Features of the Influence of the Initial Composition of Organic Stratifying Mixtures in Microsized Pores on the Mutual Solubility of Components

A chemical system is proposed that is capable of amplifying small optical inputs into large changes in internal composition, based on a feedback interaction between switchable fluorescence and visible-light photoswitching. This system would demonstrate bifurcating reaction kinetics under irradiation and reach one of two stable photostationary states depending on the initial composition of the system. This behavior would allow the system to act as a chemical realization of the flip-flop circuit, the fundamental element in sequential logic and binary memory storage. We use detailed numerical modeling to demonstrate the feasibility of the proposed behavior based on known molecular phenomena, and comment on some of the conditions required to realize this system.

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The effect of systematic errors of the equilibrium distribution concentrations on the number of stages of countercurrent extraction with various consumption of extractant

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19890981 ◽

1989 ◽

Vol 54 (4) ◽

pp. 981-989

Author(s):

Ján Dojčanský ◽

Soňa Bafrncová ◽

Július Surový

Keyword(s):

Equilibrium Distribution ◽

Systematic Errors ◽

Mutual Solubility ◽

Operating Conditions ◽

Liquid Equilibrium ◽

Countercurrent Extraction ◽

Absolute Deviation ◽

Line Slope ◽

Tie Line ◽

Calculated Number

On using five hypothetical systems differing in the extent of mutual solubility of components, tie-line slope, and type of binodal curve, the effect is evaluated of systematic errors in the form of absolute deviation in the liquid-liquid equilibrium distribution concentrations on the accuracy of calculated number of theoretical stages of isothermal countercurrent extraction under various operating conditions.

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Rate of convergence for traditional Pólya urns

Journal of Applied Probability ◽

10.1017/jpr.2020.59 ◽

2020 ◽

Vol 57 (4) ◽

pp. 1029-1044

Author(s):

Svante Janson

Keyword(s):

Rate Of Convergence ◽

Dirichlet Distribution ◽

Fixed Number ◽

Kolmogorov Distance ◽

Initial Composition ◽

Exact Distributions ◽

Polya Urn ◽

The One ◽

Lévy Distance ◽

Direct Calculations

AbstractConsider a Pólya urn with balls of several colours, where balls are drawn sequentially and each drawn ball is immediately replaced together with a fixed number of balls of the same colour. It is well known that the proportions of balls of the different colours converge in distribution to a Dirichlet distribution. We show that the rate of convergence is $\Theta(1/n)$ in the minimal $L_p$ metric for any $p\in[1,\infty]$, extending a result by Goldstein and Reinert; we further show the same rate for the Lévy distance, while the rate for the Kolmogorov distance depends on the parameters, i.e. on the initial composition of the urn. The method used here differs from the one used by Goldstein and Reinert, and uses direct calculations based on the known exact distributions.

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Diffusive layering during film growth in two-component systems with limited mutual solubility

10.1117/12.390594 ◽

2000 ◽

Author(s):

Grigory V. Merkulov ◽

Valentin M. Ievlev ◽

Evgeny V. Shvedov ◽

Vadim P. Ampilogov

Keyword(s):

Film Growth ◽

Mutual Solubility ◽

Component Systems ◽

Two Component ◽

Two Component Systems

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Comparison of Three Accelerated Oxidation Tests Applied to Red Wines with Different Chemical Composition

Molecules ◽

10.3390/molecules26040815 ◽

2021 ◽

Vol 26 (4) ◽

pp. 815

Author(s):

Francesca Coppola ◽

Luigi Picariello ◽

Martino Forino ◽

Luigi Moio ◽

Angelita Gambuti

Keyword(s):

Red Wine ◽

Phenolic Composition ◽

Red Wines ◽

Initial Composition ◽

Accelerated Oxidation ◽

Before And After ◽

Saturation Method ◽

Lower Variability ◽

Wine Oxidation ◽

Wine Color

Background: Three accelerated oxidation tests were proposed to simulate red wine oxidation thus providing information useful to correctly manage moderate oxygen exposure of wine during aging in regard to phenolic composition and wine color. Since the results of the tests have never been compared on wines with different initial composition, the aim of this study was to find a suitable method to simulate oxidation of any still red wine. Methods: Aglianico, Barbera, Gaglioppo, Magliocco, and Nerello wines were treated with (1) three cycles of air saturation, (2) the addition of hydrogen peroxide, and (3) the addition of acetaldehyde. Changes in chromatic characteristics and phenolic composition were determined by spectrophotometric and HPLC methods. Results: Important differences in the behavior of the different wines were detected: the highest formation of polymeric pigments was observed in Barbera and Aglianico wines. In contrast, Gaglioppo and Magliocco wines showed a lower variability before and after the oxidation probably due to the lower anthocyanin/tannin ratio. Among the accelerated oxidation tests applied, no significant differences in color parameters and phenolic composition were detected in samples treated with the addition of H2O2 and the air saturation method. Conclusion: The study demonstrated that H2O2 addition is a successful tool to predict the evolution of different phenolic compounds during the air saturation treatment of wines.

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Comparison between Pressurized Liquid Extraction and Conventional Soxhlet Extraction for Rosemary Antioxidants, Yield, Composition, and Environmental Footprint

Foods ◽

10.3390/foods9050584 ◽

2020 ◽

Vol 9 (5) ◽

pp. 584 ◽

Cited By ~ 5

Author(s):

Mathilde Hirondart ◽

Natacha Rombaut ◽

Anne Sylvie Fabiano-Tixier ◽

Antoine Bily ◽

Farid Chemat

Keyword(s):

Extraction Procedure ◽

Soxhlet Extraction ◽

Liquid Extraction ◽

Raw Material ◽

Pressurized Liquid Extraction ◽

Carnosic Acid ◽

Environmental Footprint ◽

Initial Composition ◽

Significant Difference ◽

Preparation Step

Nowadays, “green analytical chemistry” challenges are to develop techniques which reduce the environmental impact not only in term of analysis but also in the sample preparation step. Within this objective, pressurized liquid extraction (PLE) was investigated to determine the initial composition of key antioxidants contained in rosemary leaves: Rosmarinic acid (RA), carnosic acid (CA), and carnosol (CO). An experimental design was applied to identify an optimized PLE set of extraction parameters: A temperature of 183 °C, a pressure of 130 bar, and an extraction duration of 3 min enabled recovering rosemary antioxidants. PLE was further compared to conventional Soxhlet extraction (CSE) in term of global processing time, energy used, solvent recovery, raw material used, accuracy, reproducibility, and robustness to extract quantitatively RA, CA, and CO from rosemary leaves. A statistical comparison of the two extraction procedure (PLE and CSE) was achieved and showed no significant difference between the two procedures in terms of RA, CA, and CO extraction. To complete the study showing that the use of PLE is an advantageous alternative to CSE, the eco-footprint of the PLE process was evaluated. Results demonstrate that it is a rapid, clean, and environmentally friendly extraction technique.

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