Self-organized magnetization patterns in cold atoms

This Thesis reports on a realization of self-organized magnetization patterns in a cloud of cold atoms driven far from equilibrium by a pump laser beam. The experiments are performed in the single mirror feedback configuration, where transverse ordering occurs due to amplification of fluctuations in the atomic medium at critical lengthscales via the optical non-linearity and the Talbot effect. For a linearly polarized pump beam a generation of modulated light with orthogonal polarization is seen to occur, signaling the presence of a polarization instability. Imaging of the refractive index modulations at the end of the cloud reveals complementary regions of the two orthogonal circularly polarized components of the imaged light, which is related to the ordering of atomic spins. A detailed investigation of dependence of pattern properties on the direction and strength of the applied B-fields is presented. In addition to this, a theoretical model describing the dynamics and coupling of atomic magnetic moments and the laser light in the relevant parameter regime is developed and shown to provide good agreement with results of the experiment. Non-equilibrium self-organization of atomic degrees of freedom in cold gases can in some cases be mapped onto phase transitions in condensed matter systems. In this respect, the single mirror feedback configuration is particularly interesting as it provides a simple arrangement where ordering breaks the continuous translational and rotational symmetries of the initial system.This Thesis reports on a realization of self-organized magnetization patterns in a cloud of cold atoms driven far from equilibrium by a pump laser beam. The experiments are performed in the single mirror feedback configuration, where transverse ordering occurs due to amplification of fluctuations in the atomic medium at critical lengthscales via the optical non-linearity and the Talbot effect. For a linearly polarized pump beam a generation of modulated light with orthogonal polarization is seen to occur, signaling the presence of a polarization instability. Imaging of the refractive index modulations at the end of the cloud reveals complementary regions of the two orthogonal circularly polarized components of the imaged light, which is related to the ordering of atomic spins. A detailed investigation of dependence of pattern properties on the direction and strength of the applied B-fields is presented. In addition to this, a theoretical model describing the dynamics and coupling of atomic magnetic moments and the laser light in the relevant parameter regime is developed and shown to provide good agreement with results of the experiment. Non-equilibrium self-organization of atomic degrees of freedom in cold gases can in some cases be mapped onto phase transitions in condensed matter systems. In this respect, the single mirror feedback configuration is particularly interesting as it provides a simple arrangement where ordering breaks the continuous translational and rotational symmetries of the initial system

Superradiance in a Large and Dilute Cloud of Cold Atoms in the Linear-Optics Regime

Superradiance has been extensively studied in the 1970s and 1980s in the regime of superfluores-cence, where a large number of atoms are initially excited. Cooperative scattering in the linear-optics regime, or "single-photon superradiance" , has been investigated much more recently, and superra-diant decay has also been predicted, even for a spherical sample of large extent and low density, where the distance between atoms is much larger than the wavelength. Here, we demonstrate this effect experimentally by directly measuring the decay rate of the off-axis fluorescence of a large and dilute cloud of cold rubidium atoms after the sudden switch-off of a low-intensity laser driving the atomic transition. We show that, at large detuning, the decay rate increases with the on-resonance optical depth. In contrast to forward scattering, the superradiant decay of off-axis fluorescence is suppressed near resonance due to attenuation and multiple-scattering effects

INA brand motor oil packaging system optimization

This paper explores the possibility of INA brand motor oil packaging system optimization. Research has been conducted in order to recognize the typical failure pattern of one-liter motor oil container, according to ASTM D2659-84. The findings of this study identify an opportunity for improvement in primary package design, as well as an overall reduction in expenditure for motor oils packaging as a function of improved distribution process. Based on significant cost savings achieved by packaging system optimization, this project study recommends implementation of the project at INA Maziva Rijeka

Symmetric ordering and Weyl realizations for quantum Minkowski spaces

Symmetric ordering and Weyl realizations for non commutative quantum Minkowski spaces are reviewed. Weyl realizations of Lie deformed spaces and corresponding star products, as well as twist corresponding to Weyl realization and coproduct of momenta are presented. Drinfeld twists understood in Hopf algebroid sense are also discussed. A few examples of corresponding Weyl realizations are given. We show that for the original Snyder space there exists symmetric ordering, but no Weyl realization. Quadratic deformations of Minkowski space are considered and it is demonstrated that symmetric ordering is deformed and a generalized Weyl realization can be defined.Comment: 27 page

