bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment outcome in patients with acute ST elevation myocardial infarction where more than 12 hours and less than 48 hours have passed from the onset of symptoms
Authors: Ivanović Vladimir , Grgur Jelena , Dabović Dragana , Petrović Milovan , Stojšić-Milosavljević Anastazija , Bjelobrk Marija , Čanković Milenko , Stevanović Maja
Published: December 2020

Introduction/Objective Patients who have had symptoms for more than 12h before receiving treatment are considered to be myocardial infarction late presenters. The literature contains scarce and often controversial data about treating such patients. The objective of the paper is to present treatment outcome in patients with acute ST-elevation myocardial infarction (STEMI), whose therapy was initiated more than 12h and less than 48 hours after the onset of symptoms. Methods the research included 130 patients who had suffered from acute STEMI in 2017, all of whom presented more than 12h and less than 48h after the onset of symptoms. A primary percutaneous coronary intervention (PPCI) was used to treat 109 patients, while 21 patients were treated conservatively. An analysis was performed correlating treatment results, intrahospital mortality, one-year survival rate depending on the type of treatment, risk factors and comorbidity. Results A statistically significant difference (x 2 =7,119; p=0,017) has been verified when comparing the mortality of STEMI patients treated with PPCI(8.3%) and those treated conservatively (28.6%). A statistically significant difference (t=9,385; p=0,005) has been verified when it came to treating STEMI patients that were also suffering from diabetes. In the group treated with PPCI, 77.8% of the patients that had died had diabetes. No comorbidity showed a statistically significant difference in distribution depending on the type of treatment and treatment results. Conclusion When deciding on the type of treatment these patients shall receive, the following should be taken into consideration: clinical presentation, hemodynamic status and presence of life-threatening arrhythmias. There is still no clear guideline for treating such patients.
Personal experience and how informed adolescents are regarding contraception
Authors: Savić Nikola , Avramović Bojana , Jokić Zoran , Anđelić Slađana , Bogdanović-Vasić Slobodanka
Published: December 2020

Introduction Contraception is the most favourable method of family planning. Prevention of unwanted pregnancy has great significance, both as a measure of health preservation and as a wider preventive and social measure. Objective to evaluate how informed the adolescents are when it comes to contraception, as well as to evaluate their personal experiences. Methods the research was conducted in the form of a cross-sectional study. The research instrument was a questionnaire the adolescents were asked to fill, which contained questions constructed to assess how well they were informed about the importance of contraception as well as their personal experiences. The study included 120 students and the sample was intentional, as the study was conducted at the Faculty of Health and Business Studies in Valjevo, Singidunum University in April-May 2019. The participation in the study was voluntary and anonymous, and the research was approved by the authorities of the institution. Results the results were analysed using descriptive statistical methods. The respondents were between 19 and 23 years of age and predominantly female (83%), while only 17% were male. The majority of the respondents were well informed on the subject of mechanical contraception methods and the use of condoms. The condom was the most commonly used method of contraception during sexual intercourse (63%). A large number of respondents (40%) believed that adolescents could do with more information on the subject. Conclusion the research results indicate that there is a need for more education on the subject of the importance and methods of contraception. It is necessary to intensify health education in cooperation with health institutions, schools, higher education institutions and the entire community. This need is felt by the adolescents themselves, who believe that their peers do not know enough about contraception.
Induced pluripotent Stem Cells: Where we are currently?
Authors: Rančić Nemanja , Raščanin Sanja , Miljković Milijana , Jovanović Mirjana
Published: December 2020

Induced Pluripotent Stem Cells (iPSCs) are a type of pluripotent stem cells generated by reprogramming an adult somatic cell genome to the stage of a pluripotent stem cell in vitro by inducing a forced expression of specific transcription factors that are important for the maintenance of pluripotency. The iPSCs seem to be very similar to Embryonic Stem Cells (ESCs) in terms of morphology, cell surface markers and gene expression levels, but recent studies have demonstrated some differences between the two cell types. However, iPSCs might have potential application in regenerative medicine, transplantation, drug testing, disease modelling, and avoidance of tissue rejection and with less ethical concern than ESCs. This paper aims to present the most important characteristics of iPSCs which have therapeutic significance.
Potential of different Xanthomonas campestris strains for xanthan biosynthesis on waste glycerol from biodiesel production
Authors: Rončević Zorana , Zahović Ida , Danilović Nikolina , Dodić Siniša , Grahovac Jovana , Dodić Jelena
Published: December 2020

