplet group which is completely different from the classical group in the structural properties. A big advantage of neutrosophic triplet is that it gives a new group (neutrosophic triplet group) structure to those algebraic structures which are not group with respect to some binary operation in the classical group theory. In neutrosophic triplet group, we apply the fundamental law of Neutrosophy that for an idea A, we have neutral of A denoted as neut(a) and anti of A denoted as anti(A) to capture this beautiful picture of neutrosophic triplet group in algebraic structures. We also studied some interesting properties of this newly born structure. We further defined neutro-homomorphisms for neutrosophic triplet groups. A neutron-homomorphism is the generalization of the classical homomorphism with two extra conditions. As a further generalization, we gave rise to a new field or research called Neutrosophic Triplet Structures (such as neutrosophic triplet ring, neutrosophic triplet field, neutrosophic triplet vector space, etc.). In the end, we gave main distinctions and comparison of neutrosophic triplet group with the classical Molaei’s generalized group as well as the possible application areas of the neutrosophic triplet groups.

     

Forecasting Daily Flood Water Level Using Hybrid Advanced Machine Learning Based Time-Varying Filtered Empirical Mode Decomposition Approach

Water Resources Management - Accurate water level forecasting is important to understand and provide an early warning of flood risk and discharge. It is also crucial for many plants and animal...     

Flux Pinning with Addition of Gold Nanoparticles in CuTl-1223 Superconductor

We investigated the effects of gold (Au) nanoparticles on flux pinning in Cu_0.5Tl_0.5Ba₂Ca₂Cu₃O_10?δ (CuTl-1223) superconductor by infield temperature-dependent dc-resistivity measurements. The values of \(\phantom {\dot {i}\!}T_{\mathrm {c}}^{\text {onset}}\) (K) remained almost unaffected by applying external magnetic field on (Au) _x /CuTl-1223; (x = 0～1.5 wt.%) composites samples. But a decreasing trend in T _c(0) and increasing trend in resistive broadening (ΔT) by increasing external applied magnetic field were reduced after addition of Au nanoparticles in CuTl-1223 superconducting matrix. The activation energy (U _o) was calculated according to thermally activated flux flow (TAFF) model by using the Arrhenius Law. The increase in T _c(0), U _o, and upper critical field (H _c2) indicates a strong flux pinning after the inclusion of Au nanoparticles and found optimum for x = 1.0 wt.%.     

Effect of Surfactants and Temperature on Adsorption Behavior of Metal Ions on Organic–Inorganic Hybrid Exchanger,Acrylamide Aluminum Tungstate

The adsorption behavior of a thermally and chemically stable hybrid ion-exchange material, acrylamide aluminum tungstate was explored in cationic (CTAB) and anionic (SDS) surfactants and acidic solvents. Critical micellar concentration (CMC) appears to be an important parameter in determining the adsorption behavior of metal ions. Equilibration time and temperature studies on the distribution coefficient of metal ions were studied. On the basis of the distribution coefficient, this material was successfully used for quantitative separations of some binary synthetic mixtures of metal ions by the column method. Hg(II) ion was selectively determined quantitatively in synthetic mixture. The material appears to be promising for separating toxic metal ions in a real matrix (industrial effluents and waste water) and can be utilized as a packing material in HPLC and GC columns for faster and more efficient separation.