Das prinzip der erhaltung der energie,

Mode of access: Internet.

Einführung in die allgemeine mechanik zum gebrauch bei vorträgen,

Mode of access: Internet.

University of Michigan Football Team, 1920

Back Row: assistant coach A.J. Sturznegger, Richard Rowland, Frank Czysz, Abe Cohn, George Planck, James Johns, Louis Lehman, William Van Orden, assistatn coach Robert Watson,

Center Row: John Searle, Allen Bailey, Grenville Andrews, Theodore Banks, George Gilmore, Horace Wachter, Frank Steketee, Meyer Paper, Charles Petro, assistant coach Prentiss Douglas

Front Row: Edward Usher, John Perrin, Viggo Nelson, John Dunn, Robert Jerome Dunne, Tad Wieman, head coach Fielding Yost, Angus Goetz, Ernie Vick, Hugh Wilson, Franklin Cappon, William Fortune

University of Michigan Football Team, 1920, full squad posed on practice field

Back Row: assistant coach A.J. Sturznegger, Richard Rowland, Frank Czysz, Abe Cohn, George Planck, James Johns, Louis Lehman, William Van Orden, assistant coach Robert Watson,

Center Row: John Searle, Allen Bailey, Grenville Andrews, Theodore Banks, George Gilmore, Horace Wachter, Frank Steketee, Meyer Paper, Charles Petro, assistant coach Prentiss Douglas

Front Row: Edward Usher, John Perrin, Viggo Nelson, John Dunn, Robert Jerome Dunne, Tad Wieman, head coach Fielding Yost, Angus Goetz, Ernie Vick, Hugh Wilson, Franklin Cappon, William Fortune

Reconstructing Past Climate by Using Proxy Data and a Linear Climate Model

Thesis (Master's)--University of Washington, 2016-06

Experimental tests of quantum nonlinear dynamics in atom optics

Cold atoms in optical potentials provide an ideal test bed to explore quantum nonlinear dynamics. Atoms are prepared in a magneto-optic trap or as a dilute Bose-Einstein condensate and subjected to a far detuned optical standing wave that is modulated. They exhibit a wide range of dynamics, some of which can be explained by classical theory while other aspects show the underlying quantum nature of the system. The atoms have a mixed phase space containing regions of regular motion which appear as distinct peaks in the atomic momentum distribution embedded in a sea of chaos. The action of the atoms is of the order of Planck's constant, making quantum effects significant. This tutorial presents a detailed description of experiments measuring the evolution of atoms in time-dependent optical potentials. Experimental methods are developed providing means for the observation and selective loading of regions of regular motion. The dependence of the atomic dynamics on the system parameters is explored and distinct changes in the atomic momentum distribution are observed which are explained by the applicable quantum and classical theory. The observation of a bifurcation sequence is reported and explained using classical perturbation theory. Experimental methods for the accurate control of the momentum of an ensemble of atoms are developed. They use phase space resonances and chaotic transients providing novel ensemble atomic beamsplitters. The divergence between quantum and classical nonlinear dynamics is manifest in the experimental observation of dynamical tunnelling. It involves no potential barrier. However a constant of motion other than energy still forbids classically this quantum allowed motion. Atoms coherently tunnel back and forth between their initial state of oscillatory motion and the state 180 out of phase with the initial state.

Interpretation of the temperature dependence of rate constants in biosensor studies

A comparison is made between Arrhenius and transition-state analyses of the temperature dependence of rate constants reported in four published biosensor studies. Although the Eyring transition-state theory seemingly affords a more definitive solution to the problem of characterizing the activation energetics, the analysis is equivocal because of inherent assumptions about reaction mechanism and the magnitude of the transmission coefficient. In view of those uncertainties it is suggested that a preferable course of action entails reversion to the empirical Arrhenius analysis with regard to the energy of activation and a preexponential factor. The former is essentially equivalent to the enthalpy of activation, whereas the magnitude of the latter indicates directly the extent of disparity between the frequency of product formation and the universal frequency factor (temperature multiplied by the ratio of the Boltzmann and Planck constants) and hence the likelihood of a more complicated kinetic mechanism than that encompassed by the Eyring transition-state theory. (C) 2004 Elsevier Inc. All rights reserved.

Analysis and optimisation of the performance of nonlinear optical communication systems

