Theoretical Models for Quantitative Description of the Acid–Base Equilibria of the 5,6-Substituted Uracils

2017 ◽  
Vol 122 (1) ◽  
pp. 341-349 ◽  
Author(s):  
Margarita G. Ilyina ◽  
Edward M. Khamitov ◽  
Sergey P. Ivanov ◽  
Akhat G. Mustafin ◽  
Sergey L. Khursan
Keyword(s):  
Quantitative Description ◽  
Theoretical Models ◽  
Acid Base ◽  
Substituted Uracils

Theoretical models for acid-base equilibrium data in nonaqueous solvents

1972 ◽  
Vol 76 (24) ◽  
pp. 3618-3625 ◽  
Author(s):  
Neal G. Sellers ◽  
Peter M. P. Eller ◽  
Joseph A. Caruso
Keyword(s):  
Theoretical Models ◽  
Nonaqueous Solvents ◽  
Acid Base ◽  
Base Equilibrium ◽  
Acid Base Equilibrium ◽  
Equilibrium Data

scholarly journals On the Interaction between 1D Materials and Living Cells

2020 ◽  
Vol 11 (2) ◽  
pp. 40
Author(s):  
Giuseppe Arrabito ◽  
Yana Aleeva ◽  
Vittorio Ferrara ◽  
Giuseppe Prestopino ◽  
Clara Chiappara ◽  
...  
Keyword(s):  
Quantitative Description ◽  
Biological Response ◽  
Traction Force ◽  
Theoretical Models ◽  
Cellular Membrane ◽  
Research Field ◽  
Material Chemistry ◽  
Cell Interface ◽  
Cellular Lysis

One-dimensional (1D) materials allow for cutting-edge applications in biology, such as single-cell bioelectronics investigations, stimulation of the cellular membrane or the cytosol, cellular capture, tissue regeneration, antibacterial action, traction force investigation, and cellular lysis among others. The extraordinary development of this research field in the last ten years has been promoted by the possibility to engineer new classes of biointerfaces that integrate 1D materials as tools to trigger reconfigurable stimuli/probes at the sub-cellular resolution, mimicking the in vivo protein fibres organization of the extracellular matrix. After a brief overview of the theoretical models relevant for a quantitative description of the 1D material/cell interface, this work offers an unprecedented review of 1D nano- and microscale materials (inorganic, organic, biomolecular) explored so far in this vibrant research field, highlighting their emerging biological applications. The correlation between each 1D material chemistry and the resulting biological response is investigated, allowing to emphasize the advantages and the issues that each class presents. Finally, current challenges and future perspectives are discussed.

scholarly journals Modern technologies of detection and prevention of corruption in emerging information society

2018 ◽  
Vol 16 (1) ◽  
pp. 58-67
Author(s):  
Natalia Maslii ◽  
Natalia Zakharchenko ◽  
Viktoriia Butenko ◽  
Oksana Savastieieva ◽  
Tetiana Butenko ◽  
...  
Keyword(s):  
Information Society ◽  
Quantitative Description ◽  
Theoretical Models ◽  
Mathematical Notation ◽  
Risk Models ◽  
Political Consequences ◽  
Accurate Picture ◽  
The World ◽  
Modern Technologies

With the development of the information society, there has been rapidly growing number of international research on the role of various (information, innovation, intelligent) technologies as a catalyst to fight corruption. As you know, the problems posed by corruption are economic, social and political consequences. In recent years economists and various researchers have shown increasing interest in studying the phenomenon of corruption. Many researchers in the field of studying corruption phenomenon are of theoretical nature, which studied different behaviors without having developed effective methods and technologies to identify and prevent corruption in the various spheres of government. In this regard, there is a need to study the world experience of application of technologies in the prevention of corruption and anti-corruption platform in Ukraine. This will allow to adapt them to positive experience in the implementation of mechanisms to identify and prevent corruption in Ukraine. The authors believe that to obtain a more accurate picture of the corruption situations that provide characteristics and its quantitative description is possible only by means of modelling the corruption phenomenon. In this regard, the analysis of theoretical models of corruption was made: the modelling made by the mathematical notation of the models and conclusions on the effectiveness of their application in management. Using simulation, the authors came to the conclusion that the detection and prevention of corruption should be carried out with the use of technologies and the system approach: from the study of statistics and use of anti-corruption platforms, public registers and databases to logical and probabilistic (LP) risk models of corruption.

