Energetic and Geometric Characteristics of Substituents, Part 3: The Case of NO2 and NH2 Groups in Their Mono-Substituted Derivatives of Six-Membered Heterocycles

Substituted heterocyclic arenes play important roles in biochemistry, catalysis, and in the design of functional materials. Exemplary six-membered heteroaromatic molecules, that differ from benzene by inclusion of one heteroatom, are pyridine, phosphorine, arsabenzene, and borabenzene. This theoretical study concerns the influence of the heteroatom present in these molecules on the properties of substituents of two types: electron-donating (ED) NH2 group and electron-accepting (EA) NO2 group, attached at the 2-, 3-, or 4-position. The effect is evaluated by the energy of interaction (Erel) between the substituent and the substituted system and electronic properties of the substituents described by the charge of the substituent active region (cSAR) index. In addition, several geometric descriptors of the substituent and heteroaromatic ring, as well as changes in the aromaticity, are considered. The latter are assessed using the Electron Density of Delocalized Bonds (EDDBs) property of delocalized π electrons. The obtained results show that the electronegativity (EN) of the heteroatom has a profound effect on the EA/ED properties of the substituents. This effect is also reflected in the geometry of studied molecules. The Erel parameter indicates that the relative stability of the molecules is highly related to the electronic interactions between the substituent and the heteroarene. This especially applies to the enhancement or weakening of π-resonance due to the EN of the heteroatom. Additionally, in the 2-heteroarene derivatives, specific through-space ortho interactions contribute to the heteroatom effects.

PROBLEMATIKA PERIKANAN PADA ZONA EKONOMI EKSKLUSIF INGGRIS DAN UNI EROPA

This research explains Brexit which leads to fisheries problems between United Kingdom (UK) and European Union (EU), regarding mechanism of methodology in distributing allocation of fishing quotas. This normative research uses statute, case, and comparative approach. The results shows that the problem between United Kingdom and European Union lies in the methodology of determining the amount of fishing quota through legal instruments established by the parties European Union wants to use relative stability model, whereas United Kingdom wants to use zonal attachment model Furthermore, the proposed form of solution that can be used in an effort to solve the fisheries problem between the United Kingdom and the European Union are thorugh one or more variation of zonal attachment, historical attachment, relative stability, or other mechanism (Hannesson Model).

Towards a Cognitively Based Quantification of Metrical Dissonance

Metrical dissonance is a powerful tool for creating and manipulating musical tension. The relative extent of tension can be more or less acute depending (in part) on the type of dissonance used and moving among those dissonance types can contribute to the shape of a musical work. This chapter sets out a model for quantifying relative dissonance that incorporates experimentally substantiated principles of cognitive science. A supplementary webpage [**html page] provides an interactive guide for testing out these ideas, and a further online supplement [**URL—included in the main text as Section \ref{sec:online}] provides mathematical formalizations for the principles discussed. We begin with a basic model of metre where a metrical position’s weight is given simply by the number of pulse levels coinciding there. This alone enables a telling categorization of displacement dissonances for simple metres and a first sense of the relative differences between them. These arbitrary weighting ‘values’ are then refined on the basis of tempo and pulse salience. This provides a more subtle set of gradations that reflect the cognitive experience of metre somewhat better while still retaining a clear sense of the simple principles that govern relative dissonance. Additionally, this chapter sees the model applied in a brief, illustrative analysis and in a preliminary extension to ‘mixed’ metres (5s, 7s,…). This sheds light on known problems such as the relative stability of mixed metres in different rotations, and suggests a new way of thinking about mixed metres’ relative susceptibility to metrical dissonance.

A Database of Low-Energy Atomically Precise Nanoclusters

The chemical and structural properties of atomically precise nanoclusters are of great interest in numerous applications, but the structures of the clusters can be computationally expensive to predict. In this work, we present the largest database of cluster structures and properties determined using ab-initio methods to date. We report the methodologies used to discover low-energy clusters as well as the energies, relaxed structures, and physical properties (such as relative stability, HOMO-LUMO gap among others) for over 50,000 clusters across 55 elements. We have identified 589 structures which have energies lower than any previously reported in the literature by at least 1 meV/atom, and we have identified 1340 new structures for clusters that were previously unexplored in the literature. Patterns in the data reveal insights into the chemical and structural relationships among the elements at the nanoscale. We describe how the database can be accessed for future studies and the development of nanocluster-based technologies.

