560 research outputs found

    Effects of the second virial coefficient on the adiabatic lapse rate of dry atmospheres

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    We study the effect of the second virial coefficient on the adiabatic lapse rate of a dry atmosphere. To this end, we compute the corresponding adiabatic curves, the internal energy, and the heat capacity, among other thermodynamic parameters. We apply these results to Earth, Mars, Venus, Titan, and the exoplanet G1 851d, considering three physically relevant virial coefficients in each case: the hard-sphere, van der Waals, and the square-well potential. These examples illustrate under which atmospheric conditions the effect of the second virial coefficient is relevant. Taking the latter into account yields corrections towards the experimental values of the lapse rates of Venus and Titan in some instances.Comment: 12 pages, 8 figures. Comments are welcom

    Classical analogs of generalized purities, entropies, and logarithmic negativity

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    It has recently been proposed classical analogs of the purity, linear quantum entropy, and von Neumann entropy for classical integrable systems, when the corresponding quantum system is in a Gaussian state. We generalized these results by providing classical analogs of the generalized purities, Bastiaans-Tsallis entropies, R\'enyi entropies, and logarithmic negativity for classical integrable systems. These classical analogs are entirely characterized by the classical covariance matrix. We compute these classical analogs exactly in the cases of linearly coupled harmonic oscillators, a generalized harmonic oscillator chain, and a one-dimensional circular lattice of oscillators. In all of these systems, the classical analogs reproduce the results of their quantum counterparts whenever the system is in a Gaussian state. In this context, our results show that quantum information of Gaussian states can be reproduced by classical information.Comment: 17 pages. 9 figure

    Dr. Mary Edwards Walker: years ahead of her time.

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    Women phsycians in the United States were virtually nonexistent in the early to mid-1800s. Traditional medical schools still did not accept women, and few secretarian or eclectic medical schools were beginning to open their doors to female students. In 1849 at Geneva College, Elizabeth Blackwell became the first woman to achieve a medical degree in the United States.1 At the time of the Civil War, the few women who had managed to obtain medical degrees mainly served as nurses in the war, because society was not yet ready to accept the female physician.2 Dr. Mary Edwards Walker would help change the role of women physicians, becoming not only a valuable surgeon for the Union Army, but also a catalyst for the introduction and advancement of women in medicine

    Adiabatic lapse rate of real gases

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    We derive a formula for the dry adiabatic lapse rate of atmospheres composed of real gases. We restrict our study to those described by a family of two-parameter cubic equations of state and the recent Guevara-Rodríguez noncubic equation. Since our formula depends on the adiabatic curves, we compute them all at once, considering molecules that can move, rotate, and vibrate, for any equation of state. To illustrate our results, we estimate the lapse rate of the troposphere of Titan, obtaining a better approximation to the observed data in some instances, when compared to the estimation provided by the virial expansion up to the third order.B.D. acknowledges support from the CONEX-Plus programme funded by the Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under Marie Sklodowska-Curie Grant No. 801538. J.E.R. acknowledges financial support from the Consejo de Ciencia y Tecnología del Estado de Puebla. This work has been supported by the Spanish Ministerio de Ciencia Innovación y Universidades-Agencia Estatal de Investigación under Grant No. PID2020-116567GB-C22

    Edge observables of the Maxwell-Chern-Simons theory

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    We analyze the Lagrangian and Hamiltonian formulations of the Maxwell-Chern-Simons theory defined on a manifold with boundary for two different sets of boundary equations derived from a variational principle. We pay special attention to the identification of the infinite chains of boundary constraints and their resolution. We identify edge observables and their algebra (which corresponds to the well-known U(1)U(1) Kac-Moody algebra). Without performing any gauge fixing, and using the Hodge-Morrey theorem, we solve the Hamilton equations whenever possible. In order to give explicit solutions, we consider the particular case in which the fields are defined on a 22-disk. Finally, we study the Fock quantization of the system and discuss the quantum edge observables and states.Comment: 23 page

    Structure of the medium formed in heavy ion collisions

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    We investigate the structure of the medium formed in heavy ion collisions using three different models: the Color String Percolation Model (CSPM), the Core-Shell-Color String Percolation Model (CSCSPM), and the Color Glass Condensate (CGC) framework. We analyze the radial distribution function of the transverse representation of color flux tubes in each model to determine the medium's structure. Our results indicate that the CSPM behaves as an ideal gas, while the CSCSPM exhibits a structural phase transition from a gas-like to a liquid-like structure. Additionally, our analysis of the CGC framework suggests that it produces systems that behave like interacting gases for AuAu central collisions at RHIC energies and liquid-like structures for PbPb central collisions at LHC energies.Comment: 15 pages, 8 figure

    Sternal pain after rigid fixation: a pilot study of randomization rigid vs conventional wire closure.

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    Objective: Rigid sternal fixation may provide better sternal closure than conventional sternal wire closure. We performed a prospective randomized study to investigate if rigid closure reduces postoperative sternal pain. Methods: Patients undergoing CABG ± valve surgery between July 2011 and January 2012 were prospectively randomized into conventional wire closure (group C) or rigid fixation using sternal plates (group R). Pain scores were determined at 6 AM using a numeric rating scale (0 no pain, 5 moderate pain, 10 worst possible pain). Narcotic pain medication requirement from day 1 to 5 was collected and converted into intravenous morphine equivalent. Results: Among the total of 26 patients, 11 patients were in Group R (10 male and 1 female, age 67 ± 8.0) and 15 patients were in Group C (13 male and 2 female, age 66 ± 9.9). Preoperative risk factors and procedure were identical between the two groups. Pain scores were not significantly different between 2 groups. Narcotic requirement was smaller in group R (15.7 mg intravenous morphine equivalent in group R in day 1vs 18.4 mg intravenous morphine equivalent in day 1 in group C in day 1, 13.1 mg vs 12.5 mg in day 2, 9.4 mg vs 10.5 mg in day 3, 6.9 mg vs 7.7 mg in day 4, and 6.2 mg vs 6.9 mg in day 5) than group C. Total iv narcotic given over 5 days was 24 ± 41 mg in group R and 34 mg ± 54 mg in group C (p=0.60). Conclusion: Randomized data rom this ongoing study showed a trend of fewer narcotic requirement especially intravenous narcotics in group R than in group C. Implications: Rigid fixation may potentially improve immediate sternal pain after open heart surgery. Less narcotic requirement potentially facilitate early return to the daily activity
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