Experimental confirmation of long-memory correlations in star-wander data

In this letter we have analyzed the temporal correlations of the angle-of-arrival fluctuations of stellar images. Experimentally measured data were carefully examined by implementing multifractal detrended fluctuation analysis. This algorithm is able to discriminate the presence of fractal and multifractal structures in recorded time sequences. We have confirmed that turbulence-degraded stellar wavefronts are compatible with a long-memory correlated monofractal process. This experimental result is quite significant for the accurate comprehension and modeling of the atmospheric turbulence effects on the stellar images. It can also be of great utility within the adaptive optics field.Comment: 4 pages, 5 figures, 23 references. Minor grammatical changes to match the published version. Comments and suggestions are welcome

Multiscale permutation entropy analysis of laser beam wandering in isotropic turbulence

We have experimentally quantified the temporal structural diversity from the coordinate fluctuations of a laser beam propagating through isotropic optical turbulence. The main focus here is on the characterization of the long-range correlations in the wandering of a thin Gaussian laser beam over a screen after propagating through a turbulent medium. To fulfill this goal, a laboratory-controlled experiment was conducted in which coordinate fluctuations of the laser beam were recorded at a sufficiently high sampling rate for a wide range of turbulent conditions. Horizontal and vertical displacements of the laser beam centroid were subsequently analyzed by implementing the symbolic technique based on ordinal patterns to estimate the well-known permutation entropy. We show that the permutation entropy estimations at multiple time scales evidence an interplay between different dynamical behaviors. More specifically, a crossover between two different scaling regimes is observed. We confirm a transition from an integrated stochastic process contaminated with electronic noise to a fractional Brownian motion with a Hurst exponent H = 5/6 as the sampling time increases. Besides, we are able to quantify, from the estimated entropy, the amount of electronic noise as a function of the turbulence strength. We have also demonstrated that these experimental observations are in very good agreement with numerical simulations of noisy fractional Brownian motions with a well-defined crossover between two different scaling regimes.Comment: 8 pages, 6 figure

Relaxation dynamics of a protein solution investigated by dielectric spectroscopy

In the present work, we provide a dielectric study on two differently concentrated aqueous lysozyme solutions in the frequency range from 1 MHz to 40 GHz and for temperatures from 275 to 330 K. We analyze the three dispersion regions, commonly found in protein solutions, usually termed beta-, gamma-, and delta-relaxation. The beta-relaxation, occurring in the frequency range around 10 MHz and the gamma-relaxation around 20 GHz (at room temperature) can be attributed to the rotation of the polar protein molecules in their aqueous medium and the reorientational motion of the free water molecules, respectively. The nature of the delta-relaxation, which often is ascribed to the motion of bound water molecules, is not yet fully understood. Here we provide data on the temperature dependence of the relaxation times and relaxation strengths of all three detected processes and on the dc conductivity arising from ionic charge transport. The temperature dependences of the beta- and gamma-relaxations are closely correlated. We found a significant temperature dependence of the dipole moment of the protein, indicating conformational changes. Moreover we find a breakdown of the Debye-Stokes-Einstein relation in this protein solution, i.e., the dc conductivity is not completely governed by the mobility of the solvent molecules. Instead it seems that the dc conductivity is closely connected to the hydration shell dynamics.Comment: 11 pages, 7 figure

Turbulence-induced persistence in laser beam wandering

We have experimentally confirmed the presence of long-memory correlations in the wandering of a thin Gaussian laser beam over a screen after propagating through a turbulent medium. A laboratory-controlled experiment was conducted in which coordinate fluctuations of the laser beam were recorded at a sufficiently high sampling rate for a wide range of turbulent conditions. Horizontal and vertical displacements of the laser beam centroid were subsequently analyzed by implementingdetrended fluctuation analysis. This is a very well-known and widely used methodology to unveil memory effects from time series. Results obtained from this experimental analysis allow us to confirm that both coordinates behave as highly persistent signals for strong turbulent intensities. This finding is relevant for a better comprehension and modeling of the turbulence effects in free-space optical communication systems and other applications related to propagation of optical signals in the atmosphere

Building the Boilermakers’ Biking Infrastructure

The Integrated Bicycle and Pedestrian Infrastructure Plan, conceived in 2014, is guiding the development of a bicycle network to accommodate a safer environment for all modes of campus travel. As new dedicated paths are completed, opportunities for integrating academic and student life are emerging. Planning the bike share program, launched in 2015, requires understanding shifts in student travel throughout campus, safe and efficient riding, locating bike share stations, and connecting to adjacent communities. Join us for a discussion

