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4434Nonlinear Dynamics and Chaos
http://www.merlot.org/merlot/viewMaterial.htm?id=987443
'This course of 25 lectures, filmed at Cornell University in Spring 2014, is intended for newcomers to nonlinear dynamics and chaos. It closely follows Prof. Strogatz's book, "Nonlinear Dynamics and Chaos: With Applications to Physics, Biology, Chemistry, and Engineering.״ The mathematical treatment is friendly and informal, but still careful. Analytical methods, concrete examples, and geometric intuition are stressed. The theory is developed systematically, starting with first-order differential equations and their bifurcations, followed by phase plane analysis, limit cycles and their bifurcations, and culminating with the Lorenz equations, chaos, iterated maps, period doubling, renormalization, fractals, and strange attractors. A unique feature of the course is its emphasis on applications. These include airplane wing vibrations, biological rhythms, insect outbreaks, chemical oscillators, chaotic waterwheels, and even a technique for using chaos to send secret messages. In each case, the scientific background is explained at an elementary level and closely integrated with the mathematical theory. The theoretical work is enlivened by frequent use of computer graphics, simulations, and videotaped demonstrations of nonlinear phenomena.The essential prerequisite is single-variable calculus, including curve sketching, Taylor series, and separable differential equations. In a few places, multivariable calculus (partial derivatives, Jacobian matrix, divergence theorem) and linear algebra (eigenvalues and eigenvectors) are used. Fourier analysis is not assumed, and is developed where needed. Introductory physics is used throughout. Other scientific prerequisites would depend on the applications considered, but in all cases, a first course should be adequate preparation.'Nonlinear Dynamics and Chaos
http://www.merlot.org/merlot/viewMaterial.htm?id=987463
'This textbook is aimed at newcomers to nonlinear dynamics and chaos, especially students taking a first course in the subject. The presentation stresses analytical methods, concrete examples and geometric intuition. The theory is developed systematically, starting with first-order differential equations and their bifurcations, followed by phase plane analysis, limit cycles and their bifurcations, and culminating with the Lorenz equations, chaos, iterated maps, period doubling, renormalization, fractals, and strange attractors.A unique feature of the book is its emphasis on applications. These include mechanical vibrations, lasers, biological rhythms, superconducting circuits, insect outbreaks, chemical oscillators, genetic control systems, chaotic waterwheels, and even a technique for using chaos to send secret messages. In each case, the scientific background is explained at an elementary level and closely integrated with the mathematical theory.Richly illustrated, and with many exercises and worked examples, this book is ideal for an introductory course at the junior/senior or first-year graduate level. It is also ideal for the scientist who has not had formal instruction in nonlinear dynamics, but who now desires to begin informal study. The prerequisites are multivariable calculus and introductory physics.'Ultracold atomic gases as quantum abacus beads
http://www.merlot.org/merlot/viewMaterial.htm?id=968876
This video was recorded at Kolokviji na Institutu "Jožef Stefan״. Atomic gases can be cooled down to extremely low temperatures (a few nano-Kelvin above absolute zero) when they start behaving as quantum fluids. The physics of these systems has advanced considerably over the past decade because experiments can trap such ultracold gases in versatile geometries, their interactions can be tuned, and they can be kept isolated from the environment for sufficiently long times to preserve their quantum nature. These advances have opened the possibility to experimentally realize one-dimensional atomic gases so that they behave as quantum abacus beads. Such peculiar quantum systems of many particles can in some cases be theoretically understood exactly, which is not the case for most quantum systems. This gives an unprecedented opportunity to investigate strongly correlated states of matter, in and out of equilibrium, both theoretically and experimentally. We will present a general introduction of these systems and our selected results based on exact solutions in these systems. Finally, it will be shown that besides probing low dimensional quantum gases, these systems hold the potential to realize models in more than three dimensions.Graphene and Graphene Device Integration: A Materials Perspective
http://www.merlot.org/merlot/viewMaterial.htm?id=968897
