Conditional stability of multi-solitons for the 1D NLKG equation with double power nonlinearity

The acid-base and optical properties of Chromazurol S and Eriochromazurol B in the presence of 1 . 10-6 - 2 . 10-2M solutions of cetylpyridinium bromide, cetyltrimethylammonium bromide and 1-ethoxycarbonylpentadecyltrimethylammonium bromide (Septonex) and 0.001-1.0% w/v solutions of octylphenolpolyethylene glycol ether (Triton X-100), polyoxyethylenemonolauryl ether (Brij 35) and lauryl sulphate sodium salt were determined by graphical and numerical interpretation of absorbance curves. The poorly soluble ion associates, which can be extracted into chloroform and which have the defined composition [LH4-nn-.n T+] or [LH3-nn-.n T+] are formed at submicellar concentration of the tenside. In regions close to the critical micellar concentration of the tenside, soluble binary complexes of the acid-base forms of the reagent are formed with tenside micelles. The conditional stability constants of the reagent acid-base equilibrium depend on the type and concentration of the tenside, on the reagent concentration, on the concentration and type of inorganic acid anions and on the ionic strength of the solution. The mechanism of interaction of the reagent with the tenside and the probable structure of the binary species are discussed.

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Existence of Odd Solutions to Boundary Value Problems with Power Nonlinearity

Journal of Mathematical Sciences ◽

10.1007/s10958-021-05236-2 ◽

2021 ◽

Vol 253 (3) ◽

pp. 382-390

Author(s):

Kh. A. Khachatryan ◽

A. K. Kroyan

Keyword(s):

Boundary Value Problems ◽

Boundary Value ◽

Power Nonlinearity

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Inverse problems for stochastic parabolic equations with additive noise

Journal of Inverse and Ill-Posed Problems ◽

10.1515/jiip-2017-0003 ◽

2020 ◽

Vol 29 (1) ◽

pp. 93-108

Author(s):

Ganghua Yuan

Keyword(s):

Inverse Problems ◽

Parabolic Equations ◽

Additive Noise ◽

Stability Result ◽

Main Tool ◽

Conditional Stability ◽

Final Time ◽

History Of ◽

Global Carleman Estimate ◽

Stochastic Parabolic Equation

Abstract In this paper, we study two inverse problems for stochastic parabolic equations with additive noise. One is to determinate the history of a stochastic heat process and the random heat source simultaneously by the observation at the final time 𝑇. For this inverse problem, we obtain a conditional stability result. The other one is an inverse source problem to determine two kinds of sources simultaneously by the observation at the final time and on the lateral boundary. The main tool for solving the inverse problems is a new global Carleman estimate for the stochastic parabolic equation.

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Studies on the Coordination Reaction of VO2+ and Tannic Acid in the Tannin Extract Desulfurization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.239-240.1573 ◽

2012 ◽

Vol 239-240 ◽

pp. 1573-1576

Author(s):

Zhu Qing Gao ◽

Xiao Dong Cai ◽

Kai Cheng Ling

Keyword(s):

Stability Constants ◽

Tannic Acid ◽

Ph Value ◽

Protonation Constants ◽

Conditional Stability ◽

Tannin Extract ◽

Acid Effect ◽

Different Temperatures ◽

The Stability ◽

Apparent Stability

At different temperatures, the protonation constants of tannic acid and the complex apparent stability constants between tannic acid and VO2+ were determined by using pH potentimetric method. The results showed that the protonation constants and the complex apparent stability constants slightly decreased with the raising temperature. In accordance with the pH value in the tannin extract technology, the conditional stability constants of the complex were calculated on the basis of the acid effect of tannic acid and the hydrolysis effect of VO2+. It was found that pH greatly affected the stability constants of the complex , so pH must be strictly controlled in the tannin extract technology.

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Spectrophotometric determination of dothiepin hydrochloride in pharmaceuticals through ion-pair complexation reaction

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq111009010a ◽

2012 ◽

Vol 18 (2) ◽

pp. 339-347 ◽

Cited By ~ 4

Author(s):

Sameer Abdulrahman ◽

Kanakapura Basavaiah

Keyword(s):

Ion Pair ◽

Pure Form ◽

Bromocresol Green ◽

Bromophenol Blue ◽

Complexation Reaction ◽

Conditional Stability ◽

Conditional Stability Constant ◽

Accuracy And Precision ◽

Significant Difference

Two simple, sensitive and extraction-free spectrophotometric methods are described for the determination of dothiepin hydrochloride (DOTH) both in pure form and in pharmaceutical tablets. The methods are based on ion-pair complex formation between dothiepin base (DOT) and two acidic dyes, namely, bromophenol blue (BPB) or bromocresol green (BCG) with absorption maximum at 425 nm for BPB method or 430 nm for BCG method. Beer?s law is obeyed over the concentration ranges of 1.0-15.0 and 1.0-17.5 ?g mL-1 DOT for BPB and BCG methods, respectively. The molar absorptivity values and Sandell?s sensitivity values are reported for both methods. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.18 and 0.53 ?g mL-1 for BPB method, and 0.17 and 0.50 ?g mL-1 for BCG method, respectively. The stoichiometry of the complex in either case was found to be 1: 1 and the conditional stability constant (KF) of the complexes has also been calculated. The proposed methods were applied successfully to the determination of DOTH in pure form and in its tablet form with good accuracy and precision. Statistical comparison of the results was performed using Student's t-test and variance ratio F-test at 95% confidence level and there was no significant difference between the official and proposed methods with regard to accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique.

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Determination of the complexation properties of a crosslinked poly(acrylic acid) gel with copper(II), nickel(II), and lead(II) in dilute aqueous solution

Canadian Journal of Chemistry ◽

10.1139/v01-059 ◽

2001 ◽

Vol 79 (4) ◽

pp. 370-376 ◽

Cited By ~ 5

Author(s):

Catherine Morlay ◽

Yolande Mouginot ◽

Monique Cromer ◽

Olivier Vittori

Keyword(s):

Aqueous Solution ◽

Ionic Strength ◽

Acrylic Acid ◽

Metal Ion ◽

Conditional Stability ◽

Binding Properties ◽

Complex Species ◽

Complexing Capacity ◽

Dilute Aqueous Solution ◽

Poly Acrylic Acid

The possible removal of copper(II), nickel(II), or lead(II) by an insoluble crosslinked poly(acrylic acid) was investigated in dilute aqueous solution. The binding properties of the polymer were examined at pH = 6.0 or 4.0 with an ionic strength of the medium µ = 0.1 or 1.0 M (NaNO3) using differential pulse polarography as an investigation means. The highest complexing capacity of the polyacid was obtained with lead(II) at pH = 6.0 with µ = 0.1 M, 4.8 mmol Pb(II)/g polymer. The conditional stability constants of the complex species formed were determined using the method proposed by Ruzic assuming that only the 1:1 complex species was formed; for lead(II) at pH = 6.0 and µ = 0.1 M, log K' = 5.3 ± 0.2. It appeared that the binding properties of the polymer increased, depending on the metal ion, in the following order: Ni(II) < Cu(II) < Pb(II). The complexing capacity and log K' values decreased with the pH or with an increase of the ionic strength. These results were in agreement with the conclusions of our previous studies of the hydrosoluble linear analogues. Finally, with the insoluble polymer, the log K' values were comparable to those previously obtained with the linear analogue whereas the complexing capacity values expressed in mmol g-1 were slightly lower.Key words: insoluble crosslinked poly(acrylic acid), copper(II), nickel(II), and lead(II) complexation.

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