Finite temperature QCD in the quark-composites approach

We investigate QCD at finite temperature in the quark composites approach, which is based on the use of quark composites with hadronic quantum numbers as fundamental variables. We find that chiral symmetry restoration and quark deconfinement are one and the same first order phase transition, whose critical temperature, in a one loop approximation, is $T= 2\sqrt{\Omega} \rho^{-2}m_{\pi}$, where $m_{\pi}$ is the pion mass, $\Omega=24$ the number of up and down quark components, and $\rho$ a parameter of order 1 whose precise value can be determined by the study of the pion-pion interaction.Comment: LaTex, 5 page

Some homogenization and corrector results for nonlinear monotone operators

This paper deals with the limit behaviour of the solutions of quasi-linear equations of the form \ \ds -\limfunc{div}\left(a\left(x, x/{\varepsilon _h},Du_h\right)\right)=f_h on $\Omega$ with Dirichlet boundary conditions. The sequence $(\varepsilon _h)$ tends to $0$ and the map $a(x,y,\xi )$ is periodic in $y$, monotone in $\xi$ and satisfies suitable continuity conditions. It is proved that $u_h\rightarrow u$ weakly in $H_0^{1,2}(\Omega )$, where $u$ is the solution of a homogenized problem \ -\limfunc{div}(b(x,Du))=f on $\Omega$. We also prove some corrector results, i.e. we find $(P_h)$ such that $Du_h-P_h(Du)\rightarrow 0$ in $L^2(\Omega ,R^n)$

Cyclic Density Functional Theory : A route to the first principles simulation of bending in nanostructures

We formulate and implement Cyclic Density Functional Theory (Cyclic DFT) -- a self-consistent first principles simulation method for nanostructures with cyclic symmetries. Using arguments based on Group Representation Theory, we rigorously demonstrate that the Kohn-Sham eigenvalue problem for such systems can be reduced to a fundamental domain (or cyclic unit cell) augmented with cyclic-Bloch boundary conditions. Analogously, the equations of electrostatics appearing in Kohn-Sham theory can be reduced to the fundamental domain augmented with cyclic boundary conditions. By making use of this symmetry cell reduction, we show that the electronic ground-state energy and the Hellmann-Feynman forces on the atoms can be calculated using quantities defined over the fundamental domain. We develop a symmetry-adapted finite-difference discretization scheme to obtain a fully functional numerical realization of the proposed approach. We verify that our formulation and implementation of Cyclic DFT is both accurate and efficient through selected examples. The connection of cyclic symmetries with uniform bending deformations provides an elegant route to the ab-initio study of bending in nanostructures using Cyclic DFT. As a demonstration of this capability, we simulate the uniform bending of a silicene nanoribbon and obtain its energy-curvature relationship from first principles. A self-consistent ab-initio simulation of this nature is unprecedented and well outside the scope of any other systematic first principles method in existence. Our simulations reveal that the bending stiffness of the silicene nanoribbon is intermediate between that of graphene and molybdenum disulphide. We describe several future avenues and applications of Cyclic DFT, including its extension to the study of non-uniform bending deformations and its possible use in the study of the nanoscale flexoelectric effect.Comment: Version 3 of the manuscript, Accepted for publication in Journal of the Mechanics and Physics of Solids, http://www.sciencedirect.com/science/article/pii/S002250961630368

Antoine-Marie Graziani, Pascal Paoli, Père de la patrie corse, Paris, Tallandier, coll. Figures de proue, 2002, 340 p.

Le matraquage médiatique auquel nous sommes soumis ne saurait nous abuser, ce livre ne relève pas de l'enquête historique. Quelques exemples faciles à vérifier suffiront à s'en convaincre. Je les emprunterai à la période révolutionnaire, et plus particulièrement à celle qui va de la réunion des États généraux à l'insurrection fédéraliste de 1793, qui est à la base même de tous mes travaux. Sur 43 pages (1 634 lignes) que l'auteur lui consacre (pp. 275-317), 14 pages (515 lignes) sont occupées..

