A time-resolution study with a plastic scintillator read out by a Geiger-mode Avalanche Photodiode

In this work we attempt to establish the best time resolution attainable with a scintillation counter consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode. The measured time resolution is inversely proportional to the square root of the energy deposited in the scintillator, and scales to 18ps (sigma) at 1MeV. This result competes with the best ones reported for photomultiplier tubes.Comment: 8 pages, 8 figure

Динамика коммуникативной толерантности и принятия другого при студентов социальной работе

This article is an attempt to analyze the dynamics of development of the communicative tolerance and the acceptance of the other person in the students studying to become Social Workers as part of the traditional higher education, seen as being among the main requirements for performing an effective communication in the social work practice. Presented are results from an experimental study held in 2016-2018 with Social Work students from the Faculty of Medicine at Trakia University, Stara Zagora, Bulgaria. On the basis of these results, proven is the necessity of elaborating scientifically justified models focused on a systematic development of the students’ communicative tolerance and their level of accepting the other person, and the inclusion of these models into the higher school training programmes.Este artículo es un intento de analizar la dinámica del desarrollo de la tolerancia comunicativa y la aceptación de la otra persona en los estudiantes que estudian para convertirse en trabajadores sociales como parte de la educación superior tradicional, visto como uno de los principales requisitos para realizar una comunicación efectiva. en la práctica del trabajo social. Se presentan los resultados de un estudio experimental realizado en 2016-2018 con estudiantes de Trabajo Social de la Facultad de Medicina de la Universidad de Trakia, Stara Zagora, Bulgaria. Sobre la base de estos resultados, se demuestra la necesidad de elaborar modelos científicamente justificados centrados en un desarrollo sistemático de la tolerancia comunicativa de los estudiantes y su nivel de aceptación de la otra persona, y la inclusión de estos modelos en los programas de formación de la escuela superior.Данная статья является попыткой проанализировать динамику развития коммуникативной толерантности и принятия другого человека у студентов-будущих социальных работников, которые рассматриваются как одно из основных требований для эффективного общения в практике социальной работы. Представлены результаты экспериментального исследования, проведенного в 2016-2018 годах со студентами факультета социальной работы медицинского факультета Университета Тракия, Стара Загора, Болгария

The Influence Of Social Media On Advertising Tourism Services (In The Example Of Bulgaria)

This article aims to provide an in-depth review of current literature related to the rapid and inevitable spread of social networks as a source of information influencing consumer opinion. To achieve this, it looks at how internet platforms are becoming an invariable part of the user's daily life. The main trends showing the place and role of social networks such as advertising tools in the tourism industry are revealed. It also examines their impact on the end user, tourist preferences, how they change and comply with new understandings. Two hypotheses are put forward for proof. In the course of the research, the following scientific methods were used: analysis, synthesis, graphical and systems approach

Dinámica del comportamiento asertivo en los estudiantes – futuros trabajadores sociales

The article deals with the dynamics of assertive behavior in the Social Work students as assertiveness is one of the most important personal skills needed for the successful interaction between them and their Clients who face a difficult life situation.  The characteristics of assertiveness have been theoretically determined paying special attention to the specifics of its manifestations in the interaction between the Social Worker and the Client. On the basis of the conducted empirical study involving Social Work students, analyzed is the dynamics of their assertive behavior based on some of its main components and on their integrity as a personal quality. Considering the research results, justified is the need of including in the educational process specially elaborated programmes with a main focus on the development of assertive behavior. &nbsp

От «народов» к «архонтиям» (I) «Склавиния» и «Склавоархонтия»: понятия и хронология

