Plasma and Sol-Gel Technology for Creating Nanostructured Surfaces of Fibrous Polymers

For a modification of natural and synthetic fibrous polymers low-pressure ICRF plasma and liquid repellent sol-gel fluoroalkyl-functional siloxane precursor were used. Plasma induced surface chemical and morphological changes on fluorinated poly(ethylene terephthalate) and cellulose were analysed using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Wettability properties of sol-gel functionalized polymers were determined by the goniometric water contact angles and water sliding angle measurements. After plasma treatment the oxygen content on the surface of both polymers increased (increase of O/C ratio) and a nanostructured surface roughness appeared. Plasma ablation caused partially defluorinated nanostructured surface of fluorinated poly(ethylene terephthalate) polymer and increased its hydrophilicity. Plasma activation and etching of cellulose polymer contributed to the creation of highly adhesive and wash resistant sol-gel coating with superhydrophobic, oleophobic and self-cleaning properties. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3539

Twitter-based analysis of the dynamics of collective attention to political parties

Large-scale data from social media have a significant potential to describe complex phenomena in real world and to anticipate collective behaviors such as information spreading and social trends. One specific case of study is represented by the collective attention to the action of political parties. Not surprisingly, researchers and stakeholders tried to correlate parties' presence on social media with their performances in elections. Despite the many efforts, results are still inconclusive since this kind of data is often very noisy and significant signals could be covered by (largely unknown) statistical fluctuations. In this paper we consider the number of tweets (tweet volume) of a party as a proxy of collective attention to the party, identify the dynamics of the volume, and show that this quantity has some information on the elections outcome. We find that the distribution of the tweet volume for each party follows a log-normal distribution with a positive autocorrelation of the volume over short terms, which indicates the volume has large fluctuations of the log-normal distribution yet with a short-term tendency. Furthermore, by measuring the ratio of two consecutive daily tweet volumes, we find that the evolution of the daily volume of a party can be described by means of a geometric Brownian motion (i.e., the logarithm of the volume moves randomly with a trend). Finally, we determine the optimal period of averaging tweet volume for reducing fluctuations and extracting short-term tendencies. We conclude that the tweet volume is a good indicator of parties' success in the elections when considered over an optimal time window. Our study identifies the statistical nature of collective attention to political issues and sheds light on how to model the dynamics of collective attention in social media.Comment: 16 pages, 7 figures, 3 tables. Published in PLoS ON

RF wall conditioning at the Uragan-2M with use of high vacuum cryogenic trap

The results of evaluating the effectiveness of the vacuum chamber wall conditioning procedure by the use VHF of continuous discharge and RF pulse discharge that were applied either separately or in combination with each other in helium atmosphere at Uragan-2M are presented. The high-vacuum cryogenic traps are enabled in these experiments. Some amount of gas pumped from the vacuum chamber is condensed on the surfaces of cryogenic traps integrated in the input branch pipes of the vacuum system. Periodically, one trap is separated from the chamber and from the pump by vacuum valves and warmed up what led to release of the condensed gases into the enclosed volume. The value of pressure Pg inside this volume is proportional to the amount of pumped gas and, consequently, to the effectiveness of the wall conditioning process. It was found that the value Pg in the combined VHF + RF discharge is 2-3 times higher than in the case of using only pulsed RF discharge.Приведены результаты ВЧ-чистки в стеллараторе Ураган-2М с использованием УКВ непрерывного разряда в атмосфере гелия. При этом часть откачиваемого газа конденсировалась на криогенную ловушку. Процесс чистки контролировался измерением давления газа Pг в отсеченном объеме с ловушкой после ее отепления. Значение Pг пропорционально количеству откачиваемого газа. Обнаружено, что количество сконденсированного на ловушке газа при комбинированном УКВ+ВЧ-разряде в 2-3 раза выше, чем в случае использования только импульсного ВЧ-разряда.Наведено результати ВЧ-чистки в стелараторі Ураган-2М з використанням УКХ безперервного розряду в атмосфері гелію. При цьому частина відкачуваного газу конденсувалась на криогенну пастку. Процес чищення контролювався за допомогою вимірювання тиску газу Pг у відсіченому об`ємі з пасткою після її отеплення. Значення Pг пропорційно кількості відкачуваного газу. Виявлено, що кількість сконденсованого на пастці газу при комбінованому УКХ + ВЧ-розряді в 2-3 рази вище, ніж у випадку використання тільки імпульсного ВЧ-розряду

The Effects of Twitter Sentiment on Stock Price Returns

Social media are increasingly reflecting and influencing behavior of other complex systems. In this paper we investigate the relations between a well-know micro-blogging platform Twitter and financial markets. In particular, we consider, in a period of 15 months, the Twitter volume and sentiment about the 30 stock companies that form the Dow Jones Industrial Average (DJIA) index. We find a relatively low Pearson correlation and Granger causality between the corresponding time series over the entire time period. However, we find a significant dependence between the Twitter sentiment and abnormal returns during the peaks of Twitter volume. This is valid not only for the expected Twitter volume peaks (e.g., quarterly announcements), but also for peaks corresponding to less obvious events. We formalize the procedure by adapting the well-known "event study" from economics and finance to the analysis of Twitter data. The procedure allows to automatically identify events as Twitter volume peaks, to compute the prevailing sentiment (positive or negative) expressed in tweets at these peaks, and finally to apply the "event study" methodology to relate them to stock returns. We show that sentiment polarity of Twitter peaks implies the direction of cumulative abnormal returns. The amount of cumulative abnormal returns is relatively low (about 1-2%), but the dependence is statistically significant for several days after the events

Integrated network models for predicting ecological thresholds::Microbial – carbon interactions in coastal marine systems