Quantitative description of the changes in the acid-base properties of bromocresol green in the presence of submicelle and micelle concentrations of cationic tenside-Septonex

1983 ◽  
Vol 48 (5) ◽  
pp. 1290-1304 ◽  
Author(s):  
Josef Havel ◽  
Irena Burešová-jančářová ◽  
Vlastimil Kubáň
Keyword(s):  
Dissociation Constant ◽  
Equilibrium Constant ◽  
Dissociation Constants ◽  
Quantitative Description ◽  
Polymeric Micelle ◽  
Bromocresol Green ◽  
Acid Base ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Base Properties

The effect of cationic surface-active substances - tensides - on the acid-base and optical properties of anionic organic analytical reagents was studied by spectrophotometric methods on the example of bromocresol green with Septonex in the submicelle and micelle tenside concentration regions. The acid-base properties of bromocresol green under the given experimental conditions depend on the concentrations of the tenside and reagent and on the type and concentration of the inert electrolyte. Changes in the conditional dissociation constant of the reagent were quantitatively described by equations that were derived from the relationships for the dissociation constant of the acid-base transition of the reagent LH/L-, the equilibrium constant for formation of the stoichiometric ion-associates between the tenside T+ and the anionic acid-base form of the reagent L- or the anion of the inert electrolyte X- and the equilibrium constant for formation of the polymeric micelle aggregates (T+)n. The experimental values of the conditional dissociation constants for bromocresol green for various tenside or inert electrolyte concentrations are in good agreement with these theoretically derived relationships.

Acid base phenomena at the n-TiO2/room temperature molten salt interphase

1982 ◽  
Vol 47 (7) ◽  
pp. 1794-1801 ◽  
Author(s):  
R. J. Gale ◽  
A. J. Nozik ◽  
J. Cooper ◽  
R. A. Osteryoung
Keyword(s):  
Cyclic Voltammetry ◽  
Room Temperature ◽  
Surface Coverage ◽  
Dopant Concentration ◽  
Theoretical Models ◽  
Lewis Acidity ◽  
Flat Band ◽  
Acid Base ◽  
Surface Complexes ◽  
Multiple Ligand

Interphasial properties of the n-TiO2/room temperature AlCl3 : 1-butylpyridinium chloride melt system have been studied by cyclic voltammetry and ac impedance methods. Surface faradaic reactions, dependent on the Lewis acidity of the melt and the semiconductor dopant concentration, are thought to be due to ionizable surface complexes. Theoretical models for flat-band shifts with bulk electrolyte acidity may be complex if the surface coverage is variable or if multiple ligand ionization can occur.

Electrochemical and Spectrophotometric Study of the Reactions of L-Leucine with Pyridoxal and Pyridoxal Phosphate

1994 ◽  
Vol 59 (4) ◽  
pp. 768-781
Author(s):  
T. Pineda ◽  
M. Blázquez ◽  
M. Domínguez ◽  
F. Garcia-Blanco
Keyword(s):  
Amino Acid ◽  
Schiff Bases ◽  
Formation Constant ◽  
Pyridoxal Phosphate ◽  
Mercury Electrode ◽  
Quantitative Description ◽  
Spectrophotometric Study ◽  
Acid Base ◽  
Absorption Bands ◽  
Reduction Mechanisms

The reactions of L-leucine (Leu) with pyridoxal (PL) and pyridoxal-5'-phosphate (PLP) were studied over pH 6 - 13.5. Formation of the Schiff bases was indicated by UV-VIS absorption bands and reduction waves on a mercury electrode. A comparative electrochemical and spectrophotometric study on the reaction mixtures as a function of pH and the amino acid-to-aldehyde concentration ratio was carried out. Apparent formation constant, KpH and acid-base constants for the Schiff bases were obtained. Reduction mechanisms of the imines are proposed in different pH zones. The formation constant, KSo, of an unprotonated Schiff base from unprotonated species of aldehyde and amino acid was determined by voltammetry. The results are compared to those obtained in analog Schiff bases in order to improve the quantitative description of the enzymatic models.