A rapid expansion of the biodiesel industry has created various ecological issues relative to crude glycerol disposal. Xanthan biosynthesis is considered one of the sustainable solutions for minimizing the adverse effects of waste crude glycerol on the environment. The initial phase of xanthan production on crude glycerol entails the screening of producing microorganism. Therefore, the purpose of this study is to examine the possibility of xanthan production on a crude glycerol-based medium using different Xanthomonas campestris strains. The bioprocesses performed were assessed according to the rheology of the media considered, amounts of xanthan produced and conversion degrees of the most important nutrients present. The pseudoplastic behavior of all the media considered, the amounts of xanthan produced (5.22-7.67 g/L) and the degrees of crude glycerol, total nitrogen and phosphorus conversion (34.44-57.61 %, 23.04-30.35 % and 18.20-22.28 %, respectively) suggest that crude glycerol, after additional bioprocess optimization, can be a suitable raw material for the industrial production of xanthan.
Film locations as perilous realms of memory: Tourists negotiating mental, virtual and real topographies of Tolkien's Middle-earth
Authors: Lukić Mina
Published: December 2020

This paper examines film locations as places of memory (les lieux de mémoire) and their role in individual imagination. Film-induced tourism creates specific sites of memory typical of global popular culture; the places of confrontation, negotiation, and interplay between fiction and reality which affect our mental as well as the real topographies. The aim is to analyse how memorised film images determine visitors ' experience of real places and their imagining of J.R.R. Tolkien's fictional world, and vice versa. The film adaptations of Tolkien's "the Lord of the Rings" and "the Hobbit", directed by Peter Jackson, were shot in New Zealand, causing it to become touristically promoted and visited as "the home of Middle-earth" and "Middle-earth on Earth". This case is analysed as an illustrative example of the aforementioned processes.
Imaginary protagonists in idiomatic expressions of the contemporary Italian language
Authors: Blatešić Aleksandra
Published: December 2020

The aim of this paper is to present imaginary personalities from oral and written literature who have found their place in Italian fixed expressions due to their character, specific circumstances, events or the things they have done or said. Most of the analysed characters in this paper are fictional, while some are associated with the most diverse stories and legends, mostly of unclear origin. If the analysed characters have been taken from a literary work, their creator is an individual and therefore a known subject. The creator of these characters can also be a collective author, and therefore an unknown subject. The characteristics of the protagonists in folk fiction and folklore have been created for a long time and they have been constantly attributed new meanings and language varieties. Although the subject of research in this paper are phrases of the contemporary Italian language, when it comes to these language forms, we cannot talk about contemporaneity in a narrower sense. Namely, due to their stability, these expressions represent a kind of antiquity, passed down from generation to generation through time and space. We will consider as contemporary those idioms which are recognizable in form and meaning in the language and speech of the XX and XXI century, and we will extract them from general and phraseological dictionaries and collections.
Medieval libraries in present-day Vojvodina
Authors: Stojkovski Boris
Published: December 2020

Throughout history, the region of present-day northern Serbian province of Vojvodina has been a crossroads of cultures and civilizations. In this context, one can observe the history of medieval libraries. In this period of time, some sources have documented the existence of a library in a very famous and rich Cistercian monastery in Petrovaradin. This was one of the most prominent convents in medieval Hungary and even Rodrigo Borgia was trying to obtain the incomes of this abbey by becoming its governor. There is an inventory of this monastery dating back to 1495 where many liturgical books are listed. The city and the fortress of Bač were a centre of renaissance in the medieval Southern Hungary, thanks to the work of the archbishop Peter Varadi. What has remained of his library shows that he has read classical Greek and Roman authors, patristic texts, Byzantine writers and so on. Finally, in the monastery of Krušedol, built in 1508, the Serbs who fled to Hungary had their first large-scale cultural and spiritual centre, with a vast library from which several valuable manuscripts have survived.
Others in heritology: The example of the 'Banat house'
Authors: Kolundžija Jovana
Published: December 2020

The museum is a permanent, non-profit institution in the service of society and its development, open to the public. It collects, preserves, researches, communicates and exhibits material testimonies of man and his environment, for the purpose of study, education and entertainment. In recent times, museums are primarily communication centres that retain and develop all other functions of a traditional museum. The main form of communication is an exhibition, although any transmission of information is considered as communication. However, the museum is not the only institution where objects of this purpose can be found. Namely, there are many alternative types of collecting and storing things from the past, although not enough attention has been paid to them or real significance attributed. A true collector is a special type of collector, their purpose being to put together a collection of related items as complete, unique and as representative as possible. A collector is a person who is passionate about collecting specific items for his own pleasure. There are a large number of people like this, because in fact it is very difficult to think of any object that nobody would collect. Some of the typical examples vary from the collectors of works of art and precious vases, to the collectors of the most ordinary, trivial, useless, discarded items that are searched for in attics and basements, sometimes even in the landfills... In search of at least one such unusual collector, I came across a small heritage museum created based on geographical affiliation: the objects collected in this collection are all representative of the past of Banat.
Ludology and narratology: Legend about the battle
Authors: Mitrović Biljana
Published: December 2020

