5,850 research outputs found
FUSE/Lyman grant
A variety of options for a short wavelength spectrometer for the Lyman telescope has been studied, and the optimum configuration for this instrument identified. In this spectrometer option study it is assumed (consistent with performance goals outlined by the project) that the instrument, whose prime spectral domain is 900-12000A, will incorporate a grazing incidence telescope which will maintain good collecting efficiency down to 100A. In particular it is assumed that the telescope will have an effective focal length of 10 meters, an image quality of 1.5", and will provide a diverging f/10 beam. Designs compatible with this telescope are analyzed, and it is determined that a two-element grazing incidence spectrometer using as its first optic an ellipsoid to re-focus the beam and a varied line-space plane diffraction grating to disperse the light is the best overall design. This spectrometer could be fed by a small pick-off mirror located just behind the prime focus of the telescope and would clear the light path when not in use. A test of the diffraction efficiency of a low blaze angle grating is undertaken, which is the only technical uncertainty in the spectrometer design
Role of optimization in interdisciplinary analyses of naval structures
The need for numerical design optimization of naval structures is discussed. The complexity of problems that arise due to the significant roles played by three major disciplines, i.e., structural mechanics, acoustics, and hydrodynamics are discussed. A major computer software effort that has recently begun at the David W. Taylor Naval Ship R&D Center to accommodate large multidisciplinary analyses is also described. In addition to primarily facilitating, via the use of data bases, interdisciplinary analyses for predicting the response of the Navy's ships and related structures, this software effort is expected to provide the analyst with a convenient numerical workbench for performing large numbers of analyses that may be necessary for optimizing the design performance. Finally, an example is included that investigates several aspects of optimizing a typical naval structure from the viewpoints of strength, hydrodynamic form, and acoustic characteristics
Settler colonialism and white settler responsibility in the Karuk, Konomihu, Shasta, and New River Shasta Homelands: a white unsettling manifesto
Contributing to recent research into settler colonialism, this paper takes an on the ground look at how this system manifests today. This research turns its lens on the white settler, unmasks settler myths of innocence and contributes to an understanding of how whiteness and white supremacism shape settler colonialism in what is now called the United Sates. This is a placed based study, focusing on the Klamath and Salmon Rivers. Consequences and complexities of the “back to the land” movement are looked at, and the question of “back-to-whose-land?” is asked? A convivial research approach, which is a back and forth interplay of analysis and action, has been utilized for this project. Also examined are efforts by settlers to engage with unsettling, both as individuals and through a collective settler effort at organizing, under the name “Unsettling Klamath River.” Unsettling can be described as the work of white settlers within the broader movement to decolonize, that is led by Indigenous People. Some false narratives have begun to shift and yet, this population of white settlers remains largely in a state of paralysis due to; a fragile settler identity, a reliance on a false entitlement and a debilitating fear of what will happen if truth-telling occurs. Building upon lessons learned, this paper concludes by offering ways that white settlers can begin to chip away at oppressive structures and move forward out of a state of complicity into a sense of responsibility, that is long overdue
Motions Practice before the Board of Immigration Appeals
This Article addresses the area of motions practice before the Board of Immigration Appeals, arguing that it is often a complex procedural maze for immigration attorneys. The author examines the intricacies of this procedure, focusing on motions to reopen, motion to reconsider, motions to remand, and motions for stays of deportation. He further examines the often contested issues of the prima facia case, particularly in the context of motions to reopen. In this discussion, the author, an appellate trial lawyer for the Immigration and Naturalization Service, stresses the practical aspects of motions practice in this area
Normal mode splitting in a coupled system of nanomechanical oscillator and parametric amplifier cavity
We study how an optical parametric amplifier inside the cavity can affect the
normal mode splitting behavior of the coupled movable mirror and the cavity
field. We work in the resolved sideband regime. The spectra exhibit a
double-peak structure as the parametric gain is increased. Moreover, for a
fixed parametric gain, the double-peak structure of the spectrum is more
pronounced with increasing the input laser power. We give results for mode
splitting. The widths of the split lines are sensitive to parametric gain.Comment: 7 pages,9 figure
Structural change in multipartite entanglement sharing: a random matrix approach
We study the typical entanglement properties of a system comprising two
independent qubit environments interacting via a shuttling ancilla. The initial
preparation of the environments is modeled using random-matrix techniques. The
entanglement measure used in our study is then averaged over many histories of
randomly prepared environmental states. Under a Heisenberg interaction model,
the average entanglement between the ancilla and one of the environments
remains constant, regardless of the preparation of the latter and the details
of the interaction. We also show that, upon suitable kinematic and dynamical
changes in the ancilla-environment subsystems, the entanglement-sharing
structure undergoes abrupt modifications associated with a change in the
multipartite entanglement class of the overall system's state. These results
are invariant with respect to the randomized initial state of the environments.Comment: 10 pages, RevTeX4 (Minor typo's corrected. Closer to published
version
Financial Regret at Older Ages and Longevity Awareness
Older people often express regret about financial decisions made earlier in life that left them susceptible to old-age insecurity. Prior work has explored one outcome, saving regret, or peoples’ expressed wish that they had saved more earlier in life. The present paper extends attention to five additional areas regarding financial decisions, examining whether older Americans also regret not having insured better, claimed benefits and quit working too early, and becoming financially dependent on others. Using a controlled randomized experiment conducted on 1,764 respondents age 50+ in the Health and Retirement Study, we show that providing people objective longevity information does alter their self-reported financial regret. Specifically, giving people information about objective survival probabilities more than doubled regret expressed about not having purchased long term care, and it also boosted their regret by 2.4 times for not having purchased lifetime income. We conclude that information provision can be a potent, as well as cost-effective, method of alerting people to retirement risk
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