Analytical Electron Microscopy of Surface-Modified Ceramics

1985 ◽  
Vol 43 ◽  
pp. 276-279
Author(s):  
P. S. Sklad
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Theoretical Models ◽  
Ceramic Materials ◽  
Solute Concentration ◽  
Second Phase ◽  
Analytical Electron ◽  
Implantation Techniques ◽  
Lattice Damage ◽  
Surface Modified

Over the past several years, it has become increasingly evident that materials for proposed advanced energy systems will be required to operate at high temperatures and in aggressive environments. These constraints make structural ceramics attractive materials for these systems. However it is well known that the condition of the specimen surface of ceramic materials is often critical in controlling properties such as fracture toughness, oxidation resistance, and wear resistance. Ion implantation techniques offer the potential of overcoming some of the surface related limitations.While the effects of implantation on surface sensitive properties may be measured indpendently, it is important to understand the microstructural evolution leading to these changes. Analytical electron microscopy provides a useful tool for characterizing the microstructures produced in terms of solute concentration profiles, second phase formation, lattice damage, crystallinity of the implanted layer, and annealing behavior. Such analyses allow correlations to be made with theoretical models, property measurements, and results of complimentary techniques.

High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

1996 ◽  
Vol 54 ◽  
pp. 1004-1005
Author(s):  
N. V. Larcher ◽  
I. G. Solorzano
Keyword(s):  
Discontinuous Precipitation ◽  
Equilibrium Phase ◽  
Quantitative Description ◽  
Present Contribution ◽  
Α Phase ◽  
The Matrix ◽  
Aging Sequence ◽  
Matrix Precipitation ◽  
Considerable Detail ◽  
Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

On the Relationship Between General Auditory Sensitivity and Speech Perception: An Examination of Pitch and Lexical Tone Perception in 4- to 6-Year-Old Children

2020 ◽  
Vol 63 (2) ◽  
pp. 487-498
Author(s):  
Puisan Wong ◽  
Man Wai Cheng
Keyword(s):  
Speech Perception ◽  
Theoretical Models ◽  
Developmental Trajectory ◽  
Auditory Sensitivity ◽  
Pitch Discrimination ◽  
Lexical Tone ◽  
Perceptual Training ◽  
Lexical Tones ◽  
Tone Perception ◽  
Tone Discrimination

Purpose Theoretical models and substantial research have proposed that general auditory sensitivity is a developmental foundation for speech perception and language acquisition. Nonetheless, controversies exist about the effectiveness of general auditory training in improving speech and language skills. This research investigated the relationships among general auditory sensitivity, phonemic speech perception, and word-level speech perception via the examination of pitch and lexical tone perception in children. Method Forty-eight typically developing 4- to 6-year-old Cantonese-speaking children were tested on the discrimination of the pitch patterns of lexical tones in synthetic stimuli, discrimination of naturally produced lexical tones, and identification of lexical tone in familiar words. Results The findings revealed that accurate lexical tone discrimination and identification did not necessarily entail the accurate discrimination of nonlinguistic stimuli that followed the pitch levels and pitch shapes of lexical tones. Although pitch discrimination and tone discrimination abilities were strongly correlated, accuracy in pitch discrimination was lower than that in tone discrimination, and nonspeech pitch discrimination ability did not precede linguistic tone discrimination in the developmental trajectory. Conclusions Contradicting the theoretical models, the findings of this study suggest that general auditory sensitivity and speech perception may not be causally or hierarchically related. The finding that accuracy in pitch discrimination is lower than that in tone discrimination suggests that comparable nonlinguistic auditory perceptual ability may not be necessary for accurate speech perception and language learning. The results cast doubt on the use of nonlinguistic auditory perceptual training to improve children's speech, language, and literacy abilities.

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