The paper provides an overview and an analysis of the narratological and ludological approach to the study of video games and a review of the establishment of the fledgling field of game studies. The starting points of both theoretical positions, derived from the same literary theoretical corpus, are presented. The state of this discipline and the academic tensions in this field also indicate the ways in which academic community functions, as well as the mechanisms of their division or complication in the organizational and methodological plan. The ludological approach, which reduces the study of video games to the description and classification of rules and game mechanics, is regarded as reductionist, but also useful and applicable for understanding the specifics of video games. It is concluded that ludology, together with narratology and other academic disciplines in the field of humanities, forms a complete corpus of video game studies.
To be or not to be: Shakespeare and video games
Authors: Alidini Stefan
Published: December 2020

The paper analyses video games in the context of new media and considers their artistic potential from the perspective of Game Studies. Using to Be or Not to Be, an adaptation of Shakespeare's Hamlet as an example, the paper presents a theoretical examination of the game's structural, textual and narrative features and ludic elements, so as to elucidate the principles of adaptation and transformation of a literary text into a new digital form, as well as the advantages and the disadvantages of such processes. Trust in the narrative, along with adequate game mechanics and the player's perception have proven to be crucial for accomplishing intention of the game. At the same time, the analysis serves as a basis for interpretive framework that would lead to affirming the aesthetic potential of video games and thus give rise to uncovering the artistic potential of other algorithmic structures.
Bequests with a special review of The Heritage House-Belgrade
Authors: Prnjat Dejana
Published: December 2020

Taking care of a country's cultural legacy is the priority of each nation's cultural policy. The most important is its protection, since lost legacy cannot be compensated. However, research is also very important as is its presentation to the public. On the one hand, it is not surprising that allocations for culture in a poor country are minimized. On the other hand, there are many unsolved problems that do not depend on finances, like legal regulations in this domain. In this research we are going to pay special attention to the bequests of The Heritage House-Belgrade, whose founder is the City of Belgrade, since it is a unique state institution whose main activity is related to heritage and legacy.
Valorization of territorial capital in function of rural tourism development: A case study of Kneževo municipality
Authors: Rokvić-Knežić Gordana , Kalabić Milana , Vaško Željko
Published: December 2020

The main goal of the research presented in the paper is to analyse the current state and level of development of rural area, in Kneževo municipality, as well as to define the possibilities of development of certain forms of rural tourism based on the territorial capital. In other words, the capital of space consists of natural and created capital. For the purposes of the valorisation of tourist potentials, the qualitative-quantitative methodology of the World Tourism Organization was used, which includes conducting a survey using standard forms of a questionnaire. Based on this survey, resource scoring was performed according to all external and internal factors, i.e. criteria. According to the results of the research, the indicator of tourist value for Kneževo municipality is estimated with 98.74 points out of a possible 400 points, or 25% of its potential tourist value.
Employer brand and workforce performance in hotel companies
Authors: Ognjanović Jasmina
Published: December 2020

Employer brand represents an intangible asset which is the result of successful implementation of employer branding strategy that promotes the company as exceptional employer, provides the candidates with realistic expectations and fulfills the promises made to all employees. The main aim of the research is to prove that hotel companies should be strongly encouraged to develop employer brand, since this is one of the best ways to increase workforce performance. In terms of business operations, employer brand is monitored by means of appropriate dimensions (training and development, employer reputation, work/life balance, corporate social responsibility, business culture). Testing of research hypotheses was performed using regression analysis and ANOVA test. Results indicate statistically significant impact of employer brand on workforce performance and statistically significant difference in the level of accomplished average workforce performance among different category hotels.
Strategic approach to the development of ecotourism in Bor District, Serbia
Authors: Voza Danijela , Fedajev Aleksandra
Published: December 2020

The increase in ecotourism popularity at a global level is a consequence of the increased human concern for the state of natural resources. This type of alternative tourism is increasingly present in tourist trends around the world. For developing countries, ecotourism can be an opportunity for accelerating economic development by exploiting natural resources, without changing their original state. Although it offers great opportunities, the management of tourism in protected or unprotected natural assets is a great challenge. The importance of integrating the actions of all stakeholders and the usage of strategic approach are often neglected. The aim of this paper is to generate strategies for the development of ecotourism in Bor and its surroundings. For this purpose, a combined SWOT-TOWS methodology is applied. Based on the obtained results, nine strategies are proposed, whose implementation would enable the usage of natural and cultural and historical potentials for the revival of ecotourism in this area.
The role and importance of dealers (sellers) for the automobile market in Serbia
Authors: Jelenković Sanja , Brzaković Aleksandar , Mihailović Branko
Published: December 2020