Manastir Hilandar i Bugari u XVIII veku: kulturne i ekonomske veze

Dosadašnja proučavanja istorije Hilandara u XVIII veku nisu dovoljno pažnje posvećivala državnim i društvenim okvirima u kojima su monasi živeli. Osamnaesti vek je bio vreme velikih vojnih i ekonomskih izazova, koji su počeli da pokazuju zaostajanje osmanske države u odnosu na njene suparnike. Složene okolnosti osmanske države odrazile su se i na život na Svetoj Gori, i pored njene geografske izdvojenosti i posebnog statusa koji je uživala kao monaška zajednica. Monasi Hilandara, kao i drugih svetogorskih manastira, morali su da dobro poznaju političku i ekonomsku situaciju koja je vladala u Osmanskom carstvu. Zbog toga su u doktorskoj disertaciji unutrašnje uređenje manastira, staranje o postojećim posedima i sticanje novih, kao i odnosi monaha sa svetom van manastirskih zidina, postavljeni u kontekst društvenih i ekonomskih prilika koje su vladale u onovremenom Osmanskom carstvu. Istraživanje se zasnivalo pre svega na izvorima osmanskog porekla, kako onima koji su nastajali u kancelarijama centralnih vlasti (sultanske naredbe, popisi) tako i dokumentima koje su izdavali organi lokalnih vlasti i posebno kadijski sud. Pored toga, kako bi se stekla potpunija slika o monaškog životu i poslovima, analizirani su i slovenski dokumenti sačuvani u manastirskom arhivu, kao i onovremeni putopisi posetilaca Svete Gore. Hilandarci su, nastavljajući da se staraju o svojim posedima na Atonu i u njegovom širem zaleđu, tokom XVIII veka stekli i niz pre svega gradskih metoha na prostoru istočnog Balkana (tj. na prostoru današnje istočne Srbije i Bugarske). Monasi su nekretnine u gradovima i selima sticali kupovinom i kao poklon. Osmanski pravni sistem omogućavao je i nemuslimanima da stvaraju verske zadužbine, te su tako bogatiji članovi pravoslavnih zajednica u balkanskim gradovima svoju religioznost izražavali i kroz čin zadužbinarstva. Mnogobrojne zabeleške u manastirskim delovodnim knjigama svedoče o čestim posetama Hilandaraca istočnobalkanskim gradovima, prilikom kojih su prikupljali milostinju za manastir i obavljali svešteničke dužnosti kada se za time ukazivala potreba. Na taj način Hilandar je potvrdio svoje istaknuto mesto na verskoj mapi Balkana, i jačao ulogu monaha u verskom i kulturnom životu pravoslavnih zajednica. Kao jedna od važnih verskih praksi stanovnika i gradskih i seoskih naselja pokazala su se poklonička putovanja, koja su u Hilandar o velikim praznicima dovodila veliki broj hodočasnika. Još jedan od ciljeva rada bilo je istraživanje u istoriografiji prihvaćene teze o jačanju bugarskog uticaja u Hilandaru od sredine XVIII veka. Na prostoru koji je bio predmet istraživanja među nemuslimanskim stanovništvom dominirao je bugarski etnički elemenat. Međutim, ukazala se potreba da se preispita da li je i koliko etnička pripadnost monaha zaista bila važan činilac monaškog života. Različiti etnički identiteti jesu postojali i njih su stanovnici Osmanskog carstva bili svesni. Međutim, i drugi aspekti identiteta, kao što su osećaj pripadnosti lokalnoj zajednici ili pak sveobuhvatnoj verskoj grupi, igrali su važnu ulogu u svakodnevnom životu. Iako su izvori često nemi kada su u pitanju ovi problemi, jasno je da se dinamika između različitih aspekata višeslojnih identiteta menjala vremenom. Kao studija slučaja, u radu je izabran primer života i delatnosti jednog monaha, Pajsija Hilandarskog. Njegovo delo Istorija slavjanobugarska često je od kraja XIX veka tumačeno kao temelj razvoja bugarske nacionalne ideje. Analizirajući ovo delo u kontekstu njemu savremenih društvenih i kulturnih uslova, prikazane su osnovne ideje Pajsija Hilandarskog i njihov domet. Dvojaki pristup proučavanju istorije Hilandara u XVIII veku ogledao se s jedne strane u posvećivanju pažnje osmanskom kontekstu funkcionisanja manastirske ekonomije, dok je s druge strane prikazano učešće monaha u kulturnim i društvenim tokovima svojstvenim datom periodu. Na takav način pokušano je da se predstavi složenost i višeslojnost monaškog života i uloge Hilandara među pravoslavnim stanovništvom Balkana

History and audiovisual productions: notes on the potential of a relationship: The case of The Twilight Zone (1959-1964) as a source and resource for thinking about the Cold War

