Polytropic Behavior of Solar Wind Protons Observed by Parker Solar Probe

A polytropic process describes the transition of a fluid from one state to another through a specific relationship between the fluid density and temperature. The value of the polytropic index that governs this relationship determines the heat transfer and the effective degrees of freedom during the process. In this study, we analyze solar wind proton plasma measurements, obtained by the Faraday cup instrument on-board Parker Solar Probe. We examine the large-scale variations of the proton plasma density and temperature within the inner heliosphere explored by the spacecraft. We also address a polytropic behavior in the density and temperature fluctuations in short-time intervals, which we analyze in order to derive the effective polytropic index of small time-scale processes. The large-scale variations of the solar wind proton density and temperature which are associated with the plasma expansion through the heliosphere, follow a polytropic model with a polytropic index ~5/3. On the other hand, the short time-scale fluctuations which may be associated with turbulence, follow a model with a larger polytropic index. We investigate possible correlations between the polytropic index of short time-scale fluctuations and the plasma speed, plasma beta, and the magnetic field direction. We discuss the scenario of mechanisms including energy transfer or mechanisms that restrict the particle effective degrees of freedom.Comment: 20 pages, 9 figure

Ain\u27t it Funny : That Easy, Squeezin\u27, Teasy, Pleasin\u27, Ragtime

https://digitalcommons.library.umaine.edu/mmb-vp/4147/thumbnail.jp

In My Dreamy Panama

https://digitalcommons.library.umaine.edu/mmb-vp/6070/thumbnail.jp

Sweetie Be Kind To Me

https://digitalcommons.library.umaine.edu/mmb-vp/4066/thumbnail.jp

Influence of detector motion in entanglement measurements with photons

We investigate how the polarization correlations of entangled photons described by wave packets are modified when measured by moving detectors. For this purpose, we analyze the Clauser-Horne-Shimony-Holt Bell inequality as a function of the apparatus velocity. Our analysis is motivated by future experiments with entangled photons designed to use satellites. This is a first step towards the implementation of quantum information protocols in a global scale

New Records of Vascular Plants in the Yukon Territory VIII

Forty-seven taxa, 35 native and 12 introduced, are reported as new to the flora of Yukon and nine taxa previously reported are deleted. The new native taxa are: Artemisia arctica ssp. comata, Botrychium alaskense, Botrychium minganense, Bromus richardsonii, Calamagrostis holmii, Carex incurviformis, Carex mackenziei, Carex microchaeta ssp. nesophila, Carex ramenskii, Carex rariflora var. androgyna, Carex tahoensis, Carex xerantica, Carex × flavicans, Deschampsia sukatschewii, Eleocharis erythropoda, Eleocharis macrostachya, Eleocharis mamillata, Erigeron ochroleucus, Impatiens noli-tangere, Limnorchis huronensis, Nymphaea tetragona, Polygonum douglasii ssp. douglasii, Potamogeton natans, Potentilla crebridens ssp. hemicryophila, Puccinellia tenella ssp. langeana, Rumex beringensis, Salix farriae, Salix glauca ssp. Stipuli fera, Saussurea nuda, Saxifraga hyperborea, Saxifraga rivularis ssp. arctolitoralis, Silene soczavana var. macrosperma, Symphyotrichum subspicatum, Taraxacum hyparcticum, and Zannichellia palustris. The new introduced taxa are: Acer negundo, Avena fatua, Camelina microcarpa, Crepis capillaris, Hippophae rhamnoides, Lamium amplexicaule, Linaria dalmatica, Medicago lupulina, Prunus padus, Rumex pseudonatronatus, Valeriana officinale, and Viola tricolor. Deleted taxa are: Aster laevis var. geyeri, Carex athrostachya, Elatine triantha, Camelina sativa, Erysimum cheiri, Galium palustre, Impatiens capensis, Platanthera hyperborea, and Sonchus oleraceus. Vouchers are cited and general notes on distribution and identification are provided. Four of the native taxa reported here are new to Canada: Botrychium alaskense, Carex microchaeta ssp. nesophila, Potentilla crebridens ssp. hemicryophila and Rumex beringensis

Heart failure and excess mortality after aortic valve replacement in aortic stenosis

INTRODUCTION: In aortic stenosis (AS), the heart transitions from adaptive compensation to an AS cardiomyopathy and eventually leads to decompensation with heart failure. Better understanding of the underpinning pathophysiological mechanisms is required in order to inform strategies to prevent decompensation. AREAS COVERED: In this review, we therefore aim to appraise the current pathophysiological understanding of adaptive and maladaptive processes in AS, appraise potential avenues of adjunctive therapy before or after AVR and highlight areas of further research in the management of heart failure post AVR. EXPERT OPINION: Tailored strategies for the timing of intervention accounting for individual patient's response to the afterload insult are underway, and promise to guide better management in the future. Further clinical trials of adjunctive pharmacological and device therapy to either cardioprotect prior to intervention or promote reverse remodelling and recovery after intervention are needed to mitigate the risk of heart failure and excess mortality

On the formation of glycolaldehyde in dense molecular cores

Glycolaldehyde is a simple monosaccharide sugar linked to prebiotic chemistry. Recently, it was detected in a molecular core in the star-forming region G31.41+0.31 at a reasonably high abundance. We investigate the formation of glycolaldehyde at 10 K to determine whether it can form efficiently under typical dense core conditions. Using an astrochemical model, we test five different reaction mechanisms that have been proposed in the astrophysical literature, finding that a gas-phase formation route is unlikely. Of the grain-surface formation routes, only two are efficient enough at very low temperatures to produce sufficient glycolaldehyde to match the observational estimates, with the mechanism culminating in CH3OH + HCO being favored. However, when we consider the feasibility of these mechanisms from a reaction chemistry perspective, the second grain-surface route looks more promising, H3CO + HCO

Mechanical squeezing via fast continuous measurement

We revisit quantum state preparation of an oscillator by continuous linear position measurement. Quite general analytical expressions are derived for the conditioned state of the oscillator. Remarkably, we predict that quantum squeezing is possible outside of both the backaction dominated and quantum coherent oscillation regimes, relaxing experimental requirements even compared to ground-state cooling. This provides a new way to generate non-classical states of macroscopic mechanical oscillators, and opens the door to quantum sensing and tests of quantum macroscopicity at room temperature