Cars are the most sophisticated mass-produced products and are the result of years of research and development. Due to this nature, the technological development of cars is, in general, unpredictable. Even when they meet expectations, consumer acceptance varies from one market to the next. Consumer markets consist of customers who want to spend or benefit from a purchased product and who do not buy the product for profit, as the main goal, but to meet their needs. The role of dealers in the automotive industry is of increasing importance to both production volume and car models. Without their presence, there is the question of product placement, product pricing, and marketing activities. The strategy of the manufacturer or dealer himself is of the utmost importance, as the company creates value and how it achieves a competitive advantage, while the cost advantage sources depend on the structure of the given industry. Also crucial for the auto industry is the supply chain of spare parts. Price is a strategic and tactical variable that influences sales volume.
Economic impact of the coronavirus pandemic on the automobile industry
Authors: Radić Nikola , Radić Vlado , Stevanović Mirjana
Published: December 2020

The economic impact of the coronavirus pandemic is evident in many sectors, from service to manufacturing, leading to a synchronized shutdown of an industry not seen since World War II. The pandemic has enormous social, economic and political consequences. It will undoubtedly be marked as a watershed moment in modern history and will cause a change in the lifestyle we have known for the last few decades. In addition to being one of the greatest crises in our civilization in shock, scale and depth, the pandemic has caused many problems for vehicle manufacturers. Broken supply chains, cessation of production, shutting down factories, layoffs and declining interest and customer demand are circumstances that are driving the automotive industry into a deeper recession. The aim of the paper is to point out the consequences that the coronavirus pandemic will have on the automotive sector, as well as to identify the deficiencies of the planning system, the lack of risk management and emergency management by analyzing the basic elements o f the supply chain.
Assessment of composting processes in an automated aerobic fermentation system based on key parameters
Authors: Magyar Tamas , Mayes Rebecca , Nagy Peter
Published: December 2020

The poultry (broiler) industry is continuously increasing all over the world, therefore, the amount of waste generated in these facilities is also increasing. As a consequence of the above mentioned, the more efficient conversion of chicken manure to organic fertilizer is a key problem. The aims of the study are to investigate the changes in temperature and moisture content during composting of chicken manure in the oval tank fermentation system and to create a model for the evaluation of the performance of biodegradation processes. The moisture and temperature distribution models of the oval tank were created in Hydrus software. The results showed that the oval tank fermenter can be divided into two main zones. In the first zone, where the rate of biodegradation was relatively high, a heterogeneous temperature zone was found with continuously decreasing moisture content. The second zone was more homogenous in both temperature and moisture content. This stage represents the weak fermentation part of the technology and results in an elongated post fermentation section. Furthermore, statistically significant correlations were found between composting key parameters, such as ammonium content with temperature and organic matter content with organic nitrogen content. It was also concluded that the exact location of the manure turning and chopping mechanical system (MTCM) used for aeration had a high effect on the composting processes, as well as on the quality parameters of the mature compost.
Determination of circularity indicators: A case study of MB International Company
Authors: Pavlović Angelina , Bošković Goran , Jovičić Nebojša , Nestić Snežana , Sliusar Natalia , Stanisavljević Nemanja
Published: December 2020

The circular economy (CE) is currently a worldwide popular concept that should ensure sustainable development and resource efficiency. It is established on the theory of consumption and use of resources in the process of production in a way that affects a limitation of adverse effects on the environment. Simultaneously, this concept creates additional value and reuse of the products. In the Republic of Serbia (RS), the idea of CE is still new and underdeveloped. Hence, this paper aims to explore the possibility of implementing a CE in companies that operate in the RS by adopting the already developed methodology in the European Union. This research was conducted by monitoring the production process in the company "MB INTERNACIONAL" that produced cardboard packaging. The obtained approximate value of Circular Indicator of this company was 0.47, which indicated that the company had excellent chances for full implementation of the CE model in the business with the application of specific measures. The low-budget and highbudget measures, which could improve the circularity level in the analyzed company, are also presented in the research.
Analysis of application of aquaponic system as a model of the circular economy: A review
Authors: Aleksić Natalija , Šušteršič Vanja
Published: December 2020

In a time of limited water resources, climate change, and significant reductions in fish and plant species, aquaponics systems can play an important role in the future of ecologically and socio-economically sustainable smart cities. The paper aims to investigate the available literature that deals with the topic and current situation related to aquaponics systems - their application, effects of work, perspectives, and shortcomings, as a model of the circular economy. The exploratory method includes a literature review and the analysis of interviews with the pioneers in aquaponics in the Republic of Serbia. The main criterion for reviewing the literature was to find successful examples of aquaponics in the world and the Republic of Serbia. The result of the research is that aquaponics systems, due to the circular way of production, can be included as the model of the circular economy. Among a growing number of aquaponics pioneers, BIGH Farm, ECF Farmsystems, Urban Farmers, Bioaqua Farm, Tilamur, and Water garden currently have a successful implementation of the circular economy. These firms produce food with no waste production, they minimize energy input, and have a positive environmental impact, which are the main aims of the circular economy.
Christlikeness of Saint Sava's pedagogy
Authors: Mihajlović Tatjana , Ilić Mile
Published: December 2020

