Functionalized hyperbranched polymers via olefin metathesis

Hyperbranched polymers are highly branched, three-dimensional macromolecules which are closely related to dendrimers and are typically prepared via a one-pot polycondensation of AB_(n≥2) monomers.^1 Although hyperbranched macromolecules lack the uniformity of monodisperse dendrimers, they still possess many attractive dendritic features such as good solubility, low solution viscosity, globular structure, and multiple end groups.^1-3 Furthermore, the usually inexpensive, one-pot synthesis of these polymers makes them particularly desirable candidates for bulk-material and specialty applications. Toward this end, hyperbranched polymers have been investigated as both rheology-modifying additives to conventional polymers and as substrate-carrying supports or multifunctional macroinitiators, where a large number of functional sites within a compact space becomes beneficial

Prevalence of suicidal behaviours and its correlates in Latvian general population : 2019-2020

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The results of PHQ-9 screening of Latvian general population in 2019-2020

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Study of Posting Activities of Russian Users on Social Media

Content marketing on social media depends on trends in consumer behaviors. A changing focus and emphasis on audience activities on social media are a key optimization problem in social media marketing (SMM). A solution to this problem lies in a field of ongoing empirical studies of posting frequency. In the review of the literature, authors highlight the role of social media as a promising channel for a direct interaction of companies/brands with consumers. Based on theoretical generalizations, authors present a generation sequence of an SMM content strategy. The article also includes an analysis of posting activities of users from Russia on well-known social media. A cost-benefit analysis of posting activities rests upon some factors: socio-demographic characteristics of users, a content format, time and day of the week parameters, etc. Data come from such sources as aggregated statistics of social media and selective interviewing. An analysis of activities for users from Russia has shown that VKontakte is the most popular platform; Instagram is the second, while Facebook is the third. Odnoklassniki and Twitter are less preferred. VKontakte users respond best to short posts. On Facebook, entries with medium-sized texts have got the highest number of responds. On Instagram, long posts work better. The photo format is a leader in all of the social media. The video format has a middle position, while a text is the most inefficient type of content. There is strong differentiation in response time depending on a target audience. Findings have made it possible to present recommendations for optimization of content marketing

Role of Russia in peaceful settlement of the conflict of North and South Korea: event analysis

This study analyzes the conflict between North Korea and South Korea. The Russian Federation has played an important role in the peaceful settlement of this conflict, which has an impact on the formation of the appearance of Russia in the international arena. The theoretical basis of the study was the theory of images, communication and international conflicts. Using the eventanalysis method, an event-based picture of the conflict was built, comparative assessments were made, conflicting parties, indirect participants and intermediaries were identified. An analysis of the current situation is given, groups of interests and the role of Russia in the peaceful settlement of this conflict are identified.Este estudio analiza el conflicto entre Corea del Norte y Corea del Sur. La Federación de Rusia ha desempeñado un papel importante en la solución pacífica de este conflicto, que tiene un impacto en la formación de la aparición de Rusia en la arena internacional. La base teórica del estudio fue la teoría de las imágenes, la comunicación y los conflictos internacionales. Utilizando el método de análisis de eventos, se construyó una imagen del conflicto basada en eventos, se realizaron evaluaciones comparativas, se identificaron las partes en conflicto, los participantes indirectos y los intermediarios. Se presenta un análisis de la situación actual, se identifican los grupos de intereses y el papel de Rusia en la solución pacífica de este conflicto.Este estudo analisa o conflito entre a Coréia do Norte e a Coréia do Sul. A Federação Russa tem desempenhado um papel importante na solução pacífica deste conflito, que tem um impacto sobre a formação da aparição da Rússia na arena internacional. A base teórica do estudo foi a teoria das imagens, comunicação e conflitos internacionais. Usando o método de análise de eventos, uma imagem baseada em eventos do conflito foi construída, avaliações comparativas foram feitas, partes conflitantes, participantes indiretos e intermediários foram identificados. Uma análise da situação atual é dada, grupos de interesses e o papel da Rússia na solução pacífica deste conflito são identificados

The Effect of Digital Economy and Artificial Intelligence on The Participants of The School Educational Process

The article examines the nature of the effect of the digital economy and artificial intelligence on the participants of the school educational process. The study deploys a Likert scale questionnaire, focused interview, and IBM SPSS Statistics 22 as the main instruments. The authors determine the status of a teacher in the AI-teacher system and identify the nature of AI’s influence on the students and communication within the teacher-student-teacher system. Support is provided for the hypothesis suggesting that the effect of the digital economy and AI on the participants of the school educational process (teachers and students) is complex and controversial and causes the differences in the teachers’ positions depending on their age, working experience, and the subject of specialization. The primary advantage of the article is the identification of stable relationships in the teacher-student-teacher system developing with the help of AI. The study indicates the teacher’s advantage over AI in teaching technique and social influence, as well as the negative effect of AI on students’ health. For the first time, the authors examine the nature of role changes in the AI-teacher system in the context of a global pandemic. The danger of AI replacing teachers with the help of teachers themselves is identified. The acquired results may be used by theorists and practitioners for further development of the foundations of the system of education and human interaction with AI in the digital economy

Dynamics of Switching Waves in a Nanofluid in a Light Field

The dynamics of the concentration of nanofluids placed in a light field with a Gaussian intensity profile is studied theoretically. The investigation is based on the analytical and numerical solutions of the system of linearized heat conduction and convectiondiffusion equations. The convection-diffusion equation contains terms that correspond both to the Soret effect and to the transfer of nanoparticles, caused by the action of a light field on them (electrostriction). The dependence of the coefficient of thermal conductivity of the medium on the concentration is taken into account. It is shown that under these conditions single travelling waves appear in the medium, the velocity of which depends not only on the thermal physical parameters of the medium, but also on the polarization of the particles. Conditions under which the stratification of the medium is possible are found

Contents of heavy metals in fructicose epiphytic lichens of Karelia as indicator of atmospheric transport of pollutants

Results of studies of heavy metals contents in fruticose epiphytic lichens in Karelia are presented and the influence of different sources on the elemental composition of lichens has been estimated. It has been shown, that long-range atmospheric transport influences strongly the accumulation of Pb, Zn, Cd, Sb. For Al, Fe and Co lithogenic source is the main one. In the Northern Karelia atmospheric transport of Cu, Co and Ni from metallurgic enterprises of the Murmansk Region is important source of these elements