38,018 research outputs found
A method for precision anodize stripping
Felt templates saturated with etch solution remove anodized finish from aluminum without damage to the surface. The solution is a combination of nitric acid, chromic acid, and hydrofluoric acid
Experiments and a model for pilot dynamics with visual and motion inputs
Multimodality pilot model for visual and motion feedbacks derived from simulator progra
Smoking, dementia and cognitive decline in the elderly, a systematic review.
Background. Nicotine may aid reaction time, learning and memory, but smoking increases cardiovascular risk. Cardiovascular risk factors have been linked to increased risk of dementia. A previous meta-analysis found that current smokers were at higher risk of subsequent dementia, Alzheimers disease, vascular dementia and cognitive decline. Methods. In order to update and examine this further a systematic review and meta-analysis was carried out using different search and inclusion criteria, database selection and more recent publications. Both reviews were restricted to those aged 65 and over. Results. The review reported here found a significantly increased risk of Alzheimers disease with current smoking and a likely but not significantly increased risk of vascular dementia, dementia unspecified and cognitive decline. Neither review found clear relationships with former smoking. Conclusion. Current smoking increases risk of Alzheimers disease and may increase risk of other dementias. This reinforces need for smoking cessation, particularly aged 65 and over. Nicotine alone needs further investigation. © 2008 Peters et al; licensee BioMed Central Ltd
Letter from Sierra States University Dean R. L. Peters to Enemy Alien Control Supervisor Edward G. Ennis regarding Richard Auras, 1942
A July 5, 1942 letter from Dean R. L. Peters of Sierra States University College of Chiropractic to Edward G. Ennis, the supervisor of Enemy Alien Control in Washington D.C. stating that Richard Auras was a student at SSU from March 1940 until December 1941 when the U.S. Federal Government interned him. Dean Peters adds that Auras was a good student and did not show signs of being an enemy alien.
See also:
Petition and Affidavit By Curt Benedict arguing for overturn of denial of release of Richard Auras from Internment, 1946
Letter from Richard Auras to William Langer regarding his internment status decision, 1946https://commons.und.edu/langer-papers/1157/thumbnail.jp
Capturing, using, and managing quality assurance knowledge for shuttle post-MECO flight design
Ascent initialization values used by the Shuttle's onboard computer for nominal and abort mission scenarios are verified by a six degrees of freedom computer simulation. The procedure that the Ascent Post Main Engine Cutoff (Post-MECO) group uses to perform quality assurance (QA) of the simulation is time consuming. Also, the QA data, checklists and associated rationale, though known by the group members, is not sufficiently documented, hindering transfer of knowledge and problem resolution. A new QA procedure which retains the current high level of integrity while reducing the time required to perform QA is needed to support the increasing Shuttle flight rate. Documenting the knowledge is also needed to increase its availability for training and problem resolution. To meet these needs, a knowledge capture process, embedded into the group activities, was initiated to verify the existing QA checks, define new ones, and document all rationale. The resulting checks were automated in a conventional software program to achieve the desired standardization, integrity, and time reduction. A prototype electronic knowledge base was developed with Macintosh's HyperCard to serve as a knowledge capture tool and data storage
Correcting turnover correlations: A critique
In this article, the authors argue that turnover correlations do not need to be corrected. First, they maintain that correction formulas cannot correct for poor construct validity. Second, they discuss the original purposes of turnover correction formulas. Third, the authors describe the logical fallacies of correcting turnover correlations. Finally, they show why turnover correlations are not, as is widely believed, statistically limited to a maximum of .80
Numerical Simulation of the Hydrodynamical Combustion to Strange Quark Matter
We present results from a numerical solution to the burning of neutron matter
inside a cold neutron star into stable (u,d,s) quark matter. Our method solves
hydrodynamical flow equations in 1D with neutrino emission from weak
equilibrating reactions, and strange quark diffusion across the burning front.
We also include entropy change due to heat released in forming the stable quark
phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04
times the speed of light, much faster than previous estimates derived using
only a reactive-diffusive description. Analytic solutions to hydrodynamical
jump conditions with a temperature dependent equation of state agree very well
with our numerical findings for fluid velocities. The most important effect of
neutrino cooling is that the conversion front stalls at lower density (below
approximately 2 times saturation density). In a 2-dimensional setting, such
rapid speeds and neutrino cooling may allow for a flame wrinkle instability to
develop, possibly leading to detonation.Comment: 5 pages, 3 figures (animations online at
http://www.capca.ucalgary.ca/~bniebergal/webPHP/research.php
Spin effects in gravitational radiation backreaction II. Finite mass effects
A convenient formalism for averaging the losses produced by gravitational
radiation backreaction over one orbital period was developed in an earlier
paper. In the present paper we generalize this formalism to include the case of
a closed system composed from two bodies of comparable masses, one of them
having the spin S.
We employ the equations of motion given by Barker and O'Connell, where terms
up to linear order in the spin (the spin-orbit interaction terms) are kept. To
obtain the radiative losses up to terms linear in the spin, the equations of
motion are taken to the same order. Then the magnitude L of the angular
momentum L, the angle kappa subtended by S and L and the energy E are
conserved. The analysis of the radial motion leads to a new parametrization of
the orbit.
From the instantaneous gravitational radiation losses computed by Kidder the
leading terms and the spin-orbit terms are taken. Following Apostolatos,
Cutler, Sussman and Thorne, the evolution of the vectors S and L in the
momentary plane spanned by these vectors is separated from the evolution of the
plane in space. The radiation-induced change in the spin is smaller than the
leading-order spin terms in the momentary angular momentum loss. This enables
us to compute the averaged losses in the constants of motion E, L and L_S=L cos
kappa. In the latter, the radiative spin loss terms average to zero. An
alternative description using the orbital elements a,e and kappa is given.
The finite mass effects contribute terms, comparable in magnitude, to the
basic, test-particle spin terms in the averaged losses.Comment: 12 pages, 1 figure, Phys.Rev.D15, March, 199
Returning to Graduate School: Expectations of Success, Values of the Degree, and Managing the Costs
Background Limited research exists on the experiences of engineering returners – those with undergraduate degrees who work for at least five years and return to academia for graduate degrees. Returners bring a different perspective to their graduate studies and postgraduate work than direct‐pathway students but face additional challenges. Purpose Our aim was to understand practitioners' decisions to return to graduate school and complete graduate degrees. Guided by expectancy value theory, we investigated their beliefs about their ability to succeed; the interest, attainment, and utility values returners placed on graduate school; the costs they experienced in returning; and the personal, programmatic, and cultural factors that mitigated these costs. Design/Method We employed a qualitative interpretivist approach to investigate the returning experience through semi‐structured interviews with 10 returners. We analyzed the results deductively, using expectancy value theory to understand participants' expectations of success and the values of those experiences, and inductively, to understand the types of costs that influenced the decision to return and complete graduate school. Results Utility value drove participants' decisions to return and complete graduate programs, and participants had a high expectancy of success in earning their graduate degrees. Four types of costs emerged from analysis of the interviews: intellectual, balance, cultural and environmental, and financial. Participants employed various strategies to mitigate these costs. Conclusions With the results of our study, potential returners can more effectively plan for success in the graduate environment, and universities can develop initiatives to better recruit returners and support their success.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99102/1/jee20012.pd
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