Computerspiele und aggressives Verhalten bei Jugendlichen

Diese Diplomarbeit beschäftigt sich mit dem Thema Computerspiele und verschiedenen Formen aggressiven Verhaltens bei Jugendlichen. Dabei sollten folgende Fragen untersucht werden: (1) Wodurch kennzeichnet sich das Computerspielverhalten Jugendlicher? (2) Unterscheiden sich Spieler von Nichtspielern hinsichtlich ihres aggressiven Verhaltens? (3) Unterscheiden sich Gewaltspieler von harmlosen Spielern in Bezug auf aggressives Verhalten? (4) Unterscheiden sich Spieler von Actionspielen von anderen Spielern hinsichtlich aggressiven Verhaltens? Zur Beantwortung der Fragestellungen wurde vom Arbeitsbereich Bildungspsychologie und Evaluation ein Datensatz zur Verfügung gestellt, an dem sich 758 Jugendliche im Alter von ca. 16 Jahren beteiligt haben. Von diesem Datensatz wurden Angaben zu Lieblingstiteln und Spielgewohnheiten sowie 5 Aggressionsskalen verwendet. Die von den Jugendlichen genannten 277 Spieletitel wurden kategorisiert, wobei eine Liste der Top 51 am häufigsten genannten Spieletitel ausgearbeitet wurde. In einem eigenständig entwickelten Online-Fragebogen wurden die Top 51 Spieletitel einem Expertenrating unterzogen. Dabei wurde 19 verschiedenen Experten aus der Computerspielszene eine vorgegebene Gewaltdefinition vorgelegt, die als Basis für die Einschätzung der Spieletitel dienen sollte. Die Experten wurden angewiesen nur jene Spiele einzuschätzen, die ihnen bekannt sind. Für das Rating standen den Experten vier Gewaltkategorien zur Verfügung (extrem, hoch, mittel und gering). Die Auswertung ergab, dass 98% der Jungen, aber nur 57% der Mädchen Computerspiele spielen. Zudem spielen Jungen häufiger Computerspiele als Mädchen. An einem durchschnittlichen Schultag spielen 20% der Jungen, aber nur 7% der Mädchen mehr als 2 Stunden pro Tag Computerspiele. Jungen nennen mit durchschnittlich 2.9 auch mehr Computerspiele als Mädchen (1.7). Die neun beliebtesten Computerspiele machten mit insgesamt 555 Nennungen beinahe die Hälfte aller Spielenennungen (44%) aus. Die Spieletitel lauteten in der Anzahl der Nennungen absteigender Reihenfolge: Counterstrike, Die Sims, Fifa, Need for Speed, Grand Theft Auto, World of Warcraft, Fußball Manager, Age of Empire und Warcraft. Zur Beantwortung der Fragestellung (2) wurden die Jugendliche in die zwei Gruppen „Computerspieler“ und „Nicht-Computerspieler“ eingeteilt. In der Folge wurden Unterschiede zwischen den beiden Gruppen hinsichtlich der 5 Aggressionsskalen untersucht. Die Ergebnisse zeigten, dass Computerspieler höhere Werte in reaktiver Aggression und Viktimisierung aufwiesen als Nicht-Computerspieler. Um die Fragestellung (3) zu beantworten wurden die jugendlichen Spieler je nach Spielgewohnheit in die zwei Gruppen „Gewaltspieler“ und „harmlose Spieler“ unterteilt. Die Berechnungen zeigten ebenfalls Unterschiede zwischen den beiden Gruppen bei reaktiver Aggression. Zur Beantwortung von Fragestellung (4) wurden Spieler in die beiden Gruppen „Actionspiel-Spieler“ und „Nicht-Actionspiel-Spieler“ unterteilt. Dabei stellte sich heraus, dass Actionspiel-Spieler in 4 Aggressionsskalen höhere Werte aufwiesen, als Nicht-Actionspiel-Spieler. Auch bei Kontrolle des Geschlechts blieben signifikante Unterschiede in 3 Aggressionsskalen bestehen. Insgesamt kann also