Among the Serb people, Saint Sava was an educator, the teacher of everything in life. The authors believe that one can speak of the pedagogy of Saint Sava on the condition that the term of pedagogy is understood in its broader sense, rather than as a technical and modern term for a scientific discipline. However, any pedagogy, in its broader sense, relies on the understanding of the human essence, human life, world in which a human being lives. Saint Sava can then be justifiably viewed as a pedagogue in the sense of the contemporary rationalist educator. The primary and secondary sources of study explicitly show that Saint Sava was destined to take, through historical eras, upon himself the "deposits" of ideas, thoughts, beliefs revealing underneath, irrespective of the influences, a genuine saint, the educator of his country and his people. Sava's escape to the monastery meant his departure to the spiritual discipline, asceticism, solitary world from the realm of which comes light, brought about by laborious and strenuous exploits thanks to the Christ-like lifestyle. Terminologically, the word Christlikeness implies a human being as a genuine Christ-like being, Christlikeness of the soul, sanctity and inviolability of his personality that Saint Sava pursued. The pedagogy of Saint Sava has the characteristics of Christlikeness, which is reflected in the directly or indirectly formulated objective of the education of a human being-orthodox believer that possesses, and nurtures, Christ-like qualities. The paper includes the main characteristics of the Saint Sava's pedagogy that seeks its own essence in endlessly moving closer to sanctity through efforts, exploits, co-limitations, prayerful moods, and belief in eternal life, or, in a word, through the Christ-like lifestyle, and thereby also education of children, young, and adults in the spirit of deification and orthodox Saint-Sava-like enlightenment. From the futurological point of view, the goal of the Orthodox pedagogy for Saint Sava included an optimal implementation of implicit educational and functional tasks with the desire to nurture, through education, the traits such as philanthropy, sense of justice, truthfulness, patriotism, and the love of Christ that are almost disappearing in our era.
The notion of a woman in the work of Stefan the First-Crowned
Authors: Đekić Đorđe , Zarković Božidar
Published: December 2020

The most frequently mentioned woman in the literary work of Stefan the First-Crowned is the Blessed Virgin, a God pleasing role model whose pursuit leads to the salvation of the soul. She was also a role model to his father, Stefan Nemanja. In addition, she was at the same time the most common example of a role model of mother followed by all mothers, as well as his mother Ana and his grandmother. His father's mother was mentioned but remained nameless. Of the other roles of a woman, in the centre of his attention was the wife of a husband. The context in which he mentioned her was the matrimonial law-penalties for unlawful marriage, unlawful dissolution of marriage, an adulterous woman, and forbidden marriage with sister-in-law. However, no mention was made of the obligations of parents, of a mother towards children, or of the adult children towards mothers. It must be noted that he did not talk much about a woman as a mother, though he did provide some information. It was fragmentary information about the mother-in-law, the widow, but there is no information about a woman-sister, woman-daughter, which is a striking testimony that he was not interested in these aspects of a woman. Apparently, he was only interested in a woman as a God-pleasing role model, among other things, God-pleasing mothers also in the sense of regulating marital relations.
Isa Boljetinac and young Turk regime
Authors: Zarković Vesna
Published: December 2020

At the beginning of the 20th century, the Ottoman Empire started weakening largely. This weakening was influenced by difficult economic situation accompanied by stronger diplomatic activities of the European powers. Wishing to save the state from the collapse, the Young Turk movement had forced the Sultan Abdul Hamid to concession, which led to changes on the throne. The Young Turks reinforced their activity in all parts of the Ottoman Empire and many great plans lied ahead, which had foreseen reform of the state and society including internal consolidation of the country as well. The Young Turk regime representatives propagated the idea of equality of all people, which would have the same rights and duties as well. The ideas and work of the Young Turks came across a resistance of some Albanian leaders, among which was Isa Boljetinac, known as per his crimes over Serbian population of Mitrovica casa. He was known as an influential man and he enlarged his activity out of this territory, which often served, after numerous conflicts with Turkish authorities, as the hideout. As the prominent opponent of the Young Turk regime, the conflict with authorities and Albanian movements, which marked that time, was experienced as the struggle for old privileges such as: carrying of arms, non-paying of taxes, non-interference of Turkish authorities into their relationships and, especially, non-service in the army. Determination to persist in the struggle for the return of privileges led Isa Boljetinac to get in touch with the consul of the Kingdom of Serbia in Priština, from whom he requested arms, munitions, and money. Consul thought that the fulfilment of his requests had influenced the improvement of the position of Serbs and eventually some subsequent support so that he had approved of them. Nevertheless, before the outbreak of the Balkan Wars, Isa was not clear in his answers and it was evident it could not be counted on his alliance.
TOPICAL ASPECTS OF FORMING ECOLOGICAL CULTURE AT THE MODERN STAGE
Authors:   International institute of Design and Service, Degterenko A.N.
Published: December 2020

