The role of hydrogen bonds in thermodynamic and structural properties in binary mixtures of morpholine + 2-methylcyclohexanol: a combined experimental and computational study

This article discusses information on the study of terminology in Uzbek and world linguistics. Thematic grouping of banking and financial terms, which play an important role in Uzbek language vocabulary, is considered. The author gives the criteria for the distribution of terms into thematic groups, their peculiar properties examples to substantiate the hypothesis. The paradigmatic relations between the terms of this sphere are indicated. A structural analysis of the banking and financial terms of the Uzbek language is carried out. On the basis of the anthropocentric approach, the role of the human factor in the banking and financial terminology of the Uzbek language is studied. Cognitive metaphors that exist in the terminology are considered.

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Density Functional Theory (B3LYP) Study of Substituent Effects on O–H Bond Dissociation Enthalpies of trans-Resveratrol Derivatives and the Role of Intramolecular Hydrogen Bonds

The Journal of Organic Chemistry ◽

10.1021/jo301612a ◽

2012 ◽

Vol 77 (22) ◽

pp. 10093-10104 ◽

Cited By ~ 15

Author(s):

Elyas Nazarparvar ◽

Mansour Zahedi ◽

Erik Klein

Keyword(s):

Density Functional Theory ◽

Hydrogen Bonds ◽

Density Functional ◽

Substituent Effects ◽

Functional Theory ◽

Intramolecular Hydrogen Bonds ◽

Bond Dissociation ◽

Resveratrol Derivatives ◽

Intramolecular Hydrogen

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On the Role of Marangoni Effects on the Critical Heat Flux for Pool Boiling of Binary Mixtures

Journal of Heat Transfer ◽

10.1115/1.2824021 ◽

1996 ◽

Vol 118 (1) ◽

pp. 103-109 ◽

Cited By ~ 52

Author(s):

W. R. McGillis ◽

V. P. Carey

Keyword(s):

Surface Tension ◽

Heat Flux ◽

Binary Mixtures ◽

Critical Heat Flux ◽

Full Range ◽

Pool Boiling ◽

Marangoni Effect ◽

Restoring Force ◽

Marangoni Effects

The Marangoni effect on the critical heat flux (CHF) condition in pool boiling of binary mixtures has been identified and its effect has been quantitatively estimated with a modified model derived from hydrodynamics. The physical process of CHF in binary mixtures, and models used to describe it, are examined in the light of recent experimental evidence, accurate mixture properties, and phase equilibrium revealing a correlation to surface tension gradients and volatility. A correlation is developed from a heuristic model including the additional liquid restoring force caused by surface tension gradients. The CHF condition was determined experimentally for saturated methanol/water, 2-propanol/water, and ethylene glycol/water mixtures, over the full range of concentrations, and compared to the model. The evidence in this study demonstrates that in a mixture with large differences in surface tension, there is an additional hydrodynamic restoring force affecting the CHF condition.

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Dynamical evolution of multiple-population globular clusters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab223 ◽

2021 ◽

Vol 502 (3) ◽

pp. 4290-4304

Author(s):

Enrico Vesperini ◽

Jongsuk Hong ◽

Mirek Giersz ◽

Arkadiusz Hypki

Keyword(s):