This article deals with the terms ‘Sclavinia’ and ‘Sclavoarchontia’, which are used in historiography in different and even contradictory ways, and aims to clarify a highly complicated topic, investigating the ways these terms were used by contemporaries, trying to define differences between them and connecting their use with the political changes of the time. Topics discussed include the chronology of the terms’ usage, different ways in which they were being used, relations of ‘Sclavinia’ and ‘Sclavoarchontia’ with the Empire, their appearance and disappearance and the political processes connected with it, as well as the analysis of the existing interpretations. The first part mostly discusses chronology and some existing hypotheses. The second (and the main) part analyses the way these terms were used and tries to define them.The hypothesis presented connects these terms with the re-establishing of imperial authority in the Balkans, marked in the sources by replacing the term ‘Slavic nations’, which had been used until the late 8 century to denote the independent Balkan Slavic societies and their lands. The Empire lacked the capacity for direct subjugation of the independent Slavic communities and was forced to rely on complicated measures including colonization and ensuring Slav cooperation in the process. In the themes where the Empire had enough power, Slavic communities were organized as ‘Sclavoarchontias’, who received archons from the strategos, paid collective tribute and served as symahoi, but kept some inner autonomy. The Empire also tended to ensure the cooperation of Slavic communities around themes by granting titles and subsidies to some powerful Slavic leaders, which led to the creation of client states known as ‘Sclavinias’. They were not part of the thematic system, they had their native and hereditary leaders recognized and affirmed by the emperor by titles and seals and act as imperial allies. A prototype of both had appeared at the end of the 7th c., but only when relations of such types had multiplied after Stauracius’ expedition in 783, corresponding generic terms appeared and became regular. DOI: 10.31168/2305-6754.2020.9.1.1В статье рассматриваются термины «Склавиния» и «Склавоархонтия», которые употребляются в исторических источниках весьма различными, порой противоречивыми способами; предпринята попытка определить, как эти термины использовались современниками, в чем заключалось различие в их значении и насколько употребление того или другого наименования было связано с изменением политической ситуации. Соответственно, в задачу исследования входит описание появления и исчезновения этих терминов и относительной хронологии их бытования, учитывающее изменяющиеся во времени отношения с Империей тех, кто обозначались как «Sclavinias» и «Sclavoarchontias». Кроме того, в первой части работы предложен анализ существующих в науке интерпретаций соответствующих обозначений.Мы полагаем, что появление терминов «Склавиния» и «Склавоархонтия» связано с восстановлением имперской власти на Балканах, они призваны были заменить использовавшийся до конца VIII в. термин «славянские народы», обозначавший независимые славянские общины и их земли. Не имея возможности немедленно подчинить эти общины, Империя была вынуждена принять ряд сложных мер, причем процесс колонизация предполагал, по-видимому, некое добровольное сотрудничество славян. Там, где у Империи было достаточно сил, славянские общины были организованы в «Склавоархонтии», платившие коллективную дань, но сохранявшие некоторую внутреннюю автономию. С другой стороны, Империя стремилась добиться сотрудничества, предоставляя некоторым влиятельным славянским лидерам титулы и субсидии, что приводило к созданию зависимых княжеств, известных как Склавинии. Последние не входили в систему фем, при этом их местные и наследственные лидеры были признаны и утверждены императором и выступали в качестве союзников Империи. Проообраз таких двух типов отношений зародился в конце VII в., но термины Склавиния и Склавоархонтия появились и стали регулярно использоваться лишь в ту пору, когда после экспедиции Ставракия в 783 г. обе упомянутые выше политические модели стали активно тиражироваться. DOI: 10.31168/2305-6754.2020.9.1.

Nonlinear vibrations of 3D beams

This work was supported by Fundação para a Ciência e a Tecnologia, through the scholarship SFRH/BD/35821/2007Tese de doutoramento. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 201

Biocompatibility of glass-ionomer cements in dentistry

Biocompatibility takes into account the ability of a material to elicit a specific biological response after administration to a living organism. The concept does not define only one quality of the material, but reflects a complex of interactions with the biological environment in which it is placed. Over time, the definition of biocompatibility has gradually changed. Dental cements are the main clinical obturating materials. First created by Wilson and Kent in 1969, glass ionomer (polyalkenoate) cements have become widely used in medicine and dentistry.The purpose of this review is to discuss the biocompatibility of glass ionomer cements.Scientific databases - PubMed and SCOPUS were used to find appropriate studies in English on the topic of this article, with the following keywords - biocompatibility, glass ionomer cements, dentistry. A time period of 2000-2021 was set to screen articles and track the progress of the biocompatibility of dental cements in the new millennium. In addition to the cited scientific databases and articles such as clinical trials, review articles, meta-analyzes, writing of the report included information from Bulgarian and foreign textbooks in English on the subject. After applying the screening criteria, 61 results were displayed in SCOPUS and 215 in PubMed. From them, selected articles that describe experimental productions with testing the properties of cements, incl. to living cells, were reviewed.Science has found that by modifying the composition of the powder and the liquid of the cement, properties and biocompatibility can be affected. Modifications with the addition of nanoparticles hydroxylapatite and silica, carbon nanocompounds, zinc ions, cellulose microfiber and nanocrystals, amorphous calcium phosphate, chlorhexidine, collagen type 1 and peptides have been reported. Cement liquid has also been improved, which changes its properties.In the given time period between 2000-2021 there is a rapid rise of development and improvement of the properties of already synthesized cements. Efforts are being made to study the biocompatibility of materials and their properties to help tissue regeneration. There is also a wider use of materials and their implementation into various fields of medicine and dentistry