A nowadays topical issue of the interactions between man, society and nature, reflected in the system of scientific knowledge of the new concepts and terms, with the content focus to make human development global, promoting the change of his moral values and orientations, is discussed. It is stressed that the importance of the above problem increases in the conditions, when world community is in transit to ‘green economy’, the key aspects of it being maximum rationalization of natural resources utilization and creating harmony between economy, social policy and ecology. It is assumed, that to correspond to the tendencies in the global community, the system of Russian education must have a niche to account for the potential global changes. It is noted that the topicality of forming ecological culture of specialists in the system of professional education increases after a number of federal and regional laws have been passed within the last decade. It is noted, that some Russian scientific pedagogical researches disclosed theoretical and practical aspects of forming the ecological culture in detail, including ecological education and upbringing, methods of diagnosing and forming ecological culture, problems the connections between ecology and educational environment and formation anfd development of students’ ecological outlook.
Chaos-control and parallel queue synchronization of laser local area network
Authors: Yan Sen-Lin ,   School of Electronic Engineering, Nanjing Xiaozhuang University, Nanjing 211171, China
Published: December 2020

In this work, we study the chaos-control and parallel queue synchronization of a laser local area network (LAN). We present and study specifically a “single-queue-double-parameter” method of the parallel series queue dynamic behavior synchronization of the controlled laser LAN under two optoelectronic delay feedback controllers, and establish the mathematical and physical model of the controlled laser LAN. The LAN node is composed of two space coupled lasers with different parameters and other two single lasers, where two lasers series produce two different parallel queues, which results in two different chains of LAN nodes. Optical LAN links are composed of two optical parallel-crossing paths and two photoelectric delay feedback controllers setting in two lasers of LAN, which creates a method of double-parameter control of LAN. Through the analysis of the stability theory of differential equation and the dynamic characteristic equation of coupled lasers of LAN, our mathematical theory demonstrates that the chaos-control of laser LAN can be achieved by two photoelectric delay feedback controllers adjusting photoelectric feedback levels and feedback delay time of one of the two coupled laser and another single laser, respectively. Making analysis of the stability theory of differential equation and the dynamic characteristic equation of LAN nodes in two queue chains, we demonstrate theoretically how to obtain synchronization in network nodes of the controlled LAN on two queue chains by controlling optical feedback levels, and by the photoelectric delay feedback controllers adjusting photoelectric feedback levels and feedback delay time, respectively. Using our numerical calculation of parallel queue synchronization, the node laser’s waveform and its phase space trajectory, we find that very lasers of network nodes of the controlled LAN can lead to the parallel queue synchronization of a double-period, a three-period, a four-period and other quasi-periods while these quasi-periodic synchronizations and dynamic synchronizations are controlled in two queue chains of LAN nodes when we let the photoelectric feedback level and the delay time shift on some parameters. We find also two controlled quasi-periodic parallel queue synchronization regions. This paper also presents an application case of laser LAN multi-point chaotic carrier synchronous emission and ultra-wideband communication. This is a new type of controlled laser LAN system, which has the core elements of optical LAN and the characteristics of multi-variable, multi-dimension and parallel queue chaos-control techniques of complex dynamic networks. It also has the function of optical network ultra-wideband communication. The results have important reference value for studying the LAN, optical network and its synchronization and control, laser technology and chaos.
Nano-friction phenomena in driven Frenkel-Kontorova model with stochastic excitation
Authors: Li Yi-Wei , Lei You-Ming , Yang Yong-Ge ,   Department of Mathematics, Shanxi Agricultural University, Jinzhong 030801, China,   Department of Applied Mathematics, Northwestern Polytechnical University, Xi’an 710129, China,   School of Applied Mathematics, Guangdong University of Technology, Guangzhou 510520, China
Published: December 2020