Structural Properties ◽

Globular Clusters ◽

First Generation ◽

Radial Profile ◽

Dynamical Evolution ◽

Evolutionary Phase ◽

Dynamical Parameters ◽

Energy Equipartition

ABSTRACT We have carried out a set of Monte Carlo simulations to study a number of fundamental aspects of the dynamical evolution of multiple stellar populations in globular clusters with different initial masses, fractions of second generation (2G) stars, and structural properties. Our simulations explore and elucidate: (1) the role of early and long-term dynamical processes and stellar escape in the evolution of the fraction of 2G stars and the link between the evolution of the fraction of 2G stars and various dynamical parameters; (2) the link between the fraction of 2G stars inside the cluster and in the population of escaping stars during a cluster’s dynamical evolution; (3) the dynamics of the spatial mixing of the first-generation (1G) and 2G stars and the details of the structural properties of the two populations as they evolve toward mixing; (4) the implications of the initial differences between the spatial distribution of 1G and 2G stars for the evolution of the anisotropy in the velocity distribution and the expected radial profile of the 1G and 2G anisotropy for clusters at different stages of their dynamical history; and (5) the variation of the degree of energy equipartition of the 1G and the 2G populations as a function of the distance from the cluster’s centre and the cluster’s evolutionary phase.

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Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽

10.3390/gels7020048 ◽

2021 ◽

Vol 7 (2) ◽

pp. 48

Author(s):

Ana M. Herrero ◽

Claudia Ruiz-Capillas

Keyword(s):

Raman Spectroscopy ◽

Structural Properties ◽

Structural Changes ◽

Protein Secondary Structure ◽

Lipid Phase ◽

Α Helix ◽

Β Sheet ◽

Shed Light ◽

Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

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Crystal Packing Modulation of the Strength of Resonance-Assisted Hydrogen Bonds and the Role of Resonance-Assisted Pseudoring Stacking in Geminal Amido Esters: Study Based on Crystallography and Theoretical Calculations

Crystal Growth & Design ◽

10.1021/acs.cgd.0c01010 ◽

2020 ◽

Author(s):

Perumal Venkatesan ◽

Subbiah Thamotharan ◽

M. Judith Percino ◽

Andivelu Ilangovan

Keyword(s):

Hydrogen Bonds ◽

Crystal Packing ◽

Theoretical Calculations

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The Activating Effect of Strong Acid for Pd-Catalyzed Directed C–H Activation by Concerted Metalation-Deprotonation Mechanism

Molecules ◽

10.3390/molecules26134083 ◽

2021 ◽

Vol 26 (13) ◽

pp. 4083

Author(s):

Heming Jiang ◽

Tian-Yu Sun

Keyword(s):

Activation Energy ◽

Dft Calculations ◽

Energy Barrier ◽

Computational Study ◽

Strong Acid ◽

Activation Energy Barrier ◽

Pd Catalysts ◽

Acid Ligand ◽

Strong Acids

A computational study on the origin of the activating effect for Pd-catalyzed directed C–H activation by the concerted metalation-deprotonation (CMD) mechanism is conducted. DFT calculations indicate that strong acids can make Pd catalysts coordinate with directing groups (DGs) of the substrates more strongly and lower the C–H activation energy barrier. For the CMD mechanism, the electrophilicity of the Pd center and the basicity of the corresponding acid ligand for deprotonating the C–H bond are vital to the overall C–H activation energy barrier. Furthermore, this rule might disclose the role of some additives for C–H activation.

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Antioxidant Properties of Ergosterol and Its Role in Yeast Resistance to Oxidation

Antioxidants ◽

10.3390/antiox10071024 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1024

Author(s):

Sebastien Dupont ◽

Paul Fleurat-Lessard ◽

Richtier Gonçalves Cruz ◽

Céline Lafarge ◽

Cédric Grangeteau ◽

...

Keyword(s):

Computational Study ◽

Antioxidant Properties ◽

Beneficial Effects ◽

Tert Butyl Hydroperoxide ◽

Resistance To Oxidation ◽

Specific Accumulation ◽

The Subject

Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl hydroperoxide and protects lipids against oxidation in liposomes. A computational study based on quantum chemistry revealed that this protection could be related to its antioxidant properties operating through an electron transfer followed by a proton transfer mechanism. This study demonstrates the antioxidant role of ergosterol and proposes knowledge elements to explain the specific accumulation of this sterol in late branching fungi. Ergosterol, as a natural antioxidant molecule, could also play a role in the incompletely understood beneficial effects of some mushrooms on health.

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