Stellar wind-magnetosphere interaction at exoplanets: computations of auroral radio powers

We present calculations of the auroral radio powers expected from exoplanets with magnetospheres driven by an Earth-like magnetospheric interaction with the solar wind. Specifically, we compute the twin cell-vortical ionospheric flows, currents, and resulting radio powers resulting from a Dungey cycle process driven by dayside and nightside magnetic reconnection, as a function of planetary orbital distance and magnetic field strength. We include saturation of the magnetospheric convection, as observed at the terrestrial magnetosphere, and we present power law approximations for the convection potentials, radio powers and spectral flux densities. We specifically consider a solar-age system and a young (1 Gyr) system. We show that the radio power increases with magnetic field strength for magnetospheres with saturated convection potential, and broadly decreases with increasing orbital distance. We show that the magnetospheric convection at hot Jupiters will be saturated, and thus unable to dissipate the full available incident Poynting flux, such that the magnetic Radiometric Bode's Law (RBL) presents a substantial overestimation of the radio powers for hot Jupiters. Our radio powers for hot Jupiters are $\sim$5-1300 TW for hot Jupiters with field strengths of 0.1-10 $B_J$ orbiting a Sun-like star, while we find that competing effects yield essentially identical powers for hot Jupiters orbiting a young Sun-like star. However, in particular for planets with weaker magnetic fields our powers are higher at larger orbital distances than given by the RBL, and there are many configurations of planet that are expected to be detectable using SKA.Comment: Accepted for publication in Mon. Not. R. Astron. So

Seeding systems for use with a laser velocimeter in large scale wind tunnels

Three seeding systems have been used in the 4- by 7- Meter Tunnel at NASA Langley Research Center: Kerosene smoke, solid particle dry dispersing, and solid particle liquid dispersing. It is anticipated that the liquid dispersing system will be used in all future applications at this facility because: (1) it has a steady output; (2) it is easy to operate and reconfigure; and, (3) it delivers particles of near uniform size

Boundary changing operators in the O(n) matrix model

We continue the study of boundary operators in the dense O(n) model on the random lattice. The conformal dimension of boundary operators inserted between two JS boundaries of different weight is derived from the matrix model description. Our results are in agreement with the regular lattice findings. A connection is made between the loop equations in the continuum limit and the shift relations of boundary Liouville 3-points functions obtained from Boundary Ground Ring approach.Comment: 31 pages, 4 figures, Introduction and Conclusion improve

Tuning electronic structures via epitaxial strain in Sr2IrO4 thin films

We have synthesized epitaxial Sr2IrO4 thin-films on various substrates and studied their electronic structures as a function of lattice-strains. Under tensile (compressive) strains, increased (decreased) Ir-O-Ir bond-angles are expected to result in increased (decreased) electronic bandwidths. However, we have observed that the two optical absorption peaks near 0.5 eV and 1.0 eV are shifted to higher (lower) energies under tensile (compressive) strains, indicating that the electronic-correlation energy is also affected by in-plane lattice-strains. The effective tuning of electronic structures under lattice-modification provides an important insight into the physics driven by the coexisting strong spin-orbit coupling and electronic correlation.Comment: 9 pages, 5 figures, 1 tabl

Weak Hopf algebras corresponding to Cartan matrices

We replace the group of group-like elements of the quantized enveloping algebra $U_q({\frak{g}})$ of a finite dimensional semisimple Lie algebra ${\frak g}$ by some regular monoid and get the weak Hopf algebra ${\frak{w}}_q^{\sf d}({\frak g})$. It is a new subclass of weak Hopf algebras but not Hopf algebras. Then we devote to constructing a basis of ${\frak{w}}_q^{\sf d}({\frak g})$ and determine the group of weak Hopf algebra automorphisms of ${\frak{w}}_q^{\sf d}({\frak g})$ when $q$ is not a root of unity.Comment: 21 page

Performance of differenced range data types in Voyager navigation

Voyager radio navigation made use of a differenced rage data type for both Saturn encounters because of the low declination singularity of Doppler data. Nearly simultaneous two-way range from two-station baselines was explicitly differenced to produce this data type. Concurrently, a differential VLBI data type (DDOR), utilizing doubly differenced quasar-spacecraft delays, with potentially higher precision was demonstrated. Performance of these data types is investigated on the Jupiter-to-Saturn leg of Voyager 2. The statistics of performance are presented in terms of actual data noise comparisons and sample orbit estimates. Use of DDOR as a primary data type for navigation to Uranus is discussed

Aerodynamic Characteristics of Blunt Bodies

Aerodynamic characteristics of blunt bodie

Equivalences between spin models induced by defects

The spectrum of integrable spin chains are shown to be independent of the ordering of their spins. As an application we introduce defects (local spin inhomogeneities in homogenous chains) in two-boundary spin systems and, by changing their locations, we show the spectral equivalence of different boundary conditions. In particular we relate certain nondiagonal boundary conditions to diagonal ones.Comment: 14 pages, 16 figures, LaTeX, Extended versio