This video was recorded at Kolokviji na Institutu "Jožef Stefan״. In the past decade, the state-of-the-art silicon-based electronics has gone from devices at or above 100 nm to the realm of 30 nm and below. In order to address the power issues the industry is facing as CMOS devices are scaled further, a program called Nanoelectronic Research Initiative was created to develop new materials and devices that take advantage of new state variables with the objective of improving performance per power density. Graphene, a monolayer of carbon atoms arranged in a honeycomb lattice, has recently been subject of considerable theoretical and experimental interest because of its unique transport properties together with exceptional chemical and physical properties. New devices taking advantage of the theoretical prediction on the existence of a Bose-Einstein condensate in bi-layer graphene films, graphene based tunnel FETs, lateral tunnel FETs, and Veselago lens based devices have been proposed. However, in order to demonstrate that any of the proposed can meet the most basic device requirements, high quality films will have to be developed and integrated with dielectrics and metal contacts. We will review the need for devices beyond CMOS, growth of large area graphene and integration of dielectrics and metal contacts with graphene and their effects on field effect transistors characteristics.Vortices and superfluidity in exciton-polariton condensates
http://www.merlot.org/merlot/viewMaterial.htm?id=968903
This video was recorded at Dnevi Jožefa Stefana na Institutu "Jožefa Stefana״. Polaritons are amazing quasiparticles originating from the coupling of photons with excitons (electron‐hole pairs in semiconductors). Polariton condensates may be created both spontaneously through a "standard" phase transition towards a Bose-Einstein condensate, or be resonantly driven with a well‐defined initial phase, speed and spatial distribution. Thanks to the photonic component of polaritons, the properties of the quantum fluid may be accessed very directly, with in particular the possibility of detailed interferometric studies. This allows for example to probe the long‐range coherence properties of a quantum fluid with unprecedented ease. This also allows testing superfluid properties with great precision in space and time. Here, I will describe the static and dynamics of vortices in polariton condensates, obtained with a picosecond time resolution, in different configurations, with in particular their phase configuration. I will show in particular the dynamics of spontaneous creation of a vortex as well as the dissociation of a full vortex into two half vortices. I will also highlight some of the recent results obtained through the shaping of the system, either using nanotechnology processes, or using all optical means, or both of them. This allows in particular the study superfluid hydrodynamics of polariton fluids.The study of molecular disease profiles with mass spectrometry based molecular imaging approaches
http://www.merlot.org/merlot/viewMaterial.htm?id=968931
This video was recorded at Kolokviji na Institutu "Jožef Stefan״. The study of molecular signaling processes related to disease requires not only the detection and analysis of the molecules involved but also the evaluation of their spatial organization. Many molecular imaging modalities have addressed the different levels of complexity of cancer, and mass spectrometry imaging was added to the multimodal toolbox three decades ago. We have developed a multimodal approach that combines a number of innovative mass spectrometric imaging approaches with optical imaging, magnetic resonance imaging and targeted immunohistochemistry images to refine our understanding of disease progression. In addition we have integrated state-of-the-art quantitative proteomics and metabolomic studies of selected tissues in our molecular imaging workflow. We will discuss applications of new chemical microscopes in biomedical tissue analysis targeting cancer research in particular, and showhow the multimodal mass spectrometry imaging can elucidate the way in which local environments can influence signaling pathways in diseases..Experiments with Active Emulsions
http://www.merlot.org/merlot/viewMaterial.htm?id=968937