We investigate the feasibility of simultaneous suppressing of the amplification noise and nonlinearity, representing the most fundamental limiting factors in modern optical communication. To accomplish this task we developed a general design optimisation technique, based on concepts of noise and nonlinearity management. We demonstrate the immense efficiency of the novel approach by applying it to a design optimisation of transmission lines with periodic dispersion compensation using Raman and hybrid Raman-EDFA amplification. Moreover, we showed, using nonlinearity management considerations, that the optimal performance in high bit-rate dispersion managed fibre systems with hybrid amplification is achieved for a certain amplifier spacing – which is different from commonly known optimal noise performance corresponding to fully distributed amplification. Required for an accurate estimation of the bit error rate, the complete knowledge of signal statistics is crucial for modern transmission links with strong inherent nonlinearity. Therefore, we implemented the advanced multicanonical Monte Carlo (MMC) method, acknowledged for its efficiency in estimating distribution tails. We have accurately computed acknowledged for its efficiency in estimating distribution tails. We have accurately computed marginal probability density functions for soliton parameters, by numerical modelling of Fokker-Plank equation applying the MMC simulation technique. Moreover, applying a powerful MMC method we have studied the BER penalty caused by deviations from the optimal decision level in systems employing in-line 2R optical regeneration. We have demonstrated that in such systems the analytical linear approximation that makes a better fit in the central part of the regenerator nonlinear transfer function produces more accurate approximation of the BER and BER penalty. We present a statistical analysis of RZ-DPSK optical signal at direct detection receiver with Mach-Zehnder interferometer demodulation

Modelagem multiescala de fenômenos eletrocinéticos em meios porosos carregados eletricamente: aplicação a meios porosos argilosos

In this master thesis, we propose a multiscale mathematical and computational model for electrokinetic phenomena in porous media electrically charged. We consider a porous medium rigid and incompressible saturated by an electrolyte solution containing four monovalent ionic solutes completely diluted in the aqueous solvent. Initially we developed the modeling electrical double layer how objective to compute the electrical potential, surface density of electrical charges and considering two chemical reactions, we propose a 2-pK model for calculating the chemical adsorption occurring in the domain of electrical double layer. Having the nanoscopic model, we deduce a model in the microscale, where the electrochemical adsorption of ions, protonation/ deprotonation reactions and zeta potential obtained in the nanoscale, are incorporated through the conditions of interface uid/solid of the Stokes problem and transportation of ions, modeled by equations of Nernst-Planck. Using the homogenization technique of periodic structures, we develop a model in macroscopic scale with respective cells problems for the e ective macroscopic parameters of equations. Finally, we propose several numerical simulations of the multiscale model for uid ow and transport of reactive ionic solute in a saturated aqueous solution of kaolinite. Using nanoscopic model we propose some numerical simulations of electrochemical adsorption phenomena in the electrical double layer. Making use of the nite element method discretize the macroscopic model and propose some numerical simulations in basic and acid system aiming to quantify the transport of ionic solutes in porous media electrically charged.

Modelagem multiescala de fenômenos eletrocinéticos em meios porosos carregados eletricamente: aplicação a meios porosos argilosos

In this master thesis, we propose a multiscale mathematical and computational model for electrokinetic phenomena in porous media electrically charged. We consider a porous medium rigid and incompressible saturated by an electrolyte solution containing four monovalent ionic solutes completely diluted in the aqueous solvent. Initially we developed the modeling electrical double layer how objective to compute the electrical potential, surface density of electrical charges and considering two chemical reactions, we propose a 2-pK model for calculating the chemical adsorption occurring in the domain of electrical double layer. Having the nanoscopic model, we deduce a model in the microscale, where the electrochemical adsorption of ions, protonation/ deprotonation reactions and zeta potential obtained in the nanoscale, are incorporated through the conditions of interface uid/solid of the Stokes problem and transportation of ions, modeled by equations of Nernst-Planck. Using the homogenization technique of periodic structures, we develop a model in macroscopic scale with respective cells problems for the e ective macroscopic parameters of equations. Finally, we propose several numerical simulations of the multiscale model for uid ow and transport of reactive ionic solute in a saturated aqueous solution of kaolinite. Using nanoscopic model we propose some numerical simulations of electrochemical adsorption phenomena in the electrical double layer. Making use of the nite element method discretize the macroscopic model and propose some numerical simulations in basic and acid system aiming to quantify the transport of ionic solutes in porous media electrically charged.

Il ruolo della matematica nella meccanica quantistica in un approccio interdisciplinare per la scuola secondaria

Questo lavoro di tesi nasce all’interno del nucleo di ricerca in didattica della fisica dell’Università di Bologna, coordinato dalla professoressa Olivia Levrini e che coinvolge docenti di matematica e fisica dei Licei, assegnisti di ricerca e laureandi. Negli ultimi anni il lavoro del gruppo si è concentrato sullo studio di una possibile risposta all'evidente e pressante difficoltà di certi docenti nell'affrontare gli argomenti di meccanica quantistica che sono stati introdotti nelle indicazioni Nazionali per il Liceo Scientifico, dovuta a cause di vario genere, fra cui l'intrinseca complessità degli argomenti e l'inefficacia di molti libri di testo nel presentarli in modo adeguato. In questo contesto, la presente tesi si pone l’obiettivo di affrontare due problemi specifici di formalizzazione matematica in relazione a due temi previsti dalle Indicazioni Nazionali: il tema della radiazione di corpo nero, che ha portato Max Planck alla prima ipotesi di quantizzazione, e l’indeterminazione di Heisenberg, con il cambiamento di paradigma che ha costituito per l’interpretazione del mondo fisico. Attraverso un confronto diretto con le fonti, si cercherà quindi di proporre un percorso in cui il ruolo del protagonista sarà giocato dagli aspetti matematici delle teorie analizzate e dal modo in cui gli strumenti della matematica hanno contribuito alla loro formazione, mantenendo un costante legame con le componenti didattiche. Proprio in quest'ottica, ci si accorgerà della forte connessione fra i lavori di Planck e Heisenberg e due aspetti fondamentali della didattica della matematica: l'interdisciplinarietà con la fisica e il concetto di modellizzazione. Il lavoro finale sarà quindi quello di andare ad analizzare, attraverso un confronto con le Indicazioni Nazionali per il Liceo Scientifico e con alcune esigenze emerse dagli insegnanti, le parti e i modi in cui la tesi risponde a queste richieste.

