Wavelet-based Faraday Rotation Measure Synthesis

Faraday Rotation Measure (RM) Synthesis, as a method for analyzing multi-channel observations of polarized radio emission to investigate galactic magnetic fields structures, requires the definition of complex polarized intensity in the range of the negative lambda square. We introduce a simple method for continuation of the observed complex polarized intensity into this domain using symmetry arguments. The method is suggested in context of magnetic field recognition in galactic disks where the magnetic field is supposed to have a maximum in the equatorial plane. The method is quite simple when applied to a single Faraday-rotating structure on the line of sight. Recognition of several structures on the same line of sight requires a more sophisticated technique. We also introduce a wavelet-based algorithm which allows us to consider a set of isolated structures. The method essentially improves the possibilities for reconstruction of complicated Faraday structures using the capabilities of modern radio telescopes.Comment: 5 pages, 5 figures, accepted for publication in MNRAS Letter

What Can We Learn From the Existing Evidence of the Business Case for Investments in Nursing Care: Importance of Content, Context, and Policy Environment

Decisions of health care institutions to invest in nursing care are often guided by mixed and conflicting evidence of effects of the investments on organizational function and sustainability. This paper uses new evidence generated through Interdisciplinary Nursing Quality Research Initiative (INQRI)-funded research and published in peer-reviewed journals, to illustrate where the business case for nursing investments stands and to discuss factors that may limit the existing evidence and its transferability into clinical practice. We conclude that there are 3 limiting factors: (1) the existing business case for nursing investments is likely understated due to the inability of most studies to capture spillover and long-run dynamic effects, thus causing organizations to forfeit potentially viable nursing investments that may improve long-term financial stability; (2) studies rarely devote sufficient attention to describing the content and the organization-specific contextual factors, thus limiting generalizability; and (3) fragmentation of the current health care delivery and payment systems often leads to the financial benefits of investments in nursing care accruing outside of the organization incurring the costs, thus making potentially quality-improving and cost-saving interventions financially unattractive from the organization\u27s perspective. The payment reform, with its emphasis on high-quality affordable patient-centered care, is likely to strengthen the business case for investments in nursing care. Methodologically rigorous approaches that focus on broader societal implications of investments in nursing care, combined with a thorough understanding of potential barriers and facilitators of nursing change, should be an integral part of future research and policy efforts

Optimal control theory investigation of proprotor/wing response to vertical gust

Optimal control theory is used to design linear state variable feedback to improve the dynamic characteristics of a rotor and cantilever wing representing the tilting proprotor aircraft in cruise flight. The response to a vertical gust and system damping are used as criteria for the open and closed loop performance. The improvement in the dynamic characteristics achievable is examined for a gimballed rotor and for a hingeless rotor design. Several features of the design process are examined, including: (1) using only the wing or only the rotor dynamics in the control system design; (2) the use of a wing flap as well as the rotor controls for inputs; (3) and the performance of the system designed for one velocity at other forward speeds

Long-time behavior of MHD shell models

The long time behavior of velocity-magnetic field alignment is numerically investigated in the framework of MHD shell model. In the stationary forced case, the correlation parameter C displays a nontrivial behavior with long periods of high variability which alternates with periods of almost constant C. The temporal statistics of correlation is shown to be non Poissonian, and the pdf of constant sign periods displays clear power law tails. The possible relevance of the model for geomagnetic dynamo problem is discussed.Comment: 6 pages with 5 figures. In press on Europhysics Letter

Spectral function at high missing energies and momenta

The nuclear spectral function at high missing energies and momenta has been determined from a self-consistent calculation of the Green's function in nuclear matter using realistic nucleon-nucleon interactions. The results are compared with recent experimental data derived from ($e,e'p$) reactions on $^{12}C$. A rather good agreement is obtained if the Green's functions are calculated in a non-perturbative way.Comment: 10 pages, 3 figure

Screw dynamo in a time-dependent pipe flow

The kinematic dynamo problem is investigated for the flow of a conducting fluid in a cylindrical, periodic tube with conducting walls. The methods used are an eigenvalue analysis of the steady regime, and the three-dimensional solution of the time-dependent induction equation. The configuration and parameters considered here are close to those of a dynamo experiment planned in Perm, which will use a torus-shaped channel. We find growth of an initial magnetic field by more than 3 orders of magnitude. Marked field growth can be obtained if the braking time is less than 0.2 s and only one diverter is used in the channel. The structure of the seed field has a strong impact on the field amplification factor. The generation properties can be improved by adding ferromagnetic particles to the fluid in order to increase its relative permeability,but this will not be necessary for the success of the dynamo experiment. For higher magnetic Reynolds numbers, the nontrivial evolution of different magnetic modes limits the value of simple `optimistic' and `pessimistic' estimates.Comment: 10 pages, 12 figure