This video was recorded at Kolokviji na Institutu "Jožef Stefan״. Experiments are presented with emulsions showing various types of 'active' collective behavior. Ensembles of aqueous droplets containing Belouzov-Zhabotinski (BZ) oscillators are shown to exhibit coupling patterns depending on the formation of lipid bilayers between them. We observe target waves, quorum sensing, and spiral waves in two-dimensional rafts of mono-disperse emulsions. As the volume fraction of the dispersed phase (i.e., the droplets) is reduced, we observe self-propelled motion of the droplets, which can be controlled by the BZ reaction if desired. We propose a simple mechanism based on Marangoni stresses which accounts for this motion. Swarming is shown to exhibit pronounced correlation features which depend strongly on the raft density. While the bromine release provides the energy source for this type of self-propulsion, we present an alternative system based on liquid crystals which shows similar collective behaviour, but whose motion has a longer lifetime and is fuelled by the spontaneous formation of a microemulsion. Based on the meso-structure of the liquid crystal, it enables, aside from simple droplet motion, much more complex patterns to evolve, the details of which are yet far from understood.Science in very high magnetic fields: NMR investigations of exotic quantum spin states
http://www.merlot.org/merlot/viewMaterial.htm?id=968941
This video was recorded at Kolokviji na Institutu "Jožef Stefan״. After a short introduction presenting Grenoble High Magnetic Field Laboratory and its high-field NMR facility, we will illustrate possibilities of high-field NMR in Solid State Physics on several examples of low-dimensional, quantum, antiferromagnetic spin systems. We further focus on two types of 2D, dimer, spin systems, which give raise to very different ground states under an applied magnetic field. One example is the "Shastry-Sutherland" compound SrCu2(BO3)2, which exhibits magnetization plateaus at fractional values of the saturation magnetization. In this compound plateaus appear because the kinetic energy of the triplet excitations is strongly reduced by frustration, so that the triplets can crystallize into a commensurate super-lattice. NMR signature of such a super-lattice in the 1/8 magnetization plateau of SrCu2(BO3)2 is a unique observation of this type of magnetization plateau created by spontaneous breaking of translational symmetry [1]. We shall also discuss some new results on the magnetic ground states at fields above the 1/8 plateau (i.e. above 28.4 T), which seemed to be a candidate for a supersolid phase. Another type of 2D spin system is represented by the so-called "Han purple" compound, BaCuSi2O6, for which there is no magnetic frustration, and in which a (2D) Bose-Einstein condensation of triplet excitations occurs above 23.35 T. We shall present a microscopic picture of this complicated high field phase, in which NMR data reveal that the average boson density in the condensate is strongly modulated along the direction perpendicular to the 2D planes, with a density ratio for every second plane nA/nBPhysics, chemistry and materials science in very high magnetic fields: Nuclear Magnetic Resonance and beyond
http://www.merlot.org/merlot/viewMaterial.htm?id=968965
This video was recorded at Kolokviji na Institutu "Jožef Stefan״. High magnetic fields are one of the most powerful tools to study, modify and control the different states of matter. Whereas commercial state-of-the-art superconducting magnets reach magnetic fields up to 23 T, higher fields are only available at a small number of specialized large-scale facilities. In Europe there are three major high field laboratories providing access for external users: HLD Dresden, HFML Nijmegen and LNCMI Grenoble-Toulouse, recently united in the European Magnetic Field Laboratory (EMFL). First, we will present the infrastructure of the Grenoble EMFL laboratory and its available experimental techniques. Second, we will focus on very high field solid-state nuclear magnetic resonance (NMR), a powerful microscopic method for investigating many problems in physics, chemistry and materials science. Recently, the options for NMR at Grenoble have been extended to very high magnetic fields (35 T) and frequencies (1.5 GHz), to very low temperatures (50 mK) as well as towards enhanced sensitivity and resolution (10 ppm). Using selected recent research projects we will demonstrate the potential of the available NMR instrumentation.Raziskave o družini Einstein in o obisku Hansa Alberta Einsteina leta 1971 na Institutu »Jožef Stefan«
http://www.merlot.org/merlot/viewMaterial.htm?id=968973
This video was recorded at Dnevi Jožefa Stefana na Institutu "Jožefa Stefana״. Leta 1971 je Institut »Jožef Stefan« obiskal Hans Albert Einstein, sin Alberta Einsteina in Mileve Marić, tudi sam znanstvenik svetovnega slovesa. O ozadju tega obiska v Sloveniji ter o življenju družine Einstein, ki že od nekdaj vzbuja zanimanje splošne javnosti, bo pripovedoval mag. Djordje Krstić. Mag. Krstić že več desetletij raziskuje življenje družine Einstein in velja za enega večjih poznavalcev. Njegovi zapiski so bili prevedeni v več jezikov, knjiga Mileva in Albert Einstein je izšla tudi v slovenščini.