Chemical composition and stable sulfur isotope record of Black Sea sediments

The main terminal processes of organic matter mineralization in anoxic Black Sea sediments underlying the sulfidic water column are sulfate reduction in the upper 2-4 m and methanogenesis below the sulfate zone. The modern marine deposits comprise a ca. 1-m-deep layer of coccolith ooze and underlying sapropel, below which sea water ions penetrate deep down into the limnic Pleistocene deposits from >9000 years BP. Sulfate reduction rates have a subsurface maximum at the SO4[2-]-CH4 transition where H2S reaches maximum concentration. Because of an excess of reactive iron in the deep limnic deposits, most of the methane-derived H2S is drawn downward to a sulfidization front where it reacts with Fe(III) and with Fe2+ diffusing up from below. The H2S-Fe2+ transition is marked by a black band of amorphous iron sulfide above which distinct horizons of greigite and pyrite formation occur. The pore water gradients respond dynamically to environmental changes in the Black Sea with relatively short time constants of ca. 500 yr for SO4[2-] and 10 yr for H2S, whereas the FeS in the black band has taken ca. 3000 yr to accumulate. The dual diffusion interfaces of SO4[2-]-CH4 and H2S-Fe2+ cause the trapping of isotopically heavy iron sulfide with delta34S = +15 to +33 per mil at the sulfidization front. A diffusion model for sulfur isotopes shows that the SO4[2-] diffusing downward into the SO4[2-]-CH4 transition has an isotopic composition of +19 per mil, close to the +23 per mil of H2S diffusing upward. These isotopic compositions are, however, very different from the porewater SO4[2-] (+43 per mil) and H2S (-15 per mil) at the same depth. The model explains how methane-driven sulfate reduction combined with a deep H2S sink leads to isotopically heavy pyrite in a sediment open to diffusion. These results have general implications for the marine sulfur cycle and for the interpretation of sulfur isotopic data in modern sediments and in sedimentary rocks throughout earth's history.

‘Genetic Coding’ Reconsidered : An Analysis of Actual Usage

I thank George Pandarakalam for research assistance; Hans-Jörg Rheinberger for hosting my stay at the Max Planck Institute for History of Science, Berlin; and Sahotra Sarkar and referees of this journal for offering detailed comments. Funded by the Wellcome Trust (WT098764MA).

‘Genetic Coding’ Reconsidered : An Analysis of Actual Usage

I thank George Pandarakalam for research assistance; Hans-Jörg Rheinberger for hosting my stay at the Max Planck Institute for History of Science, Berlin; and Sahotra Sarkar and referees of this journal for offering detailed comments. Funded by the Wellcome Trust (WT098764MA).

A new stepwise carbon cycle data assimilation system using multiple data streams to constrain the simulated land surface carbon cycle

Acknowledgements. This work was mainly funded by the EU FP7 CARBONES project (contracts FP7-SPACE-2009-1-242316), with also a small contribution from GEOCARBON project (ENV.2011.4.1.1-1-283080). This work used eddy covariance data acquired by the FLUXNET community and in particular by the following networks: AmeriFlux (U.S. Department of Energy, Biological and Environmental Research, Terrestrial Carbon Program; DE-FG02-04ER63917 and DE-FG02-04ER63911), AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada (supported by CFCAS, NSERC, BIOCAP, Environment Canada, and NRCan), GreenGrass, KoFlux, LBA, NECC, OzFlux, TCOS-Siberia, USCCC. We acknowledge the financial support to the eddy covariance data harmonization provided by CarboEuropeIP, FAO-GTOS-TCO, iLEAPS, Max Planck Institute for Biogeochemistry, National Science Foundation, University of Tuscia, Université Laval and Environment Canada and US Department of Energy and the database development and technical support from Berkeley Water Center, Lawrence Berkeley National Laboratory, Microsoft Research eScience, Oak Ridge National Laboratory, University of California-Berkeley, University of Virginia. Philippe Ciais acknowledges support from the European Research Council through Synergy grant ERC-2013-SyG-610028 “IMBALANCE-P”. The authors wish to thank M. Jung for providing access to the GPP MTE data, which were downloaded from the GEOCARBON data portal (https://www.bgc-jena.mpg.de/geodb/projects/Data.php). The authors are also grateful to computing support and resources provided at LSCE and to the overall ORCHIDEE project that coordinate the development of the code (http://labex.ipsl.fr/orchidee/index.php/about-the-team).