In this paper, the effects of a Gaussian white noise excitation on the one-dimensional Frenkel-Kontorova (FK) model are studied by the stochastic Runge-Kutta method under two different types of substrate cases, i.e. incommensurate case and commensurate case. The noise excitation is considered through the inclusion of a stochastic force via a Langevin molecular dynamics approach, and we uncover the mechanism of nano-friction phenomenon in the FK model driven by the stochastic force. The relationship between the noise intensity and the nano-friction phenomenon, such as hysteresis, maximum static friction force, and the super-lubricity, is investigated by using the stochastic Runge-Kutta algorithm. It is shown that with the increase of noise intensity, the area of the hysteresis becomes smaller and the maximum static friction force tends to decrease, which can promote the generation of super-lubricity. Similar results are obtained from the two cases, in which the ratios of the atomic distance to the period of the substrate potential field are incommensurate and commensurate, respectively. In particular, a suitable noise density gives rise to super-lubricity where the maximum static friction force vanishes. Hence, the noise excitation in this sense is beneficial to the decrease of the hysteresis and the maximum static friction force. Meanwhile, with the appropriate external driving force, the introduction of a noise excitation can accelerate the motion of the system, making the atoms escape from the substrate potential well more easily. But when the chain mobility reaches a saturation state (B = 1), it is no longer affected by the stochastic excitation. Furthermore, the difference between the two circumstances lies in the fact that for the commensurate interface, the influence of the noise is much stronger and more beneficial to triggering the motion of the FK model than for the incommensurate interface since the atoms in the former case are coupled and entrapped more strongly by the substrate potential.
Control of spiral wave and spatiotemporal chaos in two-layer aging cardiac tissues
Authors: Li Qian-Yun , Bai Jing , Tang Guo-Ning ,   College of Physical Science and Technology, Guangxi Normal University, Guilin 541004, China
Published: December 2020

Cardiac arrhythmias can be caused by the occurrence of electrical spiral waves and spatiotemporal chaos in the cardiac tissues, as well as by the changes of cardiac tissues resulting from the electrical coupling of cardiomyocytes to fibroblasts (M-F coupling). How to control the arrhythmia induced by spiral wave or spatiotemporal chaos is the problem which has attracted much attention of scientists. In this paper, a two-layer composite medium is constructed by using cardiomyocytes and fibroblasts. Luo-Rudy phase I cardiac model and passive model of fibroblast are used to study the effects of the M-F coupling on the formation of spiral wave and the control of spiral wave and spatiotemporal chaos in a two-layer composite medium. A control scheme that the spiral waves and spatiotemporal chaos are controlled by increasing the coupling strength between cells is proposed. The numerical results show that the M-F coupling has an important influence on the dynamics of spiral wave. With the increase of the density of fibroblasts, the M-F coupling may result in spiral wave meandering and spiral wave breaking into spatiotemporal chaos, and even induce the transition from spatiotemporal chaos (or spiral wave) to no wave. The eliminating spiral wave and spatiotemporal chaos in the composite medium by increasing the coupling strength between cells is only effective in most of cases, depending on the role played by fibroblasts. When fibroblasts act as current sinks for the cardiomyocyte, the spiral wave and spatiotemporal chaos are effectively eliminated only in most of cases by increasing the coupling strength between cells, and the controlled area is small. When fibroblasts act as a current source for the cardiomyocyte, increasing the coupling strength between cells to a value higher than a critical value can effectively terminate spiral wave and spatiotemporal chaos, and the controllable area is greatly increased compared with the former. Increasing the coupling strength between cardiomyocytes is a key factor in controlling the spiral waves and spatiotemporal chaos.
Numerical simulation and experimental study of high-power thermal equilibrium inductively coupled plasma
Authors: Niu Yue , Bao Wei-Min , Li Xiao-Ping , Liu Yan-Ming , Liu Dong-Lin ,   School of Aerospace Science and Technology, Xidian University, Xi’an 710071, China
Published: December 2020