der Schluss gezogen werden, dass das Spielen von Computerspielen allein kein Risikofaktor für aggressives Verhalten darstellt. Das Spielen von Actionspielen stellt jedoch einen Riskofaktor dar, da diese Gruppe deutlich erhöhte Aggressionswerte aufweist.The present study concentrates on playing video games and various forms of aggressive behaviour. The following questions were examined: (1) How can the behaviour of playing computer games of adolescents be described? (2) Are there differences between players and non-players concerning aggressive behaviour? (3) Are there differences between violent players and non-violent players concerning aggressive behaviour? (4) Are there differences between action-players and non-action-players concerning aggressive behaviour? To answer these questions, a dataset of 758 adolescents at the age of about 16 years was provided by the department of Bildungspsychologie und Evaluation. Information about favourite game titles, gaming habits and 5 scales of aggression were used. The adolescents named 277 game titles, which where categorized and a list of the top 51 most named game titles was extracted. After that, a special online questionnaire was developed in order to rate the top 51 game titles according to there violent content. A group of 19 different experts were asked to read a short definition of violence in 4 different categories (extreme, high, medium, low). Consequently the experts were asked to rate the games they knew and had already played themselves. The data analysis showed that 98% of the adolescent players were male, only 57% were female. Males played more often than females. On an average school day, 20% of the male and 7% of the female adolescents played more than 2 hours per day. Male adolescents named with an average of 2.9 more computer games than females with an average of 1.7 game titles. The 9 most popular computer game titles were (beginning with the most popular): Counterstrike, The Sims, Fifa, Need for Speed, Grand Theft Auto, World of Warcraft, Fußball Manager Age of Empire, Warcraft. To answer question (2) the adolescents were divided in two groups, the gamers and the non-gamers. The test for differences between these groups concerning the 5 scales of aggression showed that adolescents playing computer games had higher scores in reactive aggression than the non-players. In order to answer question (3) the adolescents were divided into two groups, according to their game habits: violent players and non-violent players. The data analysis showed that violent players had higher scores in reactive aggression, than non-violent players. To answer question (4) two groups according to the gaming habits concerning the game genre were created: action-players and non-actionplayer. Here, the data analysis showed that action-players had higher scores than the non-action-players in 4 scales of aggression. Controlling the effect of gender showed, that action-players still had higher scores than non-action-players in 3 scales of aggression. From these results we can conclude, that playing computer games alone can not be described a risk factor for violent behaviour. Playing action-games on the other hand seems to be a risk factor, because adolescents from this group showed considerably higher scores in aggression

