Sorption Recovery of Lanthanum,Iron, Aluminum,and Calcium Ions from Phosphoric Acid

Russian Journal of Applied Chemistry - Sorption recovery of lanthanum, iron(III), aluminum, and calcium ions from phosphoric acid solutions with MTC 1600 macroporous sulfonic cation exchanger under...     

Alternating‐Current Measurements in Scanning Electrochemical Microscopy,Part 1: Principle and Theory

The development of the scanning electrochemical microscope in ac mode is presented from both experimental and theoretical point of views. The experiments are performed with the ferri/ferrocyanide redox mediator as model system. Based on analysis of the frequency‐dependent collection efficiency, diffusion between the probe and the substrate is investigated, and analysis of time constants allows evaluation of the size of the sensing area under investigation. The experimental results are in good agreement with numerical simulations.     

Output feedback guaranteed cost control of uncertain linear discrete systems with interval time-varying delays

This paper deals with output feedback guaranteed cost control problem for a general class of uncertain linear discrete delay systems, where the state and the observation output are subjected to interval time-varying delay. The proposed output feedback controller uses the observation measurement to exponentially stabilize the closed-loop system and guarantee an adequate level of system performance. By constructing a set of augmented Lyapunov–Krasovskii functionals, a delay-dependent condition for the robust output feedback guaranteed cost control is established in terms of linear matrix inequalities (LMIs). Three numerical examples are provided to demonstrate the efficiency of the proposed method.     

A procedure for designing linear functional observers

We present low-order functional observer existence conditions; the proposed existence conditions always lead to a design of functional observers of order less than or equal to that of a Luenberger observer. The proposed low-order observer always exists if a Luenberger observer exists.     

Exponential Convergence of Time-Delay Systems in the Presence of Bounded Disturbances

In this paper, the problem of control design for exponential convergence of state/input delay systems with bounded disturbances is considered. Based on the Lyapunov–Krasovskii method combining with the delay-decomposition technique, a new sufficient condition is proposed for the existence of a state feedback controller, which guarantees that all solutions of the closed-loop system converge exponentially (with a pre-specified convergence rate) within a ball whose radius is minimized. The obtained condition is given in terms of matrix inequalities with one parameter needing to be tuned, which can be solved by using a one-dimensional search method with Matlab’s LMI Toolbox to minimize the radius of the ball. Two numerical examples are given to illustrate the superiority of the proposed method.     

Enhancement of electrical stability of a-IGZO TFTs by improving the surface morphology and packing density of active channel

a-IGZO films were deposited on Si substrates by d.c sputtering technique with various working power densities (p_d) in the range of 0.74–2.22 W/cm². The correlation between material properties and their effects on electrical stability of a-IGZO thin-film transistor (TFTs) was studied as a function of p_d. At a p_d of 1.72 W/cm² a-IGZO film had smoothest surface roughness (0.309 nm) with In-rich and Ga-poor cation compositions as a channel. This structurally ordered TFTs exhibited a high field effect mobility of 9.14 cm²/Vs, a sub-threshold swing (S.S.) of 0.566 V/dec, and an on–off ratio of 10⁷. Additionally, the V_th shift in hysteresis loop is almost eliminated. It was shown that the densification of the a-IGZO film resulted in the reduction of its interface trap density (1.83 × 10¹² cm^?2), which contributes for the improvement in the electrical and thermal stability.     

DENSITY ESTIMATES FOR SOLUTIONS OF STOCHASTIC FUNCTIONAL DIFFERENTIAL EQUATIONS

In this article, we investigate the density of the solution to a class of stochastic functional differential equations by means of Malliavin calculus. Our aim is to provide upper and lower Gaussian estimates for the density.     

Synthesis and antifungal activity of chitosan-silver nanocomposite synergize fungicide against Phytophthora capsici

Fungicides are important tools for preventing pathogens and maintaining crop quality; however, their effectiveness was directly affected by high-priced, toxicity, and environmental pollution. As a result, it is necessary to get a safe and efficient antimicrobial agent against agricultural pathogens. In this study, silver-incorporated chitosan nanocomposites (Ag@CS) were first prepared in which CS was used as reducing and stabilizing agent and then these nanocomposites was synergized with fungicide Antracol (An), Ag@CS/An, against Phytophthora capsici causing Phytophthora blight in pepper. The obtained nanocomposites were characterized by Fourier transform infrared (FTIR), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and transmission electron microscopy (TEM). These results showed that Ag@CS and Ag@CS/An were successfully synthesized with spherical shape AgNPs having diameter of 20.3?±?0.7?nm and 44.6?±?0.3?nm, respectively. More importantly, Ag@CS/An was found to have significantly stronger antifungal ability than each component alone, analyzed by agar diffusion method. It might be anticipated that Ag@CS/An has a promising future as nano-antibiotic materials for agriculture.