Наукові засади розвитку інституту юридичної риторики: в контексті теорії юридичної аргументації

Саме аргументація в юридичній риториці є одним із ключових компонентів, який позначається на результативності та якості юридичного дискурсу. Тому для наукового дослідження юридичної риторики як науким провідне значення має вивчення теорії юридичної аргументації, як складової загальної теорії аргументації.Именно аргументация в юридической риторике является одним из ключевых компонентов, который проявляет себя в результативности и качестве юридического дискур­са. Поэтому для научного исследования юридической риторики как науки приоритетное значение имеет изучение теории юридической аргументации, как составляющей общей теории аргументации.The argument in legal rhetoric is one of key components who prover in productivity and quality of a legal discourse. Therefore for scientific research of legal rhetoric science priority has studyind of the legal argument, as making general of the argument

The Carbonate-catalyzed Transesterification of Sunflower Oil for Biodiesel Production: in situ Monitoring and Density Functional Theory Calculations

Biodiesel has emerged as a promising alternative fuel to replace dwindling fossil-based resources, particularly in view of its added environmental merit of  reducing additional air pollution. Its specific attraction stems from the similarity of its physical properties to fossil fuel-derived diesel. Although the  production of biodiesel is a relatively straightforward process, reaction progress monitoring and product analysis require costly specialist equipment,  such as gas chromatography and mass spectrometry. In this study, we investigate the use of pH in monitoring the progress of carbonate-catalyzed  transesterification reactions. Specifically, we focus on potassium and sodium carbonates and sunflower oil. Our results are consistent with the results  obtained by other studies using different methods of monitoring. To test the generality of the method, pH measurements were also used to monitor the  progress of the potassium carbonate transesterification reaction in the presence of added water, glycerol and gamma-valerolactone (GVL). The obtained  results are as expected, with a limited amount of water increasing the transesterification rate; glycerol slowing the reaction slightly in accord with Le  Chatellier’s principles; and GVL increasing the rate due to co-solvent effects. Atomic-level insights into the adsorption mechanism of methanol and water  on the (001) surfaces of Na2CO3 and K2CO3 catalysts are provided by first-principles DFT calculations, which explain the increase in transesterification    reaction rate upon the addition of water

The carbonate-catalysed transesterification of sunflower oil for biodiesel production: in situ monitoring and density functional theory calculations

Biodiesel has emerged as a promising alternative fuel to replace dwindling fossil-based resources, particularly in view of its added environmental merit of reducing additional air pollution. Its specific attraction stems from the similarity of its physical properties to fossil fuel-derived diesel. Although the production of biodiesel is a relatively straightforward process, reaction progress monitoring and product analysis require costly specialist equipment, such as gas chromatography and mass spectrometry. In this study, we investigate the use of pH in monitoring the progress of carbonate-catalyzed transesterification reactions. Specifically, we focus on potassium and sodium carbonates and sunflower oil. Our results are consistent with the results obtained by other studies using different methods of monitoring. To test the generality of the method, pH measurements were also used to monitor the progress of the potassium carbonate transesterification reaction in the presence of added water, glycerol and gamma-valerolactone (GVL). The obtained results are as expected, with a limited amount of water increasing the transesterification rate; glycerol slowing the reaction slightly in accord with Le Chatellier's principles; and GVL increasing the rate due to co-solvent effects. Atomic-level insights into the adsorption mechanism of methanol and water on the (001) surfaces of Na2CO3 and K2CO3 catalysts are provided by first-principles DFT calculations, which explain the increase in transesterification reaction rate upon the addition of water

Adsorption and Desulfurization Mechanism of Thiophene on Layered FeS (001), (011) and (111) Surfaces : A Dispersion-Corrected Density Functional Theory Study

Layered transition metal chalcogenides have emerged as a fascinating new class of materials for catalysis. Here, we present periodic density functional theory (DFT) calculations of the adsorption of thiophene and the direct desulfurization reaction pathways on the (001), (011) and (111) surfaces of layered FeS. The fundamental aspects of the thiophene adsorption, including the initial adsorption geometries, adsorption energies, structural parameters and electronic properties are presented. From the calculated adsorption energies, we show that the flat adsorption geometries, wherein the thiophene molecule forms multiple π-bonds with the FeS surfaces are energetically more favourable than the upright adsorption geometries, with the strength adsorption decreasing in the order FeS(111) > FeS(011) > FeS(001). The adsorption of the thiophene onto the reactive (011) and (111) surfaces is shown to be characterized by charge transfer from the interacting Fe d-band to the π-system of the thiophene molecule, which causes changes of the intramolecular structure including loss of aromaticity and elongation of the C−S bonds. The thermodynamic and kinetic analysis of the elementary steps involved in the direct desulfurization of thiophene on the reactive FeS surfaces is also presented. Direct desulfurization of thiophene occurs preferentially on the (111) surface, as reflected by the overall exothermic reaction energy calculated for the process (ER = −0.15 eV), with an activation energy of 1.58 eV

Activation and dissociation of CO2 on the (001), (011), and (111) surfaces of mackinawite (FeS): A dispersion-corrected DFT study