Determination of S-allele combination in an italian apple (Malus × domestica Borkh.) germplasm core collection

An S-RNase-based gametophytic self-incompatibility (GSI) system, a mechanism that forces outbreeding by preventing self-fertilization, characterizes the genus Malus. Knowledge of the self-incompatibility (S) genotypes of apple cultivars is crucial for choosing pollen donors for fruit production and breeding. Even though the S-allele of most commercial apple cultivars has already been identified, limited information is available about the S-allele diversity within local germplasm collections. In this study, 67 S-allele combinations of local apple accessions were identified. The allele S3 was the most common among local apple accessions followed by S1 and S7. The main aim of this study is to provide new information on cultivar compatibility, and these results will be used to set up new parent selection in apple breeding programmes as well as pollinator selection for the commercial orchard

Produção de biocombustíveis a partir do óleo extraído da biomassa de Tetradesmus obliquus

Orientador: Prof. Dr. André Bellin MarianoTese (doutorado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais. Defesa : Curitiba, 15/12/2022Inclui referênciasÁrea de concentração: Engenharia e Ciências dos MateriaisResumo: A utilização de energias de fontes renováveis se torna cada dia mais necessária, e o Brasil como país que utiliza amplamente a malha rodoviária demanda pelo uso de biocombustíveis. O diesel é um combustível de natureza fóssil e não renovável portanto, seu uso excessivo pode levar a escassez. O biodiesel é um combustível renovável obtido através da reação de óleos vegetais ou gorduras animais com álcoois primários como etanol e metanol. O objetivo deste trabalho foi extrair o óleo da microalga Tetradesmus obliquus, caracteriza-lo e realizar a síntese do biodiesel proveniente do óleo de microalgas. Para extração de lipídios da microalga foram testados diferentes métodos: extração a frio com solventes, a quente com solventes, saponificação e extração por fluido super crítico. O método que apresentou melhores teores de extração de ácidos graxos e material apolar foram os de extração a quente utilizando como solvente etanol e hexano (30:70) obtendo extração de 12,79% de material apolar total e destes 6,51% de ácidos graxos. As amostras obtidas a partir das extrações foram fracionadas através do processo de saponificação: material apolar insaponificável e material saponificável (ácidos graxos). Os ácidos graxos foram esterificados por catalise acida e enzimática e as amostras das duas frações foram submetidas a cromatografia gasosa com detector de massa acoplado para identificação dos compostos de cada amostra. A amostra de ácidos graxos apresentou predominância do ácido graxo C16 palmítico, e dos ácidos graxos C18 oleico, linoleico, linolênico e esteárico. A fração de insaponificáveis apresentou hidrocarbonetos de cadeia longa, como o heptadecano (cerca de 30% de área do cromatograma), mas também em menor quantidade estava presente o octadecano, e um composto naftênico. Os ésteres obtidos através da catalise enzimática tiveram percentual de conversão de 91,3%, enquanto na catalise química houve conversão total, porém, a pureza alcançada após purificação em bauxita foi de 79 e 82%, respectivamente. A análise do ciclo de vida foi realizada para avaliar os impactos ambientais gerados pelos processos empregados neste trabalho, sendo o processo de saponificação o processo mais agressivo ambientalmente devido à alta geração de resíduos durante o processo e a impossibilidade de reutilização da biomassa e reagentes. O óleo obtido da microalga T. obliquus mostrou-se uma alternativa interessante para a geração de biocombustíveis, e novos estudos de purificação dos ésteres e hidrocarbonetos obtidos devem ser realizados a fim de obter altos níveis de pureza para aplicabilidade dos combustíveis.Abstract: Every day the use of renewable energy sources becomes more necessary, and Brazil is a country that widely utilizes it’s road network demands using bio fuels. Diesel is a fossil fuel in its nature so, therefore, its excessive use can lead to shortages. The Bio Diesel is a renewable fuel obtained through the reaction of vegetable oils or animal fats with primary alcohols like ethanol and methanol. This studies objective was to extract oil from the micro algae Tetradesmus obliquus, to categorize it and to synthesize bio diesel from micro algae’s oil. To extract the lipids from micro algae different methods were tested: cold oil extraction with solvents, hot extraction with solvents, saponification and extraction with super critic fluid. The method that showed best levels of fatty acids extraction and non-polar material were the hot extraction using ethanol and hexane as solvent (30:70) obtaining a 12,79% extraction rate of non-polar material in total from what 6,51% were fatty acids. The samples obtained from the extraction were fractionated through the process of saponification: unsaponifiable non-polar material and unsaponifiable material (fatty acids). The fatty acids were esterificated through acid catalysis and enzymatic catalysis and the samples of the two fractions were submitted to a gas chromatography with a mass detector coupled to identify each sample composites. The sample of fatty acids showed predominance of palmitic C16 fatty acid, and oleic C18 fatty acids, linoleic, linolenic and stearic. The fraction of the unsaponifiable showed long chain hydrocarbons like heptadecane (about 30% of the chromatogram area), but also, to a lesser extent, octadecane and a naphthenic compound were present. The esters obtained through enzymatic catalysis had a conversion rate of 91,3% meanwhile the chemical catalysis had a complete conversion, although, it’s purity rate after bauxite purification reached between 79 and 82%, respectively. The life cycle analysis was carried to assess the environment impacts generated by the processes employed in this work, with the saponification process being the most environmentally aggressive process due to the high generation of waste during the process and the impossibility of reusing biomass and reagents. The oil obtained from the microalgae T. obliquus proved to be an interesting alternative for the generation of biofuels, and new purification studies of the esters and hydrocarbons obtained must be carried out in order to obtain high levels of purity for the applicability of the fuels