Libros copiadores del Instituto de Física

Los Libros Copiadores son el registro de las notas oficiales emitidas por los directores del antiguo Instituto de Física de la UNLP y dan testimonio del comienzo de la física en Argentina.\nHemos estudiado, intervenido conservativamente y duplicado los de mayor antigüedad (1908-1933) pertenecientes al Archivo del Museo de Física (Departamento de Física, Facultad de Ciencias Exactas – UNLP) para preservar su información.\nLos estudios han hecho énfasis, en su primera etapa, en la composición de las tintas empleadas con el fin de establecer y aplicar tratamientos de conservación idóneos a cada ejemplar.\nLa composición de las tintas se determinó utilizando Fluorescencia de Rayos X, una técnica espectroscópica que permite la detección de elementos de número atómico mayor que doce. El análisis se realizó in-situ, directamente sobre la escritura de los cuadernos, mediante un ensayo de carácter no destructivo.\nLos resultados revelaron que la mayoría de las tintas usadas son del tipo Ferrogalotánicas, con aditivos de Cobre, trazas de Zinc y, en algunos casos, de Plomo. Esta información fue esencial para decidir la duplicación de los cuadernos con el propósito ineludible de preservar la información en ellos codificada mediante esa tinta.\nPara lograr ese fin fue necesario consolidar los libros que se hallaban en muy mal estado, con el papel y la tinta degradados debido a la corrosión ferrogalotánica. El método elegido fue el laminado, que posteriormente permitió la duplicación mediante fotografía digital y scanner.Eje 3: Exhibición y Conservació

Electrode Polarization Effects in Broadband Dielectric Spectroscopy

In the present work, we provide broadband dielectric spectra showing strong electrode polarization effects for various materials, belonging to very different material classes. This includes both ionic and electronic conductors as, e.g., salt solutions, ionic liquids, human blood, and colossal-dielectric-constant materials. These data are intended to provide a broad data base enabling a critical test of the validity of phenomenological and microscopic models for electrode polarization. In the present work, the results are analyzed using a simple phenomenological equivalent-circuit description, involving a distributed parallel RC circuit element for the modeling of the weakly conducting regions close to the electrodes. Excellent fits of the experimental data are achieved in this way, demonstrating the universal applicability of this approach. In the investigated ionically conducting materials, we find the universal appearance of a second dispersion region due to electrode polarization, which is only revealed if measuring down to sufficiently low frequencies. This indicates the presence of a second charge-transport process in ionic conductors with blocking electrodes.Comment: 9 pages, 6 figures, experimental data are provided in electronic form (see "Data Conservancy"

Impact of drug discount contracts on pharmacies and on patients' drug supply

Since April 2007, health insurance companies in Germany have been entitled to negotiate drug discount contracts (DDCs) with pharmaceutical manufacturers for particular drugs. DDCs commit pharmacists to dispense the drug made by this manufacturer. The aim of this study was to examine how DDCs are implemented in pharmacy routines and what implications DDCs have for the everday drug supply. Methods: A standardized questionnaire on DDCs and their impact on the drug supply was developed according to the previous literature, piloted and distributed to pharmacies in Baden-Württemberg. Results: Eight hundred four pharmacists and pharmaceutical assistants participated in the study. The implementation of DDCs implies significant extra work for pharmacists, particulary the additional need for customer counseling and education (99.1%), additional logistical requirements and more complex data processing needs. Patients are reported to get confused (97%) and angry (96.9%) about non-transparent drug substitutions, and medication errors occur (60.1%). Conclusion: DDCs, besides having implications for prescibers and patients, also have a substantial impact on pharmacists and pharmacies. Adverse effects on the drug supply and medication safety are possible or likely

Application of financial technologies in the banking system of Ukraine

The financial sector contributes to the growth of the population's well-being, stimulates business development, and helps to expand the markets for goods and services. With the passage of time, financial technologies are becoming more and more important, because after the global financial crisis, banking institutions were forced to adapt to new challenges. With the advent of the latest technologies, banks had to focus on the efficient provision of financial services, taking into account financial inclusion. In order to help consumers of financial services manage the financial aspects of business, while using new programs, financial technologies are used. They are a necessary mechanism for the formation of competitiveness of any company and any state. However, there is a problem of low involvement of the population in the financial sector, as not every individual has access to quality financial services and the necessary experience to use them in everyday life. Thus, the purpose of the article is research and analysis of the application of financial technologies in the banking system of Ukraine. The article examines the essence of financial technologies and their role in the development of the financial sphere of Ukraine. The question of the emergence of financial technologies is highlighted. It was considered how and with the help of which financial technologies the work of banking institutions is carried out during the COVID-19 pandemic. In order to determine the strengths and weaknesses, opportunities and threats, a SWOT analysis of the use of online technologies by banking institutions of Ukraine during the COVID-19 pandemic was conducted. It was found that there was an increase in demand among the fintech population, especially during the COVID-19 pandemi