Iron sulfide minerals, including mackinawite (FeS), are relevant in origin of life theories, due to their potential catalytic activity towards the reduction and conversion of carbon dioxide (CO2) to organic molecules, which may be applicable to the production of liquid fuels and commodity chemicals. However, the fundamental understanding of CO2 adsorption, activation, and dissociation on FeS surfaces remains incomplete. Here, we have used density functional theory calculations, corrected for long-range dispersion interactions (DFT-D2), to explore various adsorption sites and configurations for CO2 on the low-index mackinawite (001), (110), and (111) surfaces. We found that the CO2 molecule physisorbs weakly on the energetically most stable (001) surface but adsorbs relatively strongly on the (011) and (111) FeS surfaces, preferentially at Fe sites. The adsorption of the CO2 on the (011) and (111) surfaces is shown to be characterized by significant charge transfer from surface Fe species to the CO2 molecule, which causes a large structural transformation in the molecule (i.e., forming a negatively charged bent CO2 −δ species, with weaker C—O confirmed via vibrational frequency analyses). We have also analyzed the pathways for CO2 reduction to CO and O on the mackinawite (011) and (111) surfaces. CO2 dissociation is calculated to be slightly endothermic relative to the associatively adsorbed states, with relatively large activation energy barriers of 1.25 eV and 0.72 eV on the (011) and (111) surfaces, respectively

DFT-D2 simulations of water adsorption and dissociation on the low-index surfaces of mackinawite (FeS)

The adsorption and dissociation of water on mackinawite (layered FeS) surfaces were studied using dispersion-corrected density functional theory (DFT-D2) calculations. The catalytically active sites for H2O and its dissociated products on the FeS {001}, {011}, {100}, and {111} surfaces were determined, and the reaction energetics and kinetics of water dissociation were calculated using the climbing image nudged elastic band technique. Water and its dissociation products are shown to adsorb more strongly onto the least stable FeS{111} surface, which presents low-coordinated cations in the surface, and weakest onto the most stable FeS{001} surface. The adsorption energies decrease in the order FeS{111} > FeS{100} > FeS{011} > FeS{001}. Consistent with the superior reactivity of the FeS{111} surface towards water and its dissociation products, our calculated thermochemical energies and activation barriers suggest that the water dissociation reaction will take place preferentially on the FeS nanoparticle surface with the {111} orientation. These findings improve our understanding of how the different FeS surface structures and the relative stabilities dictate their reactivity towards water adsorption and dissociation

Surface and shape modification of mackinawite (FeS) nanocrystals by cysteine adsorption : a first-principles DFT-D2 study

The control of nanoparticle shape offers promise for improving catalytic activity and selectivity through optimization of the structure of the catalytically active site. Here, we have employed density functional theory calculations with a correction for the long-range interactions (DFT-D2) to investigate the effect of adsorption of the amino acid cysteine on the {001}, {011}, {100}, and {111} surfaces of mackinawite, which are commonly found in FeS nanoparticles. We have calculated the surface energies and adsorption energies for all the surfaces considered, and compared the surface energies of the pure and adsorbed systems. Based on the calculated surface energies, we have simulated the thermodynamic crystal morphology of the pure and cysteine-modified FeS nanoparticles using Wulff's construction. The strength of cysteine adsorption is found to be related to the stability of different surfaces, where it adsorbs most strongly onto the least stable FeS{111} surface via bidentate Fe–S and Fe–N chemical bonds and most weakly onto the most stable FeS{001} surface via hydrogen-bonded interactions; the adsorption energy decreases in the order {111} > {100} > {011} > {001}. We demonstrate that the stronger binding of the cysteine to the {011}, {100}, and {111} surfaces rather than to the {001} facet results in shape modulation of the FeS nanoparticles, with the reactive surfaces more expressed in the thermodynamic crystal morphology compared to the unmodified FeS crystals. Information regarding the structural parameters, electronic structures and vibrational frequency assignments of the cysteine–FeS complexes is also presented

Influence of inorganic solution components on lithium carbonate crystal growth

Lithium-bearing brines are an increasingly attractive source of Li for extraction. One extraction mechanism is the removal of Li from the fluid phase through the precipitation of zabuyelite (Li2CO¬¬3). The chemistry of the brine plays an important role in this process because ions in solution can compete for the components of the Li-carbonate phase. Here we explore the effect of different brine components on the precipitation of zabuyelite using experiments and computational simulations. Crystals formed in all solutions showed morphological evidence for potential transformation from a precursor phase. Our study indicates that Ca2+ and SO42- are incorporated into the precipitated zabuyelite crystals. Sulfate also interacts directly with specific surfaces on the growing crystal and is expected to form ion-pairs with Li+ in solution. Similarly, Na+ appears to form ion pairs in solution with the carbonate ion, slowing nucleation of zabuyelite in the experiments. K+ and Cl- may interact with the growing zabuyelite crystals, but, do not appear to affect zabuyelite nucleation and growth times. These experiments highlight the importance of understanding the solution chemistry on zabuyelite formation in order to predict the efficiency of extraction processes and the purity of the solids

Influence of inorganic solution components on lithium carbonate crystal growth

Lithium-bearing brines are an increasingly attractive source of Li for extraction. One extraction mechanism is the removal of Li from the fluid phase through the precipitation of zabuyelite (Li2CO¬¬3). The chemistry of the brine plays an important role in this process because ions in solution can compete for the components of the Li-carbonate phase. Here we explore the effect of different brine components on the precipitation of zabuyelite using experiments and computational simulations. Crystals formed in all solutions showed morphological evidence for potential transformation from a precursor phase. Our study indicates that Ca2+ and SO42- are incorporated into the precipitated zabuyelite crystals. Sulfate also interacts directly with specific surfaces on the growing crystal and is expected to form ion-pairs with Li+ in solution. Similarly, Na+ appears to form ion pairs in solution with the carbonate ion, slowing nucleation of zabuyelite in the experiments. K+ and Cl- may interact with the growing zabuyelite crystals, but, do not appear to affect zabuyelite nucleation and growth times. These experiments highlight the importance of understanding the solution chemistry on zabuyelite formation in order to predict the efficiency of extraction processes and the purity of the solids