Este artículo se propone indagar las posibilidades que presenta la articulación de las producciones audiovisuales (cine, series, documentales) con la historia en dos frentes: como fuente y como recurso para el aula. A partir del análisis de la serie estadounidense The Twilight Zone (Serling, 1959-1964) reflexionaremos sobre su potencialidad para pensar el proceso de la Guerra Fría (1947-1989) desde una perspectiva socio-cultural atendiendo fundamentalmente a las representaciones. Al considerar la serie como fuente para el análisis histórico, The Twilight Zone deja entrever el contexto de producción en los temas y problemas que aborda, en los recursos narrativos a los que apela y en el género en el que se inserta, además de permitir descubrir voces críticas vertidas en el contexto de exacerbación de los conflictos entre los Estados Unidos y su contraparte soviética. Al pensar en The Twilight Zone como recurso para la enseñanza de la historia, la serie se presenta como un insumo potable para llevar al aula para reflexionar en torno a actores, conflictos y representaciones de la Guerra Fría. Las observaciones vertidas aquí son esbozadas para examinar The Twilight Zone en su doble cariz desde una perspectiva social, política y/o ideológica, conformando un acercamiento socio-cultural al periodo en que se produjo, en el que las circunstancias históricas marcadas por la Guerra Fría no pueden ser desconocidas. La reflexión crítica, propia y de los estudiantes, será fundamental para aprovechar en toda su potencialidad las producciones audiovisuales como fuentes y como recursos para la enseñanza de la historia.This article inquires the possibilities of the articulation of audiovisual productions (cinema, series, documentaries) with history on two fronts: as a source and as a resource for the classroom. From the analysis of the american series The Twilight Zone (Serling, 1959-1964) we will reflect on its potential to think about the process of the Cold War (1947-1989) from a socio-cultural perspective, fundamentally attending to representations. Based on considering the series as a source for historical analysis, The Twilight Zone allows a glimpse of the production context through the themes and problems it addresses, the narrative resources it appeals to and the genre in which it is inserted, in addition to allow the discovery of critical voices expressed in the context of the exacerbation of conflicts between the United States and its Soviet counterpart. Thinking of The Twilight Zone as a resource for teaching history, the series is presented as an input to take to the classroom to reflect on actors, conflicts and representations of the Cold War. The observations made here are outlined to think about The Twilight Zone in its double aspect from a social, political and/or ideological perspective, forming a socio-cultural approach to the period in which it was produced, in which the historical circumstances marked by the Cold War cannot be unknown. The critical reflection, one's own and that of students, will be essential to take full advantage of audiovisual productions as sources and resources for teaching history.Fil: Kresic, Agustina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Historia. Centro Lat de Inv En Historia Oral y Social; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Rosario. Investigaciones Socio-historicas Regionales. - Universidad Nacional de Rosario. Investigaciones Socio-historicas Regionales.; Argentin

Female Representation in the Graphics of the Erotic Films of the ‘80: A critical analysis of the tensions between the agency and sexual violence within the framework of the feminist debate proporn vs. anti-porn

Bajo la consideración de que el porno es uno de los dispositivos que configuran el marco epistemológico y de inteligibilidad de la sexualidad, este trabajo articula la dimensión histórica y la de género a partir del análisis de las representaciones que de las mujeres y sus cuerpos aparecían en las gráficas del cine erótico y porno de los años ´80 publicitadas en el diario La Capital (Rosario, Santa Fe). El examen sitúa el problema en dos contextos complementarios: la transición en Argentina, cuando se produjo el llamado destape, y el debate pro-porno vs. anti-porno al interior de los feminismos. Sostenemos que los posters de las películas eróticas y/o pornográficas son una expresión más de las tensiones entre la propia agencia de las mujeres y el lugar de subordinación en las que son ubicadas dentro de la estructura heterocentrada de la narración clásica de estos géneros, en particular, y de la matriz heterocentrada de la sociedad en general.Considering that porn is one of the devices that configure the epistemological and intelligibility framework of sexuality, this work articulates the historical and the gender dimensions based on the analysis of the representations of women and their bodies appeared in the graphics of the erotic and porn cinema of the 80s published in the newspaper La Capital (Rosario, Santa Fe). The examination situates the problem in two complementary contexts: the transition in Argentina, when the so-called destape took place, and the pro-porn vs. anti-porn debate within feminisms. We maintain that the posters of erotic and/or pornographic films are one more expression of the tensions between the agency of women and the place of subordination in which they are located within the heterocentric structure of the classic narration of these genres, in particular, and of the heterocentric matrix of society in general.Fil: Kresic, Agustina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Rosario. Investigaciones Socio-historicas Regionales. - Universidad Nacional de Rosario. Investigaciones Socio-historicas Regionales.; Argentina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Historia. Centro Latinoamericano de Investigaciones en Historia Oral y Social; Argentin