Acceleration of alkyne metathesis in multicomponent catalytic systems by use of alternative Mo(0) sources under optimised conditions

Alkyne metathesis in multicomponent catalytic systems, although subject to changes, is still a domain of molybdenum hexacarbonyl as a source of Mo(0). Our findings show that this coordination compound is relatively inert under metathesis conditions, which results in noticeably long induction of catalytic activity, and the kinetics of this transformation can greatly benefit from switching to more labile Mo(0) complexes. Several easily obtainable ones had been tested and [Mo(CO)3(py)3] has been chosen as the one exhibiting the most desired features, i.e. nearly instant catalytic activity and relative stability in the air.

Formation of indicators of sustainable development for the resource region: the Amur ecoregion

The article discusses the formation and practical use of indicators for assessing the sustainability of development at the regional level. Using the example of the Amur ecoregion, we study the dynamics of some economic, social and environmental indicators in 2013-2019, their compliance with the objectives of the state policy for the accelerated development of the Far Eastern Federal District. It is shown that the result of the action of preferential regimes was the growth of resource industries in the structure of the economy of the Amur ecoregion. A certain decrease in the parameters of sustainability according to social indicators was revealed with positive dynamics of economic and relative stability of environmental indicators in the Amur ecoregion. The relevance and scientific significance of the development of methodological and methodological support for assessing socio-ecological-economic sustainability and the formation of its indicators for the regional level was confirmed.

Design of a High-precision 5V/10V DC Voltage Reference Source

This paper introduces a self-developed DC voltage source, which uses the Zener reference LTZ1000 as the voltage reference element. Selecting high precise resistors and using appropriate measures to insulate and isolate, the short—time relative stability of 7V output voltage provided by LTZ1000 is 1.5×10-8. The voltage of 10V is increased up by a network, composed by high precise resistors with the same temperature coefficient, and its short—time relative stability is 2.2×10-8. The voltage of 5V is divided by a network, composed by high precise resistors with the same temperature coefficient, and its short—time relative stability is 3.6×10-7. The circuit is suitable for signal acquisition, voltage calibration and other applications.

О НЕКИМ ОРТОГРАФСКИМ ОДЛИКАМА ПИСАНЕ ГРАЂЕ ИЗ 19. ВИЈЕКА (ИЛУСТРАЦИЈЕ И КОМЕНТАРИ) / ON SOME ORTHOGRAPHIC CHARACTERISTICS OF THE WRITTEN MATERIAL FROM THE 19TH CENTURY (ILLUSTRATIONS AND COMMENTS)

One hundred and seventy years after the death of Petar II Petrovic Njegos, and one hundred and ninety years since he was elected as the head of the Montenegrin state, and, therefore, since the establishment of the Montenegrin Senate, are all the reasons and an important occasion for returning to the written material of the Montenegrin Senate in this paper. The paper is part of a broader linguistic analysis of the documentation of the central and highest state authority in 19th -century Montenegro. It represents an orthographic analysis of the original documents of the Montenegrin Senate (formed at the beginning of the rule of Njegos – 1831) – both as the addresser and the addressee. Specifically, we followed the written reflection of consonant contacts at the morpheme boundaries within words, as well as consonant contacts at the junctions of individual words. Given the number of correspondents of the epistolary communication of the Montenegrin Senate, our analysis reveals the segments of collective orthographic practice from that period in Montenegro. The conclusions about the collective orthographic practice of one period are based on the process of monitoring the spelling procedures of individuals of different literacy levels. In spite of their limitations and, therefore, the limitations of the analysis, it provided the material that helped us discern a collective orthographic trait – a considerable inconsistency in the orthography of consonant groups at the morpheme boundaries within words and relative stability in their orthography at the junction of individual words: in the orthography of consonant groups at the morpheme boundaries within words, two ways of writing are dominant – morphological and phonological, while in the orthography of consonant groups at the junctions of separate words, the morphological principle is mostly established. The same type of orthographic instability was mainly characteristic of the literary expression of the 19th century. This is observable in the comparison of the recorded situation with the data about the orthography of Njegos and with the data on the orthographic procedures of other writers of the time in Montenegro.