Outer jet X-ray and radio emission in R Aquarii: 1999.8 to 2004.0

Chandra and VLA observations of the symbiotic star R Aqr in 2004 reveal significant changes over the three to four year interval between these observations and previous observations taken with the VLA in 1999 and with Chandra in 2000. This paper reports on the evolution of the outer thermal X-ray lobe-jets and radio jets. The emission from the outer X-ray lobe-jets lies farther away from the central binary than the outer radio jets, and comes from material interpreted as being shock heated to ~10^6 K, a likely result of collision between high speed material ejected from the central binary and regions of enhanced gas density. Between 2000 and 2004, the Northeast (NE) outer X-ray lobe-jet moved out away from the central binary, with an apparent projected motion of ~580 km s^-1. The Southwest (SW) outer X-ray lobe-jet almost disappeared between 2000 and 2004, presumably due to adiabatic expansion and cooling. The NE radio bright spot also moved away from the central binary between 2000 and 2004, but with a smaller apparent velocity than of the NE X-ray bright spot. The SW outer lobe-jet was not detected in the radio in either 1999 or 2004. The density and mass of the X-ray emitting material is estimated. Cooling times, shock speeds, pressure and confinement are discussed.Comment: 23 pages, 8 figure

Stress and Burnout in Nurse Leaders

Problem: Nurse leaders commonly experience stress and self-reported burnout. The associated negative consequences are compelling, yet few studies to date consider the nurse leader population. Stress is “a multidimensional phenomenon determined by a person’s perceptions and may be assessed as harm, loss, threat, or challenge” (Udod, Cummings, Care, & Jenkins, 2017a, p. 160). Burnout is a lack of professional fulfillment caused by emotional, physical, and psychological stress (Nurse Burnout, 2019). Drivers are associated and contributing factors which lead to stress and self-reported burnout. Purpose: The purposes of this correlational study are to (a) identify drivers from the literature and adapt an existing model to nurse leader populations, (b) investigate associations between drivers of stress among two nurse leader groups: Nurse Mangers/Nurse Supervisors and Chief Nursing Officers/Nurse Directors, (c) investigate association between drivers and self-reported burnout among all nurse leaders, and (d) compare drivers identified in the literature to drivers from the Minnesota Organization of Leaders in Nursing (MOLN) study. Conceptual Framework: The Job Demands-Resources (JD-R) Model of Burnout guided the literature review. We adapted our own model on stress leading to burnout in nurse leaders entitled Johnson, Nichols, and Sakhitab (JNS) Model of Stress Leading to Burnout in Nurse Leaders. The focus of the JNS model was to identify the drivers of stress leading to burnout in nurse leaders. Literature Search: Eight drivers of stress leading to burnout from the literature were: administrative duties, organizational constraints, role overload, lack of control, preparation, personal characteristics, quality patient care, and social support. Methods Data Analysis: The research method used for this thesis was a secondary analysis of the 2018 MOLN and the Minnesota Hospital Association Nurse Leader Burnout Survey. The Pearson product-moment correlation was used to assess relationships between drivers, stress, and burnout. The total sample included 210 nurse leaders. Results Data Analysis: Results from this secondary analysis found statistically significant drivers of stress in Nurse Managers and Nurse Supervisors (n = 90) were time (r = -.500, p = .000), control (r = -.321, p = .002), and resources (r = -.254, p = .016). The statistically significant drivers of stress in Chief Nursing Officers and Nurse Directors (n = 74) were time (r = -.492, p \u3c .000), resources (r = -.441, p = .000) control (r = -.387, p = .001), team efficiency (r = -.338, p = .003), and autonomy (r = -.250, p =.031). Drivers of self-reported burnout in nurse leaders (n = 210) in order of correlational strength were control, time, autonomy, resources, appreciation, team efficiency, value and quality (-.419 \u3c r \u3c -.181, p ≤ .009). Implications for Practice: Nurse leaders carry a high degree of responsibility and are unable to achieve optimal work/life balance. One solution is to restructure leadership hierarchy to include a co-manager role. A second implication for practice relates to the lack of control driver of stress; nurse leaders desire the freedom, empowerment, and autonomy to make decisions without fear for retribution. Lastly, an implication for practice relates to the drivers of social support and appreciation. It will be prudent for health care administrators to re-focus energies on provision of appreciation and recognition to nurse leaders. Implications for Research: The gap in longitudinal designed studies creates an opportunity for future research. We recommend replicating the MOLN study longitudinally and nationally to support findings from this secondary analysis. Future studies focusing on self-reported burnout need a standardized measurement tool. This will allow for direct comparison of data and stronger analysis of findings. Lastly, drivers of stress leading to burnout in nurse leaders must be universally defined