3,223 research outputs found
A CCD image transducer and processor suitable for space flight
A satellite borne extreme ultraviolet solar telescope makes use of CCD area arrays for both image readout and onboard data processing. The instrument is designed to view the inner solar corona in the wavelength band 170 - 630 A, and the output video stream may be selected by ground command to present the coronal scene, or the time-rate-of-change of the scene. Details of the CCD application to onboard image processing are described, and a discussion of the processor's potential for telemetry bandwidth compression is included. Optical coupling methods, data storage requirements, spatial and temporal resolution, and nonsymmetry of resolution (pitch) in the CCD are discussed
On the General Analytical Solution of the Kinematic Cosserat Equations
Based on a Lie symmetry analysis, we construct a closed form solution to the
kinematic part of the (partial differential) Cosserat equations describing the
mechanical behavior of elastic rods. The solution depends on two arbitrary
analytical vector functions and is analytical everywhere except a certain
domain of the independent variables in which one of the arbitrary vector
functions satisfies a simple explicitly given algebraic relation. As our main
theoretical result, in addition to the construction of the solution, we proof
its generality. Based on this observation, a hybrid semi-analytical solver for
highly viscous two-way coupled fluid-rod problems is developed which allows for
the interactive high-fidelity simulations of flagellated microswimmers as a
result of a substantial reduction of the numerical stiffness.Comment: 14 pages, 3 figure
Solwind observations of coronal mass ejections during 1979-1985
Coronal observations have been processed for parts of each year during the interval 1979-1985. Around sunspot maximum, coronal mass ejections (CMEs) occurred at the rate of approximately 2 per day, and had a wide range of physical and morphological properties. During the recent years of relatively low sunspot number, CMEs occurred at the rate of only 0.2 per day, and were dominated by the class of so-called streamer blowout. These special CMEs maintained a nearly constant occurrence rate of roughly 0.1 per day during the entire interval
Associations between coronal mass ejections and interplanetary shocks
Nearly continuous complementary coronal observations and interplanetary plasma measurements for the years 1979-1982 are compared. It is shown that almost all low latitude high speed coronal mass ejections (CME's) were associated with shocks at HELIOS 1. Some suitably directed low speed CME's were clearly associated with shocks while others may have been associated with disturbed plasma (such as NCDE's) without shocks. A few opposite hemisphere CME's associated with great flares seem to be associated with shocks at HELIOS
Structure of hard-hypersphere fluids in odd dimensions
The structural properties of single component fluids of hard hyperspheres in
odd space dimensionalities are studied with an analytical approximation
method that generalizes the Rational Function Approximation earlier introduced
in the study of hard-sphere fluids [S. B. Yuste and A. Santos, Phys. Rev. A
{\bf 43}, 5418 (1991)]. The theory makes use of the exact form of the radial
distribution function to first order in density and extends it to finite
density by assuming a rational form for a function defined in Laplace space,
the coefficients being determined by simple physical requirements. Fourier
transform in terms of reverse Bessel polynomials constitute the mathematical
framework of this approximation, from which an analytical expression for the
static structure factor is obtained. In its most elementary form, the method
recovers the solution of the Percus-Yevick closure to the Ornstein-Zernike
equation for hyperspheres at odd dimension. The present formalism allows one to
go beyond by yielding solutions with thermodynamic consistency between the
virial and compressibility routes to any desired equation of state. Excellent
agreement with available computer simulation data at and is
obtained. As a byproduct of this study, an exact and explicit polynomial
expression for the intersection volume of two identical hyperspheres in
arbitrary odd dimensions is given.Comment: 18 pages, 7 figures; v2: new references added plus minor changes; to
be published in PR
Fabrication Of Steaks From Spent Hens
Research at SDSU has demonstrated that meat from spent laying hens (spent fowl) can be utilized in the production of fabricated steaks and/or roasts. Previous studies utilized raw meat from carcasses that were manually deboned. Under commercial deboning, meat that has been precooked is more easily separated from the bone. Precooking reduces the ability for meat to hold together or bind in a processed product. Precooked and raw spent fowl muscles were compared as raw material for the production of fabricated steaks. The objective of this research was to produce from precooked spent fowl muscle a palatable restructured product that will withstand handling, cooking and serving
EIT: Solar corona synoptic observations from SOHO with an Extreme-ultraviolet Imaging Telescope
The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and heliospheric observatory) will provide full disk images in emission lines formed at temperatures that map solar structures ranging from the chromospheric network to the hot magnetically confined plasma in the corona. Images in four narrow bandpasses will be obtained using normal incidence multilayered optics deposited on quadrants of a Ritchey-Chretien telescope. The EIT is capable of providing a uniform one arc second resolution over its entire 50 by 50 arc min field of view. Data from the EIT will be extremely valuable for identifying and interpreting the spatial and temperature fine structures of the solar atmosphere. Temporal analysis will provide information on the stability of these structures and identify dynamical processes. EIT images, issued daily, will provide the global corona context for aid in unifying the investigations and in forming the observing plans for SOHO coronal instruments
Anisometric mesoscale nuclear and magnetic texture in sintered Nd-Fe-B magnets
By means of temperature and wavelength-dependent small-angle neutron
scattering (SANS) experiments on sintered isotropic and textured Nd-Fe-B
magnets we provide evidence for the existence of an anisometric structure in
the microstructure of the textured magnets. This conclusion is reached by
observing a characteristic cross-shaped angular anisotropy in the total
unpolarized SANS cross section at temperatures well above the Curie
temperature. Comparison of the experimental SANS data to a microstructural
model based on the superquadrics form factor allows us to estimate the shape
and lower bounds for the size of the structure. Subtraction of the scattering
cross section in the paramagnetic regime from data taken at room temperature
provides the magnetic SANS cross section. Surprisingly, the anisotropy of the
magnetic scattering is very similar to the nuclear SANS signal, suggesting that
the nuclear structure is decorated by the magnetic moments via spin-orbit
coupling. Based on the computation of the two-dimensional correlation function
we estimate lower bounds for the longitudinal and transversal magnetic
correlation lengths
Substantial increases in healthcare students’ state empathy scores owing to participation in a single improvisation session
Purpose: To determine whether the 12-item state empathy scale could be modified reliably to measure empathy in healthcare professions students and to detect changes in their empathy owing to a single improvisation (improv) session. Methods: Three cohorts of students from two healthcare professions programs (total = 165 students) participated in an improv session. During the session, one of the researchers (BS) tasked the students with several improv activities. Participants’ self-reported state empathy scores were assessed at three time points (pre-improv, post-improv, and end of semester) using revised, in-class paper versions of the State Empathy Scale. Results: The exploratory factor analysis revealed a single factor solution for the revised scale, justifying the creation of an overall state empathy score from the questionnaire. Cronbach’s alpha reliability values averaged 0.87. Students’ mean empathy scores were higher directly after the improv session than directly prior to the session (p \u3c 0.0001; effect size = r = 0.67, 0.55, and 0.79 for cohorts 1, 2, and 3, respectively). Conclusions: These findings show that a single one- or two-hour improv session can foster substantial increases in healthcare professional students’ state empathy for one another. Greater healthcare professional empathy and compassion foster better healthcare team cooperation and patient outcomes, so healthcare professionals and their students should engage in such empathy-enhancing activities at regular intervals throughout their training and careers
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