scholarly journals Chain breaking in the statistical mechanical constitutive theory of polymer networks

2021 ◽  
pp. 104593
Author(s):  
Michael R. Buche ◽  
Meredith N. Silberstein
Keyword(s):  
Polymer Networks ◽  
Constitutive Theory ◽  
Chain Breaking ◽  
Statistical Mechanical

ON CONSTRUCT OF THE RIGHT OF PRE-EMPTION IN RESPECT OF PARTICIPATORY INTEREST (SHARES)

2020 ◽  
Vol 20 (4) ◽  
pp. 94-219
Author(s):  
I.S. CHUPRUNOV
Keyword(s):  
General Rule ◽  
Constitutive Theory ◽  
Freedom Of Contract ◽  
Legal Nature ◽  
Public Corporation ◽  
Russian Law ◽  
Right Of First Refusal ◽  
The Right

The paper provides analysis of the legal nature and the mechanism for exercise of the right of pre-emption (right of first refusal) in respect of execution of a contract taking as an example of right of first refusal to purchase a stake in a non-public corporation, and also examines the boundaries of parties’ autonomy and freedom of contract in this area. The author comes to the conclusion that the key elements of the construction of the right of pre-emption are the transformation powers that belong to the right holder. The author also demonstrates that, notwithstanding their dominance in Russian law, the views, which suggest that exercise of the right of pre-emption leads to “transfer of rights and obligations of a purchaser” (the translative theory), should be rejected. These views must be replaced with the constitutive theory, according to which exercise of the right of pre-emption results in a new contract between the right holder and the seller (as a general rule, on the same terms that were agreed between the seller and the purchaser).

Interionic Pair Potential, hard sphere diameter and entropy of mixing of NaCd compound forming binary molten alloys under the framework of Pseudopotential theory

2014 ◽  
Vol 10 (6) ◽  
pp. 2843-2852
Author(s):  
Sujeet Kumar Chatterjee ◽  
Lokesh Chandra Prasad ◽  
Ajaya Bhattarai
Keyword(s):  
Nearest Neighbor ◽  
Effective Interaction ◽  
Pair Potential ◽  
Sphere Diameter ◽  
Compound Formation ◽  
Pseudopotential Theory ◽  
Energy Of Mixing ◽  
Asymmetric Behaviour ◽  
Statistical Mechanical ◽  
Free Energy Of Mixing

The observed asymmetric behaviour of mixing of  NaCd liquid alloys around equiatomic composition with smaller negative values for free energy of mixing at compound forming concentration, i.e. GMXS = -4.9KJ at Ccd =0.66 has  aroused our interest to undertake a theoretical investigation of this system.A simple statistical mechanical theory based on compound formation model has been used to investigate the energetics of formation of intermetallic compound Cd2Na in the melt through the study of entropy of mixing.Besides, the interionic interactions between component atoms Na and Cd of the alloys have been understood through the study of interionic pair potential фij(r), calculated from pseudopotential theory in the light of CF model.Our study of фij(r) suggest that the effective interaction between Na-Na atoms decreases on alloying with Cd atom, being minimum for compound forming alloy( Cd 0.66 Na 0.34 ).The nearest neighbor distance between Na-Na atoms does not alter on alloying. Like wise Na-Na,  effective interaction between  Cd-Cd atom decreases from pure state to NaCd alloys, being smaller at compound forming  concentration Cd 0.66 Na 0.34.The computed values of SM from pseudopotential theory are positive at all concentrations, but the agreement between theory and experimental is not satisfactory. This might be happening due to parameterisation of σ3 and Ψcompound.

Crosslinker Chemistry Determines the Uptake Potential of Perfluorinated Alkyl Substances by β-Cyclodextrin Polymers

2018 ◽  
Author(s):  
Leilei Xiao ◽  
Casey Ching ◽  
Yuhan Ling ◽  
Mohammadreza Nasiri ◽  
Max Justin Klemes ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Polymer Networks ◽  
Cyclodextrin Polymer ◽  
Perfluorinated Alkyl Substances ◽  
Cyclodextrin Polymers

This work describes several crosslinked β-cyclodextrin polymer networks and correlates the crosslinker chemistry with binding affinity for per- and polyfluorinated alkyl substances (PFASs), including PFOA and PFOS.

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

Chain-breaking/Preventive Antioxidant, Urate-lowering, and Anti-inflammatory Effects of Pure Curcumin

2020 ◽  
Vol 17 (1) ◽  
pp. 66-74
Author(s):  
Seghira Bisset ◽  
Widad Sobhi ◽  
Chawki Bensouici ◽  
Abdelhalim Khenchouche
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Acid Production ◽  
Biological Activities ◽  
Antioxidant Effect ◽  
Metal Chelating ◽  
Wide Range ◽  
Chain Breaking ◽  
Pharmaceutical Industries ◽  
Anti Inflammatory

Background: Several researches have shown that therapeutic compounds or phytochemicals from natural sources are important in the food as it is valuable in pharmaceutical industries due to their fewer side effects and potent against various diseases. Curcumin, a major polyphenol derived from turmeric spice, which used in many foods, has a wide range of biological activities, with quite a safety. Objective: The goal of this study was to investigate the antioxidant, urate-lowering, and antiinflammatory effects of pure curcumin. Methods: The antioxidant activity was evaluated for chain-breaking antioxidant effect (radicalscavenging and reducing abilities assays) and for preventive antioxidant effect with metal chelating assay, the urate-lowering was assayed on aspectrophotometer by measuring the inhibition of uric acid production by xanthine oxidase (XO) enzyme, and the anti-inflammatory effect was estimated using in vitro albumin denaturation inhibition. Results: Curcumin showed a significant and good chain-breaking antioxidant effect, both in free radical- scavenging assays (Galvinoxyl radical, ABTS, and hydroxyl radical), and in reducing abilities methods (reducing power, Cupric ion reducing antioxidant capacity and O-phenanthroline assays). In preventive antioxidant effect, assessed with the metal chelating assay, curcumin showed significant effect but with high concentration compared with standard. In the xanthine/xanthine oxidase system, curcumin significantly inhibited uric acid production (IC50=0.71 ± 0.06 mg/mL). Regarding antiinflammatory activity, curcumin showed significant inhibition of albumin denaturation with an IC50 value of 1181.69 ± 1.11μg/mL. Conclusion: These results indicated that curcumin showed promising antioxidant, anti-gout and antiinflammatory properties and might be used as potential, natural drugs against oxidative and inflammation- related diseases.

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