7siThis proof of concept study presents a Bayesian Network (BN) approach that integrates relevant biological and physical-chemical variables across spatial (two water layers) and temporal scales to identify the main contributing microbial mechanisms regulating POC accumulation in the northern Adriatic Sea. Three scenario tests (diatom, nanoflagellate and dinoflagellate blooms) using the BN predicted diatom blooms to produce high chlorophyll a at the water surface while nanoflagellate blooms were predicted to occur also at lower depths (>5 m) in the water column and to produce lower chlorophyll a concentrations. A sensitivity analysis using all available data identified the variables with the greatest influence on POC accumulation being the enzymes, which highlights the importance of microbial community interactions. However, the incorporation of experimental and field data changed the sensitivity of the model nodes ≥25% in the BN and therefore, is an important consideration when combining manipulated data sets in data limited conditions.noneopenMcDonald K.S.; Turk V.; Mozetic P.; Tinta T.; Malfatti F.; Hannah D.M.; Krause S.Mcdonald, K. S.; Turk, V.; Mozetic, P.; Tinta, T.; Malfatti, F.; Hannah, D. M.; Krause, S

Social democracy, embeddedness and decommodification: On the conceptual innovations and intellectual affiliations of Karl Polanyi

Of the several debates that revolve around the work of the economic historian and political economist Karl Polanyi, one that continues to exercise minds concerns his analysis of, and political attitudes toward, post-war capitalism and the welfare state. Simplified a little, it is a debate with two sides. To borrow Iván Szelényi's terms, one side constructs a ‘hard’ Karl Polanyi, the other a ‘soft’ one. The former advocated a socialist mixed economy dominated by redistributive mechanisms. He was a radical socialist for whom the market should never be the dominant mechanism of economic coordination. His ‘soft’ alter ego insisted that the market system remain essentially intact but be complemented by redistributive mechanisms. The ‘double movement’ – the central thesis of his ‘Great Transformation’ – acts, in this reading, as a self-correcting mechanism that moderates the excesses of market fundamentalism; its author was positioned within the social-democratic mainstream for which the only realistic desirable goal is a regulated form of capitalism. In terms of textual evidence there is much to be said for both interpretations. In this article I suggest a different approach, one that focuses upon the meaning of Polanyi's concepts in relation to their socio-political and intellectual environment

Phytoplankton across Tropical and Subtropical Regions of the Atlantic, Indian and Pacific Oceans

Postprint4,411

Plasma-wall interaction studies within the EUROfusion consortium: Progress on plasma-facing components development and qualification

This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.The provision of a particle and power exhaust solution which is compatible with first-wall components and edge-plasma conditions is a key area of present-day fusion research and mandatory for a successful operation of ITER and DEMO. The work package plasma-facing components (WP PFC) within the European fusion programme complements with laboratory experiments, i.e. in linear plasma devices, electron and ion beam loading facilities, the studies performed in toroidally confined magnetic devices, such as JET, ASDEX Upgrade, WEST etc. The connection of both groups is done via common physics and engineering studies, including the qualification and specification of plasma-facing components, and by modelling codes that simulate edge-plasma conditions and the plasma-material interaction as well as the study of fundamental processes. WP PFC addresses these critical points in order to ensure reliable and efficient use of conventional, solid PFCs in ITER (Be and W) and DEMO (W and steel) with respect to heat-load capabilities (transient and steady-state heat and particle loads), lifetime estimates (erosion, material mixing and surface morphology), and safety aspects (fuel retention, fuel removal, material migration and dust formation) particularly for quasi-steady-state conditions. Alternative scenarios and concepts (liquid Sn or Li as PFCs) for DEMO are developed and tested in the event that the conventional solution turns out to not be functional. Here, we present an overview of the activities with an emphasis on a few key results: (i) the observed synergistic effects in particle and heat loading of ITER-grade W with the available set of exposition devices on material properties such as roughness, ductility and microstructure; (ii) the progress in understanding of fuel retention, diffusion and outgassing in different W-based materials, including the impact of damage and impurities like N; and (iii), the preferential sputtering of Fe in EUROFER steel providing an in situ W surface and a potential first-wall solution for DEMO.European Commission; Consortium for Ocean Leadership 633053; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Debunking in a world of tribes

Social media aggregate people around common interests eliciting collective framing of narratives and worldviews. However, in such a disintermediated environment misinformation is pervasive and attempts to debunk are often undertaken to contrast this trend. In this work, we examine the effectiveness of debunking on Facebook through a quantitative analysis of 54 million users over a time span of five years (Jan 2010, Dec 2014). In particular, we compare how users usually consuming proven (scientific) and unsubstantiated (conspiracy-like) information on Facebook US interact with specific debunking posts. Our findings confirm the existence of echo chambers where users interact primarily with either conspiracy-like or scientific pages. However, both groups interact similarly with the information within their echo chamber. Then, we measure how users from both echo chambers interacted with 50,220 debunking posts accounting for both users consumption patterns and the sentiment expressed in their comments. Sentiment analysis reveals a dominant negativity in the comments to debunking posts. Furthermore, such posts remain mainly confined to the scientific echo chamber. Only few conspiracy users engage with corrections and their liking and commenting rates on conspiracy posts increases after the interaction

Removal of hydrogenated carbon deposits formed in fusion reactors with carbon walls by reactive oxygen particles

A method for removal of hydrogenated carbon deposits from the walls of fusion reactors with carbon divertors is presented. The method is based on interaction of neutral oxygen atoms with deposits at elevated temperatures typically found in such fusion reactors. The source of neutral oxygen atoms is oxygen plasma created with electrodeless high frequency discharges. The density of oxygen atoms in such plasma may approach 1022 m-3 making such discharges suitable for removal of deposits in huge systems like tokamaks