Inductively coupled plasma generator is one of the core components of the near-space high-speed target plasma electromagnetic scientific experimental research device, which is often used to simulate high enthalpy and high speed plasma sheath environment. In order to study the discharge characteristics of inductively coupled plasma generator under high power, radio frequency and medium pressure, the numerical simulation and experiment are combined to study its internal heat transfer and flow characteristics in this paper. Based on the local thermodynamic equilibrium conditions, the numerical simulation of large-scale radio frequency and medium pressure inductively coupled plasma with a power of 100–400 kW is carried out through the multi-field coupling of flow, electromagnetic and temperature field, and verified by light intensity and spectrum experiment. The results show that the electromagnetic field distribution in the high-power thermal balance inductively coupled plasma generator is similar to that of the small- and medium-sized power plasma generator. The discharge energy dissipation occurs mainly in the area where the induction coil is located. The temperature of the inner wall of the quartz tube is higher at the coil location than in other areas, and the plasma has a ring-shaped high-temperature structure. The outer wall of the quartz tube is set to be the boundary condition of heat flux for simulating the temperature change of the quartz tube under cold blowing. This setting is in coincidence with factual situations. The wall temperature of the quartz tube at the entrance and at the induction coil section are found to be relatively high. When the large-size inductively coupled plasma generator works, an obvious return vortex is generated at the entrance due to the temperature difference and the electromagnetic pumping effect, and the exit velocity increases slightly with the increase of power. At the same time, the discharge experiment under the corresponding conditions shows that there is found a ring structure with bright edges and dark centers in the axial image of the argon discharge. Moreover, the emission spectrum of argon plasma is measured through the spectrum diagnosis system and the spatial distribution of the generator electron temperature is obtained. The light intensity of the discharge image and the electron temperature measured by the spectrum are found to be in comparative coincidence with the COMSOL simulation temperature result, demonstrating the validity of the numerical simulation results under thermodynamic equilibrium conditions. The numerical simulation results in this paper are also applicable to the optimization design and temperature resistance evaluation of the inductively coupled plasma generator.
Localization and intensity calibration of partial discharge based on attenuation effect of ultrasonic sound pressure
Authors: Wang Yu-Long , Zhang Xiao-Hong , Li Li-Li , Gao Jun-Guo , Guo Ning , Cheng Cheng ,   Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China,   College of Rongcheng, Harbin University of Science and Technology, Rongcheng 264300, China,   Siping power Supply Company, State Grid Jilin Sheng Electric Power Co., LTD. Siping 136000, China
Published: December 2020

In the insulation system of power equipment, the partial discharge (PD) of short period does not cause the insulation to produce the penetrating breakdown, however the long-term PD of is one of the important causes of local deterioration, and even breakdown in dielectric. Therefore, it is very important to study the location of PD source and the calibration of discharge intensity. To achieve this, in this paper we take the needle-plate discharge model for example and go through the following steps respectively. Firstly, combined with the positive correlation between the ultrasonic signal and the apparent discharge magnitude in the process of PD, the ultrasonic method to detect partial discharge can be implemented. Then, based on the principle of time difference of arrival method (TDOAM), the accuracy of location is analyzed by using quantum genetic algorithm (QGA), genetic algorithm (GA), simulated annealing algorithm (SAA), particle swarm optimization (PSO) and generalized cross correlation method (GCC), respectively. And thus, starting from the study of the attenuation effect of sound pressure caused by the propagation loss, reflection and refraction of acoustic wave, the calibration model of PD intensity is established for the first time after determining the location of PD source with high precision. Some important findings are extracted from simulations and experimental results. First, the localization algorithm of PD source with high precision is observed. The localization of PD source by means of QGA is the most accurate, with maximum deviation of (0.27 ± 0.13) cm. Comparing with GA, SAA, PSO and GCC, the accuracy of location is improved by 33.57%, 41.51%, 32.11% and 87.26%, respectively. Second, due to the attenuation effect of sound pressure, when the measured voltage amplitude of ultrasonic signal is the same, the apparent discharge magnitude of PD source gradually increases with the test distance increasing. When the test distance is 37.80 cm, the apparent discharge magnitude of PD source is 633.83 pC, which increases by 28.51% compared with 7.00 cm. Moreover, simulation results and measurement results are compared with each other and they are well consistent. The discharge curve almost coincides with the calibration fitting curve of PD source when the test distance is 7.00 cm. Finally, it is concluded that the discharge intensity calibration model of PD source is accurate, which is of great significance in evaluating the extent of insulation damage.
Two-photon multifocal structured light microscopy based on high-speed phase-type spatial light modulator
Authors: Yu Huan-Huan , Zhang Chen-Shuang , Lin Dan-Ying , Yu Bin , Qu Jun-Le ,   Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
Published: December 2020

Multifocal structured illumination microscopy (MSIM) can achieve a doubled improvement in the resolution of the diffraction limit within an imaging depth of 50 μm. But when imaging thick samples, scattered light and defocused light limit its optical sectioning capability and image contrast. Two-photon MSIM (2P-MSIM) overcomes the influence of sample tissue scattering and further improves the imaging depth and imaging characteristics. However, the existing 2P-MSIM usually adopts galvanometer based scanning mirrors for precisely scanning imaging, which is a complicated and poor flexibility system. Here we propose a simpler 2P-MSIM. Two-photon multifocal scanning imaging can be realized by a spatial light modulator (SLM) with a high frame rate (< 845 Hz). The phase map of generating multi-focus array and linear phase grating loaded on the SLM simultaneously, high-precision parallel digital random address scanning and excitation imaging on the sample surface can be realized. The mechanical inertia problem of the galvanometer scanner in multifocal imaging can be solved by the proposed method while reducing the complexity of the system and improving flexibility. We finally realize two-photon multifocal imaging of mouse kidney tissue slices and lily of the valley rhizome by this system, which verifies the three-dimensional super-resolution imaging capability of this method. It is of great significance in developing the 2P-MSIM.